Use of spatial statistics and isotopic tracers to measure the influence of arsenical pesticide use on stream sediment chemistry in New England, USA

USGS Publications Warehouse

Robinson, G.R.; Ayuso, R.A.

2004-01-01

Arsenical pesticides and herbicides, principally Pb arsenate, Ca arsenate, and Na arsenate with lesser use of other metal-As pesticides, were widely applied on apple, blueberry, and potato crops in New England during the first half of the twentieth century. Agricultural census data for this time period is used to define an agricultural index that identifies areas that are inferred to have used arsenical pesticides extensively. Factor analysis on metal concentrations in 1597 stream sediment samples collected throughout New England, grouped by agricultural-index categories, indicate a positive association of areas with stream sediment sample populations that contain higher As and Pb concentrations than samples from the region as a whole with sample site settings having high agricultural-index values. Population statistics for As and Pb concentrations and factor scores for an As-Pb factor all increase systematically and significantly with increasing agricultural-index intensity in the region, as tested by Kruskal-Wallis analysis. Lead isotope compositions for 16 stream sediments from a range of agricultural-index settings generally overlap the observed variation in rock sulfides and their weathering products; however, sediments collected from high agricultural-index settings have slightly more radiogenic Pb compositions, consistent with an industrial Pb contribution to these samples. Although weathering products from rocks are likely to be the dominant source of As and metals to most of the stream sediment samples collected in the region, the widespread use of arsenical pesticides and herbicides in New England during the early 1900-1960s appears to be a significant anthropogenic source of As and metals to many sediments in agricultural areas in the region and has raised background levels of As in some regions. Elevated concentrations of As in stream sediments are of concern for two reasons. Stream sediments with elevated As concentrations delineate areas with elevated background concentrations of As from both natural rock and anthropogenic sources that may contribute As to groundwater systems used for drinking water supplies. Conversion of agricultural land contaminated with arsenical pesticide residues to residential development may increase the likelihood that humans will be exposed to As. In addition, many stream sediment sites have As concentrations that exceed sediment quality guidelines established for freshwater ecosystems. Thirteen percent of the New England sediment sample sites exceed 9.79 mg/kg As, the threshold effects concentration (TEC), below which harmful effects are unlikely to be observed. Arsenic concentrations exceed 33 mg/kg, the probable effects concentration (PEC), above which harmful effects on sediment-dwelling organisms are expected to occur frequently, at 1.25% of the sediment sample sites. The sample sites that exceed the PEC value occur predominately in agricultural areas that used arsenical pesticides.

Electrothermal adsorption and desorption of volatile organic compounds on activated carbon fiber cloth.

PubMed

Son, H K; Sivakumar, S; Rood, M J; Kim, B J

2016-01-15

Adsorption is an effective means to selectively remove volatile organic compounds (VOCs) from industrial gas streams and is particularly of use for gas streams that exhibit highly variable daily concentrations of VOCs. Adsorption of such gas streams by activated carbon fiber cloths (ACFCs) and subsequent controlled desorption can provide gas streams of well-defined concentration that can then be more efficiently treated by biofiltration than streams exhibiting large variability in concentration. In this study, we passed VOC-containing gas through an ACFC vessel for adsorption and then desorption in a concentration-controlled manner via electrothermal heating. Set-point concentrations (40-900 ppm(v)) and superficial gas velocity (6.3-9.9 m/s) were controlled by a data acquisition and control system. The results of the average VOC desorption, desorption factor and VOC in-and-out ratio were calculated and compared for various gas set-point concentrations and superficial gas velocities. Our results reveal that desorption is strongly dependent on the set-point concentration and that the VOC desorption rate can be successfully equalized and controlled via an electrothermal adsorption system. Copyright © 2015 Elsevier B.V. All rights reserved.

Seasonal patterns in nutrients, carbon, and algal responses in wadeable streams within three geographically distinct areas of the United States, 2007-08

USGS Publications Warehouse

Lee, Kathy E.; Lorenz, David L.; Petersen, James C.; Greene, John B.

2012-01-01

The U.S. Geological Survey determined seasonal variability in nutrients, carbon, and algal biomass in 22 wadeable streams over a 1-year period during 2007 or 2008 within three geographically distinct areas in the United States. The three areas are the Upper Mississippi River Basin (UMIS) in Minnesota, the Ozark Plateaus (ORZK) in southern Missouri and northern Arkansas, and the Upper Snake River Basin (USNK) in southern Idaho. Seasonal patterns in some constituent concentrations and algal responses were distinct. Nitrate concentrations were greatest during the winter in all study areas potentially because of a reduction in denitrification rates and algal uptake during the winter, along with reduced surface runoff. Decreases in nitrate concentrations during the spring and summer at most stream sites coincided with increased streamflow during the snowmelt runoff or spring storms indicating dilution. The continued decrease in nitrate concentrations during summer potentially is because of a reduction in nitrate inputs (from decreased surface runoff) or increases in biological uptake. In contrast to nitrate concentrations, ammonia concentrations varied among study areas. Ammonia concentration trends were similar at UMIS and USNK sampling sites with winter peak concentrations and rapid decreases in ammonia concentrations by spring or early summer. In contrast, ammonia concentrations at OZRK sampling sites were more variable with peak concentrations later in the year. Ammonia may accumulate in stream water in the winter under ice and snow cover at the UMIS and USNK sites because of limited algal metabolism and increased mineralization of decaying organic matter under reducing conditions within stream bottom sediments. Phosphorus concentration patterns and the type of phosphorus present changes with changing hydrologic conditions and seasons and varied among study areas. Orthophosphate concentrations tended to be greater in the summer at UMIS sites, whereas total phosphorus concentrations at most UMIS and USNK sites peaked in the spring during runoff and then decreased through the remainder of the sampling period. Total phosphorus and orthophosphate concentrations in OZRK streams peaked during summer indicating a runoff-based source of both nutrients. Orthophosphate concentrations may increase in streams in the late summer when surface runoff composes less of total streamflow, and when groundwater containing orthophosphate becomes a more dominant source in streams during lower flows. Seston chlorophyll a concentrations were greatest early in the growing season (spring), whereas the spring runoff events coincided with reductions in benthic algal chlorophyll a biomass likely because of scour of benthic algae from the channel bottom that are entrained in the water column during that period. Nitrate, ammonia, and orthophosphate concentrations also decreased during that same period, indicating dilution in the spring during runoff events. The data from this study indicate that the source of water (surface runoff or groundwater) to a stream and the intensity of major runoff events are important factors controlling instream concentrations. Biological processes appear to affect nutrient concentrations during more stable lower flow periods in later summer, fall, and winter when residence time of water in a channel is longer, which allows more time for biological uptake and transformations. Management of nutrient conditions in streams is challenging and requires an understanding of multiple factors that affect in-stream nutrient concentrations and biological uptake and growth.

Temperature and substrate chemistry as major drivers of interregional variability of leaf microbial decomposition and cellulolytic activity in headwater streams.

PubMed

Fenoy, Encarnación; Casas, J Jesús; Díaz-López, Manuel; Rubio, Juan; Guil-Guerrero, J Luís; Moyano-López, Francisco J

2016-11-01

Abiotic factors, substrate chemistry and decomposers community composition are primary drivers of leaf litter decomposition. In soil, much of the variation in litter decomposition is explained by climate and substrate chemistry, but with a significant contribution of the specialisation of decomposer communities to degrade specific substrates (home-field advantage, HFA). In streams, however, HFA effects on litter decomposition have not been explicitly tested. We evaluated responses of microbial decomposition and β-glucosidase activity to abiotic factors, substrate and decomposer assemblages, using a reciprocal litter transplant experiment: 'ecosystem type' (mountain vs lowland streams) × 'litter chemistry' (alder vs reed). Temperature, pH and ionic concentration were higher in lowland streams. Decomposition for both species was faster in lowland streams. Decomposition of reed was more accelerated in lowland compared with mountain streams than that of alder, suggesting higher temperature sensitivity of decomposition in reed. Q10 (5°C-15°C) values of β-glucosidase activity were over 2. The alkaline pH and high ionic concentration of lowland streams depleted enzyme activity. We found similar relationships of decomposition or enzyme activity with abiotic factors for both species, suggesting limited support to the HFA hypothesis. Overall, our results suggest a prime role of temperature interacting with substrate chemistry on litter decomposition. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents. 1. Hematological and population level assessment.

PubMed

Lohner, T W; Reash, R J; Willet, V E; Rose, L A

2001-11-01

Sunfish were collected from coal ash effluent-receiving streams and Ohio River watershed reference sites to assess the effects of exposure to low-level selenium concentrations. Selenium, copper, and arsenic concentrations were statistically higher in tissue samples from exposed fish than in reference fish. Leukopenia, lymphocytosis, and neutropenia were evident in exposed fish and were indicative of metal exposure and effect. White blood cell counts and percent lymphocyte values were significantly correlated with liver selenium concentrations. Plasma protein levels were significantly lower in exposed fish than in fish from the Ohio River, indicating that exposed fish may have been nutritionally stressed. Condition factors for fish from the ash pond-receiving streams were the same as, or lower than, those of fish from the reference sites. There was no evidence that the growth rate of fish in the receiving streams differed from that of fish in the reference streams. Despite liver selenium concentrations which exceeded reported toxicity thresholds and evidence of significant hematological changes, there were no significant differences in fish condition factors, liver-somatic indices, or length-weight regressions related to selenium.

Effect of deforestation on stream water chemistry in the Skrzyczne massif (the Beskid Śląski Mountains in southern Poland).

PubMed

Kosmowska, Amanda; Żelazny, Mirosław; Małek, Stanisław; Siwek, Joanna Paulina; Jelonkiewicz, Łukasz

2016-10-15

The purpose of the study was to identify the factors affecting stream water chemistry in the small mountain catchments deforested to varying degrees, from 98.7 to 14.1%, due to long-term acid deposition. Water samples were collected monthly in 2013 and 2014 from 17 streams flowing across three distinct elevation zones in the Skrzyczne massif (Poland): Upper, Middle and Lower Forest Zone. Chemical and physical analyses, including the pH, electrical conductivity (EC), total mineral content (Mt), water temperature, and the concentrations of Ca(2+), Mg(2+), Na(+), K(+), HCO3(-), SO4(2-), Cl(-), and NO3(-), were conducted. Based on Principal Component Analysis (PCA), the most important factor affecting water chemistry was human impact associated with changes in pH, SO4(2-) concentration, and the concentration of most of the main ions. The substantial acidity of the studied environment contributed to the exclusion of natural factors, associated with changes in discharge, from the list of major factors revealed by PCA. All of the streams were characterized by very low EC, Mt, and low concentrations of the main ions such as Ca(2+) and HCO3(-). This is the effect of continuous leaching of solutes from the soils by acidic precipitation. The lowest parameter values were measured for the streams situated in the Upper Forest Zone, which is associated with greater acid deposition at the higher elevations. In the streams located in the Upper Forest Zone, a higher percentage of SO4(2-) occurred than in the streams situated in the Middle and Lower Forest Zones. However, the largest share of SO4(2-) was measured in the most deforested catchment. The saturation of the studied deforested catchment with sulfur compounds is reflected by a positive correlation between SO4(2-) and discharge. Hence, a forest acts as a natural buffer that limits the level of acidity in the natural environment caused by acidic atmospheric deposition. Copyright © 2016 Elsevier B.V. All rights reserved.

Bioaccumulation syndrome: identifying factors that make some stream food webs prone to elevated mercury bioaccumulation

PubMed Central

Ward, Darren M.; Nislow, Keith H.; Folt, Carol L.

2010-01-01

Mercury is a ubiquitous contaminant in aquatic ecosystems, posing a significant health risk to humans and wildlife that eat fish. Mercury accumulates in aquatic food webs as methylmercury (MeHg), a particularly toxic and persistent organic mercury compound. While mercury in the environment originates largely from anthropogenic activities, MeHg accumulation in freshwater aquatic food webs is not a simple function of local or regional mercury pollution inputs. Studies show that even sites with similar mercury inputs can produce fish with mercury concentrations ranging over an order of magnitude. While much of the foundational work to identify the drivers of variation in mercury accumulation has focused on freshwater lakes, mercury contamination in stream ecosystems is emerging as an important research area. Here, we review recent research on mercury accumulation in stream-dwelling organisms. Taking a hierarchical approach, we identify a suite of characteristics of individual consumers, food webs, streams, watersheds, and regions that are consistently associated with elevated MeHg concentrations in stream fish. We delineate a conceptual, mechanistic basis for explaining the ecological processes that underlie this vulnerability to MeHg. Key factors, including suppressed individual growth of consumers, low rates of primary and secondary production, hydrologic connection to methylation sites (e.g. wetlands), heavily forested catchments, and acidification are frequently associated with increased MeHg concentrations in fish across both streams and lakes. Hence, we propose that these interacting factors define a syndrome of characteristics that drive high MeHg production and bioaccumulation rates across these freshwater aquatic ecosystems. Finally, based on an understanding of the ecological drivers of MeHg accumulation, we identify situations when anthropogenic effects and management practices could significantly exacerbate or ameliorate MeHg accumulation in stream fish. PMID:20536817

Quality of streams in Johnson County, Kansas, 2002--10

USGS Publications Warehouse

Rasmussen, Teresa J.; Stone, Mandy S.; Poulton, Barry C.; Graham, Jennifer L.

2012-01-01

Stream quality in Johnson County, northeastern Kansas, was assessed on the basis of land use, hydrology, stream-water and streambed-sediment chemistry, riparian and in-stream habitat, and periphyton and macroinvertebrate community data collected from 22 sites during 2002 through 2010. Stream conditions at the end of the study period are evaluated and compared to previous years, stream biological communities and physical and chemical conditions are characterized, streams are described relative to Kansas Department of Health and Environment impairment categories and water-quality standards, and environmental factors that most strongly correlate with biological stream quality are evaluated. The information is useful for improving water-quality management programs, documenting changing conditions with time, and evaluating compliance with water-quality standards, total maximum daily loads (TMDLs), National Pollutant Discharge Elimination System (NPDES) permit conditions, and other established guidelines and goals. Constituent concentrations in water during base flow varied across the study area and 2010 conditions were not markedly different from those measured in 2003, 2004, and 2007. Generally the highest specific conductance and concentrations of dissolved solids and major ions in water occurred at urban sites except the upstream Cedar Creek site, which is rural and has a large area of commercial and industrial land less than 1 mile upstream on both sides of the creek. The highest base-flow nutrient concentrations in water occurred downstream from wastewater treatment facilities. Water chemistry data represent base-flow conditions only, and do not show the variability in concentrations that occurs during stormwater runoff. Constituent concentrations in streambed sediment also varied across the study area and some notable changes occurred from previously collected data. High organic carbon and nutrient concentrations at the rural Big Bull Creek site in 2003 decreased to at least one-fourth of those concentrations in 2007 and 2010 likely because of the reduction in upstream wastewater discharge contributions. The highest concentrations of trace metals in 2010 occurred at urban sites on Mill and Indian Creeks. Zinc was the only metal to exceed the probable effects concentration in 2010, which occurred at a site on Indian Creek. In 2007, chromium and nickel at the upstream urban Cedar Creek site exceeded the probable effects concentrations, and in 2003, no metals exceeded the probable effects concentrations. Of 72 organic compounds analyzed in streambed sediment, 26 were detected including pesticides, polycyclic aromatic hydrocarbons (PAHs), fuel products, fragrances, preservatives, plasticizers, manufacturing byproducts, flame retardants, and disinfectants. All 6 PAH compounds analyzed were detected, and the probable effects concentrations for 4 of the 6 PAH compounds analyzed were exceeded in 2010. Only five pesticide compounds were detected in streambed sediment, including carbazole and four pyrethroid compounds. Chronic toxicity guidelines for pyrethroid compounds were exceeded at five sites. Biological conditions reflected a gradient in urban land use, with the less disturbed streams located in rural areas of Johnson County. About 19 percent of sites in 2010 (four sites) were fully supporting of aquatic life on the basis of the four metrics used by Kansas Department of Health and Environment to categorize sites. This is a notable difference compared to previous years when no sites (in 2003 and 2004) or just one site (in 2007) was fully supporting of aquatic life. Multimetric macroinvertebrate scores improved at the Big Bull Creek site where wastewater discharges were reduced in 2007. Environmental variables that consistently were highly negatively correlated with biological conditions were percent impervious surface and percent urban land use. In addition, density of stormwater outfall points adjacent to streams was significantly negatively correlated with biological conditions. Specific conductance of water and sum of PAH concentrations in streambed sediment also were significantly negatively correlated with biological conditions. Total nitrogen in water and total phosphorus in streambed sediment were correlated with most of the invertebrate variables, which is a notable difference from previous analyses using smaller datasets, in which nutrient relations were weak or not detected. The most important habitat variables were sinuosity, length and continuity of natural buffers, riffle substrate embeddedness, and substrate cover diversity, each of which was correlated with all invertebrate metrics including a 10-metric combined score. Correlation analysis indicated that if riparian and in-stream habitat conditions improve then so might invertebrate communities and stream biological quality. Sixty-two percent of the variance in macroinvertebrate community metrics was explained by the single environmental factor, percent impervious surface. Invertebrate responses to urbanization in Johnson County indicated linearity rather than identifiable thresholds. Multiple linear regression models developed for each of the four macroinvertebrate metrics used to determine aquatic-life-support status indicated that percent impervious surface, as a measure of urban land use, explained 34 to 67 percent of the variability in biological communities. Results indicate that although multiple factors are correlated with stream quality degradation, general urbanization, as indicated by impervious surface area or urban land use, consistently is determined to be the fundamental factor causing change in stream quality. Effects of urbanization on Johnson County streams are similar to effects described in national studies that assess effects of urbanization on stream health. Individually important environmental factors such as specific conductance of water, PAHs in streambed sediment, and stream buffer conditions, are affected by urbanization and, collectively, all contribute to stream impairments. Policies and management practices that may be most important in protecting the health of streams in Johnson County are those minimizing the effects of impervious surface, protecting stream corridors, and decreasing the loads of sediment, nutrients, and toxic chemicals that directly enter streams through stormwater runoff and discharges.

Optimizing Stream Water Mercury Sampling for Calculation of Fish Bioaccumulation Factors

EPA Science Inventory

Mercury (Hg) bioaccumulation factors (BAFs) for game fishes are widely employed for monitoring, assessment, and regulatory purposes. Mercury BAFs are calculated as the fish Hg concentration (Hgfish) divided by the water Hg concentration (Hgwater) and, consequently, are sensitive ...

Recent (2008-10) water quality in the Barton Springs segment of the Edwards aquifer and its contributing zone, central Texas, with emphasis on factors affecting nutrients and bacteria

USGS Publications Warehouse

Mahler, Barbara J.; Musgrove, MaryLynn; Sample, Thomas L.; Wong, Corinne I.

2011-01-01

The Barton Springs zone, which comprises the Barton Springs segment of the Edwards aquifer and the watersheds to the west that contribute to its recharge, is in south-central Texas, an area with rapid growth in population and increasing amounts of land area affected by development. During November 2008-March 2010, an investigation of factors affecting the fate and transport of nutrients and bacteria in the Barton Springs zone was conducted by the U.S. Geological Survey (USGS), in cooperation with the Texas Commission on Environmental Quality. The primary objectives of the study were to characterize occurrence of nutrients and bacteria in the Barton Springs zone under a range of flow conditions; to improve understanding of the interaction between surface-water quality and groundwater quality; and to evaluate how factors such as streamflow variability and dilution affect the fate and transport of nutrients and bacteria in the Barton Springs zone. The USGS collected and analyzed water samples from five streams (Barton, Williamson, Slaughter, Bear, and Onion Creeks), two groundwater wells (Marbridge and Buda), and the main orifice of Barton Springs in Austin, Texas. During the period of the study, during which the hydrologic conditions transitioned from exceptional drought to wetter than normal, water samples were collected routinely (every 3 to 4 weeks) from the streams, wells, and spring and, in response to storms, from the streams and spring. All samples were analyzed for major ions, nutrients, the bacterium Escherichia coli, and suspended sediment. During the dry period, the geochemistry of groundwater at the two wells and at Barton Springs was dominated by flow from the aquifer matrix and was relatively similar and unchanging at the three sites. At the onset of the wet period, when the streams began to flow, the geochemistry of groundwater samples from the Marbridge well and Barton Springs changed rapidly, and concentrations of most major ions and nutrients and densities of Escherichia coli became more similar to those of samples from the streams relative to concentrations and densities during the dry period. Geochemical modeling indicated that the proportion of Barton Springs discharge composed of stream recharge increased from about 0-8 percent during the dry period to about 80 percent during the wet period. The transition from exceptional drought to wetter-than-normal conditions resulted in a number of marked changes that highlight factors affecting the fate and transport of nutrients and bacteria and the strong influence of stream recharge on water quality in the Barton Springs segment of the Edwards aquifer and had a pronounced effect on the fate of nitrogen species. Organic nitrogen loaded to and stored in soils during the dry period was nitrified to nitrate when the soils were rewetted, resulting in elevated concentrations of nitrate plus nitrite in streams as these constituents were progressively leached during continued wet weather. Estimated mean monthly loads of organic nitrogen and nitrate plus nitrite in stream recharge and Barton Springs discharge, which were relatively low and constant during the dry period, increased during the wet period. Loads of organic nitrogen, on average, were about six times greater in stream recharge than in Barton Springs discharge, indicating that organic nitrogen likely was being converted to nitrate within the aquifer. Loads of total nitrogen (organic nitrogen plus ammonia and nitrate plus nitrite) in stream recharge (162 kilograms per day) and in Barton Springs discharge (157 kilograms per day) for the period of the investigation were not significantly different. Dilution was not an important factor affecting concentrations of nitrate plus nitrite in the streams or in Barton Springs during the period of this investigation: Concentrations of nitrate plus nitrite did not decrease in streams with increasing stream discharge, and nitrate plus nitrite concentrations measured at Barton

Identifying relationships between baseflow geochemistry and land use with synoptic sampling and R-Mode factor analysis

USGS Publications Warehouse

Wayland, Karen G.; Long, David T.; Hyndman, David W.; Pijanowski, Bryan C.; Woodhams, Sarah M.; Haak, Sheridan K.

2003-01-01

The relationship between land use and stream chemistry is often explored through synoptic sampling rivers at baseflow condition. However, base flow chemistry is likely to vary temporally and spatially with land use. The purpose of our study is to examine the usefulness of the synoptic sampling approach for identifying the relationship between complex land use configurations and stream water quality. This study compares biogeochemical data from three synoptic sampling events representing the temporal variability of baseflow chemistry and land use using R-mode factor analysis. Separate R-mode factor analyses of the data from individual sampling events yielded only two consistent factors. Agricultural activity was associated with elevated levels of Ca2+, Mg2+, alkalinity, and frequently K+, SO42-, and NO3-. Urban areas were associated with higher concentrations of Na+, K+, and Cl-. Other retained factors were not  consistent among sampling events, and some factors were difficult to interpret in the context of biogeochemical sources and processes. When all data were combined, further associations were revealed such as an inverse relationship between the proportion of wetlands and stream nitrate concentrations. We also found that barren lands were associated with elevated sulfate levels. This research suggests that an individual sampling event is unlikely to characterize adequately the complex processes controlling interactions between land uses and stream chemistry. Combining data collected over two years during three synoptic sampling events appears to enhance our ability to understand processes linking stream chemistry and land use.  

Composition of water and suspended sediment in streams of urbanized subtropical watersheds in Hawaii

USGS Publications Warehouse

De Carlo, E. H.; Beltran, V.L.; Tomlinson, M.S.

2004-01-01

Urbanization on the small subtropical island of Oahu, Hawaii provides an opportunity to examine how anthropogenic activity affects the composition of material transferred from land to ocean by streams. This paper investigates the variability in concentrations of trace elements (Pb, Zn, Cu, Ba, Co, As, Ni, V and Cr) in streams of watersheds on Oahu, Hawaii. The focus is on water and suspended particulate matter collected from the Ala Wai Canal watershed in Honolulu and also the Kaneohe Stream watershed. As predicted, suspended particulate matter controls most trace element transport. Elements such as Pb, Zn, Cu, Ba and Co exhibit increased concentrations within urbanized portions of the watersheds. Particulate concentrations of these elements vary temporally during storms owing to input of road runoff containing elevated concentrations of elements associated with vehicular traffic and other anthropogenic activities. Enrichments of As in samples from predominantly conservation areas are interpreted as reflecting agricultural use of fertilizers at the boundaries of urban and conservation lands. Particulate Ni, V and Cr exhibit distributions during storm events that suggest a mineralogical control. Principal component analysis of particulate trace element concentrations establishes eigenvalues that account for nearly 80% of the total variance and separates trace elements into 3 factors. Factor 1 includes Pb, Zn, Cu, Ba and Co, interpreted to represent metals with an urban anthropogenic enrichment. Factor 2 includes Ni, V and Cr, elements whose concentrations do not appear to derive from anthropogenic activity and is interpreted to reflect mineralogical control. Another, albeit less significant, anthropogenic factor includes As, Cd and U and is thought to represent agricultural inputs. Samples collected during a storm derived from an offshore low-pressure system suggest that downstream transport of upper watershed material during tradewind-derived rains results in a 2-3-fold dilution of the particulate concentrations of Pb, Zn and Cu in the Ala Wai canal watershed. ?? 2004 Elsevier Ltd. All rights reserved.

Effects of low concentrations of glyphosate-based herbicide factor 540® on an agricultural stream freshwater phytoplankton community.

PubMed

Smedbol, Élise; Gomes, Marcelo Pedrosa; Paquet, Serge; Labrecque, Michel; Lepage, Laurent; Lucotte, Marc; Juneau, Philippe

2018-02-01

Residual glyphosate from glyphosate based herbicides (GBH) are ubiquitously detected in streams draining agricultural fields, and may affect phytoplankton communities present in these ecosystems. Here, the effects of the exposure (96 h) of a phytoplankton community collected in an agricultural stream to various glyphosate concentrations (1, 5, 10, 50, 100, 500 and 1000 μg l -1 ) of Factor 540 ® GBH were investigated. The lowest GBH concentration of 1 μg l -1 reduced chlorophyll a and carotenoid contents. Low glyphosate concentrations, such as 5 and 10 μg l -1 , promoted changes in the community's structure and reduced the diversity of the main algal species. At glyphosate concentrations ranging from 50 to 1000 μg l -1 , the phytoplankton community's composition was modified and new main species appeared. The highest glyphosate concentrations (500 and 1000 μg l -1 ) affected the shikimate content, the lipid peroxidation and the activity of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase). These results indicate that GBH can modify structural and functional properties of freshwater phytoplankton communities living in streams located in agricultural areas at glyphosate concentrations much inferior to the 800 μg l -1 threshold set by the Canadian guidelines for the protection of aquatic life. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Concentration-discharge relationships in headwater streams of the Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Hunsaker, Carolyn T.; Johnson, Dale W.

2017-09-01

We examined stream water concentration-discharge relationships for eight small, forest watersheds ranging in elevation from 1485 to 2465 m in the southern Sierra Nevada. These headwater streams revealed nearly chemostatic behavior by current definitions for K+, Ca2+, Mg2+, Na+, Cl-, and SO42- in most cases but not for NH4+, NO3-, or ortho-P. The latter ions were somewhat enriched during high flows. All ions studied showed a dilution process at lower flows (<50 L s-1) with the concentration-discharge relationship being more chemostatic at higher flows. While previous studies in the Sierra Nevada have reported peak concentrations of NH4+, NO3-, and SO42- during snowmelt, the headwater systems of the Kings River Experimental Watersheds experience peak concentrations of these ions during the fall rains after the dry summer. These forested watersheds span the rain-snow transition zone, are 49-228 ha in size, and have soils derived from granite. A statistically significant relationship between soils and stream water concentrations for ortho-P, Ca2+, and Na+ strongly suggests that soil chemistry has a major influence on stream water chemistry. Factors controlling stream water NH4+, NO3-, and SO42- concentrations are less clear, but one possible source of spikes in these ions during storm events is input from O-horizon runoff where high concentrations were measured. Overall, stream water concentration-discharge relationships for these Sierran watersheds are similar to those found in other watershed systems (nearly chemostatic); however, the dominant processes controlling these relationships are probably localized because of different watershed characteristics like soil chemistry, vegetation cover, hydrologic flow paths, and weather patterns.

Seasonal changes in the diurnal in-stream nitrate concentration oscillations

NASA Astrophysics Data System (ADS)

Rusjan, S.; Mikoš, M.

2009-04-01

A variability of seasonal changes in the diurnal in-stream NO3-N concentration oscillations was studied through high-frequency measurements of the stream-water's physical, chemical parameters (in-stream NO3-N concentration, water temperature, dissolved oxygen, pH) and hydrometeorological variables (stream discharge, solar radiation) under hydrologically stable conditions. The study was carried out in 2006, within the 42 km2 forested Padež stream watershed in the southwestern part of Slovenia, which is characterized by distinctive hydrogeological settings (flysch) and climate conditions (transitional area between the Mediterranean and continental climate). Fine temporal resolution of the data measured at 15 minute intervals enabled the identification of the main driving factors responsible for the seasonal variability in the diurnal pattern of the streamwater NO3-N concentrations vs. seasonal and diurnal behavior of meteorological and other water chemistry constituents. Seasonal variability of the shifts in daily maximum (up to 6 hours) and minimum NO3-N concentrations (between 1 and 3 hours) and changes in the amplitude of the daily NO3-N concentration oscillations (in order of 0.1-0.3 mg/l-N) offer supplementary evidence of the in-stream NO3-N processing by photoautotrophs. A wavelet analysis was further used to acquire clear, de-noised NO3-N concentration signals on which models in the form of Fourier series were build, reaching R2 values between 0.73 and 0.94. The models can be used to simulate the in-stream NO3-N oscillating signal in order to obtain more accurate assessment of the NO3-N exports from the forested watershed in different seasonal settings, undisturbed by the changing hydrological conditions.

Seasonal Changes in diurnal in-Stream Nitrate Concentration Oscillations

NASA Astrophysics Data System (ADS)

Rusjan, Simon; Mikoš, Matjaž; Mitja, Brilly; Vidmar, Andrej

2010-05-01

A variability of seasonal changes in the diurnal in-stream NO3-N concentration oscillations was studied through high-frequency measurements of the stream-water's physical, chemical parameters (in-stream NO3-N concentration, water temperature, dissolved oxygen, pH) and hydrometeorological variables (stream discharge, solar radiation) under hydrologically stable conditions. The study was carried out in 2006, within the 42 km2 forested Padež stream watershed in the southwestern part of Slovenia, which is characterized by distinctive hydrogeological settings (flysch) and climate conditions (transitional area between the Mediterranean and continental climate). Fine temporal resolution of the data measured at 15 minute intervals enabled the identification of the main driving factors responsible for the seasonal variability in the diurnal pattern of the streamwater NO3-N concentrations vs. seasonal and diurnal behavior of meteorological and other water chemistry constituents. Seasonal variability of the shifts in daily maximum (up to 6 hours) and minimum NO3-N concentrations (between 1 and 3 hours) and changes in the amplitude of the daily NO3-N concentration oscillations (in order of 0.1-0.3 mg/l-N) offer supplementary evidence of the in-stream NO3-N processing by photoautotrophs. A wavelet analysis was further used to acquire clear, de-noised NO3-N concentration signals on which models in the form of Fourier series were build, reaching R2 values between 0.73 and 0.94. The models can be used to simulate the in-stream NO3-N oscillating signal in order to obtain more accurate assessment of the NO3-N exports from the forested watershed in different seasonal settings, undisturbed by the changing hydrological conditions.

Coniferous coverage as well as catchment steepness influences local stream nitrate concentrations within a nitrogen-saturated forest in central Japan.

PubMed

Watanabe, Mirai; Miura, Shingo; Hasegawa, Shun; Koshikawa, Masami K; Takamatsu, Takejiro; Kohzu, Ayato; Imai, Akio; Hayashi, Seiji

2018-04-28

High concentrations of nitrate have been detected in streams flowing from nitrogen-saturated forests; however, the spatial variations of nitrate leaching within those forests and its causes remain poorly explored. The aim of this study is to evaluate the influences of catchment topography and coniferous coverage on stream nitrate concentrations in a nitrogen-saturated forest. We measured nitrate concentrations in the baseflow of headwater streams at 40 montane forest catchments on Mount Tsukuba in central Japan, at three-month intervals for 1 year, and investigated their relationship with catchment topography and with coniferous coverage. Although stream nitrate concentrations varied from 0.5 to 3.0 mgN L -1 , those in 31 catchments consistently exceeded 1 mgN L -1 , indicating that this forest had experienced nitrogen saturation. A classification and regression tree analysis with multiple environmental factors showed that the mean slope gradient and coniferous coverage were the best and second best, respectively, at explaining inter-catchment variance of stream nitrate concentrations. This analysis suggested that the catchments with steep topography and high coniferous coverage tend to have high nitrate concentrations. Moreover, in the three-year observation period for five adjacent catchments, the two catchments with relatively higher coniferous coverage consistently had higher stream nitrate concentrations. Thus, the spatial variations in stream nitrate concentrations were primarily regulated by catchment steepness and, to a lesser extent, coniferous coverage in this nitrogen-saturated forest. Our results suggest that a decrease in coniferous coverage could potentially contribute to a reduction in nitrate leaching from this nitrogen-saturated forest, and consequently reduce the risk of nitrogen overload for the downstream ecosystems. This information will allow land managers and researchers to develop improved management plans for this and similar forests in Japan and elsewhere. Copyright © 2018 Elsevier B.V. All rights reserved.

Coupled hydrological and biogeochemical processes controlling variability of nitrogen species in streamflow during autumn in an upland forest

USGS Publications Warehouse

Sebestyen, Stephen D.; Shanley, James B.; Boyer, Elizabeth W.; Kendall, Carol; Doctor, Daniel H.

2014-01-01

Autumn is a season of dynamic change in forest streams of the northeastern United States due to effects of leaf fall on both hydrology and biogeochemistry. Few studies have explored how interactions of biogeochemical transformations, various nitrogen sources, and catchment flow paths affect stream nitrogen variation during autumn. To provide more information on this critical period, we studied (1) the timing, duration, and magnitude of changes to stream nitrate, dissolved organic nitrogen (DON), and ammonium concentrations; (2) changes in nitrate sources and cycling; and (3) source areas of the landscape that most influence stream nitrogen. We collected samples at higher temporal resolution for a longer duration than typical studies of stream nitrogen during autumn. This sampling scheme encompassed the patterns and extremes that occurred during base flow and stormflow events of autumn. Base flow nitrate concentrations decreased by an order of magnitude from 5.4 to 0.7 µmol L−1 during the week when most leaves fell from deciduous trees. Changes to rates of biogeochemical transformations during autumn base flow explained the low nitrate concentrations; in-stream transformations retained up to 72% of the nitrate that entered a stream reach. A decrease of in-stream nitrification coupled with heterotrophic nitrate cycling were primary factors in the seasonal nitrate decline. The period of low nitrate concentrations ended with a storm event in which stream nitrate concentrations increased by 25-fold. In the ensuing weeks, peak stormflow nitrate concentrations progressively decreased over closely spaced, yet similarly sized events. Most stormflow nitrate originated from nitrification in near-stream areas with occasional, large inputs of unprocessed atmospheric nitrate, which has rarely been reported for nonsnowmelt events. A maximum input of 33% unprocessed atmospheric nitrate to the stream occurred during one event. Large inputs of unprocessed atmospheric nitrate show direct and rapid effects on forest streams that may be widespread, although undocumented, throughout nitrogen-polluted temperate forests. In contrast to a week-long nitrate decline during peak autumn litterfall, base flow DON concentrations increased after leaf fall and remained high for 2 months. Dissolved organic nitrogen was hydrologically flushed to the stream from riparian soils during stormflow. In contrast to distinct seasonal changes in base flow nitrate and DON concentrations, ammonium concentrations were typically at or below the detection limit, similar to the rest of the year. Our findings reveal couplings among catchment flow paths, nutrient sources, and transformations that control seasonal extremes of stream nitrogen in forested landscapes.

Watershed Regressions for Pesticides (WARP) models for predicting stream concentrations of multiple pesticides

USGS Publications Warehouse

Stone, Wesley W.; Crawford, Charles G.; Gilliom, Robert J.

2013-01-01

Watershed Regressions for Pesticides for multiple pesticides (WARP-MP) are statistical models developed to predict concentration statistics for a wide range of pesticides in unmonitored streams. The WARP-MP models use the national atrazine WARP models in conjunction with an adjustment factor for each additional pesticide. The WARP-MP models perform best for pesticides with application timing and methods similar to those used with atrazine. For other pesticides, WARP-MP models tend to overpredict concentration statistics for the model development sites. For WARP and WARP-MP, the less-than-ideal sampling frequency for the model development sites leads to underestimation of the shorter-duration concentration; hence, the WARP models tend to underpredict 4- and 21-d maximum moving-average concentrations, with median errors ranging from 9 to 38% As a result of this sampling bias, pesticides that performed well with the model development sites are expected to have predictions that are biased low for these shorter-duration concentration statistics. The overprediction by WARP-MP apparent for some of the pesticides is variably offset by underestimation of the model development concentration statistics. Of the 112 pesticides used in the WARP-MP application to stream segments nationwide, 25 were predicted to have concentration statistics with a 50% or greater probability of exceeding one or more aquatic life benchmarks in one or more stream segments. Geographically, many of the modeled streams in the Corn Belt Region were predicted to have one or more pesticides that exceeded an aquatic life benchmark during 2009, indicating the potential vulnerability of streams in this region.

Forecasting fish biomasses, densities, productions, and bioaccumulation potentials of mid-atlantic wadeable streams.

PubMed

Barber, M Craig; Rashleigh, Brenda; Cyterski, Michael J

2016-01-01

Regional fishery conditions of Mid-Atlantic wadeable streams in the eastern United States are estimated using the Bioaccumulation and Aquatic System Simulator (BASS) bioaccumulation and fish community model and data collected by the US Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP). Average annual biomasses and population densities and annual productions are estimated for 352 randomly selected streams. Realized bioaccumulation factors (BAF) and biomagnification factors (BMF), which are dependent on these forecasted biomasses, population densities, and productions, are also estimated by assuming constant water exposures to methylmercury and tetra-, penta-, hexa-, and hepta-chlorinated biphenyls. Using observed biomasses, observed densities, and estimated annual productions of total fish from 3 regions assumed to support healthy fisheries as benchmarks (eastern Tennessee and Catskill Mountain trout streams and Ozark Mountains smallmouth bass streams), 58% of the region's wadeable streams are estimated to be in marginal or poor condition (i.e., not healthy). Using simulated BAFs and EMAP Hg fish concentrations, we also estimate that approximately 24% of the game fish and subsistence fishing species that are found in streams having detectable Hg concentrations would exceed an acceptable human consumption criterion of 0.185 μg/g wet wt. Importantly, such streams have been estimated to represent 78.2% to 84.4% of the Mid-Atlantic's wadeable stream lengths. Our results demonstrate how a dynamic simulation model can support regional assessment and trends analysis for fisheries. © 2015 SETAC.

Dissolved Organic Carbon in Headwater Streams and Riparian Soil Organic Carbon along an Altitudinal Gradient in the Wuyi Mountains, China

PubMed Central

Huang, Wei; McDowell, William H.; Zou, Xiaoming; Ruan, Honghua; Wang, Jiashe; Li, Liguang

2013-01-01

Stream water dissolved organic carbon (DOC) correlates positively with soil organic carbon (SOC) in many biomes. Does this relationship hold in a small geographic region when variations of temperature, precipitation and vegetation are driven by a significant altitudinal gradient? We examined the spatial connectivity between concentrations of DOC in headwater stream and contents of riparian SOC and water-soluble soil organic carbon (WSOC), riparian soil C:N ratio, and temperature in four vegetation types along an altitudinal gradient in the Wuyi Mountains, China. Our analyses showed that annual mean concentrations of headwater stream DOC were lower in alpine meadow (AM) than in subtropical evergreen broadleaf forest (EBF), coniferous forest (CF), and subalpine dwarf forest (SDF). Headwater stream DOC concentrations were negatively correlated with riparian SOC as well as WSOC contents, and were unrelated to riparian soil C:N ratio. Our findings suggest that DOC concentrations in headwater streams are affected by different factors at regional and local scales. The dilution effect of higher precipitation and adsorption of soil DOC to higher soil clay plus silt content at higher elevation may play an important role in causing lower DOC concentrations in AM stream of the Wuyi Mountains. Our results suggest that upscaling and downscaling of the drivers of DOC export from forested watersheds when exploring the response of carbon flux to climatic change or other drivers must done with caution. PMID:24265737

Factors affecting low summer dissolved oxygen concentrations in Mississippi Delta bayous

USDA-ARS?s Scientific Manuscript database

Streams in watersheds supporting intensive row-crop agriculture are vulnerable to ecological degradation due to non-point source pollutants such as nutrients. Low gradient streams such as bayous are especially susceptible to pollutants due to increased water residence time, and they often exhibit po...

The relationship of metals, bifenthrin, physical habitat metrics, grain size, total organic carbon, dissolved oxygen and conductivity to Hyalella sp. abundance in urban California streams.

PubMed

Hall, Lenwood W; Anderson, Ronald D

2013-01-01

The objectives of this study were to determine the relationship between Hyalella sp. abundance in four urban California streams and the following parameters: (1) 8 bulk metals (As, Cd, Cr, Cu, Pb, Hg, Ni, and Zn) and their associated sediment Threshold Effect Levels (TELs); (2) bifenthrin sediment concentrations; (3) 10 habitat metrics and total score; (4) grain size (% sand, silt and clay); (5) Total Organic Carbon (TOC); (6) dissolved oxygen; and (7) conductivity. California stream data used for this study were collected from Kirker Creek (2006 and 2007), Pleasant Grove Creek (2006, 2007 and 2008), Salinas streams (2009 and 2010) and Arcade Creek (2009 and 2010). Hyalella abundance in the four California streams generally declined when metals concentrations were elevated beyond the TELs. There was also a statistically significant negative relationship between Hyalella abundance and % silt for these 4 California streams as Hyalella were generally not present in silt areas. No statistically significant relationships were reported between Hyalella abundance and metals concentrations, bifenthrin concentrations, habitat metrics, % sand, % clay, TOC, dissolved oxygen and conductivity. The results from this study highlight the complexity of assessing which factors are responsible for determining the abundance of amphipods, such as Hyalella sp., in the natural environment.

Estimated fecal coliform bacteria concentrations using near real-time continuous water-quality and streamflow data from five stream sites in Chester County, Pennsylvania, 2007–16

USGS Publications Warehouse

Senior, Lisa A.

2017-09-15

Several streams used for recreational activities, such as fishing, swimming, and boating, in Chester County, Pennsylvania, are known to have periodic elevated concentrations of fecal coliform bacteria, a type of bacteria used to indicate the potential presence of fecally related pathogens that may pose health risks to humans exposed through water contact. The availability of near real-time continuous stream discharge, turbidity, and other water-quality data for some streams in the county presents an opportunity to use surrogates to estimate near real-time concentrations of fecal coliform (FC) bacteria and thus provide some information about associated potential health risks during recreational use of streams.The U.S. Geological Survey (USGS), in cooperation with the Chester County Health Department (CCHD) and the Chester County Water Resources Authority (CCWRA), has collected discrete stream samples for analysis of FC concentrations during March–October annually at or near five gaging stations where near real-time continuous data on stream discharge, turbidity, and water temperature have been collected since 2007 (or since 2012 at 2 of the 5 stations). In 2014, the USGS, in cooperation with the CCWRA and CCHD, began to develop regression equations to estimate FC concentrations using available near real-time continuous data. Regression equations included possible explanatory variables of stream discharge, turbidity, water temperature, and seasonal factors calculated using Julian Day with base-10 logarithmic (log) transformations of selected variables.The regression equations were developed using the data from 2007 to 2015 (101–106 discrete bacteria samples per site) for three gaging stations on Brandywine Creek (West Branch Brandywine Creek at Modena, East Branch Brandywine Creek below Downingtown, and Brandywine Creek at Chadds Ford) and from 2012 to 2015 (37–38 discrete bacteria samples per site) for one station each on French Creek near Phoenixville and White Clay Creek near Strickersville. Fecal coliform bacteria data collected by USGS in 2016 (about nine samples per site) were used to validate the equations. The best-fit regression equations included log turbidity and seasonality factors computed using Julian Day as explanatory variables to estimate log FC concentrations at all five stream sites. The adjusted coefficient of determination for the equations ranged from 0.61 to 0.76, with the strength of the regression equations likely affected in part by the limited amount and variability of FC bacteria data. During summer months, the estimated and measured FC concentrations commonly were greater than the Pennsylvania Department of Environmental Protection established standards of 200 and 400 colonies per 100 milliliters for water contact from May through September at the 5 stream sites, with concentrations typically higher at 2 sites (White Clay Creek and West Branch Brandywine Creek at Modena) than at the other 3 sites. The estimated concentrations of FC bacteria during the summer months commonly were higher than measured concentrations and therefore could be considered cautious estimates of potential human-health risk. Additional water-quality data are needed to maintain and (or) improve the ability of regression equations to estimate FC concentrations by use of surrogate data.

EPA Office of Water (OW): 2002 SPARROW Total NP (Catchments)

EPA Pesticide Factsheets

SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modeling tool with output that allows the user to interpret water quality monitoring data at the regional and sub-regional scale. The model relates in-stream water-quality measurements to spatially referenced characteristics of watersheds, including pollutant sources and environmental factors that affect rates of pollutant delivery to streams from the land and aquatic, in-stream processing . The core of the model consists of a nonlinear regression equation describing the non-conservative transport of contaminants from point and non-point (or ??diffuse??) sources on land to rivers and through the stream and river network. SPARROW estimates contaminant concentrations, loads (or ??mass,?? which is the product of concentration and streamflow), and yields in streams (mass of nitrogen and of phosphorus entering a stream per acre of land). It empirically estimates the origin and fate of contaminants in streams and receiving bodies, and quantifies uncertainties in model predictions. The model predictions are illustrated through detailed maps that provide information about contaminant loadings and source contributions at multiple scales for specific stream reaches, basins, or other geographic areas.

Hydrogeologic controls on groundwater discharge and nitrogen loads in a coastal watershed

USGS Publications Warehouse

Russoniello, Chrtopher J.; Konikow, Leonard F.; Kroeger, Kevin D.; Fernandez, Cristina; Andres, A. Scott; Michael, Holly A.

2016-01-01

Submarine groundwater discharge (SGD) is a small portion of the global water budget, but a potentially large contributor to coastal nutrient budgets due to high concentrations relative to stream discharge. A numerical groundwater flow model of the Inland Bays Watershed, Delaware, USA, was developed to identify the primary hydrogeologic factors that affect groundwater discharge rates and transit times to streams and bays. The distribution of groundwater discharge between streams and bays is sensitive to the depth of the water table below land surface. Higher recharge and reduced hydraulic conductivity raised the water table and increased discharge to streams relative to bays compared to the Reference case (in which 66% of recharge is discharged to streams). Increases to either factor decreased transit times for discharge to both streams and bays compared to the Reference case (in which mean transit times are 56.5 and 94.3 years, respectively), though sensitivity to recharge is greater. Groundwater-borne nitrogen loads were calculated from nitrogen concentrations measured in discharging fresh groundwater and modeled SGD rates. These loads combined with long SGD transit times suggest groundwater-borne nitrogen reductions and estuarine water quality improvements will lag decades behind implementation of efforts to manage nutrient sources. This work enhances understanding of the hydrogeologic controls on and uncertainties in absolute and relative rates and transit times of groundwater discharge to streams and bays in coastal watersheds.

Landscape control on the hydrogeochemistry of As, Co and Pb in a boreal stream network

NASA Astrophysics Data System (ADS)

Wällstedt, Teresia; Björkvald, Louise; Laudon, Hjalmar; Borg, Hans; Mörth, Carl-Magnus

2017-08-01

In a boreal stream network, stream water concentrations of As, Co and Pb (filtered, <0.4 μm) of 10 nested streams were studied during two consecutive years in order to evaluate the influence of land cover on the temporal and spatial variability of metal concentrations and speciation. Mean concentrations of Co and Pb showed significant but contrasting relationship to landscape type, while As concentrations were not related to landscape type. Highest concentrations of Pb were found in the wetland dominated streams (>30% wetland), which was suggested to be controlled by atmospheric deposition in combination with high DOC release from the wetlands. For Co, the highest concentrations were found in the forest dominated sites (>98% forest), which were attributed to the weathering of minerogenic sources. Contrasting response to runoff events could also be related to landscape type; during the spring flood, decreasing concentrations of As, Co and Pb were observed in the wetland dominated catchments due to dilution, while increasing concentrations during spring flood were observed in the mixed catchments (2-30% wetland) and to some degree in the forested catchments, probably due to flushing of the organic-rich riparian sources. Further, metal speciation was calculated using the geochemical equilibrium model Visual MINTEQ. This suggests that dissolved inorganic species of As and Co dominated in headwater streams with low pH while DOC had a major influencing role for Pb. In the larger mixed streams where pH was higher and precipitation of e.g. colloidal Fe and Mn (hydr)oxides was favoured, the major influencing factor was instead adsorption to colloidal Fe for As and Pb, while association to organic matter and colloids of e.g. Mn influenced the concentrations of Co. We thus conclude that landscape type and the magnitude of the runoff events are of great importance for the spatial and temporal variations of As, Co and Pb in this boreal stream network. Projected climate change, with increasing runoff, may therefore influence riverine concentrations and fluxes differently, depending on the prevailing landscape type.

Contributions of Phosphorus from Groundwater to Streams in the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces, Eastern United States

USGS Publications Warehouse

Denver, Judith M.; Cravotta,, Charles A.; Ator, Scott W.; Lindsey, Bruce D.

2011-01-01

Phosphorus from natural and human sources is likely to be discharged from groundwater to streams in certain geochemical environments. Water-quality data collected from 1991 through 2007 in paired networks of groundwater and streams in different hydrogeologic and land-use settings of the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces in the eastern United States were compiled and analyzed to evaluate the sources, fate, and transport of phosphorus. The median concentrations of phosphate in groundwater from the crystalline and siliciclastic bedrock settings (0.017 and 0.020 milligrams per liter, respectively) generally were greater than the median for the carbonate setting (less than 0.01 milligrams per liter). In contrast, the median concentrations of dissolved phosphate in stream base flow from the crystalline and siliciclastic bedrock settings (0.010 and 0.014 milligrams per liter, respectively) were less than the median concentration for base-flow samples from the carbonate setting (0.020 milligrams per liter). Concentrations of phosphorus in many of the stream base-flow and groundwater samples exceeded ecological criteria for streams in the region. Mineral dissolution was identified as the dominant source of phosphorus in the groundwater and stream base flow draining crystalline or siliciclastic bedrock in the study area. Low concentrations of dissolved phosphorus in groundwater from carbonate bedrock result from the precipitation of minerals and (or) from sorption to mineral surfaces along groundwater flow paths. Phosphorus concentrations are commonly elevated in stream base flow in areas underlain by carbonate bedrock, however, presumably derived from in-stream sources or from upland anthropogenic sources and transported along short, shallow groundwater flow paths. Dissolved phosphate concentrations in groundwater were correlated positively with concentrations of silica and sodium, and negatively with alkalinity and concentrations of calcium, magnesium, chloride, nitrate, sulfate, iron, and aluminum. These associations can result from the dissolution of alkali feldspars containing phosphorus; the precipitation of apatite; the precipitation of calcite, iron hydroxide, and aluminum hydroxide with associated sorption of phosphate ions; and the potential for release of phosphate from iron-hydroxide and other iron minerals under reducing conditions. Anthropogenic sources of phosphate such as fertilizer and manure and processes such as biological uptake, evapotranspiration, and dilution also affect phosphorus concentrations. The phosphate concentrations in surface water were not correlated with the silica concentration, but were positively correlated with concentrations of major cations and anions, including chloride and nitrate, which could indicate anthropogenic sources and effects of evapotranspiration on surface-water quality. Mixing of older, mineralized groundwater with younger, less mineralized, but contaminated groundwater was identified as a critical factor affecting the quality of stream base flow. In-stream processing of nutrients by biological processes also likely increases the phosphorus concentration in surface waters. Potential geologic contributions of phosphorus to groundwater and streams may be an important watershed-management consideration in certain hydrogeologic and geochemical environments. Geochemical controls effectively limit phosphorus transport through groundwater to streams in areas underlain by carbonate rocks; however, in crystalline and siliciclastic settings, phosphorus from mineral or human sources may be effectively transported by groundwater and contribute a substantial fraction to base-flow stream loads.

Factors affecting low summer dissolved oxygen concentrations in Mississippi Delta bayous

USDA-ARS?s Scientific Manuscript database

Streams in watersheds supporting intensive row-crop agriculture are vulnerable to ecological degradation due to non-point source discharge of pollutants such as nutrients. Low gradient streams such as bayous are especially susceptible due to increased water residence time, and often result in poor w...

Source apportionment of trace metals in surface waters of a polluted stream using multivariate statistical analyses.

PubMed

Pekey, Hakan; Karakaş, Duran; Bakoğlu, Mithat

2004-11-01

Surface water samples were collected from ten previously selected sites of the polluted Dil Deresi stream, during two field surveys, December 2001 and April 2002. All samples were analyzed using ICP-AES, and the concentrations of trace metals (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Pb, Sn and Zn) were determined. The results were compared with national and international water quality guidelines, as well as literature values reported for similar rivers. Factor analysis (FA) and a factor analysis-multiple regression (FA-MR) model were used for source apportionment and estimation of contributions from identified sources to the concentration of each parameter. By a varimax rotated factor analysis, four source types were identified as the paint industry; sewage, crustal and road traffic runoff for trace metals, explaining about 83% of the total variance. FA-MR results showed that predicted concentrations were calculated with uncertainties lower than 15%.

Tritium Separation from High Volume Dilute Aqueous Streams- Milestone Report for M3FT-15OR0302092

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhave, Ramesh R.; Jubin, Robert Thomas; Spencer, Barry B.

2016-02-29

This report describes the synthesis and evaluation of molecular sieve zeolite membranes to separate and concentrate tritiated water (HTO) from dilute HTO-bearing aqueous streams. Several silico alumino phosphate (SAPO-34) molecular sieve zeolite membranes were synthesized and characterized with gas and vapor permeation measurements. The pervaporation process performance was evaluated for the separation and concentration of tritiated water. Experiments were performed over a range of tritiated water concentration covering the range of concentration anticipated in nuclear fuel processing where potentially both acid and water streams are recycled. The permeate was recovered under vacuum. The tritium concentration ranged from 0.5 to 1more » mCi/mL which is about 0.1 mg/L or 0.1 ppm. The HTO concentration was three orders of magnitude lower than experiments performed with simulated feed containing HDO (>100 ppm) using deuterated water where high separation factors (>10) were obtained using SAPO membranes. Separation factor calculated from the measured tritium concentrations ranged from 0.83-0.98. Although the membrane performance characterization results were lower than expected, they can be explained on the basis of low feed volume and three orders of magnitude lower HTO concentration compared to HDO concentration in deuterated water. We have identified several new approaches, such as tuning the diffusion coefficient of HTO, that may help achieve preferential transport of tritium (HTO) resulting in a substantially more concentrated permeate.« less

Rock-Bound Arsenic Influences Ground Water and Sediment Chemistry Throughout New England

USGS Publications Warehouse

Robinson, Gilpin R.; Ayotte, Joseph D.

2007-01-01

The information in this report was presented at the Northeastern Region Geological Society of America meeting held March 11-14, 2007, in Durham, New Hampshire. In the New England crystalline bedrock aquifer, concentrations of arsenic that exceed the drinking water standard of 10 ?g/L occur most frequently in ground water from wells sited in specific metamorphic and igneous rock units. Geochemical investigations indicate that these geologic units typically have moderately elevated whole-rock concentrations of arsenic compared to other rocks in the region. The distribution of ground water wells with As > 5 ?g/L has a strong spatial correlation with specific bedrock units where average whole-rock concentrations of arsenic exceed 1.1 mg/kg and where geologic and geochemical factors produce high pH ground water. Arsenic concentrations in stream sediments collected from small drainages reflect the regional distribution of this natural arsenic source and have a strong correlation with both rock chemistry and the distribution of bedrock units with elevated arsenic chemistry. The distribution of ground water wells with As > 5 ?g/L has a strong spatial correlation with the distribution of stream sediments where concentrations of arsenic exceed 6 mg/kg. Stream sediment chemistry also has a weak correlation with the distribution of agricultural lands where arsenical pesticides were used on apple, blueberry, and potato crops. Elevated arsenic concentrations in bedrock wells, however, do not correlate with agricultural areas where arsenical pesticides were used. These results indicate that both stream sediment chemistry and the solubility and mobility of arsenic in ground water in bedrock are influenced by host-rock arsenic concentrations. Stream sediment chemistry and the distribution of geologic units have been found to be useful parameters to predict the areas of greatest concern for elevated arsenic in ground water and to estimate the likely levels of human exposure to elevated arsenic in drinking water in New England. However, the extreme local variability of arsenic concentrations in ground water from these rock sources indicate that arsenic concentrations in ground water are affected by other factors in addition to arsenic concentrations in rock.

The cascade construction of artificial ponds as a tool for urban stream restoration - The use of benthic diatoms to assess the effects of restoration practices.

PubMed

Żelazna-Wieczorek, Joanna; Nowicka-Krawczyk, Paulina

2015-12-15

A series of cascade artificial ponds were constructed to improve the ecological status of the stream. To evaluate the effects of restoration practices, a bioassessment, based on phytobenthic algae - the diatoms, was made. Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) of diatom assemblages allowed for evaluating the influence of a series of cascade artificial ponds on stream integrity. To reveal which environmental factors had the greatest influence on shaping diatom assemblages, the BIO-ENV procedure was used, and in order to examine whether these factors had equal influence on diatoms along the stream, Redundancy Analysis (RDA) was used. The analysis of diatom assemblages allowed for the calculation of the diatom indices in order to assess the water quality and the ecological status of the stream. Artificial ponds constructed on the stream had significant effects on the integrity of the stream ecosystem. Diatom assemblages characteristic of stream habitats were disrupted by the species from ponds. HCA and PCA revealed that the stream was clearly divided into three sections: ponds, stream parts under the influence of ponds, and stream parts isolated from ponds. The ponds thus altered stream environmental conditions. Benthic diatom assemblages were affected by a combination of four environmental factors: the concentration of ammonium ions, dissolved oxygen, conductivity, and the amount of total suspended material in the water. These factors, together with water pH, had a diverse influence on diatom assemblages alongside the stream, which was caused by a series of cascade ponds. In theory, this restoration practice should restore the stream close to its natural state, but bioassessment of the stream ecosystem based on diatoms revealed that there was no improvement of the ecological status alongside the stream. The construction of artificial ponds disrupted stream continuity and altered the character of the stream ecosystem. Copyright © 2015 Elsevier B.V. All rights reserved.

Trends in hydrometeorological conditions and stream water organic carbon in boreal forested catchments.

PubMed

Sarkkola, Sakari; Koivusalo, Harri; Laurén, Ari; Kortelainen, Pirkko; Mattsson, Tuija; Palviainen, Marjo; Piirainen, Sirpa; Starr, Mike; Finér, Leena

2009-12-15

Temporal trends in stream water total organic carbon (TOC) concentration and export were studied in 8 forested headwater catchments situated in eastern Finland. The Seasonal Kendall test was conducted to identify the trends and a mixed model regression analysis was used to describe how catchment characteristics and hydrometeorological variables (e.g. precipitation, air and stream water temperatures, and atmospheric deposition) related to the variation in the concentration and export of stream water TOC. The 8 catchments varied in size from 29 to 494 ha and in the proportion of peatland they contained, from 8 to 70%. Runoff and TOC concentration were monitored for 15-29 years (1979-2006). Trends and variation in TOC levels were analysed from annual and seasonal time series. Mean annual TOC concentration increased significantly in seven of the eight catchments. The trends were the strongest in spring and most apparent during the last decade of the study period. The slopes of the trends were generally smaller than the variation in TOC concentration between years and seasons and between catchments. The annual TOC export showed no clear trends and values were largely determined by the temporal variability in runoff. Annual runoff showed a decreasing trend in two of the eight catchments. Mean annual air and stream water temperatures showed increasing trends, most clearly seen in the summer and autumn series. According to our modeling results, stream water temperature, precipitation and peatland percentage were the most important variables explaining annual and most seasonal TOC concentrations. The atmospheric deposition of SO4, NH4, and NO3 decreased significantly over the study period, but no significant link with TOC concentration was found. Precipitation was the main hydrometeorological driver of the TOC export. We concluded that stream water TOC concentrations and exports are mainly driven by catchment characteristics and hydrometeorological factors rather than trends in atmospheric acid deposition.

Atrazine concentrations in near-surface aquifers: A censored regression approach

USGS Publications Warehouse

Liu, S.; Yen, S.T.; Kolpin, D.W.

1996-01-01

In 1991, the U.S. Geological Survey (USGS) conducted a study to investigate the occurrence of atrazine (2-chloro-4-ethylamino-6- isopropylamino-s-triazine) and other agricultural chemicals in near-surface aquifers in the midcontinental USA. Because about 83% of the atrazine concentrations from the USGS study were censored, standard statistical estimation procedures could not be used. To determine factors that affect atrazine concentrations in groundwater while accommodating the high degree of data censoring. Tobit models were used (normal homoscedastic, normal heteroscedastic, lognormal homoscedastic, and lognormal heteroscedastic). Empirical results suggest that the lognormal heteroscedastic Tobit model is the model of choice for this type of study. This model determined the following factors to have the strongest effect on atrazine concentrations in groundwater: percent of pasture within 3.2 km, percent of forest within 3.2 km (2 mi), mean open interval of the well, primary water use of a well, aquifer class (unconsolidated or bedrock), aquifer type (unconfined or confined), existence of a stream within 30 m (100 ft), existence of a stream within 30 m to 0.4 km (0.25 mi), and existence of a stream within 0.4 to 3.2 km. Examining the elasticities of the continuous explanatory factors provides further insight into their effects on atrazine concentrations in groundwater. This study documents a viable statistical method that can be used to accommodate the complicating presence of censured data, a feature that commonly occurs in environmental data.

Physical controls on total and methylmercury concentrations in streams and lakes of the northeastern USA

USGS Publications Warehouse

Shanley, J.B.; Kamman, N.C.; Clair, T.A.; Chalmers, A.

2005-01-01

The physical factors controlling total mercury (HgT) and methylmercury (MeHg) concentrations in lakes and streams of northeastern USA were assessed in a regional data set containing 693 HgT and 385 corresponding MeHg concentrations in surface waters. Multiple regression models using watershed characteristics and climatic variables explained 38% or less of the variance in HgT and MeHg. Land cover percentages and soil permeability generally provided modest predictive power. Percent wetlands alone explained 19% of the variance in MeHg in streams at low-flow, and it was the only significant (p < 0.02) predictor for MeHg in lakes, albeit explaining only 7% of the variance. When stream discharge was added as a variable it became the dominant predictor for HgT in streams, improving the model r 2 from 0.19 to 0.38. Stream discharge improved the MeHg model more modestly, from r 2 of 0.25 to 0.33. Methylation efficiency (MeHg/HgT) was modeled well (r 2 of 0.78) when a seasonal term was incorporated (sine wave with annual period). Physical models explained 18% of the variance in fish Hg concentrations in 134 lakes and 55% in 20 reservoirs. Our results highlight the important role of seasonality and short-term hydrologic changes to the delivery of Hg to water bodies. ?? 2005 Springer Science+Business Media, Inc.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Little Laughery Creek, Ripley and Franklin counties, Indiana

USGS Publications Warehouse

Crawford, Charles G.; Wilber, William G.; Peters, James G.

1980-01-01

A digital model calibrated to conditions in Little Laughery Creek triutary and Little Laughery Creek, Ripley and Franklin Counties, Ind., was used to predict alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. Natural streamflow during the summer and annual 7-day, 10-year low flow is zero. Headwater flow upstream from the wastewater-treatment facilities consists solely of process cooling water from an industrial discharger. This flow is usually less than 0.5 cubic foot per second. Consequently, benefits from dilution are minimal. As a result, current and projected ammonia-nitrogen concentrations from the municipal discharges will result in in-stream ammonia-nitrogen concentrations that exceed the Indiana ammonia-nitrogen toxicity standards (maximum stream ammonia-nitrogen concentrations of 2.5 and 4.0 milligrams per liter during summer and winter low flows, respectively). Benthic-oxygen demand is probably the most significant factor affecting Little Laughery Creek and is probably responsible for the in-stream dissolved-oxygen concentration being less than the Indiana stream dissolved-oxygen standard (5.0 milligrams per liter) during two water-quality surveys. After municipal dischargers complete advanced waste-treatment facilities, benthic-oxygen demand should be less significant in the stream dissolved-oxygen dynamics. (USGS)

Escherichia coli Concentrations in Recreational Streams and Backcountry Drinking-Water Supplies in Shenandoah National Park, Virginia, 2005-2006

USGS Publications Warehouse

Hyer, Kenneth

2007-01-01

Although fecal contamination of streams is a problem of national scope, few investigations have been directed at relatively pristine streams in forested basins in national parks. With approximately 1.8 million visitors annually, Shenandoah National Park in Virginia is subject to extensive recreational use. The effects of these visitors and their recreational activities on fecal indicator bacteria levels in the streams are poorly understood and of concern for Shenandoah National Park managers. During 2005 and 2006, streams and springs in Shenandoah National Park were sampled for Escherichia coli (E. coli) concentrations. The first study objective was to evaluate the effects of recreational activities on E. coli concentrations in selected streams. Of the 20 streams that were selected, 14 were in basins with extensive recreational activity, and 6 were in control basins where minimal recreational activities occurred. Water-quality sampling was conducted during low-flow conditions during the relatively warm months, as this is when outdoor recreation and bacterial survivorship are greatest. Although most sampling was conducted during low-flow conditions, approximately three stormflow samples were collected from each stream. The second study objective was to evaluate E. coli levels in backcountry drinking-water supplies throughout Shenandoah National Park. Nineteen drinking-water supplies (springs and streams) were sampled two to six times each by Shenandoah National Park staff and analyzed by the U.S. Geological Survey for this purpose. The water-quality sampling results indicated relatively low E. coli concentrations during low-flow conditions, and no statistically significant increase in E. coli concentrations was observed in the recreational streams relative to the control streams. These results indicate that during low-flow conditions, recreational activities had no significant effect on E. coli concentrations. During stormflow conditions, E. coli concentrations increased by nearly a factor of 10 in both basin types, and the Virginia instantaneous water-quality standard for E. coli (235 colonies per 100 milliliters) frequently was exceeded. The sampling results from drinking-water supplies throughout Shenandoah National Park indicated relatively low E. coli concentrations in all springs that were sampled. Several of the streams that were sampled had slightly higher E. coli concentrations relative to the springs, but no E. coli concentrations exceeded the instantaneous water-quality standard. Although E. coli concentrations in all the drinking-water supplies were relatively low, Shenandoah National Park management continues to stress that all hikers must treat drinking water from all streams and springs prior to consumption. After determining that recreational activities in Shenandoah National Park did not have a statistically significant effect on low-flow E. coli concentrations, an additional concern was addressed regarding the quality of the water releases from the wastewater-treatment plants in the park. Sampling of three wastewater-treatment plant outfalls was conducted in 2006 to evaluate their effects on water quality. Samples were analyzed for E. coli and a collection of wastewater organic compounds that may be endocrine disruptors. Relatively elevated E. coli concentrations were observed in 2 of the 3 samples, and between 9 and 13 wastewater organic compounds were detected in the samples, including 3 known and 5 suspected endocrine-disrupting compounds.

N : P stoichiometry in a forested runoff during storm events: comparisons with regions and vegetation types.

PubMed

Guo, Lanlan; Chen, Yi; Zhang, Zhao; Fukushima, Takehiko

2012-01-01

Nitrogen and phosphorus are considered the most important limiting elements in terrestrial and aquatic ecosystems. however, very few studies have focused on which is from forested streams, a bridge between these two systems. To fill this gap, we examined the concentrations of dissolved N and P in storm waters from forested watersheds of five regions in Japan, to characterize nutrient limitation and its potential controlling factors. First, dissolved N and P concentrations and the N : P ratio on forested streams were higher during storm events relative to baseflow conditions. Second, significantly higher dissolved inorganic N concentrations were found in storm waters from evergreen coniferous forest streams than those from deciduous broadleaf forest streams in Aichi, Kochi, Mie, Nagano, and with the exception of Tokyo. Finally, almost all the N : P ratios in the storm water were generally higher than 34, implying that the storm water should be P-limited, especially for Tokyo.

N : P Stoichiometry in a Forested Runoff during Storm Events: Comparisons with Regions and Vegetation Types

PubMed Central

Guo, Lanlan; Chen, Yi; Zhang, Zhao; Fukushima, Takehiko

2012-01-01

Nitrogen and phosphorus are considered the most important limiting elements in terrestrial and aquatic ecosystems. however, very few studies have focused on which is from forested streams, a bridge between these two systems. To fill this gap, we examined the concentrations of dissolved N and P in storm waters from forested watersheds of five regions in Japan, to characterize nutrient limitation and its potential controlling factors. First, dissolved N and P concentrations and the N : P ratio on forested streams were higher during storm events relative to baseflow conditions. Second, significantly higher dissolved inorganic N concentrations were found in storm waters from evergreen coniferous forest streams than those from deciduous broadleaf forest streams in Aichi, Kochi, Mie, Nagano, and with the exception of Tokyo. Finally, almost all the N : P ratios in the storm water were generally higher than 34, implying that the storm water should be P-limited, especially for Tokyo. PMID:22547978

Atmospheric deposition effects on the chemistry of a stream in Northeastern Georgia

USGS Publications Warehouse

Buell, G.R.; Peters, N.E.

1988-01-01

The quantity and quality of precipitation and streamwater were measured from August 1985 through September 1986 in the Brier Creek watershed, a 440-ha drainage in the Southern Blue Ridge Province of northeastern Georgia, to determine stream sensitivity to acidic deposition. Precipitation samples collected at 2 sites had a volume-weighted average pH of 4.40 whereas stream samples collected near the mouth of Brier Creek had a discharge-weighted average pH of 6.70. Computed solute fluxes through the watershed and observed changes in streamwater chemistry during stormflow suggest that cation exchange, mineral weathering, SO42- adsorption by the soil, and groundwater discharge to the stream are probable factors affecting neutralization of precipitation acidity. Net solute fluxes for the watershed indicate that, of the precipitation input, > 99% of the H+, 93% of the NH4+ and NO3-, and 77% of the SO42- were retained. Sources within the watershed yielded base cations, Cl-, and HCO3- and accounted for 84, 47, and 100% of the net transport, respectively. Although streamwater SO42- and NO3- concentrations increased during stormflow, peak concentrations of these anions were much less than average concentrations in the precipitation. This suggests retention of these solutes occurs even when water residence time is short.The quantity and quality of precipitation and streamwater were measured from August 1985 through September 1986 in the Brier Creek watershed, a 440-ha drainage in the Southern Blue Ridge Province of northeastern Georgia, to determine stream sensitivity to acidic deposition. Precipitation samples collected at 2 sites had a volume-weighted average pH of 4.40 whereas stream samples collected near the mouth of Brier Creek had a discharge-weighted average pYH of 6.70. Computed solute fluxes through the watershed and observed changes in streamwater chemistry drying stormflow suggest that cation exchange, mineral weathering, SO42- adsorption by the soil, and groundwater discharge to the stream are probable factors affecting neutralization of precipitation acidity. Although streamwater SO42- and NO3- concentrations increased during stormflow, peak concentrations of these anions were much less than average concentrations in the precipitation. This suggests retention of these solutes occurs even when water residence time is short.

Legacy Nitrate Impacts on Groundwater and Streams

NASA Astrophysics Data System (ADS)

Tesoriero, A. J.; Juckem, P. F.; Miller, M. P.

2017-12-01

Decades of recharge of high-nitrate groundwater have created a legacy—a mass of high-nitrate groundwater—that has implications for future nitrate concentrations in groundwater and in streams. In the United States, inorganic nitrogen fertilizer applications to the land surface have increased ten-fold since 1950, resulting in sharp increases in nitrate concentrations in recharging groundwater, which pose a risk to deeper groundwater and streams. This study assesses the factors that control time lags and eventual concentrations of legacy nitrate in groundwater and streams. Results from the USGS National Water-Quality Assessment Project are presented which elucidate nitrate trends in recharging groundwater, delineate redox zones and assess groundwater and stream vulnerability to legacy nitrate sources on a regional scale. This study evaluated trends and transformations of agricultural chemicals based on groundwater age and water chemistry data along flow paths from recharge areas to streams at 20 study sites across the United States. Median nitrate recharge concentrations in these agricultural areas have increased markedly over the last 50 years, from 4 to 7.5 mg N/L. The effect that nitrate accumulation in shallow aquifers will have on drinking water quality and stream ecosystems is dependent on the redox zones encountered along flow paths and on the age distribution of nitrate discharging to supply wells and streams. Delineating redox zones on a regional scale is complicated by the spatial variability of reaction rates. To overcome this limitation, we applied logistic regression and machine learning techniques to predict the probability of a specific redox condition in groundwater in the Chesapeake Bay watershed and the Fox-Wolf-Peshtigo study area in Wisconsin. By relating redox-active constituent concentrations in groundwater samples to indicators of residence time and/or electron donor availability, we were able to delineate redox zones on a regional scale - an important indicator of groundwater vulnerability and the vulnerability of streams to legacy nitrate sources.

Herbicides and herbicide degradation products in upper midwest agricultural streams during august base-flow conditions

USGS Publications Warehouse

Kalkhoff, S.J.; Lee, K.E.; Porter, S.D.; Terrio, P.J.; Thurman, E.M.

2003-01-01

Herbicide concentrations in streams of the U.S. Midwest have been shown to decrease through the growing season due to a variety of chemical and physical factors. The occurrence of herbicide degradation products at the end of the growing season is not well known. This study was conducted to document the occurrence of commonly used herbicides and their degradation products in Illinois, Iowa, and Minnesota streams during base-flow conditions in August 1997. Atrazine, the most frequently detected herbicide (94%), was present at relatively low concentrations (median 0.17 μg L−1). Metolachlor was detected in 59% and cyanazine in 37% of the samples. Seven of nine compounds detected in more than 50% of the samples were degradation products. The total concentration of the degradation products (median of 4.4 μg L−1) was significantly greater than the total concentration of parent compounds (median of 0.26 μg L−1). Atrazine compounds were present less frequently and in significantly smaller concentrations in streams draining watersheds with soils developed on less permeable tills than in watersheds with soils developed on more permeable loess. The detection and concentration of triazine compounds was negatively correlated with antecedent rainfall (April–July). In contrast, acetanalide compounds were positively correlated with antecedant rainfall in late spring and early summer that may transport the acetanalide degradates into ground water and subsequently into nearby streams. The distribution of atrazine degradation products suggests regional differences in atrazine degradation processes.

Global pressures, specific responses: effects of nutrient enrichment in streams from different biomes

NASA Astrophysics Data System (ADS)

Artigas, Joan; García-Berthou, Emili; Bauer, Delia E.; Castro, Maria I.; Cochero, Joaquín; Colautti, Darío C.; Cortelezzi, Agustina; Donato, John C.; Elosegi, Arturo; Feijoó, Claudia; Giorgi, Adonis; Gómez, Nora; Leggieri, Leonardo; Muñoz, Isabel; Rodrigues-Capítulo, Alberto; Romaní, Anna M.; Sabater, Sergi

2013-03-01

We assessed the effects of nutrient enrichment on three stream ecosystems running through distinct biomes (Mediterranean, Pampean and Andean). We increased the concentrations of N and P in the stream water 1.6-4-fold following a before-after control-impact paired series (BACIPS) design in each stream, and evaluated changes in the biomass of bacteria, primary producers, invertebrates and fish in the enriched (E) versus control (C) reaches after nutrient addition through a predictive-BACIPS approach. The treatment produced variable biomass responses (2-77% of explained variance) among biological communities and streams. The greatest biomass response was observed for algae in the Andean stream (77% of the variance), although fish also showed important biomass responses (about 9-48%). The strongest biomass response to enrichment (77% in all biological compartments) was found in the Andean stream. The magnitude and seasonality of biomass responses to enrichment were highly site specific, often depending on the basal nutrient concentration and on windows of ecological opportunity (periods when environmental constraints other than nutrients do not limit biomass growth). The Pampean stream, with high basal nutrient concentrations, showed a weak response to enrichment (except for invertebrates), whereas the greater responses of Andean stream communities were presumably favored by wider windows of ecological opportunity in comparison to those from the Mediterranean stream. Despite variation among sites, enrichment globally stimulated the algal-based food webs (algae and invertebrate grazers) but not the detritus-based food webs (bacteria and invertebrate shredders). This study shows that nutrient enrichment tends to globally enhance the biomass of stream biological assemblages, but that its magnitude and extent within the food web are complex and are strongly determined by environmental factors and ecosystem structure.

High levels of endocrine pollutants in US streams during low flow due to insufficient wastewater dilution

NASA Astrophysics Data System (ADS)

Rice, Jacelyn; Westerhoff, Paul

2017-08-01

Wastewater discharges from publicly owned treatment works are a significant source of endocrine disruptors and other contaminants to the aquatic environment in the US. Although remaining pollutants in wastewater pose environmental risks, treated wastewater is also a primary source of stream flow, which in turn is critical in maintaining many aquatic and riparian wildlife habitats. Here we calculate the dilution factor--the ratio of flow in the stream receiving discharge to the flow of wastewater discharge--for over 14,000 receiving streams in the continental US using streamflow observations and a spatially explicit watershed-scale hydraulic model. We found that wastewater discharges make up more than 50% of in-stream flow for over 900 streams. However, in 1,049 streams that experienced exceptional low-flow conditions, the dilution factors in 635 of those streams fell so low during those conditions that the safety threshold for concentrations of one endocrine disrupting compound was exceeded, and in roughly a third of those streams, the threshold was exceeded for two compounds. We suggest that streams are vulnerable to public wastewater discharge of contaminants under low-flow conditions, at a time when wastewater discharges are likely to be most important for maintaining stream flow for smaller sized river systems.

An empirical approach to modeling methylmercury concentrations in an Adirondack stream watershed

USGS Publications Warehouse

Burns, Douglas A.; Nystrom, Elizabeth A.; Wolock, David M.; Bradley, Paul M.; Riva-Murray, Karen

2014-01-01

Inverse empirical models can inform and improve more complex process-based models by quantifying the principal factors that control water quality variation. Here we developed a multiple regression model that explains 81% of the variation in filtered methylmercury (FMeHg) concentrations in Fishing Brook, a fourth-order stream in the Adirondack Mountains, New York, a known “hot spot” of Hg bioaccumulation. This model builds on previous observations that wetland-dominated riparian areas are the principal source of MeHg to this stream and were based on 43 samples collected during a 33 month period in 2007–2009. Explanatory variables include those that represent the effects of water temperature, streamflow, and modeled riparian water table depth on seasonal and annual patterns of FMeHg concentrations. An additional variable represents the effects of an upstream pond on decreasing FMeHg concentrations. Model results suggest that temperature-driven effects on net Hg methylation rates are the principal control on annual FMeHg concentration patterns. Additionally, streamflow dilutes FMeHg concentrations during the cold dormant season. The model further indicates that depth and persistence of the riparian water table as simulated by TOPMODEL are dominant controls on FMeHg concentration patterns during the warm growing season, especially evident when concentrations during the dry summer of 2007 were less than half of those in the wetter summers of 2008 and 2009. This modeling approach may help identify the principal factors that control variation in surface water FMeHg concentrations in other settings, which can guide the appropriate application of process-based models.

Spatial and temporal variation in microcystins occurrence in wadeable streams in the southeastern USA

USGS Publications Warehouse

Loftin, Keith A.; Clark, Jimmy M.; Journey, Celeste A.; Kolpin, Dana W.; Van Metre, Peter C.; Bradley, Paul M.

2016-01-01

Despite historical observations of potential microcystin-producing cyanobacteria (including Leptolyngbya,Phormidium, Pseudoanabaena, and Anabaena species) in 74% of headwater streams in Alabama, Georgia, South Carolina, and North Carolina (USA) from 1993 to 2011, fluvial cyanotoxin occurrence has not been systematically assessed in the southeastern United States. To begin to address this data gap, a spatial reconnaissance of fluvial microcystin concentrations was conducted in 75 wadeable streams in the Piedmont region (southeastern USA) during June 2014. Microcystins were detected using enzyme-linked immunosorbent assay (limit = 0.10 µg/L) in 39% of the streams with mean, median, and maximum detected concentrations of 0.29 µg/L, 0.11 µg/L, and 3.2 µg/L, respectively. Significant (α = 0.05) correlations were observed between June 2014 microcystin concentrations and stream flow, total nitrogen to total phosphorus ratio, and water temperature; but each of these factors explained 38% or less of the variability in fluvial microcystins across the region. Temporal microcystin variability was assessed monthly through October 2014 in 5 of the streams where microcystins were observed in June and in 1 reference location; microcystins were repeatedly detected in all but the reference stream. Although microcystin concentrations in the present study did not exceed World Health Organization recreational guidance thresholds, their widespread occurrence demonstrates the need for further investigation of possible in-stream environmental health effects as well as potential impacts on downstream lakes and reservoirs. Environ Toxicol Chem 2016;9999:1–7. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

Surface-water-quality assessment of the lower Kansas River basin, Kansas and Nebraska; results of investigations, 1987-90

USGS Publications Warehouse

Helgesen, J.O.

1995-01-01

Surface-water-quality conditions and trends were assessed in the lower Kansas River Basin, which drains about 15,300 square miles of mainly agricultural land in southeast Nebraska and northeast Kansas. On the basis of established water-quality criteria, most streams in the basin were suitable for uses such as public-water supply, irrigation, and maintenance of aquatic life. However, most concerns identified from a previous analysis of available data through 1986 are substantiated by analysis of data for May 1987 through April 1990. Less-than-normal precipitation and runoff during 1987-90 affected surface-water quality and are important factors in the interpretation of results.Dissolved-solids concentrations in the main stem Kansas River during May 1987 through April 1990 commonly exceeded 500 milligrams per liter, which may be of concern for public-water supplies and for the irrigation of sensitive crops. Large concentrations of chloride in the Kansas River are derived from ground water discharging in the Smoky Hill River Basin west of the study unit. Trends of increasing concentrations of some dissolved major ions were statistically significant in the northwestern part of the study unit, which could reflect substantial increases in irrigated acreage.The largest concentrations of suspended sediment in streams during May 1987 through April 1990 were associated with high-density cropland in areas of little local relief and medium-density irrigated cropland in more dissected areas. The smallest concentrations were measured downstream from large reservoirs and in streams draining areas having little or no row-crop cultivation. Mean annual suspended-sediment transport rates in the main stem Kansas River increased substantially in the downstream direction. No conclusions could be reached concerning the relations of suspended-sediment transport, yields, or trends to natural and human factors.The largest sources of nitrogen and phosphorus in the study unit were fertilizer and livestock. Nitrate-nitrogen concentrations in stream-water samples did not exceed 10 milligams per liter; relatively large concentrations in the northwestern part of the study unit were associated with fertilizer application. Concentrations of total phosphorus generally were largest in the northwestern part of the study unit, which probably relates to the prevalence of cultivated land, fertilizer application, and livestock wastes.Deficiencies in dissolved-oxygen concentrations in streams occurred locally, as a result of discharges from wastewater-treatment plants, algal respiration, and inadequate reaeration associated with small streamflow. Large densities of a fecal-indicator bacterium, Escherichia coli, were associated with discharges from municipal wastewater-treatment plants and, especially in the northwestern part of the study unit, with transport of fecaThe largest concentrations of the herbicide atrazine generally were measured where the largest quantities of atrazine were applied to the land. Large atrazine concentrations, 10 to 20 micrograms per liter, were measured most frequently in unregulated principal streams during May and June. Downstream of reservoirs, the seasonal variability of atrazine concentrations was decreased compared to that of inflowing streams.

Dynamics of stream water TOC concentrations in a boreal headwater catchment: Controlling factors and implications for climate scenarios

NASA Astrophysics Data System (ADS)

Köhler, S. J.; Buffam, I.; Seibert, J.; Bishop, K. H.; Laudon, H.

2009-06-01

SummaryTwo different but complementary modelling approaches for reproducing the observed dynamics of total organic carbon (TOC) in a boreal stream are presented. One is based on a regression analysis, while the other is based on riparian soil conditions using a convolution of flow and concentration. Both approaches are relatively simple to establish and help to identify gaps in the process understanding of the TOC transport from soils to catchments runoff. The largest part of the temporal variation of stream TOC concentrations (4-46 mg L -1) in a forested headwater stream in the boreal zone in northern Sweden may be described using a four-parameter regression equation that has runoff and transformed air temperature as sole input variables. Runoff is assumed to be a proxy for soil wetness conditions and changing flow pathways which in turn caused most of the stream TOC variation. Temperature explained a significant part of the observed inter-annual variability. Long-term riparian hydrochemistry in soil solutions within 4 m of the stream also captures a surprisingly large part of the observed variation of stream TOC and highlights the importance of riparian soils. The riparian zone was used to reproduce stream TOC with the help of a convolution model based on flow and average riparian chemistry as input variables. There is a significant effect of wetting of the riparian soil that translates into a memory effect for subsequent episodes and thus contributes to controlling stream TOC concentrations. Situations with high flow introduce a large amount of variability into stream water TOC that may be related to memory effects, rapid groundwater fluctuations and other processes not identified so far. Two different climate scenarios for the region based on the IPCC scenarios were applied to the regression equation to test what effect the expected increase in precipitation and temperature and resulting changes in runoff would have on stream TOC concentrations assuming that the soil conditions remain unchanged. Both scenarios resulted in a mean increase of stream TOC concentrations of between 1.5 and 2.5 mg L -1 during the snow free season, which amounts to approximately 15% more TOC export compared to present conditions. Wetter and warmer conditions in the late autumn led to a difference of monthly average TOC of up to 5 mg L -1, suggesting that stream TOC may be particularly susceptible to climate variability during this season.

Root uptake and translocation of perfluorinated alkyl acids by three hydroponically grown crops.

PubMed

Felizeter, Sebastian; McLachlan, Michael S; De Voogt, Pim

2014-04-16

Tomato, cabbage, and zucchini plants were grown hydroponically in a greenhouse. They were exposed to 14 perfluorinated alkyl acids (PFAAs) at four different concentrations via the nutrient solution. At maturity the plants were harvested, and the roots, stems, leaves, twigs (where applicable), and edible parts (tomatoes, cabbage head, zucchinis) were analyzed separately. Uptake and transfer factors were calculated for all plant parts to assess PFAA translocation and distribution within the plants. Root concentration factors were highest for long-chain PFAAs (>C11) in all three plant species, but these chemicals were not found in the edible parts. All other PFAAs were present in all above-ground plant parts, with transpiration stream concentration factors (TSCFs) of 0.05-0.25. These PFAAs are taken up with the transpiration stream and accumulate primarily in the leaves. Although some systematic differences were observed, overall their uptake from nutrient solution to roots and their further distribution within the plants were similar between plant species and among PFAAs.

The on-line characterization of a radium slurry by gamma-ray spectrometry.

PubMed

Philips, S; Croft, S

2005-01-01

We have developed an in-line monitor to directly measure the (226)Ra concentration in a nuclear waste stream using quantitative gamma-ray spectrometry applied to the 186keV emission. The waste stream is in the form of a slurry composed of the solid waste material mixed with water. The concentration measurement includes a self-attenuation correction factor determined from a transmission measurement using the 122keV gamma from (57)Co. Presented here is the model for the measurement system and results from some initial tests.

Using SPARROW to Model Total Nitrogen Sources, and Transport in Rivers and Streams of California and Adjacent States, U.S.A

NASA Astrophysics Data System (ADS)

Saleh, D.; Domagalski, J. L.

2012-12-01

Sources and factors affecting the transport of total nitrogen are being evaluated for a study area that covers most of California and some areas in Oregon and Nevada, by using the SPARROW model (SPAtially Referenced Regression On Watershed attributes) developed by the U.S. Geological Survey. Mass loads of total nitrogen calculated for monitoring sites at stream gauging stations are regressed against land-use factors affecting nitrogen transport, including fertilizer use, recharge, atmospheric deposition, stream characteristics, and other factors to understand how total nitrogen is transported under average conditions. SPARROW models have been used successfully in other parts of the country to understand how nutrients are transported, and how management strategies can be formulated, such as with Total Maximum Daily Load (TMDL) assessments. Fertilizer use, atmospheric deposition, and climatic data were obtained for 2002, and loads for that year were calculated for monitored streams and point sources (mostly from wastewater treatment plants). The stream loads were calculated by using the adjusted maximum likelihood estimation method (AMLE). River discharge and nitrogen concentrations were de-trended in these calculations in order eliminate the effect of temporal changes on stream load. Effluent discharge information as well as total nitrogen concentrations from point sources were obtained from USEPA databases and from facility records. The model indicates that atmospheric deposition and fertilizer use account for a large percentage of the total nitrogen load in many of the larger watersheds throughout the study area. Point sources, on the other hand, are generally localized around large cities, are considered insignificant sources, and account for a small percentage of the total nitrogen loads throughout the study area.

Linking land-use type and stream water quality using spatial data of fecal indicator bacteria and heavy metals in the Yeongsan river basin.

PubMed

Kang, Joo-Hyon; Lee, Seung Won; Cho, Kyung Hwa; Ki, Seo Jin; Cha, Sung Min; Kim, Joon Ha

2010-07-01

This study reveals land-use factors that explain stream water quality during wet and dry weather conditions in a large river basin using two different linear models-multiple linear regression (MLR) models and constrained least squares (CLS) models. Six land-use types and three topographical parameters (size, slope, and permeability) of the watershed were incorporated into the models as explanatory variables. The suggested models were then demonstrated using a digitized elevation map in conjunction with the land-use and the measured concentration data for Escherichia coli (EC), Enterococci bacteria (ENT), and six heavy metal species collected monthly during 2007-2008 at 50 monitoring sites in the Yeongsan Watershed, Korea. The results showed that the MLR models can be a powerful tool for predicting the average concentrations of pollutants in stream water (the Nash-Sutcliffe (NS) model efficiency coefficients ranged from 0.67 to 0.95). On the other hand, the CLS models, with moderately good prediction performance (the NS coefficients ranged 0.28-0.85), were more suitable for quantifying contributions of respective land-uses to the stream water quality. The CLS models suggested that industrial and urban land-uses are major contributors to the stream concentrations of EC and ENT, whereas agricultural, industrial, and mining areas were significant sources of many heavy metal species. In addition, the slope, size, and permeability of the watershed were found to be important factors determining the extent of the contribution from each land-use type to the stream water quality. The models proposed in this paper can be considered useful tools for developing land cover guidelines and for prioritizing locations for implementing management practices to maintain stream water quality standard in a large river basin. Copyright 2010 Elsevier Ltd. All rights reserved.

Biogeochemistry of the Amazon River Basin: the role of aquatic ecosystems in the Amazon functioning

NASA Astrophysics Data System (ADS)

Victoria, R. L.; Ballester, V. R.; Krushe, A. V.; Richey, J. E.; Aufdenkampe, A. K.; Kavaguishi, N. L.; Gomes, B. M.; Victoria, D. D.; Montebello, A. A.; Niell, C.; Deegan, L.

2004-12-01

In this study we present the results of an integrated analysis of physical and anthropogenic controls of river biogeochemistry in Amazônia. At the meso-scale level, our results show that both soil properties and land use are the main drivers of river biogeochemistry and metabolism, with pasture cover and soil exchange cation capacity explaining 99% (p < 0.01) of the variability observed in surface water ions and nutrients concentrations. In small rivers, forest clearing can increase cations, P and C inputs. P and light are the main PPL limiting factors in forested streams, while in pasture streams N becomes limiting. P export to streams may increase or remain nearly undetectable after forest-to-pasture conversion, depending on soil type. Pasture streams on Oxisols have very low P export, while on Ultisols P export is increased. Conversions of forest to pasture leads to extensive growth of in channel Paspalum resulting in higher DOC concentrations and respiration rates. Pasture streams have higher DOC fluxes when compared to the forest ones. In pasture areas the soil are compacted, there is less infiltration and higher surface run off, leaching soil superficial layers and caring more DOC to the streams. In forest areas infiltration is deeper into the soils and canopy interaction is higher. Mineralogy and soil properties are key factors determining exports of nutrients to streams. Therefore, land use change effects on nutrient export from terrestrial to aquatic ecosystems and the atmosphere must be understood within the context of varying soil properties across the Amazon Basin.

Evaluation of Measurements Collected with Multi-Parameter Continuous Water-Quality Monitors in Selected Illinois Streams, 2001-03

USGS Publications Warehouse

Groschen, George E.; King, Robin B.

2005-01-01

Eight streams, representing a wide range of environmental and water-quality conditions across Illinois, were monitored from July 2001 to October 2003 for five water-quality parameters as part of a pilot study by the U.S. Geological Survey (USGS) in cooperation with the Illinois Environmental Protection Agency (IEPA). Continuous recording multi-parameter water-quality monitors were installed to collect data on water temperature, dissolved-oxygen concentrations, specific conductivity, pH, and turbidity. The monitors were near USGS streamflow-gaging stations where stage and streamflow are continuously recorded. During the study period, the data collected for these five parameters generally met the data-quality objectives established by the USGS and IEPA at all eight stations. A similar pilot study during this period for measurement of chlorophyll concentrations failed to achieve the data-quality objectives. Of all the sensors used, the temperature sensors provided the most accurate and reliable measurements (generally within ?5 percent of a calibrated thermometer reading). Signal adjustments and calibration of all other sensors are dependent upon an accurate and precise temperature measurement. The dissolved-oxygen sensors were the next most reliable during the study and were responsive to changing conditions and accurate at all eight stations. Specific conductivity was the third most accurate and reliable measurement collected from the multi-parameter monitors. Specific conductivity at the eight stations varied widely-from less than 40 microsiemens (?S) at Rayse Creek near Waltonville to greater than 3,500 ?S at Salt Creek at Western Springs. In individual streams, specific conductivity often changed quickly (greater than 25 percent in less than 3 hours) and the sensors generally provided good to excellent record of these variations at all stations. The widest range of specific-conductivity measurements was in Salt Creek at Western Springs in the Greater Chicago metropolitan area. Unlike temperature, dissolved oxygen, and specific conductivity that have been typically measured over a wide range of historical streamflow conditions in many streams, there are few historical turbidity data and the full range of turbidity values is not well known for many streams. Because proposed regional criteria for turbidity in regional streams are based on upper 25th percentiles of concentration in reference streams, accurate determination of the distribution of turbidity in monitored streams is important. Digital data from all five sensors were recorded within each of the eight sondes deployed in the streams and in automated data recorders in the nearby streamflow-gaging houses at each station. The data recorded on each sonde were retrieved to a field laptop computer at each station visit. The feasibility of transmitting these data in near-real time to a central processing point for dissemination on the World-Wide Web was tested successfully. Data collected at all eight stations indicate that a number of factors affect the dissolved-oxygen concentration in the streams and rivers monitored. These factors include: temperature, biological activity, nutrient runoff, and weather (storm runoff). During brief periods usually in late summer, dissolved-oxygen concentrations in half or more of the eight streams and rivers monitored were below the 5 milligrams per liter minimum established by the Illinois Pollution Control Board to protect aquatic life. Because the streams monitored represent a wide range in water-quality and environmental conditions, including diffuse (non-point) runoff and wastewater-effluent contributions, this result indicates that deleterious low dissolved-oxygen concentrations during late summer may be widespread in Illinois streams.

Water-quality assessment of the Trinity River Basin, Texas - Nutrients in streams draining an agricultural and an urban area, 1993-95

USGS Publications Warehouse

Land, Larry F.; Shipp, Allison A.

1996-01-01

Water samples collected from streams draining an agricultural area in the west-central part of the Trinity River Basin upstream from the Richland-Chambers Reservoir and from streams draining an urban area in the Dallas-Fort Worth metropolitan area during March 1993 - September 1995 were analyzed for nutrients (nitrogen and phosphorus compounds). A comparison of the data for agricultural and urban streams shows the maximum concentration of total nitrogen is from an urban stream and the maximum concentration of total phosphorus is from an agricultural stream. One-half of the samples have total nitrogen concentrations equal to or less than 1.1 and 1.0 milligrams per liter in the agricultural and urban streams, respectively; and one-half of the samples have total phosphorous concentrations equal to or less than 0.04 and 0.05 milligram per liter in the agricultural and urban streams, respectively. The highest concentrations of total nitrogen in both types of streams are in the spring. The minimum concentrations of total nitrogen are during the summer in the agricultural streams and during the winter in the urban streams. Concentrations of total phosphorus in agricultural streams show negligible seasonal variability. The highest concentrations of total phosphorus are in spring and possibly late summer in the urban streams. In the midrange of streamflow in the urban streams and throughout the range of streamflow in the agricultural streams, concentrations of total nitrogen increase. Concentrations of total phosphorus increase with streamflow in the middle and upper ranges of streamflow in both agricultural and urban streams.

In-Stream Sediment Dynamics for predicted environmental concentration calculations of plant protection products in the FOCUSSW Scenarios

NASA Astrophysics Data System (ADS)

Strehmel, Alexander; Erzgräber, Beate; Gottesbüren, Bernhard

2016-04-01

The exposure assessment for the EU registration procedure of plant protection products (PPP), which is based on the 'Forum for the co-ordination of pesticide fate models and their use' (FOCUS), currently considers only periods of 12-16 months for the exposure assessment in surface water bodies. However, in a recent scientific opinion of the European Food Safety Authority (EFSA) it is argued that in a multi-year exposure assessment, the accumulation of PPP substances in river sediment may be a relevant process. Therefore, the EFSA proposed to introduce a sediment accumulation factor in order to account for enrichment of PPP substances over several years in the sediment. The calculation of this accumulation factor, however, would consider degradation in sediment as the only dissipation path, and does not take into account riverine sediment dynamics. In order to assess the influence of deposition and the possible extent of substance accumulation in the sediment phase, the hydraulic model HEC-RAS was employed for an assessment of in-stream sediment dynamics of the FOCUS stream scenarios. The model was parameterized according to the stream characteristics of the FOCUS scenarios and was run over a period of 20 years. The results show that with the distribution of grain sizes and the ranges of flow velocity in the FOCUS streams the main sediment process in the streams is transport. First modeling results suggest that about 80% of the eroded sediment mass from the adjacent field are transported to the downstream end of the stream and out of the system, while only about 20% are deposited in the river bed. At the same time, only about 30% of in-stream sediment mass stems from the adjacent field and is associated with PPP substance, while the remaining sediment consists of the substance-free base sediment concentration regarded in the scenarios. With this, the hydraulic modelling approach is able to support the development of a meaningful sediment accumulation factor by considering in-stream sediment dynamics and estimating long-term sediment deposition and substance burial in the river bed. At last, the study shows that the development of a scientifically sound and justifiable sediment accumulation factor for a long-term exposure assessment is only possible by considering the relevant riverine sediment processes.

Assessment of selected inorganic constituents in streams in the Central Arizona Basins Study Area, Arizona and northern Mexico, through 1998

USGS Publications Warehouse

Anning, David W.

2003-01-01

Stream properties and water-chemistry constituent concentrations from data collected by the National Water-Quality Assessment and other U.S. Geological Survey water-quality programs were analyzed to (1) assess water quality, (2) determine natural and human factors affecting water quality, and (3) compute stream loads for the surface-water resources in the Central Arizona Basins study area. Stream temperature, pH, dissolved-oxygen concentration and percent saturation, and dissolved-solids, suspended-sediment, and nutrient concentration data collected at 41 stream-water quality monitoring stations through water year 1998 were used in this assessment. Water-quality standards applicable to the stream properties and water-chemistry constituent concentration data for the stations investigated in this study generally were met, although there were some exceedences. In a few samples from the White River, the Black River, and the Salt River below Stewart Mountain Dam, the pH in reaches designated as a domestic drinking water source was higher than the State of Arizona standard. More than half of the samples from the Salt River below Stewart Mountain Dam and almost all of the samples from the stations on the Central Arizona Project Canal?two of the three most important surface-water sources used for drinking water in the Central Arizona Basins study area?exceeded the U.S. Environmental Protection Agency drinking water Secondary Maximum Contaminant Level for dissolved solids. Two reach-specific standards for nutrients established by the State of Arizona were exceeded many times: (1) the annual mean concentration of total phosphorus was exceeded during several years at stations on the main stems of the Salt and Verde Rivers, and (2) the annual mean concentration of total nitrogen was exceeded during several years at the Salt River near Roosevelt and at the Salt River below Stewart Mountain Dam. Stream properties and water-chemistry constituent concentrations were related to streamflow, season, water management, stream permanence, and land and water use. Dissolved-oxygen percent saturation, pH, and nutrient concentrations were dependent on stream regulation, stream permanence, and upstream disposal of wastewater. Seasonality and correlation with streamflow were dependant on stream regulation, stream permanence, and upstream disposal of wastewater. Temporal trends in streamflow, stream properties, and water-chemistry constituent concentrations were common in streams in the Central Arizona Basins study area. Temporal trends in the streamflow of unregulated perennial reaches in the Central Highlands tended to be higher from 1900 through the 1930s, lower from the 1940s through the 1970s, and high again after the 1970s. This is similar to the pattern observed for the mean annual precipitation for the Southwestern United States and indicates long-term trends in flow of streams draining the Central Highlands were driven by long-term trends in climate. Streamflow increased over the period of record at stations on effluent-dependent reaches as a result of the increase in the urban population and associated wastewater returns to the Salt and Gila Rivers in the Phoenix metropolitan area and the Santa Cruz River in the Tucson metropolitan area. Concentrations of dissolved solids decreased in the Salt River below Stewart Mountain Dam and in the Verde River below Bartlett Dam. This decrease represents an improvement in the water quality and resulted from a concurrent increase in the amount of runoff entering the reservoirs. Stream loads of water-chemistry constituents were compared at different locations along the streams with one another, and stream loads were compared to upstream inputs of the constituent from natural and anthropogenic sources to determine the relative importance of different sources and to determine the fate of the water-chemistry constituent. Of the dissolved solids transported into the Basin and Range Lowlands each year

Sensitivity of Stream Methyl Hg Concentrations to Environmental Change in the Adirondack Mountains of New York, USA

NASA Astrophysics Data System (ADS)

Burns, D. A.; Riva-Murray, K.; Nystrom, E.; Millard, G.; Driscoll, C. T.

2014-12-01

The Adirondacks of New York have high levels of mercury (Hg) bioaccumulation as demonstrated by a region-wide fish consumption advisory for children and women who may become pregnant. The source of this Hg is atmospheric deposition that originates from regional, continental, and global emissions. Soils in the region have large Hg stores equivalent to several decades of atmospheric deposition suggesting that the processes controlling Hg transport from soils to surface waters may greatly affect Hg concentrations and loads in surface waters. Furthermore, Hg can be converted to its neuro-toxic methyl form (MeHg), particularly in riparian and wetland soils where biogeochemical conditions favor net methylation. We measured MeHg concentrations during 33 months at Fishing Brook, a 65 km2 catchment in the upper Hudson River basin in the Adirondacks. Seasonal variation in stream MeHg concentrations was more than tenfold, consistent with temperature-driven variation in net methylation rates in soils and sediment. These data also indicate greater than twofold annual variation in stream MeHg concentrations among the three monitored growing seasons. The driest growing season had the lowest MeHg concentrations, and these values were greater during the two wetter growing seasons. We hypothesize that contact of the riparian water table with abundant organic matter and MeHg stored in the shallowest soil horizons is a dominant control on MeHg transport to the stream. An empirical model was developed that accounted for 81% of the variation in stream MeHg concentrations. Water temperature and the length of time the simulated riparian water table remained in the shallow soil were key predictive variables, highlighting the sensitivity of MeHg to climatic variation. Future changes in other factors such as Hg emissions and deposition and acid deposition will likely also influence stream MeHg concentrations and loads. For example, lime application to an Adirondack stream to increase pH and enhance ecosystem recovery from acidification has increased MeHg concentrations, which may be associated with parallel increases in dissolved organic carbon concentrations. Future changes in the Hg cycle of this region will likely be complex, reflecting changes in climatic drivers and emissions of Hg and other air pollutants.

Water quality, physical habitat, and fish community composition in streams in the Twin Cities metropolitan area, Minnesota, 1997-98

USGS Publications Warehouse

Talmage, Philip J.; Lee, Kathy E.; Goldstein, Robert M.; Anderson, Jesse P.; Fallon, James D.

1999-01-01

Water quality, physical habitat, and fish-community composition were characterized at 13 Twin Cities metropolitan area streams during low-flow conditions, September 1997. Fish communities were resampled during September 1998. Sites were selected based on a range of human population density. Nutrient concentrations were generally low, rarely exceeding concentrations found in agricultural streams or water-quality criteria. Seventeen pesticides and five pesticide metabolites were detected, with atrazine being the only pesticide detected at all 13 streams. Colony counts of fecal coliform bacteria ranged from 54 to greater than 11,000 colonies per 100 mL. Instream fish habitat was sparse with little woody debris and few boulders, cobble, or other suitable fish habitat. Thirty-eight species and one hybrid from 10 families were collected. Fish communities were characterized by high percentages of omnivores and tolerant species with few intolerant species. Index of Biotic Integrity scores were low, with most streams rating fair to very poor. Percent impervious surface was positively correlated with sodium and chloride concentrations and human population density, but was negatively correlated with fish species richness and diversity. Urban land use and human population density influence fish communities and water quality in Twin Cities metropolitan area streams. Other factors that may influence fish community composition include percent impervious cover, water chemistry, water temperature, geomorphology, substrate, instream habitat, and migration barriers.

Connection to deep groundwater alters ecosystem carbon fluxes and budgets: an example from a Costa Rican rainforest (Invited)

NASA Astrophysics Data System (ADS)

Genereux, D. P.; Osburn, C. L.; Nagy, L.; Oberbauer, S. F.; Rojas-Jiménez, L. D.

2013-12-01

Field studies of watershed carbon (C) fluxes and budgets are critical for understanding the C cycle, but the role of deep regional groundwater is poorly known and field examples are lacking. Discharge of regional groundwater has a major effect on C concentrations and fluxes in a lowland Costa Rican rainforest, observable through chemical, isotopic, and flux signals in groundwater, surface water, and air, and driven largely by the elevated dissolved inorganic C (DIC) in regional groundwater. Comparing two watersheds with different inputs of high-DIC regional groundwater (the Taconazo with none and the Arboleda with about 40% of stream discharge due to regional groundwater), the Arboleda has a higher stream DIC concentration (factor of ~12) and stream export of DIC (factor of ~70). Stream δ13C-DIC is higher in the Arboleda, -4.4‰ vs. -22.4‰, due to the influence of regional groundwater. A major question is the fate of old DIC discharged to streams by regional groundwater (i.e., uptake via in-stream photosynthesis vs. export by stream discharge or stream degassing). Particulate organic C (POC) δ13C values and C:N ratios were similar in the two streams and typical of soil organic matter from terrestrial C3 plants, suggesting little incorporation of DIC from regional groundwater into POC in the Arboleda stream (i.e., little algal production from old DIC). This finding is consistent with the large DIC export for the Arboleda. DIC from regional groundwater experiences little to no within-watershed sequestration, and thus augments the C flux out of the watershed with stream flow and, based on preliminary estimates, the degassing flux from the stream. Also, in air collected above the two streams in the early morning before daytime mixing of the canopy air, we found higher CO2 concentrations and δ13C-CO2 above the Arboleda compared to the Taconazo, consistent with an enhanced flux of isotopically-heavy CO2 from the Arboleda stream. Dissolved organic matter (DOM) also differs between the two watersheds. Slope ratio, a property of the light absorbance by DOM, was higher in the Arboleda than in the Taconazo, consistent with the DOM from regional groundwater being lower in molecular mass and/or weakly-aromatic (perhaps more degraded after its long subsurface residence time, ~3000 yr). Preliminary data suggest older DOM from regional groundwater is less bioavailable in rainforest streams. Regional groundwater inputs may alter watershed export of DOC (the C in DOM) in two ways: additional input of DOM to the watershed, and input of DOM that is more likely to experience hydrologic export from the watershed. Correct interpretation of the C source/sink status of this ecosystem from field data requires accounting for the role of regional groundwater. The widespread occurrence of two key factors (regional interbasin groundwater flow, and elevated dissolved C in regional groundwater) suggests regional groundwater may affect C fluxes and budgets at many sites.

Factors affecting water strider (Hemiptera: Gerridae) mercury concentrations in lotic systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jardine, T.D.; Kidd, K.A.; Cunjak, R.A.

2009-07-15

Water striders (Hemiptera: Gerridae) have been considered as a potential sentinel for mercury (Hg) contamination of freshwater ecosystems, yet little is known about factors that control Hg concentrations in this invertebrate. Striders were collected from 80 streams and rivers in New Brunswick, Canada, in August and September of 2004 through 2007 to assess the influence of factors such as diet, water chemistry, and proximity to point sources on Hg concentrations in this organism. Higher than average Hg concentrations were observed in the southwest and Grand Lake regions of the province, the latter being the location of a coal-fired power plantmore » that is a source of Hg (similar to 100 kg annually), with elevated Hg concentrations in the lichen Old Man's Beard (Usnea spp.) in its immediate vicinity. Across all streams, pH and total organic carbon of water were relatively weak predictors of strider Hg concentrations. Female striders that were larger in body size than males had significantly lower Hg concentrations within sites, suggestive of growth dilution. There was no relationship between percent aquatic carbon in the diet and Hg concentrations in striders. For those striders feeding solely on terrestrial carbon, Hg concentrations were higher in animals occupying a higher trophic level. Mercury concentrations were highly variable in striders collected monthly over two growing seasons, suggesting short-term changes in Hg availability. These measurements highlight the importance of considering both deposition and postdepositional processes in assessing Hg bioaccumulation in this species.« less

Factors regulating nitrification in aquatic sediments: Effects of organic carbon, nitrogen availability, and pH

USGS Publications Warehouse

Strauss, E.A.; Mitchell, N.L.; Lamberti, G.A.

2002-01-01

We investigated the response in nitrification to organic carbon (C) availability, the interactive effects of the C: nitrogen (N) ratio and organic N availability, and differing pH in sediments from several streams in the upper midwestern United States. In addition, we surveyed 36 streams to assess variability in sediment nitrification rates. Labile dissolved organic carbon (DOC) additions of 30 mg C??L-1 (as acetate) to stream sediments reduced nitrification rates (P < 0.003), but lower concentration additions or dilution of ambient DOC concentration had no effect on nitrification. C:N and organic N availability strongly interacted to affect nitrification (P < 0.0001), with N availability increasing nitrification most at lower C:N. Nitrification was also strongly influenced by pH (P < 0.002), with maximum rates occurring at pH 7.5. A multiple regression model developed from the stream survey consisted of five variables (stream temperature, pH, conductivity, DOC concentration, and total extractable NH4+) and explained 60% of the variation observed in nitrification. Our results suggest that nitrification is regulated by several variables, with NH4+ availability and pH being the most important. Organic C is likely important at regulating nitrification only under high environmental C:N conditions and if most available C is relatively labile.

Effects of the H-3 Highway Stormwater Runoff on the Water Quality of Halawa Stream, Oahu, Hawaii, November 1998 to August 2004

USGS Publications Warehouse

Wolff, Reuben H.; Wong, Michael F.

2008-01-01

Since November 1998, water-quality data have been collected from the H-3 Highway Storm Drain C, which collects runoff from a 4-mi-long viaduct, and from Halawa Stream on Oahu, Hawaii. From January 2001 to August 2004, data were collected from the storm drain and four stream sites in the Halawa Stream drainage basin as part of the State of Hawaii Department of Transportation Storm Water Monitoring Program. Data from the stormwater monitoring program have been published in annual reports. This report uses these water-quality data to explore how the highway storm-drain runoff affects Halawa Stream and the factors that might be controlling the water quality in the drainage basin. In general, concentrations of nutrients, total dissolved solids, and total suspended solids were lower in highway runoff from Storm Drain C than at stream sites upstream and downstream of Storm Drain C. The opposite trend was observed for most trace metals, which generally occurred in higher concentrations in the highway runoff from Storm Drain C than in the samples collected from Halawa Stream. The absolute contribution from Storm Drain C highway runoff, in terms of total storm loads, was much smaller than at stations upstream and downstream, whereas the constituent yields (the relative contribution per unit drainage basin area) at Storm Drain C were comparable to or higher than storm yields at stations upstream and downstream. Most constituent concentrations and loads in stormwater runoff increased in a downstream direction. The timing of the storm sampling is an important factor controlling constituent concentrations observed in stormwater runoff samples. Automated point samplers were used to collect grab samples during the period of increasing discharge of the storm throughout the stormflow peak and during the period of decreasing discharge of the storm, whereas manually collected grab samples were generally collected during the later stages near the end of the storm. Grab samples were analyzed to determine concentrations and loads at a particular point in time. Flow-weighted time composite samples from the automated point samplers were analyzed to determine mean constituent concentrations or loads during a storm. Chemical analysis of individual grab samples from the automated point sampler at Storm Drain C demonstrated the ?first flush? phenomenon?higher constituent concentrations at the beginning of runoff events?for the trace metals cadmium, lead, zinc, and copper, whose concentrations were initially high during the period of increasing discharge and gradually decreased over the duration of the storm. Water-quality data from Storm Drain C and four stream sites were compared to the State of Hawaii Department of Health (HDOH) water-quality standards to determine the effects of highway storm runoff on the water quality of Halawa Stream. The geometric-mean standards and the 10- and 2-percent-of-the-time concentration standards for total nitrogen, nitrite plus nitrate, total phosphorus, total suspended solids, and turbidity were exceeded in many of the comparisons. However, these standards were not designed for stormwater sampling, in which constituent concentrations would be expected to increase for short periods of time. With the aim of enhancing the usefulness of the water-quality data, several modifications to the stormwater monitoring program are suggested. These suggestions include (1) the periodic analyzing of discrete samples from the automated point samplers over the course of a storm to get a clearer profile of the storm, from first flush to the end of the receding discharge; (2) adding an analysis of the dissolved fractions of metals to the sampling plan; (3) installation of an automatic sampler at Bridge 8 to enable sampling earlier in the storms; (4) a one-time sampling and analysis of soils upstream of Bridge 8 for base-line contaminant concentrations; (5) collection of samples from Halawa Stream during low-flow conditions

Nitrification in four acidic streams in southern New Jersey

USGS Publications Warehouse

Schornick, James C.; Ram, Neil M.

1978-01-01

Four characteristically acidic streams in southern New Jersey were investigated to determine the effect of secondary effluent on nitrification in the receiving waters. Chemical and microbiological data were obtained at four sites on each stream. From these data seven factors were evaluated to determine the proclivity of each stream to nitrify. pH, water temperature, and dissolved oxygen were used to describe the general condition of the streams, while neutralization of alkalinity, nitrogen species concentration trends, biological and nitrogenous oxygen demand incubations, and nitrifying bacteria densities were used to determine the actual presence of nitrification in each stream. Each stream had a unique distribution of conditions, making it possible to qualitatively rank the streams according to their proclivity to nitrify. Hay StackBrook showes strong evidence for nitrification on the basis of all four nitrification indicators, whereas Landing Creek showed little, if any, evidence of nitrification. Hammonton Creek is apparently nitrifying, but because of the uncertainty in the downstream trends of the nitrogen species and a lower level of alkalinity neutralization, it is nitrifying less than Hay Stack Brook. Squankum Branch also showed some evidence for nitrification, mostly on the basis of the biological and nitrogenous oxygen demand incubations. Although these streams are acidic in character, acidity does not appear to be an exclusive factor in determining whether a stream will undergo nitrification. (Woodard-USGS)

Influence of Environmental Factors on Biotic Responses to Nutrient Enrichment in Agricultural Streams1

PubMed Central

Maret, Terry R; Konrad, Christopher P; Tranmer, Andrew W

2010-01-01

The influence of environmental factors on biotic responses to nutrients was examined in three diverse agricultural regions of the United States. Seventy wadeable sites were selected along an agricultural land use gradient while minimizing natural variation within each region. Nutrients, habitat, algae, macroinvertebrates, and macrophyte cover were sampled during a single summer low-flow period in 2006 or 2007. Continuous stream stage and water temperature were collected at each site for 30 days prior to sampling. Wide ranges of concentrations were found for total nitrogen (TN) (0.07-9.61 mg/l) and total phosphorus (TP) (<0.004-0.361 mg/l), but biotic responses including periphytic and sestonic chlorophyll a (RCHL and SCHL, respectively), and percent of stream bed with aquatic macrophyte (AQM) growth were not strongly related to concentrations of TN or TP. Pearson’s coefficient of determination (R2) for nutrients and biotic measures across all sites ranged from 0.08 to 0.32 and generally were not higher within each region. The biotic measures (RCHL, SCHL, and AQM) were combined in an index to evaluate eutrophic status across sites that could have different biotic responses to nutrient enrichment. Stepwise multiple regression identified TN, percent canopy, median riffle depth, and daily percent change in stage as significant factors for the eutrophic index (R2 = 0.50, p < 0.001). A TN threshold of 0.48 mg/l was identified where eutrophic index scores became less responsive to increasing TN concentrations, for all sites. Multiple plant growth indicators should be used when evaluating eutrophication, especially when streams contain an abundance of macrophytes. PMID:22457568

Complex Catchment Processes that Control Stream Nitrogen and Organic Matter Concentrations in a Northeastern USA Upland Catchment

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Pellerin, B.; Saraceno, J.; Aiken, G. R.; Boyer, E. W.; Doctor, D. H.; Kendall, C.

2009-05-01

There is a need to understand the coupled biogeochemical and hydrological processes that control stream hydrochemistry in upland forested catchments. At watershed 9 (W-9) of the Sleepers River Research Watershed in the northeastern USA, we use high-frequency sampling, environmental tracers, end-member mixing analysis, and stream reach mass balances to understand dynamic factors affect forms and concentrations of nitrogen and organic matter in streamflow. We found that rates of stream nitrate processing changed during autumn baseflow and that up to 70% of nitrate inputs to a stream reach were retained. At the same time, the stream reach was a net source of the dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) fractions of dissolved organic matter (DOM). The in-stream nitrate loss and DOM gains are examples of hot moments of biogeochemical transformations during autumn when deciduous litter fall increases DOM availability. As hydrological flowpaths changed during rainfall events, the sources and transformations of nitrate and DOM differed from baseflow. For example, during storm flow we measured direct inputs of unprocessed atmospheric nitrate to streams that were as large as 30% of the stream nitrate loading. At the same time, stream DOM composition shifted to reflect inputs of reactive organic matter from surficial upland soils. The transport of atmospheric nitrate and reactive DOM to streams underscores the importance of quantifying source variation during short-duration stormflow events. Building upon these findings we present a conceptual model of interacting ecosystem processes that control the flow of water and nutrients to streams in a temperate upland catchment.

Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment

NASA Astrophysics Data System (ADS)

Bernal, Susana; Lupon, Anna; Catalán, Núria; Castelar, Sara; Martí, Eugènia

2018-03-01

Streams are important sources of carbon to the atmosphere, though knowing whether they merely outgas terrestrially derived carbon dioxide or mineralize terrestrial inputs of dissolved organic matter (DOM) is still a big challenge in ecology. The objective of this study was to investigate the influence of riparian groundwater (GW) and in-stream processes on the temporal pattern of stream DOM concentrations and quality in a forested headwater stream, and whether this influence differed between the leaf litter fall (LLF) period and the remaining part of the year (non-LLF). The spectroscopic indexes (fluorescence index, biological index, humification index, and parallel factor analysis components) indicated that DOM had an eminently protein-like character and was most likely originated from microbial sources and recent biological activity in both stream water and riparian GW. However, paired samples of stream water and riparian GW showed that dissolved organic carbon (DOC) and nitrogen (DON) concentrations as well as the spectroscopic character of DOM differed between the two compartments throughout the year. A simple mass balance approach indicated that in-stream processes along the reach contributed to reducing DOC and DON fluxes by 50 and 30 %, respectively. Further, in-stream DOC and DON uptakes were unrelated to each other, suggesting that these two compounds underwent different biogeochemical pathways. During the LLF period, stream DOC and DOC : DON ratios were higher than during the non-LLF period, and spectroscopic indexes suggested a major influence of terrestrial vegetation on stream DOM. Our study highlights that stream DOM is not merely a reflection of riparian GW entering the stream and that headwater streams have the capacity to internally produce, transform, and consume DOM.

Ptaquiloside from bracken in stream water at base flow and during storm events.

PubMed

Clauson-Kaas, Frederik; Ramwell, Carmel; Hansen, Hans Chr B; Strobel, Bjarne W

2016-12-01

The bracken fern (Pteridium spp.) densely populates both open and woodland vegetation types around the globe. Bracken is toxic to livestock when consumed, and a group of potent illudane-type carcinogens have been identified, of which the compound ptaquiloside (PTA) is the most abundant. The highly water soluble PTA has been shown to be leachable from bracken fronds, and present in the soil and water below bracken stands. This has raised concerns over whether the compound might pose a risk to drinking water sources. We investigated PTA concentrations in a small stream draining a bracken-infested catchment at base flow and in response to storm events during a growth season, and included sampling of the bracken canopy throughfall. Streams in other bracken-dominated areas were also sampled at base flow for comparison, and a controlled pulse experiment was conducted in the field to study the in-stream dynamics of PTA. Ptaquiloside concentrations in the stream never exceeded 61 ng L -1 in the base flow samples, but peaked at 2.2 μg L -1 during the studied storm events. The mass of PTA in the stream, per storm event, was 7.5-93 mg from this catchment. A clear temporal connection was observed between rainfall and PTA concentration in the stream, with a reproducible time lag of approx. 1 h from onset of rain to elevated concentrations, and returning rather quickly (about 2 h) to base flow concentration levels. The concentration of PTA behaved similar to an inert tracer (Cl - ) in the pulse experiment over a relative short time scale (minutes-hours) reflecting no PTA sorption, and dispersion and dilution considerably lowered the observed PTA concentrations downstream. Bracken throughfall revealed a potent and lasting source of PTA during rainfall, with concentrations up to 169 μg L -1 , that did not decrease over the course of the event. In the stream, the throughfall contribution to PTA cannot be separated from a possible below-ground input from litter, rhizomes and soil. Catchment-specific factors such as the soil pH, topography, hydrology, and bracken coverage will evidently affect the level of PTA observed in the receiving stream, as well as the distance from bracken, but time since precipitation seems most important. Studying PTA loads and transport in surface streams fed by bracken-infested catchments, simply taking occasional grab samples will not capture the precipitation-linked pulses. The place and time of sampling governs the findings, and including event-based sampling is essential to provide a more complete picture of PTA loads to surface water. Copyright © 2016 Elsevier Ltd. All rights reserved.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Clear Creek, Monroe County, Indiana

USGS Publications Warehouse

Wilber, William G.; Crawford, Charles G.; Peters, J.G.; Girardi, F.P.

1979-01-01

A digital model calibrated to conditions in Clear Creek, Monroe County, IN, was used to develop alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. The Winston Thomas wastewater-treatment facility is the only point-source waste load affecting the modeled reach of Clear Creek. A new waste-water-treatment facility under construction at Dillman Road (river mile 13.78) will replace the Winston Thomas wastewater-treatment facility (river mile 16.96) in 1980. Natural streamflow during the summer and annual 7-day, 10-year low flow is zero, so no benefit from dilution is provided. The model indicates that ammonia-nitrogen toxicity is the most significant factor affecting the stream water quality during summer and winter low flows. The ammonia-nitrogen concentration of the wastewater effluent exceeds the maximum total ammonia-nitrogen concentration of 2.5 milligrams per liter for summer months (June through August) and 4.0 milligrams per liter for winter months (November through March) required for Indiana streams. Nitrification, benthic-oxygen demand, and algal respiration were the most significant factors affecting the dissolved-oxygen concentration in Clear Creek during the model calibration. Nitrification should not significantly affect the dissolved-oxygen concentration in Clear Creek during summer low flows when the ammonia-nitrogen toxicity standards are met. (USGS)

Geohydrology and water quality of Kalamazoo County, Michigan, 1986-88

USGS Publications Warehouse

Rheaume, S.J.

1990-01-01

Thick, glacial sand and gravel deposits provide most ground-water supplies in Kalamazoo County. These deposits range in thickness from 50 to about 600 feet in areas that overlie buried bedrock valleys. Most domestic wells completed at depths of less than 75 feet in the sands and gravels yield adequate water supplies. Most industry, public supply, and irrigation wells completed at depths of 100 to 200 feet yield 1,000 gallons per minute or more. The outwash plains include the most productive of the glacial aquifers in the county. The Coldwater Shale of Mississippian age, which underlies the glacial deposits in most of the county, usually yields only small amounts of largely mineralized water. Ground-water levels in Kalamazoo County reflect short- and long-term changes in precipitation and local pumpage. Ground-water levels increase in the spring and decline in the fall. Ground-water recharge rates, for different geologic settings, were estimated from ground-water runoff to the streams. Recharge rates ranged from 10.86 to 5.87 inches per year. A countywide-average ground-water recharge rate is estimated to be 9.32 inches per year. Chemical quality of precipitation and dry fallout at two locations in Kalamazoo County were similar to that of other areas in the State. Total deposition of dissolved sulfate is 30.7 pounds per acre per year, of total nitrogen is 13.2 pounds per acre per year, and of total phosphorus is 0.3 pounds per acre per year. Rainfall and snow data indicated that the pH of precipitation is inversely proportional to its specific conductance. Water of streams and rivers of Kalamazoo County is predominately of the calcium bicarbonate type, although dissolved sulfate concentrations are slightly larger in streams in the southeastern and northwestern parts of the county. The water in most streams is hard to very hard. Concentrations of dissolved chloride in streams draining urban-industrial areas are slightly larger than at other locations. Concentrations of total nitrogen and total phosphorus in streams are directly proportional to streamflow. Except for elevated concentrations of iron, none of the trace elements in streams exceeded maximum contaminant levels for drinking water established by the U.S. Environmental Protection Agency. Pesticides were detected in some streams. Ground water in the surficial aquifers is of the calcium bicarbonate type, although sodium, sulfate, and chloride ions predominate at some locations. Specific conductance and hardness and concentrations of total dissolved-solids slightly exceed statewide averages. Concentrations of dissolved sodium and dissolved chloride in 6 wells were greater than most natural ground waters in the State, indicating possible contamination from road salts. Water samples from 6 of the 46 wells sampled contained concentrations of total nitrate as nitrogen greater than 10.0 milligrams per liter. Elevated concentrations of total nitrate as nitrogen in water from wells in rural-agricultural areas probably are related to fertilizer applications. Results of partial chemical analyses by the Michigan Department of Public Health indicates specific conductance, and concentrations of hardness, dissolved fluoride, and total iron are fairly uniform throughout the county. Concentrations of dissolved sodium, dissolved chloride, and total nitrate as nitrogen differed among townships. Pesticides were detected in water from only one well. Water from five wells contained volatile organics. A map of susceptibility of ground water to contamination in Kalamazoo County was developed using a system created by the U.S. Environmental Protection Agency. Seven geohydrologic factors that affect and control ground-water movement are mapped and composited onto a countywide map. All seven factors have some effect on countywide susceptibility, but the most important factors are depth to water and composition of the materials above the aquifer.

River-groundwater connectivity and nutrient dynamics in a mesoscale catchment

NASA Astrophysics Data System (ADS)

Fleckenstein, Jan H.; Musolff, Andreas; Gilfedder, Benjamin; Frei, Sven; Wankmüller, Fabian; Trauth, Nico

2017-04-01

Diffuse solute exports from catchments are governed by many interrelated factors such as land use, climate, geological-/ hydrogeological setup and morphology. Those factors create spatial variations in solute concentrations and turnover rates in the subsurface as well as in the stream network. River-groundwater connectivity is a crucial control in this context: On the one hand groundwater is a main pathway for nitrate inputs to the stream. On the other hand, groundwater connectivity with the stream affects the magnitude of hyporheic exchange of stream water with the stream bed. We present results of a longitudinal sampling campaign along the Selke river, a 67 km long third-order stream in the Harz mountains in central Germany. Water quality at the catchment outlet is strongly impacted by agriculture with high concentrations of nitrate and a chemostatic nitrate export regime. However, the specific nitrate pathways to the stream are not fully understood as there is arable land distributed throughout the catchment. While the sparsely distributed arable land in the mountainous upper catchment receives much higher amounts of precipitation, the downstream alluvial plains are drier, but more intensively used. The three-day campaign was conducted in June 2016 under constant low flow conditions. Stream water samples were taken every 2 km along the main stem of the river and at its major tributaries. Samples were analyzed for field parameters, major cations and anions, N-O isotopes, nutrients and Radon-222 (Rn) concentrations. Additionally, at each sampling location, river discharge was manually measured using current meters. Groundwater influxes to each sampled river section were quantified from the Rn measurements using the code FINIFLUX, (Frei and Gilfedder 2015). Rn and ion concentrations showed an increase from the spring to the mouth, indicating a growing impact of groundwater flux to the river. However, increases in groundwater gains were not gradual. The strongest gains were observed downstream of where the Selke River leaves the Harz Mountains and enters the alluvial plains. At this location, land use, hydrogeological setup and river slope as well as average slope of the contributing catchment area change significantly. Downstream of this point 15N isotope values were also significantly higher, suggesting higher denitrification activity in the deeper aquifers of lower catchment. While specific discharge (discharge per catchment area) was 3 times higher in the upper catchment, nitrate mass flux per area was more than 3 times higher in lower catchment compared to the respective other part of the catchment. We conclude that catchment morphology, (hydro)geology and hydrology control river-groundwater connectivity while the interplay with land use controls in stream nitrate concentrations. Repeated sampling campaigns will allow assessing seasonal changes in solute inputs and turnover. References Frei, S. & Gilfedder, B.S. (2015): FINIFLUX: An implicit finite element model for quantification of groundwater fluxes and hyporheic exchange in streams and rivers using radon. Water Resources Research, DOI: 10.1002/2015WR017212.

Stream Dissolved Organic Matter Quantity and Quality Along a Wetland-Cropland Catchment Gradient

NASA Astrophysics Data System (ADS)

McDonough, O.; Hosen, J. D.; Lang, M. W.; Oesterling, R.; Palmer, M.

2012-12-01

Wetlands may be critical sources of dissolved organic matter (DOM) to stream networks. Yet, more than half of wetlands in the continental United States have been lost since European settlement, with the majority of loss attributed to agriculture. The degree to which agricultural loss of wetlands impacts stream DOM is largely unknown and may have important ecological implications. Using twenty headwater catchments on the Delmarva Peninsula (Maryland, USA), we investigated the seasonal influence of wetland and cropland coverage on downstream DOM quantity and quality. In addition to quantifying bulk downstream dissolved organic carbon (DOC) concentration, we used a suite of DOM UV-absorbance metrics and parallel factor analysis (PARAFAC) modeling of excitation-emission fluorescence spectra (EEMs) to characterize DOM composition. Percent bioavailable DOC (%BDOC) was measured during the Spring sampling using a 28-day incubation. Percent wetland coverage and % cropland within the watersheds were significantly negatively correlated (r = -0.93, p < 0.001). Results show that % wetland coverage was positively correlated with stream DOM concentration, molecular weight, aromaticity, humic-like fluorescence, and allochthonous origin. Conversely, increased wetland coverage was negatively correlated with stream DOM protein-like fluorescence. Percent BDOC decreased with DOM humic-like fluorescence and increased with protein-like fluorescence. We observed minimal seasonal interaction between % wetland coverage and DOM concentration and composition across Spring, Fall, and Winter sampling seasons. However, principal component analysis suggested more pronounced seasonal differences exist in stream DOM. This study highlights the influence of wetlands on downstream DOM in agriculturally impacted landscapes where loss of wetlands to cultivation may significantly alter stream DOM quantity and quality.

Water-quality characteristics for selected streams in Lawrence County, South Dakota, 1988-92

USGS Publications Warehouse

Williamson, Joyce E.; Hayes, Timothy Scott

2000-01-01

During the 1980?s, significant economic development and population growth began to occur in Lawrence County in the northern part of the Black Hills of western South Dakota. Rising gold prices and heap-leach extraction methods allowed the economic recovery of marginal gold ore deposits, resulting in development of several large-scale, open-pit gold mines in Lawrence County. There was increasing local concern regarding potential impacts on the hydrologic system, especially relating to the quantity and quality of water in the numerous streams and springs of Lawrence County. In order to characterize the water quality of selected streams within Lawrence County, samples were collected from 1988 through 1992 at different times of the year and under variable hydrologic conditions. During the time of this study, the Black Hills area was experiencing a drought; thus, most samples were collected during low-flow conditions.Streamflow and water-quality characteristics in Lawrence County are affected by both geologic conditions and precipitation patterns. Most streams that cross outcrops of the Madison Limestone and Minnelusa Formation lose all or large part of their streamflow to aquifer recharge. Streams that are predominantly spring fed have relatively stable streamflow, varying slightly with dry and wet precipitation cycles.Most streams in Lawrence County generally have calcium magnesium bicarbonate type waters. The sites from the mineralized area of central Lawrence County vary slightly from other streams in Lawrence County by having higher concentrations of sodium, less bicarbonate, and more sulfate. False Bottom Creek near Central City has more sulfate than bicarbonate. Nitrogen, phosphorous, and cyanide concentrations were at or near the laboratory reporting limits for most sites and did not exceed any of the water-quality standards. Nitrite plus nitrate concentrations at Annie Creek near Lead, Whitetail Creek at Lead, Squaw Creek near Spearfish, and Spearfish Creek below Robison Gulch were somewhat higher than at other sites. Mining activity, agricultural activity, and domestic development are possible sources of nitrogen to the streams. Increased mining activities were identified as the probable cause of increased nitrogen concentrations in Annie Creek.In the mineralized area of the northern Black Hills, detectable concentrations of trace elements are common in stream water, occasionally exceeding beneficial-use and aquatic-life criteria. In addition, many basins have been disturbed by both historical and recent mining operations and cleanup activities. The maximum dissolved arsenic concentration at Annie Creek near Lead (48 micrograms per liter) approached the current arsenic drinking-water standard. Concentrations at or greater than 5 micrograms per liter were found in samples from Annie Creek near Lead, Spearfish Creek above Spearfish, Whitetail Creek at Lead, and False Bottom Creek near Spearfish. Bear Butte Creek near Deadwood had one sample with a dissolved copper concentration that exceeded acute and chronic aquatic-life criteria. Bear Butte Creek near Deadwood had several manganese concentrations that exceeded the secondary maximum contaminant level of 50 micrograms per liter.Bed-sediment and water-quality data from selected sites in small drainage basins were used to determine if factors such as pH, arsenic concentrations in bed sediments, and calcite saturation control dissolved arsenic concentrations. Arsenic solubility is controlled by adsorption, mainly on ferrihydrite. In addition, adsorption/desorption of arsenic is controlled by the pH of the stream, with high arsenic concentrations appearing only at higher pH conditions (above 8). There are significant arsenic sources available to almost all the small streams of the northern Black Hills mining area, but arsenic is less mobile in streams that are not influenced to the higher pH values by calcite. Streams where arsenic is more mobile have lower iron concentrations i

Assessment of water chemistry, habitat, and benthic macroinvertebrates at selected stream-quality monitoring sites in Chester County, Pennsylvania, 1998-2000

USGS Publications Warehouse

Reif, Andrew G.

2004-01-01

Biological, chemical, and habitat data have been collected from a network of sites in Chester County, Pa., from 1970 to 2003 to assess stream quality. Forty sites in 6 major stream basins were sampled between 1998 and 2000. Biological data were used to determine levels of impairment in the benthic-macroinvertebrate community in Chester County streams and relate the impairment, in conjunction with chemical and habitat data, to overall stream quality. Biological data consisted of benthic-macroinvertebrate samples that were collected annually in the fall. Water-chemistry samples were collected and instream habitat was assessed in support of the biological sampling.Most sites in the network were designated as nonimpacted or slightly impacted by human activities or extreme climatic conditions on the basis of biological-metric analysis of benthic-macroinvertebrate data. Impacted sites were affected by factors, such as nutrient enrichment, erosion and sedimentation, point discharges, and droughts and floods. Streams in the Schuylkill River, Delaware River, and East Branch Brandywine Creek Basins in Chester County generally had low nutrient concentrations, except in areas affected by wastewater-treatment discharges, and stream habitat that was affected by erosion. Streams in the West Branch Brandywine, Christina, Big Elk, and Octoraro Creek Basins in Chester County generally had elevated nutrient concentrations and streambottom habitat that was affected by sediment deposition.Macroinvertebrate communities identified in samples from French Creek, Pigeon Creek (Schuylkill River Basin), and East Branch Brandywine Creek at Glenmoore consistently indicate good stream conditions and were the best conditions measured in the network. Macroinvertebrate communities identified in samples from Trout Creek (site 61), West Branch Red Clay Creek (site 55) (Christina River Basin), and Valley Creek near Atglen (site 34) (Octoraro Creek Basin) indicated fair to poor stream conditions and were the worst conditions measured in the network. Trout Creek is heavily impacted due to erosion, and Valley Creek near Atglen and West Branch Red Clay Creek are influenced by wastewater discharges. Hydrologic conditions in 1999, including a prolonged drought and a flood, influenced chemical concentrations and macroinvertebrate community structure throughout the county. Concentrations of nutrients and ions were lower in 1999 when compared to 1998 and 2000 concentrations. Macroinvertebrate communities identified in samples from 1999 contained lower numbers of individuals when compared to 1998 and 2000 but had similar community structure. Results from chemical and biological sampling in 2000 indicated that the benthic-macroinvertebrate community structure and the concentrations of nutrients and ions recovered to pre-1999 levels.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Wabash River, Huntington County, Indiana

USGS Publications Warehouse

Crawford, Charles G.; Wilber, William G.; Peters, James G.

1980-01-01

A digital model calibrated to conditions in the Wabash River in Huntington County, Ind., was used to predict alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditons, summer and winter low flows. The major point-source waste load affecting the Wabash River in Huntington County is the Huntington wastewater-treatment facility. The most significnt factor potentially affecting the dissolved-oxygen concentration during summer low flows is nitrification. However, nitrification should not be a limiting factor on the allowable nitrogenous and carbonaceous waste loads for the Huntington wastewater-treatment facility during summer low flows if the ammonia-nitrogen toxicity standard for Indiana streams is met. The disolved-oxygen standard for Indiana stream, an average of 5.0 milligrams per liter, should be met during summer and winter low flows if the National Pollution Discharge Elimination System 's 5-day, carbonaceous biochemical-oxygen demands of a monthly average concentration of 30 milligrams per liter and a maximum weekly average of 45 milligrams per liter are not exceeded. 

Hydrogeochemical and stream sediment reconnaissance basic data for Waco NTMS quadrangle, Texas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1981-07-31

Results of a reconnaissance geochemical survey of the Waco Quadrangle are reported. Field and laboratory data are presented for 218 groundwater and 614 stream sediment samples. Statistical and areal distribution of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwater data indicate that uranium concentrations above the 85th percentile occur primarily in the Upper cretaceous units (Navarro, Taylor, and Woodbine Groups) and Lower Cretaceous carbonate units (Fredricksburg and Wilcox Groups). Saline watermore » trends are also prominent in these units. Stream sediment data indicate high uranium concentrations occur in the western portion of the quadrangle. Most of the samples with high uranium values are collected from the Upper and Lower Cretaceous and Tertiary units. Associated with the high uranium values are high concentrations of aluminum, chromium, iron, scandium, yttrium, zinc, and zirconium.« less

Bioavailability of metals in stream food webs and hazards to brook trout (Salvelinus fontinalis) in the upper Animas River watershed, Colorado

USGS Publications Warehouse

Besser, J.M.; Brumbaugh, W.G.; May, T.W.; Church, S.E.; Kimball, B.A.

2001-01-01

The water quality, habitats, and biota of streams in the upper Animas River watershed of Colorado, USA, are affected by metal contamination associated with acid drainage. We determined metal concentrations in components of the food web of the Animas River and its tributaries - periphyton (aufwuchs), benthic invertebrates, and livers of brook trout (Salvelinus fontinalis) - and evaluated pathways of metal exposure and hazards of metal toxicity to stream biota. Concentrations of the toxic metals cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in periphyton, benthic invertebrates, and trout livers from one or more sites in the upper Animas River were significantly greater than those from reference sites. Periphyton from sites downstream from mixing zones of acid and neutral waters had elevated concentrations of aluminum (Al) and iron (Fe) reflecting deposition of colloidal Fe and Al oxides, and reduced algal biomass. Metal concentrations in benthic invertebrates reflected differences in feeding habits and body size among taxa, with greatest concentrations of Zn, Cu, and Cd in the small mayfly Rhithrogena, which feeds on periphyton, and greatest concentrations of Pb in the small stonefly Zapada, a detritivore. Concentrations of Zn and Pb decreased across each trophic linkage, whereas concentrations of Cu and Cd were similar across several trophic levels, suggesting that Cu and Cd were more efficiently transferred via dietary exposure. Concentrations of Cu in invertebrates and trout livers were more closely associated with impacts on trout populations and invertebrate communities than were concentrations of Zn, Cd, or Pb. Copper concentrations in livers of brook trout from the upper Animas River were substantially greater than background concentrations and approached levels associated with reduced brook trout populations in field studies and with toxic effects on other salmonids in laboratory studies. These results indicate that bioaccumulation and transfer of metals in stream food webs are significant components of metal exposure for stream biota of the upper Animas River watershed and suggest that chronic toxicity of Cu is an important factor limiting the distribution and abundance of brook trout populations in the watershed.

Watershed regressions for pesticides (warp) models for predicting atrazine concentrations in Corn Belt streams

USGS Publications Warehouse

Stone, Wesley W.; Gilliom, Robert J.

2012-01-01

Watershed Regressions for Pesticides (WARP) models, previously developed for atrazine at the national scale, are improved for application to the United States (U.S.) Corn Belt region by developing region-specific models that include watershed characteristics that are influential in predicting atrazine concentration statistics within the Corn Belt. WARP models for the Corn Belt (WARP-CB) were developed for annual maximum moving-average (14-, 21-, 30-, 60-, and 90-day durations) and annual 95th-percentile atrazine concentrations in streams of the Corn Belt region. The WARP-CB models accounted for 53 to 62% of the variability in the various concentration statistics among the model-development sites. Model predictions were within a factor of 5 of the observed concentration statistic for over 90% of the model-development sites. The WARP-CB residuals and uncertainty are lower than those of the National WARP model for the same sites. Although atrazine-use intensity is the most important explanatory variable in the National WARP models, it is not a significant variable in the WARP-CB models. The WARP-CB models provide improved predictions for Corn Belt streams draining watersheds with atrazine-use intensities of 17 kg/km2 of watershed area or greater.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruffey, Stephanie H.; Jubin, Robert Thomas

U.S. regulations will require the removal of 129I from the off-gas streams of any used nuclear fuel (UNF) reprocessing plant prior to discharge of the off-gas to the environment. The required plant decontamination factor for iodine will vary based on fuel burnup, cooling time, and other factors but is very likely to be >1000 and could be as high as 8000. Multiple off-gas streams within a UNF reprocessing plant combine prior to environmental release, and each of these streams contains some amount of iodine. To achieve the decontamination factors (DFs) that are likely to be required by regulations, iodine removalmore » from the vessel off-gas will be necessary. The vessel off-gas contains iodine at very dilute concentrations (ppb levels), and will also contain water vapor. Iodine species present are likely to include both elemental and organic iodides. There will also be solvent vapors and volatile radiolysis products. The United States has considered the use of silver-based sorbents for removal of iodine from UNF off-gas streams, but little is known about the behavior of those sorbents at very dilute iodine concentrations. The purpose of this study was to expose silver-functionalized silica aerogel (AgAerogel) to a prototypical vessel off-gas stream containing 40 ppb methyl iodide to obtain information about organic iodine capture by silver-sorbents at very low iodine concentrations. The design of this extended duration testing was such that information about the rate of adsorption, the penetration of the iodine species, and the overall system DF could be obtained. Results show that CH 3I penetrates into a AgAerogel sorbent bed to a depth of 3.9 cm under prototypical vessel off-gas conditions. An iodine loading of 22 mg I/g AgAerogel was observed in the first 0.3 cm of the bed. Of the iodine delivered to the system, 48% could not be accounted for, and future efforts will investigate this concern. Direct calculation of the decontamination factor is not possible, as no iodine was observed to break through the sorbent beds. Continued studies on the adsorption of iodine from prototypical vessel off-gas streams by silver-based sorbents will attempt to resolve some of the questions raised here, both regarding mass balance and the effect of aging on iodine adsorption by AgAerogel from a dilute gas stream. Additionally, the adsorption of different iodine species, such as I 2 and C 12H 25I will be studied. Other variables that merit examination are the gas velocity of the test and the dependence of the observed results on the inlet iodine concentration. Finally, longer duration testing should be considered in an effort to determine the mass transfer zone associated with iodine adsorption by AgAerogel under prototypical vessel off-gas conditions. The estimation of mass transfer zone is required for any future industrial implementation.« less

Ecological health in the Nation's streams

USGS Publications Warehouse

Carlisle, Daren M.; Woodside, Michael D.

2013-01-01

Aquatic biological communities, which are collections of organisms, are a direct measure of stream health because they indicate the ability of a stream to support life. This fact sheet highlights selected findings of a national assessment of stream health by the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). The assessment was unique in that it integrated the condition of three biological communities—algae, macroinvertebrates, and fish—as well as measures of streamflow modification, pesticides, nutrients, and other factors. At least one biological community was altered at 83 percent of assessed streams, and the occurrence of altered communities was highest in urban streams. Streamflows were modified at 86 percent of assessed streams, and increasing severity of streamflow modification was associated with increased occurrence of altered biological communities. Agricultural and urban land use in watersheds may contribute pesticides and nutrients to stream waters, and increasing concentrations of these chemicals were associated with increased occurrence of altered biological communities.

Assessing element distribution and speciation in a stream at abandoned Pb-Zn mining site by combining classical, in-situ DGT and modelling approaches.

PubMed

Omanović, Dario; Pižeta, Ivanka; Vukosav, Petra; Kovács, Elza; Frančišković-Bilinski, Stanislav; Tamás, János

2015-04-01

The distribution and speciation of elements along a stream subjected to neutralised acid mine drainage (NAMD) effluent waters (Mátra Mountain, Hungary; Toka stream) were studied by a multi-methodological approach: dissolved and particulate fractions of elements were determined by HR-ICPMS, whereas speciation was carried out by DGT, supported by speciation modelling performed by Visual MINTEQ. Before the NAMD discharge, the Toka is considered as a pristine stream, with averages of dissolved concentrations of elements lower than world averages. A considerable increase of element concentrations caused by effluent water inflow is followed by a sharp or gradual concentration decrease. A large difference between total and dissolved concentrations was found for Fe, Al, Pb, Cu, Zn and As in effluent water and at the first downstream site, with high correlation factors between elements in particulate fraction, indicating their common behaviour, governed by the formation of ferri(hydr)oxides (co)precipitates. In-situ speciation by the DGT technique revealed that Zn, Cd, Ni, Co, Mn and U were predominantly present as a labile, potentially bioavailable fraction (>90%). The formation of strong complexes with dissolved organic matter (DOM) resulted in a relatively low DGT-labile concentration of Cu (42%), while low DGT-labile concentrations of Fe (5%) and Pb (12%) were presumably caused by their existence in colloidal (particulate) fraction which is not accessible to DGT. Except for Fe and Pb, a very good agreement between DGT-labile concentrations and those predicted by the applied speciation model was obtained, with an average correlation factor of 0.96. This study showed that the in-situ DGT technique in combination with model-predicted speciation and classical analysis of samples could provide a reasonable set of data for the assessment of the water quality status (WQS), as well as for the more general study of overall behaviour of the elements in natural waters subjected to high element loads. Copyright © 2014 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Qichun; Zhang, Xuesong; Xu, Xingya

Riverine carbon cycling is an important, but insufficiently investigated component of the global carbon cycle. Analyses of environmental controls on riverine carbon cycling are critical for improved understanding of mechanisms regulating carbon processing and storage along the terrestrial-aquatic continuum. Here, we compile and analyze riverine dissolved organic carbon (DOC) concentration data from 1402 United States Geological Survey (USGS) gauge stations to examine the spatial variability and environmental controls of DOC concentrations in the United States (U.S.) surface waters. DOC concentrations exhibit high spatial variability, with an average of 6.42 ± 6.47 mg C/ L (Mean ± Standard Deviation). In general,more » high DOC concentrations occur in the Upper Mississippi River basin and the Southeastern U.S., while low concentrations are mainly distributed in the Western U.S. Single-factor analysis indicates that slope of drainage areas, wetlands, forests, percentage of first-order streams, and instream nutrients (such as nitrogen and phosphorus) pronouncedly influence DOC concentrations, but the explanatory power of each bivariate model is lower than 35%. Analyses based on the general multi-linear regression models suggest DOC concentrations are jointly impacted by multiple factors. Soil properties mainly show positive correlations with DOC concentrations; forest and shrub lands have positive correlations with DOC concentrations, but urban area and croplands demonstrate negative impacts; total instream phosphorus and dam density correlate positively with DOC concentrations. Notably, the relative importance of these environmental controls varies substantially across major U.S. water resource regions. In addition, DOC concentrations and environmental controls also show significant variability from small streams to large rivers, which may be caused by changing carbon sources and removal rates by river orders. In sum, our results reveal that general multi-linear regression analysis of twenty one terrestrial and aquatic environmental factors can partially explain (56%) the DOC concentration variation. In conclusion, this study highlights the complexity of the interactions among these environmental factors in determining DOC concentrations, thus calls for processes-based, non-linear methodologies to constrain uncertainties in riverine DOC cycling.« less

Biomonitoring of lead, zinc, and cadmium in streams draining lead-mining and non-mining areas, Southeast Missouri, USA

USGS Publications Warehouse

Besser, John M.; Brumbaugh, William G.; May, Thomas W.; Schmitt, Christopher J.

2007-01-01

We evaluated exposure of aquatic biota to lead (Pb), zinc (Zn), and cadmium (Cd) in streams draining a Pb-mining district in southeast Missouri. Samples of plant biomass (detritus, periphyton, and filamentous algae), invertebrates (snails, crayfish, and riffle benthos), and two taxa of fish were collected from seven sites closest to mining areas (mining sites), four sites further downstream from mining (downstream sites), and eight reference sites in fall 2001. Samples of plant biomass from mining sites had highest metal concentrations, with means 10- to 60-times greater than those for reference sites. Mean metal concentrations in over 90% of samples of plant biomass from mining sites were significantly greater than those from reference sites. Mean concentrations of Pb, Zn, and Cd in most invertebrate samples from mining sites, and mean Pb concentrations in most fish samples from mining sites, were also significantly greater than those from reference sites. Concentrations of all three metals were lower in samples from downstream sites, but several samples of plant biomass from downstream sites had metal concentrations significantly greater than those from reference sites. Analysis of supplemental samples collected in the fall of 2002, a year of above-average stream discharge, had lower Pb concentrations and higher Cd concentrations than samples collected in 2001, near the end of a multi-year drought. Concentrations of Pb measured in fish and invertebrates collected from mining sites during 2001 and 2002 were similar to those measured at nearby sites in the 1970s, during the early years of mining in the Viburnum Trend. Results of this study demonstrate that long-term Pb mining activity in southeast Missouri has resulted in significantly elevated concentrations of Pb, Cd, and Zn in biota of receiving streams, compared to biota of similar streams without direct influence of mining. Our results also demonstrate that metal exposure in the study area differed significantly among sample types, habitats, and years, and that these factors should be carefully considered in the design of biomonitoring studies.

Biomonitoring of lead, zinc, and cadmium in streams draining lead-mining and non-mining areas, Southeast Missouri, USA

USGS Publications Warehouse

Besser, J.M.; Brumbaugh, W.G.; May, T.W.; Schmitt, C.J.

2007-01-01

We evaluated exposure of aquatic biota to lead (Pb), zinc (Zn), and cadmium (Cd) in streams draining a Pb-mining district in southeast Missouri. Samples of plant biomass (detritus, periphyton, and filamentous algae), invertebrates (snails, crayfish, and riffle benthos), and two taxa of fish were collected from seven sites closest to mining areas (mining sites), four sites further downstream from mining (downstream sites), and eight reference sites in fall 2001. Samples of plant biomass from mining sites had highest metal concentrations, with means 10- to 60-times greater than those for reference sites. Mean metal concentrations in over 90% of samples of plant biomass from mining sites were significantly greater than those from reference sites. Mean concentrations of Pb, Zn, and Cd in most invertebrate samples from mining sites, and mean Pb concentrations in most fish samples from mining sites, were also significantly greater than those from reference sites. Concentrations of all three metals were lower in samples from downstream sites, but several samples of plant biomass from downstream sites had metal concentrations significantly greater than those from reference sites. Analysis of supplemental samples collected in the fall of 2002, a year of above-average stream discharge, had lower Pb concentrations and higher Cd concentrations than samples collected in 2001, near the end of a multi-year drought. Concentrations of Pb measured in fish and invertebrates collected from mining sites during 2001 and 2002 were similar to those measured at nearby sites in the 1970s, during the early years of mining in the Viburnum Trend. Results of this study demonstrate that long-term Pb mining activity in southeast Missouri has resulted in significantly elevated concentrations of Pb, Cd, and Zn in biota of receiving streams, compared to biota of similar streams without direct influence of mining. Our results also demonstrate that metal exposure in the study area differed significantly among sample types, habitats, and years, and that these factors should be carefully considered in the design of biomonitoring studies. ?? Springer Science+Business Media B.V. 2006.

Occurrence and in-stream attenuation of wastewater-derived pharmaceuticals in Iberian rivers.

PubMed

Acuña, Vicenç; von Schiller, Daniel; García-Galán, Maria Jesús; Rodríguez-Mozaz, Sara; Corominas, Lluís; Petrovic, Mira; Poch, Manel; Barceló, Damià; Sabater, Sergi

2015-01-15

A multitude of pharmaceuticals enter surface waters via discharges of wastewater treatment plants (WWTPs), and many raise environmental and health concerns. Chemical fate models predict their concentrations using estimates of mass loading, dilution and in-stream attenuation. However, current comprehension of the attenuation rates remains a limiting factor for predictive models. We assessed in-stream attenuation of 75 pharmaceuticals in 4 river segments, aiming to characterize in-stream attenuation variability among different pharmaceutical compounds, as well as among river segments differing in environmental conditions. Our study revealed that in-stream attenuation was highly variable among pharmaceuticals and river segments and that none of the considered pharmaceutical physicochemical and molecular properties proved to be relevant in determining the mean attenuation rates. Instead, the octanol-water partition coefficient (Kow) influenced the variability of rates among river segments, likely due to its effect on sorption to sediments and suspended particles, and therefore influencing the balance between the different attenuation mechanisms (biotransformation, photolysis, sorption, and volatilization). The magnitude of the measured attenuation rates urges scientists to consider them as important as dilution when aiming to predict concentrations in freshwater ecosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

Nutrient and Suspended-Sediment Trends in the Missouri River Basin, 1993-2003

USGS Publications Warehouse

Sprague, Lori A.; Clark, Melanie L.; Rus, David L.; Zelt, Ronald B.; Flynn, Jennifer L.; Davis, Jerri V.

2007-01-01

Trends in streamflow and concentration of total nitrogen, nitrite plus nitrate, ammonia, total phosphorus, orthophosphorus, and suspended sediment were determined for the period from 1993 to 2003 at selected stream sites in the Missouri River Basin. Flow-adjusted trends in concentration (the trends that would have occurred in the absence of natural changes in streamflow) and non-flow-adjusted trends in concentration (the overall trends resulting from natural and human factors) were determined. In the analysis of flow-adjusted trends, the removal of streamflow as a variable affecting concentration allowed trends caused by other factors such as implementation of best management practices to be identified. In the analysis of non-flow-adjusted trends, the inclusion of any and all factors affecting concentration allowed trends affecting aquatic ecosystems and the status of streams relative to water-quality standards to be identified. Relations between the flow-adjusted and non-flow-adjusted trends and changes in streamflow, nutrient sources, ground-water inputs, and implementation of management practices also were examined to determine the major factors affecting the trends. From 1993 to 2003, widespread downward trends in streamflow indicated that drought conditions from about 2000 to 2003 led to decreasing streamflow throughout much of the Missouri River Basin. Flow-adjusted trends in nitrite plus nitrate and ammonia concentrations were split nearly equally between nonsignificant and downward; at about one-half of the sites, management practices likely were contributing to measurable decreases in concentrations of nitrite plus nitrate and ammonia. Management practices had less of an effect on concentrations of total nitrogen; downward flow-adjusted trends in total nitrogen concentrations occurred at only 2 of 19 sites. The pattern of non-flow-adjusted trends in nitrite plus nitrate concentrations was similar to the pattern of flow-adjusted trends; non-flow-adjusted trends were split nearly equally between nonsignificant and downward. A substantial source of nitrite plus nitrate to these streams likely was ground water; because of the time required for ground water to travel to streams, there may have been a lag time between the implementation of some pollution-control strategies and improvement in stream quality, contributing to the nonsignificant trends in nitrite plus nitrate. There were more sites with downward non-flow-adjusted trends than flow-adjusted trends in both ammonia and total nitrogen concentrations, possibly a result of decreased surface runoff from nonpoint sources associated with the downward trends in streamflow. No strong relations between any of the nitrogen trends and changes in nutrient sources or landscape characteristics were identified. Although there were very few upward trends in nitrogen from 1993 to 2003, there were upward flow-adjusted trends in total phosphorus concentrations at nearly one-half of the sites. At these sites, not only were pollution-control strategies not contributing to measurable decreases in total phosphorus concentrations, there was likely an increase in phosphorus loading on the land surface. There were fewer upward non-flow-adjusted than flow-adjusted trends in total phosphorus concentrations; at the majority of sites, overall total phosphorus concentrations did not change significantly during this period. The preponderance of upward flow-adjusted trends and nonsignificant non-flow-adjusted trends indicates that in some areas of the Missouri River Basin, overall concentrations of total phosphorus would have been higher without the decrease in streamflow and the associated decrease in surface runoff during the study period. During the study period, phosphorus loads from fertilizer generally increased at over one-half of the sites in the basin. Upward flow-adjusted trends were related to increasing fertilizer use in the upstream drainage area, particularly in the 10 percent

Soil calcium status and the response of stream chemistry to changing acidic deposition rates

USGS Publications Warehouse

Lawrence, G.B.; David, M.B.; Lovett, Gary M.; Murdoch, Peter S.; Burns, Douglas A.; Stoddard, J.L.; Baldigo, Barry P.; Porter, J.H.; Thompson, A.W.

1999-01-01

Despite a decreasing trend in acidic deposition rates over the past two to three decades, acidified surface waters in the northeastern United States have shown minimal changes. Depletion of soil Ca pools has been suggested as a cause, although changes in soil Ca pools have not been directly related to long-term records of stream chemistry. To investigate this problem, a comprehensive watershed study was conducted in the Neversink River Basin, in the Catskill Mountains of New York, during 1991-1996. Spatial variations of atmospheric deposition, soil chemistry, and stream chemistry were evaluated over an elevation range of 817-1234 m to determine whether these factors exhibited elevational patterns. An increase in atmospheric deposition of SO4 with increasing elevation corresponded with upslope decreases of exchangeable soil base concentrations and acid-neutralizing capacity of stream water. Exchangeable base concentrations in homogeneous soil incubated within the soil profile for one year also decreased with increasing elevation. An elevational gradient in precipitation was not observed, and effects of a temperature gradient on soil properties were not detected. Laboratory leaching experiments with soils from this watershed showed that (1) concentrations of Ca in leachate increased as the concentrations of acid anions in added solution increased, and (2) the slope of this relationship was positively correlated with base saturation. Field and laboratory soil analyses are consistent with the interpretation that decreasing trends in acid-neutralizing capacity in stream water in the Neversink Basin, dating back to 1984, are the result of decreases in soil base saturation caused by acidic deposition.

Hydrogeochemical and stream sediment reconnaissance basic data for Palestine NTMS Quadrangle, Texas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-05-04

Results of a reconnaissance geochemical survey of the Palestine Quadrangle are reported. Field and laboratory data are presented for 714 groundwater and 577 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwater data indicate that uranium concentrations above the 85th percentile occur primarily in the Caddell, Wellborn, and Manning Formations of the Jackson Group; and the Yegua Formation of the Claiborne Group. Saline watermore » trends are also prominent in these formations. Stream sediment data indicate that uranium values above the 85th percentile correlate with high concentrations of cerium, niobium, thorium, titanium, yttrium, and zirconium. This elemental suite probably indicates that uranium is associated with resistate and/or heavy minerals.« less

Summary geochemical maps for samples of rock, stream sediment, and nonmagnetic heavy-mineral concentrate, Sweetwater Roadless Area, Mono County, California and Lyon and Douglas Counties, Nevada

USGS Publications Warehouse

Chaffee, Maurice A.

1986-01-01

Map A shows the locations of all sites where rock samples were collected for this report and the distributions of anomalous concentrations for 12 elements in the 127 rock samples collected. In a similar manner, map B shows the collection sites for 59 samples of minus-60-mesh stream sediment, and 59 samples of nonmagnetic heavy-mineral concentrate derived from stream sediment and also shows the distributions of anomalous concentrations for 13 elements in the stream-sediment samples and 17 elements in the concentrate samples. Map C shows outlines of those drainage basins containing samples of stream sediment and concentrate with anomalous element concentrations and also shows weighted values for each outlined basin based on the number of elements with anomalous concentrations in each stream-sediment and concentrate sample and on the degree to which these concentrations are anomalous in each sample.

Pesticide bioconcentration modelling for fruit trees.

PubMed

Paraíba, Lourival Costa

2007-01-01

The model presented allows simulating the pesticide concentration evolution in fruit trees and estimating the pesticide bioconcentration factor in fruits. Pesticides are non-ionic organic compounds that are degraded in soils cropped with woody species, fruit trees and other perennials. The model allows estimating the pesticide uptake by plants through the water transpiration stream and also the time in which maximum pesticide concentration occur in the fruits. The equation proposed presents the relationships between bioconcentration factor (BCF) and the following variables: plant water transpiration volume (Q), pesticide transpiration stream concentration factor (TSCF), pesticide stem-water partition coefficient (K(Wood,W)), stem dry biomass (M) and pesticide dissipation rate in the soil-plant system (k(EGS)). The modeling started and was developed from a previous model "Fruit Tree Model" (FTM), reported by Trapp and collaborators in 2003, to which was added the hypothesis that the pesticide degradation in the soil follows a first order kinetic equation. The FTM model for pesticides (FTM-p) was applied to a hypothetic mango plant cropping (Mangifera indica) treated with paclobutrazol (growth regulator) added to the soil. The model fitness was evaluated through the sensitivity analysis of the pesticide BCF values in fruits with respect to the model entry data variability.

Watershed Regressions for Pesticides (WARP) for Predicting Annual Maximum and Annual Maximum Moving-Average Concentrations of Atrazine in Streams

USGS Publications Warehouse

Stone, Wesley W.; Gilliom, Robert J.; Crawford, Charles G.

2008-01-01

Regression models were developed for predicting annual maximum and selected annual maximum moving-average concentrations of atrazine in streams using the Watershed Regressions for Pesticides (WARP) methodology developed by the National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey (USGS). The current effort builds on the original WARP models, which were based on the annual mean and selected percentiles of the annual frequency distribution of atrazine concentrations. Estimates of annual maximum and annual maximum moving-average concentrations for selected durations are needed to characterize the levels of atrazine and other pesticides for comparison to specific water-quality benchmarks for evaluation of potential concerns regarding human health or aquatic life. Separate regression models were derived for the annual maximum and annual maximum 21-day, 60-day, and 90-day moving-average concentrations. Development of the regression models used the same explanatory variables, transformations, model development data, model validation data, and regression methods as those used in the original development of WARP. The models accounted for 72 to 75 percent of the variability in the concentration statistics among the 112 sampling sites used for model development. Predicted concentration statistics from the four models were within a factor of 10 of the observed concentration statistics for most of the model development and validation sites. Overall, performance of the models for the development and validation sites supports the application of the WARP models for predicting annual maximum and selected annual maximum moving-average atrazine concentration in streams and provides a framework to interpret the predictions in terms of uncertainty. For streams with inadequate direct measurements of atrazine concentrations, the WARP model predictions for the annual maximum and the annual maximum moving-average atrazine concentrations can be used to characterize the probable levels of atrazine for comparison to specific water-quality benchmarks. Sites with a high probability of exceeding a benchmark for human health or aquatic life can be prioritized for monitoring.

Dual nitrate isotopes clarify the role of biological processing and hydrologic flow paths on nitrogen cycling in subtropical low-gradient watersheds

DOE PAGES

Griffiths, Natalie A.; Jackson, C. Rhett; McDonnell, Jeffrey J.; ...

2016-02-08

Nitrogen (N) is an important nutrient as it often limits productivity but in excess can impair water quality. Most studies on watershed N cycling have occurred in upland forested catchments where snowmelt dominates N export; fewer studies have focused on low-relief watersheds that lack snow. We examined watershed N cycling in three adjacent, low-relief watersheds in the Upper Coastal Plain of the southeastern United States to better understand the role of hydrological flow paths and biological transformations of N at the watershed scale. Groundwater was the dominant source of nitrified N to stream water in two of the three watersheds,more » while atmospheric deposition comprised 28% of stream water nitrate in one watershed. The greater atmospheric contribution may have been due to the larger stream channel area relative to total watershed area or the dominance of shallow subsurface flow paths contributing to stream flow in this watershed. There was a positive relationship between temperature and stream water ammonium concentrations and a negative relationship between temperature and stream water nitrate concentrations in each watershed suggesting that N cycling processes (i.e., nitrification and denitrification) varied seasonally. However, there were no clear patterns in the importance of denitrification in different water pools possibly because a variety of factors (i.e., assimilatory uptake, dissimilatory uptake, and mixing) affected nitrate concentrations. In conclusion, together, these results highlight the hydrological and biological controls on N cycling in low-gradient watersheds and variability in N delivery flow paths among adjacent watersheds with similar physical characteristics.« less

Chemical characteristics and temporal trends in eight streams of the Catskill Mountains, New York

USGS Publications Warehouse

Murdoch, Peter S.; Stoddard, J.L.

1993-01-01

Discharge to concentration relationships for eight streams studied by the U.S. Geological Survey (USGS) as part of the U.S. Environmental Protection Agency's (U.S. EPA) Long-Term Monitoring Project (1983-89) indicate acidification of some streams by H2SO4 and HNO3 in atmospheric deposition and by organic acids in soils. Concentrations of major ions in precipitation were similar to those reported at other sites in the northeastern United States. Average concentrations of SO42- and NO3- were similar among streams, but base cation concentrations differed widely, and these differences paralleled the differences in acid neutralizing capacity (ANC). Baseflow ANC is not a reliable predictor of stream acidity at high flow; some streams with high baseflow ANC (> 150 ??eq L-1) declined to near zero ANC at high flow, and one stream with low baseflow ANC (< 50 ??eq L-1) did not approach zero ANC as flow increased. Episodic decreases in ANC and pH during peak flows were associated with increased concentrations of NO3- and dissolved organic carbon (DOC). Aluminum concentrations exceeding 300 ??g L-1 were observed during peak flows in headwater streams of the Neversink River and Rondout Creek. Seasonal Kendall Tau tests for temporal trends indicate that SO42- concentrations in streamwater generally decreased and NO3- concentrations increased during the period 1983-1989. Combined acid anion concentrations (SO42- + NO3-) were generally unchanged throughout the period of record, indicating both that the status of these streams with respect to acidic deposition is unchanged, and that NO3- is gradually replacing SO42- as the dominant acid anion in the Catskill streams.Discharge to concentration relationships for eight streams studied by the US Geological Survey (USGS) as part of the Environmental Protection Agency's (US EPA) Long-term monitoring project (19831-89) indicate acidification of some streams by H2SO4 and HNO3 in atmospheric deposition and by organic acids in soils. Concentrations of major ions in precipitations were similar to those reported at other sites in the northeastern United States. Average concentrations of SO42- and No3- were similar among streams, but base cation concentrations differed widely, and these differences parallelel the differences in acid neutralizing capacity (ANC).

Mercury in Fish, Bed Sediment, and Water from Streams Across the United States, 1998-2005

USGS Publications Warehouse

Scudder, Barbara C.; Chasar, Lia C.; Wentz, Dennis A.; Bauch, Nancy J.; Brigham, Mark E.; Moran, Patrick W.; Krabbenhoft, David P.

2009-01-01

Mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury (MeHg) bioaccumulation. Sampled settings include stream basins that were agricultural, urbanized, undeveloped (forested, grassland, shrubland, and wetland land cover), and mined (for gold and Hg). Each site was sampled one time during seasonal low flow. Predator fish were targeted for collection, and composited samples of fish (primarily skin-off fillets) were analyzed for total Hg (THg), as most of the Hg found in fish tissue (95-99 percent) is MeHg. Samples of bed sediment and stream water were analyzed for THg, MeHg, and characteristics thought to affect Hg methylation, such as loss-on-ignition (LOI, a measure of organic matter content) and acid-volatile sulfide in bed sediment, and pH, dissolved organic carbon (DOC), and dissolved sulfate in water. Fish-Hg concentrations at 27 percent of sampled sites exceeded the U.S. Environmental Protection Agency human-health criterion of 0.3 micrograms per gram wet weight. Exceedances were geographically widespread, although the study design targeted specific sites and fish species and sizes, so results do not represent a true nationwide percentage of exceedances. The highest THg concentrations in fish were from blackwater coastal-plain streams draining forests or wetlands in the eastern and southeastern United States, as well as from streams draining gold- or Hg-mined basins in the western United States (1.80 and 1.95 micrograms THg per gram wet weight, respectively). For unmined basins, length-normalized Hg concentrations in largemouth bass were significantly higher in fish from predominantly undeveloped or mixed-land-use basins compared to urban basins. Hg concentrations in largemouth bass from unmined basins were correlated positively with basin percentages of evergreen forest and also woody wetland, especially with increasing proximity of these two land-cover types to the sampling site; this underscores the greater likelihood for Hg bioaccumulation to occur in these types of settings. Increasing concentrations of MeHg in unfiltered stream water, and of bed-sediment MeHg normalized by LOI, and decreasing pH and dissolved sulfate were also important in explaining increasing Hg concentrations in largemouth bass. MeHg concentrations in bed sediment correlated positively with THg, LOI, and acid-volatile sulfide. Concentrations of MeHg in water correlated positively with DOC, ultraviolet absorbance, and THg in water, the percentage of MeHg in bed sediment, and the percentage of wetland in the basin.

Factors influencing detection of eDNA from a stream-dwelling amphibian

USGS Publications Warehouse

Pilliod, David S.; Goldberg, Caren S.; Arkle, Robert S.; Waits, Lisette P.

2013-01-01

Environmental DNA (eDNA) methods for detecting and estimating abundance of aquatic species are emerging rapidly, but little is known about how processes such as secretion rate, environmental degradation, and time since colonization or extirpation from a given site affect eDNA measurements. Using stream-dwelling salamanders and quantitative PCR (qPCR) analysis, we conducted three experiments to assess eDNA: (i) production rate; (ii) persistence time under different temperature and light conditions; and (iii) detectability and concentration through time following experimental introduction and removal of salamanders into previously unoccupied streams. We found that 44–50 g individuals held in aquaria produced 77 ng eDNA/h for 2 h, after which production either slowed considerably or began to equilibrate with degradation. eDNA in both full-sun and shaded treatments degraded exponentially to 2) and when samples were collected within 5 m of the animals. Concentrations of eDNA detected were very low and increased steadily from 6–24 h after introduction, reaching 0.0022 ng/L. Within 1 h of removing salamanders from the stream, eDNA was no longer detectable. These results suggest that eDNA detectability and concentration depend on production rates of individuals, environmental conditions, density of animals, and their residence time.

Solute and sediment export from Amazon forest and soybean headwater streams.

PubMed

Riskin, Shelby H; Neill, Christopher; Jankowski, KathiJo; Krusche, Alex V; McHorney, Richard; Elsenbeer, Helmut; Macedo, Marcia N; Nunes, Darlisson; Porder, Stephen

2017-01-01

Intensive cropland agriculture commonly increases streamwater solute concentrations and export from small watersheds. In recent decades, the lowland tropics have become the world's largest and most important region of cropland expansion. Although the effects of intensive cropland agriculture on streamwater chemistry and watershed export have been widely studied in temperate regions, their effects in tropical regions are poorly understood. We sampled seven headwater streams draining watersheds in forest (n = 3) or soybeans (n = 4) to examine the effects of soybean cropping on stream solute concentrations and watershed export in a region of rapid soybean expansion in the Brazilian state of Mato Grosso. We measured stream flows and concentrations of NO 3 - , PO 4 3- , SO 4 2- , Cl - , NH 4 + , Ca 2+ , Mg 2+ , Na + , K + , Al 3+ , Fe 3+ , and dissolved organic carbon (DOC) biweekly to monthly to determine solute export. We also measured stormflows and stormflow solute concentrations in a subset of watersheds (two forest, two soybean) during two/three storms, and solutes and δ 18 O in groundwater, rainwater, and throughfall to characterize watershed flowpaths. Concentrations of all solutes except K + varied seasonally in streamwater, but only Fe 3+ concentrations differed between land uses. The highest streamwater and rainwater solute concentrations occurred during the peak season of wildfires in Mato Grosso, suggesting that regional changes in atmospheric composition and deposition influence seasonal stream solute concentrations. Despite no concentration differences between forest and soybean land uses, annual export of NH 4 + , PO 4 3- , Ca 2+ , Fe 3+ , Na + , SO 4 2- , DOC, and TSS were significantly higher from soybean than forest watersheds (5.6-fold mean increase). This increase largely reflected a 4.3-fold increase in water export from soybean watersheds. Despite this increase, total solute export per unit watershed area (i.e., yield) remained low for all watersheds (<1 kg NO 3 - N·ha -1 ·yr -1 , <2.1 kg NH 4 + -N·ha -1 ·yr -1 , <0.2 kg PO 4 3- -P·ha -1 ·yr -1 , <1.5 kg Ca 2+ ·ha -1 ·yr -1 ). Responses of both streamflows and solute concentrations to crop agriculture appear to be controlled by high soil hydraulic conductivity, groundwater-dominated hydrologic flowpaths on deep soils, and the absence of nitrogen fertilization. To date, these factors have buffered streams from the large increases in solute concentrations that often accompany intensive croplands in other locations. © 2016 by the Ecological Society of America.

Water chemistry in 179 randomly selected Swedish headwater streams related to forest production, clear-felling and climate.

PubMed

Löfgren, Stefan; Fröberg, Mats; Yu, Jun; Nisell, Jakob; Ranneby, Bo

2014-12-01

From a policy perspective, it is important to understand forestry effects on surface waters from a landscape perspective. The EU Water Framework Directive demands remedial actions if not achieving good ecological status. In Sweden, 44 % of the surface water bodies have moderate ecological status or worse. Many of these drain catchments with a mosaic of managed forests. It is important for the forestry sector and water authorities to be able to identify where, in the forested landscape, special precautions are necessary. The aim of this study was to quantify the relations between forestry parameters and headwater stream concentrations of nutrients, organic matter and acid-base chemistry. The results are put into the context of regional climate, sulphur and nitrogen deposition, as well as marine influences. Water chemistry was measured in 179 randomly selected headwater streams from two regions in southwest and central Sweden, corresponding to 10 % of the Swedish land area. Forest status was determined from satellite images and Swedish National Forest Inventory data using the probabilistic classifier method, which was used to model stream water chemistry with Bayesian model averaging. The results indicate that concentrations of e.g. nitrogen, phosphorus and organic matter are related to factors associated with forest production but that it is not forestry per se that causes the excess losses. Instead, factors simultaneously affecting forest production and stream water chemistry, such as climate, extensive soil pools and nitrogen deposition, are the most likely candidates The relationships with clear-felled and wetland areas are likely to be direct effects.

Quantifying the impact of septic tank systems on eutrophication risk in rural headwaters.

PubMed

Withers, P J A; Jarvie, H P; Stoate, C

2011-04-01

Septic tank systems (STS) are a potential source of nutrient emissions to surface waters but few data exist in the UK to quantify their significance for eutrophication. We monitored the impact of STS on nutrient concentrations in a stream network around a typical English village over a 1-year period. Septic tank effluent discharging via a pipe directly into one stream was highly concentrated in soluble N (8-63mgL(-1)) and P (<1-14mgL(-1)) and other nutrients (Na, K, Cl, B and Mn) typical of detergent and household inputs. Ammonium-N (NH(4)N) and soluble reactive P (SRP) fractions were dominant (70-85% of total) and average concentrations of nitrite-N (NO(2)N) were above levels considered harmful to fish (0.1mgL(-1)). Lower nutrient concentrations were recorded at a ditch and a stream site, but range and average values downstream of rural habitation were still 4 to 10-fold greater than those in upstream sections. At the ditch site, where flow volumes were low, annual flow-weighted concentrations of NH(4)N and SRP increased from 0.04 and 0.07mgL(-1), respectively upstream to 0.55 and 0.21mgL(-1) downstream. At the stream site, flow volumes were twice as large and flow-weighted concentrations increased much less; from 0.04 to 0.21mgL(-1) for NH(4)N and from 0.06 to 0.08mgL(-1) for SRP. At all sites, largest nutrient concentrations were recorded under low flow and stream discharge was the most important factor determining the eutrophication impact of septic tank systems. The very high concentrations, intercorrelation and dilution patterns of SRP, NH(4)-N and the effluent markers Na and B suggested that soakaways in the heavy clay catchment soils were not retaining and treating the septic tank effluents efficiently, with profound implications for stream biodiversity. Water companies, water regulators and rural communities therefore need to be made more aware of the potential impacts of STS on water quality so that their management can be optimised to reduce the risk of potential eutrophication and toxicity to aquatic ecosystems during summer low flow periods. Copyright © 2011 Elsevier Ltd. All rights reserved.

Estimating the gas and dye quantities for modified tracer technique measurements of stream reaeration coefficients

USGS Publications Warehouse

Rathbun, R.E.

1979-01-01

Measuring the reaeration coefficient of a stream with a modified tracer technique has been accomplished by injecting either ethylene or ethylene and propane together and a rhodamine-WT dye solution into the stream. The movement of the tracers through the stream reach after injection is described by a one-dimensional diffusion equation. The peak concentrations of the tracers at the downstream end of the reach depend on the concentrations of the tracers in the stream at the injection site, the longitudinal dispersion coefficient, the mean water velocity, the length of the reach, and the duration of the injection period. The downstream gas concentrations also depend on the gas desorption coefficients of the reach. The concentrations of the tracer gases in the stream at the injection site depend on the flow rates of the gases through the injection diffusers, the efficiency of the gas absorption process, and the stream discharge. The concentration of dye in the stream at the injection site depends on the flow rate of the dye solution, the concentration of the dye solution, and the stream discharge. Equations for estimating the gas flow rates, the quantities of the gases, the dye concentration, and the quantity of dye together with procedures for determining the variables in these equations are presented. (Woodard-USGS)

Patch occupancy of stream fauna across a land cover gradient in the southern Appalachians, USA

USGS Publications Warehouse

Frisch, John R.; Peterson, James T.; Cecala, Kristen K.; Maerz, John C.; Jackson, C. Rhett; Gragson, Ted L.; Pringle, Catherine M.

2016-01-01

We modeled patch occupancy to examine factors that best predicted the prevalence of four functionally important focal stream consumers (Tallaperla spp., Cambarus spp.,Pleurocera proxima, and Cottus bairdi) among 37 reaches within the Little Tennessee River basin of the southern Appalachian Mountains, USA. We compared 34 models of patch occupancy to examine the association of catchment and reach scale factors that varied as a result of converting forest to agricultural or urban land use. Occupancy of our taxa was linked to parameters reflecting both catchment and reach extent characteristics. At the catchment level, forest cover or its conversion to agriculture was a major determinant of occupancy for all four taxa. Patch occupancies of Tallaperla, Cambarus, and C. bairdi were positively, and Pleurocera negatively, correlated with forest cover. Secondarily at the reach level, local availability of large woody debris was important forCambarus, availability of large cobble substrate was important for C. bairdi, and stream calcium concentration was important for P. proxima. Our results show the abundance of stream organisms was determined by the taxon-dependent interplay between catchment- and reach-level factors.

Sediment oxygen demand in eastern Kansas streams, 2014 and 2015

USGS Publications Warehouse

Foster, Guy M.; King, Lindsey R.; Graham, Jennifer L.

2016-08-29

Dissolved oxygen concentrations in streams are affected by physical, chemical, and biological factors in the water column and streambed, and are an important factor for the survival of aquatic organisms. Sediment oxygen demand (SOD) rates in Kansas streams are not well understood. During 2014 and 2015, the U.S. Geological Survey, in cooperation with the Kansas Department of Health and Environment, measured SOD at eight stream sites in eastern Kansas to quantify SOD rates and variability with respect to season, land use, and bottom-sediment characteristics. Sediment oxygen demand rates (SODT) ranged from 0.01 to 3.15 grams per square meter per day at the ambient temperature of the measurements. The summer mean SOD rate was 3.0-times larger than the late fall mean rate, likely because of increased biological activity at warm water temperatures. Given the substantial amount of variability in SOD rates possible within sites, heterogeneity of substrate type is an important consideration when designing SOD studies and interpreting the results. Sediment oxygen demand in eastern Kansas streams was correlated with land use and streambed-sediment characteristics, though the strength of relations varied seasonally. The small number of study sites precluded a more detailed analysis. The effect of basin land use and streambed sediment characteristics on SOD is currently (2016) not well understood, and there may be many contributing factors including basin influences on water quality that affect biogeochemical cycles and the biological communities supported by the stream.

DWPF RECYCLE EVAPORATOR FLOWSHEET EVALUATION (U)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, M

2005-04-30

The Defense Waste Processing Facility (DWPF) converts the high level waste slurries stored at the Savannah River Site into borosilicate glass for long-term storage. The vitrification process results in the generation of approximately five gallons of dilute recycle streams for each gallon of waste slurry vitrified. This dilute recycle stream is currently transferred to the H-area Tank Farm and amounts to approximately 1,400,000 gallons of effluent per year. Process changes to incorporate salt waste could increase the amount of effluent to approximately 2,900,000 gallons per year. The recycle consists of two major streams and four smaller streams. The first majormore » recycle stream is condensate from the Chemical Process Cell (CPC), and is collected in the Slurry Mix Evaporator Condensate Tank (SMECT). The second major recycle stream is the melter offgas which is collected in the Off Gas Condensate Tank (OGCT). The four smaller streams are the sample flushes, sump flushes, decon solution, and High Efficiency Mist Eliminator (HEME) dissolution solution. These streams are collected in the Decontamination Waste Treatment Tank (DWTT) or the Recycle Collection Tank (RCT). All recycle streams are currently combined in the RCT and treated with sodium nitrite and sodium hydroxide prior to transfer to the tank farm. Tank Farm space limitations and previous outages in the 2H Evaporator system due to deposition of sodium alumino-silicates have led to evaluation of alternative methods of dealing with the DWPF recycle. One option identified for processing the recycle was a dedicated evaporator to concentrate the recycle stream to allow the solids to be recycled to the DWPF Sludge Receipt and Adjustment Tank (SRAT) and the condensate from this evaporation process to be sent and treated in the Effluent Treatment Plant (ETP). In order to meet process objectives, the recycle stream must be concentrated to 1/30th of the feed volume during the evaporation process. The concentrated stream must be pumpable to the DWPF SRAT vessel and should not precipitate solids to avoid fouling the evaporator vessel and heat transfer coils. The evaporation process must not generate excessive foam and must have a high Decontamination Factor (DF) for many species in the evaporator feed to allow the condensate to be transferred to the ETP. An initial scoping study was completed in 2001 to evaluate the feasibility of the evaporator which concluded that the concentration objectives could be met. This initial study was based on initial estimates of recycle concentration and was based solely on OLI modeling of the evaporation process. The Savannah River National Laboratory (SRNL) has completed additional studies using simulated recycle streams and OLI{reg_sign} simulations. Based on this work, the proposed flowsheet for the recycle evaporator was evaluated for feasibility, evaporator design considerations, and impact on the DWPF process. This work was in accordance with guidance from DWPF-E and was performed in accordance with the Technical Task and Quality Assurance Plan.« less

Effect of land use and hydrological processes on Escherichia coli concentrations in streams of tropical, humid headwater catchments.

PubMed

Rochelle-Newall, Emma J; Ribolzi, Olivier; Viguier, Marion; Thammahacksa, Chanthamousone; Silvera, Norbert; Latsachack, Keooudone; Dinh, Rinh Pham; Naporn, Piyapong; Sy, Hai Tran; Soulileuth, Bounsamay; Hmaimum, Nikom; Sisouvanh, Pem; Robain, Henri; Janeau, Jean-Louis; Valentin, Christian; Boithias, Laurie; Pierret, Alain

2016-09-08

Lack of access to clean water and adequate sanitation continues to be a major brake on development. Here we present the results of a 12-month investigation into the dynamics of Escherichia coli, a commonly used indicator of faecal contamination in water supplies, in three small, rural catchments in Laos, Thailand and Vietnam. We show that land use and hydrology are major controlling factors of E. coli concentrations in streamwater and that the relative importance of these two factors varies between the dry and wet seasons. In all three catchments, the highest concentrations were observed during the wet season when storm events and overland flow were highest. However, smaller peaks of E. coli concentration were also observed during the dry season. These latter correspond to periods of intense farming activities and small, episodic rain events. Furthermore, vegetation type, through land use and soil surface crusting, combined with mammalian presence play an important role in determining E. coli loads in the streams. Finally, sampling during stormflow revealed the importance of having appropriate sampling protocols if information on maximum contamination levels is required as grab sampling at a fixed time step may miss important peaks in E. coli numbers.

Effect of land use and hydrological processes on Escherichia coli concentrations in streams of tropical, humid headwater catchments

NASA Astrophysics Data System (ADS)

Rochelle-Newall, Emma J.; Ribolzi, Olivier; Viguier, Marion; Thammahacksa, Chanthamousone; Silvera, Norbert; Latsachack, Keooudone; Dinh, Rinh Pham; Naporn, Piyapong; Sy, Hai Tran; Soulileuth, Bounsamay; Hmaimum, Nikom; Sisouvanh, Pem; Robain, Henri; Janeau, Jean-Louis; Valentin, Christian; Boithias, Laurie; Pierret, Alain

2016-09-01

Lack of access to clean water and adequate sanitation continues to be a major brake on development. Here we present the results of a 12-month investigation into the dynamics of Escherichia coli, a commonly used indicator of faecal contamination in water supplies, in three small, rural catchments in Laos, Thailand and Vietnam. We show that land use and hydrology are major controlling factors of E. coli concentrations in streamwater and that the relative importance of these two factors varies between the dry and wet seasons. In all three catchments, the highest concentrations were observed during the wet season when storm events and overland flow were highest. However, smaller peaks of E. coli concentration were also observed during the dry season. These latter correspond to periods of intense farming activities and small, episodic rain events. Furthermore, vegetation type, through land use and soil surface crusting, combined with mammalian presence play an important role in determining E. coli loads in the streams. Finally, sampling during stormflow revealed the importance of having appropriate sampling protocols if information on maximum contamination levels is required as grab sampling at a fixed time step may miss important peaks in E. coli numbers.

The influence of stormwater management practices on denitrification rates of receiving streams in an urban watershed

NASA Astrophysics Data System (ADS)

Cronenberger, M. S.; McMillan, S. K.

2011-12-01

Increasing urbanization and the subsequent disruption of floodplains has led to the need for implementing stormwater management strategies to mitigate the effects of urbanization, including soil and streambank erosion, increased export of nutrients and contaminants and decreased biotic richness. Excessive stormwater runoff due to the abundance of impervious surfaces associated with an urban landscape has led to the ubiquitous use of best management practices (BMPs) to attenuate runoff events and prevent the destructive delivery of large volumes of water to stream channels. As a result, effluent from BMPs (i.e. wetlands and wet ponds) has the potential to alter the character of the receiving stream channel and thus, key ecosystem processes such as denitrification. The purpose of this study was to determine the extent to which BMPs, in the form of constructed wetlands and wet ponds, influence in-stream denitrification rates in the urban landscape of Charlotte, NC. Four sites, two of each BMP type, were evaluated. Sediment samples were collected upstream and downstream of the BMP outflow from May-July 2011 to determine the effect of wetland discharge on in-stream nitrogen removal via denitrification. Denitrification rates were determined using the acetylene block method; water column nutrient and carbon concentrations and sediment organic matter content were also measured. Generally, wetland sites exhibited higher denitrification rates, nitrate concentrations and sediment organic matter content. Our work and others has demonstrated a significant positive correlation between nitrate concentration and denitrification rates, which is the likely driver of the higher observed rates at the wetland sites. Geomorphology was also found to be a key factor in elevated denitrification rates at sites with riffles and boulder jams. Sediment organic matter was found to be higher downstream of BMP outflows at all four sites, but demonstrated no significant relationship with denitrification rates. We are continuing to investigate these spatial (e.g. BMPs, streams) and temporal (e.g. storm pulse, delayed wetland release) patterns, particularly in the context of factors that influence the specific drivers of denitrification. Understanding these patterns is critical to managing stormwater in urban landscapes as we aim to improve water quality while enhancing ecosystem functions.

Effect of whole catchment liming on the episodic acidification of two adirondack streams

USGS Publications Warehouse

Newton, R.M.; Burns, Douglas A.; Blette, V.L.; Driscoll, C.T.

1996-01-01

During the fall of 1989 7.7Mg/ha of calcium carbonate was applied on two tributary catchments (40 ha and 60 ha) to Woods Lake, a small (25 ha) acidic headwater lake in the western Adirondack region of New York. Stream-water chemistry in both catchment tributaries responded immediately. Acid-neutralizing capacity (ANC) increased by more than 200 ??eq/L in one of the streams and more than 1000 ??eq/L in the other, from pre-liming values which ranged from -25 to +40 ??eq/L. The increase in ANC was primarily due to increases in dissolved Ca2+ concentrations. Most of the initial response of the streams was due to the dissolution of calcite that fell directly into the stream channels and adjacent wetlands. A small beaver impoundment and associated wetlands were probably responsible for the greater response observed in one of the streams. After the liming of subcatchmentIV (60 ha), Ca2+ concentrations increased with increasing stream discharge in the stream during fall rain events, suggesting a contribution from calcite dissolved within the soil and transported to the stream by surface runoff or shallow interflow. Concentrations of other ions not associated with the calcite (e.g. Na+) decreased during fall rain events, presumably due to mixing of solute-rich base flow with more dilute shallow interflow. The strong relation between changes in Ca2+ and changes in NO3- concentrations during spring snowmelt, (r2 = 0.93, slope = 0.96, on an equivalent basis) suggests that both solutes had a common source in the organic horizon of the soil. Increases in NO3- concentrations during snowmelt were balanced by increases in Ca2+ that was released either directly from the calcite or from exchange sites, mitigating episodic acidification of the stream. However, high ambient NO3- concentrations and relatively low ambient Ca2+ concentrations in the stream during the spring caused the stream to become acidic despite the CaCO3 treatment. In stream WO2 (40ha), Ca2+ concentrations were much higher than in stream WO4 because of the dissolution of calcite which fell directly into the upstream beaver pond and its associated wetlands. Calcium concentrations decreased as both NO3- concentrations and stream discharge increased, due to the dilution of Ca-enriched beaver pond water by shallow interflow. Despite this dilution, Ca2+ concentrations were high enough to more than balance strong acid anion (SO42-, NO3-, Cl-) concentrations, resulting in a positive ANC in this stream throughout the year. These data indicate that liming of wetlands and beaver ponds is more effective than whole catchment liming in neutralizing acidic surface waters. ?? 1996 Kluwer Academic Publishers.

Enrichment and geo-accumulation of heavy metals and risk assessment of sediments of the Kurang Nallah--feeding tributary of the Rawal Lake Reservoir, Pakistan.

PubMed

Zahra, Azmat; Hashmi, Muhammad Zaffar; Malik, Riffat Naseem; Ahmed, Zulkifl

2014-02-01

Heavy metal concentrations in sediments of the Kurang stream: a principal feeding tributary of the Rawal Lake Reservoir were investigated using enrichment factor (EF), geoaccumulation index (Igeo) and metal pollution index (MPI) to determine metal accumulation, distribution and its pollution status. Sediment samples were collected from twenty one sites during two year monitoring in pre- and post-monsoon seasons (2007-2008). Heavy metal toxicity risk was assessed using Sediment Quality Guidelines (SQGs), effect range low/effect range median values (ERL/ERM), and threshold effect level/probable effect level (TEL/PEL). Greater mean concentrations of Ni, Mn and Pb were recorded in post-monsoon season whereas metal accumulation pattern in pre-monsoon season followed the order: Zn>Mn>Ni>Cr>Co>Cd>Pb>Cu>Li. Enrichment factor (EF) and geoaccumulation (Igeo) values showed that sediments were loaded with Cd, Zn, Ni and Mn. Comparison with uncontaminated background values showed higher concentrations of Cd, Zn and Ni than respective average shale values. Concentrations of Ni and Zn were above ERL values; however, Ni concentration exceeded the ERM values. Sediment contamination was attributed to anthropogenic and natural processes. The results can be used for effective management of fresh water hilly streams of Pakistan. © 2013.

Influence of environmental factors on biotic responses to nutrient enrichment in agricultural streams

USGS Publications Warehouse

Maret, Terry R.; Konrad, Christopher P.; Tranmer, Andrew W.

2010-01-01

The influence of environmental factors on biotic responses to nutrients was examined in three diverse agricultural regions of the United States. Seventy wadeable sites were selected along an agricultural land use gradient while minimizing natural variation within each region. Nutrients, habitat, algae, macroinvertebrates, and macrophyte cover were sampled during a single summer low-flow period in 2006 or 2007. Continuous stream stage and water temperature were collected at each site for 30 days prior to sampling. Wide ranges of concentrations were found for total nitrogen (TN) (0.07-9.61 mg/l) and total phosphorus (TP) (R2) for nutrients and biotic measures across all sites ranged from 0.08 to 0.32 and generally were not higher within each region. The biotic measures (RCHL, SCHL, and AQM) were combined in an index to evaluate eutrophic status across sites that could have different biotic responses to nutrient enrichment. Stepwise multiple regression identified TN, percent canopy, median riffle depth, and daily percent change in stage as significant factors for the eutrophic index (R2 = 0.50, p < 0.001). A TN threshold of 0.48 mg/l was identified where eutrophic index scores became less responsive to increasing TN concentrations, for all sites. Multiple plant growth indicators should be used when evaluating eutrophication, especially when streams contain an abundance of macrophytes.

Impacts by point and diffuse micropollutant sources on the stream water quality at catchment scale

NASA Astrophysics Data System (ADS)

Petersen, M. F.; Eriksson, E.; Binning, P. J.; Bjerg, P. L.

2012-04-01

The water quality of surface waters is threatened by multiple anthropogenic pollutants and the large variety of pollutants challenges the monitoring and assessment of the water quality. The aim of this study was to characterize and quantify both point and diffuse sources of micropollutants impacting the water quality of a stream at catchment scale. Grindsted stream in western Jutland, Denmark was used as a study site. The stream passes both urban and agricultural areas and is impacted by severe groundwater contamination in Grindsted city. Along a 12 km reach of Grindsted stream, the potential pollution sources were identified including a pharmaceutical factory site with a contaminated old drainage ditch, two waste deposits, a wastewater treatment plant, overflow structures, fish farms, industrial discharges and diffuse agricultural and urban sources. Six water samples were collected along the stream and analyzed for general water quality parameters, inorganic constituents, pesticides, sulfonamides, chlorinated solvents, BTEXs, and paracetamol and ibuprofen. The latter two groups were not detected. The general water quality showed typical conditions for a stream in western Jutland. Minor impacts by releases of organic matter and nutrients were found after the fish farms and the waste water treatment plant. Nickel was found at concentrations 5.8 - 8.8 μg/l. Nine pesticides and metabolites of both agricultural and urban use were detected along the stream; among these were the two most frequently detected and some rarely detected pesticides in Danish water courses. The concentrations were generally consistent with other findings in Danish streams and in the range 0.01 - 0.09 μg/l; except for metribuzin-diketo that showed high concentrations up to 0.74 μg/l. The groundwater contamination at the pharmaceutical factory site, the drainage ditch and the waste deposits is similar in composition containing among others sulfonamides and chlorinated solvents (including vinyl chloride). Vinyl chloride concentrations surpassed Danish stream water quality criteria with a factor 10. The largest chemical impact occurs at the reach downstream Grindsted city revealing that the main contaminant groundwater discharge zones are found here. The contaminant plume from the factory site north of the stream is known to impact the stream whereas the impact by the old landfill south of the stream remains to be assessed. A conceptual model of the chemical impacts by the identified sources was made, and high impact was assigned to the contaminant plume from the factory site and to the diffuse sources of urban-use and agricultural pesticides. The next step will be a quantification of the sources, which will be presented at the conference.

Temporal changes in nitrogen and phosphorus concentrations with comparisons to conservation practices and agricultural activities in the Lower Grand River, Missouri and Iowa, and selected watersheds, 1969–2015

USGS Publications Warehouse

Krempa, Heather M.; Flickinger, Allison K.

2017-08-01

This report presents the results of a cooperative study by the U.S. Geological Survey and Missouri Department of Natural Resources to estimate total nitrogen (TN) and total phosphorus (TP) concentrations at monitoring sites within and near the Lower Grand River hydrological unit. The primary objectives of the study were to quantify temporal changes in TN and TP concentrations and compare those concentrations to conservation practices and agricultural activities. Despite increases in funding during 2011–15 for conservation practices in the Lower Grand River from the Mississippi River Basin Healthy Watersheds Initiative, decreases in flow-normalized TN and TP concentrations during this time at the long-term Grand River site were less than at other long-term sites, which did not receive funding from the Mississippi River Basin Healthy Watersheds Initiative. The relative differences in the magnitude of flow-normalized TN and TP concentrations among long-term sites are directly related to the amount of agricultural land use within the watershed. Significant relations were determined between nitrogen from cattle manure and flow-normalized TN concentrations at selected long-term sites, indicating livestock manure may be a substantial source of nitrogen within the selected long-term site watersheds. Relations between flow-normalized TN and TP concentrations with Conservation Reserve Program acres and with nitrogen and phosphorus from commercial fertilizer indicate that changes in these factors alone did not have a substantial effect on stream TN and TP concentrations; other landscape activities, runoff, within-bank nutrients that are suspended during higher streamflows, or a combination of these have had a greater effect on stream TN and TP concentrations; or there is a lag time that is obscuring relations. Temporal changes in flow-adjusted TN and TP concentrations were not substantial at Lower Grand River Mississippi River Basin Healthy Watersheds Initiative sites, indicating factors besides stream variability did not have substantial effects on TN and TP concentrations. Flow-weighted TN and TP concentrations at Lower Grand River Mississippi River Basin Healthy Watershed Initiative sites increase with increasing streamflow, which indicates runoff, within-bank nutrients that are suspended during higher streamflows, or both, have more effect on stream TN and TP concentrations than consistent point sources or groundwater sources. Timing of TN and TP concentration increases compared to streamflow increases indicate that nitrogen and phosphorus loads are more strongly related to streamflow than to a particular period of the year, indicating that runoff, within-bank nutrients that are suspended during higher streamflows, or both are a substantial source of nutrients regardless of timing.

Comparison of Hydrologic and Water-Quality Characteristics of Two Native Tallgrass Prairie Streams with Agricultural Streams in Missouri and Kansas

USGS Publications Warehouse

Heimann, David C.

2009-01-01

This report presents the results of a study by the U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, to analyze and compare hydrologic and water-quality characteristics of tallgrass prairie and agricultural basins located within the historical distribution of tallgrass prairie in Missouri and Kansas. Streamflow and water-quality data from two remnant, tallgrass prairie basins (East Drywood Creek at Prairie State Park, Missouri, and Kings Creek near Manhattan, Kansas) were compared to similar data from agricultural basins in Missouri and Kansas. Prairie streams, especially Kings Creek in eastern Kansas, received a higher percentage of base flow and a lower percentage of direct runoff than similar-sized agricultural streams in the region. A larger contribution of direct runoff from the agricultural streams made them much flashier than prairie streams. During 22 years of record, the Kings Creek base-flow component averaged 66 percent of total flow, but base flow was only 16 to 26 percent of flows at agricultural sites of various record periods. The large base-flow component likely is the result of greater infiltration of precipitation in prairie soils and the resulting greater contribution of groundwater to streamflow. The 1- and 3-day annual maximum flows were significantly greater at three agricultural sites than at Kings Creek. The effects of flashier agricultural streams on native aquatic biota are unknown, but may be an important factor in the sustainability of some native aquatic species. There were no significant differences in the distribution of dissolved-oxygen concentrations at prairie and agricultural sites, and some samples from most sites fell below the 5 milligrams per liter Missouri and Kansas standard for the protection of aquatic life. More than 10 percent of samples from the East Drywood Creek prairie stream were less than this standard. These data indicate low dissolved-oxygen concentrations during summer low-flow periods may be a natural phenomenon for small prairie streams in the Osage Plains. Nutrient concentrations including total nitrogen, ammonia, nitrate, and total phosphorus were significantly less in base-flow and runoff samples from prairie streams than from agricultural streams. The total nitrogen concentration at all sites other than one of two prairie sampling sites were, on occasion, above the U.S. Environmental Protection Agency recommended criterion for total nitrogen for the prevention of nutrient enrichment, and typically were above this recommended criterion in runoff samples at all sites. Nitrate and total phosphorus concentrations in samples from the prairie streams generally were below the U.S. Environmental Protection Agency recommended nutrient criteria in base-flow and runoff samples, whereas samples from agricultural sites generally were below the criteria in base-flow samples and generally above in runoff samples. The lower concentrations of nutrient species in prairie streams is likely because prairies are not fertilized like agricultural basins and prairie basins are able to retain nutrients better than agricultural basins. This retention is enhanced by increased infiltration of precipitation into the prairie soils, decreased surface runoff, and likely less erosion than in agricultural basins. Streamflow in the small native prairie streams had more days of zero flow and lower streamflow yields than similar-sized agricultural streams. The prairie streams were at zero flow about 50 percent of the time, and the agricultural streams were at zero flow 25 to 35 percent of the time. Characteristics of the prairie basins that could account for the greater periods of zero flow and lower yields when compared to agricultural streams include greater infiltration, greater interception and evapotranspiration, shallower soils, and possible greater seepage losses in the prairie basins. Another difference between the prairie and agricultural strea

Nutrient concentrations and their relations to the biotic integrity of wadeable streams in Wisconsin

USGS Publications Warehouse

Robertson, Dale M.; Graczyk, David J.; Garrison, Paul J.; Wang, Lizhu; LaLiberte, Gina; Bannerman, Roger

2006-01-01

Excessive nutrient (phosphorus and nitrogen) loss from watersheds is frequently associated with degraded water quality in streams. To reduce this loss, agricultural performance standards and regulations for croplands and livestock operations are being proposed by various States. In addition, the U.S. Environmental Protection Agency is establishing regionally based nutrient criteria that can be refined by each State to determine whether actions are needed to improve a stream's water quality. More confidence in the environmental benefits of the proposed performance standards and nutrient criteria will be possible with a better understanding of the biotic responses to a range of nutrient concentrations in different environmental settings. The U.S. Geological Survey and the Wisconsin Department of Natural Resources collected data from 240 wadeable streams throughout Wisconsin to: 1) describe how nutrient concentrations and biotic-community structure vary throughout the State; 2) determine which environmental characteristics are most strongly related to the distribution of nutrient concentrations; 3) determine reference water-quality and biotic conditions for different areas of the State; 4) determine how the biotic community of streams in different areas of the State respond to changes in nutrient concentrations; 5) determine the best regionalization scheme to describe the patterns in reference conditions and the responses in water quality and the biotic community; and 6) develop new indices to estimate nutrient concentrations in streams from a combination of biotic indices. The ultimate goal of this study is to provide the information needed to guide the development of regionally based nutrient criteria for Wisconsin streams. For total nitrogen (N) and suspended chlorophyll (SCHL) concentrations and water clarity, regional variability in reference conditions and in the responses in water quality to changes in land use are best described by subdividing wadeable streams into two categories: streams in areas with high clay-content soils (Environmental Phosphorus Zone 3, EPZ 3) and streams throughout the rest of the State. The regional variability in the response in total phosphorus (P) concentrations is also best described by subdividing the streams into these two categories; however, little consistent variability was found in reference P concentrations in streams throughout the State. Reference P concentrations are smilar throughout the State (0.03-0.04 mg/L). Reference N concentrations are divided into two categories: 0.6-0.7 mg/L in all streams except those in areas with high clay-content soils, where 0.4 mg/L is more appropriate. Reference SCHL concentrations are divided into two categories: 1.2-1.7 ?g/L in all streams except those in areas with high clay-content soils, where 1.0 ?g/L may be more appropriate. Reference water clarity is divided into two categories: streams in areas with high clay-content soils with a lower reference water clarity (Secchi tube depth, SD, of about 110 cm) and streams throughout the rest of the State (SD greater than or equal to about 115 cm). For each category of the biotic community (SCHL and benthic chlorophyll a concentrations (BCHL), periphytic diatoms, macroinvertebrates, and fish), a few biotic indices were more related to differences in nutrient concentrations than were others. For each of the indices more strongly related to nutrient concentrations, reference conditions were obtained by determining values corresponding to the worst 75th percentile value from a subset of minimally impacted streams (streams having reference nutrient concentrations). By examining the biotic community in streams having either reference P or N concentrations but not both, the relative importance of these two nutrients was determined. For SCHL, P was the more important limiting nutrient; however, for BCHL and all macroinvertebrate indices, it appears that N was the more important nutrient when concent

A global hotspot for dissolved organic carbon in hypermaritime watersheds of coastal British Columbia

NASA Astrophysics Data System (ADS)

Oliver, Allison A.; Tank, Suzanne E.; Giesbrecht, Ian; Korver, Maartje C.; Floyd, William C.; Sanborn, Paul; Bulmer, Chuck; Lertzman, Ken P.

2017-08-01

The perhumid region of the coastal temperate rainforest (CTR) of Pacific North America is one of the wettest places on Earth and contains numerous small catchments that discharge freshwater and high concentrations of dissolved organic carbon (DOC) directly to the coastal ocean. However, empirical data on the flux and composition of DOC exported from these watersheds are scarce. We established monitoring stations at the outlets of seven catchments on Calvert and Hecate islands, British Columbia, which represent the rain-dominated hypermaritime region of the perhumid CTR. Over several years, we measured stream discharge, stream water DOC concentration, and stream water dissolved organic-matter (DOM) composition. Discharge and DOC concentrations were used to calculate DOC fluxes and yields, and DOM composition was characterized using absorbance and fluorescence spectroscopy with parallel factor analysis (PARAFAC). The areal estimate of annual DOC yield in water year 2015 was 33.3 Mg C km-2 yr-1, with individual watersheds ranging from an average of 24.1 to 37.7 Mg C km-2 yr-1. This represents some of the highest DOC yields to be measured at the coastal margin. We observed seasonality in the quantity and composition of exports, with the majority of DOC export occurring during the extended wet period (September-April). Stream flow from catchments reacted quickly to rain inputs, resulting in rapid export of relatively fresh, highly terrestrial-like DOM. DOC concentration and measures of DOM composition were related to stream discharge and stream temperature and correlated with watershed attributes, including the extent of lakes and wetlands, and the thickness of organic and mineral soil horizons. Our discovery of high DOC yields from these small catchments in the CTR is especially compelling as they deliver relatively fresh, highly terrestrial organic matter directly to the coastal ocean. Hypermaritime landscapes are common on the British Columbia coast, suggesting that this coastal margin may play an important role in the regional processing of carbon and in linking terrestrial carbon to marine ecosystems.

Using T-RFLP data on denitrifier community composition to inform understanding of denitrification in stream sediments (Invited)

NASA Astrophysics Data System (ADS)

Wang, S.; Somers, K.; Sudduth, E.; Hassett, B.; Bernhardt, E. S.; Urban, D. L.

2010-12-01

We used terminal restriction fragment length polymorphism (T-RFLP), a molecular fingerprinting method, to characterize denitrifier communities in sediments taken from 48 study streams in North Carolina, USA. In addition to characterizing denitrifier communities, we also used denitrification enzyme activity (DEA) assays to measure potential denitrification rates. Due to differences in watershed land-use, study streams covered a gradient of nitrogen and carbon concentrations, as well as a gradient of contaminant loading from stormwater and sanitary sewers. Nitrogen and carbon (i.e., substrate) concentrations are commonly used to make predictions about denitrification rates in streams. Such models do not take into account denitrifier community composition, which may be an important, independent control of denitrification rates, particularly under stressful conditions (e.g., high contaminant loading) that prevent communities from capitalizing on high substrate availability. Our results indicate that substrate availability by itself was a weak predictor of denitrification rates; the same was also true for denitrifier community composition. However, when both factors were incorporated in a multiple regression model, the percent variation explained increased substantially. These findings suggest that T-RFLP, a relatively cost-effective method, can be used to improve our understanding of controls on denitrification rates in streams with varying watershed land-uses.

Trends in precipitation and stream-water chemistry in the northeastern United States, water years 1984-96

USGS Publications Warehouse

Clow, D.W.; Mast, M. Alisa

1999-01-01

Trends in precipitation and stream-water chemistry during water years 1984-96 were examined at eight precipitation monitoring sites and five nearby streams operated by the U.S. Geological Survey in the northeastern United States. The statistical analyses indicate the following: 1)Stream-water sulfate (SO4) concentrations decreased at seven of eight precipitation monitoring sites and in each of five streams. 2)Calcium plus magnesium (Ca + Mg) concentrations decreased at seven of eight precipitation monitoring sites and in three of five streams. 3)Precipitation acidity decreased at five of eight precipitation monitoring sites, but alkalinity increased in only one stream. These results indicate that decreases in atmospheric deposition of SO4 have resulted in decreased precipitation acidity. The chemical response of stream water to changes in precipitation chemistry was complex. Decreases in stream-water SO4 concentrations generally matched decreases of precipitation SO4. In stream water, increases in alkalinity were uncommon because decreases in SO4 concentrations often were accompanied by decreases in Ca + Mg concentrations. The decreases in Ca + Mg concentrations might be related to depletion of base cations from soil caused by long-term exposure to acidic deposition. Increases in streamwater alkalinity might not occur until rates of acidic deposition are reduced to substantially less than the rate of cation resupply by weathering and atmospheric deposition. In areas where forests are aggrading, recovery of stream-water alkalinity will be delayed further because of the acidifying effect of biomass accumulation.

Dissolved Solids in Streams of the Conterminous United States

NASA Astrophysics Data System (ADS)

Anning, D. W.; Flynn, M.

2014-12-01

Studies have shown that excessive dissolved-solids concentrations in water can have adverse effects on the environment and on agricultural, municipal, and industrial water users. Such effects motivated the U.S. Geological Survey's National Water-Quality Assessment Program to develop a SPAtially-Referenced Regression on Watershed Attributes (SPARROW) model to improve the understanding of dissolved solids in streams of the United States. Using the SPARROW model, annual dissolved-solids loads from 2,560 water-quality monitoring stations were statistically related to several spatial datasets serving as surrogates for dissolved-solids sources and transport processes. Sources investigated in the model included geologic materials, road de-icers, urban lands, cultivated lands, and pasture lands. Factors affecting transport from these sources to streams in the model included climate, soil, vegetation, terrain, population, irrigation, and artificial-drainage characteristics. The SPARROW model was used to predict long-term mean annual conditions for dissolved-solids sources, loads, yields, and concentrations in about 66,000 stream reaches and corresponding incremental catchments nationwide. The estimated total amount of dissolved solids delivered to the Nation's streams is 272 million metric tons (Mt) annually, of which 194 million Mt (71%) are from geologic sources, 38 million Mt (14%) are from road de-icers, 18 million Mt (7%) are from pasture lands, 14 million Mt (5 %) are from urban lands, and 8 million Mt (3%) are from cultivated lands. The median incremental-catchment yield delivered to local streams is 26 metric tons per year per square kilometer [(Mt/yr)/km2]. Ten percent of the incremental catchments yield less than 4 (Mt/yr)/km2, and 10 percent yield more than 90 (Mt/yr)/km2. In 13% of the reaches, predicted flow-weighted concentrations exceed 500 mg/L—the U.S. Environmental Protection Agency secondary non-enforceable drinking-water standard.

Occurrence and distribution of pesticide compounds in surface water of the Santa Ana basin, California, 1998-2001

USGS Publications Warehouse

Kent, Robert; Belitz, Kenneth; Altmann, Andrea J.; Wright, Michael T.; Mendez, Gregory O.

2005-01-01

A study of the occurrence and distribution of pesticide compounds in surface water of the highly urbanized Santa Ana Basin, California, was done as part of the U.S. Geological Survey's National Water-Quality Assessment Program (NAWQA). One-hundred and forty-eight samples were collected from 23 sites, and analyzed for pesticide compounds during the study period from November 1998 to September 2001. Sixty-six different pesticide compounds were detected at varying frequencies and concentrations, and one or more pesticides were detected in 92 percent of the samples. All pesticide concentrations were below maximum levels permitted in drinking water. However, two compounds-diazinon and diuron-exceeded nonenforceable drinking water health-advisory levels in at least one stream sample, and five compounds exceeded guidelines to protect aquatic life-carbaryl, chlorpyrifos, diazinon, lindane, and malathion. Twenty-two pesticide compounds were detected in at least 25 percent of the samples collected from any one fixed site. These are identified as 'major' pesticide compounds and are emphasized in this report. The degree to which pesticides were used in the basin, as well as their physical-chemical properties, are important explanatory factors in stream pesticide occurrence, and most pesticides probably enter streams with urban runoff. Stormflow substantially increases urban runoff, and storm effects on stream pesticide concentrations sometimes persist for several days or weeks after the storm. Water sources other than urban runoff also deliver pesticide compounds to surface water in the basin. For example, atrazine may enter streams in gaining reaches where ground water carries high loads as a result of historical use in the basin. Also, the data suggest that lindane, and perhaps bromacil, are present in treated wastewater, the predominant source of water to streams in the Santa Ana Basin.

Variability in stream chemistry in relation to urban development and biological condition in seven metropolitan areas of the United States, 1999-2004

USGS Publications Warehouse

Beaulieu, Karen M.; Bell, Amanda H.; Coles, James F.

2012-01-01

Beginning in 1999, the U.S. Geological Survey National Water Quality Assessment Program investigated the effects of urban development on stream ecosystems in nine metropolitan study areas across the United States. In seven of these study areas, stream-chemistry samples were collected every other month for 1 year at 6 to 10 sites. Within a study area, the sites collectively represented a gradient of urban development from minimally to highly developed watersheds, based on the percentage of urban land cover; depending on study area, the land cover before urban development was either forested or agricultural. The stream-chemistry factors measured in the samples were total nitrogen, total phosphorus, chloride, and pesticide toxicity. These data were used to characterize the stream-chemistry factors in four ways (hereafter referred to as characterizations)—seasonal high-flow value, seasonal low-flow value, the median value (representing a single integrated value of the factor over the year), and the standard deviation of values (representing the variation of the factor over the year). Aquatic macroinvertebrate communities were sampled at each site to infer the biological condition of the stream based on the relative sensitivity of the community to environmental stressors. A Spearman correlation analysis was used to evaluate relations between (1) urban development and each characterization of the stream-chemistry factors and (2) the biological condition of a stream and the different characterizations of chloride and pesticide toxicity. Overall, the study areas where the land cover before urban development was primarily forested had a greater number of moderate and strong relations compared with the study areas where the land cover before urban development was primarily agriculture; this was true when urban development was correlated with the stream-chemistry factors (except chloride) and when chloride and pesticide toxicity was correlated with the biological condition. Except for primarily phosphorus in two study areas, stream-chemistry factors generally increased with urban development, and among the different characterizations, the median value typically indicated the strongest relations. The variation in stream-chemistry factors throughout the year generally increased with urban development, indicating that water quality became less consistent as watersheds were developed. In study areas with high annual snow fall, the variation in chloride concentrations throughout the year was particularly strongly related to urban development, likely a result of road salt applications during the winter. The relations of the biological condition to chloride and pesticide toxicity were calculated irrespective of urban development, but the overall results indicated that the relations were still stronger in the study areas that had been forested before urban development. The weaker relations in the study areas that had been agricultural before urban development were likely the results of biological communities having been degraded from agricultural practices in the watersheds. Collectively, these results indicated that, compared with sampling a stream at a single point in time, sampling at regular intervals during a year may provide a more representative measure of water quality, especially in the areas of high urban development where water quality fluctuated more widely between samples. Furthermore, the use of "integrated" values of stream chemistry factors may be more appropriate when assessing relations to the biological condition of a stream because the taxa composition of a biological community typically reflects the water-quality conditions over time.

StreamVOC - A deterministic source-apportionment model to estimate volatile organic compound concentrations in rivers and streams

USGS Publications Warehouse

Asher, William E.; Bender, David A.; Zogorski, John S.; Bartholomay, Roy C.

2006-01-01

This report documents the construction and verification of the model, StreamVOC, that estimates (1) the time- and position-dependent concentrations of volatile organic compounds (VOCs) in rivers and streams as well as (2) the source apportionment (SA) of those concentrations. The model considers how different types of sources and loss processes can act together to yield a given observed VOC concentration. Reasons for interest in the relative and absolute contributions of different sources to contaminant concentrations include the need to apportion: (1) the origins for an observed contamination, and (2) the associated human and ecosystem risks. For VOCs, sources of interest include the atmosphere (by absorption), as well as point and nonpoint inflows of VOC-containing water. Loss processes of interest include volatilization to the atmosphere, degradation, and outflows of VOC-containing water from the stream to local ground water. This report presents the details of StreamVOC and compares model output with measured concentrations for eight VOCs found in the Aberjona River at Winchester, Massachusetts. Input data for the model were obtained during a synoptic study of the stream system conducted July 11-13, 2001, as part of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey. The input data included a variety of basic stream characteristics (for example, flows, temperature, and VOC concentrations). The StreamVOC concentration results agreed moderately well with the measured concentration data for several VOCs and provided compound-dependent SA estimates as a function of longitudinal distance down the river. For many VOCs, the quality of the agreement between the model-simulated and measured concentrations could be improved by simple adjustments of the model input parameters. In general, this study illustrated: (1) the considerable difficulty of quantifying correctly the locations and magnitudes of ground-water-related sources of contamination in streams; and (2) that model-based estimates of stream VOC concentrations are likely to be most accurate when the major sources are point sources or tributaries where the spatial extent and magnitude of the sources are tightly constrained and easily determined.

Occurrence and distribution of microbiological indicators in groundwater and stream water

USGS Publications Warehouse

Francy, D.S.; Helsel, D.R.; Nally, R.A.

2000-01-01

A total of 136 stream water and 143 groundwater samples collected in five important hydrologic systems of the United States were analyzed for microbiological indicators to test monitoring concepts in a nationally consistent program. Total coliforms were found in 99%, Escherichia coli in 97%, and Clostridium perfringens in 73% of stream water samples analyzed for each bacterium. Total coliforms were found in 20%, E. coli in less than 1%, and C. perfringens in none of the groundwater samples analyzed for each bacterium. Although coliphage analyses were performed on many of the samples, contamination in the laboratory and problems discerning discrete plaques precluded quantification. Land use was found to have the most significant effect on concentrations of bacterial indicators in stream water. Presence of septic systems on the property near the sampling site and well depth were found to be related to detection of coliforms in groundwater, although these relationships were not statistically significant. A greater diversity of sites, more detailed information about some factors, and a larger dataset may provide further insight to factors that affect microbiological indicators.

Foliar litter decomposition in an alpine forest meta-ecosystem on the eastern Tibetan Plateau.

PubMed

Yue, Kai; Yang, Wanqin; Peng, Changhui; Peng, Yan; Zhang, Chuan; Huang, Chunping; Tan, Yu; Wu, Fuzhong

2016-10-01

Litter decomposition is a biological process fundamental to element cycling and a main nutrient source within forest meta-ecosystems, but few studies have looked into this process simultaneously in individual ecosystems, where environmental factors can vary substantially. A two-year field study conducted in an alpine forest meta-ecosystem with four litter species (i.e., willow: Salix paraplesia, azalea: Rhododendron lapponicum, cypress: Sabina saltuaria, and larch: Larix mastersiana) that varied widely in chemical traits showed that both litter species and ecosystem type (i.e., forest floor, stream and riparian zone) are important factors affecting litter decomposition, and their effects can be moderated by local-scale environmental factors such as temperature and nutrient availability. Litter decomposed fastest in the streams followed by the riparian zone and forest floor regardless of species. For a given litter species, both the k value and limit value varied significantly among ecosystems, indicating that the litter decomposition rate and extent (i.e., reaching a limit value) can be substantially affected by ecosystem type and the local-scale environmental factors. Apart from litter initial acid unhydrolyzable residue (AUR) concentration and its ratio to nitrogen concentration (i.e., AUR/N ratio), the initial nutrient concentrations of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also important litter traits that affected decomposition depending on the ecosystem type. Copyright © 2016 Elsevier B.V. All rights reserved.

Water-Quality and Biological Characteristics and Responses to Agricultural Land Retirement in Three Streams of the Minnesota River Basin, Water Years 2006-08

USGS Publications Warehouse

Christensen, Victoria G.; Lee, Kathy E.; Sanocki, Christopher A.; Mohring, Eric H.; Kiesling, Richard L.

2009-01-01

Water-quality and biological characteristics in three streams in the Minnesota River Basin were assessed using data collected during water years 2006-08. The responses of nutrient concentrations, suspended-sediment concentrations, and biological characteristics to agricultural land retirement also were assessed. In general, total nitrogen, suspended-sediment, and chlorophyll-a concentrations, and fish resource quality improved with increasing land retirement. The Chetomba Creek, West Fork Beaver Creek, and South Branch Rush River subbasins, which range in size from about 200 to 400 square kilometers, have similar geologic and hydrologic settings but differ with respect to the amount, type, and location of retired agricultural land. Total nitrogen concentrations were largest, with a mean of 15.0 milligrams per liter (mg/L), in water samples from the South Branch Rush River, a subbasin with little to no agricultural land retirement; total nitrogen concentrations were smaller in samples from Chetomba Creek (mean of 10.6 mg/L) and West Fork Beaver Creek (mean of 7.9 mg/L), which are subbasins with more riparian or upland land retirement at the basin scale. Total phosphorus concentrations were not related directly to differing land-retirement percentages with mean concentrations at primary data-collection sites of 0.259 mg/L in the West Fork Beaver Creek subbasin, 0.164 mg/L in the Chetomba Creek subbasin, and 0.180 mg/L in the South Branch Rush River subbasin. Temporal variation in water quality was characterized using data from in-stream water-quality monitors and storm-sediment data. Fish data indicate better resource quality for the West Fork Beaver Creek subbasin than for other subbasins likely due to a combination of factors, including habitat quality, food resources, and dissolved oxygen characteristics. Index of biotic integrity (IBI) scores increased as local land-retirement percentages (within 50 and 100 meters of the streams) increased. Data and analysis from this study can be used to evaluate the success of agricultural management practices and land-retirement programs for improving stream quality.

Ammonia Monitor

NASA Technical Reports Server (NTRS)

Sauer, Richard L. (Inventor); Akse, James R. (Inventor); Thompson, John O. (Inventor); Atwater, James E. (Inventor)

1999-01-01

Ammonia monitor and method of use are disclosed. A continuous, real-time determination of the concentration of ammonia in an aqueous process stream is possible over a wide dynamic range of concentrations. No reagents are required because pH is controlled by an in-line solid-phase base. Ammonia is selectively transported across a membrane from the process stream to an analytical stream to an analytical stream under pH control. The specific electrical conductance of the analytical stream is measured and used to determine the concentration of ammonia.

Particle dispersing system and method for testing semiconductor manufacturing equipment

DOEpatents

Chandrachood, Madhavi; Ghanayem, Steve G.; Cantwell, Nancy; Rader, Daniel J.; Geller, Anthony S.

1998-01-01

The system and method prepare a gas stream comprising particles at a known concentration using a particle disperser for moving particles from a reservoir of particles into a stream of flowing carrier gas. The electrostatic charges on the particles entrained in the carrier gas are then neutralized or otherwise altered, and the resulting particle-laden gas stream is then diluted to provide an acceptable particle concentration. The diluted gas stream is then split into a calibration stream and the desired output stream. The particles in the calibration stream are detected to provide an indication of the actual size distribution and concentration of particles in the output stream that is supplied to a process chamber being analyzed. Particles flowing out of the process chamber within a vacuum pumping system are detected, and the output particle size distribution and concentration are compared with the particle size distribution and concentration of the calibration stream in order to determine the particle transport characteristics of a process chamber, or to determine the number of particles lodged in the process chamber as a function of manufacturing process parameters such as pressure, flowrate, temperature, process chamber geometry, particle size, particle charge, and gas composition.

An Analysis of Terrestrial and Aquatic Environmental Controls of Riverine Dissolved Organic Carbon in the Conterminous United States

DOE PAGES

Yang, Qichun; Zhang, Xuesong; Xu, Xingya; ...

2017-05-29

Riverine carbon cycling is an important, but insufficiently investigated component of the global carbon cycle. Analyses of environmental controls on riverine carbon cycling are critical for improved understanding of mechanisms regulating carbon processing and storage along the terrestrial-aquatic continuum. Here, we compile and analyze riverine dissolved organic carbon (DOC) concentration data from 1402 United States Geological Survey (USGS) gauge stations to examine the spatial variability and environmental controls of DOC concentrations in the United States (U.S.) surface waters. DOC concentrations exhibit high spatial variability, with an average of 6.42 ± 6.47 mg C/ L (Mean ± Standard Deviation). In general,more » high DOC concentrations occur in the Upper Mississippi River basin and the Southeastern U.S., while low concentrations are mainly distributed in the Western U.S. Single-factor analysis indicates that slope of drainage areas, wetlands, forests, percentage of first-order streams, and instream nutrients (such as nitrogen and phosphorus) pronouncedly influence DOC concentrations, but the explanatory power of each bivariate model is lower than 35%. Analyses based on the general multi-linear regression models suggest DOC concentrations are jointly impacted by multiple factors. Soil properties mainly show positive correlations with DOC concentrations; forest and shrub lands have positive correlations with DOC concentrations, but urban area and croplands demonstrate negative impacts; total instream phosphorus and dam density correlate positively with DOC concentrations. Notably, the relative importance of these environmental controls varies substantially across major U.S. water resource regions. In addition, DOC concentrations and environmental controls also show significant variability from small streams to large rivers, which may be caused by changing carbon sources and removal rates by river orders. In sum, our results reveal that general multi-linear regression analysis of twenty one terrestrial and aquatic environmental factors can partially explain (56%) the DOC concentration variation. In conclusion, this study highlights the complexity of the interactions among these environmental factors in determining DOC concentrations, thus calls for processes-based, non-linear methodologies to constrain uncertainties in riverine DOC cycling.« less

The contribution of wetlands to stream nitrogen load in the Loch Vale Watershed, Colorado, USA

USGS Publications Warehouse

Jian-hui, Huang; Baron, Jill S.; Binkley, Dan

1996-01-01

We explored the difference between the concentrations of different N forms and other chemical properties between stream water and riparian zone wetland soil water in the Loch Vale Watershed which is located on the eastern slope of the Continental Divide in Rocky Mountain National Park, Colorado, USA. The nitrate N concentration in stream water were significantly higher than in soil water of the three wetlands, while no significant difference appeared in ammonium N. The pH values were higher and conductivity values were lower in stream water than in wetland soil water. However, significant difference also appeared between nitrate N concentrations, pH and conductivity values in the water sampled from different positions of streams. The stream tributary water had higher nitrate N concentrations, higher pH and higher conducitity values. We also conducted experiments to compare the difference between the productivity, total N concentrations in biomass and soil of upper layers. At the end, we concluded that the wetlands distributed along the streams in Loch Vale Watershed had little effect on the nitrogen load of the stream water there.

Comparison of pesticide concentrations in streams at low flow in six metropolitan areas of the United States

USGS Publications Warehouse

Sprague, Lori A.; Nowell, Lisa H.

2008-01-01

To examine the effect of urban development on pesticide concentrations in streams under low-flow conditions, water samples were collected at stream sites along an urban land use gradient in six environmentally heterogeneous metropolitan areas of the United States. In all six metropolitan areas, total insecticide concentrations generally increased significantly as urban land cover in the basin increased, regardless of whether the background land cover in the basins was agricultural, forested, or shrub land. In contrast, the response of total herbicide concentrations to urbanization varied with the environmental setting. In the three metropolitan areas with predominantly forested background land cover (Raleigh-Durham, NC, USA; Atlanta, GA, USA; Portland, OR, USA), total herbicide concentrations increased significantly with increasing urban land cover. In contrast, total herbicide concentrations were not significantly related to urban land cover in the three remaining metropolitan areas, where total herbicide concentrations appeared to be strongly influenced by agricultural as well as urban sources (Milwaukee-Green Bay, WI, USA; Dallas-Fort Worth, TX, USA), or by factors not measured in the present study, such as water management (Denver, CO, USA). Pesticide concentrations rarely exceeded benchmarks for protection of aquatic life, although these low-flow concentrations are likely to be lower than at other times, such as during peak pesticide-use periods, storm events, or irrigation discharge. Normalization of pesticide concentrations by the pesticide toxicity index - an index of relative potential toxicity - for fish and cladocerans indicated that the pesticides detected at the highest concentrations (herbicides in five of the six metropolitan areas) were not necessarily the pesticides with the greatest potential to adversely affect aquatic life (typically insecticides such as carbaryl, chlorpyrifos, diazinon, and fipronil). ?? 2008 SETAC.

Perennial flow through convergent hillslopes explains chemodynamic solute behavior in a shale headwater catchment

NASA Astrophysics Data System (ADS)

Herndon, E.; Steinhoefel, G.; Dere, A. L. D.; Sullivan, P. L.

2017-12-01

Streams experience changing hydrologic connectivity to heterogeneous water sources under different flow regimes. It remains unclear how seasonal flow paths link these different sources and regulate concentration-discharge behavior. Previous research at the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) in central Pennsylvania, USA identified chemostatic solutes (e.g., K, Mg, Na, Cl) whose concentrations varied little across a wide range of discharge values and chemodynamic solutes (e.g., Fe and Mn) whose concentrations decreased sharply with increasing stream discharge. To elucidate inputs to the stream when concentrations of chemodynamic solutes were high, we investigated stream water and shallow groundwater (< 4 m) chemistry at the SSHCZO in early autumn when discharge was negligible. The stream consisted of isolated puddles that were chemically variable along the length of the channel but similar to underlying shallow groundwater. Chemodynamic solute concentrations in the stream and groundwater were high in the upper catchment but decreased by an order of magnitude towards the outlet. In contrast, chemostatic solute concentrations varied little. Groundwater was minimally connected to the stream in an area of upwelling near the stream headwaters; however, the water table remained over a meter below the stream bed along the rest of the channel. We conclude that well water sampled from the upper catchment is young, shallow interflow that upwells to generate metal-rich stream headwaters during the dry season. High concentrations of chemodynamic solutes measured during low discharge occur when metal-rich headwaters are flushed to the catchment outlet during periodic rain events. Interflow during the dry season originates from water that infiltrates through organic-rich swales; thus, metals in the stream at low flow are ultimately derived from convergent hillslopes where biological processes have concentrated chemodynamic elements. We infer that chemodynamic solutes are diluted at high discharge due to increased flow through planar hillslopes and inputs from regional groundwater that rises to enter the stream. This study highlights how spatially heterogeneous biogeochemistry and seasonally variable flow paths regulate concentration-discharge behavior within catchments.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for East Fork White River, Bartholomew County, Indiana

USGS Publications Warehouse

Wilber, William G.; Peters, James G.; Crawford, Charles G.

1979-01-01

A digital model calibrated to conditions in East Fork White River, Bartholomew County, IN, was used to develop alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. The model indicates that benthic-oxygen demand and the headwater concentrations of carbonaceous biochemical-oxygen demand, nitrogenous biochemical-oxygen demand, and dissolved oxygen are the most significant factors affecting the dissolved-oxygen concentration of East Fork White River downstream from the Columbus wastewater-treatment facility. The effect of effluent from the facility on the water quality of East Fork White River was minimal. The model also indicates that, with a benthic-oxygen demand of approximately 0.65 gram per square meter per day, the stream has no additional waste-load assimilative capacity during summer low flows. Regardless of the quality of the Columbus wastewater effluent, the minimum 24-hour average dissolved-oxygen concentration of at least 5 milligrams per liter, the State 's water-quality standard for streams, would not be met. Ammonia toxicity is not a limiting water-quality criterion during summer and winter low flows. During winter low flows, the current carbonaceous biochemical-oxygen demand limits for the Columbus wastewater-treatment facility will not result in violations of the in-stream dissolved-oxygen standard. (USGS)

An empirical method for estimating instream pre-mining pH and dissolved Cu concentration in catchments with acidic drainage and ferricrete

USGS Publications Warehouse

Nimick, D.A.; Gurrieri, J.T.; Furniss, G.

2009-01-01

Methods for assessing natural background water quality of streams affected by historical mining are vigorously debated. An empirical method is proposed in which stream-specific estimation equations are generated from relationships between either pH or dissolved Cu concentration in stream water and the Fe/Cu concentration ratio in Fe-precipitates presently forming in the stream. The equations and Fe/Cu ratios for pre-mining deposits of alluvial ferricrete then were used to reconstruct estimated pre-mining longitudinal profiles for pH and dissolved Cu in three acidic streams in Montana, USA. Primary assumptions underlying the proposed method are that alluvial ferricretes and modern Fe-precipitates share a common origin, that the Cu content of Fe-precipitates remains constant during and after conversion to ferricrete, and that geochemical factors other than pH and dissolved Cu concentration play a lesser role in determining Fe/Cu ratios in Fe-precipitates. The method was evaluated by applying it in a fourth, naturally acidic stream unaffected by mining, where estimated pre-mining pH and Cu concentrations were similar to present-day values, and by demonstrating that inflows, particularly from unmined areas, had consistent effects on both the pre-mining and measured profiles of pH and Cu concentration. Using this method, it was estimated that mining has affected about 480 m of Daisy Creek, 1.8 km of Fisher Creek, and at least 1 km of Swift Gulch. Mean values of pH decreased by about 0.6 pH units to about 3.2 in Daisy Creek and by 1-1.5 pH units to about 3.5 in Fisher Creek. In Swift Gulch, mining appears to have decreased pH from about 5.5 to as low as 3.6. Dissolved Cu concentrations increased due to mining almost 40% in Daisy Creek to a mean of 11.7 mg/L and as much as 230% in Fisher Creek to 0.690 mg/L. Uncertainty in the fate of Cu during the conversion of Fe-precipitates to ferricrete translates to potential errors in pre-mining estimates of as much as 0.25 units for pH and 22% for dissolved Cu concentration. The method warrants further testing in other mined and unmined watersheds. Comparison of pre-mining water-quality estimates derived from the ferricrete and other methods in single watersheds would be particularly valuable. The method has potential for use in monitoring remedial efforts at mine sites with ferricrete deposits. A reasonable remediation objective might be realized when the downstream pattern of Fe/Cu ratios in modern streambed Fe-precipitates corresponds to the pattern in pre-mining alluvial ferricrete deposits along a stream valley.

NITROUS OXIDE CONCENTRATIONS IN SMALL STREAMS OF THE GEORGIA PIEDMONT

EPA Science Inventory

We are measuring the dissolved nitrous oxide concentration in 17 headwater streams in the South Fork Broad River, Georgia watershed on a monthly basis. The selected small streams drain watersheds dominated by forest, pasture, developed, or mixed land uses. Nitrous oxide concentr...

Concentration-discharge relationships reflect chemostatic characteristics of US catchments

USGS Publications Warehouse

Godsey, S.E.; Kirchner, J.W.; Clow, D.W.

2009-01-01

Concentration-discharge relationships have been widely used as clues to the hydrochemical processes that control runoff chemistry. Here we examine concentration-discharge relationships for solutes produced primarily by mineral weathering in 59 geochemically diverse US catchments. We show that these catchments exhibit nearly chemostatic behaviour; their stream concentrations of weathering products such as Ca, Mg, Na, and Si typically vary by factors of only 3 to 20 while discharge varies by several orders of magnitude. Similar patterns are observed at the inter-annual time scale. This behaviour implies that solute concentrations in stream water are not determined by simple dilution of a fixed solute flux by a variable flux of water, and that rates of solute production and/or mobilization must be nearly proportional to water fluxes, both on storm and inter-annual timescales. We compared these catchments' concentration-discharge relationships to the predictions of several simple hydrological and geochemical models. Most of these models can be forced to approximately fit the observed concentration-discharge relationships, but often only by assuming unrealistic or internally inconsistent parameter values. We propose a new model that also fits the data and may be more robust. We suggest possible tests of the new model for future studies. The relative stability of concentration under widely varying discharge may help make aquatic environments habitable. It also implies that fluxes of weathering solutes in streams, and thus fluxes of alkalinity to the oceans, are determined primarily by water fluxes. Thus, hydrology may be a major driver of the ocean-alkalinity feedback regulating climate change. Copyright ?? 2009 John Wiley & Sons, Ltd.

Evaluation of the Accumulation of Trace Metals (as, U, CR, CU, PB, Zn) on Iron-Manganese Coatings on in Situ Stream Pebbles and Emplaced Substrates

NASA Astrophysics Data System (ADS)

Turpin, M. M.; Blake, J.; Crossey, L. J.; Ali, A.; Hansson, L.

2015-12-01

Exposure to trace metals (As, U, Cr, Cu, Pb, Zn) has potential negative health effects on human populations and wildlife. Geothermal waters often have elevated concentrations of trace elements and understanding the geochemical cycling of these elements can be challenging. Previous studies have utilized in situ stream pebbles and glass or ceramic substrates with iron-manganese oxide coatings to understand contamination and or chemical cycling. This project's main focus is to develop an ideal tracing method using adsorption onto substrate surfaces and to define key parameters that are necessary for the phenomenon of adsorption between trace metals and these surface coatings to occur. Sampling locations include the Jemez River and Rio San Antonio in the Jemez mountains, northern New Mexico. Both streams have significant geothermal inputs. Pebbles and cobbles were gathered from the active stream channel and 6mm glass beads and 2 X1 in. ceramic plates were placed in streams for three weeks to allow for coating accumulation. Factors such as leachate type, water pH, substrate type, coating accumulation period and leach time were all considered in this experiment. It was found that of the three leachates (aqua regia, 10% aqua regia and hydroxylamine), hydroxylamine was the most effective at leaching coatings without dissolving substrates. Samples leached with aqua regia and 10% aqua regia were found to lose weight and mass over the following 5, 7, and 10 day measurements. Glass beads were determined to be more effective than in stream pebbles as an accumulation substrate: coatings were more easily controlled and monitored. Samples leached with hydroxylamine for 5 hours and 72 hours showed little difference in their leachate concentrations, suggesting that leach time has little impact on the concentration of leachate samples. This research aims to find the best method for trace metal accumulation in streams to aid in understanding geochemical cycling.

Factors controlling mercury transport in an upland forested catchment

USGS Publications Warehouse

Scherbatskoy, T.; Shanley, J.B.; Keeler, G.J.

1998-01-01

Total mercury (Hg) deposition and input/output relationships were investigated in an 11-ha deciduous forested catchment in northern Vermont as part of ongoing evaluations of rig cycling and transport in the Lake Champlain basin. Atmospheric Hg deposition (precipitation + modeled vapor phase downward flux) was 425 mg ha-1 during the one-year period March 1994 through February 1995 and 463 mg ha-1 from March 1995 through February 1996. In the same periods, stream export of total Hg was 32 mg ha-1 and 22 mg ha-1, respectively. Thus, there was a net retention of Hg by the catchment of 92% the first year and 95% the second year. In the first year, 16.9 mg ha-1 or about half of the annual stream export, occurred on the single day of peak spring snowmelt in April. In contrast, the maximum daily export in the second year, when peak stream flow was somewhat lower, was 3.5 mg ha-1 during a January thaw. The fate of file Hg retained by this forested catchment is not known. Dissolved (< 0.22 ??m) Hg concentrations in stream water ranged from 0.5-2.6 ng L-1, even when total (unfiltered) concentrations were greater than 10 ng L-1 during high flow events. Total Hg concentrations in stream water were correlated with the total organic fraction of suspended sediment, suggesting the importance of organic material in Hg transport within the catchment. High flow events and transport with organic material may be especially important mechanisms for the movement of Hg through forested ecosystems.

Regional patterns of total nitrogen concentrations in the National Rivers and Streams Assessment

EPA Science Inventory

Patterns of nitrogen concentrations in streams sampled by the National Rivers and Streams Assessment (NRSA) were examined semi-quantitatively to identify regional differences in stream nitrogen levels. The data were categorized and analyzed by watershed size classes to reveal pat...

Pesticide data for selected Wyoming streams, 1976-78

USGS Publications Warehouse

Butler, David L.

1987-01-01

In 1976, the U.S. Geological Survey, in cooperation with the Wyoming Department of Agriculture, started a monitoring program to determine pesticide concentrations in Wyoming streams. This program was incorporated into the water-quality data-collection system already in operation. Samples were collected at 20 sites for analysis of various insecticides, herbicides, polychlorinated biphenyls, and polychlorinated napthalenes.\\The results through 1978 revealed small concentrations of pesticides in water and bottom-material samples were DDE (39 percent of the concentrations equal to or greater than the minimum reported concentrations of the analytical methods), DDD (20 percent), dieldrin (21 percent), and polychlorinated biphenyls (29 percent). The herbicides most commonly found in water samples were 2,4-D (29 percent of the concentrations equal to or greater than the minimum reported concentrations of the analytical method) and picloram (23 percent). Most concentrations were significantly less than concentrations thought to be harmful to freshwater aquatic life based on available toxicity data. However for some pesticides, U.S. Environmental Protection Agency water-quality criteria for freshwater aquatic life are based on bioaccumulation factors that result in criteria concentrations less than the minimum reported concentrations of the analytical methods. It is not known if certain pesticides were present at concentrations less than the minimum reported concentrations that exceeded these criteria.

Multivariate statistical techniques for the evaluation of surface water quality of the Himalayan foothills streams, Pakistan

NASA Astrophysics Data System (ADS)

Malik, Riffat Naseem; Hashmi, Muhammad Zaffar

2017-10-01

Himalayan foothills streams, Pakistan play an important role in living water supply and irrigation of farmlands; thus, the water quality is closely related to public health. Multivariate techniques were applied to check spatial and seasonal trends, and metals contamination sources of the Himalayan foothills streams, Pakistan. Grab surface water samples were collected from different sites (5-15 cm water depth) in pre-washed polyethylene containers. Fast Sequential Atomic Absorption Spectrophotometer (Varian FSAA-240) was used to measure the metals concentration. Concentrations of Ni, Cu, and Mn were high in pre-monsoon season than the post-monsoon season. Cluster analysis identified impaired, moderately impaired and least impaired clusters based on water parameters. Discriminant function analysis indicated spatial variability in water was due to temperature, electrical conductivity, nitrates, iron and lead whereas seasonal variations were correlated with 16 physicochemical parameters. Factor analysis identified municipal and poultry waste, automobile activities, surface runoff, and soil weathering as major sources of contamination. Levels of Mn, Cr, Fe, Pb, Cd, Zn and alkalinity were above the WHO and USEPA standards for surface water. The results of present study will help to higher authorities for the management of the Himalayan foothills streams.

Catchment influence on nitrate and dissolved organic matter in Alaskan streams across a latitudinal gradient

DOE PAGES

Harms, Tamara K.; Edmonds, Jennifer W.; Genet, Hélène; ...

2016-01-10

Spatial patterns in carbon (C) and nitrogen (N) cycles of high-latitude catchments have been linked to climate and permafrost and used to infer potential changes in biogeochemical cycles under climate warming. However, inconsistent spatial patterns across regions indicate that factors in addition to permafrost and regional climate may shape responses of C and N cycles to climate change. In this paper, we hypothesized that physical attributes of catchments modify responses of C and N cycles to climate and permafrost. We measured dissolved organic C (DOC) and nitrate (NO 3 ¯) concentrations, and composition of dissolved organic matter (DOM) in 21more » streams spanning boreal to arctic Alaska, and assessed permafrost, topography, and attributes of soils and vegetation as predictors of stream chemistry. Multiple regression analyses indicated that catchment slope is a primary driver, with lower DOC and higher NO 3 ¯ concentration in streams draining steeper catchments, respectively. Depth of the active layer explained additional variation in concentration of DOC and NO 3 ¯. Vegetation type explained regional variation in concentration and composition of DOM, which was characterized by optical methods. Composition of DOM was further correlated with attributes of soils, including moisture, temperature, and thickness of the organic layer. Finally, regional patterns of DOC and NO 3 ¯ concentrations in boreal to arctic Alaska were driven primarily by catchment topography and modified by permafrost, whereas composition of DOM was driven by attributes of soils and vegetation, suggesting that predicting changes to C and N cycling from permafrost-influenced regions should consider catchment setting in addition to dynamics of climate and permafrost.« less

Riparian and Associated Habitat Characteristics Related to Nutrient Concentrations and Biological Responses of Small Streams in Selected Agricultural Areas, United States, 2003-04

USGS Publications Warehouse

Zelt, Ronald B.; Munn, Mark D.

2009-01-01

Physical factors, including both in-stream and riparian habitat characteristics that limit biomass or otherwise regulate aquatic biological condition, have been identified by previous studies. However, linking the ecological significance of nutrient enrichment to habitat or landscape factors that could allow for improved management of streams has proved to be a challenge in many regions, including agricultural landscapes, where many ecological stressors are strong and the variability among watersheds typically is large. Riparian and associated habitat characteristics were sampled once during 2003-04 for an intensive ecological and nutrients study of small perennial streams in five contrasting agricultural landscapes across the United States to determine how biological communities and ecosystem processes respond to varying levels of nutrient enrichment. Nutrient concentrations were determined in stream water at two different sampling times per site and biological samples were collected once per site near the time of habitat characterization. Data for 141 sampling sites were compiled, representing five study areas, located in parts of the Delmarva Peninsula (Delaware and Maryland), Georgia, Indiana, Ohio, Nebraska, and Washington. This report examines the available data for riparian and associated habitat characteristics to address questions related to study-unit contrasts, spatial scale-related differences, multivariate correlation structure, and bivariate relations between selected habitat characteristics and either stream nutrient conditions or biological responses. Riparian and associated habitat characteristics were summarized and categorized into 22 groups of habitat variables, with 11 groups representing land-use and land-cover characteristics and 11 groups representing other riparian or in-stream habitat characteristics. Principal components analysis was used to identify a reduced set of habitat variables that describe most of the variability among the sampled sites. The habitat characteristics sampled within the five study units were compared statistically. Bivariate correlations between riparian habitat variables and either nutrient-chemistry or biological-response variables were examined for all sites combined, and for sites within each study area. Nutrient concentrations were correlated with the extent of riparian cropland. For nitrogen species, these correlations were more frequently at the basin scale, whereas for phosphorus, they were about equally frequent at the segment and basin scales. Basin-level extents of riparian cropland and reach-level bank vegetative cover were correlated strongly with both total nitrogen and dissolved inorganic nitrogen (DIN) among multiple study areas, reflecting the importance of agricultural land-management and conservation practices for reducing nitrogen delivery from near-stream sources. When sites lacking segment-level wetlands were excluded, the negative correlation of riparian wetland extent with DIN among 49 sites was strong at the reach and segment levels. Riparian wetland vegetation thus may be removing dissolved nutrients from soil water and shallow groundwater passing through riparian zones. Other habitat variables that correlated strongly with nitrogen and phosphorus species included suspended sediment, light availability, and antecedent water temperature. Chlorophyll concentrations in seston were positively correlated with phosphorus concentrations for all sites combined. Benthic chlorophyll was correlated strongly with nutrient concentrations in only the Delmarva study area and only in fine-grained habitats. Current velocity or hydraulic scour could explain correlation patterns for benthic chlorophyll among Georgia sites, whereas chlorophyll in seston was correlated with antecedent water temperature among Washington and Delmarva sites. The lack of any consistent correlation pattern between habitat characteristics and organic material density (ash-free dry mass)

Synthesis and Performance Evaluations of SAPO-34 Membranes- Milestone Report for FCRD-MRWFD-2016-000263

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhave, Ramesh R.; Jubin, Robert Thomas; Spencer, Barry B.

2016-07-01

This report describes the synthesis and evaluation of molecular sieve zeolite membranes to separate and concentrate tritiated water (HTO) from dilute HTO-bearing aqueous streams. Several silico alumino phosphate (SAPO-34) molecular sieve zeolite membranes were synthesized on tubular supports and characterized with gas and vapor permeation measurements. The pervaporation process performance was evaluated for the separation and concentration of tritiated water. Experiments were performed over a range of tritiated water concentration that correspond to the range anticipated in a nuclear fuel processing system that includes both acid and water streams recycling. The permeate was recovered under vacuum. The tritium concentration rangedmore » from 0.5 to 1 mCi/mL which is about 0.1 mg/L or 0.1 ppm. The separation factors calculated from the measured tritium concentrations ranged from 0.83-0.98. The HTO concentration was three orders of magnitude lower than prior experiments performed with simulated feed containing HDO (>100 ppm) using deuterated water where high separation factors (>10) were obtained using SAPO membranes on alumina disk supports. Although the membrane performance characterization results for HTO were lower than expected, they can be explained on the basis of low feed volume and three orders of magnitude lower HTO concentration compared to HDO concentration in deuterated water. Several new approaches are proposed, such as tuning the diffusion coefficient of HTO, and optimization of membrane thickness that may help achieve preferential transport of tritium (HTO) resulting in a substantially more concentrated permeate.« less

Water quality of streams and springs, Green River Basin, Wyoming

USGS Publications Warehouse

DeLong, L.L.

1986-01-01

Data concerning salinity, phosphorus, and trace elements in streams and springs within the Green River Basin in Wyoming are summarized. Relative contributions of salinity are shown through estimates of annual loads and average concentrations at 11 water quality measurements sites for the 1970-77 water years. A hypothetical diversion of 20 cu ft/sec from the Big Sandy River was found to lower dissolved solids concentration in the Green River at Green River, Wyoming. This effect was greatest during the winter months, lowering dissolved solids concentration as much as 13%. Decrease in dissolved solids concentrations during the remainder of the year was generally less than 2%. Unlike the dilution effect that overland runoff has on perennial streams, runoff in ephemeral and intermittent streams within the basin was found to be enriched by the flushing of salts from normally dry channels and basin surfaces. Relative concentrations of sodium and sulfate in streams within the basin appear to be controlled by solubility. A downstream trend of increasing relative concentrations of sodium, sulfate, or both with increasing dissolved solids concentration was evident in all streams sampled. Estimates of total phosphorus concentration at water quality measurement sites indicate that phosphorus is removed from the Green River water as it passes through Fontenelle and Flaming Gorge Reservoirs. Total phosphorus concentration at some stream sites is directly or inversely related to streamflow, but at most sites a simple relation between concentration and streamflow is not discernable. (USGS)

Assessing mercury exposure and effects to American dippers in headwater streams near mining sites.

PubMed

Henny, Charles J; Kaiser, James L; Packard, Heidi A; Grove, Robert A; Taft, Michael R

2005-10-01

To evaluate mercury (Hg) exposure and possible adverse effects of Hg on American dipper (Cinclus mexicanus) reproduction, we collected eggs and nestling feathers and the larval/nymph form of three Orders of aquatic macroinvertebrates (Ephemeroptera, Plecoptera and Trichoptera = EPT) important in their diet from three major headwater tributaries of the upper Willamette River, Oregon in 2002. The Coast Fork Willamette River is contaminated with Hg due to historical cinnabar (HgS) mining at the Black Butte Mine; the Row River is affected by past gold-mining operations located within the Bohemia Mining District, where Hg was used in the amalgamation process to recover gold; and the Middle Fork Willamette River is the reference area with no known mining. Methyl mercury (MeHg) concentrations (geometric mean) in composite EPT larvae (111.9 ng/g dry weight [dw] or 19.8 ng/g wet weight [ww]), dipper eggs (38.5 ng/g ww) and nestling feathers (1158 ng/g ww) collected from the Coast Fork Willamette were significantly higher than MeHg concentrations in EPT and dipper samples from other streams. Total mercury (THg) concentrations in surface sediments along the same Hg-impacted streams were investigated by others in 1999 (Row River tributaries) and 2002 (Coast Fork). The reported sediment THg concentrations paralleled our biological findings. Dipper breeding territories at higher elevations had fewer second clutches; however, dipper reproductive success along all streams (including the lower elevation and most Hg-contaminated Coast Fork), was judged excellent compared to other studies reviewed. Furthermore, MeHg concentrations in EPT samples from this study were well below dietary concentrations in other aquatic bird species, such as loons and ducks, reported to cause Hg-related reproductive problems. Our data suggest that either dipper feathers or EPT composites used to project MeHg concentrations in dipper feathers (with biomagnification factor of 10-20x) may be used, but with caution, to screen headwater streams for potential Hg-related effects on dippers. When actual feather concentrations or projected feather concentrations are equal to or lower than concentrations reported for the Coast Fork, dippers are expected to reproduce well (assuming adequate prey and suitable nest sites). When Hg concentrations are substantially higher, more detailed investigations may be required. Birds feeding almost exclusively on fish (e.g., osprey [Pandion haliaetus]) and usually found further downstream from the headwaters would not be adequately represented by dippers given the higher MeHg concentrations in fish resulting from biomagnification, compared to lower trophic level invertebrates.

Assessing mercury exposure and effects to American dippers in headwater streams near mining sites

USGS Publications Warehouse

Henny, Charles J.; Kaiser, James L.; Packard, Heidi A.; Grove, Robert A.; Taft, Mike R.

2005-01-01

To evaluate mercury (Hg) exposure and possible adverse effects of Hg on American dipper (Cinclus mexicanus) reproduction, we collected eggs and nestling feathers and the larval/nymph form of three Orders of aquatic macroinvertebrates (Ephemeroptera, Plecoptera and Trichoptera = EPT) important in their diet from three major headwater tributaries of the upper Willamette River, Oregon in 2002. The Coast Fork Willamette River is contaminated with Hg due to historical cinnabar (HgS) mining at the Black Butte Mine; the Row River is affected by past gold-mining operations located within the Bohemia Mining District, where Hg was used in the amalgamation process to recover gold; and the Middle Fork Willamette River is the reference area with no known mining. Methyl mercury (MeHg) concentrations (geometric mean) in composite EPT larvae (111.9 ng/g dry weight [dw] or 19.8 ng/g wet weight [ww]), dipper eggs (38.5 ng/g ww) and nestling feathers (1158 ng/g ww) collected from the Coast Fork Willamette were significantly higher than MeHg concentrations in EPT and dipper samples from other streams. Total mercury (THg) concentrations in surface sediments along the same Hg-impacted streams were investigated by others in 1999 (Row River tributaries) and 2002 (Coast Fork). The reported sediment THg concentrations paralleled our biological findings. Dipper breeding territories at higher elevations had fewer second clutches; however, dipper reproductive success along all streams (including the lower elevation and most Hg-contaminated Coast Fork), was judged excellent compared to other studies reviewed. Furthermore, MeHg concentrations in EPT samples from this study were well below dietary concentrations in other aquatic bird species, such as loons and ducks, reported to cause Hg-related reproductive problems. Our data suggest that either dipper feathers or EPT composites used to project MeHg concentrations in dipper feathers (with biomagnification factor of 10a??20??) may be used, but with caution, to screen headwater streams for potential Hg-related effects on dippers. When actual feather concentrations or projected feather concentrations are equal to or lower than concentrations reported for the Coast Fork, dippers are expected to reproduce well (assuming adequate prey and suitable nest sites). When Hg concentrations are substantially higher, more detailed investigations may be required. Birds feeding almost exclusively on fish (e.g., osprey [Pandion haliaetus]) and usually found further downstream from the headwaters would not be adequately represented by dippers given the higher MeHg concentrations in fish resulting from biomagnification, compared to lower trophic level invertebrates.

Accelerated Analyte Uptake on Single Beads in Microliter-scale Batch Separations using Acoustic Streaming: Plutonium Uptake by Anion Exchange for Analysis by Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paxton, Walter F.; O'Hara, Matthew J.; Peper, Shane M.

2008-06-01

The use of acoustic streaming as a non-contact mixing platform to accelerate mass transport-limited diffusion processes in small volume heterogeneous reactions has been investigated. Single bead anion exchange of plutonium at nanomolar and sub-picomolar concentrations in 20 microliter liquid volumes was used to demonstrate the effect of acoustic mixing. Pu uptake rates on individual ~760 micrometer diameter AG 1x4 anion exchange resin beads were determined using acoustic mixing and compared with Pu uptake rates achieved by static diffusion alone. An 82 MHz surface acoustic wave (SAW) device was placed in contact with the underside of a 384-well microplate containing flat-bottomedmore » semiconical wells. Acoustic energy was coupled into the solution in the well, inducing acoustic streaming. Pu uptake rates were determined by the plutonium remaining in solution after specific elapsed time intervals, using liquid scintillation counting (LSC) for nanomolar concentrations and thermal ionization mass spectrometry (TIMS) analysis for the sub-picomolar concentration experiments. It was found that this small batch uptake reaction could be accelerated by a factor of about five-fold or more, depending on the acoustic power applied.« less

Assessment of elemental concentrations in streams of the New Lead Belt in southeastern Missouri, 2002-05

USGS Publications Warehouse

Brumbaugh, William G.; May, Thomas W.; Besser, John M.; Allert, Ann L.; Schmitt, Christopher J.

2007-01-01

Concerns about possible effects of lead-mining activities on the water quality of federally protected streams located in southeastern Missouri prompted a suite of multidisciplinary studies to be conducted by the U.S. Geological Survey. As part of this investigation, a series of biological studies were initiated in 2001 for streams in the current mining region and the prospecting area. In this report, results are examined for trace elements and other selected chemical measurements in sediment, surface water, and sediment interstitial (pore) water sampled between 2002 and 2005 in association with these biological studies. Compared to reference sites, fine sediments collected downstream from mining areas were enriched in metals by factors as large as 75 for cadmium, 62 for cobalt, 171 for nickel, 95 for lead, and 150 for zinc. Greatest metal concentrations in sediments collected in 2002 were from sites downstream from mines on Strother Creek, Courtois Creek, and the West Fork Black River. Sediments from sites on Bee Fork, Logan Creek, and Sweetwater Creek also were noticeably enriched in lead. Sediments in Clearwater Lake, at least 75 kilometers downstream from mining activity, had metal concentrations that were 1.5 to 2.1 times greater than sediments in an area of the lake with no upstream mining activity. Longitudinal sampling along three streams in 2004 indicated that sediment metal concentrations decreased considerably a few kilometers downstream from mining activities; however, in Strother Creek some metals were still enriched by a factor of five or more as far as 13 kilometers downstream from the Buick tailings impoundment. Compared with 2002 samples, metals concentrations were dramatically lower in sediments collected in 2004 at an upper West Fork Black River site, presumably because beneficiation operations at the West Fork mill ceased in 2000. Concentrations of metals and sulfate in sediment interstitial (pore) waters generally tracked closely with metal concentrations in sediments. Metals, including cobalt, nickel, lead, and zinc, were elevated substantially in laboratory-produced pore waters of fine sediments collected near mining operations in 2002 and 2004. Passive diffusion samplers (peepers) buried 4 to 6 centimeters deep in riffle-run stream sediments during 2003 and 2005 had much lower pore-water metal concentrations than the laboratory-produced pore waters of fine sediments collected in 2002 and 2004, but each sampling method produced similar patterns among sites. The combined mean concentration of lead in peeper samples from selected sites located downstream from mining activities for six streams was about 10-fold greater than the mean of the reference sites. In most instances, metals concentrations in surface water and peeper water were not greatly different, indicating considerable exchange between the surface water and pore water at the depths and locations where peepers were situated. Passive sampling probes used to assess metal lability in pore waters of selected samples during 2004 sediment toxicity tests indicated that most of the filterable lead in the laboratory-prepared pore water was relatively non-labile, presumably because lead was complexed by organic matter, or was present as colloidal species. In contrast, large percentages of cobalt and nickel in pore water appeared to be labile. Passive integrative samplers deployed in surface water for up to 3 weeks at three sites in July 2005 confirmed the presence of elevated concentrations of labile metals downstream from mining operations on Strother Creek and, to a lesser extent, Bee Fork. These samplers also indicated a considerable increase in metal loadings occurred for a few days at the Strother Creek site, which coincided with moderate increases in stream discharges in the area.

Application of Integral Pumping Tests to estimate the influence of losing streams on groundwater quality

NASA Astrophysics Data System (ADS)

Leschik, S.; Musolff, A.; Reinstorf, F.; Strauch, G.; Schirmer, M.

2009-05-01

Urban streams receive effluents of wastewater treatment plants and untreated wastewater during combined sewer overflow events. In the case of losing streams substances, which originate from wastewater, can reach the groundwater and deteriorate its quality. The estimation of mass flow rates Mex from losing streams to the groundwater is important to support groundwater management strategies, but is a challenging task. Variable inflow of wastewater with time-dependent concentrations of wastewater constituents causes a variable water composition in urban streams. Heterogeneities in the structure of the streambed and the connected aquifer lead, in combination with this variable water composition, to heterogeneous concentration patterns of wastewater constituents in the vicinity of urban streams. Groundwater investigation methods based on conventional point sampling may yield unreliable results under these conditions. Integral Pumping Tests (IPT) can overcome the problem of heterogeneous concentrations in an aquifer by increasing the sampled volume. Long-time pumping (several days) and simultaneous sampling yields reliable average concentrations Cav and mass flow rates Mcp for virtual control planes perpendicular to the natural flow direction. We applied the IPT method in order to estimate Mex of a stream section in Leipzig (Germany). The investigated stream is strongly influenced by combined sewer overflow events. Four pumping wells were installed up- and downstream of the stream section and operated for a period of five days. The study was focused on four inorganic (potassium, chloride, nitrate and sulfate) and two organic (caffeine and technical-nonylphenol) wastewater constituents with different transport properties. The obtained concentration-time series were used in combination with a numerical flow model to estimate Mcp of the respective wells. The difference of the Mcp's between up- and downstream wells yields Mex of wastewater constituents that increase downstream of the stream. In order to confirm the obtained Mcp's concentrations of additional measurements in the investigated stream were compared with the concentrations in the groundwater up- and downstream of the stream section. The results revealed increased Mcp's downstream of the stream section for chloride, potassium and nitrate, whereas Mcp of sulfate was decreased. Micropollutants caffeine and technical-nonylphenol showed decreased Mcp's downstream of the stream section in 75 % of the cases. Values of Mex could only be given for chloride, potassium, nitrate and caffeine. The comparison of concentrations in the stream with those in the groundwater points to the streambed as a zone where mass accumulation and degradation processes occur. The obtained results imply that the applied method can provide reliable data about the influence of losing streams on groundwater quality.

Effect of land use and hydrological processes on Escherichia coli concentrations in streams of tropical, humid headwater catchments

PubMed Central

Rochelle-Newall, Emma J.; Ribolzi, Olivier; Viguier, Marion; Thammahacksa, Chanthamousone; Silvera, Norbert; Latsachack, Keooudone; Dinh, Rinh Pham; Naporn, Piyapong; Sy, Hai Tran; Soulileuth, Bounsamay; Hmaimum, Nikom; Sisouvanh, Pem; Robain, Henri; Janeau, Jean-Louis; Valentin, Christian; Boithias, Laurie; Pierret, Alain

2016-01-01

Lack of access to clean water and adequate sanitation continues to be a major brake on development. Here we present the results of a 12-month investigation into the dynamics of Escherichia coli, a commonly used indicator of faecal contamination in water supplies, in three small, rural catchments in Laos, Thailand and Vietnam. We show that land use and hydrology are major controlling factors of E. coli concentrations in streamwater and that the relative importance of these two factors varies between the dry and wet seasons. In all three catchments, the highest concentrations were observed during the wet season when storm events and overland flow were highest. However, smaller peaks of E. coli concentration were also observed during the dry season. These latter correspond to periods of intense farming activities and small, episodic rain events. Furthermore, vegetation type, through land use and soil surface crusting, combined with mammalian presence play an important role in determining E. coli loads in the streams. Finally, sampling during stormflow revealed the importance of having appropriate sampling protocols if information on maximum contamination levels is required as grab sampling at a fixed time step may miss important peaks in E. coli numbers. PMID:27604854

Soil and groundwater attenuation factors for nitrogen from septic systems in the Chesapeake Bay TMDL

NASA Astrophysics Data System (ADS)

Radcliffe, D. E.; Geza, M.; O'Drisoll, M.; Humphrey, C., Jr.

2015-12-01

An expert panel was tasked with estimating the percent of the nitrogen (N) load from septic systems that was lost in the flow path from a typical home to third-order streams as part of the Chesapeake Bay Total Maximum Daily Load (TMDL). These losses were referred to as attenuation factors. We developed values for the soil (unsaturated) zone and for the Piedmont and Coastal Plain groundwater zones. For the soil zone, we used the Soil Treatment Unit MODel (STUMOD) to estimate loses due to denitrification for all 12 soil textural classes and then averaged the results over three textural groups. Assuming hydraulic loading at the design rate and a conventional system, the attenuation factors were 16% for sand, loamy sand, sandy loam, and loam soils; 34% for silt loam, clay loam, sandy clay loam, silty clay loam, and silt soils; and 54% for sandy clay, silty clay, and clay soils. Attenuation factors increased in the more clayey soils due to wetter conditions and more losses due to denitrification. Attenuation factors were also developed for reduced hydraulic loading rates and for systems using advanced N pre-treatment. For the Piedmont groundwater zone, we used data from a recent study in Georgia of small suburban streams with high-density septic systems. Stream base-flow load was estimated using simultaneous measurements of total N concentration and discharge and compared to the estimated groundwater input load, resulting in an attenuation factor of 81%. For the Coastal Plain groundwater zone, literature values of groundwater N concentrations within septic system plumes in Virginia, North Carolina, and Florida were used to estimate an attenuation factor of approximately 60% at 100m downgradient from the drainfield. These attenuation factors will be used to estimate the contribution of N to the Chesapeake Bay in the Phase 6 TMDL models.

Arsenic in the health of ecosystems: spatial distribution in water, sediment and aquatic biota of Pampean streams.

PubMed

Rodríguez Castro, M C; Marcó P, L; Ranieri, M C; Vázquez, C; Giorgi, A

2017-10-07

A survey of arsenic and phosphorus in Pampean streams of Buenos Aires province was performed. Nitrates and ammonia were also determined. Stream water was sampled as well as stream sediment and filamentous algae. Results show that 32 streams exceeded the arsenic recommended guidelines for human consumption of 10 μg L -1 and six exceeded recommended values for aquatic organisms' protection of 50 μg L -1 . The average concentration found was 36.54 μg L -1 and areas with more concentration of As are located in the southern region of the province, in streams that are tributaries of the Atlantic Ocean. Other regions with high As concentration are the Matanza River tributaries and the Arrecifes River tributaries. No differences of As concentration was found between stream sediments. Also, no seasonal pattern of As concentration was observed in one stream sampled during a year, but a positive correlation between As and the conductivity (p = 0.0002) and pH (p = 0.01) of the streams was found. Also, As bioaccumulation was detected for all the algae sampled, but no correlation between As accumulated and As in the stream water was found. Ammonia levels exceeded recommended guidelines for human consumption in the Argentinean law in 30 streams. The characterization performed in this study provides relevant information on the distribution of arsenic and its origin and mobility.

Norm removal from frac water

DOEpatents

Silva, James Manio; Matis, Hope; Kostedt, IV, William Leonard

2014-11-18

A method for treating low barium frac water includes contacting a frac water stream with a radium selective complexing resin to produce a low radium stream, passing the low radium stream through a thermal brine concentrator to produce a concentrated brine; and passing the concentrated brine through a thermal crystallizer to yield road salt.

User's manual for the Graphical Constituent Loading Analysis System (GCLAS)

USGS Publications Warehouse

Koltun, G.F.; Eberle, Michael; Gray, J.R.; Glysson, G.D.

2006-01-01

This manual describes the Graphical Constituent Loading Analysis System (GCLAS), an interactive cross-platform program for computing the mass (load) and average concentration of a constituent that is transported in stream water over a period of time. GCLAS computes loads as a function of an equal-interval streamflow time series and an equal- or unequal-interval time series of constituent concentrations. The constituent-concentration time series may be composed of measured concentrations or a combination of measured and estimated concentrations. GCLAS is not intended for use in situations where concentration data (or an appropriate surrogate) are collected infrequently or where an appreciable amount of the concentration values are censored. It is assumed that the constituent-concentration time series used by GCLAS adequately represents the true time-varying concentration. Commonly, measured constituent concentrations are collected at a frequency that is less than ideal (from a load-computation standpoint), so estimated concentrations must be inserted in the time series to better approximate the expected chemograph. GCLAS provides tools to facilitate estimation and entry of instantaneous concentrations for that purpose. Water-quality samples collected for load computation frequently are collected in a single vertical or at single point in a stream cross section. Several factors, some of which may vary as a function of time and (or) streamflow, can affect whether the sample concentrations are representative of the mean concentration in the cross section. GCLAS provides tools to aid the analyst in assessing whether concentrations in samples collected in a single vertical or at single point in a stream cross section exhibit systematic bias with respect to the mean concentrations. In cases where bias is evident, the analyst can construct coefficient relations in GCLAS to reduce or eliminate the observed bias. GCLAS can export load and concentration data in formats suitable for entry into the U.S. Geological Survey's National Water Information System. GCLAS can also import and export data in formats that are compatible with various commonly used spreadsheet and statistics programs.

Associations between iron concentration and productivity in montane streams of the Black Hills, South Dakota

USGS Publications Warehouse

Hayer, Cari Ann; Holcomb, Benjamin M.; Chipps, Steven R.

2013-01-01

Iron is an important micronutrient found in aquatic systems that can influence nutrient availability (e.g., phosphorus) and primary productivity. In streams, high iron concentrations often are associated with low pH as a result of acid mine drainage, which is known to affect fish and invertebrate communities. Streams in the Black Hills of South Dakota are generally circumneutral in pH, yet select streams exhibit high iron concentrations associated with natural iron deposits. In this study, we examined relationships among iron concentration, priphyton biomass, macroinvertebrate abundance, and fish assemblages in four Black Hills streams. The stream with the highest iron concentration (~5 mg Fe/L) had reduced periphyton biomass, invertebrate abundance, and fish biomass compared to the three streams with lower iron levels (0.1 to 0.6 mg Fe/L). Reduced stream productivity was attributed to indirect effects of ferric iron Fe+++), owing to iron-hydroxide precipitation that influenced habitat quality (i.e., substrate and turbidity) and food availability (periphyton and invertebrates) for higher trophic levels (e.g., fish). Additionally, reduced primary and secondary production was associated with reduced standing stocks of salmonid fishes. Our findings suggested that naturally occurring iron deposits may constrain macroinvertebrate and fish production.

Geochemical Differences between two adjacent streams in the Tenaya Lake region of Yosemite National Park

NASA Astrophysics Data System (ADS)

Antweiler, R.; Andrews, E. D.

2010-12-01

Tenaya and Murphy Creeks are two small, intermittent streams with drainage basins adjacent to each other in the Tenaya Lake region of Yosemite National Park. Tenaya Creek has a drainage basin area of 3.49 km2 ranging in elevation from 2491 to 3012 m; Murphy Creek has a drainage basin size of 7.07 km2 ranging in elevation from 2485 to 2990 m. Both basins are underlain by the Half Dome and Cathedral Peak Granodiorites (Bateman et al, 1983), with chemical compositions that are practically indistinguishable (Bateman et al, 1988). Both streams derive all of their water from snowmelt and rainfall, normally going dry by early August each year. Tenaya Creek flows primarily south-southwest, whereas Murphy Creek predominantly flows south. For nearly all of Tenaya Creek’s length it is bordered by the Tioga Pass Road, the only highway in Yosemite National Park which crosses the Sierras; on the other hand, all of Murphy Creek (except its mouth) is wilderness. During the summers of 2009 and 2010, both creeks were sampled along most of their lengths for major and trace elements. In addition, both streams have been sampled near their mouths periodically during the spring and summer (until they go dry) since 2007. Water discharge has been continuously monitored during this time. Because these streams derive all of their water from snowmelt and rainfall, the water chemistry of each must originate from atmospheric deposition, weathering of the bedrock and/or human or animal inputs. These factors, along with the similarity of the geology, topography and basin orientation, suggest that the water chemistries of the creeks should be similar. Instead, while measured sulfate concentrations in Tenaya and Murphy Creeks are similar in their upper reaches, Tenaya Creek sulfate values are almost double in the lower reaches. No other major or trace element showed a similar pattern, although sodium, potassium, calcium and rubidium showed modest increases. Other concentration differences between the two streams were mostly in magnitude rather than in downstream trends. For example, concentrations of beryllium, cobalt, lithium, niobium, silica and the rare earth elements (REE) were uniformly higher in Tenaya Creek whereas concentrations of iodide, molybdenum, tellurium, and tungsten were higher in Murphy Creek. During each water year, chloride concentrations increase as discharge decreases in both streams, a pattern seen for most elements. In contrast, aluminum, niobium, thorium and the REE decrease with decreasing flow for both streams, indicating that basin export of these is dominated by snowmelt runoff. Although most chemical constituents show similar patterns between drainages over the course of a water year, sulfate is exceptional: concentrations tend to decrease with decreasing flow in Murphy Creek, whereas sulfate increases at a greater rate than does chloride in Tenaya Creek.

Urban stormwater runoff drives denitrifying community composition through changes in sediment texture and carbon content.

PubMed

Perryman, Shane E; Rees, Gavin N; Walsh, Christopher J; Grace, Michael R

2011-05-01

The export of nitrogen from urban catchments is a global problem, and denitrifying bacteria in stream ecosystems are critical for reducing in-stream N. However, the environmental factors that control the composition of denitrifying communities in streams are not well understood. We determined whether denitrifying community composition in sediments of nine streams on the eastern fringe of Melbourne, Australia was correlated with two measures of catchment urban impact: effective imperviousness (EI, the proportion of a catchment covered by impervious surfaces with direct connection to streams) or septic tank density (which affects stream water chemistry, particularly stream N concentrations). Denitrifying community structure was examined by comparing terminal restriction fragment length polymorphisms of nosZ genes in the sediments, as the nosZ gene codes for nitrous oxide reductase, the last step in the denitrification pathway. We also determined the chemical and physical characteristics of the streams that were best correlated with denitrifying community composition. EI was strongly correlated with community composition and sediment physical and chemical properties, while septic tank density was not. Sites with high EI were sandier, with less fine sediment and lower organic carbon content, higher sediment cations (calcium, sodium and magnesium) and water filterable reactive phosphorus concentrations. These were also the best small-scale environmental variables that explained denitrifying community composition. Among our study streams, which differed in the degree of urban stormwater impact, sediment grain size and carbon content are the most likely drivers of change in community composition. Denitrifying community composition is another in a long list of ecological indicators that suggest the profound degradation of streams is caused by urban stormwater runoff. While the relationships between denitrifying community composition and denitrification rates are yet to be unequivocally established, landscape-scale indices of environmental impact such as EI may prove to be useful indicators of change in microbial communities.

Dissolved black carbon in grassland streams: is there an effect of recent fire history?

PubMed

Ding, Yan; Yamashita, Youhei; Dodds, Walter K; Jaffé, Rudolf

2013-03-01

While the existence of black carbon as part of dissolved organic matter (DOM) has been confirmed, quantitative determinations of dissolved black carbon (DBC) in freshwater ecosystem and information on factors controlling its concentration are scarce. In this study, stream surface water samples from a series of watersheds subject to different burn frequencies in Konza Prairie (Kansas, USA) were collected in order to determine if recent fire history has a noticeable effect on DBC concentration. The DBC levels detected ranged from 0.04 to 0.11 mg L(-1), accounting for ca. 3.32±0.51% of dissolved organic carbon (DOC). No correlation was found between DBC concentration and neither fire frequency nor time since last burn. We suggest that limited DBC flux is related to high burning efficiency, possibly greater export during periods of high discharge and/or the continuous export of DBC over long time scales. A linear correlation between DOC and DBC concentrations was observed, suggesting the export mechanisms determining DOC and DBC concentrations are likely coupled. The potential influence of fire history was less than the influence of other factors controlling the DOC and DBC dynamics in this ecosystem. Assuming similar conditions and processes apply in grasslands elsewhere, extrapolation to a global scale would suggest a global grasslands flux of DBC on the order of 0.14 Mt carbon year(-1). Copyright © 2012 Elsevier Ltd. All rights reserved.

Traveltime and longitudinal dispersion in Illinois streams

USGS Publications Warehouse

Graf, J.B.

1984-01-01

Twenty-seven measurements of traveltime and longitudinal dispersion in 10 Illinois streams provide data needed for estimating traveltime of peak concentration of a conservative solute, traveltime of the leading edge of a solute cloud, peak concentration resulting from a given quantity of solute, and passage time of solute past a given point on a stream for both measured and unmeasured streams. Traveltime of peak concentration and of the leading edge of the cloud are related to discharge at the downstream end of the reach, distance of travel, and the fraction of the time that discharge at a given location on the stream is equaled or exceeded. Peak concentration and passage time are best estimated from the relation of each to traveltime. In measured streams, dispersion efficiency is greater than that predicted by Fickian diffusion theory. The rate of decrease in peak concentration with traveltime is about equal to the rate of increase in passage time. Average velocity in a stream reach, given by the velocity of the center of solute mass in that reach, also can be estimated from an equation developed from measured values. (USGS)

Identifying sources of stream water sulfate after a summer drought in the Sleepers River watershed (Vermont, USA) using hydrological, chemical, and isotopic techniques

USGS Publications Warehouse

Mayer, B.; Shanley, J.B.; Bailey, S.W.; Mitchell, M.J.

2010-01-01

In many forested headwater catchments, peak SO42 - concentrations in stream water occur in the late summer or fall following drought potentially resulting in episodic stream acidification. The sources of highly elevated stream water SO42 - concentrations were investigated in a first order stream at the Sleepers River watershed (Vermont, USA) after the particularly dry summer of 2001 using a combination of hydrological, chemical and isotopic approaches. Throughout the summer of 2001 SO42 - concentrations in stream water doubled from ???130 to 270 ??eq/L while flows decreased. Simultaneously increasing Na+ and Ca2+ concentrations and ??34S values increasing from +7??? towards those of bedrock S (???+10.5???) indicated that chemical weathering involving hydrolysis of silicates and oxidation of sulfide minerals in schists and phyllites was the cause for the initial increase in SO42 - concentrations. During re-wetting of the watershed in late September and early October of 2001, increasing stream flows were accompanied by decreasing Na+ and Ca2+ concentrations, but SO42 - concentrations continued to increase up to 568 ??eq/L, indicating that a major source of SO42 - in addition to bedrock weathering contributed to peak SO42 - concentrations. The further increase in SO42 - concentrations coincided with an abrupt decrease of ??34S values in stream water SO42 - from maximum values near +10??? to minimum values near -3???. Soil investigations revealed that some C-horizons in the Spodsols of the watershed contained secondary sulfide minerals with ??34S values near -22???. The shift to negative ??34S values of stream water SO42 - indicates that secondary sulfides in C-horizons were oxidized to SO42 - during the particularly dry summer of 2001. The newly formed SO42 - was transported to the streams during re-wetting of the watershed contributing ???60% of the SO42 - during peak concentrations in the stream water. Thereafter, the contribution of SO42 - from oxidation of secondary sulfides in C-horizons decreased rapidly and pedogenic SO42 - reemerged as a dominant SO42 - source in concert with decreasing SO42 - concentrations in spring of 2002. The study provides evidence that a quantitative assessment of the sources of stream water SO42 - in forested watersheds is possible by combining hydrological, chemical and isotopic techniques, provided that the isotopic compositions of all potential SO42 - sources are distinctly different. ?? 2010 Elsevier Ltd.

A Review of Semivolatile and Volatile Organic Compounds in Highway Runoff and Urban Stormwater

USGS Publications Warehouse

Lopes, Thomas J.; Dionne, Shannon G.

1998-01-01

Many studies have been conducted since 1970 to characterize concentrations of semivolatile organic compounds (SVOCs) in highway runoff and urban stormwater. To a lesser extent, studies also have characterized concentrations of volatile organic compounds (VOCs), estimated loads of SVOCs, and assessed potential impacts of these contaminants on receiving streams. This review evaluates the quality of existing data on SVOCs and VOCs in highway runoff and urban storm- water and summarizes significant findings. Studies related to highways are emphasized when possible. The review included 44 articles and reports that focused primarily on SVOCs and VOCs. Only 17 of these publications are related to highways, and 5 of these 17 are themselves review papers. SVOCs in urban stormwater and sediments during the late 1970's to mid-1980's were the subject of most studies. Criteria used to evaluate data quality included documentation of sampling protocols, analytical methods, minimum reporting limit (MRL) or method detection limit (MDL), qualityassurance protocols, and quality-control samples. The largest deficiency in documenting data quality was that only 10 percent of the studies described where water samples were collected in the stream cross section. About 80 percent of SVOCs in runoff are in the suspended solids. Because suspended solids can vary significantly even in narrow channels, concentrations from discrete point samples and contaminant loads estimated from those samples are questionable without information on sample location or how well streamflow was mixed. Thirty percent or fewer of the studies documented the MRL, MDL, cleaning of samplers, or use of field quality-control samples. Comparing results of different studies and evaluating the quality of environmental data, especially for samples with low concentrations, is difficult without this information. The most significant factor affecting SVOC concentrations in water is suspended solids concentration. In sediment, the most significant factors affecting SVOC concentrations are organic carbon content and distance from sources such as highways and power plants. Petroleum hydrocarbons, oil and grease, and polycyclic aromatic hydrocarbons (PAHs) in crankcase oil and vehicle emissions are the major SVOCs detected in highway runoff and urban stormwater. The few loading factors and regression equations that were developed in the 1970's and 1980's have limited use in estimating current (1998) loads of SVOCs on a national scale. These factors and equations are based on few data and use inconsistent units, and some are independent of rainfall. Also, more cars on the road today have catalytic converters, and fuels that were used in 1998 are cleaner than when loading factors and regression equations were developed. Comparisons to water-quality and sedimentquality criteria and guidelines indicate that PAHs, phenolic compounds, and phthalates in runoff and sediment exceeded U.S. Environmental Protection Agency drinking-water and aquatic-life standards and guidelines. PAHs in stream sediments adjacent to highways have the highest potential for adverse effects on receiving streams. Few data exist on VOCs in highway runoff. VOCs were detected in precipitation adjacent to a highway in England, and chloromethane, toluene, xylenes, 1,2,4-trimethylbenzene, and 1,2,3-trichloropropane were detected in runoff from a highway in Texas. In urban stormwater, gasoline-related compounds were detected in as many as 23 percent of the samples. Land use could be the most significant factor affecting the occurrence of VOCs, with highest concentrations of VOCs found in industrial areas. Temperature is another factor affecting the occurrence and concentrations of VOCs. Urban land surfaces are the primary nonpoint source of VOCs in stormwater. However, the atmosphere is a potential source of hydrophilic VOCs in stormwater, especially during cold seasons when partitioning of VOCs from air into water i

Consequences of variation in stream-landscape connections for stream nitrate retention and export

NASA Astrophysics Data System (ADS)

Handler, A. M.; Helton, A. M.; Grimm, N. B.

2017-12-01

Hydrologic and material connections among streams, the surrounding terrestrial landscape, and groundwater systems fluctuate between extremes in dryland watersheds, yet the consequences of this variation for stream nutrient retention and export remain uncertain. We explored how seasonal variation in hydrologic connection among streams, landscapes, and groundwater affect nitrate and ammonium concentrations across a dryland stream network and how this variation mediates in-stream nitrate uptake and watershed export. We conducted spatial surveys of stream nitrate and ammonium concentration across the 1200 km2 Oak Creek watershed in central Arizona (USA). In addition, we conducted pulse releases of a solution containing biologically reactive sodium nitrate, with sodium chloride as a conservative hydrologic tracer, to estimate nitrate uptake rates in the mainstem (Q>1000 L/s) and two tributaries. Nitrate and ammonium concentrations generally increased from headwaters to mouth in the mainstem. Locally elevated concentrations occurred in spring-fed tributaries draining fish hatcheries and larger irrigation ditches, but did not have a substantial effect on the mainstem nitrogen load. Ambient nitrate concentration (as N) ranged from below the analytical detection limit of 0.005 mg/L to 0.43 mg/L across all uptake experiments. Uptake length—average stream distance traveled for a nutrient atom from the point of release to its uptake—at ambient concentration ranged from 250 to 704 m and increased significantly with higher discharge, both across streams and within the same stream on different experiment dates. Vertical uptake velocity and aerial uptake rate ranged from 6.6-10.6 mm min-1 and 0.03 to 1.4 mg N m-2 min-1, respectively. Preliminary analyses indicate potentially elevated nitrogen loading to the lower portion of the watershed during seasonal precipitation events, but overall, the capacity for nitrate uptake is high in the mainstem and tributaries. Ongoing work focuses on how seasonal variability in connections between the stream and sources of nitrogen affect in-stream nitrate and ammonium uptake rates and watershed export. Episodic connections between dryland streams and the surrounding landscape can have a strong effect on stream nitrogen loads, uptake, and export.

Emergence flux declines disproportionately to larval density along a stream metals gradient

USGS Publications Warehouse

Schmidt, Travis S.; Kraus, Johanna M.; Walters, David M.; Wanty, Richard B.

2013-01-01

Effects of contaminants on adult aquatic insect emergence are less well understood than effects on insect larvae. We compared responses of larval density and adult emergence along a metal contamination gradient. Nonlinear threshold responses were generally observed for larvae and emergers. Larval densities decreased significantly at low metal concentrations but precipitously at concentrations of metal mixtures above aquatic life criteria (Cumulative Criterion Accumulation Ratio (CCAR) ≥ 1). In contrast, adult emergence declined precipitously at low metal concentrations (CCAR ≤ 1), followed by a modest decline above this threshold. Adult emergence was a more sensitive indicator of the effect of low metals concentrations on aquatic insect communities compared to larvae, presumably because emergence is limited by a combination of larval survival and other factors limiting successful emergence. Thus effects of exposure to larvae are not manifest until later in life (during metamorphosis and emergence). This loss in emergence reduces prey subsidies to riparian communities at concentrations considered safe for aquatic life. Our results also challenge the widely held assumption that adult emergence is a constant proportion of larval densities in all streams.

Implications for Ecosystem Services of Watershed Processes that affect the Transport and Transformations of Mercury in an Adirondack Stream Basin

NASA Astrophysics Data System (ADS)

Burns, D. A.; Riva-Murray, K.; Bradley, P. M.

2012-12-01

Mercury (Hg) is a potent neurotoxin that can affect the health of humans and wildlife through the ingestion of methyl Hg. Mercury contamination of ecosystems originates from human activities such as mining, coal burning and other industrial emissions, and the use of Hg-containing products. Natural sources such as volcanic and geothermal emissions and the weathering of Hg-bearing minerals also contribute to Hg contamination, but are believed to be minor sources in most ecosystems. Various ecosystem disturbances including fires, forest harvesting, and the submergence of land by impoundment may also contribute to Hg ecosystem contamination by mobilizing stores that have previously originated from the sources described above. Mercury from a mix of regional and global emissions sources is transported in the atmosphere to remote landscapes that are distant from local emissions sources. The Adirondacks of New York State is a forested, mountainous region characterized by abundant lakes and streams, and is distant from local emissions sources. Recreational fishing, wildlife viewing, hiking, and hunting are valued ecosystem services in this region. Here, we report on the relevance to ecosystem services of findings based on five years of Hg data collection of stream water, groundwater, invertebrates, and fish in the upper Hudson River basin in the central part of the Adirondack region. The New York State Dept. of Health has issued fish consumption advisories for the entire Adirondacks based on elevated levels previously measured in lakes and rivers of this region. Our work seeks improved understanding and models of the landscape sources and watershed processes that control the transformation of Hg to its methyl form (MeHg), the transport of MeHg to streams, and bioaccumulation of MeHg in aquatic food webs. Mean annual atmospheric Hg deposition was 6.3 μg/m2/yr during 2007-09, compared to mean annual filtered total Hg stream yields of 1.66 μg/m2/yr and filtered MeHg stream yields of 0.095 μg/m2/yr in a sub-basin of the upper Hudson during this same period. Our work shows that Hg in stream biota, which is largely in the methyl form, is strongly related to MeHg measured in the water column; food web factors that affect Hg bioaccumulation also play a role. In brook trout, the top aquatic predator in the food web of the upper Hudson, Hg concentrations average about 0.1 μg/g, a level believed to affect fish behavior, and a few values were greater than 0.3 μg/g, a level at which human fish consumption advisories are issued. Landscape-based regression models that account for about 80% of the variation in stream MeHg concentrations at 25 sites across the upper Hudson basin include metrics of riparian area and open water indicating the importance of these landscape types in affecting methylation rates, losses of MeHg (through demethylation and other processes), and the transport of MeHg to surface waters. These and other study results indicate that factors such as watershed geomorphology, seasonal variations in discharge and air temperature, and the location and connection of riparian wetlands to streams are the strongest factors that affect stream MeHg concentrations and therefore, the potential ecosystem services provided by fish and other wildlife in the Adirondack region.

Estimating pesticide runoff in small streams.

PubMed

Schriever, Carola A; von der Ohe, Peter C; Liess, Matthias

2007-08-01

Surface runoff is one of the most important pathways for pesticides to enter surface waters. Mathematical models are employed to characterize its spatio-temporal variability within landscapes, but they must be simple owing to the limited availability and low resolution of data at this scale. This study aimed to validate a simplified spatially-explicit model that is developed for the regional scale to calculate the runoff potential (RP). The RP is a generic indicator of the magnitude of pesticide inputs into streams via runoff. The underlying runoff model considers key environmental factors affecting runoff (precipitation, topography, land use, and soil characteristics), but predicts losses of a generic substance instead of any one pesticide. We predicted and evaluated RP for 20 small streams. RP input data were extracted from governmental databases. Pesticide measurements from a triennial study were used for validation. Measured pesticide concentrations were standardized by the applied mass per catchment and the water solubility of the relevant compounds. The maximum standardized concentration per site and year (runoff loss, R(Loss)) provided a generalized measure of observed pesticide inputs into the streams. Average RP explained 75% (p<0.001) of the variance in R(Loss). Our results imply that the generic indicator can give an adequate estimate of runoff inputs into small streams, wherever data of similar resolution are available. Therefore, we suggest RP for a first quick and cost-effective location of potential runoff hot spots at the landscape level.

Variation in fish mercury concentrations in streams of the Adirondack region, New York: A simplified screening approach using chemical metrics

USGS Publications Warehouse

Burns, Douglas A.; Riva-Murray, Karen

2018-01-01

Simple screening approaches for the neurotoxicant methylmercury (MeHg) in aquatic ecosystems may be helpful in risk assessments of natural resources. We explored the development of such an approach in the Adirondack Mountains of New York, USA, a region with high levels of MeHg bioaccumulation. Thirty-six perennial streams broadly representative of 1st and 2nd order streams in the region were sampled during summer low flow and analyzed for several solutes and for Hg concentrations in fish. Several landscape and chemical metrics that are typically strongly related to MeHg concentrations in aquatic biota were explored for strength of association with fish Hg concentrations. Data analyses were based on site mean length-normalized and standardized Hg concentrations (assumed to be dominantly MeHg) in whole juvenile and adult Brook Trout Salvelinus fontinalis, Creek Chub Semotilus atromaculatus, Blacknose Dace Rhinichthys atratulus, and Central Mudminnow Umbra limi, as well as on multi-species z-scores. Surprisingly, none of the landscape metrics was related significantly to regional variation in fish Hg concentrations or to z-scores across the study streams. In contrast, several chemical metrics including dissolved organic carbon (DOC) concentrations, sulfate concentrations (SO42−), pH, ultra-violet absorbance (UV254), and specific ultra-violet absorbance were significantly related to regional variation in fish Hg concentrations. A cluster analysis based on DOC, SO42−, and pH identified three distinct groups of streams: (1) high DOC, acidic streams, (2) moderate DOC, slightly acidic streams, and (3) low DOC circum-neutral streams with relatively high SO42−. Preliminary analysis indicated no significant difference in fish Hg z-scores between the moderate and high DOC groups, so these were combined for further analysis. The resulting two groups showed strong differences (p < 0.001) in DOC and SO42−concentrations as well as in pH and UV254 values. Median fish z-scores were significantly higher (p = 0.002) in the group of streams with higher DOC and UV254 and lower pH and SO42−. Screening values of DOC >6.9 mg/L, SO42− <2.8 mg/L, pH <6.6, and UV254>0.31 cm−1 were tested as thresholds to identify Adirondack stream sites likely to have higher fish Hg concentrations. By applying a combined threshold of exceedance for either pH or UV254, sites with fish Hg concentrations that exceeded a wildlife guideline of 100 ng/g were correctly identified about 75% of the time among the 36 study streams. An estimate of Hg risk applied to a data set of 391 streams based on DOC concentrations showed that about 28% were likely to pose high risk to wildlife; most of these streams were located in the western Adirondacks.

Long-term response of surface water acid neutralizing capacity in a central Appalachian (USA) river basin to declining acid deposition

NASA Astrophysics Data System (ADS)

Kline, Kathleen M.; Eshleman, Keith N.; Garlitz, James E.; U'Ren, Sarah H.

2016-12-01

Long-term changes in acid-base chemistry resulting from declining regional acid deposition were examined using data from repeating synoptic surveys conducted within the 275 km2 Upper Savage River Watershed (USRW) in western Maryland (USA); a randomly-selected set of 40 stream reaches was sampled 36 times between 1999 and 2014 to: (1) repeatedly characterize the acid-base status of the entire river basin; (2) determine whether an extensive network of streams of varying order has shown signs of recovery in acid neutralizing capacity (ANC); and (3) understand the key factors controlling the rate of ANC recovery across the river network. Several non-parametric analyses of trends (i.e., Mann Kendall Trend: MKT tests; and Regional Kendall Trend: RKT) in streamwater acid-base chemistry suggest that USRW has significantly responded to declining acid deposition during the study period; the two most robust, statistically significant trends were decreasing surface water SO42- (∼1.5 μeq L-1 yr-1) and NO3- (∼1 μeq L-1 yr-1) concentrations-consistent with observed downward trends in regional wet S and N deposition. Basin-wide decreasing trends in K+, Mg2+, and Ca2+ were also observed, while Na+ concentrations increased. Significant ANC recovery was observed in 10-20% of USRW stream reaches (depending on the p level used), but the magnitude of the trend relative to natural variability was apparently insufficient to allow detection of a basin-wide ANC trend using the RKT test. Watershed factors, such as forest disturbances and increased application of road deicing salts, appeared to contribute to substantial variability in concentrations of NO3- and Na+ in streams across the basin, but these factors did not affect our overall interpretation of the results as a systematic recovery of USRW from regional acidification. Methodologically, RKT appears to be a robust method for identifying basin-wide trends using synoptic data, but MKT results for individual systems should be examined closely (e.g., to identify trends for specific subpopulations).

Estimation of methane concentrations and loads in groundwater discharge to Sugar Run, Lycoming County, Pennsylvania

USGS Publications Warehouse

Heilweil, Victor M.; Risser, Dennis W.; Conger, Randall W.; Grieve, Paul L.; Hynek, Scott A.

2014-01-01

A stream-sampling study was conducted to estimate methane concentrations and loads in groundwater discharge to a small stream in an active shale-gas development area of northeastern Pennsylvania. Grab samples collected from 15 streams in Bradford, Lycoming, Susquehanna, and Tioga Counties, Pa., during a reconnaissance survey in May and June 2013 contained dissolved methane concentrations ranging from less than the minimum reporting limit (1.0) to 68.5 micrograms per liter (µg/L). The stream-reach mass-balance method of estimating concentrations and loads of methane in groundwater discharge was applied to a 4-kilometer (km) reach of Sugar Run in Lycoming County, one of the four streams with methane concentrations greater than or equal to 5 µg/L. Three synoptic surveys of stream discharge and methane concentrations were conducted during base-flow periods in May, June, and November 2013. Stream discharge at the lower end of the reach was about 0.10, 0.04, and 0.02 cubic meters per second, respectively, and peak stream methane concentrations were about 20, 67, and 29 µg/L. In order to refine estimated amounts of groundwater discharge and locations where groundwater with methane discharges to the stream, the lower part of the study reach was targeted more precisely during the successive studies, with approximate spacing between stream sampling sites of 800 meters (m), 400 m, and 200 m, in May, June, and November, respectively. Samples collected from shallow piezometers and a seep near the location of the peak methane concentration measured in streamwater had groundwater methane concentrations of 2,300 to 4,600 µg/L. These field data, combined with one-dimensional stream-methane transport modeling, indicate groundwater methane loads of 1.8 ±0.8, 0.7 ±0.3, and 0.7 ±0.2 kilograms per day, respectively, discharging to Sugar Run. Estimated groundwater methane concentrations, based on the transport modeling, ranged from 100 to 3,200 µg/L. Although total methane load and the uncertainty in calculated loads both decreased with lower streamflow conditions and finer-resolution sampling in June and November, the higher loads during May could indicate seasonal variability in base flow. This is consistent with flowmeter measurements indicating that there was less inflow occurring at lower streamflow conditions during June and November.

Temporal changes in dissolved 137Cs concentrations in groundwater and stream water in Fukushima after the Fukushima Dai-ichi Nuclear Power Plant accident.

PubMed

Iwagami, Sho; Tsujimura, Maki; Onda, Yuichi; Nishino, Masataka; Konuma, Ryohei; Abe, Yutaka; Hada, Manami; Pun, Ishwar; Sakaguchi, Aya; Kondo, Hiroaki; Yamamoto, Masayoshi; Miyata, Yoshiki; Igarashi, Yasuhito

2017-01-01

The concentration of dissolved 137 Cs in groundwater and stream water in the headwater catchments in Yamakiya district, located ∼35 km north west of Fukushima Dai-ichi Nuclear Power Plant (FDNPP), was monitored from June 2011 to July 2013, after the earthquake and tsunami disaster. Groundwater and stream water were sampled at intervals of approximately 2 months at each site. Intensive sampling was also conducted during rainstorm events. Compared with previous data from the Chernobyl NPP accident, the concentration of dissolved 137 Cs in stream water was low. In the Iboishi-yama catchment, a trend was observed for the concentration of dissolved 137 Cs in stream water to decline, which could be divided into two phases by October 2011 (a fast flush of activity as a result of rapid washoff and a slow decline as a result of soil fixation and redistribution processes). The highest 137 Cs concentration recorded at Iboishi-yama was 1.2 Bq/L on August 6, 2011, which then declined to 0.021-0.049 Bq/L during 2013 (in stream water under normal water-flow conditions). During the rainfall events, the concentration of dissolved 137 Cs in stream water increased temporarily. The concentration of dissolved 137 Cs in groundwater at a depth of 30 m at Iboishi-yama displayed a decreasing trend from 2011 to 2013, with a range from 0.039 Bq/L to 0.0025 Bq/L. The effective half-lives of stream water in the initial fast flush and secondary phases were 0.10-0.21 and 0.69-1.5 y, respectively in the three catchments. The effective half-life of groundwater was 0.46-0.58 y at Koutaishi-yama and 0.50-3.3 y at Iboishi-yama. The trend for the concentration of dissolved 137 Cs to decline in groundwater and stream water was similar throughout 2012-2013, and the concentrations recorded in deeper groundwater were closer to those in stream water. The declining trend of dissolved 137 Cs concentrations in stream water was similar to that of the loss of canopy 137 Cs by throughfall, as shown in other reports of forest sites in the Yamakiya district. Copyright © 2016. Published by Elsevier Ltd.

Spatio-temporal variation in stream water chemistry in a tropical urban watershed

Treesearch

A. Ramirez; K.G. Rosas; A.E. Lugo; O.M. Ramos-Gonzalez

2014-01-01

Urban activities and related infrastructure alter the natural patterns of stream physical and chemical conditions. According to the Urban Stream Syndrome, streams draining urban landscapes are characterized by high concentrations of nutrients and ions, and might have elevated water temperatures and variable oxygen concentrations. Here, we report temporal and spatial...

Effects of land use and surficial geology on flow and water quality of streams in the coal-mining region of southwestern Indiana, October 1979 through September 1980

USGS Publications Warehouse

Wilber, William G.; Renn, Danny E.; Crawford, Charles G.

1985-01-01

The effect of surficial geology on stream quality was evident for several dissolved constituents in forested and agricultural watersheds. In general, pH and concentrations of alkalinity and calcium were significantly higher in streams draining the Wisconsin glacial province than in streams draining the Illinoian glacial province and unglaciated regions. The higher pH and concentrations of these constituents suggests that there is greater dissolution of carbonate minerals in the Wisconsin glacial province than the other regions. Median concentrations of arsenic, lead, and manganese for streams draining the Wisconsin glacial province were significantly lower than for those constituents in streams draining the Illinoian province and unglaciated region. The median cadmium concentration for streams draining the Wisconsin glacial province was lower than for streams draining the unglaciated region. These differences may have been due to lower solubilities of metal and trace elements at higher pH values in the Wisconsin glacial province than in the Illinoian glacial province and the unglaciated region.

Geochemistry and exploration criteria for epithermal cinnabar and stibnite vein deposits in the Kuskokwim River region, southwestern Alaska

USGS Publications Warehouse

Gray, J.E.; Goldfarb, R.J.; Detra, D.E.; Slaughter, K.E.

1991-01-01

Cinnabar- and stibnite-bearing epithermal vein deposits are found throughout the Kuskokwim River region of southwestern Alaska. A geochemical orientation survey was carried out around several of these epithermal lodes to obtain information for planning regional geochemical surveys and to develop procedures which maximize the anomaly: threshold contrast of the deposits. Stream sediment, heavy-mineral concentrate, stream water, and vegetation samples were collected in drainages surrounding the Red Devil, Cinnabar Creek, White Mountain, Rhyolite, and Mountain Top deposits. Three sediment size fractions; nonmagnetic, paramagnetic and magnetic splits of the concentrate samples; stream waters; and the vegetation samples were analyzed for multi-element suites by a number of different chemical procedures. Nonmagnetic, heavy-mineral concentrates were also examined microscopically to identify their mineralogy. Results confirm Hg, Sb and As concentrations in minus-80-mesh stream sediments as effective pathfinder elements in exploration for epithermal cinnabar and stibnite deposits. Coarser-grained sediments are much less effective in the exploration for these deposits. Concentrations greater than 3 ppm Hg, 1 ppm Sb, and 15 ppm As in the minus-80-mesh stream sediment, regardless of the host lithology, are indicative of upstream cinnabar-stibnite deposits. Gold, Ag and base metals in the stream sediments are ineffective pathfinders for this epithermal deposit type. Collection of heavy-mineral concentrates provides little advantage in the exploration for these mineral deposits. Antimony and As dispersion patterns downstream from mineralized areas are generally more restricted in the concentrates than those in the stream sediments. Anomalous placer cinnabar observed in the concentrates has a similar spatial distribution pattern as anomalous Hg and Sb in corresponding sediments. Stream waters are less effective than the stream sediments or heavy-mineral concentrates, and vegetation is an ineffective geochemical sample medium in exploration for this deposit type. ?? 1991.

Nutrient dynamics across a dissolved organic carbon and burn gradient in central Siberia

NASA Astrophysics Data System (ADS)

Rodriguez-Cardona, B.; Coble, A. A.; Prokishkin, A. S.; Kolosov, R.; Spencer, R. G.; Wymore, A.; McDowell, W. H.

2016-12-01

In stream ecosystems, dissolved organic carbon (DOC) and nitrogen (N) processing are tightly linked. In temperate streams, greater DOC concentrations and higher DOC:NO3- ratios promote the greatest nitrate (NO3-) uptake. However, less is known about this relationship in other biomes including the arctic which is undergoing changes due to climate change contributing to thawing of permafrost and alterations in biogeochemical cycles in soils and streams. Headwater streams draining into the N. Tunguska River in the central Siberian plateau are affected by forest fires but little is known about the aquatic biogeochemical implications in both a thawing and burning landscape. There are clear patterns between carbon concentration and fire history where generally DOC concentration in streams decrease after fires and older burn sites have shown greater DOC concentrations and more bioavailable DOC that could promote greater heterotrophic uptake of NO3-. However, the relationship between nutrient dynamics, organic matter composition, and fire history in streams is not very clear. In order to assess the influence of organic matter composition and DOC concentration on nutrient uptake in arctic streams, we conducted a series of short-term nutrient addition experiments following the tracer addition for spiraling curve characterization (TASCC) method, consisting of NO3- and NH4++PO43- additions, across 4 streams that comprise a fire gradient that spans 3- >100 years since the last burn with DOC concentrations ranging between 12-23 mg C/L. We hypothesized that nutrient uptake would be greatest in older burn sites due to greater DOC concentrations and availability. We will specifically examine how nutrient uptake relates to DOC concentration and OM composition (analyzed via FTICR-MS) across the burn gradient. Across the four sites DOC concentration and DOC:NO3- ratios decreased from old burn sites to recently burned sites. Results presented here can elucidate on the potential impacts of permafrost thawing and forest fires on nutrient dynamics in arctic streams.

"Land-Cover Conversion in Amazonia, The Role of ENV" Ironment and Substrate composition in Modifying SOI

NASA Technical Reports Server (NTRS)

Roberts, Dar A.; Chadwick, Oliver A.; Batista, Getulio T.

2003-01-01

LBA research from the first phase of LBA focused on three broad categories: 1) mapping land cover and quantifying rates of change, persistence of pasture, and area of recovering forest; 2) evaluating the role of environmental factors and land-use history on soil biogeochemistry; and 3) quantifying the natural and human controls on stream nutrient concentrations. The focus of the research was regional, concentrating primarily in the state of RondBnia, but also included land-cover mapping in the vicinity of Maraba, Para, and Manaus, Amazonas. Remote sensing analysis utilized Landsat Thematic Mapper (TM) and Multispectral Scanner (MS S) data to map historical patterns of land-cover change. Specific questions addressed by the remote sensing component of the research included: 1) what is the areal extent of dominant land-cover classes? 2) what are the rates of change of dominant land cover through processes of deforestation, disturbance and regeneration? and 3) what are the dynamic properties of each class that characterize temporal variability, duration, and frequency of repeat disturbance? Biogeochemical analysis focused on natural variability and impacts of land-use/land-cover changes on soil and stream biogeochemical properties at the regional scale. An emphasis was given to specific soil properties considered to be primary limiting factors regionally, including phosphorus, nitrogen, base cations and cation-exchange properties. Stream sampling emphasized the relative effects of the rates and timing of land-cover change on stream nutrients, demonstrating that vegetation conversion alone does not impact nutrients as much as subsequent land use and urbanization.

The effect of topography and rock type on soil cation contents and stream solute and phosphorus concentrations of streams in the southwestern Brazilian Amazon basin.

NASA Astrophysics Data System (ADS)

Biggs, T. W.; Dunne, T.; Holmes, K.; Martinelli, L. A.

2001-12-01

Topography plays an important role in determining soil properties, stream solute concentrations and landscape denudation rates. Stallard (1985) suggested that catchment denudation rates should depend on soil thickness. Areas with low slopes are limited by the rate of transport of sediment, and typically contain thick soils that prevent interaction of stream waters with underlying bedrock [Stallard 1985]. Steep areas typically have thin soils, but a lower hydrologic residence time that may prevent soil water from coming into thermodynamic equilibrium with the soil-rock complex. In a survey of streams in the Brazilian Amazon basin, Biggs et al. (2001) found that stream solute concentrations correlate with soil cation contents in the humid tropics, but the mechanism underlying the correlation has not been determined. We combine chemical analyses of water samples from ~40 different streams with soil surveys, geology maps, and a 100m resolution DEM to examine the relationship between topography, rock type, soil cation contents, and stream solute concentrations in the Brazilian Amazon state of Rondônia. The basins are all more than 60% forested at the time of stream sampling and lie on granite-gneiss rocks, tertiary sediments, or sandstone. The catchment-averaged slope correlates positively with both soil cation contents and stream concentrations of P, Na, Ca, Mg, K, Si, ANC, and pH. Though we have no data about the relationship between soil depth and average slope, we assume an inverse correlation, so the data demonstrates that thick soils yield lower solute concentrations. Stream concentrations of Ca, Mg, ANC and pH reach a maximum at intermediate average slopes (3 degrees), suggesting that denudation rates may increase with slope up to a maximum, when the catchment becomes limited by the weathering rate of the basement rock. Catchments on mica-schists or mafic rocks have low average slopes and higher concentrations of Ca, Mg, Si, ANC, and pH than catchments on granite-gneiss, tertiary sediments or sandstone.

Thinking beyond the Bioreactor Box: Incorporating Stream Ecology into Edge-of-Field Nitrate Management.

PubMed

Goeller, Brandon C; Febria, Catherine M; Harding, Jon S; McIntosh, Angus R

2016-05-01

Around the world, artificially drained agricultural lands are significant sources of reactive nitrogen to stream ecosystems, creating substantial stream health problems. One management strategy is the deployment of denitrification enhancement tools. Here, we evaluate the factors affecting the potential of denitrifying bioreactors to improve stream health and ecosystem services. The performance of bioreactors and the structure and functioning of stream biotic communities are linked by environmental parameters like dissolved oxygen and nitrate-nitrogen concentrations, dissolved organic carbon availability, flow and temperature regimes, and fine sediment accumulations. However, evidence of bioreactors' ability to improve waterway health and ecosystem services is lacking. To improve the potential of bioreactors to enhance desirable stream ecosystem functioning, future assessments of field-scale bioreactors should evaluate the influences of bioreactor performance on ecological indicators such as primary production, organic matter processing, stream metabolism, and invertebrate and fish assemblage structure and function. These stream health impact assessments should be conducted at ecologically relevant spatial and temporal scales. Bioreactors have great potential to make significant contributions to improving water quality, stream health, and ecosystem services if they are tailored to site-specific conditions and implemented strategically with land-based and stream-based mitigation tools within watersheds. This will involve combining economic, logistical, and ecological information in their implementation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Episodic acidification of small streams in the northeastern united states: ionic controls of episodes

USGS Publications Warehouse

Wigington, P.J.; DeWalle, David R.; Murdoch, Peter S.; Kretser, W.A.; Simonin, H.A.; Van Sickle, J.; Baker, J.P.

1996-01-01

As part of the Episodic Response Project (ERP), we intensively monitored discharge and stream chemistry of 13 streams located in the Northern Appalachian region of Pennsylvania and in the Catskill and Adirondack Mountains of New York from fall 1988 to spring 1990. The ERP clearly documented the occurrence of acidic episodes with minimum episodic pH ??? 5 and inorganic monomeric Al (Alim) concentrations >150 ??g/L in at least two study streams in each region. Several streams consistently experienced episodes with maximum Alim concentrations >350 ??g/L. Acid neutralizing capacity (ANC) depressions resulted from complex interactions of multiple ions. Base cation decreases often made the most important contributions to ANC depressions during episodes. Organic acid pulses were also important contributors to ANC depressions in the Adirondack streams, and to a lesser extent, in the Catskill and Pennsylvania streams. Nitrate concentrations were low in the Pennsylvania streams, whereas the Catskill and Adirondack study streams had high NO3- concentrations and large episodic pulses (???54 ??eq/L). Most of the Pennsylvania study streams also frequently experienced episodic pulses of SO42- (???78 ??eq/L), whereas the Adirondack and Catskill streams did not. High baseline concentrations of SO42- (all three study areas) and NO3- (Adirondacks and Catskills) reduced episodic minimum ANC, even when these ions did not change during episodes. The ion changes that controlled the most severe episodes (lowest minimum episodic ANC) differed from the ion changes most important to smaller, more frequent episodes. Pulses of NO3- (Catskills and Adirondacks), SO42- (Pennsylvania), or organic acids became more important during major episodes. Overall, the behavior of streamwater SO42- and NO4- is an indicator that acidic deposition has contributed to the severity of episodes in the study streams.

Soil plutonium and cesium in stream channels and banks of Los Alamos liquid effluent-receiving areas.

PubMed

Nyhan, J W; White, G C; Trujillo, G

1982-10-01

Stream channel sediments and adjacent bank soils found in three intermittent streams used for treated liquid effluent disposal at Los Alamos, New Mexico were sampled to determine the distribution of 238Pu, 239,240Pu and 137Cs. Radionuclide concentrations and inventories were determined as functions of distance downstream from the waste outfall and from the center of the stream channel, soil sampling depth, stream channel-bank physiography, and the waste use history of each disposal area. Radionuclide concentrations in channel sediments were inversely related to distances up to 10 km downstream from the outfalls. For sites receiving appreciable waste effluent additions, contaminant concentrations in bank soils decreased with perpendicular distances greater than 0.38 m from the stream channel, and with stream bank sampling depths greater than 20-40 cm. Concentrations and total inventories of radionuclides in stream bank soils generally decreased as stream bank height increased. Inventory estimates of radionuclides in channel sediments exhibited coefficients of variation that ranged 0.41-2.6, reflecting the large variation in radionuclide concentrations at each site. Several interesting temporal relationships of these radionuclides in intermittent streams were gleaned from the varying waste use histories of the three effluent-receiving areas. Eleven yr after liquid wastes were added to one canyon, the major radionuclide inventories were found in the stream bank soils, unlike most of the other currently-used receiving areas. A period of time greater than 6 yr seems to be required before the plutonium in liquid wastes currently added to the canyon is approximately equilibrated with the plutonium in the bank soils. These observations are discussed relative to waste management practices in these southwestern intermittent streams.

Estimating discharge and non-point source nitrate loading to streams from three end-member pathways using high-frequency water quality and streamflow data

NASA Astrophysics Data System (ADS)

Miller, M. P.; Tesoriero, A. J.; Hood, K.; Terziotti, S.; Wolock, D.

2017-12-01

The myriad hydrologic and biogeochemical processes taking place in watersheds occurring across space and time are integrated and reflected in the quantity and quality of water in streams and rivers. Collection of high-frequency water quality data with sensors in surface waters provides new opportunities to disentangle these processes and quantify sources and transport of water and solutes in the coupled groundwater-surface water system. A new approach for separating the streamflow hydrograph into three components was developed and coupled with high-frequency specific conductance and nitrate data to estimate time-variable watershed-scale nitrate loading from three end-member pathways - dilute quickflow, concentrated quickflow, and slowflow groundwater - to two streams in central Wisconsin. Time-variable nitrate loads from the three pathways were estimated for periods of up to two years in a groundwater-dominated and a quickflow-dominated stream, using only streamflow and in-stream water quality data. The dilute and concentrated quickflow end-members were distinguished using high-frequency specific conductance data. Results indicate that dilute quickflow contributed less than 5% of the nitrate load at both sites, whereas 89±5% of the nitrate load at the groundwater-dominated stream was from slowflow groundwater, and 84±13% of the nitrate load at the quickflow-dominated stream was from concentrated quickflow. Concentrated quickflow nitrate concentrations varied seasonally at both sites, with peak concentrations in the winter that were 2-3 times greater than minimum concentrations during the growing season. Application of this approach provides an opportunity to assess stream vulnerability to non-point source nitrate loading and expected stream responses to current or changing conditions and practices in watersheds.

HYDROGIOLOGIC FRAMEWORK, GROUND-WATER GEOCHEMISTRY, AND ASSESSMENT OF NITROGEN YIELD FROM BASE FLOW IN TWO AGRICULTURAL WATERSHEDS, KENT COUNTY, MARYLAND

EPA Science Inventory

Hydrostratigraphic and geochemical data collected in two adjacent watersheds on the Delmarva Peninsula, in Kent County, Maryland, indicate that shallow subsurface stratigraphy is an important factor that affects the concentrations of nitrogen in ground water discharging as stream...

40 CFR 60.456 - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 60.456 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... § 60.453. (2) Method 25 for the measurement of the VOC concentration in the gas stream vent. (3) Method... sampling times or smaller volumes, when necessitated by process variables or other factors, may be approved...

W-007H B Plant Process Condensate Treatment Facility. Revision 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rippy, G.L.

1995-01-20

B Plant Process Condensate (BCP) liquid effluent stream is the condensed vapors originating from the operation of the B Plant low-level liquid waste concentration system. In the past, the BCP stream was discharged into the soil column under a compliance plan which expired January 1, 1987. Currently, the BCP stream is inactive, awaiting restart of the E-23-3 Concentrator. B Plant Steam Condensate (BCS) liquid effluent stream is the spent steam condensate used to supply heat to the E-23-3 Concentrator. The tube bundles in the E-23-3 Concentrator discharge to the BCS. In the past, the BCS stream was discharged into themore » soil column. Currently, the BCS stream is inactive. This project shall provide liquid effluent systems (BCP/BCS/BCE) capable of operating for a minimum of 20 years, which does not include the anticipated decontamination and decommissioning (D and D) period.« less

Similarities and differences in occurrence and temporal fluctuations in glyphosate and atrazine in small Midwestern streams (USA) during the 2013 growing season

USGS Publications Warehouse

Mahler, Barbara J.; Van Metre, Peter C.; Burley, Thomas E.; Loftin, Keith A.; Meyer, Michael T.; Nowell, Lisa H.

2017-01-01

Glyphosate and atrazine are the most intensively used herbicides in the United States. Although there is abundant spatial and temporal information on atrazine occurrence at regional scales, there are far fewer data for glyphosate, and studies that compare the two herbicides are rare. We investigated temporal patterns in glyphosate and atrazine concentrations measured weekly during the 2013 growing season in 100 small streams in the Midwestern United States. Glyphosate was detected in 44% of samples (method reporting level 0.2 μg/L); atrazine was detected above a threshold of 0.2 μg/L in 54% of samples. Glyphosate was detected more frequently in 12 urban streams than in 88 agricultural streams, and at concentrations similar to those in streams with high agricultural land use (> 40% row crop) in the watershed. In contrast, atrazine was detected more frequently and at higher concentrations in agricultural streams than in urban streams. The maximum concentration of glyphosate measured at most urban sites exceeded the maximum atrazine concentration, whereas at agricultural sites the reverse was true. Measurement at a 2-day interval at 8 sites in northern Missouri revealed that transport of both herbicide compounds appeared to be controlled by spring flush, that peak concentration duration was brief, but that peaks in atrazine concentrations were of longer duration than those of glyphosate. The 2-day sampling also indicated that weekly sampling is unlikely to capture peak concentrations of glyphosate and atrazine.

Relations between retired agricultural land, water quality, and aquatic-community health, Minnesota River Basin

USGS Publications Warehouse

Christensen, Victoria G.; Lee, Kathy E.; McLees, James M.; Niemela, Scott L.

2012-01-01

The relative importance of agricultural land retirement on water quality and aquatic-community health was investigated in the Minnesota River Basin. Eighty-two sites, with drainage areas ranging from 4.3 to 2200 km2, were examined for nutrient concentrations, measures of aquatic-community health (e.g., fish index of biotic integrity [IBI] scores), and environmental factors (e.g., drainage area and amount of agricultural land retirement). The relation of proximity of agricultural land retirement to the stream was determined by calculating the land retirement percent in various riparian zones. Spearman's rho results indicated that IBI score was not correlated to the percentage of agricultural land retirement at the basin scale (p = 0.070); however, IBI score was correlated to retired land percentage in the 50- to 400-m riparian zones surrounding the streams (p < 0.05), indicating that riparian agricultural land retirement may have more influence on aquatic-community health than does agricultural land retirement in upland areas. Multivariate analysis of covariance and analysis of covariance models indicated that other environmental factors (such as drainage area and lacustrine and palustrine features) commonly were correlated to aquatic-community health measures, as were in-stream factors (standard deviation of water depth and substrate type). These results indicate that although agricultural land retirement is significantly related to fish communities as measured by the IBI scores, a combination of basin, riparian, and in-stream factors act together to influence IBI scores.

New studies initiated by the U.S. Geological Survey - Effects of nutrient enrichment on stream ecosystems

USGS Publications Warehouse

Munn, Mark D.; Hamilton, Pixie A.

2003-01-01

In 2001, the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program began an intensive study of nutrient enrichment elevated concentrations of nitrogen and phosphorus in streams in five agricultural basins across the Nation (see map, p. 2). This study is providing nationally consistent and comparable data and analyses of nutrient conditions, including how these conditions vary as a result of natural and human-related factors, and how nutrient conditions affect algae and other biological communities. This information will benefit stakeholders, including the U.S. Environmental Protection Agency (USEPA) and its partners, who are developing nutrient criteria to protect the aquatic health of streams in different geographic regions.Nutrient enrichment is one of five national priority topics addressed by NAWQA in its second decade of studies, which began in 2001. During its first round of assessments in 51 major river basins (referred to as “Study Units”), NAWQA scientists collected data on water chemistry, stream hydrology and habitat, and biological communities; currently, NAWQA is revisiting selected basins and focusing on (1) trends, (2) factors that affect water quality and aquatic health, and (3) national priority water issues related to, for example, the development of nutrient criteria, source-water protection strategies, and stream restoration plans.The nutrient enrichment study has four major objectives that address nutrient conditions, dissolved oxygen, aquatic communities, and geographic and landscape features in agricultural basins (see inset). The focus on agricultural streams is a starting point. As the study progresses, streams draining other land uses, such as those in residential and urban areas, will likely be added.

Continuous aqueous tritium monitor

DOEpatents

McManus, Gary J.; Weesner, Forrest J.

1989-05-30

An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture and selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration.

Control of gas contaminants in air streams through biofiltration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holt, T.; Lackey, L.

1996-11-01

According to the National Institute for Occupational Safety and Health (NIOSH), the maximum styrene concentration allowed in the work place is 50 ppm for up to a 10-hour work day during a 40-hour work week. The US EPA has classified styrene as one of the 189 hazardous air pollutants listed under Title 3 of the Clean Air Act Amendments to be reduced by a factor of 90% by the year 2000. Significant quantities of styrene are emitted to the atmosphere each year by boat manufacturers. A typical fiberglass boat manufacturing facility can emit over 273 metric tons/year of styrene. Themore » concentration of styrene in the industrial exhaust gas ranges from 20 to 100 ppmv. Such dilute, high volume organically tainted air streams can make conventional abatement technologies such as thermal incineration, adsorption, or absorption technically incompetent or prohibitively expensive. An efficient, innovative, and economical means of remediating styrene vapors would be of value to industries and to the environment. Biofilter technology depends on microorganisms that are immobilized on the packing material in a solid phase reactor to remove or degrade environmentally undesirable compounds contaminating gas streams. The technology is especially successful for treating large volumes of air containing low concentrations of contaminants. The objective of this study was to investigate the feasibility of using biofiltration to treat waste gas streams containing styrene and to determine the critical design and operating parameters for such a system.« less

Ecotoxicological impact of highway runoff using brown trout (Salmo trutta L.) as an indicator model.

PubMed

Meland, Sondre; Salbu, Brit; Rosseland, Bjørn Olav

2010-03-01

The ecotoxicological impact of highway runoff on brown trout (Salmo trutta L.) was studied in an in situ experiment consisting of four 24 h simulated runoff episodes. Fish were maintained in 5 tanks and exposed to highway runoff from a sedimentation pond close to E6 outside the city of Oslo, Norway. The tanks had the following contaminant loadings during the episodes: stream water (control), pond inlet, pond outlet, pond inlet + stream water and pond outlet + stream water. Opposite to road salt and compared to earlier findings, the first two episodes had rather low concentrations of trace metals, hydrocarbons and polycyclic aromatic hydrocarbons. A heavy rainfall before episode 3 increased the concentrations of all the contaminants except road salt which was diluted. In addition, lowered oxygen levels led to hypoxic conditions. Overall the fish exposed to highway runoff had, compared to the control fish, higher concentrations of trace metals in gills and liver, increased activity of the antioxidant defense system represented by superoxide dismutase, catalase and metallothionein, problems with the regulation of plasma Cl and Na, as well as increased levels of blood glucose and pCO(2). Finally, this seemed to affect the metabolism of the fish through reduced condition factor. The observed effects were likely caused by multiple stressors and not by a single contaminant. The sedimentation pond clearly reduced the toxicity of the highway runoff. But even in the least polluted exposure tank (pond outlet + stream water) signs of physiological disturbances were evident.

Organic carbon and nitrogen concentrations and annual organic carbon load of six selected rivers of the United States

USGS Publications Warehouse

Malcolm, R.L.; Durum, W.H.

1976-01-01

The organic carbon load during 1969-70 of each of the six rivers in this study is substantial. The 3.4-billion-kilogram (3.7-million-ton) and 47-million-kilogram (52-thousandton) annual organic carbon loads of the Mississippi River and the Brazos River (Tex.), respectively, were approximately equally distributed between dissolved and suspended phases, whereas the 725-million-kilogram (79.8-million-ton) organic load of the Missouri River was primarily in the suspended phase. The major portion of the 6.4-million-kilogram (7.3 thousand-ton) and the 19-million-kilogram (21-thousand-ton) organic carbon loads of the Sopchoppy River (Fla.) and the Neuse River (N.C.), respectively, was in the dissolved phase. DOC (dissolved organic carbon) concentrations in most rivers were usually less than 8 milligrams per litre. SOC (suspended organic carbon) concentrations fluctuated markedly with discharge, ranging between 1 and 14 percent, by weight, in sediment of most rivers. DOC concentrations were found to be independent of discharge, whereas SOC and SIC (suspended inorganic carbon) concentrations were positively correlated with discharge. Seasonal fluctuations in DOC and SOC were exhibited by the Missouri, Neuse, Ohio, and Brazos Rivers, but both SOC and DOC concentrations were relatively constant throughout the year in the Mississippi and Sopchoppy Rivers. The carbon-nitrogen ratio in the sediment phase of all river waters averaged less than 8 1 as compared with 12:1 or greater for most soils. This high nitrogen content shows a nitrogen enrichment of the stream sediment over that in adjacent soils, which suggests that different decomposition and humification processes are operating in streams than in the soils. The abundance of organic material in the dissolved and suspended phase of all river waters in this study indicate a large capacity factor for various types of organic reactivity within all streams and the quantitative importance of organic constituents in relation to the water quality of rivers and streams.

Anthropogenic Mercury Accumulation in Watersheds of the Northern Appalachian Mountains

NASA Astrophysics Data System (ADS)

Boyer, E. W.; Drohan, P. J.; Lawler, D.; Grimm, J.; Grant, C.; Eklof, K. J.; Bennett, J.; Naber, M. D.

2014-12-01

Atmospheric deposition of mercury (Hg) is a critical environmental stress that affects ecosystems and human health. Mercury emissions to the atmosphere from coal-fired power plants and other sources such as waste incineration can be deposited over large geographic areas to downwind landscapes in precipitation and in dry fallout. The northern Appalachian Mountains are downwind of major atmospheric mercury emissions sources. Some mercury reaches watersheds and streams, where it can accumulate in sediments and biota. Human exposure to mercury occurs primarily through fish consumption, and currently mercury fish eating advisories are in place for many of the streams and lakes in the region. Here, we explored mercury accumulation in forested landscapes - in air, soils, water, and biota. To quantify atmospheric mercury deposition, we measured both wet and dry mercury deposition at 10 forested locations, from which we present variation in mercury deposition and initial assessments of factors affecting the patterns. To quantify mercury accumulation in terrestrial environments, we measured soil mercury concentrations within and surrounding 12 vernal pools spanning various physiographic settings in the region. Given that vernal pools have large inputs of water via precipitation yet do not have any stream discharge outflow, they are likely spots within the forested landscape to accumulate pollutants that enter via wet atmospheric deposition. To quantify mercury accumulation in aquatic environments, we sampled mercury concentrations in streams draining 35 forested watersheds, spanning gradients of atmospheric deposition, climate and geology. Mercury concentrations were measured in stream water under base-flow conditions, in streambed sediments, aquatic mosses, and in fish tissues from brook trout. Results indicate that wet and dry atmospheric deposition is a primary source of mercury that is accumulating in watersheds of the Northern Appalachian Mountains.

Dynamic behaviour of river colloidal and dissolved organic matter through cross-flow ultrafiltration system.

PubMed

Wilding, Andrew; Liu, Ruixia; Zhou, John L

2005-07-01

Through cross-flow filtration (CFF) with a 1-kDa regenerated cellulose Pellicon 2 module, the ultrafiltration characteristics of river organic matter from Longford Stream, UK, were investigated. The concentration of organic carbon (OC) in the retentate in the Longford Stream samples increased substantially with the concentration factor (cf), reaching approximately 40 mg/L at cf 15. The results of dissolved organic carbon (DOC) and colloidal organic carbon (COC) analysis, tracking the isolation of colloids from river waters, show that 2 mg/L of COC was present in those samples and good OC mass balance (77-101%) was achieved. Fluorescence measurements were carried out for the investigation of retentate and permeate behaviour of coloured dissolved organic materials (CDOM). The concentrations of CDOM in both the retentate and permeate increased with increasing cf, although CDOM were significantly more concentrated in the retentate. The permeation model expressing the correlation between log[CDOM] in the permeate and logcf was able to describe the permeation behaviour of CDOM in the river water with regression coefficients (r(2)) of 0.94 and 0.98. Dry weight analysis indicated that the levels of organic colloidal particles were from 49 to 71%, and between 29 and 51% of colloidal particles present were inorganic. COC as a percentage of DOC was found to be 10-16% for Longford Stream samples.

Assessment of Energetic Compounds, Semi-volatile Organic Compounds, and Trace Elements in Streambed Sediment and Stream Water from Streams Draining Munitions Firing Points and Impact Areas, Fort Riley, Kansas, 2007-08

USGS Publications Warehouse

Coiner, R.L.; Pope, L.M.; Mehl, H.E.

2010-01-01

An assessment of energetic compounds (explosive and propellant residues) and associated semi-volatile organic compounds (SVOCs) and trace elements in streambed sediment and stream water from streams draining munitions firing points and impact areas at Fort Riley, northeast Kansas, was performed during 2007-08 by the U.S. Geological Survey (USGS) in cooperation with the U.S. Army. Streambed sediment from 16 sampling sites and stream-water samples from 5 sites were collected at or near Fort Riley and analyzed for as many as 17 energetic compounds, 65 SVOCs, and 27 trace elements. None of the energetic compounds or SVOCs were detected in streambed sediment collected from sites within the Fort Riley Military Reservation. This may indicate that these compounds either are not transported from dispersal areas or that analytical methods are not sensitive enough to detect the small concentrations that may be transported. Concentrations of munitions-associated trace elements did not exceed sediment-quality guidelines recommended by the U.S. Environmental Protection Agency (USEPA) and are not indicative of contamination of streambed sediment at selected streambed sampling sites, at least in regards to movement from dispersal areas. Analytical results of stream-water samples provided little evidence of contamination by energetic compounds, SVOCs, or associated trace elements. Perchlorate was detected in 19 of 20 stream-water samples at concentrations ranging from an estimated 0.057 to an estimated 0.236 ug/L (micrograms per liter) with a median concentration of an estimated 0.114 ug/L, substantially less than the USEPA Interim Health Advisory criterion (15 ug/L), and is in the range of documented background concentrations. Because of these small concentrations and possible natural sources (precipitation and groundwater), it is likely that the occurrence of perchlorate in stream water is naturally occurring, although a definitive identification of the source of perchlorate in stream water at Fort Riley is difficult. The only SVOCs detected in stream-water samples were bis(2-ethylhexyl) phthalate and di-n-butyl phthalate but at concentrations substantially less than the most stringent aquatic-life criteria established by the Kansas Department of Health and Environment. All trace element concentrations in stream-water samples were less than the most stringent aquatic-life criteria. The implication of these stream-water results is that contamination arising from firing-range activities, if it exists, is so small as to be nondetectable with current analytical methods or is not distinguishable from background concentrations for constituents that also are naturally occurring. Overall, the munitions-related constituents analyzed in streambed sediment and stream water, when detected, were at concentrations that were less than regulatory criteria

Relationships between stream nitrate concentration and spatially distributed snowmelt in high-elevation catchments of the western U.S.

NASA Astrophysics Data System (ADS)

Perrot, Danielle; Molotch, Noah P.; Williams, Mark W.; Jepsen, Steven M.; Sickman, James O.

2014-11-01

This study compares stream nitrate (NO3-) concentrations to spatially distributed snowmelt in two alpine catchments, the Green Lakes Valley, Colorado (GLV4) and Tokopah Basin, California (TOK). A snow water equivalent reconstruction model and Landsat 5 and 7 snow cover data were used to estimate daily snowmelt at 30 m spatial resolution in order to derive indices of new snowmelt areas (NSAs). Estimates of NSA were then used to explain the NO3- flushing behavior for each basin over a 12 year period (1996-2007). To identify the optimal method for defining NSAs and elucidate mechanisms underlying catchment NO3- flushing, we conducted a series of regression analyses using multiple thresholds of snowmelt based on temporal and volumetric metrics. NSA indices defined by volume of snowmelt (e.g., snowmelt ≤ 30 cm) rather than snowmelt duration (e.g., snowmelt ≤ 9 days) were the best predictors of stream NO3- concentrations. The NSA indices were better correlated with stream NO3- concentration in TOK (average R2= 0.68) versus GLV4 (average R2= 0.44). Positive relationships between NSA and stream NO3- concentration were observed in TOK with peak stream NO3- concentration occurring on the rising limb of snowmelt. Positive and negative relationships between NSA and stream NO3- concentration were found in GLV4 with peak stream NO3- concentration occurring as NSA expands. Consistent with previous works, the contrasting NO3- flushing behavior suggests that streamflow in TOK was primarily influenced by overland flow and shallow subsurface flow, whereas GLV4 appeared to be more strongly influenced by deeper subsurface flow paths.

Composition of fish communities in relation to stream acidification and habitat in the Neversink River, New York

USGS Publications Warehouse

Baldigo, Barry P.; Lawrence, G.B.

2000-01-01

The effects of acidification in lotic systems are not well documented. Spatial and temporal variability of habitat and water quality complicate the evaluation of acidification effects in streams and river. The Neversink River in the Catskill Mountains of southeastern New York, the tributaries of which vary from well buffered to severely acidified, provided an opportunity to investigate the external and magnitude of acidification effects on fish communities of headwater systems. Composition of fish communities, water quality, stream hydrology, stream habitat, and physiographic factors were characterized from 1991 to 1995 at 16 first- to fourth-order sites in the basin. Correlation and regression analyses were used to develop empirical models and to assess the relations among fish species richness, total fish density, and total biomass and environmental variables. Chronic and episodic acidification and elevated concentrations of inorganic monomeric aluminum were common, and fish populations were rare or absent from several sites in the upper reaches of the basin; as many as six fish species were collected from sites in the lower reaches of the basin. Species distribution and species richness were most highly related to stream pH, acid-neutralizing capacity (ANC), inorganic monomeric aluminum (Al(im)), calcium (Ca)2+, and potassium (K)+ concentrations, site elevation, watershed drainage area, and water temperature. Fish density was most highly related to stream pH, Al(im), ANC, K+, Ca2+, and magnesium (Mg)2+ concentrations. Fish biomass, unlike species richness and fish density, was most highly related to physical habitat characteristics, water temperature, and concentrations of Mg2+ and silicon. Acidity characteristics were of secondary importance to fish biomass at all but the most severely acidified sites. Our results indicate that (1) the total biomass of fish communities was not seriously affected at moderately to strongly acidified sites; (2) species richness and total density of fish were adversely affected at strongly to severely acidified sites; and (3) possible changes in competitive interactions may mitigate negative effects of acidification on fish communities in parts of the Neversink River Basin.

Chemical and ecological effects of contaminated tunnel wash water runoff to a small Norwegian stream.

PubMed

Meland, Sondre; Borgstrøm, Reidar; Heier, Lene Sørlie; Rosseland, Bjørn Olav; Lindholm, Oddvar; Salbu, Brit

2010-09-01

Cleaning and washing of road tunnels are routinely performed and large volumes of contaminated wash water are often discharged into nearby recipients. In the present study, traffic related contaminants were quantified in tunnel wash water (the Nordby tunnel, Norway) discharged from a sedimentation pond to a nearby small stream, Arungselva. In situ size and charge fractionation techniques were applied to quantify traffic related metal species, while PAHs were quantified in total samples. All metals and several PAHs appeared at elevated concentrations in the discharged wash water compared with concentrations measured in Arungselva upstream the pond outlet, and to concentrations measured in the pond outlet before the tunnel wash event. In addition, several contaminants (e.g. Cu, Pb, Zn, fluoranthene, pyrene) exceeded their corresponding EQS. PAH and metals like Al, Cd, Cr, Cu, Fe and Pb were associated with particles and colloids, while As, Ca, K, Mg, Mo, Ni, Sb and Zn were more associated with low molecular mass species (<10kDa). Calculated enrichment factors revealed that many of the metals were derived from anthropogenic sources, originating most likely from wear of tires (Zn), brakes (Cu and Sb), and from road salt (Na and Cl). The enrichment factors for Al, Ba, Ca, Cr, Fe, K, Mg and Ni were low, suggesting a crustal origin, e.g. asphalt wear. Based on calculated PAH ratios, PAH seemed to originate from a mixture of sources such as wear from tires, asphalt and combustion. Finally, historical fish length measurement data indicates that the fish population in the receiving stream Arungselva may have been adversely influenced by the chemical perturbations in runoffs originating from the nearby roads and tunnels during the years, as the growth in summer old sea trout (Salmo trutta L.) in downstream sections of the stream is significantly reduced compared to the upstream sections. Copyright 2010 Elsevier B.V. All rights reserved.

Optimizing stream water mercury sampling for calculation of fish bioaccumulation factors

USGS Publications Warehouse

Riva-Murray, Karen; Bradley, Paul M.; Journey, Celeste A.; Brigham, Mark E.; Scudder Eikenberry, Barbara C.; Knightes, Christopher; Button, Daniel T.

2013-01-01

Mercury (Hg) bioaccumulation factors (BAFs) for game fishes are widely employed for monitoring, assessment, and regulatory purposes. Mercury BAFs are calculated as the fish Hg concentration (Hgfish) divided by the water Hg concentration (Hgwater) and, consequently, are sensitive to sampling and analysis artifacts for fish and water. We evaluated the influence of water sample timing, filtration, and mercury species on the modeled relation between game fish and water mercury concentrations across 11 streams and rivers in five states in order to identify optimum Hgwater sampling approaches. Each model included fish trophic position, to account for a wide range of species collected among sites, and flow-weighted Hgwater estimates. Models were evaluated for parsimony, using Akaike’s Information Criterion. Better models included filtered water methylmercury (FMeHg) or unfiltered water methylmercury (UMeHg), whereas filtered total mercury did not meet parsimony requirements. Models including mean annual FMeHg were superior to those with mean FMeHg calculated over shorter time periods throughout the year. FMeHg models including metrics of high concentrations (80th percentile and above) observed during the year performed better, in general. These higher concentrations occurred most often during the growing season at all sites. Streamflow was significantly related to the probability of achieving higher concentrations during the growing season at six sites, but the direction of influence varied among sites. These findings indicate that streamwater Hg collection can be optimized by evaluating site-specific FMeHg - UMeHg relations, intra-annual temporal variation in their concentrations, and streamflow-Hg dynamics.

The role of DOM in nitrogen processing in streams across arctic regions affected by fire

NASA Astrophysics Data System (ADS)

Rodriguez-Cardona, B.; Schade, J. D.; Holmes, R. M.; Natali, S.; Mann, P. J.; Wymore, A.; Coble, A. A.; Prokishkin, A. S.; Zito, P.; Podgorski, D. C.; Spencer, R. G.; McDowell, W. H.

2017-12-01

In stream ecosystems, inputs of dissolved organic carbon (DOC) have a strong influence on nitrogen (N) processing. Previous studies have demonstrated that increases in DOC concentrations can promote greater N removal in many stream ecosystems. Most of what we know about C and N coupling comes from studies of temperate streams; less is known about this relationship in the Arctic. Streams in Arctic ecosystems are facing rapid changes in climate and disturbance regimes, in particular increasing fire frequencies that are likely to alter biogeochemical cycles. Although fires can lead to increases in NO3 concentrations in streams, the effects of fire on DOC (concentration and composition) have been difficult to generalize. We studied the relationships between DOC and N in two locations; the Central Siberian Plateau, Russia and the Yukon-Kuskokwim (YK) River Delta, Alaska. Streams in both regions show increases in NO3 concentrations after fire, while DOC concentrations decrease in Siberia but increase in streams within the YK-Delta. These patterns in DOC and NO3 create a gradient in DOC and nutrient concentrations, allowing us to study this coupling in a wider Pan-Arctic scope. In order to assess the role of DOC in Arctic N processing, we conducted NO3 and NH4 additions to stream microcosms at the Alaskan site as well as whole-stream additions in Siberia. We hypothesized that nutrient uptake would be high in older burn sites of Siberia and recently burned sites in the YK-Delta, due to greater DOC concentrations and availability. Our results suggest that nitrogen dynamics in the Alaskan sites is strongly responsive to C availability, but is less so in Siberian sites. The potential impacts of permafrost thawing and fires on DOM and nutrient dynamics thus appear to not be consistent across the Arctic suggesting that different regions of the Arctic have unique biogeochemical controls.

Changes in stream chemistry and nutrient export following a partial harvest in the Catskill Mountains, New York, USA

USGS Publications Warehouse

Wang, X.; Burns, Douglas A.; Yanai, R.D.; Briggs, R.D.; Germain, R.H.

2006-01-01

Clearcut forest harvesting typically results in large changes in stream water chemistry in northeastern North America. The effects of partial forest harvests on stream chemistry have not received as much attention, even though partial cutting is a more common forestry practice than clearcutting in this region. Changes in stream water chemistry following a partial cut are reported here from a 10 ha study catchment in a northern hardwood forest in the Catskill Mountains of southern New York, and are compared to those of a nearby 48 ha reference catchment. The lower two thirds of the treatment catchment was harvested in February-April 2002 by a shelterwood method, such that 33% of the basal area of the catchment was removed. Stream NO3-, NH4+, Ca2+, K+, and total dissolved aluminum (Alto) concentrations increased significantly after the harvest. Stream Ca2+, Mg2+ and NH4+ concentrations peaked 5 months after the initiation of the harvest, NO 3- and K+ concentrations peaked 6 months after cutting, and Alto concentrations peaked 1 year after cutting. Streamflow was not significantly affected by the harvest when compared to the flow of three nearby streams. Export of NO3- in stream water increased five-fold the year after the cut, and briefly exceeded atmospheric inputs of inorganic nitrogen during 4 months in the fall of 2002. Changes in stream NO3- and K+ concentrations were less than predicted by the relative basal area removed compared with those of a recent nearby clearcut. In contrast, changes in Ca2+, Mg 2+ and Alto concentrations were approximately proportional to basal area removal in these two cuts. Stream chemistry returned to values close to those of the pre-cut period and to reference values by early spring of 2003, just over a year after the initiation of the harvest, except for NO 3- concentrations, which remained elevated above background 18-20 months after completion of the cut.

Method for processing aqueous wastes

DOEpatents

Pickett, John B.; Martin, Hollis L.; Langton, Christine A.; Harley, Willie W.

1993-01-01

A method for treating waste water such as that from an industrial processing facility comprising the separation of the waste water into a dilute waste stream and a concentrated waste stream. The concentrated waste stream is treated chemically to enhance precipitation and then allowed to separate into a sludge and a supernate. The supernate is skimmed or filtered from the sludge and blended with the dilute waste stream to form a second dilute waste stream. The sludge remaining is mixed with cementitious material, rinsed to dissolve soluble components, then pressed to remove excess water and dissolved solids before being allowed to cure. The dilute waste stream is also chemically treated to decompose carbonate complexes and metal ions and then mixed with cationic polymer to cause the precipitated solids to flocculate. Filtration of the flocculant removes sufficient solids to allow the waste water to be discharged to the surface of a stream. The filtered material is added to the sludge of the concentrated waste stream. The method is also applicable to the treatment and removal of soluble uranium from aqueous streams, such that the treated stream may be used as a potable water supply.

Nitrate in groundwater and water sources used by riparian trees in an agricultural watershed: A chemical and isotopic investigation in southern Minnesota

USGS Publications Warehouse

Komor, Stephen C.; Magner, Joseph A.

1996-01-01

This study evaluates processes that affect nitrate concentrations in groundwater beneath riparian zones in an agricultural watershed. Nitrate pathways in the upper 2 m of groundwater were investigated beneath wooded and grass-shrub riparian zones next to cultivated fields. Because trees can be important components of the overall nitrate pathway in wooded riparian zones, water sources used by riparian trees and possible effects of trees on nitrate concentrations in groundwater were also investigated. Average nitrate concentrations in shallow groundwater beneath the cultivated fields were 5.5 mg/L upgradient of the wooded riparian zone and 3.5 mg/L upgradient of the grass-shrub zone. Shallow groundwater beneath the fields passed through the riparian zones and discharged into streams that had average nitrate concentrations of 8.5 mg/L (as N). Lateral variations of δD values in groundwater showed that mixing among different water sources occurred beneath the riparian zones. In the wooded riparian zone, nitrate concentrations in shallow groundwater were diluted by upwelling, nitrate-poor, deep groundwater. Upwelling deep groundwater contained ammonium with a δ15N of 5‰ that upon nitrification and mixing with nitrate in shallow groundwater caused nitrate δ15N values in shallow groundwater to decrease by as much as 19.5‰. Stream water penetrated laterally beneath the wooded riparian zone as far as 19 m from the stream's edge and beneath the grass-shrub zone as far as 27 m from the stream's edge. Nitrate concentrations in shallow groundwater immediately upgradient of where it mixed with stream water averaged 0.4 mg/L in the wooded riparian zone and 0.8 mg/L near the grass-shrub riparian zone. Nitrate concentrations increased toward the streams because of mixing with nitrate-rich stream water. Because nitrate concentrations were larger in stream water than shallow groundwater, concentrated nitrate in the streams cannot have come from shallow groundwater at these sites. Water sources of riparian trees were identified by comparing δD values of sap water, soil water, groundwater, and stream water. Soil water was the main water source for trees in the outer 4 to 6 m of one part of the wooded riparian zone and outer 10 m of another part. Groundwater was a significant water source for trees closer to the streams where the water table was less than about 2.1 to 2.7 m below the surface. No evidence was found in the nitrate concentration profiles that trees close to the streams that took up groundwater through their roots also took up nitrate from groundwater. The lack of such evidence is attributed to the nitrate concentration profiles being insufficiently sensitive indicators of nitrate removal by trees.

Factors Affecting Nitrate Delivery to Streams from Shallow Ground Water in the North Carolina Coastal Plain

USGS Publications Warehouse

Harden, Stephen L.; Spruill, Timothy B.

2008-01-01

An analysis of data collected at five flow-path study sites between 1997 and 2006 was performed to identify the factors needed to formulate a comprehensive program, with a focus on nitrogen, for protecting ground water and surface water in the North Carolina Coastal Plain. Water-quality protection in the Coastal Plain requires the identification of factors that affect the transport of nutrients from recharge areas to streams through the shallow ground-water system. Some basins process or retain nitrogen more readily than others, and the factors that affect nitrogen processing and retention were the focus of this investigation to improve nutrient management in Coastal Plain streams and to reduce nutrient loads to coastal waters. Nitrate reduction in ground water was observed at all five flow-path study sites in the North Carolina Coastal Plain, although the extent of reduction at each site was influenced by various environmental, hydrogeologic, and geochemical factors. Denitrification was the most common factor responsible for decreases in nitrate along the ground-water flow paths. Specific factors, some of which affect denitrification rates, that appeared to influence ground-water nitrate concentrations along the flow paths or in the streams include soil drainage, presence or absence of riparian buffers, evapotranspiration, fertilizer use, ground-water recharge rates and residence times, aquifer properties, subsurface tile drainage, sources and amounts of organic matter, and hyporheic processes. The study data indicate that the nitrate-reducing capacity of the buffer zone combined with that of the hyporheic zone can substantially lower the amount of ground-water nitrate discharged to streams in agricultural settings of the North Carolina Coastal Plain. At the watershed scale, the effects of ground-water discharge on surface-water quality appear to be greatly influenced by streamflow conditions and the presence of extensive riparian vegetation. Streamflow statistics that reflect base flow and the general hydrologic dynamics of a stream are important in understanding nutrient transport from a watershed and may be useful indicators of watersheds that are likely to have higher yields of nutrients and water. Combining streamflow statistics with information on such factors as land use, soil drainage, extent of riparian vegetation, geochemical conditions, and subsurface tile drainage in the Coastal Plain can be useful in identifying watersheds that are most likely to export excessive nitrogen due to nonpoint-source loadings and watersheds that are effective in processing nitrogen.

Transport and fate of nitrate and pesticides: Hydrogeology and riparian zone processes

USGS Publications Warehouse

Puckett, L.J.; Hughes, W.B.

2005-01-01

There is continuing concern over potential impacts of widespread application of nutrients and pesticides on ground- and surface-water quality. Transport and fate of nitrate and pesticides were investigated in a shallow aquifer and adjacent stream, Cow Castle Creek, in Orangeburg County, South Carolina. Pesticide and pesticide degradate concentrations were detected in ground water with greatest frequency and largest concentrations directly beneath and downgradient from the corn (Zea mays L.) field where they were applied. In almost all samples in which they were detected, concentrations of pesticide degradates greatly exceeded those of parent compounds, and were still present in ground waters that were recharged during the previous 18 yr. The absence of both parent and degradate compounds in samples collected from deeper in the aquifer suggests that this persistence is limited or that the ground water had recharged before use of the pesticide. Concentrations of NO3- in ground water decreased with increasing depth and age, but denitrification was not a dominant controlling factor. Hydrologic and chemical data indicated that ground water discharges to the creek and chemical exchange takes place within the upper 0.7 m of the streambed. Ground water had its greatest influence on surface-water chemistry during low-flow periods, causing a decrease in concentrations of Cl-, NO3-, pesticides, and pesticide degradates. Conversely, shallow subsurface drainage dominates stream chemistry during high-flow periods, increasing stream concentrations of Cl-, NO3-, pesticides, and pesticide degradates. These results point out the importance of understanding the hydrogeologic setting when investigating transport and fate of contaminants in ground water and surface water. ?? ASA, CSSA, SSSA.

Evaluation of Metal Toxicity in Streams Affected by Abandoned Mine Lands, Upper Animas River Watershed, Colorado

USGS Publications Warehouse

Besser, John M.; Allert, Ann L.; Hardesty, Douglas K.; Ingersoll, Christopher G.; May, Thomas W.; Wang, Ning; Leib, Kenneth J.

2001-01-01

Acid drainage from abandoned mines and from naturally-acidic rocks and soil in the upper Animas River watershed of Colorado generates elevated concentrations of acidity and dissolved metals in stream waters and deposition of metal-contaminated particulates in streambed sediments, resulting in both toxicity and habitat degradation for stream biota. High concentrations of iron (Fe), aluminum (Al), zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) occur in acid streams draining headwaters of the upper Animas River watershed, and high concentrations of some metals, especially Zn, persist in circumneutral reaches of the Animas River and Mineral Creek, downstream of mixing zones of acid tributaries. Seasonal variation of metal concentrations is reflected in variation in toxicity of stream water. Loadings of dissolved metals to the upper Animas River and tributaries are greatest during summer, during periods of high stream discharge from snowmelt and monsoonal rains, but adverse effects on stream biota may be greater during winter low-flow periods, when stream flows are dominated by inputs of groundwater and contain greatest concentrations of dissolved metals. Fine stream-bed sediments of the upper Animas River watershed also contain elevated concentrations of potentially toxic metals. Greatest sediment metal concentrations occur in the Animas River upstream from Silverton, where there are extensive deposits of mine and mill tailings, and in mixing zones in the Animas River and lower Mineral Creek, where precipitates of Fe and Al oxides also contain high concentrations of other metals. This report summarizes the findings of a series of toxicity studies in streams of the upper Animas River watershed, conducted on-site and in the laboratory between 1998 and 2000. The objectives of these studies were: (1) to determine the relative toxicity of stream water and fine stream-bed sediments to fish and invertebrates; (2) to determine the seasonal range of toxicity in stream water; (3) to develop site-specific thresholds for toxicity of Zn and Cu in stream water; and (4) to develop models of the contributions of Cu and Zn to toxicity of stream water, which may be used to characterize toxicity before and after planned remediation efforts. We evaluated the toxicity of metal-contaminated sediments by conducting sediment toxicity tests with two species of benthic invertebrates, the midge, Chironomus tentans. and the amphipod, Hyalella azteca. Laboratory toxicity tests with both taxa, exposed to fine stream-bed sediments collected in September 1997, showed some evidence of sediment toxicity, as survival of midge larvae in sediments from Cement Creek (C48) and lower Mineral Creek (M34), and growth of amphipods in sediments from these sites and three Animas River sites (A68, Animas at Silverton; A72, Animas below Silverton, and A73, Animas at Elk Park) were significantly reduced compared to a reference site, South Mineral Creek (SMC) . Amphipods were also exposed to site water and fine stream-bed sediment, separately and in combination, during the late summer low flow period (August-September) of 1998. In these studies, stream water, with no sediment present, from all five sites tested (same sites as above, except C48) caused 90% to 100% mortality of amphipods. In contrast, significant reductions in survival of amphipods occurred at two sites (A72 and SMC) in exposures with field-collected sediment plus stream water, and at only one site (A72) in exposures with sediments and clean overlying water. Concentrations of Zn, Pb, Cu, and Cd were high in both sediment and pore water (interstitial water) from most sites tested, but greatest sediment toxicity was apparently associated with greater concentrations of Fe and/or Al in sediments. These results suggest that fine stream-bed sediments of the more contaminated stream reaches of the upper Animas River watershed are toxic to benthic invertebrates, but that these impacts are less serious than tox

Effects of Land Use and Travel Time on the Distribution of Nitrate in the Kirkwood-Cohansey Aquifer System in Southern New Jersey

USGS Publications Warehouse

Kauffman, Leon J.; Baehr, Arthur L.; Ayers, Mark A.; Stackelberg, Paul E.

2001-01-01

Residents of the southern New Jersey Coastal Plain are increasingly reliant on the unconfined Kirkwood-Cohansey aquifer system for public water supply as a result of increasing population and restrictions on withdrawals from the deeper, confined aquifers. Elevated nitrate concentrations above background levels have been found in wells in the surficial aquifer system in agricultural and urban parts of this area. A three-dimensional steady-state ground-water-flow model of a 400-square-mile study area near Glassboro, New Jersey, was used in conjunction with particle tracking to examine the effects of land use and travel time on the distribution of nitrate in ground and surface water in southern New Jersey. Contributing areas and ground-water ages, or travel times, of water at ground-water discharge points (streams and wells) in the study area were simulated. Concentrations of nitrate were computed by linking land use and age-dependent nitrate concentrations in recharge to the discharge points. Median concentrations of nitrate in water samples collected during 1996 from shallow monitoring wells in different land-use areas were used to represent the concentration of nitrate in aquifer recharge since 1990. On the basis of upward trends in the use of nitrogen fertilizer, the concentrations of nitrate in aquifer recharge in agricultural and urban areas were assumed to have increased linearly from the background value in 1940 (0.07 mg/L as N) to the 1990 (2.5-14 mg/L as N) concentrations. Model performance was evaluated by comparing the simulation results to measured nitrate concentrations and apparent ground-water ages. Apparent ground-water ages at 32 monitoring wells in the study area determined from tritium/helium-3 ratios and sulfur hexafluoride concentrations favorably matched simulated travel times to these wells. Simulated nitrate concentrations were comparable to concentrations measured in 27 water-supply wells in the study area. A time series (1987-98) of nitrate concentrations at base-flow conditions in three streams that drain basins of various sizes and with various land uses was compared to simulated concentrations in these streams. In all three of the streams, a reasonable fit to the measured concentrations was achieved by multiplying the simulated concentration by 0.6. Because nitrate appeared to move conservatively (not degraded or adsorbed) in ground water to wells, the apparent non-conservative behavior in streams indicates that about 40 percent of the nitrate in aquifer recharge is removed by denitrification in the aquifer near the streams and (or) by in-stream processes. The model was used to evaluate the effects of various nitrate management options on the concentration of nitrate in streams and water-supply wells. Nitrate concentrations were simulated under the following management alternatives: an immediate ban on nitrate input, reduction of input at a constant rate, and fixed input at the current (2000) level. The time required for water to move through the aquifer results in a time lag between the reduction of nitrate input in recharge and the reduction of nitrate concentration in streams and wells. In the gradual-reduction alternative, nitrate concentrations in streams and wells continued to increase for several years after the reduction was enacted. In both the immediate-ban and gradual-reduction alternatives, nitrate concentrations remained elevated above background concentrations long after nitrate input ceased. In the fixed-use alternative, concentrations in streams and wells continued to increase for 30 to 40 years before reaching a constant level. The spatial distributions of simulated nitrate concentrations in streams in 2000 and 2050 were examined with the assumption of no change in land use, nitrate concentration in recharge, or ground-water withdrawals. As expected, nitrate concentrations were highest in agricultural areas and lowest in largely undeveloped areas. Changes in concentration

Environmental setting of benchmark streams in agricultural areas of eastern Wisconsin

USGS Publications Warehouse

Rheaume, S.J.; Stewart, J.S.; Lenz, B.N.

1996-01-01

Differences in land use/land cover, and riparian vegetation and instream habitat characteristics are presented. Summaries of field measurements of water temperature, pH, specific conductance and concentrations of dissolved oxygen, total organic plus ammonia nitrogen, dissolved ammonium, nitrate plus nitrte as nitrogen, total phosphorus, dissolved orthophosphate, and atrazine are listed. Concentrations of dissolved oxygen for the sampled streams ranged from 6 A to 14.3 and met the standards set by the Wisconsin Department of Natural Resources (WDNR) for supporting fish and aquatic life. Specific conductance ranged from 98 to 753 u,Scm with values highest in RHU's 1 and 3, where streams are underlain by carbonate bedrock. Median pH did not vary greatly among the four RHU's and ranged from 6.7 to 8.8 also meeting the WDNR standards. Concentrations of total organic plus ammonia nitrogen, dissolved ammonium, total phosphorus, and dissolved orthophosphate show little variation between streams and are generally low, compared to concentrations measured in agriculturally-affected streams in the same RHU's during the same sampling period. Concentrations of the most commonly used pesticide in the study unit, atrazine, were low in all streams, and most concentrations were below trn 0.1 u,g/L detection limit. Riparian vegetation for the benchmark streams were characterized by lowland species of the native plant communities described by John T. Curtis in the "Vegetation of Wisconsin." Based on the environmental setting and water-quality information collected to date, these streams appear to show minimal adverse effects from human activity.

Long-Term Trends in Nutrient Concentrations and Fluxes in Streams Draining to Lake Tahoe, California

NASA Astrophysics Data System (ADS)

Domagalski, J. L.

2017-12-01

Lake Tahoe, situated in the rain shadow of the eastern Sierra Nevada at an elevation of 1,897 meters, has numerous small to medium sized tributaries that are sources of nutrients and fine sediment. The Tahoe watershed is relatively small and the surface area of the lake occupies about 38% of the total watershed area (1,313 km2). Each stream contributing water to the lake therefore also occupies a small watershed, mostly forested, with typical trees being Jeffrey, Ponderosa, or Sugar Pine and White Fir. Outflow from the lake contributes to downstream uses such as water supply and ecological resources. Only about 6% of the watershed is urbanized or residential land, and wastewater is exported to adjacent basins and not discharged to the lake as part of a plan to maintain water clarity. The lake's exceptional clarity has been diminishing due to phytoplankton and fine sediment, prompting development of management plans to improve water quality. Much of the annual discharge and flux of nutrients to the lake results from snowmelt in the spring and summer months, and climatic changes have begun to shift this melt to earlier time frames. Winter rains on urbanized land also contribute to nutrient loads. To understand the relative importance of land use, climate, and other factors affecting stream concentrations and fluxes, a Weighted Regression on Time Discharge and Season (WRTDS) model documented trends over a time frame of greater than 25 years. Ten streams have records of discharge, nutrient (NO3, NH3, OP, TP, TKN) and sediment data to complete this analysis. Both urbanized and non-urbanized locations generally show NO3 trending down in the 1980s. Some locations show initially decreasing orthophosphate trends, followed by small significant increases in concentration and fluxes starting around 2000 to 2005. Although no wastewater enters the streams, ammonia concentrations mimic those of orthophosphate, with initially negative trends in concentration and flux followed by positive trends after 2005 through 2015. Those trends in ammonia are observed at most sites irrespective of the degree of urbanization and may be related to atmospheric transport of ammonia from outside of the basin. Continued monitoring of these streams is necessary to understand the implications of various management options on the lake.

Modeling sediment concentration of rill flow

NASA Astrophysics Data System (ADS)

Yang, Daming; Gao, Peiling; Zhao, Yadong; Zhang, Yuhang; Liu, Xiaoyuan; Zhang, Qingwen

2018-06-01

Accurate estimation of sediment concentration is essential to establish physically-based erosion models. The objectives of this study were to evaluate the effects of flow discharge (Q), slope gradient (S), flow velocity (V), shear stress (τ), stream power (ω) and unit stream power (U) on sediment concentration. Laboratory experiments were conducted using a 10 × 0.1 m rill flume under four flow discharges (2, 4, 8 and 16 L min-1), and five slope gradients (5°, 10°, 15°, 20° and 25°). The results showed that the measured sediment concentration varied from 87.08 to 620.80 kg m-3 with a mean value of 343.13 kg m-3. Sediment concentration increased as a power function with flow discharge and slope gradient, with R2 = 0.975 and NSE = 0.945. The sediment concentration was more sensitive to slope gradient than to flow discharge. The sediment concentration was well predicted by unit stream power (R2 = 0.937, NSE = 0.865), whereas less satisfactorily by flow velocity (R2 = 0.470, NSE = 0.539) and stream power (R2 = 0.773, NSE = 0.732). In addition, using the equations to simulate the measured sediment concentration of other studies, the result further indicated that slope gradient, flow discharge and unit stream power were good predictors of sediment concentration. In general, slope gradient, flow discharge and unit stream power seem to be the preferred predictors for estimating sediment concentration.

Delineation of geochemical anomalies based on stream sediment data utilizing fractal modeling and staged factor analysis

NASA Astrophysics Data System (ADS)

Afzal, Peyman; Mirzaei, Misagh; Yousefi, Mahyar; Adib, Ahmad; Khalajmasoumi, Masoumeh; Zarifi, Afshar Zia; Foster, Patrick; Yasrebi, Amir Bijan

2016-07-01

Recognition of significant geochemical signatures and separation of geochemical anomalies from background are critical issues in interpretation of stream sediment data to define exploration targets. In this paper, we used staged factor analysis in conjunction with the concentration-number (C-N) fractal model to generate exploration targets for prospecting Cr and Fe mineralization in Balvard area, SE Iran. The results show coexistence of derived multi-element geochemical signatures of the deposit-type sought and ultramafic-mafic rocks in the NE and northern parts of the study area indicating significant chromite and iron ore prospects. In this regard, application of staged factor analysis and fractal modeling resulted in recognition of significant multi-element signatures that have a high spatial association with host lithological units of the deposit-type sought, and therefore, the generated targets are reliable for further prospecting of the deposit in the study area.

Identifying pathways and processes affecting nitrate and orthophosphate inputs to streams in agricultural watersheds

USGS Publications Warehouse

Tesoriero, A.J.; Duff, J.H.; Wolock, D.M.; Spahr, N.E.; Almendinger, J.E.

2009-01-01

Understanding nutrient pathways to streams will improve nutrient management strategies and estimates of the time lag between when changes in land use practices occur and when water quality effects that result from these changes are observed. Nitrate and orthophosphate (OP) concentrations in several environmental compartments were examined in watersheds having a range of base flow index (BFI) values across the continental United States to determine the dominant pathways for water and nutrient inputs to streams. Estimates of the proportion of stream nitrate that was derived from groundwater increased as BFI increased. Nitrate concentration gradients between groundwater and surface water further supported the groundwater source of nitrate in these high BFI streams. However, nitrate concentrations in stream-bed pore water in all settings were typically lower than stream or upland groundwater concentrations, suggesting that nitrate discharge to streams was not uniform through the bed. Rather, preferential pathways (e.g., springs, seeps) may allow high nitrate groundwater to bypass sites of high biogeochemical transformation. Rapid pathway compartments (e.g., overland flow, tile drains) had OP concentrations that were typically higher than in streams and were important OP conveyers in most of these watersheds. In contrast to nitrate, the proportion of stream OP that is derived from ground water did not systematically increase as BFI increased. While typically not the dominant source of OP, groundwater discharge was an important pathway of OP transport to streams when BFI values were very high and when geochemical conditions favored OP mobility in groundwater. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Continuous aqueous tritium monitor

DOEpatents

McManus, G.J.; Weesner, F.J.

1987-10-19

An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture are selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration. 2 figs.

Element geochemical analysis of the contribution of aeolian sand to suspended sediment in desert stream flash floods.

PubMed

Jia, Xiaopeng; Wang, Haibing

2014-01-01

The interaction of wind and water in semiarid and arid areas usually leads to low-frequency flash flood events in desert rivers, which have adverse effects on river systems and ecology. In arid zones, many aeolian dune-fields terminate in stream channels and deliver aeolian sand to the channels. Although aeolian processes are common to many desert rivers, whether the aeolian processes contribute to fluvial sediment loss is still unknown. Here, we identified the aeolian-fluvial cycling process responsible for the high rate of suspended sediment transport in the Sudalaer desert stream in the Ordos plateau of China. On the basis of element geochemistry data analysis, we found that aeolian sand was similar to suspended sediment in element composition, which suggests that aeolian sand contributes to suspended sediment in flash floods. Scatter plots of some elements further confirm that aeolian sand is the major source of the suspended sediment. Factor analysis and the relation between some elements and suspended sediment concentration prove that the greater the aeolian process, the higher the suspended sediment concentration and the greater the contribution of aeolian sand to suspended sediment yield. We conclude that aeolian sand is the greatest contributor to flash floods in the Sudalaer desert stream.

Element Geochemical Analysis of the Contribution of Aeolian Sand to Suspended Sediment in Desert Stream Flash Floods

PubMed Central

Wang, Haibing

2014-01-01

The interaction of wind and water in semiarid and arid areas usually leads to low-frequency flash flood events in desert rivers, which have adverse effects on river systems and ecology. In arid zones, many aeolian dune-fields terminate in stream channels and deliver aeolian sand to the channels. Although aeolian processes are common to many desert rivers, whether the aeolian processes contribute to fluvial sediment loss is still unknown. Here, we identified the aeolian-fluvial cycling process responsible for the high rate of suspended sediment transport in the Sudalaer desert stream in the Ordos plateau of China. On the basis of element geochemistry data analysis, we found that aeolian sand was similar to suspended sediment in element composition, which suggests that aeolian sand contributes to suspended sediment in flash floods. Scatter plots of some elements further confirm that aeolian sand is the major source of the suspended sediment. Factor analysis and the relation between some elements and suspended sediment concentration prove that the greater the aeolian process, the higher the suspended sediment concentration and the greater the contribution of aeolian sand to suspended sediment yield. We conclude that aeolian sand is the greatest contributor to flash floods in the Sudalaer desert stream. PMID:25089295

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Wildcat Creek, Howard County, Indiana

USGS Publications Warehouse

Crawford, Charles G.; Wilber, William G.; Peters, James G.

1979-01-01

The Indiana State Board of Health is developing a water-quality management plan that includes establishing limits for wastewater effluents discharged into Indiana streams. A digital model calibrated to conditions in Wildcat Creek was used to predict alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. The model indicates that benthic-oxygen demand is the most significant factor affecting the dissolved-oxygen concentrations in Wildcat Creek during summer low flows. The Indiana stream dissolved-oxygen standard should not be violated if the Kokomo wastewater-treatment facility meets its current National Pollution Discharge Elimination System permit restrictions (average monthly 5-day biochemical-oxygen demand of 5 milligrams per liter and maximum weekly 5-day biochemical-oxygen demand of 7.5 milligrams per liter) and benthic-oxygen demand becomes negligible. Ammonia-nitrogen toxicity may also be a water-quality limitation in Wildcat Creek. Ammonia-nitrogen waste loads for the Kokomo wastewater-treatment facility, projected by the Indiana State Board of Health, will result in stream ammonia-nitrogen concentrations that exceed the State standard (2.5 milligrams per liter during summer months and 4.0 milligrams per liter during winter months). (Kosco-USGS)

The reclamation of Indian and Abrams creeks in Great Smoky Mountains National Park

USGS Publications Warehouse

Lennon, Robert E.; Parker, Phillip S.

1959-01-01

A complete program of stream reclamation was developed and applied on Indian and Abrams creeks in Great Smoky Mountains National Park. A salt-resistivity technique was used to estimate the dilution and velocity of a toxicant in running water. Streamside toxicity trials on resident fishes established minimal, effective concentrations of the rotenone material. The successful removals of undesirable fish were followed by restocking with selected strains of eastern brook trout and rainbow trout. Post-reclamation observations demonstrated enhanced survival, growth, reproduction, and catch of trout. Factors which might limit the effectiveness of stream reclamation programs ar e discussed.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Sand Creek, Decatur County, Indiana

USGS Publications Warehouse

Wilber, William G.; Crawford, Charles G.; Peters, James G.

1979-01-01

A digital model calibrated to conditions in Sand Creek near Greensburg, Ind., was used to develop alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. The only point-source waste load affecting Sand Creek in the vicinity of Greensburg is the Greensburg wastewater-treatment facility. Non-point, unrecorded waste loads seemed to be significant during three water-quality surveys done by the Indiana State Board of Health. Natural streamflow in Sand Creek during the summer and annual 7-day, 10-year low flow is zero so no benefit from dilution is provided. Effluent ammonia-nitrogen concentrations from the Greensburg wastewater-treatment facility will not meet Indiana water-quality standards during summer and winter low flows. To meet the water-quality standard the wastewater-effluent would be limited to a maximum total ammonia-nitrogen concentration of 2.5 mg/l for summer months (June through August) and 4.0 mg/l for winter months (November through March). Model simulations indicate that benthic-oxygen demand, nitrification, and the dissolved-oxygen concentration of the wastewater effluent are the most significant factors affecting the in-stream dissolved-oxygen concentration during summer low flows. The model predicts that with a benthic-oxygen demand of 1.5 grams per square meter per day at 20C the stream has no additional waste-load assimilative capacity. Present carbonaceous biochemical-oxygen demand loads from the Greensburg wastewater-treatment facility will not result in violations of the in-stream dissolved-oxygen standard (5 mg/l) during winter low flows. (Kosco-USGS)

Calibration and field application of passive sampling for episodic exposure to polar organic pesticides in streams.

PubMed

Fernández, Diego; Vermeirssen, Etiënne L M; Bandow, Nicole; Muñoz, Katherine; Schäfer, Ralf B

2014-11-01

Rainfall-triggered runoff is a major driver of pesticide input in streams. Only few studies have examined the suitability of passive sampling to quantify such episodic exposures. In this study, we used Empore™ styrene-divinylbenzene reverse phase sulfonated disks (SDB disks) and event-driven water samples (EDS) to assess exposure to 15 fungicides and 4 insecticides in 17 streams in a German vineyard area during 4 rainfall events. We also conducted a microcosm experiment to determine the SDB-disk sampling rates and provide a free-software solution to derive sampling rates under time-variable exposure. Sampling rates ranged from 0.26 to 0.77 L d(-1) and time-weighted average (TWA) concentrations from 0.05 to 2.11 μg/L. The 2 sampling systems were in good agreement and EDS exceeded TWA concentrations on average by a factor of 3. Our study demonstrates that passive sampling is suitable to quantify episodic exposures from polar organic pesticides. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of remediation on the bacterial community of an acid mine drainage impacted stream.

PubMed

Ghosh, Suchismita; Moitra, Moumita; Woolverton, Christopher J; Leff, Laura G

2012-11-01

Acid mine drainage (AMD) represents a global threat to water resources, and as such, remediation of AMD-impacted streams is a common practice. During this study, we examined bacterial community structure and environmental conditions in a low-order AMD-impacted stream before, during, and after remediation. Bacterial community structure was examined via polymerase chain reaction amplification of 16S rRNA genes followed by denaturing gradient gel electrophoresis. Also, bacterial abundance and physicochemical data (including metal concentrations) were collected and relationships to bacterial community structure were determined using BIO-ENV analysis. Remediation of the study stream altered environmental conditions, including pH and concentrations of some metals, and consequently, the bacterial community changed. However, remediation did not necessarily restore the stream to conditions found in the unimpacted reference stream; for example, bacterial abundances and concentrations of some elements, such as sulfur, magnesium, and manganese, were different in the remediated stream than in the reference stream. BIO-ENV analysis revealed that changes in pH and iron concentration, associated with remediation, primarily explained temporal alterations in bacterial community structure. Although the sites sampled in the remediated stream were in relatively close proximity to each other, spatial variation in community composition suggests that differences in local environmental conditions may have large impacts on the microbial assemblage.

Assessing the extent of nitrogen saturation in northern West Virginia forested watersheds: a survey of stream nitrate concentrations

Treesearch

Karl W. J. Williard; David R. DeWalle; Pamela J. Edwards

2003-01-01

Twenty-seven forested watersheds in northern West Virginia were sampled for stream nitrate concentrations during summer 1997 and fall 1998 baseflow periods to determine if Fernow watershed 4, an often-cited and studied nitrogen saturated basin, was anomalous or regionally representative in terms of stream nitrate levels. Baseflow stream NO3-N...

Do freshwater mussel shells record road-salt pollution?

NASA Astrophysics Data System (ADS)

O'Neil, Dane D.; Gillikin, David P.

2014-11-01

Road-salt pollution in streams in the Northeastern United States has become a major concern, but historical data are scarce. Freshwater bivalve shells have the ability to record past environmental information, and may act as archives of road-salt pollution. We sampled Elliptio complanata shells from four streams, as well as specimens collected in 1877. Average [Na/Ca]shell was highest in modern shells from the stream with the highest sodium concentrations, and low in shells collected from this same stream in 1877 as well as in the shells from other streams, suggesting that [Na/Ca]shell serves as a proxy for road-salt pollution. We expected higher [Na/Ca]shell in winter and spring. However, high-resolution [Na/Ca]shell analyses along the growth axis of one shell did not reveal any clear subannual patterns, which could be the result of shell growth cessation in winter and/or during periods of high stream sodium concentrations. Therefore, bulk [Na/Ca]shell analysis from multiple shells can be used as a proxy of large changes in stream sodium concentrations, but high-resolution variations in stream sodium concentrations do not seem to be recorded in the shells.

Do freshwater mussel shells record road-salt pollution?

PubMed Central

O'Neil, Dane D.; Gillikin, David P.

2014-01-01

Road-salt pollution in streams in the Northeastern United States has become a major concern, but historical data are scarce. Freshwater bivalve shells have the ability to record past environmental information, and may act as archives of road-salt pollution. We sampled Elliptio complanata shells from four streams, as well as specimens collected in 1877. Average [Na/Ca]shell was highest in modern shells from the stream with the highest sodium concentrations, and low in shells collected from this same stream in 1877 as well as in the shells from other streams, suggesting that [Na/Ca]shell serves as a proxy for road-salt pollution. We expected higher [Na/Ca]shell in winter and spring. However, high-resolution [Na/Ca]shell analyses along the growth axis of one shell did not reveal any clear subannual patterns, which could be the result of shell growth cessation in winter and/or during periods of high stream sodium concentrations. Therefore, bulk [Na/Ca]shell analysis from multiple shells can be used as a proxy of large changes in stream sodium concentrations, but high-resolution variations in stream sodium concentrations do not seem to be recorded in the shells. PMID:25418687

Method of immobilizing carbon dioxide from gas streams

DOEpatents

Holladay, David W.; Haag, Gary L.

1979-01-01

This invention is a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to barium carbonate. The method has several important advantages: it can be conducted effectively at ambient temperature; it provides a very rapid reaction rate over a wide range of carbon dioxide concentrations; it provides high decontamination factors; and it has a high capacity for carbon dioxide. The invention is especially well suited for the removal of radioactive carbon dioxide from off-gases generated by nuclear-fuel reprocessing facilities and nuclear power plants.

Pesticide toxicity index for freshwater aquatic organisms

USGS Publications Warehouse

Munn, Mark D.; Gilliom, Robert J.

2001-01-01

The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 75 of the 83 pesticide compounds measured in NAWQA samples, but with a wide range of bioassays per compound (1 to 65). There were a total of 2,824 bioassays for the 75 compounds, including 287 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a nonlethal response) for freshwater cladocerans, 585 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 1,952 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups.While the PTI does not determine whether water in a sample is toxic, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or additional assessments. The PTI approach may be useful as a basis for comparing the potential significance of pesticides in different streams on a common basis, for evaluating relations between pesticide exposure and observed biological conditions, and for prioritizing where further studies are most needed.

Determination of dilution factors for discharge of aluminum-containing wastes by public water-supply treatment facilities into lakes and reservoirs in Massachusetts

USGS Publications Warehouse

Colman, John A.; Massey, Andrew J.; Brandt, Sara L.

2011-09-16

Dilution of aluminum discharged to reservoirs in filter-backwash effluents at water-treatment facilities in Massachusetts was investigated by a field study and computer simulation. Determination of dilution is needed so that permits for discharge ensure compliance with water-quality standards for aquatic life. The U.S. Environmental Protection Agency chronic standard for aluminum, 87 micrograms per liter (μg/L), rather than the acute standard, 750 μg/L, was used in this investigation because the time scales of chronic exposure (days) more nearly match rates of change in reservoir concentrations than do the time scales of acute exposure (hours).Whereas dilution factors are routinely computed for effluents discharged to streams solely on the basis of flow of the effluent and flow of the receiving stream, dilution determination for effluents discharged to reservoirs is more complex because (1), compared to streams, additional water is available for dilution in reservoirs during low flows as a result of reservoir flushing and storage during higher flows, and (2) aluminum removal in reservoirs occurs by aluminum sedimentation during the residence time of water in the reservoir. Possible resuspension of settled aluminum was not considered in this investigation. An additional concern for setting discharge standards is the substantial concentration of aluminum that can be naturally present in ambient surface waters, usually in association with dissolved organic carbon (DOC), which can bind aluminum and keep it in solution.A method for dilution determination was developed using a mass-balance equation for aluminum and considering sources of aluminum from groundwater, surface water, and filter-backwash effluents and losses caused by sedimentation, water withdrawal, and spill discharge from the reservoir. The method was applied to 13 reservoirs. Data on aluminum and DOC concentrations in reservoirs and influent water were collected during the fall of 2009. Complete reservoir volume was determined to be available for mixing on the basis of vertical and horizontal aluminum-concentration profiling. Losses caused by settling of aluminum were assumed to be proportional to aluminum concentration and reservoir area. The constant of proportionality, as a function of DOC concentration, was established by simulations in each of five reservoirs that differed in DOC concentration.In addition to computing dilution factors, the project determined dilution factors that would be protective with the same statistical basis (frequency of exceedance of the chronic standard) as dilutions computed for streams at the 7-day-average 10-year-recurrence annual low flow (the 7Q10). Low-flow dilutions are used for permitting so that receiving waters are protected even at the worst-case flow levels. The low-flow dilution factors that give the same statistical protection are the lowest annual 7-day-average dilution factors with a recurrence of 10 years, termed 7DF10s. Determination of 7DF10 values for reservoirs required that long periods of record be simulated so that dilution statistics could be determined. Dilution statistics were simulated for 13 reservoirs from 1960 to 2004 using U.S. Geological Survey Firm-Yield Estimator software to model reservoir inputs and outputs and present-day values of filter-effluent discharge and aluminum concentration.Computed settling velocities ranged from 0 centimeters per day (cm/d) at DOC concentrations of 15.5 milligrams per liter (mg/L) to 21.5 cm/d at DOC concentrations of 2.7 mg/L. The 7DF10 values were a function of aluminum effluent discharged. At current (2009) effluent discharge rates, the 7DF10 values varied from 1.8 to 115 among the 13 reservoirs. In most cases, the present-day (2009) discharge resulted in receiving water concentrations that did not exceed the standard at the 7DF10. Exceptions were one reservoir with a very small area and three reservoirs with high concentrations of DOC. Maximum permissible discharges were determined for water-treatment plants by adjusting discharges upward in simulations until the 7DF10 resulted in reservoir concentrations that just met the standard. In terms of aluminum flux, these discharges ranged from 0 to 28 kilograms of aluminum per day.

Regulation of stream water dissolved organic carbon concentrations ([DOC]) during snowmelt in forest streams; the role of discharge, winter climate and memory effects

NASA Astrophysics Data System (ADS)

Ågren, A.; Haei, M.; Öquist, M.; Buffam, I.; Ottosson-Löfvenius, M.; Kohler, S.; Bishop, K.; Blomkvist, P.; Laudon, H.

2011-12-01

Using 15 year stream records from two forested northern boreal catchments, coupled with soil frost experiments in the riparian zone, we demonstrate the complex inter-annual control on [DOC] and export during snowmelt. Stream [DOC] varied by a factor of 2 during those 15 years with no consistent trend. Based on our long-term analysis, we demonstrate, for the first time, that stream water [DOC] is strongly linked to the climatic conditions during the preceding winter, but that there is also a long-term memory effect in the catchment soils, related to the extent of the previous export from the catchment. Hydrology had a first order control on the inter-annual variation in concentrations, and the length of the winter was more important than the memory effect. By removing the effect of discharge on [DOC], using a conceptual hydrological model, we could detect processes that would otherwise have been overshadowed. A short and intense snowmelt gave higher [DOC] in the stream. During a prolonged snowmelt, one soil layer at the time might have been "flushed" from easily exported DOC, resulting in slightly lower stream [DOC] during such years. We found that longer and colder winters resulted in higher [DOC] during the subsequent snowmelt. A soil frost manipulation experiment in the riparian soils of the study catchment showed that the DOC concentrations in the soil water increased with the duration of the soil frost. A high antecedent DOC export during the preceding summer and autumn resulted in lower concentrations during the following spring, indicating a long-term "memory effect" of the catchment soils. In a nearby stream draining mire, we found a different response to hydrology but similar response to climate and memory effect. The inter-annual variation in snowmelt DOC exports was mostly controlled by the amount of runoff, but the variability in [DOC] also exerted a significant control on the exports, accounting for 15% of the variance in exports. We conclude that winter climatic conditions can play a substantial role in controlling stream [DOC] in ways not previously understood. These findings are especially important for northern latitude regions expected to be most affected by climate change. It's difficult to directly translate this to a future climate change prediction. If warmer winters with less insulating snow cover increase the soil frost, the results from the soil frost manipulation experiment then suggest increasing [DOC] in a future climate. At the same time the statistical analysis of the stream records suggest that a shorter and warmer winter would decrease the [DOC]. Our results do, however, highlight the role of winter climate for regulating DOC in areas with seasonally frozen soils which should be considered when resolving the sensitivity of stream [DOC] to global environmental change.

Variations in land use and nonpoint-source contamination on the Fort Berthold Indian Reservation, west-central North Dakota, 1990-93

USGS Publications Warehouse

Macek-Rowland, Kathleen; Lent, Robert M.

1996-01-01

The effects of land-use activities on the water quality of five streams on the Fort Berthold Indian Reservation were evaluated. The five basinsevaluated were East Fork Shell Creek, Deepwater Creek, Bear Den Creek, Moccasin Creek, and Squaw Creek. East Fork Shell Creek and DeepwaterCreek Basins are located east of Lake Sakakawea and Bear Den Creek, Moccasin Creek, and Squaw Creek Basins are located west of the lake. Land-use data for the five selected basins on and adjacent to the Fort Berthold Indian Reservation were obtained for 1990-92. Discharge measurements were made and water-quality samples were collected at stations and sites on each of the five streams during October 1991 through September 1993. Analysis of land-use data indicated that prairie was the largest land-use category in the study area. More prairie acreage was found in the basins located west of Lake Sakakawea than in the basins located east of the lake. Wheat was the predominant crop in the study area. More wheat acreage was found in the basins located east of Lake Sakakawea than in the basins located west of the lake. Discharge data for the five selected streams indicated that all of thestreams were ephemeral and had many days of no flow during the study period. High flows were usually the result of spring runoff or intense storms over the basins. East Fork Shell Creek and Deepwater Creek with larger basins and flatter stream slopes had high flows characterized by rapidly rising flows and gradually receding flows. In contrast, Bear DenCreek, Moccasin Creek, and Squaw Creek with smaller basins and steeper stream slopes had high flows characterized by rapidly rising flows and receding flows of shorter duration. Analysis of water-quality samples indicated concentrations of nitrogen, phosphorus, and total organic carbon varied throughout the study area. Nitrogen concentrations were larger in the streams located east of LakeSakakawea than in the streams located west of the lake. The largest nitrogen concentrations in all of the streams occurred during the nongrowing periods.Phosphorus (orthophosphate and total phosphorus)concentrations were larger in the streams located east of Lake Sakakawea than in the streams located west of the lake. The larger orthophosphateconcentrations in the eastern streams may be indicative of insecticide application in the eastern streams' basins. Total organic carbon concentrations were fairly consistent in all five streams. Water-quality samples were analyzed for the pesticides atrazine, carbofuran, cyanazine, and 2,4-D by using immunoassay testing. Pesticide concentrations above the minimum reporting levels were more prevalent insamples from streams located east of Lake Sakakawea than in the streams located west of the lake. The eastern streams drain areas where herbicides were applied to crops. Fecal-bacteria concentrations were larger in the streams located west of Lake Sakakawea, where prairie is more dominant, than in the streams located east of the lake. The larger concentrations and loads were associated with intense storm events and the presence of livestock.

Water-quality assessment of the Ozark Plateaus study unit, Arkansas, Kansas, Missouri, and Oklahoma; nutrients, bacteria, organic carbon, and suspended sediment in surface water, 1993-95

USGS Publications Warehouse

Davis, Jerri V.; Bell, Richard W.

1998-01-01

Nutrient, bacteria, organic carbon, and suspended- sediment samples were collected from 1993-95 at 43 surface-water-quality sampling sites within the Ozark Plateaus National Water- Quality Assessment Program study unit. Most surface-water-quality sites have small or medium drainage basins, near-homogenous land uses (primarily agricultural or forest), and are located predominantly in the Springfield and Salem Plateaus. The water-quality data were analyzed using selected descriptive and statistical methods to determine factors affecting occurrence in streams in the study unit. Nitrogen and phosphorus fertilizer use increased in the Ozark Plateaus study unit for the period 1965-85, but the application rates are well below the national median. Fertilizer use differed substantially among the major river basins and physiographic areas in the study unit. Livestock and poultry waste is a major source of nutrient loading in parts of the study unit. The quantity of nitrogen and phosphorus from livestock and poultry wastes differed substantially among the river basins of the study unit's sampling network. Eighty six municipal sewage-treatment plants in the study unit have effluents of 0.5 million gallons per day or more (for the years 1985-91). Statistically significant differences existed in surface-water quality that can be attributed to land use, physiography, and drainage basin size. Dissolved nitrite plus nitrate, total phosphorus, fecal coliform bacteria, and dissolved organic carbon concentrations generally were larger at sites associated with agricultural basins than at sites associated with forested basins. A large difference in dissolved nitrite plus nitrate concentrations occurred between streams draining basins with agricultural land use in the Springfield and Salem Plateaus. Streams draining both small and medium agricultural basins in the Springfield Plateau had much larger concentrations than their counterparts in the Salem Plateau. Drainage basin size was not a significant factor in affecting total phosphorus, fecal coliform bacteria, or dissolved organic carbon concentrations. Suspended-sediment concentrations generally were small and indicative of the clear water in streams in the Ozark Plateaus. A comparison of the dissolved nitrite plus nitrate, total phosphorus, and fecal coliform data collected at the fixed and synoptic sites indicates that generally the data for streams draining basins of similar physiography, land-use setting, and drainage basin size group together. Many of the variations are most likely the result of differences in percent agricultural land use between the sites being compared or are discharge related. The relation of dissolved nitrite plus nitrate, total phosphorus, and fecal coliform concentration to percent agricultural land use has a strong positive 2 Water-Quality Assessment-Nutrients, Bacteria, Organic Carbon, and Suspended Sediment in Surface Water, 1993-95 correlation, with percent agricultural land use accounting for between 42 and 60 percent of the variation in the observed concentrations.

Percentile Distributions of Median Nitrite Plus Nitrate as Nitrogen, Total Nitrogen, and Total Phosphorus Concentrations in Oklahoma Streams, 1973-2001

USGS Publications Warehouse

Haggard, Brian E.; Masoner, Jason R.; Becker, Carol J.

2003-01-01

Nutrients are one of the primary causes of water-quality impairments in streams, lakes, reservoirs, and estuaries in the United States. The U.S. Environmental Protection Agency has developed regional-based nutrient criteria using ecoregions to protect streams in the United States from impairment. However, nutrient criteria were based on nutrient concentrations measured in large aggregated nutrient ecoregions with little relevance to local environmental conditions in states. The Oklahoma Water Resources Board is using a dichotomous process known as Use Support Assessment Protocols to define nutrient criteria in Oklahoma streams. The Oklahoma Water Resources Board is modifying the Use Support Assessment Protocols to reflect nutrient informa-tion and environmental characteristics relevant to Oklahoma streams, while considering nutrient information grouped by geographic regions based on level III ecoregions and state boundaries. Percentile distributions of median nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorous concentrations were calculated from 563 sites in Oklahoma and 4 sites in Arkansas near the Oklahoma and Arkansas border to facilitate development of nutrient criteria for Oklahoma streams. Sites were grouped into four geographic regions and were categorized into eight stream categories by stream slope and stream order. The 50th percentiles of median nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorus concentrations were greater in the Ozark Highland ecoregion and were less in the Ouachita Mountains ecoregion when compared to other geographic areas used to group sites. The 50th percentiles of median concentrations of nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorus were least in first, second, and third order streams. The 50th percentiles of median nitrite plus nitrate as nitrogen, total nitrogen and total phosphorus concentrations in the Ozark Highland and Ouachita Mountains ecoregions were least in first, second, and third order streams with streams slopes greater than 17 feet per mile. Nitrite plus nitrate as nitrogen and total nitrogen criteria determined by the U.S. Environmental Protection Agency for the Ozark Highland ecoregion were less than the 25th percentiles of median nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorus concentrations in the Ozark Highland ecoregion calculated for this report. Nitrite plus nitrate as nitrogen and total nitrogen criteria developed by the U.S. Environmental Protection Agency for the Ouachita Mountains ecoregion were similar to the 25th percentiles of median nitrite plus nitrate as nitrogen and total nitrogen concentrations in the Ouachita Mountains ecoregion calculated for this report. Nitrate as nitrogen and total phosphorus concentrations currently (2002) used in the Use Support Assessment Protocols for Oklahoma were greater than the 75th percentiles of median nitrite plus nitrate as nitrogen and total phosphorus concentrations calculated for this report.

Hydro-climatic control of stream dissolved organic carbon in headwater catchment

NASA Astrophysics Data System (ADS)

Humbert, Guillaume; Jaffrezic, Anne; Fovet, Ophélie; Gruau, Gérard; Durand, Patrick

2014-05-01

Dissolved organic matter (DOM) is a key form of the organic matter linking together the water and the carbon cycles and interconnecting the biosphere (terrestrial and marine) and the soil. At the landscape scale, land use and hydrology are the main factors controlling the amount of DOM transferred from soils to the stream. In an intensively cultivated catchment, a recent work using isotopic composition of DOM as a marker has identified two different sources of DOM. The uppermost soil horizons of the riparian wetland appear as a quasi-infinite source while the topsoil of the hillslope forms a limited one mobilized by water-table rise and exported to the stream across the upland-riparian wetland-stream continuum. In addition to the exportation of DOM via water fluxes, climatic factors like temperature and precipitation regulate the DOM production by influencing microbial activity and soil organic matter degradation. The small headwater catchment (5 km²) of Kervidy-Naizin located in Brittany is part of the Environment Research Observatory (ORE) AgrHys. Weather and the hydro-chemistry of the stream, and the groundwater levels are daily recorded since 1993, 2000 and 2001 respectively. Over 13 contrasted hydrological years, the annual flow weighted mean concentration of dissolved organic carbon (DOC) is 5.6 mg.L-1 (sd = 0.7) for annual precipitation varying from 488mm to 1327mm and annual mean temperatures of 11°C (sd = 0.6). Based on this considerable dataset and this annual variability, we tried to understand how the hydro-climatic conditions determinate the stream DOC concentrations along the year. From the fluctuations of water table depth, each hydrologic year has been divided into three main period: i) progressive rewetting of the riparian wetland soils, ii) rising and holding high of the water table in the hillslope, iii) drawdown of the water-table, with less and less topsoil connected to the stream. Within each period base flow and storm flow data were first pooled then treated separately and the influence of preceding periods was tested. This hydrological division of time allowed us to identify climate effect on the topsoil DOM stores of the wetland and hillslope separately. Meteorological and hydro-pedological variables, like soil temperatures or duration of the water saturation in the organo-mineral horizons have been used to interpret the DOC concentrations and fluxes at the outlet within each period. The three hydrological periods contribute respectively to less than 17%, more than 63%, and less than 26% of the annual DOM exportation with flow weighted mean concentration of DOC of 9.5, 6.1, and 3.8 mg.L-1. Considering several DOM sources with different properties of depletion under climatic control, the main output of the work is to provide a modified conceptual model of the DOC dynamics.

Comparison of pesticides in eight U.S. urban streams

USGS Publications Warehouse

Hoffman, R.S.; Capel, P.D.; Larson, S.J.

2000-01-01

Little is known of the occurrence of pesticides in urban streams compared to streams draining agricultural areas. Water samples from eight urban streams from across the United States were analyzed for 75 pesticides and seven transformation products. For six of the eight urban streams, paired agricultural streams were used for comparisons. The herbicides detected most frequently in the urban streams were prometon, simazine, atrazine, tebuthiuron, and metolachlor, and the insecticides detected most frequently were diazinon, carbaryl, chlorpyrifos, and malathion. In contrast to similar-sized agricultural streams, total insecticide concentrations commonly exceeded total herbicide concentrations in these urban streams. In general, the temporal concentration patterns in the urban streams were consistent with the characteristics of the local growing season. The insecticides carbaryl and diazinon exceeded criteria for the protection of aquatic life in many of the urban streams in the spring and summer. When the country as a whole is considered, the estimated mass of herbicides contributed by urban areas to streams is dwarfed by the estimated contribution from agricultural areas, but for insecticides, contributions from urban and agricultural areas may be similar. The results of this study suggest that urban areas should not be overlooked when assessing sources and monitoring the occurrence of pesticides in surface waters.

Estimating Discharge and Nonpoint Source Nitrate Loading to Streams From Three End-Member Pathways Using High-Frequency Water Quality Data

NASA Astrophysics Data System (ADS)

Miller, Matthew P.; Tesoriero, Anthony J.; Hood, Krista; Terziotti, Silvia; Wolock, David M.

2017-12-01

The myriad hydrologic and biogeochemical processes taking place in watersheds occurring across space and time are integrated and reflected in the quantity and quality of water in streams and rivers. Collection of high-frequency water quality data with sensors in surface waters provides new opportunities to disentangle these processes and quantify sources and transport of water and solutes in the coupled groundwater-surface water system. A new approach for separating the streamflow hydrograph into three components was developed and coupled with high-frequency nitrate data to estimate time-variable nitrate loads from chemically dilute quick flow, chemically concentrated quick flow, and slowflow groundwater end-member pathways for periods of up to 2 years in a groundwater-dominated and a quick-flow-dominated stream in central Wisconsin, using only streamflow and in-stream water quality data. The dilute and concentrated quick flow end-members were distinguished using high-frequency specific conductance data. Results indicate that dilute quick flow contributed less than 5% of the nitrate load at both sites, whereas 89 ± 8% of the nitrate load at the groundwater-dominated stream was from slowflow groundwater, and 84 ± 25% of the nitrate load at the quick-flow-dominated stream was from concentrated quick flow. Concentrated quick flow nitrate concentrations varied seasonally at both sites, with peak concentrations in the winter that were 2-3 times greater than minimum concentrations during the growing season. Application of this approach provides an opportunity to assess stream vulnerability to nonpoint source nitrate loading and expected stream responses to current or changing conditions and practices in watersheds.

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

USGS Publications Warehouse

Ciparis, S.; Iwanowicz, L.R.; Voshell, J.R.

2012-01-01

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO 4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17??-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1ng/L. Relatively high concentrations of DIN (>1000??g/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R 2=0.56-0.81) and E2Eq (R 2=0.39-0.75). Relationships between watershed densities of AFOs and PO 4-P were weaker, but were also significant (R 2=0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO 4-P than streams without WWTP discharges, and PO 4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. ?? 2011 Elsevier B.V.

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

USGS Publications Warehouse

Ciparis, Serena; Iwanowicz, Luke R.; Voshell, J. Reese

2012-01-01

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations > 1 ng/L. Relatively high concentrations of DIN (> 1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R2 = 0.56–0.81) and E2Eq (R2 = 0.39–0.75). Relationships between watershed densities of AFOs and PO4-P were weaker, but were also significant (R2 = 0.27–0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO4-P than streams without WWTP discharges, and PO4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms.

Fallout volume and litter type affect 137Cs concentration difference in litter between forest and stream environments.

PubMed

Sakai, Masaru; Gomi, Takashi; Negishi, Junjiro N

2016-11-01

It is important to understand the changes in the 137 Cs concentration in litter through leaching when considering that 137 Cs is transferred from basal food resources to animals in forested streams. We found that the difference of 137 Cs activity concentration in litter between forest and stream was associated with both litter type and 137 Cs fallout volume around Fukushima, Japan. The 137 Cs activity concentrations in the litter of evergreen conifers tended to be greater than those in the litter of broad-leaved deciduous trees because of the absence of deciduous leaves during the fallout period in March 2011. Moreover, 137 Cs activity concentrations in forest litter were greater with respect to the 137 Cs fallout volume. The 137 Cs activity concentrations in stream litter were much lower than those in forest litter when those in forest litter were higher. The 137 Cs leaching patterns indicated that the differences in 137 Cs activity concentration between forest and stream litter could change with changes in both fallout volume and litter type. Because litter is an important basal food resource in the food webs of both forests and streams, the 137 Cs concentration gradient reflects to possible 137 Cs transfer from lower to higher trophic animals. Our findings will improve our understanding of the spatial heterogeneity and variability of 137 Cs concentrations in animals resident to the contaminated landscape. Copyright © 2016 Elsevier Ltd. All rights reserved.

Temperature Effect on the Sorption of Radionuclides by Freshwater Algae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, R.S.

2003-01-06

The heavy waters of the reactor effluent streams within the Savannah River Plant area transport very low concentrations of fission and activation products through miles of natural streambeds and swamps to the Savannah River. This study emphasizes the effects of environmental factors on the sorption of radionuclides by representative species.

NITRATE AND NITROUS OXIDE CONCENTRATIONS IN SMALL STREAMS OF THE GEORGIA PIEDMONT

EPA Science Inventory

We are measuring dissolved nitrate and nitrous oxide concentrations and related parameters in 17 headwater streams in the South Fork Broad River, Georgia watershed on a monthly basis. The selected small streams drain watersheds dominated by forest, pasture, residential, or mixed...

Widespread detection of N,N-diethyl-m-toluamide in U.S. streams: Comparison with concentrations of pesticides, personal care products, and other organic wastewater compounds

USGS Publications Warehouse

Sandstrom, M.W.; Kolpin, D.W.; Thurman, E.M.; Zaugg, S.D.

2005-01-01

One of the most frequently detected organic chemicals in a nationwide study concerning the effects of wastewater on stream water quality conducted in the year 2000 was the widely used insect repellant N,N-diethyl-m-toluamide (DEET). It was detected at levels of 0.02 μg/L or greater in 73% of the stream sites sampled, with the selection of sampling sites being biased toward streams thought to be subject to wastewater contamination (i.e., downstream from intense urbanization and livestock production). Although DEET frequently was detected at all sites, the median concentration was low (0.05 μg/L). The highest concentrations of DEET were found in streams from the urban areas (maximum concentration, 1.1 μg/L). The results of the present study suggest that the movement of DEET to streams through wastewater-treatment systems is an important mechanism that might lead to the exposure of aquatic organisms to this chemical.

Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams

USGS Publications Warehouse

Nowell, Lisa H.; Moran, Patrick W.; Schmidt, Travis S.; Norman, Julia E.; Nakagaki, Naomi; Shoda, Megan E.; Mahler, Barbara J.; Van Metre, Peter C.; Stone, Wesley W.; Sandstrom, Mark W.; Hladik, Michelle L.

2018-01-01

Aquatic organisms in streams are exposed to pesticide mixtures that vary in composition over time in response to changes in flow conditions, pesticide inputs to the stream, and pesticide fate and degradation within the stream. To characterize mixtures of dissolved-phase pesticides and degradates in Midwestern streams, a synoptic study was conducted at 100 streams during May–August 2013. In weekly water samples, 94 pesticides and 89 degradates were detected, with a median of 25 compounds detected per sample and 54 detected per site. In a screening-level assessment using aquatic-life benchmarks and the Pesticide Toxicity Index (PTI), potential effects on fish were unlikely in most streams. For invertebrates, potential chronic toxicity was predicted in 53% of streams, punctuated in 12% of streams by acutely toxic exposures. For aquatic plants, acute but likely reversible effects on biomass were predicted in 75% of streams, with potential longer-term effects on plant communities in 9% of streams. Relatively few pesticides in water—atrazine, acetochlor, metolachlor, imidacloprid, fipronil, organophosphate insecticides, and carbendazim—were predicted to be major contributors to potential toxicity. Agricultural streams had the highest potential for effects on plants, especially in May–June, corresponding to high spring-flush herbicide concentrations. Urban streams had higher detection frequencies and concentrations of insecticides and most fungicides than in agricultural streams, and higher potential for invertebrate toxicity, which peaked during July–August. Toxicity-screening predictions for invertebrates were supported by quantile regressions showing significant associations for the Benthic Invertebrate-PTI and imidacloprid concentrations with invertebrate community metrics for MSQA streams, and by mesocosm toxicity testing with imidacloprid showing effects on invertebrate communities at environmentally relevant concentrations. This study documents the most complex pesticide mixtures yet reported in discrete water samples in the U.S. and, using multiple lines of evidence, predicts that pesticides were potentially toxic to nontarget aquatic life in about half of the sampled streams.

Effects of Land Use and Land Cover, Stream Discharge, and Interannual Climate on the Magnitude and Timing of Nitrogen, Phosphorus, and Organic Carbon Concentrations in Three Coastal Plain Watersheds

EPA Science Inventory

In-stream nitrogen, phosphorus, organic carbon, and suspended sediment concentrations were measured in 18 sub-basins over two annual cycles to assess how land-use/land-cover (LULC) and stream discharge regulate water quality variables. LULC was a primary driver of in-stream const...

Contamination with bacterial zoonotic pathogen genes in U.S. streams influenced by varying types of animal agriculture.

PubMed

Haack, Sheridan K; Duris, Joseph W; Kolpin, Dana W; Focazio, Michael J; Meyer, Michael T; Johnson, Heather E; Oster, Ryan J; Foreman, William T

2016-09-01

Animal waste, stream water, and streambed sediment from 19 small (<32km(2)) watersheds in 12U.S. states having either no major animal agriculture (control, n=4), or predominantly beef (n=4), dairy (n=3), swine (n=5), or poultry (n=3) were tested for: 1) cholesterol, coprostanol, estrone, and fecal indicator bacteria (FIB) concentrations, and 2) shiga-toxin producing and enterotoxigenic Escherichia coli, Salmonella, Campylobacter, and pathogenic and vancomycin-resistant enterococci by polymerase chain reaction (PCR) on enrichments, and/or direct quantitative PCR. Pathogen genes were most frequently detected in dairy wastes, followed by beef, swine and poultry wastes in that order; there was only one detection of an animal-source-specific pathogen gene (stx1) in any water or sediment sample in any control watershed. Post-rainfall pathogen gene numbers in stream water were significantly correlated with FIB, cholesterol and coprostanol concentrations, and were most highly correlated in dairy watershed samples collected from 3 different states. Although collected across multiple states and ecoregions, animal-waste gene profiles were distinctive via discriminant analysis. Stream water gene profiles could also be discriminated by the watershed animal type. Although pathogen genes were not abundant in stream water or streambed samples, PCR on enrichments indicated that many genes were from viable organisms, including several (shiga-toxin producing or enterotoxigenic E. coli, Salmonella, vancomycin-resistant enterococci) that could potentially affect either human or animal health. Pathogen gene numbers and types in stream water samples were influenced most by animal type, by local factors such as whether animals had stream access, and by the amount of local rainfall, and not by studied watershed soil or physical characteristics. Our results indicated that stream water in small agricultural U.S. watersheds was susceptible to pathogen gene inputs under typical agricultural practices and environmental conditions. Pathogen gene profiles may offer the potential to address both source of, and risks associated with, fecal pollution. Published by Elsevier B.V.

Method for processing aqueous wastes

DOEpatents

Pickett, J.B.; Martin, H.L.; Langton, C.A.; Harley, W.W.

1993-12-28

A method is presented for treating waste water such as that from an industrial processing facility comprising the separation of the waste water into a dilute waste stream and a concentrated waste stream. The concentrated waste stream is treated chemically to enhance precipitation and then allowed to separate into a sludge and a supernate. The supernate is skimmed or filtered from the sludge and blended with the dilute waste stream to form a second dilute waste stream. The sludge remaining is mixed with cementitious material, rinsed to dissolve soluble components, then pressed to remove excess water and dissolved solids before being allowed to cure. The dilute waste stream is also chemically treated to decompose carbonate complexes and metal ions and then mixed with cationic polymer to cause the precipitated solids to flocculate. Filtration of the flocculant removes sufficient solids to allow the waste water to be discharged to the surface of a stream. The filtered material is added to the sludge of the concentrated waste stream. The method is also applicable to the treatment and removal of soluble uranium from aqueous streams, such that the treated stream may be used as a potable water supply. 4 figures.

Effects of urbanization on stream water quality in the city of Atlanta, Georgia, USA

USGS Publications Warehouse

Peters, N.E.

2009-01-01

A long-term stream water quality monitoring network was established in the city of Atlanta, Georgia during 2003 to assess baseline water quality conditions and the effects of urbanization on stream water quality. Routine hydrologically based manual stream sampling, including several concurrent manual point and equal width increment sampling, was conducted ???12 times annually at 21 stations, with drainage areas ranging from 3.7 to 232 km2. Eleven of the stations are real-time (RT) stations having continuous measures of stream stage/ discharge, pH, dissolved oxygen, specific conductance, water temperature and turbidity, and automatic samplers for stormwater collection. Samples were analyzed for field parameters, and a broad suite of water quality and sediment-related constituents. Field parameters and concentrations of major ions, metals, nutrient species and coliform bacteria among stations were evaluated and with respect to watershed characteristics and plausible sources from 2003 through September 2007. Most constituent concentrations are much higher than nearby reference streams. Concentrations are statistically different among stations for several constituents, despite high variability both within and among stations. Routine manual sampling, automatic sampling during stormflows and RT water quality monitoring provided sufficient information about urban stream water quality variability to evaluate causes of water quality differences among streams. Fecal coliform bacteria concentrations of most samples exceeded Georgia's water quality standard for any water-usage class. High chloride concentrations occur at three stations and are hypothesized to be associated with discharges of chlorinated combined sewer overflows, drainage of swimming pool(s) and dissolution and transport during rainstorms of CaCl2, a deicing salt applied to roads during winter storms. One stream was affected by dissolution and transport of ammonium alum [NH4Al(SO4)2] from an alum-manufacturing plant; streamwater has low pH (<5), low alkalinity and high metals concentrations. Several trace metals exceed acute and chronic water quality standards and high concentrations are attributed to washoff from impervious surfaces.

Seasonal and event-scale controls on dissolved organic carbon and nitrate flushing from catchments

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Boyer, E. W.; Shanley, J. B.; Doctor, D. H.

2005-05-01

To explore terrestrial and aquatic linkages controlling nutrient dynamics in forested catchments, we collected high-frequency samples from 2002 to 2004 at the Sleepers River Research Watershed in northeastern Vermont USA. We measured DOC (dissolved organic carbon), SUVA (specific UV absorbance), nitrate, and major ion concentrations over a wide range of flow conditions. In addition, weekly samples since 1991 provide a longer term record of stream nutrient fluxes. During events, DOC concentrations increased with flow consistent with the flushing of a large reservoir of mobile organic carbon from forest soils. Higher concentrations of DOC and SUVA in the growing versus dormant season illustrated seasonal variation in sources, characteristics (i.e. reactivity), availability, and controls on the flushing response of organic matter from the landscape to streams. In contrast, stream nitrate concentrations increased with flow but only when catchments "wetted-up" after baseflow periods. Growing season stream nitrate responses were dependent on short-term antecedent moisture conditions indicating rapid depletion of the soil nitrate reservoir when source areas became hydrologically connected to streams. While the different response patterns emphasized variable source and biogeochemical controls in relation to flow patterns, coupled carbon and nitrogen biogeochemical processes were also important controls on stream nutrient fluxes. In particular, leaf fall was a critical time when reactive DOC from freshly decomposing litter fueled in-stream consumption of nitrate leading to sharp declines of stream nitrate concentrations. Our measurements highlight the importance of "hot spots" and "hot moments" of biogeochemical and hydrological processes that control stream responses. Furthermore, our work illustrates how carbon, nitrogen, and water cycles are coupled in catchments, and provides a conceptual model for future work aimed at modeling forest stream hydrochemistry at the catchment scale.

Isotopic variations of dissolved copper and zinc in stream waters affected by historical mining

USGS Publications Warehouse

Borrok, D.M.; Nimick, D.A.; Wanty, R.B.; Ridley, W.I.

2008-01-01

Zinc and Cu play important roles in the biogeochemistry of natural systems, and it is likely that these interactions result in mass-dependent fractionations of their stable isotopes. In this study, we examine the relative abundances of dissolved Zn and Cu isotopes in a variety of stream waters draining six historical mining districts located in the United States and Europe. Our goals were to (1) determine whether streams from different geologic settings have unique or similar Zn and Cu isotopic signatures and (2) to determine whether Zn and Cu isotopic signatures change in response to changes in dissolved metal concentrations over well-defined diel (24-h) cycles. Average ??66Zn and ??65Cu values for streams varied from +0.02??? to +0.46??? and -0.7??? to +1.4???, respectively, demonstrating that Zn and Cu isotopes are heterogeneous among the measured streams. Zinc or Cu isotopic changes were not detected within the resolution of our measurements over diel cycles for most streams. However, diel changes in Zn isotopes were recorded in one stream where the fluctuations of dissolved Zn were the largest. We calculate an apparent separation factor of ???0.3??? (66/64Zn) between the dissolved and solid Zn reservoirs in this stream with the solid taking up the lighter Zn isotope. The preference of the lighter isotope in the solid reservoir may reflect metabolic uptake of Zn by microorganisms. Additional field investigations must evaluate the contributions of soils, rocks, minerals, and anthropogenic components to Cu and Zn isotopic fluxes in natural waters. Moreover, rigorous experimental work is necessary to quantify fractionation factors for the biogeochemical reactions that are likely to impact Cu and Zn isotopes in hydrologic systems. This initial investigation of Cu and Zn isotopes in stream waters suggests that these isotopes may be powerful tools for probing biogeochemical processes in surface waters on a variety of temporal and spatial scales.

Optical sensor for remote estimation of alcohol concentration in blood stream

NASA Astrophysics Data System (ADS)

Shenhav, Asaf; Brodie, Ziv; Beiderman, Yevgeny; Garcia, Javier; Mico, Vicente; Zalevsky, Zeev

2013-02-01

The purpose of this manuscript is to validate our recently developed novel optical approach for extraction of remote vibration sources as a successful technique to estimate the alcohol concentration in blood stream. This technique is based on the tracking of temporal changes of reflected secondary speckle patterns produced in human skin when being illuminated by a laser beam. Since the skin's vibrations profile is changed due to the alcohol in the blood stream, the extraction of the vibration profile can be translated into the corresponding alcohol concentration values by means of defining several parameters acting as indicators for the presence of alcohol in the blood stream. We have conducted several experimental tests showing a good correlation with conventional breath alcohol concentration measurement device when determining alcohol concentration in blood. The presented preliminary results validate the proposed optical sensor as a potentially useful device for measuring alcohol in blood stream with subjects that can be car drivers inspected by police authorities or medically monitored patients.

Occurrence of fecal coliform bacteria in selected streams in Wyoming, 1990-99

USGS Publications Warehouse

Clark, Melanie L.; Norris, Jodi R.

2000-01-01

The U.S. Geological Survey (USGS), in cooperation with the Wyoming Department of Environmental Quality (WDEQ), is collecting water samples for analysis of fecal coliform bacteria at 18 stream sites as part of a statewide network. Contamination by bacteria of fecal origin in streams where contact recreation is a designated water use is a concern because of potential public-health risk from the presence of enteric pathogens. Fecal coliform concentrations are temporally and spatially variable in Wyoming streams-concentrations ranged from less than 1 to 45,000 colonies per 100 milliliters of water during 1990-99. Fecal coliform concentrations were less than the water-quality criterion of 400 colonies per 100 milliliters in 83 percent of the samples, indicating fecal coliform contamination is not a widespread problem in these Wyoming streams. However, 14 of the 18 monitoring sites had at least one sample in which the fecal coliform concentration exceeded 400 colonies per 100 milliliters at some time during the 10-year period. Fecal coliform concentrations generally are higher during April through September than during October through March. The higher concentrations coincide with the time period when the public-health risk is higher because summer months are when contact recreation use is more likely occurring. Fecal coliform concentrations were positively correlated with discharge and stream temperature and generally were negatively correlated with pH, specific conductance, and dissolved oxygen.

Pesticide toxicity index for freshwater aquatic organisms, 2nd edition

USGS Publications Warehouse

Munn, Mark D.; Gilliom, Robert J.; Moran, Patrick W.; Nowell, Lisa H.

2006-01-01

The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with acute toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 124 of the 185 pesticide compounds measured in NAWQA samples, but with a wide range of available bioassays per compound (1 to 232). In the databases examined, there were a total of 3,669 bioassays for the 124 compounds, including 398 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a sublethal response) for freshwater cladocerans, 699 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 2,572 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide, and thus, is based on the concentration addition model of pesticide toxicity. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups. Although the PTI does not determine whether water in a sample is toxic to aquatic organisms, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or additional assessments. The PTI approach may be useful as a basis for comparing the potential significance of pesticides in different streams on a common basis, for evaluating relations between pesticide exposure and observed biological conditions, and for prioritizing where further studies are most needed.

Interactions among irradiance, nutrients, and herbivores constrain a stream algal community.

PubMed

Rosemond, A D

1993-07-01

Using stream-side, flow-through channels, I tested for the effects of nutrients (NU) (nitrogen plus phosphorus), irradiance (L), and snail grazing (G) on a benthic algal community in a small, forested stream. Grazed communities were-dominated by a chlorophyte (basal cells ofStigeoclonium) and a cyanophyte (Chamaesiphon investiens), whereas ungrazed communities were comprised almost entirely of diatoms, regardless of nutrient and light levels. Snails maintained low algal biomass in all grazed treatments, presumably by consuming increased algal production in treatments to which L and NU were increased. When nutrients were increased, cellular nutrient content increased under ambient conditions (shaded, grazed) and biomass and productivity increased when snails were removed and light was increased. Together, nutrients and light had positive effects and grazing had negative effects on biomass (chlorophylla, AFDM, algal biovolume) and chlorophyll-and areal-specific productivity in ANOVAs. However, in most cases, only means from treatments in which all three factors were manipulated (ungrazed, +NU&L treatments) were significantly different from controls; effects of single factors were generally undetectable. These results indicate that all three factors simultaneously limited algal biomass and productivity in this stream during the summer months. Additionally, the effects of these factors in combination were in some cases different from the effects of single factors. For example, light had slight negative effects on some biomass parameters when added at ambient snail densities and nutrient concentrations, but had strong positive effects in conjunction with nutrient addition and snail removal. This study demonstrates that algal biomass and productivity can be under multiple constraints by irradiance, nutrients, and herbivores and indicates the need to employ multifactor experiments to test for such interactive effects.

Aluminum in Precipitation, Streams, and Shallow Groundwater in the New Jersey Pine Barrens

NASA Astrophysics Data System (ADS)

Budd, W. W.; Johnson, A. H.; Huss, J. B.; Turner, R. S.

1981-08-01

Total (acid reactive) aluminum deposited in bulk precipitation in the McDonalds Branch (New Jersey) basin was 140 mg m-2 yr-1 for the period May 1978-May 1980. Stream and groundwater outputs for the same period were 149 and 110 mg m-2 yr-1, respectively. Aluminum inputs and outputs were highest during summer months because of elevated concentrations coupled with increased precipitation and streamflow. Median acid reactive Al concentrations in precipitation, stream water, and groundwater were 100, 350, and 230 μg 1-1, respectively. In streams, acid reactive Al concentration is correlated with dissolved organic matter concentration, suggesting that Al is transported as an organometallic complex. Shallow groundwater Al concentration is apparently controlled by gibbsite solubility in mineral soils and thus is pH dependent. The relatively high Al concentrations are attributable to acid conditions and mobile organic matter.

Water-quality assessment of the eastern Iowa basins : selected pesticides and pesticide degradates in streams, 1996-98

USGS Publications Warehouse

Schnoebelen, Douglas J.; Kalkhoff, Stephen J.; Becher, Kent D.; Thurman, E.M.

2003-01-01

Concentrations of pesticides varied by land-form region. Atrazine and cyanazine and their degradates were present in significantly greater concentrations in streams of the Southern Iowa Drift Plain than streams of either the Des Moines Lobe or the Iowan Surface.

The effect of the runoff size on the pesticide concentration in runoff water and in FOCUS streams simulated by PRZM and TOXSWA.

PubMed

Adriaanse, Paulien I; Van Leerdam, Robert C; Boesten, Jos J T I

2017-04-15

Within the European Union the exposure of aquatic organisms to pesticides is assessed by simulations with the so-called FOCUS Surface Water Scenarios. Runoff plays an important role in these scenarios. As little is known about the effect of runoff size on the exposure, we investigated the effect of runoff size on the concentration in the runoff water and in streams simulated with the PRZM and TOXSWA models for two FOCUS runoff scenarios. For weakly sorbing pesticides (K F,oc <100Lkg -1 ) the pesticide concentration in the runoff water decreased exponentially with increasing daily runoff size. The runoff size hardly affected the pesticide concentration in the runoff water of strongly sorbing pesticides (K F,oc ≥1000Lkg -1 ). For weakly sorbing pesticides the concentration in the FOCUS stream reached a maximum at runoff sizes of about 0.3 to 1mm. The concentration increased rapidly when the runoff size increased from 0 to 0.1mm and gradually decreased when runoff exceeded 1mm. For strongly sorbing pesticides the occurrence of the maximum concentration in the stream is clearly less pronounced and lies approximately between 1 and 20mm runoff. So, this work indicates that preventing small runoff events (e.g. by vegetated buffer strips) reduces exposure concentrations strongly for weakly sorbing pesticides. A simple metamodel was developed for the ratio between the concentrations in the stream and in the runoff water. This model predicted the ratios simulated by TOXSWA very well and it demonstrated that (in addition to runoff size and concentration in runoff) the size of the pesticide-free base flow and pesticide treatment ratio of the catchment determine the stream concentration to a large extent. Copyright © 2016 Elsevier B.V. All rights reserved.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Silver Creek, Clark and Floyd counties, Indiana

USGS Publications Warehouse

Wilber, William G.; Crawford, Charles G.; Peters, James G.

1979-01-01

The Indiana State Board of Health is developing a State water-quality management plan that includes establishing limits for wastewater effluents discharged into Indiana streams. A digital model calibrated to conditions in Silver Creek was used to develop alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. Effluents from the Sellersburg and Clarksville-North wastewater-treatment facilities are the only point-source waste loads that significantly affect the water quality in the modeled segment of Silver Creek. Model simulations indicate that nitrification is the most significant factor affecting the dissolved-oxygen concentration in Silver Creek during summer and winter low flows. Natural streamflow in Silver Creek during the summer and annual 7-day, 10-year low flow is zero, so no benefit from dilution is provided. Present ammonia-nitrogen and dissolved-oxygen concentrations of effluent from the Sellersburg and Clarksville-North wastewater-treatment facilities will violate current Indiana water-quality standards for ammonia toxicity and dissolved oxygen during summer and winter low flows. The current biochemical-oxygen demand limits for the Sellersburg and Clarksville-North wastewater-treatment facilities are not sufficient to maintain an average dissolved-oxygen concentration of at least 5 milligrams per liter, the State 's water-quality standard for streams. Calculations of the stream 's assimilative capacity indicate that Silver Creek cannot assimilate additional waste loadings and meet current Indiana water-quality standards. (Kosco-USGS)

Storm loads of culturable and molecular fecal indicators in an inland urban stream.

PubMed

Liao, Hehuan; Krometis, Leigh-Anne H; Cully Hession, W; Benitez, Romina; Sawyer, Richard; Schaberg, Erin; von Wagoner, Emily; Badgley, Brian D

2015-10-15

Elevated concentrations of fecal indicator bacteria in receiving waters during wet-weather flows are a considerable public health concern that is likely to be exacerbated by future climate change and urbanization. Knowledge of factors driving the fate and transport of fecal indicator bacteria in stormwater is limited, and even less is known about molecular fecal indicators, which may eventually supplant traditional culturable indicators. In this study, concentrations and loading rates of both culturable and molecular fecal indicators were quantified throughout six storm events in an instrumented inland urban stream. While both concentrations and loading rates of each fecal indicator increased rapidly during the rising limb of the storm hydrographs, it is the loading rates rather than instantaneous concentrations that provide a better estimate of transport through the stream during the entire storm. Concentrations of general fecal indicators (both culturable and molecular) correlated most highly with each other during storm events but not with the human-associated HF183 Bacteroides marker. Event loads of general fecal indicators most strongly correlated with total runoff volume, maximum discharge, and maximum turbidity, while event loads of HF183 most strongly correlated with the time to peak flow in a hydrograph. These observations suggest that collection of multiple samples during a storm event is critical for accurate predictions of fecal indicator loading rates and total loads during wet-weather flows, which are required for effective watershed management. In addition, existing predictive models based on general fecal indicators may not be sufficient to predict source-specific genetic markers of fecal contamination. Copyright © 2015 Elsevier B.V. All rights reserved.

Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages.

PubMed

Carpenter, Kurt D; Kuivila, Kathryn M; Hladik, Michelle L; Haluska, Tana; Cole, Michael B

2016-06-01

Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included 33 pesticides, including insecticides, fungicides, herbicides, degradates, and a synergist. Patterns in pesticide occurrence reveal transport of dissolved and sediment-bound pesticides, including pyrethroids, from upland areas through stormwater outfalls to receiving streams. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often for bifenthrin and (or) fipronil. Multiple U.S. EPA benchmark or criterion exceedances occurred in 40 % of urban streams sampled. Bed sediment concentrations of bifenthrin were highly correlated (p < 0.001) with benthic invertebrate assemblages. Non-insects and tolerant invertebrates such as amphipods, flatworms, nematodes, and oligochaetes dominated streams with relatively high concentrations of bifenthrin in bed sediments, whereas insects, sensitive invertebrates, and mayflies were much more abundant at sites with no or low bifenthrin concentrations. The abundance of sensitive invertebrates, % EPT, and select mayfly taxa were strongly negatively correlated with organic-carbon normalized bifenthrin concentrations in streambed sediments. Our findings from western Clackamas County, Oregon (USA), expand upon previous research demonstrating the transport of pesticides from urban landscapes and linking impaired benthic invertebrate assemblages in urban streams with exposure to pyrethroid insecticides.

Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages

USGS Publications Warehouse

Carpenter, Kurt; Kuivila, Kathryn; Hladik, Michelle; Haluska, Tana L.; Michael B. Cole,

2016-01-01

Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included 33 pesticides, including insecticides, fungicides, herbicides, degradates, and a synergist. Patterns in pesticide occurrence reveal transport of dissolved and sediment-bound pesticides, including pyrethroids, from upland areas through stormwater outfalls to receiving streams. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often for bifenthrin and (or) fipronil. Multiple U.S. EPA benchmark or criterion exceedances occurred in 40 % of urban streams sampled. Bed sediment concentrations of bifenthrin were highly correlated (p < 0.001) with benthic invertebrate assemblages. Non-insects and tolerant invertebrates such as amphipods, flatworms, nematodes, and oligochaetes dominated streams with relatively high concentrations of bifenthrin in bed sediments, whereas insects, sensitive invertebrates, and mayflies were much more abundant at sites with no or low bifenthrin concentrations. The abundance of sensitive invertebrates, % EPT, and select mayfly taxa were strongly negatively correlated with organic-carbon normalized bifenthrin concentrations in streambed sediments. Our findings from western Clackamas County, Oregon (USA), expand upon previous research demonstrating the transport of pesticides from urban landscapes and linking impaired benthic invertebrate assemblages in urban streams with exposure to pyrethroid insecticides.

Distribution, speciation, and transport of mercury in stream-sediment, stream-water, and fish collected near abandoned mercury mines in southwestern Alaska, USA

USGS Publications Warehouse

Gray, J.E.; Theodorakos, P.M.; Bailey, E.A.; Turner, R.R.

2000-01-01

Concentrations of total Hg, Hg (II), and methylmercury were measured in stream-sediment, stream-water, and fish collected downstream from abandoned mercury mines in south-western Alaska to evaluate environmental effects to surrounding ecosystems. These mines are found in a broad belt covering several tens of thousands of square kilometers, primarily in the Kuskokwim River basin. Mercury ore is dominantly cinnabar (HgS), but elemental mercury (Hg(o)) is present in ore at one mine and near retorts and in streams at several mine sites. Approximately 1400 t of mercury have been produced from the region, which is approximately 99% of all mercury produced from Alaska. These mines are not presently operating because of low prices and low demand for mercury. Stream-sediment samples collected downstream from the mines contain as much as 5500 ??g/g Hg. Such high Hg concentrations are related to the abundance of cinnabar, which is highly resistant to physical and chemical weathering, and is visible in streams below mine sites. Although total Hg concentrations in the stream-sediment samples collected near mines are high, Hg speciation data indicate that concentrations of Hg (II) are generally less than 5%, and methylmercury concentrations are less than 1% of the total Hg. Stream waters below the mines are neutral to slightly alkaline (pH 6.8-8.4), which is a result of the insolubility of cinnabar and the lack of acid- generating minerals such as pyrite in the deposits. Unfiltered stream-water samples collected below the mines generally contain 500-2500 ng/l Hg; whereas, corresponding stream-water samples filtered through a 0.45-??m membrane contain less than 50 ng/l Hg. These stream-water results indicate that most of the Hg transported downstream from the mines is as finely- suspended material rather than dissolved Hg. Mercury speciation data show that concentrations of Hg (II) and methylmercury in stream-water samples are typically less than 22 ng/l, and generally less than 5% of the total Hg. Muscle samples of fish collected downstream from mines contain as much as 620 ng/g Hg (wet wt.), of which 90-100% is methylmercury. Although these Hg concentrations are several times higher than that in fish collected from regional baseline sites, the concentration of Hg in fish is below the 1000 ng/g action level for edible fish established by the US Food and Drug Administration (FDA). Salmon contain less than 100 ng/g Hg, which are among the lowest Hg contents observed for fish in the study, and well below the FDA action level. (C) 2000 Elsevier Science B.V.

Quantifying stream nutrient uptake from ambient to saturation with instantaneous tracer additions

NASA Astrophysics Data System (ADS)

Covino, T. P.; McGlynn, B. L.; McNamara, R.

2009-12-01

Stream nutrient tracer additions and spiraling metrics are frequently used to quantify stream ecosystem behavior. However, standard approaches limit our understanding of aquatic biogeochemistry. Specifically, the relationship between in-stream nutrient concentration and stream nutrient spiraling has not been characterized. The standard constant rate (steady-state) approach to stream spiraling parameter estimation, either through elevating nutrient concentration or adding isotopically labeled tracers (e.g. 15N), provides little information regarding the stream kinetic curve that represents the uptake-concentration relationship analogous to the Michaelis-Menten curve. These standard approaches provide single or a few data points and often focus on estimating ambient uptake under the conditions at the time of the experiment. Here we outline and demonstrate a new method using instantaneous nutrient additions and dynamic analyses of breakthrough curve (BTC) data to characterize the full relationship between spiraling metrics and nutrient concentration. We compare the results from these dynamic analyses to BTC-integrated, and standard steady-state approaches. Our results indicate good agreement between these three approaches but we highlight the advantages of our dynamic method. Specifically, our new dynamic method provides a cost-effective and efficient approach to: 1) characterize full concentration-spiraling metric curves; 2) estimate ambient spiraling metrics; 3) estimate Michaelis-Menten parameters maximum uptake (Umax) and the half-saturation constant (Km) from developed uptake-concentration kinetic curves, and; 4) measure dynamic nutrient spiraling in larger rivers where steady-state approaches are impractical.

Apparatus for measuring a sorbate dispersed in a fluid stream

NASA Technical Reports Server (NTRS)

Updike, O. L. (Inventor)

1977-01-01

A sensitive, miniature apparatus was designed for measuring low concentrations of a sorbate dispersed in a fluid stream. The device consists of an elongated body having a surface capable of sorbing an amount of the sorbate proportional to the concentration in the fluid stream and propagating acoustic energy along its length. The acoustic energy is converted to an electrical output signal corresponding to the concentration of sorbate in the fluid stream. The device can be designed to exhibit high sensitivity to extremely small amounts of sorbate dispersed in a fluid stream and to exhibit low sensitivity to large amounts of sorbate. Another advantage is that the apparatus may be formed in a microminiature size and at a low cost using bath microfabrication technology.

Relations of biological indicators to nutrient data for lakes and streams in Pennsylvania and West Virginia, 1990-98

USGS Publications Warehouse

Brightbill, Robin A.; Koerkle, Edward H.

2003-01-01

The Clean Water Action Plan of 1998 provides a blueprint for federal agencies to work with states, tribes, and other stakeholders to protect and restore the Nation's water resources. The plan includes an initiative that addresses the nutrient-enrichment problem of lakes and streams across the United States. The U.S. Environmental Protection Agency (USEPA) is working to set nutrient criteria by nationwide nutrient ecoregions that are an aggregation of the Omernik level III ecoregions. Because low levels of nutrients are necessary for healthy streams and elevated concentrations can cause algal blooms that deplete available oxygen and kill off aquatic organisms, criteria levels are to be set, in part, using the relation between chlorophyll a and concentrations of total nitrogen and total phosphorus.Data from Pennsylvania and West Virginia, collected between 1990 and 1998, were analyzed for relations between chlorophyll a, nutrients, and other explanatory variables. Both phytoplankton and periphyton chlorophyll a concentrations from lakes and streams were analyzed separately within each of the USEPA nutrient ecoregions located within the boundaries of the two states. These four nutrient ecoregions are VII (Mostly Glaciated Dairy), VIII (Nutrient Poor, Largely Glaciated Upper Midwest and Northeast), IX (Southeastern Temperate Forested Plains and Hills), and XI (Central and Eastern Forested Uplands).Phytoplankton chlorophyll a concentrations in lakes were related to total nitrogen, total phosphorus, Secchi depth, concentration of dissolved oxygen, pH, water temperature, and specific conductivity. In nutrient ecoregion VII, nutrients were not significant predictors of chlorophyll a concentrations. Total nitrogen, Secchi depth, and pH were significantly related to phytoplankton chlorophyll a concentrations in nutrient ecoregion IX. Lake periphyton chlorophyll a concentrations from nutrient ecoregion XI were related to total phosphorus rather than total nitrogen, Secchi depth, and pH. In all cases, Secchi depth was inversely related to the chlorophyll a concentrations in a lake. Nutrient ecoregion VIII had too few samples for any type of analysis.Streams within the different nutrient ecoregions had many variables that were significantly related to periphyton chlorophyll a concentrations. These variables consisted of total nitrogen, total phosphorus, drainage area, percent forest cover, several macroinvertebrate indices, pH, basin slope, total residue, total suspended solids, and water temperature. Nutrients were not significantly related to periphyton chlorophyll a in streams within nutrient ecoregions VII or IX but were in nutrient ecoregion XI. Drainage area, percent forest cover, and several invertebrate indices were significant variables in nutrient ecoregion VII. Percent forest cover and several invertebrate indices had a negative relation with chlorophyll a concentrations in these streams. Percent forest cover and basin slope had a negative effect on periphyton in nutrient ecoregion IX streams. Light availability was more critical to periphyton growth in streams than nutrients.Ecoregion XI had enough samples to do seasonal analyses. Summer-season periphyton chlorophyll a concentrations in nutrient ecoregion XI streams were positively related to total phosphorus and drainage area but negatively related to percent forest cover. Summer-season phytoplankton in streams was related to different variables within the same nutrient ecoregion. Both total nitrogen and total phosphorus were positively related with chlorophyll a concentrations as well as basin slope, total residue, and total suspended solids but negatively related to pH. The winter stream phytoplankton chlorophyll a concentrations were related to water temperature only.

Methylmercury bioaccumulation in stream food webs declines with increasing primary production

USGS Publications Warehouse

Walters, David; D.F. Raikow,; C.R. Hammerschmidt,; M.G. Mehling,; A. Kovach,; J.T. Oris,

2015-01-01

Opposing hypotheses posit that increasing primary productivity should result in either greater or lesser contaminant accumulation in stream food webs. We conducted an experiment to evaluate primary productivity effects on MeHg accumulation in stream consumers. We varied light for 16 artificial streams creating a productivity gradient (oxygen production =0.048–0.71 mg O2 L–1 d–1) among streams. Two-level food webs were established consisting of phytoplankton/filter feeding clam, periphyton/grazing snail, and leaves/shredding amphipod (Hyalella azteca). Phytoplankton and periphyton biomass, along with MeHg removal from the water column, increased significantly with productivity, but MeHg concentrations in these primary producers declined. Methylmercury concentrations in clams and snails also declined with productivity, and consumer concentrations were strongly correlated with MeHg concentrations in primary producers. Heterotroph biomass on leaves, MeHg in leaves, and MeHg in Hyalella were unrelated to stream productivity. Our results support the hypothesis that contaminant bioaccumulation declines with stream primary production via the mechanism of bloom dilution (MeHg burden per cell decreases in algal blooms), extending patterns of contaminant accumulation documented in lakes to lotic systems.

Comparison of episodic acidification of Mid-Atlantic Upland and Coastal Plain streams

USGS Publications Warehouse

O'Brien, Anne K.; Rice, Karen C.; Kennedy, Margaret M.; Bricker, Owen P.

1993-01-01

Episodic acidification was examined in five mid-Atlantic watersheds representing three physiographic provinces: Coastal Plain, Valley and Ridge, and Blue Ridge. Each of the watersheds receives a similar loading of atmospheric pollutants (SO42− and NO3−) and is underlain by different bedrock type. The purpose of this research was to quantify and compare the episodic variability in storm flow chemistry in Reedy Creek, Virginia (Coastal Plain), Mill Run and Shelter Run, Virginia (Valley and Ridge), and Fishing Creek Tributary and Hunting Creek, Maryland (Blue Ridge). Because episodic responses were similar from storm to storm in each of the watersheds, a representative storm from each watershed was discussed. Acidification, defined as the loss of acid-neutralizing capacity (ANC), was observed in all streams except Mill Run. Mill Run chemistry showed little episodic variability. During storms in the other streams, pH decreased while SO42−, NO3−, and K+ concentrations increased. Concentrations of Mg2+ and Ca2+ increased in Reedy Creek and Fishing Creek Tributary, but decreased in Shelter Run and Hunting Creek. Therefore the net effect of episodic changes on the acid-base status differed among the streams. In general, greater losses of ANC were observed during storms at Shelter Run and Hunting Creek, watersheds underlain by reactive bedrock (carbonate, metabasalt); comparatively smaller losses in ANC were observed at Reedy Creek and Fishing Creek Tributary, watersheds underlain by quartzites and unconsolidated quartz sands and cobbles. Increased SO42− concentrations were most important during storms at Reedy Creek and Fishing Creek Tributary, but organic anions (inferred by anion deficit) were also a factor in causing the loss of ANC. Dilution of base cations was the most important factor in the loss of ANC at Shelter Run. Both increased sulfate and dilution of base flow were important in causing the episodic acidification at Hunting Creek. The role of SO42− in contributing to episodic acidification in these watersheds is similar to that documented in studies conducted in other regions of the United States, Scandinavia, Canada, and the United Kingdom. The importance of SO42− in mid-Atlantic United States streams contrasts with northeastern United States streams, in which increased NO3- derived from snowpack is more important in causing episodic acidification. Results support the importance of shallow subsurface processes in determining storm flow chemistry, regional climatic characteristics in determining the different sources of acidity during episodes, and the importance of bedrock geology in determining the amount of ANC loss.

Sewage treatment method

DOEpatents

Fassbender, Alex G.

1995-01-01

The invention greatly reduces the amount of ammonia in sewage plant effluent. The process of the invention has three main steps. The first step is dewatering without first digesting, thereby producing a first ammonia-containing stream having a low concentration of ammonia, and a second solids-containing stream. The second step is sending the second solids-containing stream through a means for separating the solids from the liquid and producing an aqueous stream containing a high concentration of ammonia. The third step is removal of ammonia from the aqueous stream using a hydrothermal process.

LINKING NUTRIENTS TO ALTERATIONS IN AQUATIC LIFE ...

EPA Pesticide Factsheets

This report estimates the natural background and ambient concentrations of primary producer abundance indicators in California wadeable streams, identifies thresholds of adverse effects of nutrient-stimulated primary producer abundance on benthic macroinvertebrate and algal community structure in CA wadeable streams, and evaluates existing nutrient-algal response models for CA wadeable streams (Tetra Tech 2006), with recommendations for improvements. This information will be included in an assessment of the science forming the basis of recommendations for stream nutrient criteria for the state of California. The objectives of the project are three-fold: 1. Estimate the natural background and ambient concentrations of nutrients and candidate indicators of primary producer abundance in California wadeable streams; 2. Explore relationships and identify thresholds of adverse effects of nutrient concentrations and primary producer abundance on indicators of aquatic life use in California wadeable streams; and 3. Evaluate the Benthic Biomass Spreadsheet Tool (BBST) for California wadeable streams using existing data sets, and recommend avenues for refinement. The intended outcome of this study is NOT final regulatory endpoints for nutrient and response indicators for California wadeable streams.

Episodic acidification of a coastal plain stream in Virginia

USGS Publications Warehouse

O'Brien, A. K.; Eshleman, K.N.

1996-01-01

This study investigates the episodic acidification of Reedy Creek, a wetland-influenced coastal plain stream near Richmond, Virginia. Primary objectives of the study were to quantify the episodic variability of acid- base chemistry in Reedy Creek, to examine the seasonal variability in episodic response and to explain the hydrological and geochemical factors that contribute to episodic acidification. Chemical response was similar in each of the seven storms examined, however, the ranges in concentrations observed were commonly greater in summer/fall storms than in winter/spring storms. An increase in SO4/2- concentration with discharge was observed during all storms and peak concentration occurred at or near peak flow. Small increases in Mg2+, Ca2+, K+ concentrations and dissolved organic carbon (DOC) were observed during most storms. At the same time, ANC, Na+ and Cl- concentrations usually decreased with increasing discharge. In summer/fall storms, the absolute increase in SO4/2- concentration was one-third to 15 times the increase observed in winter/spring storms; the decrease in ANC during summer/fall storms was usually within the range of the decrease observed in winter/spring storms. In contrast, the decrease in Na+ and Cl- concentrations during winter/spring storms was much greater than that observed during summer/fall storms. Data show that while base flow anion deficit was higher in summer/fall than in winter/spring, anion deficit decreased during most summer/fall storms. In contrast, base flow anion deficit was lower in spring and winter, but increased during winter/spring storms. Increased SO4/2- concentration was the main cause of episodic acidification during storms at Reedy Creek, but increased anion deficit indicates organic acids may contribute to episodic acidification during winter/spring storms. Changes in SO4/2- concentration coincident with the hydrograph rise indicate quick routing of water through the watershed. Saturation overland flow appears to be the likely mechanism by which solutes are transported to the stream during storm flow.

Interaction of Strontium-90 in Sediment and Porewater in a Stream Near Chernobyl

NASA Astrophysics Data System (ADS)

Freed, R.; Smith, L.; Bugai, D.

2002-12-01

We investigated the interaction of 90Sr in sediments and pore waters of wetlands and stream hyporheic zones at a stream near Chernobyl. A non-dimensional activity ratio was formulated, the ratio of 90Sr in the pore waters compared with exchangeable 90Sr in the sediment on a volume basis. The average activity ratio for the wetland and channel sediments was 0.028 +/- 0.005. The activity ratio decreased when the sediment and porewaters were not in equilibrium. The change in the activity ratio was documented during two observational periods in a wetland: initially during a time when groundwater was discharging to the wetland (snowmelt, 2000) and subsequently at a time of near-stagnant groundwater flow (late fall in 2001 after a dry three month period). In both the discharge and stagnant periods, the exchangeable 90Sr concentration in sediment increased with depth by a factor of five to a peak concentration at 10 cm. In contrast, the 90Sr concentration in porewater differed significantly in the two observational periods. During the groundwater discharge period, the porewater concentration was relatively constant over the 30 cm depth of observation (120 +/-12 Bq/L) and surface water concentrations were similar. During the near-stagnant period, the porewater concentration increased with depth from 20+/-2 Bq/L in surface waters to 400 +/-40 Bq/L at a depth of 10 cm. We hypothesize that during discharge periods, the porewaters in the wetland represent the 90Sr concentration of advecting groundwater while during stagnant periods, the porewaters represent the concentration of 90Sr in equilibrium with the sediment. This proposed explanation is supported using PHREEQC in a dual porosity mode. Using independent estimates of the model parameters, the concentration profiles could be successfully matched with the assumption of advective transport during the discharge period and diffusive transport of 90Sr during near-stagnant conditions.

Mercury cycling in stream ecosystems. 1. Water column chemistry and transport

USGS Publications Warehouse

Brigham, M.E.; Wentz, D.A.; Aiken, G.R.; Krabbenhoft, D.P.

2009-01-01

We studied total mercury (THg) and methylmercury (MeHg) in eight streams, located in Oregon, Wisconsin, and Florida, that span large ranges in climate, landscape characteristics, atmospheric Hg deposition, and water chemistry. While atmospheric deposition was the source of Hg at each site, basin characteristics appeared to mediate this source by providing controls on methylation and fluvial THg and MeHg transport. Instantaneous concentrations of filtered total mercury (FTHg) and filtered methylmercury (FMeHg) exhibited strong positive correlations with both dissolved organic carbon (DOC) concentrations and streamflow for most streams, whereas mean FTHg and FMeHg concentrations were correlated with wetland density of the basins. For all streams combined, whole water concentrations (sum of filtered and particulate forms) of THg and MeHg correlated strongly with DOC and suspended sediment concentrations in the water column. ?? 2009 American Chemical Society.

Nitrogen transport and transformations in a coastal plain watershed: Influence of geomorphology on flow paths and residence times

USGS Publications Warehouse

Tesoriero, Anthony J.; Spruill, Timothy B.; Mew, H.E.; Farrell, Kathleen M.; Harden, Stephen L.

2005-01-01

Nitrogen transport and groundwater-surface water interactions were examined in a coastal plain watershed in the southeastern United States. Groundwater age dates, calculated using chlorofluorocarbon and tritium concentrations, along with concentrations of nitrogen species and other redox-active constituents, were used to evaluate the fate and transport of nitrate. Nitrate is stable only in recently recharged (<10 years) water found in the upper few meters of saturated thickness in the upland portion of a surficial aquifer. Groundwater with a residence time between 10 and 30 years typically has low nitrate and elevated excess N2 concentrations, indications that denitrification has reduced nitrate concentrations. Groundwater older than 30 years also has low nitrate concentrations but contains little or no excess N2, suggesting that this water did not contain elevated concentrations of nitrate along its flow path. Nitrate transport to streams varies between first- and third-order streams. Hydrologic, lithologic, and chemical data suggest that the surficial aquifer is the dominant source of flow and nitrate to a first-order stream. Iron-reducing conditions occur in groundwater samples from the bed and banks of the first-order stream, suggesting that direct groundwater discharge is denitrified prior to entering the stream. However, nitrogen from the surficial aquifer is transported directly to the stream via a tile drain that bypasses these reduced zones. In the alluvial valley of a third-order stream the erosion of a confining layer creates a much thicker unconfined alluvial aquifer with larger zones of nitrate stability. Age dating and chemical information (SiO 2, Na/K ratios) suggest that water in the alluvial aquifer is derived from short flow paths through the riparian zone and/or from adjacent streams during high-discharge periods. Copyright 2005 by the American Geophysical Union.

Method for enhancing selectivity and recovery in the fractional flotation of particles in a flotation column

DOEpatents

Klunder, Edgar B [Bethel Park, PA

2011-08-09

The method relates to particle separation from a feed stream. The feed stream is injected directly into the froth zone of a vertical flotation column in the presence of a counter-current reflux stream. A froth breaker generates a reflux stream and a concentrate stream, and the reflux stream is injected into the froth zone to mix with the interstitial liquid between bubbles in the froth zone. Counter-current flow between the plurality of bubbles and the interstitial liquid facilitates the attachment of higher hydrophobicity particles to bubble surfaces as lower hydrophobicity particles detach. The height of the feed stream injection and the reflux ratio may be varied in order to optimize the concentrate or tailing stream recoveries desired based on existing operating conditions.

Concentrations of Zn, Mn, Cu and Cd in different tissues of perch (Perca fluviatilis) and in perch intestinal parasite (Acanthocephalus lucii) from the stream near Prague (Czech Republic)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jankovska, Ivana, E-mail: jankovska@af.czu.cz; Miholova, Daniela; Lukesova, Daniela

2012-01-15

We monitored concentrations of Cd, Cu, Mn and Zn in acantocephalan parasites (Acanthocephalus lucii) and its final host (Perca fluviatilis). The concentrations in parasites were found to be significantly higher than those found in the muscle, gonads and liver of fish host. The bioaccumulation factor values were 194, 24.4, 2.2 and 4.7 for Cd, Cu, Mn and Zn, respectively. This suggests a benefit for the host due to the high accumulation of toxic cadmium.

Spectrometer for measuring the concentration of components in a fluid stream and method for using same

DOEpatents

Durham, Michael D.; Stedman, Donald H.; Ebner, Timothy G.; Burkhardt, Mark R.

1991-01-01

A device and method for measuring the concentrations of components of a fluid stream. Preferably, the fluid stream is an in situ gas stream, such as a fossil fuel fired flue gas in a smoke stack. The measurements are determined from the intensity of radiation over a selected range of radiation wavelengths using peak-to-trough calculations. The need for a reference intensity is eliminated.

Agricultural Intensification in the Amazon: Tracking Nitrogen Fertilizer from Soy-Maize Double Cropping to Streams

NASA Astrophysics Data System (ADS)

Cabrera, V. D.; Jankowski, K.; Neill, C.; Macedo, M.; Deegan, L.; Brando, P. M.; Nascimento, S.; Nascimento, E.; Rocha, S.; Coe, M. T.; Nunes, D.

2015-12-01

Globalization and the increasing demand for food create pressure to both expand and intensify agriculture. These changes have potentially large consequences for the solute concentrations and functioning of streams. In the Brazilian Amazon, crop agriculture expanded greatly during the last 20 years. More recently, farmers have intensified production on existing cropland by double cropping of soy and maize during the same year. Maize, a novel crop for the region, requires much higher applications of nitrogen (N) fertilizer than soybeans. To determine whether this novel land use and associated N addition influenced N concentrations in groundwater and stream water, we measured N concentrations in groundwater wells and streams from small headwater watersheds across three land uses (soy-maize, soy, and tropical forest) in the Upper Xingu Basin, a region of rapid cropland intensification in the southern Amazon. Each watershed contained six groundwater wells arranged in a transect reaching cropland field edge on either side of the stream. Total inorganic N concentrations were higher in wells adjacent to fields where double cropping occurred, while stream concentrations did not differ overall among land uses. This suggests the riparian zones are critical in the removal of N, but as the intensification of agriculture continues the ability of the riparian zone to prevent N from traveling to streams is unknown. Their protection is critical to the functioning of tropical watersheds.

Changes in water quality in agricultural catchments after deployment of wastewater treatment plant.

PubMed

Langhammer, Jakub; Rödlová, Sylva

2013-12-01

Insufficient wastewater remediation in small communities and nonpoint source pollution are the key factors in determining the water quality of small streams in an agricultural landscape. Despite the current extensive construction of municipal wastewater treatment facilities in small communities, the level of organic substances and nutrients in the recipient catchments has not decreased in many areas. This paper analyzes the changes in the water quality of the small streams after the deployment of wastewater treatment plants that were designed to address sources of pollution from small municipalities. The analysis is based on the results from a water quality monitoring network in the small watersheds in the Czech Republic. Five rural catchments with one dominant municipal pollution source, where a wastewater treatment plant was deployed during the monitoring period, were selected according to a predefined set of criteria, from a series of 317 profiles. Basic water quality indicators were selected for the assessment: O₂, BOD-5, COD, TOC, conductivity, NH₄-N, NO₂-N, NO₃-N, PT, and PO₄-P. Results of the analysis showed that the simple deployment of the water treatment facilities at these streams often did not lead to a reduction of contamination in the streams. The expected post-deployment changes, namely, a significant and permanent reduction of stream contamination, occurred only in one catchment, whereas in the remainder of the catchments, only marginal changes or even increased concentrations of the contaminants were detected. As the critical factors that determined the efficiency of wastewater treatment were studied, the need for the consideration of the local conditions during the design of the facility, particularly regarding the size of the catchments, initial level of contamination, proper system of operation, and process optimization of the treatment facility, emerged as the important factor.

C-13 dynamics in benthic algae: Effects of light, phosphorus, and biomass development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Walter; Fanta, S.E.; Roberts, Brian J

2008-07-01

We performed three experiments in indoor streams and one experiment in a natural stream to investigate the effects of growth factors on {delta}{sup 13}C levels in benthic microalgae. In the indoor streams, algae grown under conditions of high light and high phosphorus had {delta}{sup 13}C values that were 16% higher than those in algae grown under conditions of low light and low phosphorus. Light effects were much stronger than phosphorus effects. The effects of both factors increased in strength as algal biomass accrued, and by the end of the experiments, algal {delta}{sup 13}C and biomass were highly correlated. In themore » natural stream, algae exposed to direct sunlight were enriched 15% over shaded algae, corroborating the strong effect of light in the indoor streams. Growth factors such as light and nutrients probably reduce discrimination against {delta}{sup 13}C (raising {delta}{sup 13}C values) in benthic microalgae by causing CO{sub 2} depletion both within individual cells and within the assemblage matrix. However, because the most marked fractionation occurred in older and thicker assemblages, CO{sub 2} depletion within the assemblage matrix appeared to be more important than depletion within individual cells. In the absence of carbon-concentrating mechanisms, elevated {delta}{sup 13}C suggests that inorganic carbon may limit the growth of benthic algae. The extensive range of d13C values (-14{per_thousand} to -36{per_thousand}) created by light and nutrient manipulations in this study easily encompassed the mean {delta}{sup 13}C values of both C{sub 3} and C{sub 4} terrestrial plants, indicating the challenge aquatic ecologists face in identifying carbon sources for higher trophic levels when light and nutrient conditions vary.« less

Coupled Effects of Natural and Anthropogenic Controls on Seasonal and Spatial Variations of River Water Quality during Baseflow in a Coastal Watershed of Southeast China

PubMed Central

Huang, Jinliang; Huang, Yaling; Zhang, Zhenyu

2014-01-01

Surface water samples of baseflow were collected from 20 headwater sub-watersheds which were classified into three types of watersheds (natural, urban and agricultural) in the flood, dry and transition seasons during three consecutive years (2010–2012) within a coastal watershed of Southeast China. Integrating spatial statistics with multivariate statistical techniques, river water quality variations and their interactions with natural and anthropogenic controls were examined to identify the causal factors and underlying mechanisms governing spatiotemporal patterns of water quality. Anthropogenic input related to industrial effluents and domestic wastewater, agricultural activities associated with the precipitation-induced surface runoff, and natural weathering process were identified as the potential important factors to drive the seasonal variations in stream water quality for the transition, flood and dry seasons, respectively. All water quality indicators except SRP had the highest mean concentrations in the dry and transition seasons. Anthropogenic activities and watershed characteristics led to the spatial variations in stream water quality in three types of watersheds. Concentrations of NH4 +-N, SRP, K+, CODMn, and Cl− were generally highest in urban watersheds. NO3 –N Concentration was generally highest in agricultural watersheds. Mg2+ concentration in natural watersheds was significantly higher than that in agricultural watersheds. Spatial autocorrelations analysis showed similar levels of water pollution between the neighboring sub-watersheds exhibited in the dry and transition seasons while non-point source pollution contributed to the significant variations in water quality between neighboring sub-watersheds. Spatial regression analysis showed anthropogenic controls played critical roles in variations of water quality in the JRW. Management implications were further discussed for water resource management. This research demonstrates that the coupled effects of natural and anthropogenic controls involved in watershed processes, contribute to the seasonal and spatial variation of headwater stream water quality in a coastal watershed with high spatial variability and intensive anthropogenic activities. PMID:24618771

Observed and modeled seasonal trends in dissolved and particulate Cu, Fe, Mn, and Zn in a mining-impacted stream.

PubMed

Butler, Barbara A; Ranville, James F; Ross, Philippe E

2008-06-01

North Fork Clear Creek (NFCC) in Colorado, an acid-mine drainage (AMD) impacted stream, was chosen to examine the distribution of dissolved and particulate Cu, Fe, Mn, and Zn in the water column, with respect to seasonal hydrologic controls. NFCC is a high-gradient stream with discharge directly related to snowmelt and strong seasonal storms. Additionally, conditions in the stream cause rapid precipitation of large amounts of hydrous iron oxides (HFO) that sequester metals. Because AMD-impacted systems are complex, geochemical modeling may assist with predictions and/or confirmations of processes occurring in these environments. This research used Visual-MINTEQ to determine if field data collected over a two and one-half year study would be well represented by modeling with a currently existing model, while limiting the number of processes modeled and without modifications to the existing model's parameters. Observed distributions between dissolved and particulate phases in the water column varied greatly among the metals, with average dissolved fractions being >90% for Mn, approximately 75% for Zn, approximately 30% for Cu, and <10% for Fe. A strong seasonal trend was observed for the metals predominantly in the dissolved phase (Mn and Zn), with increasing concentrations during base-flow conditions and decreasing concentrations during spring-runoff. This trend was less obvious for Cu and Fe. Within hydrologic seasons, storm events significantly influenced in-stream metals concentrations. The most simplified modeling, using solely sorption to HFO, gave predicted percentage particulate Cu results for most samples to within a factor of two of the measured values, but modeling data were biased toward over-prediction. About one-half of the percentage particulate Zn data comparisons fell within a factor of two, with the remaining data being under-predicted. Slightly more complex modeling, which included dissolved organic carbon (DOC) as a solution phase ligand, significantly reduced the positive bias between observed and predicted percentage particulate Cu, while inclusion of hydrous manganese oxide (HMO) yielded model results more representative of the observed percentage particulate Zn. These results indicate that there is validity in the use of an existing model, without alteration and with typically collected water chemistry data, to describe complex natural systems, but that processes considered optimal for one metal might not be applicable for all metals in a given water sample.

METHOD OF CENTRIFUGE OPERATION

DOEpatents

Cohen, K.

1960-05-10

A method of isotope separation is described in which two streams are flowed axially of, and countercurrently through, a cylindrical centrifuge bowl. Under the influence of a centrifugal field, the light fraction is concentrated in a stream flowing through the central portion of the bowl, whereas the heavy fraction is concentrated in a stream at the periphery thereof.

RELATIONS BETWEEN LAND USE AND STREAM NUTRIENT CONCENTRATIONS FOR SMALL WATERSHEDS IN THE GEORGIA PIEDMONT

EPA Science Inventory

We have been sampling nutrient concentrations in 17 headwater streams within the South Fork Broad River (SFBR) watershed on a monthly basis since November 2001. The streams were classified as either developed (n=4), agriculture/pasture (n=4), mixed land use (n=6) or forested (n=3...

Research Paper. Nutrient uptake and mineralization during leaf decay in streams-a model simulation.

Treesearch

J.R. Webster; J.D. Newbold; S.A. Thomas; H.M. Valett; P.J. Mulholland

2009-01-01

We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of...

Discharge process of cesium during rainstorms in headwater catchments, Fukushima, Japan

NASA Astrophysics Data System (ADS)

Tsujimura, Maki; Onda, Yuichi; Iwagami, Sho; Nishino, Masataka; Konuma, Ryohei

2014-05-01

We monitored Cs-137 concentrations in stream water, groundwater, soil water and rainwater in the Yamakiya district located approximately 35 km north west of Fukushima Dai-ichi Nuclear Power Plant (FDNPP) from June 2011 through July 2013, focusing on rainfall-runoff processes during the rainstorm events. Two catchments with different land cover (Iboishiyama and Koutaishiyama) were instrumentd, and stream water, groundwater, soil water and rainwater were sampled for approximately one month at each site, and intensive sampling was conducted during rainstorm events. The 137Cs concentration in stream water showed a relatively quick decreasing trend during 2011. Also, during rainfall events, the Cs-137 concentration in stream water showed a temporary increase. End Member Mixing Analysis was applied to evaluate contribution of groundwater, soil water and rainwater in discharge water during rainstorm events. The groundwater component was dominant in the runoff, whereas rainwater was main source for the Cs-137 concentration of the stream increasing during the storm events. In addition, a leaching of Cs-137 from the suspended sediments and the organic materials seemed to be also important sources to the stream.

Atrazine concentrations in stream water and streambed sediment pore water in the St. Joseph and Galien River basins, Michigan and Indiana, May 2001-September 2003

USGS Publications Warehouse

Duris, Joseph W.; Reeves, Howard W.; Kiesler, James L.

2005-01-01

The U.S. Geological Survey (USGS) sampled multiple stream sites across the St. Joseph and Galien River Basins to detect and quantify the herbicide atrazine using a field enzyme-linked immunosorbent assay (ELISA) triazine test. In May 2001, July 2001, April 2002, August 2002, August 2003 and September 2003, composite samples were collected across streams at USGS streamflow-gaging stations. Concentrations and instantaneous loading for atrazine sampled in stream water throughout the St. Joseph River and Galien River Basins in Michigan and Indiana ranged from nondetection (< 0.05 part per billion (ppb)) with an associated load less than 0.001 kilogram per day (kg/d) to 6 ppb and a maximum load of 10 kg/d. Atrazine concentrations were highest in May 2001 just after the planting season. The lowest concentration was found in April 2002 just before planting. Atrazine concentrations in streambed-sediment pore water were not spatially connected with atrazine concentrations in stream-water samples. This study showed that atrazine concentrations were elevated from May to July in the St. Joseph and Galien River Basins. At many sites, concentrations exceeded the level that has been shown to feminize frog populations (0.2 ppb). There were 8 sites where concentrations exceeded 0.2 ppb atrazine in May 2001 and July 2001.

Wastewater effluent, combined sewer overflows, and other sources of organic compounds to Lake Champlain

USGS Publications Warehouse

Phillips, P.; Chalmers, A.

2009-01-01

Some sources of organic wastewater compounds (OWCs) to streams, lakes, and estuaries, including wastewater-treatment-plant effluent, have been well documented, but other sources, particularly wet-weather discharges from combined-sewer-overflow (CSO) and urban runoff, may also be major sources of OWCs. Samples of wastewater-treatment-plant (WWTP) effluent, CSO effluent, urban streams, large rivers, a reference (undeveloped) stream, and Lake Champlain were collected from March to August 2006. The highest concentrations of many OWCs associated with wastewater were in WWTP-effluent samples, but high concentrations of some OWCs in samples of CSO effluent and storm runoff from urban streams subject to leaky sewer pipes or CSOs were also detected. Total concentrations and numbers of compounds detected differed substantially among sampling sites. The highest total OWC concentrations (10-100 ??g/l) were in samples of WWTP and CSO effluent. Total OWC concentrations in samples from urban streams ranged from 0.1 to 10 ??g/l, and urban stream-stormflow samples had higher concentrations than baseflow samples because of contributions of OWCs from CSOs and leaking sewer pipes. The relations between OWC concentrations in WWTP-effluent and those in CSO effluent and urban streams varied with the degree to which the compound is removed through normal wastewater treatment. Concentrations of compounds that are highly removed during normal wastewater treatment [including caffeine, Tris(2-butoxyethyl)phosphate, and cholesterol] were generally similar to or higher in CSO effluent than in WWTP effluent (and ranged from around 1 to over 10 ??g/l) because CSO effluent is untreated, and were higher in urban-stream stormflow samples than in baseflow samples as a result of CSO discharge and leakage from near-surface sources during storms. Concentrations of compounds that are poorly removed during treatment, by contrast, are higher in WWTP effluent than in CSO, due to dilution. Results indicate that CSO effluent and urban stormwaters can be a significant major source of OWCs entering large water bodies such as Burlington Bay. ?? 2008 American Water Resources Association.

Concentrations of selected pharmaceuticals and antibiotics in south-central Pennsylvania waters, March through September 2006

USGS Publications Warehouse

Loper, Connie A.; Crawford, J. Kent; Otto, Kim L.; Manning, Rhonda L.; Meyer, Michael T.; Furlong, Edward T.

2007-01-01

This report presents environmental and quality-control data from analyses of 15 pharmaceutical and 31 antibiotic compounds in water samples from streams and wells in south-central Pennsylvania. The analyses are part of a study by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Environmental Protection (PADEP) to define concentrations of selected emerging contaminants in streams and well water in Pennsylvania. Sampling was conducted at 11 stream sites and at 6 wells in 9 counties of south-central Pennsylvania. Five of the streams received municipal wastewater and 6 of the streams received runoff from agricultural areas dominated by animal-feeding operations. For all 11 streams, samples were collected at locations upstream and downstream of the municipal effluents or animal-feeding operations. All six wells were in agricultural settings. A total of 120 environmental samples and 21 quality-control samples were analyzed for the study. Samples were collected at each site in March/April, May, July, and September 2006 to obtain information on changes in concentration that could be related to seasonal use of compounds.For streams, 13 pharmaceuticals and 11 antibiotics were detected at least 1 time. Detections included analytical results that were estimated or above the minimum reporting limits. Seventy-eight percent of all detections were analyzed in samples collected downstream from municipal-wastewater effluents. For streams receiving wastewater effluents, the pharmaceuticals caffeine and para-xanthine (a degradation product of caffeine) had the greatest concentrations, 4.75 μg/L (micrograms per liter) and 0.853 μg/L, respectively. Other pharmaceuticals and their respective maximum concentrations were carbamazepine (0.516 μg/L) and ibuprofen (0.277 μg/L). For streams receiving wastewater effluents, the antibiotic azithromycin had the greatest concentration (1.65 μg/L), followed by sulfamethoxazole (1.34 μg/L), ofloxacin (0.329 μg/L), and trimethoprim (0.256 μg/L).For streams receiving runoff from animal-feeding operations, the only pharmaceuticals detected were acetaminophen, caffeine, cotinine, diphenhydramine, and carbamazepine. The maximum concentration for pharmaceuticals was 0.053 μg/L. Three streams receiving runoff from animal-feeding operations had detections of one or more antibiotic compound--oxytetracycline, sulfadimethoxine, sulfamethoxazole, and tylosin. The maximum concentration for antibiotics was 0.157 μg/L. The average number of compounds (pharmaceuticals and antibiotics) detected in sites downstream from animal-feeding operations was three. The average number of compounds detected downstream from municipal-wastewater effluents was 13.For wells used to supply livestock, four compounds were detected--two pharmaceuticals (cotinine and diphenhydramine) and two antibiotics (tylosin and sulfamethoxazole). There were five detections in all the well samples. The maximum concentration detected in well water was for cotinine, estimated to be 0.024 μg/L.Seasonal occurrence of pharmaceutical and antibiotic compounds in stream water varied by compound and site type. At four stream sites, the same compounds were detected in all four seasonal samples. At other sites, pharmaceutical or antibiotic compounds were detected only one time in seasonal samples. Winter samples collected in streams receiving municipalwastewater effluent had the greatest number of compounds detected (21). Research analytical methods were used to determine concentrations for pharmaceuticals and antibiotics. To assist in evaluating the quality of the analyses, detailed information is presented on laboratory methodology and results from qualitycontrol samples. Quality-control data include results for nine blanks, nine duplicate environmental sample pairs, and three laboratory-spiked environmental samples as well as the recoveries of compounds in laboratory surrogates and laboratory reagent spikes.

Heavy metal pollution associated with an abandoned lead-zinc mine in the Kirki region, NE Greece.

PubMed

Nikolaidis, Christos; Zafiriadis, Ilias; Mathioudakis, Vasileios; Constantinidis, Theodore

2010-09-01

The "Agios Philippos" mine in the Kirki region (NE Greece) has been abandoned in 1998 after half a century of ore exploration without a reclamation or remediation plan. This article aims at elucidating the potential environmental risks associated with this site by quantifying pollution in tailing basins, stream waters, stream sediments and agricultural fields. Concentrations of heavy metals in the abandoned mine tailings reached 12,567 mg/kg for Pb, 22,292 mg/kg for Zn, 174 mg/kg for Cd and 241 mg/kg for As. The geoaccumulation index and enrichment factor for these metals were indicative of extremely high contamination (I(geo) > 5) and extremely high enrichment (EF > 40), respectively. Stream waters in the proximity of the mine had an acidic pH equal to 5.96 and a high sulfate content (SO(4)(-2) = 545.5 mg/L), whereas concentrations of Mn, Zn and Cd reached 2,399 microg/L, 7,681 microg/L and 11.2 microg/L. High I(geo) and EF values for Cd, Zn and As in stream sediments indicates that surface water pollution has a historic background, which is typically associated with acid mine drainage. Agricultural fields in the proximity of the mine exhibited high I(geo) and EF values, which were in decreasing order Cd > Pb > Zn > As. These findings urge for an immediate remediation action of the afflicted area.

Changes in the character of DOC in streams during storms in two Midwestern watersheds with contrasting land uses

USGS Publications Warehouse

Vidon, P.; Wagner, L.E.; Soyeux, E.

2008-01-01

Dissolved organic carbon (DOC) dynamics in streams is important, yet few studies focus on DOC dynamics in Midwestern streams during storms. In this study, stream DOC dynamics during storms in two Midwestern watersheds with contrasting land uses, the change in character of stream DOC during storms, and the usability of DOC as a hydrologic tracer in artificially drained landscapes of the Midwest are investigated. Major cation/DOC concentrations, and DOC specific UV absorbance (SUVA) and fluorescence index (FI) were monitored at 2-4 h intervals during three spring storms. Although DOC is less aromatic in the mixed land use watershed than in the agricultural watershed, land use has little impact on stream DOC concentration during storms. For both watersheds, DOC concentration follows discharge, and SUVA and FI values indicate an increase in stream DOC aromaticity and lignin content during storms. The comparison of DOC/major cation flushing dynamics indicates that DOC is mainly exported via overland flow/macropore flow. In both watersheds, the increase in DOC concentration in the streams during storms corresponds to a shift in the source of DOC from DOC originating from mineral soil layers of the soil profile at baseflow, to DOC originating from surficial soil layers richer in aromatic substances and lignin during storms. Results also suggest that DOC, SUVA and FI could be used as hydrologic tracers in artificially drained landscapes of the Midwest. These results underscore the importance of sampling streams for DOC during high flow periods in order to understand the fate of DOC in streams. ?? 2008 Springer Science+Business Media B.V.

Effects of Atmospheric Nitrate on an Upland Stream of the Northeastern USA

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Kendall, C.

2009-05-01

Excess nitrogen cascades through terrestrial biogeochemical cycles and affects stream nitrate concentrations in upland forests where atmospheric deposition is an important source of anthropogenic nitrogen. We will discuss approaches including high-frequency sampling, isotopic tracers, and end-member mixing analysis that can be used to decipher the sources, transformations, and hydrological processes that affect nitrate transport through forested upland catchments to streams. We present results of studies at the Sleepers River Research Watershed in Vermont, USA, a site where we have intensively measured stream nitrate concentrations during baseflow and stormflow. Stream nitrate concentrations are typically low and nearly 75% of annual inorganic N inputs from atmospheric deposition are retained within the catchment. However, high concentrations and stream loadings of nitrate occur during storm events due to source variation and hydrological flushing of nitrate from catchment soils. Using isotopic tracers and end-member mixing analysis, we have quantified source inputs of unprocessed atmospheric nitrate and show that this stream is directly affected by nitrogen pollution. Using a long-term record of stream hydrochemistry and our findings on event- scale nitrate flushing dynamics, we then explore how stream nitrate loading may respond to anthropogenic climate forcing during the next century. Results suggest that stream runoff and nitrate loadings will change during future emission scenarios (i.e. longer growing seasons and higher winter precipitation rates). Understanding the timing and magnitude of hydrological and hydrochemical responses is important because climate change effects on catchment hydrology may alter how nitrate is retained, produced, and hydrologically flushed in headwater ecosystems with implications for aquatic metabolism, nutrient export from catchments, and downstream eutrophication.

Large-scale variation in subsurface stream biofilms: a cross-regional comparison of metabolic function and community similarity.

PubMed

Findlay, S; Sinsabaugh, R L

2006-10-01

We examined bacterial metabolic activity and community similarity in shallow subsurface stream sediments distributed across three regions of the eastern United States to assess whether there were parallel changes in functional and structural attributes at this large scale. Bacterial growth, oxygen consumption, and a suite of extracellular enzyme activities were assayed to describe functional variability. Community similarity was assessed using randomly amplified polymorphic DNA (RAPD) patterns. There were significant differences in streamwater chemistry, metabolic activity, and bacterial growth among regions with, for instance, twofold higher bacterial production in streams near Baltimore, MD, compared to Hubbard Brook, NH. Five of eight extracellular enzymes showed significant differences among regions. Cluster analyses of individual streams by metabolic variables showed clear groups with significant differences in representation of sites from different regions among groups. Clustering of sites based on randomly amplified polymorphic DNA banding resulted in groups with generally less internal similarity although there were still differences in distribution of regional sites. There was a marginally significant (p = 0.09) association between patterns based on functional and structural variables. There were statistically significant but weak (r2 approximately 30%) associations between landcover and measures of both structure and function. These patterns imply a large-scale organization of biofilm communities and this structure may be imposed by factor(s) such as landcover and covariates such as nutrient concentrations, which are known to also cause differences in macrobiota of stream ecosystems.

Relations of benthic macroinvertebrates to concentrations of trace elements in water, streambed sediments, and transplanted bryophytes and stream habitat conditions in nonmining and mining areas of the upper Colorado River basin, Colorado, 1995-98

USGS Publications Warehouse

Mize, Scott V.; Deacon, Jeffrey R.

2002-01-01

Intensive mining activity and highly mineralized rock formations have had significant impacts on surface-water and streambed-sediment quality and aquatic life within the upper reaches of the Uncompahgre River in western Colorado. A synoptic study by the U.S. Geological Survey National Water-Quality Assessment Program was completed in the upper Uncompahgre River Basin in 1998 to better understand the relations of trace elements (with emphasis on aluminum, arsenic, copper, iron, lead, and zinc concentrations) in water, streambed sediment, and aquatic life. Water-chemistry, streambed-sediment, and benthic macroinvertebrate samples were collected during low-flow conditions between October 1995 and July 1998 at five sites on the upper Uncompahgre River, all downstream from historical mining, and at three sites in drainage basins of the Upper Colorado River where mining has not occurred. Aquatic bryophytes were transplanted to all sites for 15 days of exposure to the water column during which time field parameters were measured and chemical water-quality and benthic macroinvertebrate samples were collected. Stream habitat characteristics also were documented at each site. Certain attributes of surface-water chemistry among streams were significantly different. Concentrations of total aluminum, copper, iron, lead, and zinc in the water column and concentrations of dissolved aluminum, copper, and zinc were significantly different between nonmining and mining sites. Some sites associated with mining exceeded Colorado acute aquatic-life standards for aluminum, copper, and zinc and exceeded Colorado chronic aquatic-life standards for aluminum, copper, iron, lead, and zinc. Concentrations of copper, lead, and zinc in streambed sediments were significantly different between nonmining and mining sites. Generally, concentrations of arsenic, copper, lead, and zinc in streambed sediments at mining sites exceeded the Canadian Sediment Quality Guidelines probable effect level (PEL), except at two mining sites where concentrations of copper and zinc were below the PEL. Concentrations of arsenic, copper, iron, and lead in transplanted bryophytes were significantly different between nonmining and mining sites. Bioconcentration factors calculated for 15-day exposure using one-half of the minimum reporting level were significantly different between nonmining and mining sites. In general, concentrations of trace elements in streambed sediment and transplanted bryophytes were more closely correlated than were the concentrations of trace elements in the water column with streambed sediments or concentrations in the water column with transplanted bryophytes. Stream habitat was rated as optimal to suboptimal using the U.S. Environmental Protection Agency Rapid Bioassessment Protocols for all sites in the study area. Generally, stream habitat conditions were similar at nonmining compared to mining sites and were suitable for diverse macroinvertebrate communities. All study sites had optimal instream habitat except two mining sites with suboptimal instream habitat because of disturbances in stream habitat. The benthic macroinvertebrate community composition at nonmining sites and mining sites differed. Mining sites had significantly lower total abundance of macroinvertebrates, fewer numbers of taxa, and lower dominance of Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies), and a larger percentage of tolerant species than did nonmining sites. The predominance of Baetis sp. (mayflies), Hydropsychidae (caddisflies), and large percentage of Orthocladiinae chironomids (midges) at mining sites indicated that these species may be tolerant to elevated trace-element concentrations. The absence of Heptageniidae (mayflies), Chloroperlidae (stoneflies), and Rhyacophila sp. (caddisflies) at mining sites indicated that these species may be sensitive to elevated trace-element concentrations. Comparison of field parameters and

Mercury cycling in stream ecosystems. 2. Benthic methylmercury production and bed sediment-pore water partitioning.

PubMed

Marvin-Dipasquale, Mark; Lutz, Michelle A; Brigham, Mark E; Krabbenhoft, David P; Aiken, George R; Orem, William H; Hall, Britt D

2009-04-15

Mercury speciation, controls on methylmercury (MeHg) production, and bed sediment-pore water partitioning of total Hg (THg) and MeHg were examined in bed sediment from eight geochemically diverse streams where atmospheric deposition was the predominant Hg input. Across all streams, sediment THg concentrations were best described as a combined function of sediment percent fines (%fines; particles < 63 microm) and organic content. MeHg concentrations were best described as a combined function of organic content and the activity of the Hg(II)-methylating microbial community and were comparable to MeHg concentrations in streams with Hg inputs from industrial and mining sources. Whole sediment tin-reducible inorganic reactive Hg (Hg(II)R) was used as a proxy measure for the Hg(II) pool available for microbial methylation. In conjunction with radiotracer-derived rate constants of 203Hg(II) methylation, Hg(II)R was used to calculate MeHg production potential rates and to explain the spatial variability in MeHg concentration. The %Hg(II)R (of THg) was low (2.1 +/- 5.7%) and was inversely related to both microbial sulfate reduction rates and sediment total reduced sulfur concentration. While sediment THg concentrations were higher in urban streams, %MeHg and %Hg(II)R were higher in nonurban streams. Sediment pore water distribution coefficients (log Kd's) for both THg and MeHg were inversely related to the log-transformed ratio of pore water dissolved organic carbon (DOC) to bed sediment %fines. The stream with the highest drainage basin wetland density also had the highest pore water DOC concentration and the lowest log Kd's for both THg and MeHg. No significant relationship existed between overlying water MeHg concentrations and those in bed sediment or pore water, suggesting upstream sources of MeHg production may be more important than local streambed production as a driver of water column MeHg concentration in drainage basins that receive Hg inputs primarily from atmospheric sources.

Estimation of time-variable fast flow path chemical concentrations for application in tracer-based hydrograph separation analyses

USGS Publications Warehouse

Kronholm, Scott C.; Capel, Paul D.

2016-01-01

Mixing models are a commonly used method for hydrograph separation, but can be hindered by the subjective choice of the end-member tracer concentrations. This work tests a new variant of mixing model that uses high-frequency measures of two tracers and streamflow to separate total streamflow into water from slowflow and fastflow sources. The ratio between the concentrations of the two tracers is used to create a time-variable estimate of the concentration of each tracer in the fastflow end-member. Multiple synthetic data sets, and data from two hydrologically diverse streams, are used to test the performance and limitations of the new model (two-tracer ratio-based mixing model: TRaMM). When applied to the synthetic streams under many different scenarios, the TRaMM produces results that were reasonable approximations of the actual values of fastflow discharge (±0.1% of maximum fastflow) and fastflow tracer concentrations (±9.5% and ±16% of maximum fastflow nitrate concentration and specific conductance, respectively). With real stream data, the TRaMM produces high-frequency estimates of slowflow and fastflow discharge that align with expectations for each stream based on their respective hydrologic settings. The use of two tracers with the TRaMM provides an innovative and objective approach for estimating high-frequency fastflow concentrations and contributions of fastflow water to the stream. This provides useful information for tracking chemical movement to streams and allows for better selection and implementation of water quality management strategies.

The role of hydrodynamics in shaping the composition and architecture of epilithic biofilms in fluvial ecosystems.

PubMed

Risse-Buhl, Ute; Anlanger, Christine; Kalla, Katalin; Neu, Thomas R; Noss, Christian; Lorke, Andreas; Weitere, Markus

2017-12-15

Previous laboratory and on-site experiments have highlighted the importance of hydrodynamics in shaping biofilm composition and architecture. In how far responses to hydrodynamics can be found in natural flows under the complex interplay of environmental factors is still unknown. In this study we investigated the effect of near streambed turbulence in terms of turbulent kinetic energy (TKE) on the composition and architecture of biofilms matured in two mountainous streams differing in dissolved nutrient concentrations. Over both streams, TKE significantly explained 7% and 8% of the variability in biofilm composition and architecture, respectively. However, effects were more pronounced in the nutrient richer stream, where TKE significantly explained 12% and 3% of the variability in biofilm composition and architecture, respectively. While at lower nutrient concentrations seasonally varying factors such as stoichiometry of dissolved nutrients (N/P ratio) and light were more important and explained 41% and 6% of the variability in biofilm composition and architecture, respectively. Specific biofilm features such as elongated ripples and streamers, which were observed in response to the uniform and unidirectional flow in experimental settings, were not observed. Microbial biovolume and surface area covered by the biofilm canopy increased with TKE, while biofilm thickness and porosity where not affected or decreased. These findings indicate that under natural flows where near bed flow velocities and turbulence intensities fluctuate with time and space, biofilms became more compact. They spread uniformly on the mineral surface as a film of densely packed coccoid cells appearing like cobblestone pavement. The compact growth of biofilms seemed to be advantageous for resisting hydrodynamic shear forces in order to avoid displacement. Thus, near streambed turbulence can be considered as important factor shaping the composition and architecture of biofilms grown under natural flows. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams.

PubMed

Ciparis, Serena; Iwanowicz, Luke R; Voshell, J Reese

2012-01-01

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO(4)-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1 ng/L. Relatively high concentrations of DIN (>1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R(2) = 0.56-0.81) and E2Eq (R(2) = 0.39-0.75). Relationships between watershed densities of AFOs and PO(4)-P were weaker, but were also significant (R(2) = 0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO(4)-P than streams without WWTP discharges, and PO(4)-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. Copyright © 2011 Elsevier B.V. All rights reserved.

Flushing of distal hillslopes as an alternative source of stream dissolved organic carbon in a headwater catchment

USGS Publications Warehouse

Gannon, John P; Bailey, Scott W.; McGuire, Kevin J.; Shanley, James B.

2015-01-01

We investigated potential source areas of dissolved organic carbon (DOC) in headwater streams by examining DOC concentrations in lysimeter, shallow well, and stream water samples from a reference catchment at the Hubbard Brook Experimental Forest. These observations were then compared to high-frequency temporal variations in fluorescent dissolved organic matter (FDOM) at the catchment outlet and the predicted spatial extent of shallow groundwater in soils throughout the catchment. While near-stream soils are generally considered a DOC source in forested catchments, DOC concentrations in near-stream groundwater were low (mean = 2.4 mg/L, standard error = 0.6 mg/L), less than hillslope groundwater farther from the channel (mean = 5.7 mg/L, standard error = 0.4 mg/L). Furthermore, water tables in near-stream soils did not rise into the carbon-rich upper B or O horizons even during events. In contrast, soils below bedrock outcrops near channel heads where lateral soil formation processes dominate had much higher DOC concentrations. Soils immediately downslope of bedrock areas had thick eluvial horizons indicative of leaching of organic materials, Fe, and Al and had similarly high DOC concentrations in groundwater (mean = 14.5 mg/L, standard error = 0.8 mg/L). Flow from bedrock outcrops partially covered by organic soil horizons produced the highest groundwater DOC concentrations (mean = 20.0 mg/L, standard error = 4.6 mg/L) measured in the catchment. Correspondingly, stream water in channel heads sourced in part by shallow soils and bedrock outcrops had the highest stream DOC concentrations measured in the catchment. Variation in FDOM concentrations at the catchment outlet followed water table fluctuations in shallow to bedrock soils near channel heads. We show that shallow hillslope soils receiving runoff from organic matter-covered bedrock outcrops may be a major source of DOC in headwater catchments in forested mountainous regions where catchments have exposed or shallow bedrock near channel heads.

Spectrometer for measuring the concentration of components in a fluid stream and method for using same

DOEpatents

Durham, M.D.; Stedman, D.H.; Ebner, T.G.; Burkhardt, M.R.

1991-12-03

A device and method are described for measuring the concentrations of components of a fluid stream. Preferably, the fluid stream is an in-situ gas stream, such as a fossil fuel fired flue gas in a smoke stack. The measurements are determined from the intensity of radiation over a selected range of radiation wavelengths using peak-to-trough calculations. The need for a reference intensity is eliminated. 15 figures.

What if the Hubbard Brook weirs had been built somewhere else? Spatial uncertainty in the application of catchment budgets

NASA Astrophysics Data System (ADS)

Bailey, S. W.

2016-12-01

Nine catchments are gaged at Hubbard Brook Experimental Forest, Woodstock, NH, USA, with weirs installed on adjacent first-order streams. These catchments have been used as unit ecosystems for analysis of chemical budgets, including evaluation of long term trends and response to disturbance. This study examines uncertainty in the representativeness of these budgets to other nearby catchments, or as representatives of the broader northern hardwood ecosystem, depending on choice of location of the stream gaging station. Within forested northern hardwood catchments across the Hubbard Brook region, there is relatively little spatial variation in amount or chemistry of precipitation inputs or in amount of streamwater outputs. For example, runoff per unit catchment area varies by less than 10% at gaging stations on first to sixth order streams. In contrast, concentrations of major solutes vary by an order of magnitude or more across stream sampling sites, with a similar range in concentrations seen within individual first order catchments as seen across the third order Hubbard Brook valley or across the White Mountain region. These spatial variations in stream chemistry are temporally persistent across a range of flow conditions. Thus first order catchment budgets vary greatly depending on very local variations in stream chemistry driven by choice of the site to develop a stream gage. For example, carbon output in dissolved organic matter varies by a factor of five depending on where the catchment output is defined at Watershed 3. I hypothesize that catchment outputs from first order streams are driven by spatially variable chemistry of shallow groundwater, reflecting local variations in the distribution of soils and vegetation. In contrast, spatial variability in stream chemistry decreases with stream order, hypothesized to reflect deeper groundwater inputs on larger streams, which are more regionally uniform. Thus, choice of a gaging site and definition of an ecosystem as a unit of analysis at a larger scale, such as the Hubbard Brook valley, would have less impact on calculated budgets than at the headwater scale. Monitoring of a larger catchment is more likely to be representative of other similar sized catchments. However, particular research questions may be better studied at the smaller headwater scale.

Development And Initial Testing Of Off-Gas Recycle Liquid From The WTP Low Activity Waste Vitrification Process - 14333

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCabe, Daniel J.; Wilmarth, William R.; Nash, Charles A.

2014-01-07

The Waste Treatment and Immobilization Plant (WTP) process flow was designed to pre-treat feed from the Hanford tank farms, separate it into a High Level Waste (HLW) and Low Activity Waste (LAW) fraction and vitrify each fraction in separate facilities. Vitrification of the waste generates an aqueous condensate stream from the off-gas processes. This stream originates from two off-gas treatment unit operations, the Submerged Bed Scrubber (SBS) and the Wet Electrospray Precipitator (WESP). Currently, the baseline plan for disposition of the stream from the LAW melter is to recycle it to the Pretreatment facility where it gets evaporated and processedmore » into the LAW melter again. If the Pretreatment facility is not available, the baseline disposition pathway is not viable. Additionally, some components in the stream are volatile at melter temperatures, thereby accumulating to high concentrations in the scrubbed stream. It would be highly beneficial to divert this stream to an alternate disposition path to alleviate the close-coupled operation of the LAW vitrification and Pretreatment facilities, and to improve long-term throughput and efficiency of the WTP system. In order to determine an alternate disposition path for the LAW SBS/WESP Recycle stream, a range of options are being studied. A simulant of the LAW Off-Gas Condensate was developed, based on the projected composition of this stream, and comparison with pilot-scale testing. The primary radionuclide that vaporizes and accumulates in the stream is Tc-99, but small amounts of several other radionuclides are also projected to be present in this stream. The processes being investigated for managing this stream includes evaporation and radionuclide removal via precipitation and adsorption. During evaporation, it is of interest to investigate the formation of insoluble solids to avoid scaling and plugging of equipment. Key parameters for radionuclide removal include identifying effective precipitation or ion adsorption chemicals, solid-liquid separation methods, and achievable decontamination factors. Results of the radionuclide removal testing indicate that the radionuclides, including Tc-99, can be removed with inorganic sorbents and precipitating agents. Evaporation test results indicate that the simulant can be evaporated to fairly high concentration prior to formation of appreciable solids, but corrosion has not yet been examined.« less

Concentration-Discharge Behavior of Contaminants in a Stream Impacted by Acid Mine Drainage

NASA Astrophysics Data System (ADS)

Shaw, M. E.; Klein, M.; Herndon, E.

2017-12-01

Acid mine drainage (AMD) has severely degraded streams throughout the Appalachian coal region of the United States. AMD occurs when pyrite contained in coal is exposed to water and air during mining activities and oxidized to release high concentrations of sulfate, metals, and acidity into water bodies. Little is known about the concentration-discharge (CQ) relationships of solutes in AMD-impacted streams due to the complicated nature of acid mine drainage systems. For example, streams may receive inputs from multiple sources that include runoff, constructed treatment systems, and abandoned mines that bypass these systems to continue to contaminate the streams. It is important to understand the CQ relationships of contaminants in AMD-impacted streams in order to elucidate contaminant sources and to predict effects on aquatic ecosystems. Here, we study the CQ behaviors of acid and metals in a contaminated watershed in northeastern Ohio where limestone channels have been installed to remediate water draining from a mine pool into the stream. Stream chemistry was measured in samples collected once per day or once per hour during storm events, and stream flow was measured continuously at the watershed outlet. Increases in stream velocity during storm events resulted in an increase in pH (from 3 to 6) that subsequently decreased back to 3 as flow decreased. Additionally, Fe and Mn concentrations in the stream were high during baseflow (7 and 15 mg/L, respectively) and decreased with increasing discharge during storm events. These results indicate that the treatment system is only effective at neutralizing stream acidity and removing metals when water flow through the limestone channel is continuous. We infer that the acidic and metal-rich baseflow derives from upwelling of contaminated groundwater or subsurface flow from a mine pool. Ongoing studies aim to isolate the source of this baseflow contamination and evaluate the geochemical transformations that occur as it flows into the stream.

Nitrogen transport from tallgrass prairie watersheds

USGS Publications Warehouse

Dodds, W.K.; Blair, J.M.; Henebry, G.M.; Koelliker, J.K.; Ramundo, R.; Tate, C.M.

1996-01-01

Discharge and N content of surface water flowing from four Karat watersheds on Konza Prairie Research Natural Area, Kansas, managed with different burn frequencies, were monitored from 1986 to 1992. The goal was to establish the influence of natural processes (climate, fire, and bison grazing) on N transport and concentration in streams. Streams were characterized by variable flow, under conditions that included an extreme flood and a drought during which all channels were dry for over a year. The estimated groundwater/stream water discharge ratio varied between 0.15 to 6.41. Annual N transport by streams, averaged across all watersheds and years, was 0.16 kg N ha-1 yr-1. Annual N transport per unit area also increased as the watershed area increased and as precipitation increased. Total annual transport of N horn the prairie via streams ranged from 0.01 to 6.0% of the N input from precipitation. Nitrate and total N concentrations in surface water decreased (P < 0.001, r values ranged from 0.140.26) as length of time since last fire increased. Increased watershed area was correlated negatively (P < 0.0001) to stream water concentrations of NO3-N and total N (r values = -0.43 and -0.20, respectively). Low N concentration is typical of these streams, with NH4/+-N concentrations below 1.0 ??g L-1, NO3-N ranging from below 1.4 to 392 ??g L-1, and total N from 3.0 to 714 ??g L-1. These data provide an important baseline for evaluating N transport and stream water quality from unfertilized grasslands.

Sources, transformations, and hydrological processes that control stream nitrate and dissolved organic matter concentrations during snowmelt in an upland forest

USGS Publications Warehouse

Sebestyen, Stephen D.; Boyer, Elizabeth W.; Shanley, James B.; Kendall, Carol; Doctor, Daniel H.; Aiken, George R.; Ohte, Nobuhito

2008-01-01

We explored catchment processes that control stream nutrient concentrations at an upland forest in northeastern Vermont, USA, where inputs of nitrogen via atmospheric deposition are among the highest in the nation and affect ecosystem functioning. We traced sources of water, nitrate, and dissolved organic matter (DOM) using stream water samples collected at high frequency during spring snowmelt. Hydrochemistry, isotopic tracers, and end‐member mixing analyses suggested the timing, sources, and source areas from which water and nutrients entered the stream. Although stream‐dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) both originated from leaching of soluble organic matter, flushing responses between these two DOM components varied because of dynamic shifts of hydrological flow paths and sources that supply the highest concentrations of DOC and DON. High concentrations of stream water nitrate originated from atmospheric sources as well as nitrified sources from catchment soils. We detected nitrification in surficial soils during late snowmelt which affected the nitrate supply that was available to be transported to streams. However, isotopic tracers showed that the majority of nitrate in upslope surficial soil waters after the onset of snowmelt originated from atmospheric sources. A fraction of the atmospheric nitrogen was directly delivered to the stream, and this finding highlights the importance of quick flow pathways during snowmelt events. These findings indicate that interactions among sources, transformations, and hydrologic transport processes must be deciphered to understand why concentrations vary over time and over space as well as to elucidate the direct effects of human activities on nutrient dynamics in upland forest streams.

Tissue concentrations of organic contaminants in fish and their biological effects in a wastewater-dominated urban stream

USDA-ARS?s Scientific Manuscript database

Data are presented on the fish tissue concentrations of persistent organic compounds and alkylphenol and alkylphenol ethoxylates (APEs) in large-mouth bass collected from a waste water dominated stream in downtown Chicago. The fish residue concentrations of APEs are compared to concentrations of th...

Sediment concentration and turbidity changes during culvert removals

Treesearch

Randy B. Foltz; Kristina A. Yanosek; Timothy M. Brown

2008-01-01

The concentrations of sediment and turbidity in stream water were monitored during culvert removals to determine the short term effects of road obliteration. Sediment concentration was measured at 11 stream crossings among two locations in Idaho and one in Washington. Sediment concentration immediately below the culvert outlet exceeded levels above the culvert outlet...

MEETING IN PHILADELPHIA: NUTRIENT CONCENTRATIONS IN FLOWING WATERS OF THE SOUTH FORK BROAD RIVER, GEORGIA WATERSHED

EPA Science Inventory

The objective of this poster is by comparing nutrient and DOM concentrations in small and large streams, we hope to better understand: (1) watershed controls on stream nutrient and DOM concentrations; and (2) the variability of nutrient and DOM concentrations within a river netwo...

Phosphorus transport pathways to streams in tile-drained agricultural watersheds.

PubMed

Gentry, L E; David, M B; Royer, T V; Mitchell, C A; Starks, K M

2007-01-01

Agriculture is a major nonpoint source of phosphorus (P) in the Midwest, but how surface runoff and tile drainage interact to affect temporal concentrations and fluxes of both dissolved and particulate P remains unclear. Our objective was to determine the dominant form of P in streams (dissolved or particulate) and identify the mode of transport of this P from fields to streams in tile-drained agricultural watersheds. We measured dissolved reactive P (DRP) and total P (TP) concentrations and loads in stream and tile water in the upper reaches of three watersheds in east-central Illinois (Embarras River, Lake Fork of the Kaskaskia River, and Big Ditch of the Sangamon River). For all 16 water year by watershed combinations examined, annual flow-weighted mean TP concentrations were >0.1 mg L(-1), and seven water year by watershed combinations exceeded 0.2 mg L(-1). Concentrations of DRP and particulate P (PP) increased with stream discharge; however, particulate P was the dominant form during overland runoff events, which greatly affected annual TP loads. Concentrations of DRP and PP in tiles increased with discharge, indicating tiles were a source of P to streams. Across watersheds, the greatest DRP concentrations (as high as 1.25 mg L(-1)) were associated with a precipitation event that followed widespread application of P fertilizer on frozen soils. Although eliminating this practice would reduce the potential for overland runoff of P, soil erosion and tile drainage would continue to be important transport pathways of P to streams in east-central Illinois.

Invertebrate and fish assemblage relations to dissolved Oxygen minima in lowland streams of southwestern Louisiana

USGS Publications Warehouse

Justus, B.G.; Mize, Scott V.; Kroes, Daniel; Wallace, James E.

2012-01-01

Dissolved oxygen (DO) concentrations in lowland streams are naturally lower than those in upland streams; however, in some regions where monitoring data are lacking, DO criteria originally established for upland streams have been applied to lowland streams. This study investigated the DO concentrations at which fish and invertebrate assemblages at 35 sites located on lowland streams in southwestern Louisiana began to demonstrate biological thresholds.Average threshold values for taxa richness, diversity and abundance metrics were 2.6 and 2.3 mg/L for the invertebrate and fish assemblages, respectively. These thresholds are approximately twice the DO concentration that some native fish species are capable of tolerating and are comparable with DO criteria that have been recently applied to some coastal streams in Louisiana and Texas. DO minima >2.5 mg/L were favoured for all but extremely tolerant taxa. Extremely tolerant taxa had respiratory adaptations that gave them a competitive advantage, and their success when DO minima were <2 mg/L could be related more to reductions in competition or predation than to DO concentration directly.DO generally had an inverse relation to the amount of agriculture in the buffer area; however, DO concentrations at sites with both low and high amounts of agriculture (including three least-disturbed sites) declined to <2.5 mg/L. Thus, although DO fell below a concentration that was identified as an approximate biological threshold, sources of this condition were sometimes natural (allochthonous material) and had little relation to anthropogenic activity.

National Uranium Resource Evaluation Program. Hydrogeochemical and stream sediment reconnaissance basic data for Beeville NTMS Quadrangle, Texas. Uranium resource evaluation project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Results of a reconnaissance geochemical survey of the Beeville Quadrangle, Texas are reported. Field and laboratory data are presented for 373 groundwater and 364 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. The groundwater data indicate that the northwestern corner of the quadrangle is the most favorable for potential uranium mineralization. Favorability is indicated by high uranium concentrations; high arsenic, molybdenum, and vanadium concentrations;more » and proximity and similar geologic setting to the mines of the Karnes County mining district. Other areas that appear favorable are an area in Bee and Refugio Counties and the northeastern part of the quadrangle. Both areas have water chemistry similar to the Karnes County area, but the northeastern area does not have high concentrations of pathfinder elements. The stream sediment data indicate that the northeastern corner of the quadrangle is the most favorable for potential mineralization, but agricultural practices and mineralogy of the outcropping Beaumont Formation may indicate a false anomaly. The northwestern corner of the quadrangle is considered favorable because of its proximity to the known uranium deposits, but the data do not seem to support this.« less

Sources and yields of dissolved carbon in northern Wisconsin stream catchments with differing amounts of Peatland

USGS Publications Warehouse

Elder, J.F.; Rybicki, N.B.; Carter, V.; Weintraub, V.

2000-01-01

In five tributary streams (four inflowing and one outflowing) of 1600-ha Trout Lake in northern Wisconsin, USA, we examined factors that can affect the magnitude of stream flow and transport of dissolved organic and inorganic carbon (DOC and DIC) through the streams to the lake. One catchment, the Allequash Creek basin, was investigated in more detail to describe the dynamics of carbon flow and to identify potential carbon sources. Stream flows and carbon loads showed little or no relation to surface-water catchment area. They were more closely related to ground-water watershed area because ground-water discharge, from both local and regional sources, is a major contributor to the hydrologic budgets of these catchments. An important factor in determining carbon influx to the stream is the area of peatland in the catchment. Peatland porewaters contain DOC concentrations up to 40 mg l-1 and are a significant potential carbon source. Ground-water discharge and lateral flow through peat are the suspected mechanisms for transport of that carbon to the streams. Carbon and nitrogen isotopes suggested that the sources of DOC in Allequash Creek above Allequash Lake were wetland vegetation and peat and that the sources below Allequash Lake were filamentous algae and wild rice. Catchments with high proportions of peatland, including the Allequash Creek catchment, tended to have elevated DOC loads in outflowing stream water. Respiration and carbon mineralization in lakes within the system tend to produce low DOC and low DOC/DIC in lake outflows, especially at Trout Lake. In Allequash Lake, however, the shallow peat island and vegetation-filled west end were sources of DOC. Despite the vast carbon reservoir in the peatlands, carbon yields were very low in these catchments. Maximum yields were on the order of 2.5 g m-2 y-1 DOC and 5.5 g m-2 y-1 DIC. The small yields were attributable to low stream flows due to lack of significant overland runoff and very limited stream channel coverage of the total catchment area.

The role of dynamic surface water-groundwater exchange on streambed denitrification in a first-order, low-relief agricultural watershed

NASA Astrophysics Data System (ADS)

Rahimi, Mina; Essaid, Hedeff I.; Wilson, John T.

2015-12-01

The role of temporally varying surface water-groundwater (SW-GW) exchange on nitrate removal by streambed denitrification was examined along a reach of Leary Weber Ditch (LWD), Indiana, a small, first-order, low-relief agricultural watershed within the Upper Mississippi River basin, using data collected in 2004 and 2005. Stream stage, GW heads (H), and temperatures (T) were continuously monitored in streambed piezometers and stream bank wells for two transects across LWD accompanied by synoptic measurements of stream stage, H, T, and nitrate (NO3) concentrations along the reach. The H and T data were used to develop and calibrate vertical two-dimensional, models of streambed water flow and heat transport across and along the axis of the stream. Model-estimated SW-GW exchange varied seasonally and in response to high-streamflow events due to dynamic interactions between SW stage and GW H. Comparison of 2004 and 2005 conditions showed that small changes in precipitation amount and intensity, evapotranspiration, and/or nearby GW levels within a low-relief watershed can readily impact SW-GW interactions. The calibrated LWD flow models and observed stream and streambed NO3 concentrations were used to predict temporal variations in streambed NO3 removal in response to dynamic SW-GW exchange. NO3 removal rates underwent slow seasonal changes, but also underwent rapid changes in response to high-flow events. These findings suggest that increased temporal variability of SW-GW exchange in low-order, low-relief watersheds may be a factor contributing their more efficient removal of NO3.

The role of dynamic surface water-groundwater exchange on streambed denitrification in a first-order, low-relief agricultural watershed

USGS Publications Warehouse

Rahimi Kazerooni, Mina N.; Essaid, Hedeff I.; Wilson, John T.

2015-01-01

The role of temporally varying surface water-groundwater (SW-GW) exchange on nitrate removal by streambed denitrification was examined along a reach of Leary Weber Ditch (LWD), Indiana, a small, first-order, low-relief agricultural watershed within the Upper Mississippi River basin, using data collected in 2004 and 2005. Stream stage, GW heads (H), and temperatures (T) were continuously monitored in streambed piezometers and stream bank wells for two transects across LWD accompanied by synoptic measurements of stream stage, H, T, and nitrate (NO3) concentrations along the reach. The H and T data were used to develop and calibrate vertical two-dimensional, models of streambed water flow and heat transport across and along the axis of the stream. Model-estimated SW-GW exchange varied seasonally and in response to high-streamflow events due to dynamic interactions between SW stage and GW H. Comparison of 2004 and 2005 conditions showed that small changes in precipitation amount and intensity, evapotranspiration, and/or nearby GW levels within a low-relief watershed can readily impact SW-GW interactions. The calibrated LWD flow models and observed stream and streambed NO3 concentrations were used to predict temporal variations in streambed NO3 removal in response to dynamic SW-GW exchange. NO3 removal rates underwent slow seasonal changes, but also underwent rapid changes in response to high-flow events. These findings suggest that increased temporal variability of SW-GW exchange in low-order, low-relief watersheds may be a factor contributing their more efficient removal of NO3.

Transitioning Streaming to Trapping in DC Insulator-based Dielectrophoresis for Biomolecules

PubMed Central

Camacho-Alanis, Fernanda; Gan, Lin; Ros, Alexandra

2012-01-01

Exploiting dielectrophoresis (DEP) to concentrate and separate biomolecules has recently shown large potential as a microscale bioanalytical tool. Such efforts however require tailored devices and knowledge of all interplaying transport mechanisms competing with dielectrophoresis (DEP). Specifically, a strong DEP contribution to the overall transport mechanism is necessary to exploit DEP of biomolecules for analytical applications such as separation and fractionation. Here, we present improved microfluidic devices combining optical lithography and focused ion beam milling (FIBM) for the manipulation of DNA and proteins using insulator-based dielectrophoresis (iDEP) and direct current (DC) electric fields. Experiments were performed on an elastomer platform forming the iDEP microfluidic device with integrated nanoposts and nanopost arrays. Microscale and nanoscale iDEP was studied for λ-DNA (48.5 kbp) and the protein bovine serum albumin (BSA). Numerical simulations were adapted to the various tested geometries revealing excellent qualitative agreement with experimental observations for streaming and trapping DEP. Both the experimental and simulation results indicate that DC iDEP trapping for λ-DNA occurs with tailored nanoposts fabricated via FIBM. Moreover, streaming iDEP concentration of BSA is improved with integrated nanopost arrays by a factor of 45 compared to microfabricated arrays. PMID:23441049

Optimization studies on production of a salt-tolerant protease from Pseudomonas aeruginosa strain BC1 and its application on tannery saline wastewater treatment

PubMed Central

Sivaprakasam, Senthilkumar; Dhandapani, Balaji; Mahadevan, Surianarayanan

2011-01-01

Treatment and safe disposal of tannery saline wastewater, a primary effluent stream that is generated by soaking salt-laden hides and skin is one of the major problems faced by the leather manufacturing industries. Conventional treatment methods like solar evaporation ponds and land composting are not eco-friendly as they deteriorate the ground water quality. Though, this waste stream is comprised of high concentration of dissolved proteins the presence of high salinity (1–6 % NaCl by wt) makes it non-biodegradable. Enzymatic treatment is one of the positive alternatives for management of such kind of waste streams. A novel salt-tolerant alkaline protease obtained from P.aeruginosa (isolated from tannery saline wastewater) was used for enzymatic degradation studies. The effect of various physical factors including pH, temperature, incubation time, protein source and salinity on the activity of identified protease were investigated. Kinetic parameters (Km , Vmax) were calculated for the identified alkaline protease at varying substrate concentrations. Tannery saline wastewater treated with identified salt tolerant protease showed 75 % protein removal at 6 h duration and 2 % (v/v) protease addition was found to be the optimum dosage value. PMID:24031785

Chemical Interactions of Uranium in Water, Sediments, and Plants Along a Watershed Adjacent to the Abandoned Jackpile Mine

NASA Astrophysics Data System (ADS)

Blake, J.; De Vore, C. L.; Avasarala, S.; Ali, A.; Roldan, C.; Bowers, F.; Spilde, M.; Artyushkova, K.; Cerrato, J.

2015-12-01

The chemical interactions, mobility, and plant uptake of uranium (U) near abandoned mine wastes was investigated along the Rio Paguate, adjacent to the Jackpile Mine, located in Laguna Pueblo, New Mexico. Elevated U concentrations in surface water adjacent to mine waste range from 30 to 710 μg/L seasonally and decrease to 5.77 to 10.0 μg/L at a wetland 4.5 kilometers downstream of the mine. Although U concentrations in stream water are elevated, aqua regia acid digestions performed on co-located stream bed and stream bank sediments reveal that there is limited U accumulation on sediments along the reach between the mine and wetland, with most sediment concentrations being near the 3 mg/kg crustal average. However, U concentrations in sediments in the wetland are 4 times the background concentrations in the area. Individual results from salt cedar roots, stems, and leaves collected along the river transect show higher U concentrations in the roots adjacent to the mine waste (20 and 55 mg/kg) and lower in the stems and leaves. Translocation values calculated below 1 are evident in many of the plant samples, suggesting that U root to shoot translocation is minimal and U is accumulating in the roots. Concentrations of U in salt cedar roots from downstream of the mine waste decrease to 15 mg/kg. X-ray photoelectron spectroscopy analysis on sediment samples adjacent to the mine waste show a 75:25% ratio of Fe(III) to Fe(II), which can have an effect on adsorption properties. Electron microprobe results suggest that the ore in this area is present as a uranium-phosphate phase. Our results suggest that dilution, uptake by plants, and U sorption to wetland sediments are the dominant factors that help to decrease the U concentrations downstream of the mine.

Concentrations and distribution of manmade organic compounds in the Lake Tahoe Basin, Nevada and California, 1997-99

USGS Publications Warehouse

Lico, Michael S.; Pennington, Nyle

1999-01-01

The U.S. Geological Survey, in cooperation with the Tahoe Regional Planning Agency and the Lahontan Regional Water-Quality Control Board, sampled Lake Tahoe, major tributary streams to Lake Tahoe, and several other lakes in the Lake Tahoe Basin for manmade organic compounds during 1997-99. Gasoline components were found in all samples collected from Lake Tahoe during the summer boating season. Methyl tert-butyl ether (MTBE), benzene, toluene, ethylbenzene, and xylenes (BTEX) were the commonly detected compounds in these samples. Most samples from tributary streams and lakes with no motorized boating had no detectable concentrations of gasoline components. Motorized boating activity appears to be directly linked in space and time to the occurrence of these gasoline components. Other sources of gasoline components to Lake Tahoe, such as the atmosphere, surface runoff, and subsurface flow, are minor compared to the input by motorized boating. Water sampled from Lake Tahoe during mid-winter, when motorized boating activity is low, had no MTBE and only one sample had any detectable BTEX compounds. Soluble pesticides rarely were detected in water samples from the Lake Tahoe Basin. The only detectable concentrations of these compounds were in samples from Blackwood and Taylor Creeks collected during spring runoff. Concentrations found in these samples were low, in the 1 to 4 nanograms per liter range. Organochlorine compounds were detected in samples collected from semipermeable membrane devices (SPMD's) collected from Lake Tahoe, tributary streams, and Upper Angora Lake. In Lake Tahoe, SPMD samples collected offshore from urbanized areas contained the largest number and highest concentrations of organochlorine compounds. The most commonly detected organochlorine compounds were cis- and trans-chlordane, p, p'-DDE, and hexachlorobenzene. In tributary streams, SPMD samples collected during spring runoff generally had higher combined concentrations of organochlorine compounds than those collected during baseflow conditions. Upper Angora Lake had the fewest number of organochlorine compounds detected of all lake samples. Dioxins and furans were not detected in SPMD samples from two sites in Lake Tahoe or from two tributary streams. The number of polycyclic aromatic hydrocarbon (PAH) compounds and their combined concentrations generally were higher in samples from Lake Tahoe than those from tributary streams. Areas of high-motorized boating activity at Lake Tahoe had the largest number and highest concentrations of PAH's. PAH compounds were detected in samples from SPMD's in four of six tributary streams during spring runoff, all tributary streams during baseflow conditions, and at all lake sites. The most commonly detected PAH's in tributary streams during spring runoff were phenanthrene, fluoranthene, pyrene, and chrysene, and during baseflow conditions were phenanthrene, 1-methylphenanthrene, diethylnaphthalene, and pyrene. Upper Truckee River, which has an urban area in its drainage basin, had the largest number and highest combined concentration of PAH's of all stream samples. Bottom-sediment from Lake Tahoe had detectable concentrations of p-cresol, a phenol, in all but one sample. A sample collected near Chambers Lodge contained phenol at an estimated concentration of 4 micrograms per kilogram (?g/kg). Bottom-sediment samples from tributary streams had no detectable concentrations of organochlorine or PAH compounds. Several compounds were detected in bottom sediment from Upper Angora Lake at high concentrations. These compounds and their concentrations were p, p'-DDD (10 ?g/kg), p, p'-DDE (7.4 ?g/kg), 2,6-dimethylnaphthalene (estimated at 190 ?g/kg), pentachlorophenol (3,000 ?g/kg), and p-cresol (4,400 ?g/kg).

Influence of in-stream diel concentration cycles of dissolved trace metals on acute toxicity to one-year-old cutthroat trout (Oncorhynchus clarki lewisi)

USGS Publications Warehouse

Nimick, D.A.; Harper, D.D.; Farag, A.M.; Cleasby, T.E.; MacConnell, Elizabeth; Skaar, D.

2007-01-01

Extrapolating results of laboratory bioassays to streams is difficult, because conditions such as temperature and dissolved metal concentrations can change substantially on diel time scales. Field bioassays conducted for 96 h in two mining-affected streams compared the survival of hatchery-raised, metal-nai??ve westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to dissolved (0.1-??m filtration) metal concentrations that either exhibited the diel variation observed in streams or were controlled at a constant value. Cadmium and Zn concentrations in these streams increased each night by as much as 61 and 125%, respectively, and decreased a corresponding amount the next day, whereas Cu did not display a diel concentration cycle. In High Ore Creek (40 km south of Helena, MT, USA), survival (33%) after exposure to natural diel-fluctuating Zn concentrations (range, 214-634 ??g/L; mean, 428 ??g/L) was significantly (p = 0.008) higher than survival (14%) after exposure to a controlled, constant Zn concentration (422 ??g/L). Similarly, in Dry Fork Belt Creek (70 km southeast of Great Falls, MT, USA), survival (75%) after exposure to diel-fluctuating Zn concentrations (range, 266-522 ??g/L; mean, 399 ??g/L) was significantly (p = 0.022) higher than survival (50%) in the constant-concentration treatment (392 ??g/L). Survival likely was greater in these diel treatments, both because the periods of lower metal concentrations provided some relief for the fish and because toxicity during periods of higher metal concentrations was lessened by the simultaneous occurrence each night of lower water temperatures, which reduce the rate of metal uptake. Based on the present study, current water-quality criteria appear to be protective for streams with diel concentration cycles of Zn (and, perhaps, Cd) for the hydrologie conditions tested. ?? 2007 SETAC.

Traveltime and longitudinal dispersion in Illinois streams

USGS Publications Warehouse

Graf, Julia B.

1986-01-01

Twenty-seven measurements of traveltime and longitudinal dispersion in 10 Illinois streams made from 1975 to 1982 provide data needed for estimating traveltime of peak concentration of a conservative solute, traveltime of the leading edge of a solute cloud, peak concentration resulting from injection of a given quantity of solute, and passage time of solute past a given point on a stream. These four variables can be estimated graphically for each stream from distance of travel and either discharge at the downstream end of the reach or flow-duration frequency. From equations developed from field measurements, the traveltime and dispersion characteristics also can be estimated for other unregulated streams in Illinois that have drainage areas less than about 1,500 square miles. For unmeasured streams, traveltime of peak concentration and of the leading edge of the cloud are related to discharge at the downstream end of the reach and to distance of travel. For both measured and unmeasured streams, peak concentration and passage time are best estimated from the relation of each to traveltime. In measured streams, dispersion efficiency is greater than that predicted by Fickian diffusion theory. The rate of decrease in peak concentration with traveltime is about equal to the rate of increase in passage time. Average velocity in a stream reach, given by the velocity of the center of solute mass in that reach, can be estimated from an equation developed from measured values. The equation relates average reach velocity to discharge at the downstream end of the reach. Average reach velocities computed for 9 of the 10 streams from available equations that are based on hydraulic-geometry relations are high relative to measured values. The estimating equation developed from measured velocities provides estimates of average reach velocity that are closer to measured velocities than are those computed using equations developed from hydraulic-geometry relations.

Influence of Soils, Riparian Zones, and Hydrology on Nutrients, Herbicides, and Biological Relations in Midwestern Agricultural Streams

NASA Astrophysics Data System (ADS)

Porter, S.

2001-12-01

Chemical, biological, and habitat conditions were characterized in 70 streams in the upper Mississippi River basin during August 1997, as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. The study was designed to evaluate algal and macroinvertebrate responses to high agricultural intensity in relation to nonpoint sources of nutrients and herbicides, characteristics of basin soils, wooded-riparian vegetation, and hydrology. Concentrations and forms of nutrients, herbicides and their metabolites, and seston constituents varied significantly with regional differences in soil properties, ground and surface water relations, density of riparian trees, and precedent rainfall-runoff conditions. Dissolved nitrate concentrations were relatively low in streams with high algal productivity; however, nitrate concentrations increased with basin water yield, which was associated with the regional distribution of rainfall during the month prior to the study. Stream productivity and respiration were positively correlated with seston (phytoplankton) chlorophyll concentrations, which were significantly larger in streams in areas with poorly drained soils and low riparian-tree density. Concentrations of dissolved phosphorus were low in streams where periphyton biomass was high. Periphyton biomass was relatively larger in streams with clear water and low abundance of macroinvertebrates that consume algae. Periphyton biomass decreased rapidly with modest increases in the abundance of scrapers such as snails and certain mayfly taxa. Differences in dissolved oxygen, organic carbon, stream velocity, and precedent hydrologic conditions explained much of the variance in macroinvertebrate community structure. The overall number of macroinvertebrate species and number of mayfly, caddisfly, and stonefly (EPT) taxa that are sensitive to organic enrichment were largest in streams with moderate periphyton biomass, in areas with moderately-well drained soils and high riparian-tree density. Regional differences in hydrologic processes can account for significant differences or gradients in chemical and biological conditions in streams that drain a relatively homogeneous landscape.

The impact of solar radiation on the use of dissolved organic matter in two Ozark Streams: Possible role of photo-enhanced humification

NASA Astrophysics Data System (ADS)

Townsend, S. L.; Ziegler, S. E.

2005-05-01

The effect of solar radiation on dissolved organic matter (DOM) utilization was studied in two contrasting streams from June 2002 through October 2004. Moores Creek is an agricultural stream with elevated nutrient and dissolved organic carbon (DOC) concentrations. Huey Hollow is a forested stream with low nutrient and DOC concentrations. A series of experiments were conducted seasonally to assess how solar radiation influenced DOM utilization. Exposure of DOM to solar radiation significantly decreased its utilization during most seasons in both streams. Each stream experienced one seasonal period when exposure of DOM significantly increased bacterial production; during these periods, DOM appeared to be the least bioavailable and most photochemically reactive. Interestingly, in spring when bioavailability of DOM was lowest in Moores Creek solar radiation exposure further reduced DOM bioavailability. Elevated ammonium concentrations during this spring experiment suggest photochemically-enhanced humification may have been an important mechanism influencing DOM cycling. Bioassays using 15N-labeled ammonium indicated no significant effect of elevated ammonium on the utilization of DOM in either stream in fall 2004. Detection of elevated 15N in the DOM fractions, however, would reveal light stimulated humification under elevated ammonium concentrations not detected with the bioassay.

Nutrients in the Nation?s streams and groundwater: National Findings and Implications

USGS Publications Warehouse

Dubrovsky, Neil M.; Hamilton, Pixie A.

2010-01-01

A comprehensive national analysis of the distribution and trends of nutrient concentrations in streams and groundwater from 1992 through 2004 is provided by the National Water-Quality Assessment (NAWQA) Program of the United States Geological Survey (USGS). Findings describe the distribution and causes of varying nutrient concentrations in streams and groundwater throughout the Nation and examine the primary sources that contribute to elevated concentrations. Results show that excessive nutrient enrichment is a widespread cause of ecological degradation in streams and that nitrate contamination of groundwater used for drinking water, particularly shallow domestic wells in agricultural areas, is a continuing human-health concern. Finally, despite major Federal, State and local nonpoint-source nutrient control efforts for streams and watersheds across the Nation, USGS trend analyses for 1993?2003 suggest limited national progress to reduce the impacts of nonpoint sources of nutrients during this period. Instead, concentrations have remained the same or increased in many streams and aquifers across the Nation, and continue to pose risks to aquatic life and human health. This Fact Sheet highlights selected national findings and their implications, and serves as a companion product to the complete analysis reported in the USGS Circular titled ?The Quality of Our Nation?s Waters?Nutrients in the Nation?s Streams and Groundwater, 1992?2004.?

Chemical and biological quality of streams at the Indiana Dunes National Lakeshore, Indiana, 1978-80

USGS Publications Warehouse

Hardy, M.A.

1984-01-01

Wetland drainage contributed significant amounts of organic materials to streams and at times increased concentrations of dissolved sulfate and iron. Dissolved-iron concentrations correlated with dissolved-organic-carbon concentrations in yellow-brown water of Kintzele and Derby ditches.

Metal contamination and post-remediation recovery in the Boulder River watershed, Jefferson County, Montana

USGS Publications Warehouse

Unruh, Daniel M.; Church, Stanley E; Nimick, David A.; Fey, David L.

2009-01-01

The legacy of acid mine drainage and toxic trace metals left in streams by historical mining is being addressed by many important yet costly remediation efforts. Monitoring of environmental conditions frequently is not performed but is essential to evaluate remediation effectiveness, determine whether clean-up goals have been met, and assess which remediation strategies are most effective. Extensive pre- and post-remediation data for water and sediment quality for the Boulder River watershed in southwestern Montana provide an unusual opportunity to demonstrate the importance of monitoring. The most extensive restoration in the watershed occurred at the Comet mine on High Ore Creek and resulted in the most dramatic improvement in aquatic habitat. Removal of contaminated sediment and tailings, and stream-channel reconstruction reduced Cd and Zn concentrations in water such that fish are now present, and reduced metal concentrations in streambed sediment by a factor of c. 10, the largest improvement in the district. Waste removals at the Buckeye/Enterprise and Bullion mine sites produced limited or no improvement in water and sediment quality, and acidic drainage from mine adits continues to degrade stream aquatic habitat. Recontouring of hillslopes that had funnelled runoff into the workings of the Crystal mine substantially reduced metal concentrations in Uncle Sam Gulch, but did not eliminate all of the acidic adit drainage. Lead isotopic evidence suggests that the Crystal mine rather than the Comet mine is now the largest source of metals in streambed sediment of the Boulder River. The completed removal actions prevent additional contaminants from entering the stream, but it may take many years for erosional processes to diminish the effects of contaminated sediment already in streams. Although significant strides have been made, additional efforts to seal draining adits or treat the adit effluent at the Bullion and Crystal mines would need to be completed to achieve the desired restoration.

Natural and artificial radionuclides in the Suez Canal bottom sediments and stream water

NASA Astrophysics Data System (ADS)

El-Tahawy, M. S.; Farouk, M. A.; Ibrahiem, N. M.; El-Mongey, S. A. M.

1994-07-01

Concentration of natural and artificial radionuclides in Suez Canal bottom sediments and stream water have been measured using γ spectrometers based on a hyper-pure Ge detector. The activity concentrations of 238U series, 232Th series and 40K did not exceed 16.0, 15.5 and 500.0 Bq kg-1 dry weight for sediments. The activity concentration of 238U series and 40K did not exceed 0.6 and 18.0 Bq 1-1 for stream water.

Effects of Urbanization on Stream Water Quality in the City of Atlanta, Georgia, USA

NASA Astrophysics Data System (ADS)

Peters, N. E.

2009-05-01

A long-term stream water-quality monitoring network was established in the City of Atlanta (COA) during 2003 to assess baseline water-quality conditions and the effects of urbanization on stream water quality. Routine hydrologically-based manual stream sampling, including several concurrent manual point and equal width increment sampling, was conducted approximately 12 times per year at 21 stations, with drainage areas ranging from 3.7 to 232 km2. Eleven of the stations are real-time (RT) water-quality stations having continuous measures of stream stage/discharge, pH, dissolved oxygen, specific conductance, water temperature, and turbidity, and automatic samplers for stormwater collection. Samples were analyzed for field parameters, and a broad suite of water-quality and sediment-related constituents. This paper summarizes an evaluation of field parameters and concentrations of major ions, minor and trace metals, nutrient species (nitrogen and phosphorus), and coliform bacteria among stations and with respect to watershed characteristics and plausible sources from 2003 through September 2007. The concentrations of most constituents in the COA streams are statistically higher than those of two nearby reference streams. Concentrations are statistically different among stations for several constituents, despite high variability both within and among stations. The combination of routine manual sampling, automatic sampling during stormflows, and real-time water-quality monitoring provided sufficient information about the variability of urban stream water quality to develop hypotheses for causes of water-quality differences among COA streams. Fecal coliform bacteria concentrations of most individual samples at each station exceeded Georgia's water-quality standard for any water-usage class. High chloride concentrations occur at three stations and are hypothesized to be associated with discharges of chlorinated combined sewer overflows, drainage of swimming pool(s), and dissolution and transport during rainstorms of CaCl2, a deicing salt applied to roads during winter storms. Water quality of one stream was highly affected by the dissolution and transport of ammonium alum [NH4Al(SO4)2] from an alum manufacturing plant in the watershed; streamwater has low pH (<5), low alkalinity and high concentrations of minor and trace metals. Several trace metals (Cu, Pb and Zn) exceed acute and chronic water-quality standards and the high concentrations are attributed to washoff from impervious surfaces.

Selected water-quality and biological characteristics of streams in some forested basins of North Carolina, 1985-88

USGS Publications Warehouse

Caldwell, W.S.

1992-01-01

Selected physical, chemical and biological components of streams draining undeveloped, forested basins in North Carolina were characterized on the basis of samples collected at nine sites on streams in basins that ranged in size from 0.67 to 11.2 sq mi. Water analysis included specific conductance, dissolved oxygen, water temperature, suspended sediment, pH, major dissolved constituents, nutrients, minor constituents, organochlorine insecticides, and biochemical oxygen demand. Biological characteristics included fish tissue analysis for minor constituents and synthetic organic compounds, fish community structure, and benthic macroinvertebrates. Precipitation is the source of 10 to 40% of the chloride concentration and 20 to 30% of the sulfate concentration in stormflow. Mean total nitrogen concentrations ranged from 0.16 mg/L during low-flow conditions to 1.2 mg/L during stormflow. Organic nitrogen was 60 to 85% of the total nitrogen concentration. Stream water was free of organochlorine insecticides. DDD, DDE, DDT, Lindane, and Mirex were detected in 18 of 60 samples of streambed material. About 35% of fish tissue analyses showed detectable concentrations of copper, lead, mercury and nickel. Synthetic organic chemicals were not detected in fish tissue. Fish community structure data were rated using Karr's Index of Biotic Integrity. Streams rated poor to good because of natural stresses on fish communities. Five streams in the Piedmont and mountains received excellent bioclassification ratings based on benthic macroinvertebrtate data. Two streams in the Coastal Plain rated good to fair because of natural stresses.

Modeling hyporheic zone processes

USGS Publications Warehouse

Runkel, Robert L.; McKnight, Diane M.; Rajaram, Harihar

2003-01-01

Stream biogeochemistry is influenced by the physical and chemical processes that occur in the surrounding watershed. These processes include the mass loading of solutes from terrestrial and atmospheric sources, the physical transport of solutes within the watershed, and the transformation of solutes due to biogeochemical reactions. Research over the last two decades has identified the hyporheic zone as an important part of the stream system in which these processes occur. The hyporheic zone may be loosely defined as the porous areas of the stream bed and stream bank in which stream water mixes with shallow groundwater. Exchange of water and solutes between the stream proper and the hyporheic zone has many biogeochemical implications, due to differences in the chemical composition of surface and groundwater. For example, surface waters are typically oxidized environments with relatively high dissolved oxygen concentrations. In contrast, reducing conditions are often present in groundwater systems leading to low dissolved oxygen concentrations. Further, microbial oxidation of organic materials in groundwater leads to supersaturated concentrations of dissolved carbon dioxide relative to the atmosphere. Differences in surface and groundwater pH and temperature are also common. The hyporheic zone is therefore a mixing zone in which there are gradients in the concentrations of dissolved gasses, the concentrations of oxidized and reduced species, pH, and temperature. These gradients lead to biogeochemical reactions that ultimately affect stream water quality. Due to the complexity of these natural systems, modeling techniques are frequently employed to quantify process dynamics.

Chronic and episodic acidification of Adirondack streams from acid rain in 2003-2005

USGS Publications Warehouse

Lawrence, G.B.; Roy, K.M.; Baldigo, Barry P.; Simonin, H.A.; Capone, S.B.; Sutherland, J.W.; Nierzwicki-Bauer, S. A.; Boylen, C.W.

2008-01-01

Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km2 in the western part of the Adirondack region. Acidification was evaluated with the newly developed base-cation surplus (BCS) and the conventional acid-neutralizing capacity by Gran titration (ANCG). During the survey when stream water was most acidic (March 2004), 105 of 188 streams (56%) were acidified based on the criterion of BCS < 0 ??eq L-1, whereas 29% were acidified based on an ANCG value < 0 ??eq L-1. During the survey when stream water was least acidic (August 2003), 15 of 129 streams (12%) were acidified based on the criterion of BCS < 0 ??eq L-1, whereas 5% were acidified based on ANCG value < 0 ??eq L -1. The contribution of acidic deposition to stream acidification was greater than that of strongly acidic organic acids in each of the surveys by factors ranging from approximately 2 to 5, but was greatest during spring snowmelt and least during elevated base flow in August. During snowmelt, the percentage attributable to acidic deposition was 81%, whereas during the October 2003 survey, when dissolved organic carbon (DOC) concentrations were highest, this percentage was 66%. The total length of stream reaches estimated to be prone to acidification was 718 km out of a total of 1237 km of stream reaches that were assessed. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Nutrient Concentrations and Their Relations to the Biotic Integrity of Nonwadeable Rivers in Wisconsin

USGS Publications Warehouse

Robertson, Dale M.; Weigel, Brian M.; Graczyk, David J.

2008-01-01

Excessive nutrient [phosphorus (P) and nitrogen (N)] input from point and nonpoint sources is frequently associated with degraded water quality in streams and rivers. Point-source discharges of nutrients are fairly constant and are controlled by the U.S. Environmental Protection Agency's (USEPA) National Pollutant Discharge Elimination System. To reduce inputs from nonpoint sources, agricultural performance standards and regulations for croplands and livestock operations are being proposed by various States. In addition, the USEPA is establishing regionally based nutrient criteria that can be refined by each State to determine whether actions are needed to improve water quality. More confidence in the environmental benefits of the proposed performance standards and nutrient criteria would be possible with improved understanding of the biotic responses to a range of nutrient concentrations in different environmental settings. To achieve this general goal, the U.S. Geological Survey and the Wisconsin Department of Natural Resources collected data from 282 streams and rivers throughout Wisconsin during 2001 through 2003 to: (1) describe how nutrient concentrations and biotic-community structure differ throughout the State, (2) determine which environmental characteristics are most strongly related to the distribution of nutrient concentrations and biotic-community structure, (3) determine reference conditions for water quality and biotic indices for streams and rivers in the State, (4) determine how the biotic communities in streams and rivers in different areas of the State respond to differences in nutrient concentrations, (5) determine the best regionalization scheme to describe the patterns in reference conditions and the corresponding responses in water quality and the biotic communities (primarily for smaller streams), and (6) develop algorithms to estimate nutrient concentrations in streams and rivers from a combination of biotic indices. The ultimate goal of this study is to provide the information needed to guide the development of regionally based nutrient criteria for Wisconsin streams and rivers. In this report, data collected, primarily in 2003, from 42 nonwadeable rivers are used to describe nutrient concentrations and their relations to the biotic integrity of rivers in Wisconsin. In a separate report by Robertson and others (2006a), the data collected from 240 wadeable streams are used to describe these relations in streams in Wisconsin. Reference water-quality conditions for nonwadeable rivers were found to be similar throughout Wisconsin (approximately 0.035 milligrams per liter (mg/L) for total P (TP), 0.500 mg/L for total N (TN), 4 micrograms per liter for suspended chlorophyll a (SCHL), and greater than 110 centimeters for Secchi-tube depth (SD)). For each category of the biotic community (SCHL, macroinvertebrates, and fish), a few indices were more strongly related to differences in nutrient concentrations than were others. For the indices most strongly related to nutrient concentrations, reference conditions were obtained with a regression approach, from values corresponding to the worst 75th-percentile value from a subset of minimally impacted streams (streams having reference nutrient concentrations), and from the best 25th-percentile value of all the data. Concentrations of TP and TN in nonwadeable rivers increased as the percentage of agricultural land in the basin increased; these increases resulted in increased SCHL concentrations and decreased SDs. The responses in SDs and SCHL concentrations to changes in nutrient concentrations were similar throughout most of the State except in rivers in the southeastern part, where SCHL concentrations were lower than would be expected given their nutrient concentrations. Rivers in the southeastern part of the State had high concentrations of total suspended sediment compared to the SCHL concentrations. Many biotic indices responded to increases in nu

Water quality of streams tributary to Lakes Superior and Michigan

USGS Publications Warehouse

Zimmerman, Jerome W.

1968-01-01

Water quality of streams tributary to Lakes Superior and Michigan was analyzed for 142 stations on 99 streams tributary to Lake Superior and 83 stations on 56 streams tributary to Lake Michigan during 1962-65. Concentrations of aluminum, copper, and iron were not affected greatly by flow or season. Magnesium, calcium, chlorides, total alkalinity, total hardness, and conductivity varied with the flow, temperature, and season; the lowest values were during the spring runoff and heavy rains, and the highest were during low water in late summer and the colder periods of winter. Concentrations of nitrate, silica, and sulfates were lowest in the spring and summer. Concentrations of tanninlike and ligninlike compounds were highest during the spring runoff and other high-water periods, and were lowest during freezeup when surface runoff was minimal. The pH values were highest from June to September and lowest during the spring runoff. Phenolphthalein alkalinity was detected primarily in the summer and coincided occasionally with low flows just before the spring thaw. Total hardness usually was lower in streams tributary to Lake Superior than in streams tributary to Lake Michigan. The total hardness was higher in the streams in Wisconsin than in the streams in Michigan along the west shore of Lake Michigan. It was lowest in the northernmost streams. The water quality of the streams in an area was related to the geological characteristics of the land.

Process recognition in multi-element soil and stream-sediment geochemical data

USGS Publications Warehouse

Grunsky, E.C.; Drew, L.J.; Sutphin, D.M.

2009-01-01

Stream-sediment and soil geochemical data from the Upper and Lower Coastal Plains of South Carolina (USA) were studied to determine relationships between soils and stream sediments. From multi-element associations, characteristic compositions were determined for both media. Primary associations of elements reflect mineralogy, including heavy minerals, carbonates and clays, and the effects of groundwater. The effects of groundwater on element concentrations are more evident in soils than stream sediments. A "winnowing index" was created using ratios of Th to Al that revealed differing erosional and depositional environments. Both soils and stream sediments from the Upper and Lower Coastal Plains show derivation from similar materials and subsequent similar multi-element relationships, but have some distinct differences. In the Lower Coastal Plain, soils have high values of elements concentrated in heavy minerals (Ce, Y, Th) that grade into high values of elements concentrated into finer-grain-size, lower-density materials, primarily comprised of carbonates and feldspar minerals (Mg, Ca, Na, K, Al). These gradational trends in mineralogy and geochemistry are inferred to reflect reworking of materials during marine transgressions and regressions. Upper Coastal Plain stream-sediment geochemistry shows a higher winnowing index relative to soil geochemistry. A comparison of the 4 media (Upper Coastal Plain soils and stream sediments and Lower Coastal Plain soils and stream sediments) shows that Upper Coastal Plain stream sediments have a higher winnowing index and a higher concentration of elements contained within heavy minerals, whereas Lower Coastal Plain stream sediments show a strong correlation between elements typically contained within clays. It is not possible to calculate a functional relationship between stream sediment-soil compositions for all elements due to the complex history of weathering, deposition, reworking and re-deposition. However, depending on the spatial separation of the stream-sediment and soil samples, some elements are more highly correlated than others. Crown Copyright ?? 2009.

Tracking Changes in Dissolved Organic Matter Patterns in Perennial Headwater Streams Throughout a Hydrologic Year Using In-situ Sensors and Optical Properties

NASA Astrophysics Data System (ADS)

Armstrong, A.; Epting, S.; Hosen, J. D.; Palmer, M.

2015-12-01

Dissolved organic matter (DOM) plays a central role in freshwater streams but key questions remain unanswered about temporal patterns in its quantity and composition. DOM in perennial streams in the temperate zone is a complex mixture reflecting a variety of sources such as leached plant material, organic matter from surrounding soils, and microbial processes in the streams themselves. Headwater perennial streams in the Tuckahoe Creek watershed of the Atlantic coastal plain (Maryland, USA) drain a mosaic of land cover types including row crops, forests, and both forested and marshy small depressional wetlands. Wetland-stream surface hydrologic connections generally occur between mid-fall and late spring, coinciding with peak wetland hydrologic expression (i.e. highest groundwater levels and surface inundation extent). When inundated, these wetlands contain high DOM concentrations, and surface connections may serve as conduits for downstream export. We hypothesized that changes in wetland-stream surface hydrologic connectivity would affect patterns of DOM concentration and composition in these streams. We deployed 6 sondes equipped with fluorescent DOM sensors in 4 perennial streams, 1 forested wetland, and the larger downstream channel draining all study sites for the 2015 water year. The 4 headwater streams drain areas containing forested wetlands and have documented temporary channel connections. Combined with baseflow and stormflow sampling, the sondes provided 15 minute estimates of dissolved organic carbon (DOC) concentrations. This resolution provided insights into patterns of DOC concentration across temporal scales from daily rhythms to seasonal changes, during both baseflow and storm conditions. Discrete measurements of absorbance and fluorescence provided information about DOM composition throughout the study. Together these measurements give a detailed record of DOM dynamics in multiple perennial headwater streams for an entire year. This information could inform future studies, such as investigations into stream network scale thresholds in DOM cycling, carbon cycling modelling for the study region, or understanding the impact of wetlands sometimes considered geographically isolated on downstream ecosystems.

The quality of our Nation's waters-Nutrients in the Nation's streams and groundwater, 1992-2004

USGS Publications Warehouse

Dubrovsky, N.M.; Burow, K.R.; Clark, G.M.; Gronberg, J.M.; Hamilton, P.A.; Hitt, K.J.; Mueller, D.K.; Munn, M.D.; Nolan, B.T.; Puckett, L.J.; Rupert, M.G.; Short, T.M.; Spahr, N.E.; Sprague, L.A.; Wilber, W.G.

2010-01-01

National Findings and Their Implications Although the use of artificial fertilizer has supported increasing food production to meet the needs of a growing population, increases in nutrient loadings from agricultural and, to a lesser extent, urban sources have resulted in nutrient concentrations in many streams and parts of aquifers that exceed standards for protection of human health and (or) aquatic life, often by large margins. Do NAWQA findings substantiate national concerns for aquatic and human health? National Water-Quality Assessment (NAWQA) findings indicate that nutrient concentrations in streams and groundwater in basins with significant agricultural or urban development are substantially greater than naturally occurring or ?background? levels. For example, median concentrations of total nitrogen and phosphorus in agricultural streams are about 6 times greater than background levels. Findings also indicate that concentrations in streams routinely were 2 to 10 times greater than regional nutrient criteria recommended by the U.S. Environmental Protection Agency (USEPA) to protect aquatic life. Such large differences in magnitude suggest that significant reductions in sources of nutrients, as well as greater use of land management strategies to reduce the transport of nutrients to streams, are needed to meet recommended criteria for streams draining areas with significant agricultural and urban development. Nitrate concentrations above the Federal drinking-water standard-or Maximum Contaminant Level (MCL)-of 10 milligrams per liter (mg/L, as nit-ogen) are relatively uncommon in samples from streams used for drinking water or from relatively deep aquifers; the MCL is exceeded, however, in more than 20 percent of shallow (less than 100 feet below the water table) domestic wells in agricultural areas. This finding raises concerns for human health in rural agricultural areas where shallow groundwater is used for domestic supply and may warn of future contamination of deeper groundwater pumped from public-supply wells. Are levels of nutrients in water increasing or decreasing? A decadal assessment of trends in concentrations of nitrogen and phosphorus from about 1993 to 2003 shows minimal changes in those concentrations in the majority of studied streams across the Nation, and more upward than downward trends in concentrations at sites with changes. These findings underscore the need for reductions in nutrient inputs or management strategies that would reduce transport of nutrients to streams. Upward trends were evident among all land uses, including those only minimally affected by agricultural and (or) urban development, which suggests that additional protection of some of our Nation's most pristine streams warrants consideration. The median of nitrate concentrations in groundwater from 495 wells also increased significantly from 3.2 to 3.4 mg/L (6 percent) during about the same period, and the proportion of wells with concentrations of nitrate greater than the MCL increased from 16 to 21 percent. Nitrate concentrations in water in deep aquifers are likely to increase during the next decade as shallow groundwater with elevated concentrations moves downward. The potential for future contamination of the deep aquifers requires attention because these aquifers commonly are used for public water supply, and because restoration of groundwater is costly and difficult. Long-term and consistent monitoring of nutrients, improved accounting of nutrient sources, and improved tracking and modeling of climatic and landscape changes will be essential for distinguishing trends in nutrient concentrations, understanding the causes of those trends, and accurately tracking the effectiveness of strategies implemented to manage nutrients.

The quality of our Nation's waters-Nutrients in the Nation's streams and groundwater, 1992-2004

USGS Publications Warehouse

Dubrovsky, Neil M.; Burow, Karen R.; Clark, Gregory M.; Gronberg, JoAnn M.; Hamilton, Pixie A.; Hitt, Kerie J.; Mueller, David K.; Munn, Mark D.; Nolan, Bernard T.; Puckett, Larry J.; Rupert, Michael G.; Short, Terry M.; Spahr, Norman E.; Sprague, Lori A.; Wilber, William G.

2010-01-01

National Findings and Their ImplicationsAlthough the use of artificial fertilizer has supported increasing food production to meet the needs of a growing population, increases in nutrient loadings from agricultural and, to a lesser extent, urban sources have resulted in nutrient concentrations in many streams and parts of aquifers that exceed standards for protection of human health and (or) aquatic life, often by large margins.Do NAWQA findings substantiate national concerns for aquatic and human health?National Water-Quality Assessment (NAWQA) findings indicate that nutrient concentrations in streams and groundwater in basins with significant agricultural or urban development are substantially greater than naturally occurring or “background” levels. For example, median concentrations of total nitrogen and phosphorus in agricultural streams are about 6 times greater than background levels. Findings also indicate that concentrations in streams routinely were 2 to 10 times greater than regional nutrient criteria recommended by the U.S. Environmental Protection Agency (USEPA) to protect aquatic life. Such large differences in magnitude suggest that significant reductions in sources of nutrients, as well as greater use of land management strategies to reduce the transport of nutrients to streams, are needed to meet recommended criteria for streams draining areas with significant agricultural and urban development.Nitrate concentrations above the Federal drinking-water standard—or Maximum Contaminant Level (MCL)—of 10 milligrams per liter (mg/L, as nitrogen) are relatively uncommon in samples from streams used for drinking water or from relatively deep aquifers; the MCL is exceeded, however, in more than 20 percent of shallow (less than 100 feet below the water table) domestic wells in agricultural areas. This finding raises concerns for human health in rural agricultural areas where shallow groundwater is used for domestic supply and may warn of future contamination of deeper groundwater pumped from public‑supply wells.Are levels of nutrients in water increasing or decreasing?A decadal assessment of trends in concentrations of nitrogen and phosphorus from about 1993 to 2003 shows minimal changes in those concentrations in the majority of studied streams across the Nation, and more upward than downward trends in concentrations at sites with changes. These findings underscore the need for reductions in nutrient inputs or management strategies that would reduce transport of nutrients to streams. Upward trends were evident among all land uses, including those only minimally affected by agricultural and (or) urban development, which suggests that additional protection of some of our Nation’s most pristine streams warrants consideration.The median of nitrate concentrations in groundwater from 495 wells also increased significantly from 3.2 to 3.4 mg/L (6 percent) during about the same period, and the proportion of wells with concentrations of nitrate greater than the MCL increased from 16 to 21 percent. Nitrate concentrations in water in deep aquifers are likely to increase during the next decade as shallow groundwater with elevated concentrations moves downward. The potential for future contamination of the deep aquifers requires attention because these aquifers commonly are used for public water supply, and because restoration of groundwater is costly and difficult.Long-term and consistent monitoring of nutrients, improved accounting of nutrient sources, and improved tracking and modeling of climatic and landscape changes will be essential for distinguishing trends in nutrient concentrations, understanding the causes of those trends, and accurately tracking the effectiveness of strategies implemented to manage nutrients.

Characterizing the surface charge of synthetic nanomembranes by the streaming potential method

PubMed Central

Datta, Subhra; Conlisk, A. T.; Kanani, Dharmesh M.; Zydney, Andrew L.; Fissell, William H.; Roy, Shuvo

2010-01-01

The inference of the surface charge of polyethylene glycol (PEG)-coated and uncoated silicon membranes with nanoscale pore sizes from streaming potential measurements in the presence of finite electric double layer (EDL) effects is studied theoretically and experimentally. The developed theoretical model for inferring the pore wall surface charge density from streaming potential measurements is applicable to arbitrary pore cross-sectional shapes and accounts for the effect of finite salt concentration on the ionic mobilities and the thickness of the deposited layer of PEG. Theoretical interpretation of the streaming potential data collected from silicon membranes having nanoscale pore sizes, with/without pore wall surface modification with PEG, indicates that finite electric double layer (EDL) effects in the pore-confined electrolyte significantly affect the interpretation of the membrane charge and that surface modification with PEG leads to a reduction in the pore wall surface charge density. The theoretical model is also used to study the relative significance of the following uniquely nanoscale factors affecting the interpretation of streaming potential in moderate to strongly charged pores: altered net charge convection by applied pressure differentials, surface-charge effects on ionic conduction, and electroosmotic convection of charges. PMID:20462592

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Cedar Creek, Dekalb and Allen counties, Indiana

USGS Publications Warehouse

Wilber, William G.; Peters, J.G.; Ayers, M.A.; Crawford, Charles G.

1979-01-01

A digital model calibrated to conditions in Cedar Creek was used to develop alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. The model indicates that the dissolved-oxygen concentration of the Auburn wastewater effluent and nitrification are the most significant factors affecting the dissolved-oxygen concentration in Cedar Creek during summer low flows. The observed dissolved-oxygen concentration of the Auburn wastewater effluent was low and averaged 30 percent of saturation. Projected nitrogenous biochemical-oxygen demand loads, from the Indiana State Board of Health, for the Auburn and Waterloo wastewater-treatment facilities will result in violations of the current instream dissolved-oxygen standard (5 mg/l), even with an effluent dissolved-oxygen concentration of 80 percent saturation. Natural streamflow for Cedar Creek upstream from the confluence of Willow and Little Cedar Creeks is small compared with the waste discharge, so benefits of dilution for Waterloo and Auburn are minimal. The model also indicates that, during winter low flows, ammonia toxicity, rather than dissolved oxygen, is the limiting water-quality criterion in the reach of Cedar Creek downstream from the wastewater-treatment facility at Auburn and the confluence of Garrett ditch. Ammonia-nitrogen concentrations predicted for 1978 through 2000 downstream from the Waterloo wastewater-treatment facility do not exceed Indiana water-quality standards for streams. Calculations of the stream 's assimilative capacity indicate that future waste discharge in the Cedar Creek basin will be limited to the reaches between the Auburn wastewater-treatment facility and County Road 68. (Kosco-USGS)

Combined analysis of job and task benzene air exposures among workers at four US refinery operations

PubMed Central

Shin, Jennifer (Mi); Unice, Ken M; Gaffney, Shannon H; Kreider, Marisa L; Gelatt, Richard H; Panko, Julie M

2016-01-01

Workplace air samples analyzed for benzene at four US refineries from 1976 to 2007 were pooled into a single dataset to characterize similarities and differences between job titles, tasks and refineries, and to provide a robust dataset for exposure reconstruction. Approximately 12,000 non-task (>180 min) personal samples associated with 50 job titles and 4000 task (<180 min) samples characterizing 24 tasks were evaluated. Personal air sample data from four individual refineries were pooled based on a number of factors including (1) the consistent sampling approach used by refinery industrial hygienists over time, (2) the use of similar exposure controls, (3) the comparability of benzene content of process streams and end products, (4) the ability to assign uniform job titles and task codes across all four refineries, and (5) our analysis of variance (ANOVA) of the distribution of benzene air concentrations for select jobs/tasks across all four refineries. The jobs and tasks most frequently sampled included those with highest potential contact with refinery product streams containing benzene, which reflected the targeted sampling approach utilized by the facility industrial hygienists. Task and non-task data were analyzed to identify and account for significant differences within job-area, task-job, and task-area categories. This analysis demonstrated that in general, areas with benzene containing process streams were associated with greater benzene air concentrations compared to areas with process streams containing little to no benzene. For several job titles and tasks analyzed, there was a statistically significant decrease in benzene air concentration after 1990. This study provides a job and task-focused analysis of occupational exposure to benzene during refinery operations, and it should be useful for reconstructing refinery workers’ exposures to benzene over the past 30 years. PMID:26862134

Combined analysis of job and task benzene air exposures among workers at four US refinery operations.

PubMed

Burns, Amanda; Shin, Jennifer Mi; Unice, Ken M; Gaffney, Shannon H; Kreider, Marisa L; Gelatt, Richard H; Panko, Julie M

2017-03-01

Workplace air samples analyzed for benzene at four US refineries from 1976 to 2007 were pooled into a single dataset to characterize similarities and differences between job titles, tasks and refineries, and to provide a robust dataset for exposure reconstruction. Approximately 12,000 non-task (>180 min) personal samples associated with 50 job titles and 4000 task (<180 min) samples characterizing 24 tasks were evaluated. Personal air sample data from four individual refineries were pooled based on a number of factors including (1) the consistent sampling approach used by refinery industrial hygienists over time, (2) the use of similar exposure controls, (3) the comparability of benzene content of process streams and end products, (4) the ability to assign uniform job titles and task codes across all four refineries, and (5) our analysis of variance (ANOVA) of the distribution of benzene air concentrations for select jobs/tasks across all four refineries. The jobs and tasks most frequently sampled included those with highest potential contact with refinery product streams containing benzene, which reflected the targeted sampling approach utilized by the facility industrial hygienists. Task and non-task data were analyzed to identify and account for significant differences within job-area, task-job, and task-area categories. This analysis demonstrated that in general, areas with benzene containing process streams were associated with greater benzene air concentrations compared to areas with process streams containing little to no benzene. For several job titles and tasks analyzed, there was a statistically significant decrease in benzene air concentration after 1990. This study provides a job and task-focused analysis of occupational exposure to benzene during refinery operations, and it should be useful for reconstructing refinery workers' exposures to benzene over the past 30 years.

In situ measurements of microbially-catalyzed nitrification and nitrate reduction rates in an ephemeral drainage channel receiving water from coalbed natural gas discharge, Powder River Basin, Wyoming, USA

USGS Publications Warehouse

Harris, S.H.; Smith, R.L.

2009-01-01

Nitrification and nitrate reduction were examined in an ephemeral drainage channel receiving discharge from coalbed natural gas (CBNG) production wells in the Powder River Basin, Wyoming. CBNG co-produced water typically contains dissolved inorganic nitrogen (DIN), primarily as ammonium. In this study, a substantial portion of discharged ammonium was oxidized within 50??m of downstream transport, but speciation was markedly influenced by diel fluctuations in dissolved oxygen (> 300????M). After 300??m of transport, 60% of the initial DIN load had been removed. The effect of benthic nitrogen-cycling processes on stream water chemistry was assessed at 2 locations within the stream channel using acrylic chambers to conduct short-term (2-6??h), in-stream incubations. The highest ambient DIN removal rates (2103????mol N m- 2 h- 1) were found at a location where ammonium concentrations > 350????M. This occurred during light incubations when oxygen concentrations were highest. Nitrification was occurring at the site, however, net accumulation of nitrate and nitrite accounted for < 12% of the ammonium consumed, indicating that other ammonium-consuming processes were also occurring. In dark incubations, nitrite and nitrate consumption were dominant processes, while ammonium was produced rather than consumed. At a downstream location nitrification was not a factor and changes in DIN removal rates were controlled by nitrate reduction, diel fluctuations in oxygen concentration, and availability of electron donor. This study indicates that short-term adaptation of stream channel processes can be effective for removing CBNG DIN loads given sufficient travel distances, but the long-term potential for nitrogen remobilization and nitrogen saturation remain to be determined.

Discrimination of trait-based characteristics by trace element bioaccumulation in riverine fishes

USGS Publications Warehouse

Short, T.M.; DeWeese, L.R.; Dubrovsky, N.M.

2008-01-01

Relations between tissue trace element concentrations and species traits were examined for 45 fish species to determine the extent to which trait-based characteristics accounted for relative differences among species in trace element bioaccumulation. Percentages of fish species correctly classified by discriminant analysis according to traits predicted by tissue trace element concentrations ranged from 72% to 87%. Tissue concentrations of copper, mercury, selenium, and zinc appeared to have the greatest overall influence on differentiating species according to trait characteristics. Discrimination of trait characteristics did not appear to be strongly influenced by local sources of trace elements in the streambed sediment. Bioaccumulation was greatest for those species classified as primarily detritivores, having relatively large adult body size, considered nonmigratory with respect to reproductive strategy, occurring mostly in large or variable size streams and rivers, preferring depositional areas within the stream channel, and preferring benthic rather than open-water habitats. Our findings provide evidence of the strong relationship between bioaccumulation of environmental trace elements and trait-based factors that influence contaminant exposure. ?? 2008 NRC.

Turbidity and total suspended solid concentration dynamics in streamflow from California oak woodland watersheds

Treesearch

David J. Lewis; Kenneth W. Tate; Randy A. Dahlgren; Jacob Newell

2002-01-01

Resource agencies, private landowners, and citizen monitoring programs utilize turbidity (water clarity) measurements as a water quality indicator for total suspended solids (TSS – mass of solids per unit volume) and other constituents in streams and rivers. The dynamics and relationships between turbidity and TSS are functions of watershed-specific factors and...

Trends in pesticide concentrations and use for major rivers of the United States

USGS Publications Warehouse

Ryberg, Karen R.; Gilliom, Robert J.

2015-01-01

Pesticides strongly dominated by agricultural use (cyanazine, alachlor, atrazine and its degradate deethylatrazine, metolachlor, and carbofuran) had widespread agreement between concentration trends and use trends. Pesticides with substantial use in both agricultural and nonagricultural applications (simazine, chlorpyrifos, malathion, diazinon, and carbaryl) had concentration trends that were mostly explained by a combination of agricultural-use trends, regulatory changes, and urban use changes inferred from concentration trends in urban streams. When there were differences, concentration trends usually were greater than use trends (increased more or decreased less). These differences may occur because of such factors as unaccounted pesticide uses, delayed transport to the river through groundwater, greater uncertainty in the use data, or unquantified land use and management practice changes.

Effects of whole-stream nutrient enrichment on the concentration and abundance of aquatic hyphomycete conidia in transport

Treesearch

Vol. 96(1): 57-65 Mycologia

2004-01-01

The concentrations and relative abundances of aquatic hyphomycete conidia in water were followed during a three-year study in two headwater streams at Coweeta Hydrologic Laboratory, North Carolina, using the membrane-filtration technique. After a one-ye& pretreatment period, one of the streams was enriched continuously with inorganic nutrients (N+P) for two years...

Effects of Land Use on Stable Carbon Isotopic Composition and Concentration of Dissolved Organic Carbon (DOC) and Dissolved Inorganic Carbon (DIC) in Southeastern US Piedmont Headwater Streams

EPA Science Inventory

Stable carbon isotopic composition (delta 13C) and concentrations of DOC and DIC were measured in stream water samples collected monthly in 15 headwater streams from an area with extensive poultry and cattle production and a rapidly growing human population. Linear regression te...

Trends in stream nitrogen concentrations for forested reference catchments across the USA

Treesearch

A. Argerich; S.L. Johnson; S.D. Sebestyen; C.C. Rhoades; E. Greathouse; J.D. Knoepp; M.B. Adams; G.E. Likens; J.L. Campbell; W.H. McDowell; F.N. Scatena; G.G. Ice

2013-01-01

To examine whether stream nitrogen concentrations in forested reference catchments have changed over time and if patterns were consistent across the USA, we synthesized up to 44 yr of data collected from 22 catchments at seven USDA Forest Service Experimental Forests. Trends in stream nitrogen presented high spatial variability both among catchments at a site and among...

Road salt in the environment: loads, lags and consequences.

NASA Astrophysics Data System (ADS)

Findlay, S.; Kelly, V.; Martin, L.

2014-12-01

Increased use of road salt over the past few decades has, not surprisingly, led to higher Na and Cl concentrations in dispersed parts of the environment. We have tracked these changes over southeastern New York for the past 20+ years and can show a clear link to road density as an explanatory factor for local concentrations. The unexpected findings center around retention of Cl in streams and shallow groundwaters long after the winter season has passed and this can result in average summertime concentrations as high as monthly mean concentrations during the snoa and ice season. These persisten concentrations have consequences for aquatic life as well as local water resources. Literature suggests these high summer values may cause harm to some sensitive organisms.Experiments show both susceptibility and adaptation by local stream algal communities. Analysis of reported data from private drinking water wells shows a sub-set has Cl levels above the EPA secondary standard and these exceedances are apparently associated with local salt application rates. The problems of rising salt are significant given the magnitude of salt release to the environment but also tractable in the sense that there are multiple motivations for minimizing application rates while maintaining public safety. The salinization issue has also proven a useful tool for public engagement since the problem is widespread yet comprehensible.

Land-based sources of marine pollution: Pesticides, PAHs and phthalates in coastal stream water, and heavy metals in coastal stream sediments in American Samoa.

PubMed

Polidoro, Beth A; Comeros-Raynal, Mia T; Cahill, Thomas; Clement, Cassandra

2017-03-15

The island nations and territories of the South Pacific are facing a number of pressing environmental concerns, including solid waste management and coastal pollution. Here we provide baseline information on the presence and concentration of heavy metals and selected organic contaminants (pesticides, PAHs, phthalates) in 7 coastal streams and in surface waters adjacent to the Futiga landfill in American Samoa. All sampled stream sediments contained high concentrations of lead, and some of mercury. Several coastal stream waters showed relatively high concentrations of diethyl phthalate and of organophosphate pesticides, above chronic toxicity values for fish and other aquatic organisms. Parathion, which has been banned by the US Environmental Protection Agency since 2006, was detected in several stream sites. Increased monitoring and initiatives to limit non-point source land-based pollution will greatly improve the state of freshwater and coastal resources, as well as reduce risks to human health in American Samoa. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inferring Groundwater Age in an Alluvial Aquifer from Tracer Concentrations in the Stream - Little Wind River, Wyoming

NASA Astrophysics Data System (ADS)

Goble, D.; Gardner, W. P.; Naftz, D. L.; Solder, J. E.

2017-12-01

We use environmental tracers: CFC's, SF6, and 222Rn measured in stream water to determine volume and mean age of groundwater discharging to the Little Wind River, near Riverton, Wyoming. Samples of 222Rn were collected every 200 m along a 2 km reach, surrounding a known groundwater discharge zone. Nearby groundwater wells, in-stream piezometers and seepage meters were sampled for 222Rn, CFC's and SF6. Tracer concentrations measured in groundwater and in-stream piezometers were used to estimate the mean age of the subsurface system. High resolution 222Rn samples were used to determine the location and volume of groundwater inflow using a model of instream transport that includes radioactive decay and gas exchange with the atmosphere. The age of groundwater entering the stream was then estimated from in-stream measured CFC and SF6 concentrations using a new coupled stream transport and lumped-parameter groundwater age model. Ages derived from in-stream measurements were then compared to the age of subsurface water measured in piezometers, seepage meters, and groundwater wells. We then asses the ability of groundwater age inferred from in-stream samples to provide constraint on the age of the subsurface discharge to the stream. The ability to asses groundwater age from in-stream samples can provide a convenient method to constrain the regional distribution of groundwater circulation rates when groundwater sampling is challenging or wells are not in place.

Analysis of selected water-quality data for surface water in St. Tammany Parish, Louisiana, April-August 1995

USGS Publications Warehouse

Demcheck, Dennis K.

1996-01-01

Physical and chemical-related properties, concentrations of chemical constituents, which included major ions and nutrients, and concentrations of fecal-coliform bacteria were determined for 17 sites on 11 streams in St. Tammany Parish, Louisiana, during the period April-August 1995. The streams were sampled to assess the effects of different streamflow conditions on the concentrations of water-quality constituents. The streams included in the study were Tchefuncte River, Bogue Falaya, Abita River, Bayou Chinchouba, Bayou Castine, Cane Bayou, Bayou Lacombe, Bayou Liberty, Bayou Bonfouca, Bogue Chitto, and West Pearl River. Water-quality samples were collected under several hydrologic conditions. These conditions included a period of wet weather and sustained high river stages; a period of local storms several days apart and river stages typical of that situation; and a period of dry weather and low river stages. The concentrations of inorganic chemical constituents in water from the upstream sites generally were low. Concentrations from the downstream sites varied and were higher. Nutrient and fecal-coliform bacteria concentrations varied and indicated that degraded water-quality conditions that typically occur during storms persisted less than 1-3 days. In general, the larger the drainage basin, the longer it takes for the stream to recover. Fecal-coliform concen- trations reflected the effects of small, isolated storms in the area. Bayou Castine, sampled immediately after a storm, had a fecal-coliform concentration of 26,000 colonies per 100 milliliters. The stream was resampled 24 hours later, and the fecal-coliform concentration had decreased to 1,700 colonies per 100 milliliters. This is an indication of the rapid water-quality changes that typically occur in small streams.

Diel changes in water chemistry in an arsenic-rich stream and treatment-pond system

USGS Publications Warehouse

Gammons, C.H.; Grant, T.M.; Nimick, D.A.; Parker, S.R.; DeGrandpre, M.D.

2007-01-01

Arsenic concentrations are elevated in surface waters of the Warm Springs Ponds Operable Unit (WSPOU), located at the head of the upper Clark Fork River Superfund site, Montana, USA. Arsenic is derived from historical deposition of smelter emissions (Mill and Willow Creeks) and historical mining and milling wastes (Silver Bow Creek). Although long-term monitoring has characterized the general seasonal and flow-related trends in As concentrations in these streams and the pond system used to treat Silver Bow Creek water, little is known about solubility controls and sorption processes that influence diel cycles in As concentrations. Diel (24-h) sampling was conducted in July 2004 and August 2005 at the outlet of the treatment ponds, at two locations along a nearby reconstructed stream channel that diverts tributary water around the ponds, and at Silver Bow Creek 2??km below the ponds. Dissolved As concentration increased up to 51% during the day at most of the stream sites, whereas little or no diel change was displayed at the treatment-pond outlet. The strong cycle in streams is explained by pH- and temperature-dependent sorption of As onto hydrous metal oxides or biofilms on the streambed. Concentrations of dissolved Ca2+ and HCO3- at the stream sites showed a diel temporal pattern opposite to that of As, and geochemical modeling supports the hypothesis that the concentrations of Ca2+ and HCO3- were controlled by precipitation of calcite during the warm afternoon hours when pH rose above 9.0. Nightly increases in dissolved Mn and Fe(II) concentrations were out of phase with concentrations of other divalent cations and are more likely explained by redox phenomena. ?? 2007 Elsevier B.V. All rights reserved.

Integrative neural networks model for prediction of sediment rating curve parameters for ungauged basins

NASA Astrophysics Data System (ADS)

Atieh, M.; Mehltretter, S. L.; Gharabaghi, B.; Rudra, R.

2015-12-01

One of the most uncertain modeling tasks in hydrology is the prediction of ungauged stream sediment load and concentration statistics. This study presents integrated artificial neural networks (ANN) models for prediction of sediment rating curve parameters (rating curve coefficient α and rating curve exponent β) for ungauged basins. The ANN models integrate a comprehensive list of input parameters to improve the accuracy achieved; the input parameters used include: soil, land use, topographic, climatic, and hydrometric data sets. The ANN models were trained on the randomly selected 2/3 of the dataset of 94 gauged streams in Ontario, Canada and validated on the remaining 1/3. The developed models have high correlation coefficients of 0.92 and 0.86 for α and β, respectively. The ANN model for the rating coefficient α is directly proportional to rainfall erosivity factor, soil erodibility factor, and apportionment entropy disorder index, whereas it is inversely proportional to vegetation cover and mean annual snowfall. The ANN model for the rating exponent β is directly proportional to mean annual precipitation, the apportionment entropy disorder index, main channel slope, standard deviation of daily discharge, and inversely proportional to the fraction of basin area covered by wetlands and swamps. Sediment rating curves are essential tools for the calculation of sediment load, concentration-duration curve (CDC), and concentration-duration-frequency (CDF) analysis for more accurate assessment of water quality for ungauged basins.

Radionuclides and toxic elements transfer from the princess dump to water in Roodepoort, South Africa.

PubMed

Dlamini, S G; Mathuthu, M M; Tshivhase, V M

2016-03-01

High concentrations of radionuclides and toxic elements in gold mine tailings facilities present a health hazard to the environment and people living near that area. Soil and water samples from selected areas around the Princess Mine dump were collected. Soil sampling was done on the surface (15 cm) and also 100 cm below the surface. Water samples were taken from near the dump, mid-stream and the flowing part of the stream (drainage pipe) passing through Roodepoort from the mine dump. Soil samples were analyzed by gamma-ray spectroscopy using a HPGe detector to determine the activity concentrations of (238)U, (232)Th and (4) (​40)K from the activities of the daughter nuclides in the respective decay chains. The average activity concentrations for uranium and thorium in soil were calculated to be 129 ± 36.1 Bq/kg and 18.1 ± 4.01 Bq/kg, respectively. Water samples were analyzed using Inductively Coupled Plasma Mass Spectrometer. Transfer factors for uranium and thorium from soil to water (at point A closest to dump) were calculated to be 0.494 and 0.039, respectively. At point Z2, which is furthest from the dump, they were calculated to be 0.121 and 0.004, respectively. These transfer factors indicate that there is less translocation of the radionuclides as the water flows. Copyright © 2016 Elsevier Ltd. All rights reserved.

The role of wildfires and forest succession in stream biogeochemistry within the continuous permafrost zone of Central Siberia

NASA Astrophysics Data System (ADS)

Prokushkin, Anatoly

2016-04-01

Wildfires transform boreal and subarctic forested landscapes leading to the changes in organic matter and inorganic nutrient turnover in terrestrial ecosystems. To get an insight to the fire effect on C fluxes and general hydrochemical characteristics of streams draining continuous permafrost terrains of Central Siberian Plateau (64o N 100o E), we have selected the chronosequence of basins (n = 17) which were severely affected by fires (>80% of basin area) in the time range from 1 to 116 years ago. Stream waters were sampled continuously during frost free seasons (May-September) of 2006-2015. Four streams have been equipped with water level, temperature and conductivity probes for continuous monitoring. The strongest negative effect of wildfires on dissolved organic carbon (DOC) concentrations in streams has occurred right after a fire event, and minimum mean annual concentrations of DOC appeared between 15 and 20 years elapsed after a fire. The most pronounced decrease in DOC concentrations during an annual cycle found in freshet period (May-June) and summer-fall storm events: differences of DOC concentrations among "intact" (>100 years after fire) and recent fire basins (<6 years) reached as much as 2-fold. Less differentiation among basins appears under lowflow conditions, as DOC-depleted solutes from deeper soil layers become dominating in stream flow. Following the post-fire forest recovery, the seasonal mean DOC concentrations in streams demonstrated linear growth at the rate of ca. 0.11 mgC/l/a and approached the initial values already after ca. 60 years after fire disturbance. An opposite trend (i.e. increasing load to streams after fire impact) was observed for dissolved inorganic carbon, major anions and cations. Sulfate was found to be a good tracer of fire affect as increased 200-fold in stream waters right after a fire and steady decreased at the rate [SO42-] = 3.65 x (year after fire)^-0.75 as terrestrial ecosystems were recovering after a fire. For study area, Na+ and Cl- in streams appear to be good indicators of permafrost degradation as they reflect talik formation and connection of a stream to underlying evaporitic deposits. While evidence of permafrost degradation is currently not apparent in the region, we expect increasing concentrations of Na+ and Cl- in streams of Central Siberian Plateau as permafrost degrades due to decreased fire return interval and warming temperatures. The generalized data of active layer thickness (ALT) within analyzed watersheds have demonstrated that fire-driven deepening of ALT results in increasing stream inorganic compounds concentrations. The inverse relationship found between DOC and ALT might be attributed to deeper infiltration of solutions, sorption of DOC on clay minerals, and an increasing rate of DOC microbiological mineralization to CO2 due to increased soil temperatures. Post-fire forest recovery and, particularly, the accumulation of organic mater in the moss-lichen layer and soil organic horizon on watersheds accounted for increasing mean DOC concentrations in the streams. In opposite, increased insulation of soils by organic matter accumulating on the soil surface leads to steadily decreasing ALT and constrains an infiltration of solutes to subsoil. As a result, inorganic solute loading to stream channels is tended to decrease during post-fire forest succession in permafrost affected terrains.

Influence of geology on arsenic concentrations in ground and surface water in central Lesvos, Greece.

PubMed

Aloupi, Maria; Angelidis, Michael O; Gavriil, Apostolos M; Koulousaris, Michael; Varnavas, Soterios P

2009-04-01

The occurrence of As was studied in groundwater used for human consumption and irrigation, in stream water and sediments and in water from thermal springs in the drainage basin of Kalloni Gulf, island of Lesvos, Greece, in order to investigate the potential influence of the geothermal field of Polichnitos-Lisvori on the ground and surface water systems of the area. Total dissolved As varied in the range <0.7-88.3 microg L(-1) in groundwater, 41.1-90.7 microg L(-1) in thermal spring water and 0.4-13.2 microg L(-1) in stream water, whereas As concentrations in stream sediments varied between 2.0-21.9 mg kg(-1). Four out of 31 groundwater samples exceeded the EC standard of 10 microg L(-1). The survey revealed an enrichment in both surface and groundwater hydrological systems in the northern part of the area (average concentrations of As in groundwater, stream water and stream sediment: 8.0 microg L(-1), 8.8 microg L(-1) and 15.0 mg kg(-1) respectively), in association with the volcanic bedrocks, while lower As concentrations were found in the eastern part (average concentrations in groundwater, stream water and stream sediment: 2.9 microg L(-1), 1.7 microg L(-1) and 5.9 mg kg(-1) respectively), which is dominated by ophiolitic ultramafic formations. The variation of As levels between the different parts of the study area suggests that local geology exerts a determinant influence on As geochemical behaviour. On the other hand, the geothermal activity manifested in the area of Polichnitos-Lisvori does not affect the presence of As in groundwater and streams.

Effects of long-term land use change on dissolved carbon characteristics in the permafrost streams of northeast China.

PubMed

Guo, Yuedong; Song, Changchun; Wan, Zhongmei; Tan, Wenwen; Lu, Yongzheng; Qiao, Tianhua

2014-11-01

Permafrost soils act as large sinks of organic carbon but are highly sensitive to interference such as changes in land use, which can greatly influence dissolved carbon loads in streams. This study examines the effects of long-term land reclamation on seasonal concentrations of dissolved carbons in the upper reaches of the Nenjiang River, northeast China. A comparison of streams in natural and agricultural systems shows that the dissolved organic carbon (DOC) concentration is much lower in the agricultural stream (AG) than in the two natural streams (WAF, wetland dominated; FR, forest dominated), suggesting that land use change is associated with reduced DOC exporting capacity. Moreover, the fluorescence indexes and the ratio of dissolved carbon to nitrogen also differ greatly between the natural and agricultural streams, indicating that the chemical characteristics and the origin of the DOC released from the whole reaches are also altered to some extent. Importantly, the exporting concentration of dissolved inorganic carbon (DIC) and its proportion of total dissolved carbon (TDC) substantially increase following land reclamation, which would largely alter the carbon cycling processes in the downstream fluvial system. Although the strong association between the stream discharge and the DOC concentration was unchanged, the reduction in total soil organic carbon following land reclamation led to remarkable decline of the total flux and exporting coefficient of the dissolved carbons. The results suggest that dissolved carbons in permafrost streams have been greatly affected by changes in land use since the 1970s, and the changes in the concentration and chemical characteristics of dissolved carbons will last until the alteration in both the traditional agriculture pattern and the persistent reclamation activities.

Nutrient variation in an urban lake chain and its consequences for phytoplankton production.

PubMed

Roach, W John; Grimm, Nancy B

2009-01-01

In the Central Arizona-Phoenix (CAP) ecosystem, managers divert mixed stream water and groundwater to maintain an artificial lake chain in Indian Bend Wash (IBW), a historically flashy, ephemeral, desert stream. Nutrient concentrations in the CAP ecosystem's groundwater, stream water, and floodwater differ: stream water has low concentrations of both inorganic N and P, while groundwater is low in inorganic P but rich in nitrate (NO(3)(-)). Consequently, groundwater contribution drives inorganic N concentrations in the lake chain. In contrast, floodwater typically has high P concentrations while remaining low in N. Thus we expected N and P concentrations in IBW lakes to vary with the mix of water flowing through them. Elevated NO(3)(-) and low inorganic P concentrations were predicted when groundwater pumping was pronounced and this prediction was supported. We hypothesized that these predictable changes in water chemistry would affect nutrient limitation of phytoplankton. Laboratory nutrient-addition bioassays demonstrated that phytoplankton growth was P-limited throughout the summer of 2003 when N/P was high. However, after a late-season flood drove N/P below 31:1, the expected threshold between N and P limitation, N limitation was observed. Our results indicate that effects of floods, the preeminent historic drivers of Sonoran Desert stream biogeochemistry, are mitigated in urban ecosystems by decisions about which spigots to turn. Consequently, nutrient limitation of urban streams is driven as much by management decisions as by natural hydrologic variation.

Biogeochemical patterns of intermittent streams over space and time as surface flows decrease

NASA Astrophysics Data System (ADS)

MacNeille, R. B.; Lohse, K. A.; Godsey, S.; McCorkle, E. P.; Parsons, S.; Baxter, C.

2016-12-01

Climate change in the western United States is projected to lead to earlier snowmelt, increasing fire risk and potentially transitioning perennial streams to intermittent ones. Differences between perennial and intermittent streams, especially the temporal and spatial patterns of carbon and nutrient dynamics during periods of drying, are understudied. We examined spatial and temporal patterns in surface water biogeochemistry in southwest Idaho and hypothesized that as streams dry, carbon concentrations would increase due to evapoconcentration and/or increased in-stream production. Furthermore, we expected that biogeochemical patterns of streams would become increasingly spatially heterogeneous with drying. Finally, we expected that these patterns would vary in response to fire. To test these hypotheses, we collected water samples every 50 meters from two intermittent streams, one burned and one unburned, in April, May and June, 2016 to determine surface water biogeochemistry. Results showed average concentrations of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) increased 3-fold from April to June in the burned site compared to the unburned site where concentrations remained relatively constant. Interestingly, average concentrations of total nitrogen (TN) dropped substantially for the burned site over these three months, but only decreased slightly for the unburned site over the same time period. We also assessed changes in spatial correlation between the burned and unburned site: carbon concentrations were less spatially correlated at the unburned site than at the burned site. Scatterplot matrices of DIC values indicated that at a lag distance of 300 m in April and June, the unburned site had r-values of 0.7416 and 0.5975, respectively, while the burned site had r-values of 0.9468 and 0.8783, respectively. These initial findings support our hypotheses that carbon concentrations and spatial heterogeneity increased over time.

Spatial heterogeneity of within-stream methane concentrations

NASA Astrophysics Data System (ADS)

Crawford, John T.; Loken, Luke C.; West, William E.; Crary, Benjamin; Spawn, Seth A.; Gubbins, Nicholas; Jones, Stuart E.; Striegl, Robert G.; Stanley, Emily H.

2017-05-01

Streams, rivers, and other freshwater features may be significant sources of CH4 to the atmosphere. However, high spatial and temporal variabilities hinder our ability to understand the underlying processes of CH4 production and delivery to streams and also challenge the use of scaling approaches across large areas. We studied a stream having high geomorphic variability to assess the underlying scale of CH4 spatial variability and to examine whether the physical structure of a stream can explain the variation in surface CH4. A combination of high-resolution CH4 mapping, a survey of groundwater CH4 concentrations, quantitative analysis of methanogen DNA, and sediment CH4 production potentials illustrates the spatial and geomorphic controls on CH4 emissions to the atmosphere. We observed significant spatial clustering with high CH4 concentrations in organic-rich stream reaches and lake transitions. These sites were also enriched in the methane-producing mcrA gene and had highest CH4 production rates in the laboratory. In contrast, mineral-rich reaches had significantly lower concentrations and had lesser abundances of mcrA. Strong relationships between CH4 and the physical structure of this aquatic system, along with high spatial variability, suggest that future investigations will benefit from viewing streams as landscapes, as opposed to ecosystems simply embedded in larger terrestrial mosaics. In light of such high spatial variability, we recommend that future workers evaluate stream networks first by using similar spatial tools in order to build effective sampling programs.

Tracing Nitrogen Sources in Forested Catchments Under Varying Flow Conditions: Seasonal and Event Scale Patterns

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Kendall, C.

2004-12-01

Our ability to assess how stream nutrient concentrations respond to biogeochemical transformations and stream flow dynamics is often limited by datasets that do not include all flow conditions that occur over event, monthly, seasonal, and yearly time scales. At the Sleepers River Research Watershed in northeastern Vermont, USA, nitrate, DOC (dissolved organic carbon), and major ion concentrations were measured on samples collected over a wide range of flow conditions from summer 2002 through summer 2004. Nutrient flushing occurred at the W-9 catchment and high-frequency sampling revealed critical insights into seasonal and event-scale controls on nutrient concentrations. In this seasonally snow-covered catchment, the earliest stage of snowmelt introduced nitrogen directly to the stream from the snowpack. As snowmelt progressed, the source of stream nitrate shifted to flushing of soil nitrate along shallow subsurface flow paths. In the growing season, nitrogen flushing to streams varied with antecedent moisture conditions. More nitrogen was available to flush to streams when antecedent moisture was lowest, and mobile nitrogen stores in the landscape regenerated under baseflow conditions on times scales as short as 7 days. Leaf fall was another critical time when coupled hydrological and biogeochemical processes controlled nutrient fluxes. With the input of labile organic carbon from freshly decomposing leaves, nitrate concentrations declined sharply in response to in-stream immobilization or denitrification. These high-resolution hydrochemical data from multiple flow regimes are identifying "hot spots" and "hot moments" of biogeochemical and hydrological processes that control nutrient fluxes in streams.

Legacy and emerging halogenated flame retardants in the middle and lower stream of the Yellow River.

PubMed

Su, Xianfa; Li, Qilu; Feng, Jinglan; Guo, Liya; Sun, Jianhui

2017-12-01

Halogenated flame retardants (HFRs), mainly encompassing polybrominated diphenylethers (PBDEs), dechlorane plus (DP) and emerging bromine flame retardants (EBFRs), are widely employed nowadays in daily lives. However, limited knowledge has been gained to date on the concentrations and distributions of HFRs in particular within certain regions. In the present study, legacy and emerging HFRs were systematically measured in suspended particle matter (SPM) and sediments collected in 2014 from the middle and lower reach of the Yellow River in Henan province. The total concentrations of HFRs in SPM among the three seasons were 42.2±91.2ngg -1 , which was far higher than the corresponding values of HFRs in sediments (1.82±2.94ngg -1 ). In this study, PBDEs, DP and EBFRs in sediment almost exhibited relatively lower levels as compared to those found in other studies, where the limited usage of HFRs in the middle and lower stream of the Yellow River was probably the major impact factor. EBFR was the predominate pollutant from SPM and sediments in most of the sampling sites, suggesting that EBFRs were widely used nowadays as substitute materials of 'old' FRs. The mean concentration values of DBDPE/BDE-209 in SPM and sediments were apparently higher than those of previous studies. Furthermore, it is interesting to reveal that herein almost all of the HFR concentrations were unrelated to the population and GDP, which might be attributed to the characteristics of 'elevated stream' of the Yellow River as well as the complex river systems in Henan province. Copyright © 2017 Elsevier B.V. All rights reserved.

Biophysical Controls on Carbon Cycling in Restored and Unrestored Urban Streams

NASA Astrophysics Data System (ADS)

Larsen, L. G.; Harvey, J. W.; Singh, J. D.; Sinclair, G. A.; Langston, T.; Maglio, M. M.

2012-12-01

Stream restoration is a multibillion dollar industry, yet how restoration impacts the ecological functioning of streams remains poorly understood. Because stream restoration may alter numerous biophysical controls, including light availability (through tree removal during bank regrading), hydraulics, sediment characteristics, and/or nutrient concentrations, it can be challenging to achieve a general understanding of how different aspects of stream restoration design influence ecosystem function (e.g., carbon cycling). In this study we combined strategies of continuously monitoring hydrology, turbidity, and dissolved oxygen at a station with spatially distributed but temporally sparse synoptic sampling to understand how restoration and land-use impact carbon fixation and respiration in urban streams. The study was performed over three years in three adjacent 3rd-4th order stream reaches in the urban Chesapeake Bay watershed, one of which was restored in 2002 using the ubiquitous Natural Channel Design method. By parsing the dissolved oxygen time series into contributions from respiration and gross primary production, we found the unrestored urban reach to be the most heterotrophic. It removed two times more carbon from the stream to the atmosphere than an unrestored suburban stream that was nutrient impacted and five times more carbon than the restored urban stream. The synoptic sampling revealed that nutrients, light, and hydrodynamic disturbance were the primary controls on carbon fixation and respiration, with fine sediment also exhibiting importance, likely as a vehicle for nutrient transport. Low rates of net carbon removal in the restored stream arose from high light availability resulting in high primary production, combined with low fine sediment availability restricting respiration. Thus, while restoration may have been effective for stream stabilization, it has decreased the functionality of the stream for net carbon removal to the atmosphere. Surprisingly, streambed potential respiration rates were indistinguishable between different geomorphic zones within the streams, suggesting that large-scale factors (i.e., nutrient and fine sediment supply) were more dominant controls than geomorphically controlled local variability.

Arsenic loads in Spearfish Creek, western South Dakota, water years 1989-91

USGS Publications Warehouse

Driscoll, Daniel G.; Hayes, Timothy S.

1995-01-01

Numerous small tributaries on the eastern flank of Spearfish Creek originate within a mineralized area with a long history of gold-mining activity. Some streams draining this area are known to have elevated concentrations of arsenic. One such tributary is Annie Creek, where arsenic concentrations regularly approach the Maximum Contaminant Level of 50 mg/L (micrograms per liter) established by the U.S. Environmental Protection Agency. A site on Annie Creek was proposed for inclusion on the National Priorities List by the Environmental Protection Agency in 1991. This report presents information about arsenic loads and concentrations in Spearfish Creek and its tributaries, including Annie Creek. Stream types were classified according to geologic characteris- tics and in-stream arsenic concentrations. The first type includes streams that lack significant arsenic sources and have low in-stream arsenic concentra- tions. The second type has abundant arsenic sources and high in-stream concentrations. The third type has abundant arsenic sources but only moderate in-stream concentrations. The fourth type is a mixture of the first three types. Annual loads of dissolved arsenic were calculated for two reaches of Spearfish Creek to quantify arsenic loads at selected gaging stations during water years 1989-91. Mass-balance calculations also were performed to estimate arsenic concentrations for ungaged inflows to Spearfish Creek. The drainage area of the upstream reach includes significant mineralized areas, whereas the drainage area of the downstream reach generally is without known arsenic sources. The average load of dissolved arsenic transported from the upstream reach of Spearfish Creek, which is representative of a type 4 stream, was 158 kilograms per year, calculated for station 06430900, Spearfish Creek above Spearfish. Gaged headwater tributaries draining unmineralized areas (type 1) contributed only 16 percent of the arsenic load in 63 percent of the discharge. Annie Creek (type 2), which has the highest measured arsenic concentra- tions in the Spearfish Creek drainage, contributed about 15 percent of the arsenic load in about 2 percent of the discharge of the upstream reach. Squaw Creek, which drains another mineralized area, but has only moderate in-stream concentrations (type 3), contributed 4 percent of the arsenic load in 5 percent of the discharge. Ungaged inflows to the reach contributed the remaining 65 percent of the arsenic load in 30 percent of the discharge. The calculated loads from ungaged inflows include all arsenic contributed by surface- and ground-water sources, as well as any additions of arsenic from dissolution of arsenic-bearing solid phases, or from desorption of arsenic from solid surfaces, within the streambed of the upstream reach. Mass-balance calculations indicate that dissolved arsenic concentrations of the ungaged inflows in the upstream reach averaged about 9 mg/L. In-stream arsenic concentrations of ungaged inflows from the unmineralized western flank of Spearfish Creek probably are generally low (type 1). Thus, in-stream arsenic concentrations for ungaged inflows draining the mineralized eastern flank of Spearfish probably average almost twice that level, or about 18 mg/L. Some ungaged, eastern-flank inflows probably are derived from type 3 drainages, with only moderate arsenic concentrations. If so, other ungaged, eastern-flank inflows could have in-stream arsenic concentrations similar to those of Annie Creek. No significant arsenic sources were apparent in the downstream reach of Spearfish Creek. Over the course of the downstream reach, arsenic concentrations decreased somewhat, probably resulting from dilution, as well as from possible chemical adsorption to sediment surfaces or arsenic-phase precipitation. A decrease in arsenic loads resulted from various diversions from the creek and from the potential chemical removal processes. Because of a large margin of error associated with calculation o

Chemical composition of snow in the east-central Sierra Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, J.C.; Skau, C.M.

1975-01-01

The chemical quality of snowfall in the east-central Sierra Nevada mountains was measured four times at twenty-six sampling points during the period January to April 1975. Mean concentrations (ppM) and total production (lbs/mi2) of eleven major chemical constituents are reported. These values were related to six sampling site characteristics, using simple correlation techniques, to determine the factors which influence the chemical variability of snowfall over this area. Chemical concentrations in the snow here are, apparently, much lower than for precipitation reported in other parts of the country. Nitrogen and phosphorus concentrations, however, are similar to those found in small, easternmore » Sierra streams. The chemical concentrations in snowfall exhibit little variability between sampling sites. This suggests atmospheric concentrations of these constituents are relatively uniform over the area, with localized human activity having, apparently, little influence. The dominant factor causing variation of winter production values (lbs/mi2) between sites is simply the amount of precipitation.« less

Geochemistry of Red Mountain Creek, Colorado, under low-flow conditions, August 2002

USGS Publications Warehouse

Runkel, Robert L.; Kimball, Briant A.; Walton-Day, Katherine; Verplanck, Philip L.

2005-01-01

Red Mountain Creek, an acid mine drainage stream in southwestern Colorado, was the subject of a synoptic study conducted in August 2002. During the synoptic study, a solution containing lithium chloride was injected continuously to allow for the calculation of streamflow using the tracer-dilution method. Synoptic water-quality samples were collected from 48 stream sites and 29 inflow locations along a 5.4-kilometer study reach. Data from the study provide profiles of pH, concentration, and mass load with a high degree of spatial resolution. Despite the presence of 10 circumneutral inflows, pH remained below 3.4 at all stream sites. Concentration profiles indicate that dissolved concentrations of aluminum, cadmium, copper, lead, and zinc exceed chronic aquatic-life standards established by the State of Colorado along the entire study reach. Comparison of total recoverable and dissolved concentrations suggests that most constituents were transported conservatively. Exceptions to this pattern include arsenic, iron, molybdenum, and vanadium, four constituents that were subject to precipitation and(or) sorption reactions as the addition of a circumneutral tributary resulted in a slight increase in instream pH. Evaluation of data from the 29 inflow locations indicates a sharp contrast between the east and west sides of the watershed; inflows from the east side have high constituent concentrations and acidic pH, whereas inflows from the west side have lower concentrations and generally higher pH. Loading profiles, the product of streamflow and concentration, are used to rank potential sources of metals and acidity within the watershed. Four sources account for 83, 72, 70, 69, 64, and 61 percent of the aluminum, iron, arsenic, zinc, copper, and cadmium loading within the study reach, respectively. All four sources appear to be the result of surface inflows that have been affected by mining activities. The relatively small number of major sources and the fact that they are attributable to surface inflows are two factors that may facilitate effective remediation.

Analysis of trace contaminants in hot gas streams using time-weighted average solid-phase microextraction: proof of concept.

PubMed

Woolcock, Patrick J; Koziel, Jacek A; Cai, Lingshuang; Johnston, Patrick A; Brown, Robert C

2013-03-15

Time-weighted average (TWA) passive sampling using solid-phase microextraction (SPME) and gas chromatography was investigated as a new method of collecting, identifying and quantifying contaminants in process gas streams. Unlike previous TWA-SPME techniques using the retracted fiber configuration (fiber within needle) to monitor ambient conditions or relatively stagnant gases, this method was developed for fast-moving process gas streams at temperatures approaching 300 °C. The goal was to develop a consistent and reliable method of analyzing low concentrations of contaminants in hot gas streams without performing time-consuming exhaustive extraction with a slipstream. This work in particular aims to quantify trace tar compounds found in a syngas stream generated from biomass gasification. This paper evaluates the concept of retracted SPME at high temperatures by testing the three essential requirements for TWA passive sampling: (1) zero-sink assumption, (2) consistent and reliable response by the sampling device to changing concentrations, and (3) equal concentrations in the bulk gas stream relative to the face of the fiber syringe opening. Results indicated the method can accurately predict gas stream concentrations at elevated temperatures. Evidence was also discovered to validate the existence of a second boundary layer within the fiber during the adsorption/absorption process. This limits the technique to operating within reasonable mass loadings and loading rates, established by appropriate sampling depths and times for concentrations of interest. A limit of quantification for the benzene model tar system was estimated at 0.02 g m(-3) (8 ppm) with a limit of detection of 0.5 mg m(-3) (200 ppb). Using the appropriate conditions, the technique was applied to a pilot-scale fluidized-bed gasifier to verify its feasibility. Results from this test were in good agreement with literature and prior pilot plant operation, indicating the new method can measure low concentrations of tar in gasification streams. Copyright © 2013 Elsevier B.V. All rights reserved.

Interpolation of Water Quality Along Stream Networks from Synoptic Data

NASA Astrophysics Data System (ADS)

Lyon, S. W.; Seibert, J.; Lembo, A. J.; Walter, M. T.; Gburek, W. J.; Thongs, D.; Schneiderman, E.; Steenhuis, T. S.

2005-12-01

Effective catchment management requires water quality monitoring that identifies major pollutant sources and transport and transformation processes. While traditional monitoring schemes involve regular sampling at fixed locations in the stream, there is an interest synoptic or `snapshot' sampling to quantify water quality throughout a catchment. This type of sampling enables insights to biogeochemical behavior throughout a stream network at low flow conditions. Since baseflow concentrations are temporally persistence, they are indicative of the health of the ecosystems. A major problem with snapshot sampling is the lack of analytical techniques to represent the spatially distributed data in a manner that is 1) easily understood, 2) representative of the stream network, and 3) capable of being used to develop land management scenarios. This study presents a kriging application using the landscape composition of the contributing area along a stream network to define a new distance metric. This allows for locations that are more `similar' to stay spatially close together while less similar locations `move' further apart. We analyze a snapshot sampling campaign consisting of 125 manually collected grab samples during a summer recession flow period in the Townbrook Research Watershed. The watershed is located in the Catskill region of New York State and represents the mixed forest-agriculture land uses of the region. Our initial analysis indicated that stream nutrients (nitrogen and phosphorus) and chemical (major cations and anions) concentrations are controlled by the composition of landscape characteristics (landuse classes and soil types) surrounding the stream. Based on these relationships, an intuitively defined distance metric is developed by combining the traditional distance between observations and the relative difference in composition of contributing area. This metric is used to interpolate between the sampling locations with traditional geostatistic techniques (semivariograms and ordinary kriging). The resulting interpolations provide continuous stream nutrient and chemical concentrations with reduced kriging RMSE (i.e., the interpolation fits the actual data better) performed without path restriction to the stream channel (i.e., the current default for most geostatistical packages) or performed with an in-channel, Euclidean distance metric (i.e., `as the fish swims' distance). In addition to being quantifiably better, the new metric also produces maps of stream concentrations that match expected continuous stream concentrations based on expert knowledge of the watershed. This analysis and its resulting stream concentration maps provide a representation of spatially distributed synoptic data that can be used to quantify water quality for more effective catchment management that focuses on pollutant sources and transport and transformation processes.

Water Stage Forecasting in Tidal streams during High Water Using EEMD

NASA Astrophysics Data System (ADS)

Chen, Yen-Chang; Kao, Su-Pai; Su, Pei-Yi

2017-04-01

There are so many factors may affect the water stages in tidal streams. Not only the ocean wave but also the stream flow affects the water stage in a tidal stream. During high water, two of the most important factors affecting water stages in tidal streams are flood and tide. However the hydrological processes in tidal streams during high water are nonlinear and nonstationary. Generally the conventional methods used for forecasting water stages in tidal streams are very complicated. It explains the accurately forecasting water stages, especially during high water, in tidal streams is always a difficult task. The study makes used of Ensemble Empirical Model Decomposition (EEMD) to analyze the water stages in tidal streams. One of the advantages of the EEMD is it can be used to analyze the nonlinear and nonstationary data. The EEMD divides the water stage into several intrinsic mode functions (IMFs) and a residual; meanwhile, the physical meaning still remains during the process. By comparing the IMF frequency with tidal frequency, it is possible to identify if the IMF is affected by tides. Then the IMFs is separated into two groups, affected by tide or not by tide. The IMFs in each group are assembled to become a factor. Therefore the water stages in tidal streams are only affected by two factors, tidal factor and flood factor. Finally the regression analysis is used to establish the relationship between the factors of the gaging stations in the tidal stream. The available data during 15 typhoon periods of the Tanshui River whose downstream reach is in estuary area is used to illustrate the accuracy and reliability of the proposed method. The results show that the simple but reliable method is capable of forecasting water stages in tidal streams.

Process for recovering organic components from liquid streams

DOEpatents

Blume, Ingo; Baker, Richard W.

1991-01-01

A separation process for recovering organic components from liquid streams. The process is a combination of pervaporation and decantation. In cases where the liquid stream contains the organic to be separated in dissolved form, the pervaporation step is used to concentrate the organic to a point above the solubility limit, so that a two-phase permeate is formed and then decanted. In cases where the liquid stream is a two-phase mixture, the decantation step is performed first, to remove the organic product phase, and the residue from the decanter is then treated by pervaporation. The condensed permeate from the pervaporation unit is sufficiently concentrated in the organic component to be fed back to the decanter. The process can be tailored to produce only two streams: an essentially pure organic product stream suitable for reuse, and a residue stream for discharge or reuse.

Contaminant trends in reservoir sediment cores as records of influent stream quality

USGS Publications Warehouse

Van Metre, P.C.; Mahler, B.J.

2004-01-01

When reconstructing water-quality histories from lake and reservoir cores, it is sometimes assumed that the chemical signatures in the cores reflect historical water quality in the influent streams. To investigate this assumption, concentrations of metals, PAHs, and organochlorine compounds in sediment cores were compared to those associated with an influent-stream suspended sediment for three reservoirs in Fort Worth, TX, and two reservoirs in Boston, MA, U.S.A., and interpreted in light of land-use and regulation histories. In evaluating relations between suspended sediments and cores, three levels of preservation were indicated: (1) influent concentrations and historical trends are preserved in cores (metals at all sites; some organic contaminants at some sites); (2) some loss occurs during transport and initial deposition but relative historical trends are preserved in cores (some organic contaminants at some sites); and (3) neither stream concentrations nor relative historical trends are preserved (dieldrin and p,p???-DDT). The degree of preservation of influent concentration histories varied between lakes, particularly for PAHs. The results support the use of sediment cores to infer streamwater-quality histories for many contaminants but indicate that reservoir-bottom sediment samples might underestimate concentrations of organic contaminants in some streams.

Contamination with bacterial zoonotic pathogen genes in U.S. streams influenced by varying types of animal agriculture

USGS Publications Warehouse

Haack, Sheridan K.; Duris, Joseph W.; Kolpin, Dana W.; Focazio, Michael J.; Meyer, Michael T.; Johnson, Heather E.; Oster, Ryan J.; Foreman, William T.

2016-01-01

Animal waste, stream water, and streambed sediment from 19 small (< 32 km2) watersheds in 12 U.S. states having either no major animal agriculture (control, n = 4), or predominantly beef (n = 4), dairy (n = 3), swine (n = 5), or poultry (n = 3) were tested for: 1) cholesterol, coprostanol, estrone, and fecal indicator bacteria (FIB) concentrations, and 2) shiga-toxin producing and enterotoxigenic Escherichia coli, Salmonella, Campylobacter, and pathogenic and vancomycin-resistant enterococci by polymerase chain reaction (PCR) on enrichments, and/or direct quantitative PCR. Pathogen genes were most frequently detected in dairy wastes, followed by beef, swine and poultry wastes in that order; there was only one detection of an animal-source-specific pathogen gene (stx1) in any water or sediment sample in any control watershed. Post-rainfall pathogen gene numbers in stream water were significantly correlated with FIB, cholesterol and coprostanol concentrations, and were most highly correlated in dairy watershed samples collected from 3 different states. Although collected across multiple states and ecoregions, animal-waste gene profiles were distinctive via discriminant analysis. Stream water gene profiles could also be discriminated by the watershed animal type. Although pathogen genes were not abundant in stream water or streambed samples, PCR on enrichments indicated that many genes were from viable organisms, including several (shiga-toxin producing or enterotoxigenic E. coli, Salmonella, vancomycin-resistant enterococci) that could potentially affect either human or animal health. Pathogen gene numbers and types in stream water samples were influenced most by animal type, by local factors such as whether animals had stream access, and by the amount of local rainfall, and not by studied watershed soil or physical characteristics. Our results indicated that stream water in small agricultural U.S. watersheds was susceptible to pathogen gene inputs under typical agricultural practices and environmental conditions. Pathogen gene profiles may offer the potential to address both source of, and risks associated with, fecal pollution.

Reduced trace element concentrations in fast-growing juvenile Atlantic salmon in natural streams.

PubMed

Ward, Darren M; Nislow, Keith H; Chen, Celia Y; Folt, Carol L

2010-05-01

To assess the effect of rapid individual growth on trace element concentrations in fish, we measured concentrations of seven trace elements (As, Cd, Cs, Hg, Pb, Se, Zn) in stream-dwelling Atlantic salmon (Salmo salar) from 15 sites encompassing a 10-fold range in salmon growth. All salmon were hatched under uniform conditions, released into streams, and sampled approximately 120 days later for trace element analysis. For most elements, element concentrations in salmon tracked those in their prey. Fast-growing salmon had lower concentrations of all elements than slow growers, after accounting for prey concentrations. This pattern held for essential and nonessential elements, as well as elements that accumulate from food and those that can accumulate from water. At the sites with the fastest salmon growth, trace element concentrations in salmon were 37% (Cs) to 86% (Pb) lower than at sites where growth was suppressed. Given that concentrations were generally below levels harmful to salmon and that the pattern was consistent across all elements, we suggest that dilution of elements in larger biomass led to lower concentrations in fast-growing fish. Streams that foster rapid, efficient fish growth may produce fish with lower concentrations of elements potentially toxic for human and wildlife consumers.

Photoelectron spectroscopy of aqueous solutions: Streaming potentials of NaX (X = Cl, Br, and I) solutions and electron binding energies of liquid water and X{sup −}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurahashi, Naoya; Horio, Takuya; Suzuki, Toshinori, E-mail: suzuki@kuchem.kyoto-u.ac.jp

2014-05-07

The streaming potentials of liquid beams of aqueous NaCl, NaBr, and NaI solutions are measured using soft X-ray, He(I), and laser multiphoton ionization photoelectron spectroscopy. Gaseous molecules are ionized in the vicinity of liquid beams and the photoelectron energy shifts are measured as a function of the distance between the ionization point and the liquid beam. The streaming potentials change their polarity with concentration of electrolytes, from which the singular points of concentration eliminating the streaming potentials are determined. The streaming currents measured in air also vanish at these concentrations. The electron binding energies of liquid water and I{sup −},more » Br{sup −}, and Cl{sup −} anions are revisited and determined more accurately than in previous studies.« less

Reactive solute transport in acidic streams

USGS Publications Warehouse

Broshears, R.E.

1996-01-01

Spatial and temporal profiles of Ph and concentrations of toxic metals in streams affected by acid mine drainage are the result of the interplay of physical and biogeochemical processes. This paper describes a reactive solute transport model that provides a physically and thermodynamically quantitative interpretation of these profiles. The model combines a transport module that includes advection-dispersion and transient storage with a geochemical speciation module based on MINTEQA2. Input to the model includes stream hydrologic properties derived from tracer-dilution experiments, headwater and lateral inflow concentrations analyzed in field samples, and a thermodynamic database. Simulations reproduced the general features of steady-state patterns of observed pH and concentrations of aluminum and sulfate in St. Kevin Gulch, an acid mine drainage stream near Leadville, Colorado. These patterns were altered temporarily by injection of sodium carbonate into the stream. A transient simulation reproduced the observed effects of the base injection.

Stream Communities Along a Catchment Land-Use Gradient: Subsidy-Stress Responses to Pastoral Development

NASA Astrophysics Data System (ADS)

Niyogi, Dev K.; Koren, Mark; Arbuckle, Chris J.; Townsend, Colin R.

2007-02-01

When native grassland catchments are converted to pasture, the main effects on stream physicochemistry are usually related to increased nutrient concentrations and fine-sediment input. We predicted that increasing nutrient concentrations would produce a subsidy-stress response (where several ecological metrics first increase and then decrease at higher concentrations) and that increasing sediment cover of the streambed would produce a linear decline in stream health. We predicted that the net effect of agricultural development, estimated as percentage pastoral land cover, would have a nonlinear subsidy-stress or threshold pattern. In our suite of 21 New Zealand streams, epilithic algal biomass and invertebrate density and biomass were higher in catchments with a higher proportion of pastoral land cover, responding mainly to increased nutrient concentration. Invertebrate species richness had a linear, negative relationship with fine-sediment cover but was unrelated to nutrients or pastoral land cover. In accord with our predictions, several invertebrate stream health metrics (Ephemeroptera-Plecoptera-Trichoptera density and richness, New Zealand Macroinvertebrate Community Index, and percent abundance of noninsect taxa) had nonlinear relationships with pastoral land cover and nutrients. Most invertebrate health metrics usually had linear negative relationships with fine-sediment cover. In this region, stream health, as indicated by macroinvertebrates, primarily followed a subsidy-stress pattern with increasing pastoral development; management of these streams should focus on limiting development beyond the point where negative effects are seen.

Analysis of postfire hydrology, water quality, and sediment transport for selected streams in areas of the 2002 Hayman and Hinman fires, Colorado

USGS Publications Warehouse

Stevens, Michael R.

2013-01-01

The U.S. Geological Survey (USGS) began a 5-year study in 2003 that focused on postfire stream-water quality and postfire sediment load in streams within the Hayman and Hinman fire study areas. This report compares water quality of selected streams receiving runoff from unburned areas and burned areas using concentrations and loads, and trend analysis, from seasonal data (approximately April–November) collected 2003–2007 at the Hayman fire study area, and data collected from 1999–2000 (prefire) and 2003 (postfire) at the Hinman fire study area. The water-quality data collected during this study include onsite measurements of streamflow, specific conductance, and turbidity, laboratory-determined pH, and concentrations of major ions, nutrients, organic carbon, trace elements, and suspended sediment. Postfire floods and effects on water quality of streams, lakes and reservoirs, drinking-water treatment, and the comparison of measured concentrations to applicable water quality standards also are discussed. Exceedances of Colorado water-quality standards in streams of both the Hayman and Hinman fire study areas only occurred for concentrations of five trace elements (not all trace-element exceedances occurred in every stream). Selected samples analyzed for total recoverable arsenic (fixed), dissolved copper (acute and chronic), total recoverable iron (chronic), dissolved manganese (acute, chronic, and fixed) and total recoverable mercury (chronic) exceeded Colorado aquatic-life standards.

Ecological characterization of streams, and fish-tissue analysis for mercury and lead at selected locations, Fort Gordon, Georgia, June 1999 to May 2000

USGS Publications Warehouse

Gregory, M. Brian; Stamey, Timothy C.; Wellborn, John B.

2001-01-01

The U.S. Geological Survey, in cooperation with the Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Ga., documented the ecological condition of selected water-bodies on the Fort Gordon military installation from June 1999 to May 2000. This study includes stream-habitat assessments, aquatic invertebrate and fish-community surveys in selected stream reaches, and analyses of mercury and lead concentrations in largemouth bass (Micropterous salmoides) muscle tissue from three impoundments. Assessment surveys indicate lower habitat value scores in some streams draining the more developed areas on Fort Gordon. A small tributary to Butler Creek--which drains parking lots associated with military motor pools and other impervious surfaces--is characterized by moderate levels of bank erosion and excess sediment in the stream channel compared to reference sites. Four other stream reaches are more similar to reference streams in respect to habitat conditions. Invertebrate communities in streams draining these urbanized watersheds are inhabited by 13 to 16 taxa per reach; whereas, 23 and 33 taxa were collected from the two reference stream reaches. Measures of invertebrate abundance, taxa richness, Ephemeroptera, Plecoptera, and Tricoptera Index are lower in streams draining urbanized watersheds. Measures of community similarity also indicate differences between streams draining urbanized areas and reference streams. Streams draining developed areas on Fort Gordon are inhabited by 3 to 10 fish species and included more species regarded as tolerant of degraded water-quality conditions; whereas, the two reference stream reaches support 4 and 10 species, respectively, including one species considered intolerant of degraded water-quality conditions. Mercury was detected in all largemouth bass collected from three impoundments on Fort Gordon. Wet-weight mercury concentrations in fish tissue analyzed from all sites range from 0.08 micrograms per gram to 1.33 micrograms per gram. Median mercury concentrations in fish tissue are 0.83 micrograms per gram at Soil Erosion Lake, 0.72 micrograms per gram at Lower Leitner Lake, and 0.22 micrograms per gram at Gordon Lake. Median mercury concentrations in fish tissue analyzed from Soil Erosion Lake and Lower Leitner Lake are more than two times higher than U.S. Environmental Protection Agency recommendation of 0.3 micrograms per gram for fish consumption. Lead concentrations are below the minimum reporting limit for all specimens analyzed from reservoirs sampled at Fort Gordon.

Sources, transformations, and hydrological processes that control stream nitrate and dissolved organic matter concentrations during snowmelt in an upland forest

Treesearch

Stephen D. Sebestyen; Elizabeth W. Boyer; James B. Shanley; Carol Kendall; Daniel H. Doctor; George R. Aiken; Nobuhito Ohte

2008-01-01

We explored catchment processes that control stream nutrient concentrations at an upland forest in northeastern Vermont, USA, where inputs of nitrogen via atmospheric deposition are among the highest in the nation and affect ecosystem functioning. We traced sources of water, nitrate, and dissolved organic matter (DOM) using stream water samples collected at high...

Mercury cycling in stream ecosystems. 2. Benthic methylmercury production and bed sediment - Pore water partitioning

USGS Publications Warehouse

Marvin-DiPasquale, Mark; Lutz, Michelle A; Brigham, Mark E.; Krabbenhoft, David P.; Aiken, George R.; Orem, William H.; Hall, Britt D.

2009-01-01

Mercury speciation, controls on methylmercury (MeHg) production, and bed sediment−pore water partitioning of total Hg (THg) and MeHg were examined in bed sediment from eight geochemically diverse streams where atmospheric deposition was the predominant Hg input. Across all streams, sediment THg concentrations were best described as a combined function of sediment percent fines (%fines; particles < 63 μm) and organic content. MeHg concentrations were best described as a combined function of organic content and the activity of the Hg(II)-methylating microbial community and were comparable to MeHg concentrations in streams with Hg inputs from industrial and mining sources. Whole sediment tin-reducible inorganic reactive Hg (Hg(II)R) was used as a proxy measure for the Hg(II) pool available for microbial methylation. In conjunction with radiotracer-derived rate constants of 203Hg(II) methylation, Hg(II)R was used to calculate MeHg production potential rates and to explain the spatial variability in MeHg concentration. The %Hg(II)R (of THg) was low (2.1 ± 5.7%) and was inversely related to both microbial sulfate reduction rates and sediment total reduced sulfur concentration. While sediment THg concentrations were higher in urban streams, %MeHg and %Hg(II)R were higher in nonurban streams. Sediment pore water distribution coefficients (log Kd’s) for both THg and MeHg were inversely related to the log-transformed ratio of pore water dissolved organic carbon (DOC) to bed sediment %fines. The stream with the highest drainage basin wetland density also had the highest pore water DOC concentration and the lowest log Kd’s for both THg and MeHg. No significant relationship existed between overlying water MeHg concentrations and those in bed sediment or pore water, suggesting upstream sources of MeHg production may be more important than local streambed production as a driver of water column MeHg concentration in drainage basins that receive Hg inputs primarily from atmospheric sources.

Heat transfer fouling characteristics of microfiltered thin stillage from the dry grind process.

PubMed

Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

2010-08-01

We investigated effects of microfiltration (MF) on heat transfer fouling tendencies of thin stillage. A stainless steel MF membrane (0.1 micron pore size) was used to remove solids from thin stillage. At filtration conditions of 690kPa, the MF process effectively recovered total solids from thin stillage. Thin stillage was concentrated from 7.0% to 22.4% solids with average permeate flux rates of 180+/-30 L/m(2)/h at 75 degrees C. In retentate streams, protein and fat contents were increased from 23.5 and 16.7% db to 27.6 and 31.1% db, respectively, and ash content was reduced from 10.5% to 3.8% db. Removal of solids, protein and fat generated a microfiltration permeate (MFP) that was used as an input stream to the fouling probe system; MFP fouling tendencies were measured. An annular fouling probe was used to measure fouling tendencies of thin stillage from a commercial dry grind facility. When comparing diluted thin stillage (DTS) stream and MFP, a reduction in solids concentration was not the only reason of fouling decrement. Selective removal of protein and fat played an important role in mitigating the fouling. At t=10h, mean fouling rates of MFP were an order of magnitude lower when compared to thin stillage and diluted streams. When maximum probe temperature (200 degrees C) was reached, mean fouling rates for thin stillage, DTS and MFP were 7.1x10(-4), 4.2x10(-4) and 2.6x10(-4) m(2) degrees C/kW/min, respectively. In DTS and MFP, the induction period was prolonged by factors of 4.3 and 9.5, respectively, compared to the induction period for thin stillage fouling. Mean fouling rates were decreased by factors of 2.3 and 23.4 for DTS and MFP, respectively. Fouling of MFP took twice the time to reach a probe temperature of 200 degrees C than did thin stillage (22 h vs 10 h, respectively). A reduction in heat transfer fouling could be achieved by altering process stream composition using microfiltration. Copyright 2010 Elsevier Ltd. All rights reserved.

DOM in stream water and soil solution in two small, bordering catchments in central Sweden

NASA Astrophysics Data System (ADS)

Norström, Sara H.; Bylund, Dan

2013-04-01

Seasonal variations in dissolved organic matter (DOM) and the influence of wood ash application on DOM were studied in two first order streams draining two small, bordering forested catchments. The catchments, 40 and 50 h respectively, were situated in Bispgården (63°07N, 16°70E), central Sweden with forest consisting of mainly 50 to 80 year-old Norway spruce (Picea abies) and Scots pine (Pinus sylvestris). Seasonal variations in the stream water were measured during 2003-2007, and wood ash was applied in one of the catchments in the fall of 2004. In addition to stream water samples, sampling of soil solution in the riparian zone was made in one of the catchments during 2003-2006. The quantity of DOM differed between the streams, but the seasonal patterns for the two streams were correlated during 2003 and 2004. After wood ash treatment, dissolved organic carbon (DOC) increased significantly in the stream draining the treated catchment. 17 different low molecular mass organic acids (LMMOAs) were measured in the stream water during the whole study period. The most abundant LMMOAs were oxalic- and lactic acid, of which peak concentrations of oxalic acid coincided with those of DOC, while no such relation between the concentrations of DOC and lactic acid could be seen in either of the streams. Some of the most common acids in the soil solution, shikimic acid, citric acid and malic acid were rarely found in the stream water and only then in very low concentrations, thus appearing not to have made the transition from soil to stream water in the same manner as oxalic acid. The wood ash application did not affect the total LMMOA concentration and there was no difference during the investigated period. Of the 17 analysed LMMOAs, only malonic acid appeared affected by wood ash application, with a significant increase during both 2005 and 2006.

Water quality of streams draining abandoned and reclaimed mined lands in the Kantishna Hills area, Denali National Park and Preserve, Alaska, 2008–11

USGS Publications Warehouse

Brabets, Timothy P.; Ourso, Robert T.

2013-01-01

The Kantishna Hills are an area of low elevation mountains in the northwest part of Denali National Park and Preserve, Alaska. Streams draining the Kantishna Hills are clearwater streams that support several species of fish and are derived from rain, snowmelt, and subsurface aquifers. However, the water quality of many of these streams has been degraded by mining. Past mining practices generated acid mine drainage and excessive sediment loads that affected water quality and aquatic habitat. Because recovery through natural processes is limited owing to a short growing season, several reclamation projects have been implemented on several streams in the Kantishna Hills region. To assess the current water quality of streams in the Kantishna Hills area and to determine if reclamation efforts have improved water quality, a cooperative study between the U.S. Geological Survey and the National Park Service was undertaken during 2008-11. High levels of turbidity, an indicator of high concentrations of suspended sediment, were documented in water-quality data collected in the mid-1980s when mining was active. Mining ceased in 1985 and water-quality data collected during this study indicate that levels of turbidity have declined significantly. Turbidity levels generally were less than 2 Formazin Nephelometric Units and suspended sediment concentrations generally were less than 1 milligram per liter during the current study. Daily turbidity data at Rock Creek, an unmined stream, and at Caribou Creek, a mined stream, documented nearly identical patterns of turbidity in 2009, indicating that reclamation as well as natural revegetation in mined streams has improved water quality. Specific conductance and concentrations of dissolved solids and major ions were highest from streams that had been mined. Most of these streams flow into Moose Creek, which functions as an integrator stream, and dilutes the specific conductance and ion concentrations. Calcium and magnesium are the dominant cations, and bicarbonate and sulfate are the dominant anions. Water samples indicate that the water from Rock Creek, Moose Creek, Slate Creek, and Eldorado Creek is a calcium bicarbonate-type water. The remaining sites are a calcium sulfate type water. U.S. Environmental Protection Agency guidelines for arsenic and antimony in drinking water were exceeded in water at Slate Creek and Eureka Creek. Concentrations of arsenic, cadmium, chromium, copper, lead, nickel, and zinc in streambed sediments at many sites exceed sediment quality guideline thresholds that could be toxic to aquatic life. However, assessment of these concentrations, along with the level of organic carbon detected in the sediment, indicate that only concentrations of arsenic and chromium may be toxic to aquatic life at many sites. In 2008 and 2009, 104 macroinvertebrate taxa and 164 algae taxa were identified from samples collected from seven sites. Of the macroinvertebrates, 86 percent were insects and most of the algae consisted of diatoms. Based on the National Community Index, Rock Creek, a reference site, and Caribou Creek, and a mined stream that had undergone some reclamation, exhibited the best overall stream conditions; whereas Slate Creek and Friday Creek, two small streams that were mined extensively, exhibited the worst stream conditions. A non-metric multi-dimensional scaling analysis of the macroinvertebrate and algae data showed a distinct grouping between the 2008 and 2009 samples, likely because of differences between a wet, cool summer in 2008 and a dry, warm summer in 2009.

Diel biogeochemical processes and their effect on the aqueous chemistry of streams: A review

USGS Publications Warehouse

Nimick, David A.; Gammons, Christopher H.; Parker, Stephen R.

2011-01-01

This review summarizes biogeochemical processes that operate on diel, or 24-h, time scales in streams and the changes in aqueous chemistry that are associated with these processes. Some biogeochemical processes, such as those producing diel cycles of dissolved O2 and pH, were the first to be studied, whereas processes producing diel concentration cycles of a broader spectrum of chemical species including dissolved gases, dissolved inorganic and organic carbon, trace elements, nutrients, stable isotopes, and suspended particles have received attention only more recently. Diel biogeochemical cycles are interrelated because the cyclical variations produced by one biogeochemical process commonly affect another. Thus, understanding biogeochemical cycling is essential not only for guiding collection and interpretation of water-quality data but also for geochemical and ecological studies of streams. Expanded knowledge of diel biogeochemical cycling will improve understanding of how natural aquatic environments function and thus lead to better predictions of how stream ecosystems might react to changing conditions of contaminant loading, eutrophication, climate change, drought, industrialization, development, and other factors.

Chlorinated pesticides in stream sediments from organic, integrated and conventional farms.

PubMed

Shahpoury, Pourya; Hageman, Kimberly J; Matthaei, Christoph D; Magbanua, Francis S

2013-10-01

To determine if current sheep/beef farming practices affect pesticide residues in streams, current-use and legacy chlorinated pesticides were quantified in 100 sediment samples from 15 streams on the South Island of New Zealand. The study involved five blocks of three neighboring farms, with each block containing farms managed by organic, integrated and conventional farming practices. Significantly higher concentrations of dieldrin, ∑ endosulfans, ∑ current-use pesticides, and ∑ chlorinated pesticides were measured in sediments from conventional farms compared to organic and integrated farms. However, streams in the latter two farming categories were not pesticide-free and sometimes contained relatively high concentrations of legacy pesticides. Comparison of measured pesticide concentrations with sediment quality guidelines showed that, regardless of farming practice, mean pesticide concentrations were below the recommended toxicity thresholds. However, up to 23% of individual samples contained chlorpyrifos, endosulfan sulfate, ∑ DDT, dieldrin, or ∑ chlordane concentrations above these thresholds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Response of an algal assemblage to nutrient enrichment and shading in a Hawaiian stream

USGS Publications Warehouse

Stephens, S.H.; Brasher, A.M.D.; Smith, C.M.

2012-01-01

To investigate the effects of nitrate enrichment, phosphate enrichment, and light availability on benthic algae, nutrient-diffusing clay flowerpots were colonized with algae at two sites in a Hawaiian stream during spring and autumn 2002 using a randomized factorial design. The algal assemblage that developed under the experimental conditions was investigated by determining biomass (ash-free dry mass and chlorophyll a concentrations) and composition of the diatom assemblage. In situ pulse amplitude-modulated fluorometry was also used to model photosynthetic rate of the algal assemblage. Algal biomass and maximum photosynthetic rate were significantly higher at the unshaded site than at the shaded site. These parameters were higher at the unshaded site with either nitrate, or to a lesser degree, nitrate plus phosphate enrichment. Analysis of similarity of diatom assemblages showed significant differences between shaded and unshaded sites, as well as between spring and autumn experiments, but not between nutrient treatments. However, several individual species of diatoms responded significantly to nitrate enrichment. These results demonstrate that light availability (shaded vs. unshaded) is the primary limiting factor to algal growth in this stream, with nitrogen as a secondary limiting factor. ?? 2011 Springer Science+Business Media B.V.

Background hydrologic information in potential lignite mining areas in north-central Mississippi, August 1984

USGS Publications Warehouse

Kalkhoff, S.J.

1985-01-01

The U.S. Geological Survey, in cooperation with the Mississippi Department of Natural Resources, Bureau of Geology, is conducting a hydrologic data collection program in potential lignite-producing areas in Mississippi. During the last two weeks of August 1984, hydrologic data were collected at 15 stream sites that drain potential lignite mining areas in Lafayette, Calhoun, and Yalobusha Counties. Main channel widths ranged from approximately 60 feet at three streams (Coon Creek near Toccopula, Muckaloon Creek near Tula, and Hurricane Creek near Velma) to approximately 120 feet at two streams (Potlockney Creek near Tula, and Savannah Creek near Bruce). Maximum water depths ranged from less than 1.0 foot at most streams to over 5.0 feet at sites on Potlockney Creek near Tula and McGill Creek near Sarepta. Stream discharge ranged from 0.32 cubic feet per second in Persimmon Creek near Bruce to 18.5 cubic feet per second in Puskus Creek near Etta. The specific conductance of stream water ranged from 25 to 160 microsiemens and dissolved solids concentrations ranged from 22 to 91 mg/L (milligrams per liter). Most major ion concentrations were less than 10 mg/L with the exception of calcium (11 mg/L), sodium (12 mg/L) and sulfate (18 mg/L) in the water of Persimmon Creek near Bruce. Dissolved oxygen concentrations were greater than 5.0 mg/L at all but one site. Turbidity values were generally less than 50 units. Nitrate plus nitrite concentrations were equal to or less than 0.10 mg/L in all streams except in Potlockney Creek near Tula where the concentration was 0.11 mg/L. Copper and selenium concentrations in the water at all sampling sites ranged from below the detection limits (1 microgram/g) to 4 micrograms/g (micrograms per gram) and mercury concentrations in bottom material samples ranged from less than 0.01 microgram/g to 0.15 microgram/g. (USGS)

Sources and preparation of data for assessing trends in concentrations of pesticides in streams of the United States, 1992–2010

USGS Publications Warehouse

Martin, Jeffrey D.; Eberle, Michael; Nakagaki, Naomi

2011-01-01

This report updates a previously published water-quality dataset of 44 commonly used pesticides and 8 pesticide degradates suitable for a national assessment of trends in pesticide concentrations in streams of the United States. Water-quality samples collected from January 1992 through September 2010 at stream-water sites of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program and the National Stream Quality Accounting Network (NASQAN) were compiled, reviewed, selected, and prepared for trend analysis. The principal steps in data review for trend analysis were to (1) identify analytical schedule, (2) verify sample-level coding, (3) exclude inappropriate samples or results, (4) review pesticide detections per sample, (5) review high pesticide concentrations, and (6) review the spatial and temporal extent of NAWQA pesticide data and selection of analytical methods for trend analysis. The principal steps in data preparation for trend analysis were to (1) select stream-water sites for trend analysis, (2) round concentrations to a consistent level of precision for the concentration range, (3) identify routine reporting levels used to report nondetections unaffected by matrix interference, (4) reassign the concentration value for routine nondetections to the maximum value of the long-term method detection level (maxLT-MDL), (5) adjust concentrations to compensate for temporal changes in bias of recovery of the gas chromatography/mass spectrometry (GCMS) analytical method, and (6) identify samples considered inappropriate for trend analysis. Samples analyzed at the USGS National Water Quality Laboratory (NWQL) by the GCMS analytical method were the most extensive in time and space and, consequently, were selected for trend analysis. Stream-water sites with 3 or more water years of data with six or more samples per year were selected for pesticide trend analysis. The selection criteria described in the report produced a dataset of 21,988 pesticide samples at 212 stream-water sites. Only 21,144 pesticide samples, however, are considered appropriate for trend analysis.

Variation in responses to spawning Pacific salmon among three south-eastern Alaska streams

USGS Publications Warehouse

Chaloner, D.T.; Lamberti, G.A.; Merritt, R.W.; Mitchell, N.L.; Ostrom, P.H.; Wipfli, M.S.

2004-01-01

1. Pacific salmon are thought to stimulate the productivity of the fresh waters in which they spawn by fertilising them with marine-derived nutrients (MDN). We compared the influence of salmon spawners on surface streamwater chemistry and benthic biota among three southeastern Alaska streams. Within each stream, reaches up- and downstream of barriers to salmon migration were sampled during or soon after spawners entered the streams. 2. Within streams, concentrations of dissolved ammonium and soluble reactive phosphorus (SRP), abundance of epilithon (chlorophyll a and ash-free dry mass) and biomass of chironomids were significantly higher in reaches with salmon spawners. In contrast, biomass of the mayflies Epeorus spp. and Rhithrogena spp. was significantly higher in reaches lacking spawners. 3. Among streams, significant differences were found in concentrations of dissolved ammonium, dissolved organic carbon, nitrate and SRP, abundance of epilithon, and the biomass of chironomids and Rhithrogena. These differences did not appear to reflect differences among streams in spawner density, nor the changes in water chemistry resulting from salmon spawners. 4. Our results suggest that the 'enrichment' effect of salmon spawners (e.g. increased streamwater nutrient concentrations) was balanced by other concurrent effects of spawners on streams (e.g. sediment disturbance). Furthermore, the collective effect of spawners on lotic ecosystems is likely to be constrained by conditions unique to individual streams, such as temperature, background water chemistry and light attenuation.

Contribution of hydroxylated atrazine degradation products to the total atrazine load in midwestern streams

USGS Publications Warehouse

Lerch, R.N.; Blanchard, P.E.; Thurman, E.M.

1998-01-01

The contribution of hydroxylated atrazine degradation products (HADPs) to the total atrazine load (i.e., atrazine plus stable metabolites)in streams needs to be determined in order to fully assess the impact of atrazine contamination on stream ecosystems and human health. The objectives of this study were (1) to determine the contribution of HADPs to the total atrazine load in streams of nine midwestern states and (2) to discuss the mechanisms controlling the concentrations of HADPs in streams. Stream samples were collected from 95 streams in northern Missouri at preplant and postplant of 1994 and 1995, and an additional 46 streams were sampled in eight midwestern states at postplant of 1995. Samples were analyzed for atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), and three HADPs. Overall, HADP prevalence (i.e., frequency of detection) ranged from 87 to 100% for hydroxyatrazine (HA), 0 to 58% for deethylhydroxyatrazine (DEHA), and 0% for deisopropylhydroxyatrazine (DIHA) with method detection limits of 0.04-0.10 ??g L-1. Atrazine metabolites accounted for nearly 60% of the atrazine load in northern Missouri streams at preplant, with HA the predominant metabolite present. Data presented in this study and a continuous monitoring study are used to support the hypothesis that a combination of desorption from stream sediments and dissolved-phase transport control HADP concentrations in streams.The contribution of hydroxylated atrazine degradation products (HADPs) to the total atrazine load (i.e., atrazine plus stable metabolites) in streams needs to be determined in order to fully assess the impact of atrazine contamination on stream ecosystems and human health. The objectives of this study were (1) to determine the contribution of HADPs to the total atrazine load in streams of nine midwestern states and (2) to discuss the mechanisms controlling the concentrations of HADPs in streams. Stream samples were collected from 95 streams in northern Missouri at preplant and postplant of 1994 and 1995, and an additional 46 streams were sampled in eight midwestern states at postplant of 1995. Samples were analyzed for atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), and three HADPs. Overall, HADP prevalence (i.e., frequency of detection) ranged from 87 to 100% for hydroxyatrazine (HA), 0 to 58% for deethylhydroxyatrazine (DEHA), and 0% for deisopropylhydroxyatrazine (DIHA) with method detection limits of 0.04-0.10 ??g L-1. Atrazine metabolites accounted for nearly 60% of the atrazine load in northern Missouri streams at preplant, with HA the predominant metabolite present. Data presented in this study and a continuous monitoring study are used to support the hypothesis that a combination of desorption from stream sediments and dissolved-phase transport control HADP concentrations in streams.

Temporal trends of bulk precipitation and stream water chemistry (1977-1997) in a small forested area, Krusne hory, northern Bohemia, Czech Republic

USGS Publications Warehouse

Peters, N.E.; Cerny, J.; Havel, M.; Krejci, R.

1999-01-01

The Krusne hory (Erzgebirge or Ore Mountains) has been heavily affected by high atmospheric pollutant deposition caused by fossil fuel combustion in an adjacent Tertiary coal basin. Long-term routine sampling of bulk precipitation (1977-1996) and stream water (1977-1998) in a forested area on the south-eastern slope of the mountains were used to evaluate trends and patterns in solute concentration and flux with respect to controlling processes. From 1977 to 1996, the annual volume-weighted Ca2+ and SO42- concentrations decreased in bulk precipitation. However, after 1989, when a pronounced and continuous decrease occurred in coal production, annual volume-weighted concentrations decreased for most solutes, except H+. The concentration decreases were marked, with 1996 levels at or below 50% of those in 1989. The lack of a trend in H+ is attributed to similar decreases in both acid anions and neutralizing base cations. Stream water concentrations of most solutes, i.e. H+, Ca2+, Mg2+, SO42- and NO3-, were highest at the onset of sampling in 1977, decreased markedly from 1977 to 1983 and decreased more gradually from 1983 to 1998. The spruce forest die-back and removal reduced dry deposition of these solutes by reducing the filtering action, which was provided by the forest canopy. A notable decrease in stream water Ca2+ concentrations occurred after 1995 and may be due to the depletion of Ca2+, which was provided by catchment liming in 1986, 1988 and 1989. Solute flux trends in bulk atmospheric deposition and stream water generally were not significant and the lack of trend is attributed to the large interannual variability in precipitation quantity and runoff, respectively. All solutes except Na+ varied seasonally. The average seasonal concentrations varied between the solutes, but for most solutes were highest in winter and spring and lowest in summer, correlating with the seasonal trend and runoff. For Ca2+, Mg2+ and SO42-, the concentration minimum occurs in September and the maximum occurs in February or March, correlating with the seasonal baseflow. These solutes are primarily controlled by the contribution of soil water and groundwater to stream flow. During snowmelt, the meltwater generally causes concentrations to decrease as soil water and groundwater are diluted. For NO3, average minimum concentrations occur in August at the end of the growing season concurrent with the lowest stream flow, and the maximum occurs in February and March with high stream flow during snowmelt. Seasonal stream water NO3- concentration variations are large compared with the long-term decrease.The Krusne hory (Erzgebirge or Ore Mountains) has been heavily affected by high atmospheric pollutant deposition caused by fossil fuel combustion in an adjacent Tertiary coal basin. Long-term routine sampling of bulk precipitation (1977-1996) and stream water (1977-1998) in a forested area on the south-eastern slope of the mountains were used to evaluate trends and patterns in solute concentration and flux with respect to controlling processes. From 1977 to 1996, the annual volume-weighted Ca2+ and SO42- concentrations decreased in bulk precipitation. However, after 1989, when a pronounced and continuous decrease occurred in coal production, annual volume-weighted concentrations decreased for most solutes, except H+. The concentration decreases were marked, with 1996 levels at or below 50% of those in 1989. The lack of a trend in H+ is attributed to similar decreases in both acid anions and neutralizing base cations. Stream water concentrations of most solutes, i.e. H+, Ca2+, Mg2+, SO42- and NO3-, were highest at the onset of sampling in 1977, decreased markedly from 1977 to 1983 and decreased more gradually from 1983 to 1998. The spruce forest die-back and removal reduced dry deposition of these solutes by reducing the filtering action, which was provided by the forest canopy. A notable decrease in stream water Ca2+ concentrations occurred after 1995 an

Quantifying nutrient sources in an upland catchment using multiple chemical and isotopic tracers

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Boyer, E. W.; Shanley, J. B.; Doctor, D. H.; Kendall, C.; Aiken, G. R.

2006-12-01

To explore processes that control the temporal variation of nutrients in surface waters, we measured multiple environmental tracers at the Sleepers River Research Watershed, an upland catchment in northeastern Vermont, USA. Using a set of high-frequency stream water samples, we quantified the variation of nutrients over a range of stream flow conditions with chemical and isotopic tracers of water, nitrate, and dissolved organic carbon (DOC). Stream water concentrations of nitrogen (predominantly in the forms of nitrate and dissolved organic nitrogen) and DOC reflected mixing of water contributed from distinct sources in the forested landscape. Water isotopic signatures and end-member mixing analysis revealed when solutes entered the stream from these sources and that the sources were linked to the stream by preferential shallow subsurface and overland flow paths. Results from the tracers indicated that freshly-leached, terrestrial organic matter was the overwhelming source of high DOC concentrations in stream water. In contrast, in this region where atmospheric nitrogen deposition is chronically elevated, the highest concentrations of stream nitrate were attributable to atmospheric sources that were transported via melting snow and rain fall. These findings are consistent with a conceptual model of the landscape in which coupled hydrological and biogeochemical processes interact to control stream solute variability over time.

Urbanization influences on aquatic communities in northeastern Illinois streams

USGS Publications Warehouse

Fitzpatrick, F.A.; Harris, M.A.; Arnold, T.L.; Richards, K.D.

2004-01-01

Biotic indices and sediment trace element concentrations for 43 streams in northeastern Illinois (Chicago area) from the 1980s and 1990s were examined along an agricultural to urban land cover gradient to explore the relations among biotic integrity, sediment chemistry, and urbanization. The Illinois fish Alternative Index of Biotic Integrity (AIBI) ranged from poor to excellent in agricultural/rural streams, but streams with more than 10 percent watershed urban land (about 500 people/mi2) had fair or poor index scores. A macroinvertebrate index (MBI) showed similar trends. A qualitative habitat index (PIBI) did not correlate to either urban indicator. The AIBI and MBI correlated with urban associated sediment trace element concentrations. Elevated copper concentrations in sediment occurred in streams with greater than 40 percent watershed urban land. The number of intolerant fish species and modified index of biotic integrity scores increased in some rural, urbanizing, and urban streams from the 1980s to 1990s, with the largest increases occurring in rural streams with loamy/sandy surficial deposits. However, smaller increases also occurred in urban streams with clayey surficial deposits and over 50 percent watershed urban land. These data illustrate the potentially complex spatial and temporal relations among biotic integrity, sediment chemistry, watershed urban land, population density, and regional and local geologic setting.

Assessing the influence of multiple stressors on stream diatom metrics in the upper Midwest, USA

USGS Publications Warehouse

Munn, Mark D.; Waite, Ian R.; Konrad, Christopher P.

2018-01-01

Water resource managers face increasing challenges in identifying what physical and chemical stressors are responsible for the alteration of biological conditions in streams. The objective of this study was to assess the comparative influence of multiple stressors on benthic diatoms at 98 sites that spanned a range of stressors in an agriculturally dominated region in the upper Midwest, USA. The primary stressors of interest included: nutrients, herbicides and fungicides, sediment, and streamflow; although the influence of physical habitat was incorporated in the assessment. Boosted Regression Tree was used to examine both the sensitivity of various diatom metrics and the relative importance of the primary stressors. Percent Sensitive Taxa, percent Highly Motile Taxa, and percent High Phosphorus Taxa had the strongest response to stressors. Habitat and total phosphorous were the most common discriminators of diatom metrics, with herbicides as secondary factors. A Classification and Regression Tree (CART) model was used to examine conditional relations among stressors and indicated that fine-grain streams had a lower percentage of Sensitive Taxa than coarse-grain streams, with Sensitive Taxa decreasing further with increased water temperature (>30 °C) and triazine concentrations (>1500 ng/L). In contrast, streams dominated by coarse-grain substrate contained a higher percentage of Sensitive Taxa, with relative abundance increasing with lower water temperatures (<29 °C) and shallower water depth (<0.3 m). Quantile regression indicated that maximum water temperature appears to be a major limiting factor in Midwest streams; whereas both total phosphorus and percent fines showed a slight subsidy-stress response. While using benthic algae for assessing stream quality can be challenging, field-based studies can elucidate stressor effects and interactions when the response variables are appropriate, sufficient stressor resolution is achieved, and the number and type of sites represent a gradient of stressor conditions and at least a quasi-factorial design.

Stream-aquifer interactions in the Straight River area, Becker and Hubbard counties, Minnesota

USGS Publications Warehouse

Stark, J.R.; Armstrong, David S.; Zwilling, Daniel R.

1994-01-01

Daily fluctuations of stream temperature are as great as 15 degrees Celsius during the summer, primarily in response to changes in air temperature. Ground-water discharge to the Straight River decreases stream temperature during the summer. Results of simulations from a stream-temperature model indicate that daily changes in stream temperature are strongly influenced by solar radiation, wind speed, stream depth, and ground-water inflow. Results of simulations from ground-water-flow and stream-temperature models developed for the investigation indicate a significant decrease in ground-water flow could result from ground-water withdrawal at rates similar to those measured during 1988. This reduction in discharge to the stream could result in an increase in stream temperature of 0.5 to 1.5 degrees Celsius. Nitrate concentrations in shallow wells screened at the water table, in some areas, are locally greater than the limit set by the Minnesota Pollution Control Agency. Nitrate concentrations in water from deeper wells and in the stream are low, generally less than 1.0 milligram per liter.

Characterization of Water Quality in Unmonitored Streams in the Mississippi Alluvial Plain, Northwestern Mississippi, May-June 2006

USGS Publications Warehouse

Bryson, Jeannie R.; Coupe, Richard H.; Manning, Michael A.

2007-01-01

The Mississippi Department of Environmental Quality is required to develop restoration and remediation plans for water bodies not meeting their designated uses, as stated in the U.S. Environmental Protection Agency's Clean Water Act section 303(d). The majority of streams in northwestern Mississippi are on the 303(d) list of water-quality limited waters. Agricultural effects on streams in northwestern Mississippi have reduced the number of unimpaired streams (reference streams) for water-quality comparisons. As part of an effort to develop an index to assess impairment, the U.S. Geological Survey collected water samples from 52 stream sites on the 303(d) list during May-June 2006, and analyzed the samples for nutrients and chlorophyll. The data were analyzed by trophic group as determined by total nitrogen concentrations. Seven constituents (nitrite plus nitrate, total Kjeldhal nitrogen, total phosphorus, orthophosphorus, total organic carbon, chlorophyll a, and pheophytina) and four physical property measurements (specific conductance, pH, turbidity, and dissolved oxygen) were determined to be significantly different (p < 0.05) between trophic groups. Total Kjeldhal nitrogen, turbidity, and dissolved oxygen were used as indicators of stream productivity with which to infer stream health. Streams having high total Kjeldhal nitrogen values and high turbidity values along with low dissolved oxygen concentrations were typically eutrophic abundant in nutrients), whereas streams having low total Kjeldhal nitrogen values and low turbidity values along with high dissolved oxygen concentrations were typically oligotrophic (deficient in nutrients).

Effects of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) on pH, net oxygen production, and respiration by algae

USGS Publications Warehouse

Scholefield, Ronald J.; Fredricks, Kim T.; Slaght, Karen S.; Seelye, James G.

1999-01-01

The lampricide 3-trifluoromethyl-4-nitrophenol (TFM) has been used in the United States and Canada for more than 35 years to control larval sea lampreys (Petromyzon marinus) in tributaries of the Great Lakes. Occasionally, during stream treatments with TFM, nontarget-fish mortality reaches unacceptable levels. These losses could be due to the presence of sensitive fish species, excess TFM, or a combination of factors that influence the toxicity of TFM, such as delays in daily stream reaeration by algae resulting in extended periods of low pH and low dissolved oxygen (DO). We determined the effects of a broad range of TFM concentrations on net DO production and respiration by two species of algae, in two culture media (high alkalinity and low alkalinity). The pH and DO in cultures of Chlorella pyrenoidosa and Selenastrum capricornutum were recorded at time zero and again after a 9-h exposure to TFM under either lighted or dark conditions. Algal cultures exposed to TFM concentrations typical of those used to control sea lampreys in streams showed only small changes in pH (<0.1) and small reductions in DO (about 8% in lighted conditions and 11% in dark conditions). Changes in pH and DO of this magnitude probably do not change the efficacy of TFM or cause nontarget fish mortality if algae are the predominant photosynthetic organisms in the stream.

Wet and Dry Atmospheric Mercury Deposition Accumulates in Watersheds of the Northeastern United States

NASA Astrophysics Data System (ADS)

Boyer, E. W.; Grant, C.; Grimm, J.; Drohan, P. J.; Bennett, J.; Lawler, D.

2013-12-01

Mercury emissions to the atmosphere from coal-fired power plants and other sources such as waste incineration can be deposited to landscapes in precipitation and in dry fallout. Some mercury reaches watersheds and streams, where it can accumulate in sediments and biota. Human exposure to mercury occurs primarily through fish consumption, and currently mercury fish eating advisories are in place for many of the streams and lakes in the state. Here, we explored mercury in air, soils, water, and biota. To quantify atmospheric mercury deposition, we measured both wet and dry mercury deposition at over 10 locations in Pennsylvania, from which we present variation in mercury deposition and initial assessments of factors affecting the patterns. Further, we simulated mercury deposition at unmonitored locations in Pennsylvania and the northeastern United States over space and time with a high-resolution modeling technique that reflects storm tracks and air flow patterns. To consider mercury accumulation in watersheds, we collected data on soil mercury concentrations in a set of soil samples, and collected baseline data on mercury in streams draining 35 forested watersheds across Pennsylvania, spanning gradients of atmospheric deposition, climate and geology. Mercury concentrations were measured in stream water under base-flow conditions, in streambed sediments, aquatic mosses, and in fish tissues from brook trout. Results indicate that wet and dry atmospheric deposition is a primary source of mercury that is accumulating in watersheds of Pennsylvania and the northeastern United States.

Impact of stream geomorphology on greenhouse gas concentration in a New York mountain stream

Treesearch

Philippe Vidon; Satish Serchan

2016-01-01

As increased greenhouse gas concentrations (GHG: N2O, CO2, CH4) in our atmosphere remain a major concern, better quantifying GHG fluxes from natural systems is essential. In this study, we investigate GHG concentrations in saturated riparian sediments (dry, wet, mucky), streambed hyporheic zone...

A Study on the Land Use Characteristics of Urban Medium and Small stream Depending on the Width of stream

NASA Astrophysics Data System (ADS)

Seok, Song Young; Ho, Song Yang; Ho, Lee Jung; Moo Jong, Park

2015-04-01

Due to the increase of impervious layers caused by increased rainfall and urbanization which were brought about by the climate change after the late 1990s, the flood damage in urban watersheds is rising. The recent flood damage is occurring in medium and small stream rather than in large stream. Particularly, in medium stream which pass the cities, sudden flood occurs due to the short concentration of rainfall and urban areas suffer large damage, even though the flood damage is small, since residential areas and social infrastructures are concentrated. In spite of the importance of medium and small stream to pass the cities, there is no certain standard for classification of natural or urban stream and existing studies are mostly focused on the impervious area among the land use characteristics of watersheds. Most of existing river studies are based on the watershed scale, but in most urban watersheds where stream pass, urban areas are concentrated in the confluence, so urban areas only occupy less than 10% of the whole watershed and there is a high uncertainty in the classification of urban areas, based the watershed of stream. This study aims to suggest a classification standard of medium and small stream between local stream and small stream where suffer flood damage. According to the classified medium and small stream, this study analyzed the stream area to the stream width and distance using Arcgis Buffer tool, based on the stream line, not the existing watershed scale. This study then chose urban watersheds by analyzing the river area at certain intervals from the center of the chosen medium and small stream, in different ways. Among the land use characteristics in urban areas, the impervious area was applied to the selection standard of urban watersheds and the characteristics of urban watersheds were presented by calculating the ratio of the stream area to the impervious area using the Buffer tool. Acknowledgement "This research was supported by a grant [NEMA-NH-2011-45] from the Natural Hazard Mitigation Research Group, National Emergency Management Agency of Korea." Keywords: land use, urban watershed, medium and smaill stream, impervious area

Water Quality, Physical Habitat, and Biology of the Kijik River Basin, Lake Clark National Park and Preserve, Alaska, 2004-2005

USGS Publications Warehouse

Brabets, Timothy P.; Ourso, Robert T.

2006-01-01

The U.S. Geological Survey and the National Park Service conducted a water-quality investigation of the Kijik River Basin in Lake Clark National Park and Preserve from June 2004 to March 2005. The Kijik River Basin was studied because it has a productive sockeye salmon run that is important to the larger Kvichak River watershed. Water-quality, physical habitat, and biological characteristics were assessed. Water type throughout the Kijik River Basin is calcium bicarbonate although Little Kijik River above Kijik Lake does have slightly higher concentrations of sulfate and chloride. Alkalinity concentrations are generally less than 28 milligrams per liter, indicating a low buffering capacity of these waters. Lachbuna Lake traps much of the suspended sediment from the glacier streams in the headwaters of the basin as evidenced by low secchi-disc transparency of 1 to 2 meters and low suspended sediment concentrations in the Kijik River downstream from the lake. Kijik Lake is a fed by clearwater streams and has secchi-disc readings ranging from 11 to 15 meters. Streambed sediments collected from four surface sites analyzed for trace elements indicated that arsenic concentrations at all sites were above proposed guidelines. However, arsenic concentrations are due to the local geology, not anthropogenic factors. Benthic macroinvertebrate qualitative multi-habitat samples collected from two sites on the Little Kijik River and two sites on the main stem of the Kijik River indicated a total of 69 taxa present among the four sites. The class Insecta, made up the largest percentage of macroinvertebrates, totaling 70 percent of the families found. The insects were comprised of four orders; Diptera (flies and midges), Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies). One-hundred twenty-two species of periphytic algae were identified in qualitative multi-habitat samples collected at the four stream sites. Eight species of non-motile, diatoms were collected from all four stream sites suggesting that the areas from which they were collected are relatively stable and unaffected by sedimentation.

Primary weathering rates, water transit times and concentration-discharge relations: A theoretical analysis for the critical zone

NASA Astrophysics Data System (ADS)

Ameli, Ali; Erlandsson, Martin; Beven, Keith; Creed, Irena; McDonnell, Jeffrey; Bishop, Kevin

2017-04-01

The permeability architecture of the critical zone exerts a major influence on the hydrogeochemistry of the critical zone. Water flowpath dynamics drive the spatio-temporal pattern of geochemical evolution and resulting streamflow concentration-discharge (C-Q) relation, but these flowpaths are complex and difficult to map quantitatively. Here, we couple a new integrated flow and particle tracking transport model with a general reversible Transition-State-Theory style dissolution rate-law to explore theoretically how C-Q relations and concentration in the critical zone respond to decline in saturated hydraulic conductivity (Ks) with soil depth. We do this for a range of flow rates and mineral reaction kinetics. Our results show that for minerals with a high ratio of equilibrium concentration to intrinsic weathering rate, vertical heterogeneity in Ks enhances the gradient of weathering-derived solute concentration in the critical zone and strengthens the inverse stream C-Q relation. As the ratio of equilibrium concentration to intrinsic weathering rate decreases, the spatial distribution of concentration in the critical zone becomes more uniform for a wide range of flow rates, and stream C-Q relation approaches chemostatic behaviour, regardless of the degree of vertical heterogeneity in Ks. These findings suggest that the transport-controlled mechanisms in the hillslope can lead to chemostatic C-Q relations in the stream while the hillslope surface reaction-controlled mechanisms are associated with an inverse stream C-Q relation. In addition, as the ratio of equilibrium concentration to intrinsic weathering rate decreases, the concentration in the critical zone and stream become less dependent on groundwater age (or transit time)

Calculating discharge of phosphorus and nitrogen with groundwater base flow to a small urban stream reach

NASA Astrophysics Data System (ADS)

Fitzgerald, Alex; Roy, James W.; Smith, James E.

2015-09-01

Elevated levels of nutrients, especially phosphorus, in urban streams can lead to eutrophication and general degradation of stream water quality. Contributions of phosphorus from groundwater have typically been assumed minor, though elevated concentrations have been associated with riparian areas and urban settings. The objective of this study was to investigate the importance of groundwater as a pathway for phosphorus and nitrogen input to a gaining urban stream. The stream at the 28-m study reach was 3-5 m wide and straight, flowing generally eastward, with a relatively smooth bottom of predominantly sand, with some areas of finer sediments and a few boulders. Temperature-based methods were used to estimate the groundwater flux distribution. Detailed concentration distributions in discharging groundwater were mapped using in-stream piezometers and diffusion-based peepers, and showed elevated levels of soluble reactive phosphorus (SRP) and ammonium compared to the stream (while nitrate levels were lower), especially along the south bank, where groundwater fluxes were lower and geochemically reducing conditions dominated. Field evidence suggests the ammonium may originate from nearby landfills, but that local sediments likely contribute the SRP. Ammonium and SRP mass discharges with groundwater were then estimated as the product of the respective concentration distributions and the groundwater flux distribution. These were determined as approximately 9 and 200 g d-1 for SRP and ammonium, respectively, which compares to stream mass discharges over the observed range of base flows of 20-1100 and 270-7600 g d-1, respectively. This suggests that groundwater from this small reach, and any similar areas along Dyment's Creek, has the potential to contribute substantially to the stream nutrient concentrations.

Changes in the chemistry of acidified Adirondack streams from the early 1980s to 2008

USGS Publications Warehouse

Lawrence, G.B.; Simonin, H.A.; Baldigo, Barry P.; Roy, K.M.; Capone, S.B.

2011-01-01

Lakes in the Adirondack region of New York have partially recovered in response to declining deposition, but information on stream recovery is limited. Here we report results of Adirondack stream monitoring from the early 1980s to 2008. Despite a 50% reduction in atmospheric deposition of sulfur, overall increases in pH of only 0.28 and ANC of 13 μeq L-1 were observed in 12 streams over 23 years, although greater changes did occur in streams with lower initial ANC, as expected. In the North Tributary of Buck Creek with high dissolved organic carbon (DOC) concentrations, SO(4)(2-) concentrations decreased from 1999 to 2008 at a rate of 2.0 μmol L-1 y-1, whereas in the neighboring South Tributary with low DOC concentrations, the decrease was only 0.73 μmol L-1 y-1. Ca2+ leaching decreased in the North Tributary due to the SO(4)(2-) decrease, but this was partially offset by an increase in Ca2+ leaching from increased DOC concentrations.

An overview comparing results from two decades of monitoring for pesticides in the Nation’s streams and rivers, 1992-2001 and 2002-2011

USGS Publications Warehouse

Stone, Wesley W.; Gilliom, Robert J.; Martin, Jeffrey D.

2014-01-01

This report provides an overview of the U.S. Geological Survey National Water-Quality Assessment program and National Stream Quality Accounting Network findings for pesticide occurrence in U.S. streams and rivers during 2002–11 and compares them to findings for the previous decade (1992–2001). In addition, pesticide stream concentrations were compared to Human Health Benchmarks (HHBs) and chronic Aquatic Life Benchmarks (ALBs). The comparisons between the decades were intended to be simple and descriptive. Trends over time are being evaluated separately in a series of studies involving rigorous trend analysis. During both decades, one or more pesticides or pesticide degradates were detected more than 90 percent of the time in streams across all types of land uses. For individual pesticides during 2002–11, atrazine (and degradate, deethylatrazine), carbaryl, fipronil (and degradates), metolachlor, prometon, and simazine were detected in streams more than 50 percent of the time. In contrast, alachlor, chlorpyrifos, cyanazine, diazinon, EPTC, Dacthal, and tebuthiuron were detected less frequently in streams during the second decade than during the first decade. During 2002–11, only one stream had an annual mean pesticide concentration that exceeded an HHB. In contrast, 17 percent of agriculture land-use streams and one mixed land-use stream had annual mean pesticide concentrations that exceeded HHBs during 1992–2001. The difference between the first and second decades in terms of percent of streams exceeding HHBs was attributed to regulatory changes. During 2002–11, nearly two-thirds of agriculture land-use streams and nearly one-half of mixed land-use streams exceeded chronic ALBs. For urban land use, 90 percent of the streams exceeded a chronic ALB. Fipronil, metolachlor, malathion, cis-permethrin, and dichlorvos exceeded chronic ALBs for more than 10 percent of the streams. For agriculture and mixed land-use streams, the overall percent of streams that exceeded a chronic ALB was very similar between the decades. For urban land-use streams, the percent of streams exceeding a chronic ALB during 2002–11 nearly doubled that seen during 1992–2001. The reason for this difference was the inclusion of fipronil monitoring during the second decade. Across all land-use streams, the percent of streams exceeding a chronic ALB for fipronil during 2002–11 was greater than all other insecticides during both decades. The percent of streams exceeding a chronic ALB for metolachlor, chlorpyrifos, diazinon, malathion, and carbaryl decreased from the first decade to the second decade. The results of the 2002–11 summary and comparison to 1992–2001 are consistent with the results from more rigorous trend analysis of pesticide stream concentrations for individual streams in various regions of the U.S.

Environmental Impacts Of Zirab Coal Washing Plant, Mazandaran, Iran

NASA Astrophysics Data System (ADS)

Moore, F.; Esmaeili, A.

2009-04-01

Extraction and beneficiation operations associated with coal mining increase the rate of chemical reaction of waste material to air and water media. Zirab coal washing plant is located on the bank of the Cherat stream in Mazandaran province, Iran. coal Mined from central Alborz coalfield mines is not suitable for use in Iranian Steel Corporation. Hence, coal ash content is reduced by physical and chemical processes in this plant. These processes leave a large quantity of liquid and solid wastes that accumulate in waste dump and tailing dam. sediment and water samples taken from Sheshrudbar and Cherat streams and also from Talar river show high concentration of Cd, Mo and As in water samples of coal washing plant and the associated drainage. Eh-pH diagrams revealed the chemical species of elements in water. The enrichment factor and geoaccumulation index show that Cd, Hg, Mo and V are enriched in bottom sediments of the coal washing plant and decrease with increasing distance from the plant. Sequential extraction analysis Results of three sediment samples of Cherat stream show that silicate bound is the major phase in samples taken before and after the plant, but adjacent to the plant, organic bound is dominant. The high concentration of Cd and Mo in the water soluble phase, is noticeable and may result in high mobility and bioavailability of these elements. Mann-Whitney and Wilcoxon tests on six samples, before and after the coal washing plant support the obtained results. Keywords: Zirab; coal washing plant; Sequential extraction analysis; Mann-whitney; Wilcoxon; Enrichment factor; Geoaccumulation index.

Temporal variability in domestic point source discharges and their associated impact on receiving waters.

PubMed

Richards, Samia; Withers, Paul J A; Paterson, Eric; McRoberts, Colin W; Stutter, Marc

2016-11-15

Discharges from the widely distributed small point sources of pollutants such as septic tanks contribute to microbial and nutrient loading of streams and can pose risks to human health and stream ecology, especially during periods of ecological sensitivity. Here we present the first comprehensive data on the compositional variability of septic tank effluents (STE) as a potential source of water pollution during different seasons and the associated links to their influence on stream waters. To determine STE parameters and nutrient variations, the biological and physicochemical properties of effluents sampled quarterly from 12 septic tank systems were investigated with concurrent analyses of upstream and downstream receiving waters. The study revealed that during the warmer dryer months of spring and summer, effluents were similar in composition, as were the colder wetter months of autumn and winter. However, spring/summer effluents differed significantly (P<0.05) from autumn/winter for concentrations of biological oxygen demand (BOD), arsenic, barium (Ba), cobalt, chromium, manganese, strontium (Sr), titanium, tungsten (W) and zinc (Zn). With the exception of BOD, Ba and Sr which were greater in summer and spring, the concentrations of these parameters were greater in winter. Receiving stream waters also showed significant seasonal variation (P≤0.05) in alkalinity, BOD, dissolved organic carbon, sulphate, sulphur, lithium, W, Zn and Escherichiacoli abundance. There was a clear significant influence of STE on downstream waters relative to upstream from the source (P<0.05) for total suspended solids, total particulate P and N, ammonium-N, coliforms and E. coli. The findings of this study found seasonal variation in STE and place effluent discharges as a factor affecting adjacent stream quality and call for appropriate measures to reduce or redirect STE discharges away from water courses. Copyright © 2016 Elsevier B.V. All rights reserved.

Transport and fate of nitrate at the ground-water/surface-water interface

USGS Publications Warehouse

Puckett, L.J.; Zamora, C.; Essaid, H.; Wilson, J.T.; Johnson, H.M.; Brayton, M.J.; Vogel, J.R.

2008-01-01

Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic, mineralogical, chemical, dissolved gas, and isotopic data, were used to determine the processes controlling transport and fate of NO3- in streambeds at five sites across the USA. Water samples were collected from streambeds at depths ranging from 0.3 to 3 m at three to five points across the stream and in two to five separate transects. Residence times of water ranging from 0.28 to 34.7 d m-1 in the streambeds of N-rich watersheds played an important role in allowing denitrification to decrease NO3- concentrations. Where potential electron donors were limited and residence times were short, denitrification was limited. Consequently, in spite of reducing conditions at some sites, NO3- was transported into the stream. At two of the five study sites, NO3- in surface water infiltrated the streambeds and concentrations decreased, supporting current models that NO3- would be retained in N-rich streams. At the other three study sites, hydrogeologic controls limited or prevented infiltration of surface water into the streambed, and ground-water discharge contributed to NO 3- loads. Our results also show that in these low hydrologic-gradient systems, storm and other high-flow events can be important factors for increasing surface-water movement into streambeds. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Source water controls on the character and origin of dissolved organic matter in streams of the Yukon River basin, Alaska

USGS Publications Warehouse

O'Donnell, Jonathan A.; Aiken, George R.; Kane, Evan S.; Jones, Jeremy B.

2010-01-01

Climate warming and permafrost degradation at high latitudes will likely impact watershed hydrology, and consequently, alter the concentration and character of dissolved organic carbon (DOC) in northern rivers. We examined seasonal variation of DOC chemistry in 16 streams of the Yukon River basin, Alaska. Our primary objective was to evaluate the relationship between source water (shallow versus deep groundwater flow paths) and DOC chemical composition. Using base cation chemistry and principal component analysis, we observed high contributions of deep groundwater to glacial and clearwater streams, whereas blackwater streams received larger contributions from shallow groundwater sources. DOC concentration and specific ultraviolet absorbance peaked during spring snowmelt in all streams, and were consistently higher in blackwater streams than in glacial and clearwater streams. The hydrophobic acid fraction of DOC dominated across all streams and seasons, comprising between 35% and 56% of total DOC. The hydrophilic acid fraction of DOC was more prominent in glacial (23% ± 3%) and clearwater streams (19% ± 1%) than in blackwater streams (16% ± 1%), and was enriched during winter base flow (29% ± 1%) relative to snowmelt and summer base flow. We observed that an increase in the contribution of deep groundwater to streamflow resulted in decreased DOC concentration, aromaticity, and DOC-to-dissolved organic nitrogen ratio, and an increase in the proportion of hydrophilic acids relative to hydrophobic acids. Our findings suggest that future permafrost degradation and higher contributions of groundwater to streamflow may result in a higher fraction of labile DOM in streams of the Yukon basin.

Long-Term Data Reveal Patterns and Controls on Stream Water Chemistry in a Forested Stream: Walker Branch, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lutz, Brian D; Mulholland, Patrick J; Bernhardt, Emily

2012-01-01

We present 20 years of weekly stream water chemistry, hydrology, and climate data for the Walker Branch watershed in eastern Tennessee, USA. Since 1989, the watershed has experienced a similar to 1.08 degrees C increase in mean annual temperature, a similar to 20% decline in precipitation, and a similar to 30% increase in forest evapotranspiration rates. As a result, stream runoff has declined by similar to 34%. We evaluate long-term trends in stream water concentrations and fluxes for nine solutes and use wet deposition data to calculate approximate watershed input-output budgets. Dissolved constituents were classified as geochemical solutes (Ca2+, Mg2+,more » and SO42-) or nutrients (NH4+, NO3-, soluble reactive phosphorus [SRP], total soluble nitrogen [TSN], total soluble phosphorus [TSP], and dissolved organic carbon [DOC]). Geochemical solutes are predominantly controlled by discharge, and the long-term changes in catchment hydrology have led to significant trends in the concentrations and fluxes of these solutes. Further, the trends in geochemical solute concentrations indicate shifting soil flowpath contributions to streamflow generation through time, with deep groundwater having a greater proportional contribution in recent years. Despite dramatic changes in watershed runoff, there were no trends in inorganic nutrient concentrations (NH4+, NO3-, and SRP). While most nutrients entering the watershed are retained, stream fluxes of nutrient solutes have declined significantly as a result of decreasing runoff. Nutrient concentrations in the stream exhibit large seasonality controlled by in-stream biological uptake. Stream benthic communities are sensitive to hydrologic disturbance, and changes in the frequency or intensity of storm events through time can affect nutrient fluxes. Stream NO3- concentrations are also sensitive to drought, with concentrations decreasing (increasing) if conditions during the three years prior to the time of sampling were drier (wetter) than the long-term mean. Future changes in the incidence of storm events, as well as the number and duration of droughts, have the potential to significantly alter watershed nutrient losses. Our analysis indicates that changing climates can differentially affect watershed element cycles either through changes in biogeochemical process rates or through changes in catchment hydrology. Furthermore, climate change can include both long-term trending in mean climate variables, as well as changes in the frequency and intensity of storms and droughts, with each of these types of change having distinct effects on the biological and geochemical processes governing different solutes.« less

Water resources of Carbon County, Wyoming

USGS Publications Warehouse

Bartos, Timothy T.; Hallberg, Laura L.; Mason, Jon P.; Norris, Jodi R.; Miller, Kirk A.

2006-01-01

Carbon County is located in the south-central part of Wyoming and is the third largest county in the State. A study to describe the physical and chemical characteristics of surface-water and ground-water resources in Carbon County was conducted by the U.S. Geological Survey in cooperation with the Wyoming State Engineer's Office. Evaluations of streamflow and stream-water quality were limited to analyses of historical data and descriptions of previous investigations. Surface-water data were not collected as part of the study. Forty-five ground-water-quality samples were collected as part of the study and the results from an additional 618 historical ground-water-quality samples were reviewed. Available hydrogeologic characteristics for various aquifers in hydrogeologic units throughout the county also are described. Flow characteristics of streams in Carbon County vary substantially depending on regional and local basin char-acteristics and anthropogenic factors. Precipitation in the county is variable with high mountainous areas receiving several times the annual precipitation of basin lowland areas. For this reason, streams with headwaters in mountainous areas generally are perennial, whereas most streams in the county with headwaters in basin lowland areas are ephemeral, flowing only as a result of regional or local rainfall or snowmelt runoff. Flow characteristics of most perennial streams are altered substantially by diversions and regulation. Water-quality characteristics of selected streams in and near Carbon County during water years 1966 through 1986 varied. Concentrations of dissolved constituents and suspended sediment were smallest at sites on streams with headwaters in mountainous areas because of resistant geologic units, large diluting streamflows, and increased vegetative cover compared to sites on streams with headwaters in basin lowlands. Both water-table and artesian conditions occur in aquifers within the county. Shallow ground water is available throughout the county, although much of it is only marginally suitable or is unsuitable for domestic and irrigation uses mainly because of high total dissolved solids (TDS) concentrations. Suitable ground water for livestock use is available in most areas of the county. Ground-water quality tends to deteriorate with increasing distance from recharge areas and with increasing depth below land surface. Ground water from depths greater than a few thousand feet tends to have TDS concentrations that make it moderately saline to briny. In some areas, even shallow ground water is moderately saline. Specific constituents in parts of some aquifers in the county occur in relatively high concentrations when compared to U.S. Environmental Protection Agency drinking-water standards; for example, relatively high concentrations of sulfate, chloride, fluoride, boron, iron, manganese, and radon were found in several aquifers. The estimated mean daily water use in Carbon County in 2000 was about 320 million gallons per day. Water used for irrigation accounted for about 98 percent of this total. About 98 percent of the total water used was supplied by surface water and about 2 percent by ground water. Excluding irrigation, ground water comprised about 78 percent of total water use in Carbon County. Although ground water is used to a much lesser extent than surface water, in many areas of the county it is the only available water source.

Characteristics and trends of streamflow and dissolved solids in the upper Colorado River Basin, Arizona, Colorado, New Mexico, Utah, and Wyoming

USGS Publications Warehouse

Liebermann, Timothy D.; Mueller, David K.; Kircher, James E.; Choquette, Anne F.

1989-01-01

Annual and monthly concentrations and loads of dissolved solids and major constituents were estimated for 70 streamflow-gaging stations in the Upper Colorado River Basin. Trends in streamflow, dissolved-solids concentrations, and dissolved-solids loads were identified. Nonparametric trend-analysis techniques were used to determine step trends resulting from human activities upstream and long-term monotonic trends. Results were compared with physical characteristics of the basin and historical water-resource development in the basin to determine source areas of dissolved solids and possible cause of trends. Mean annual dissolved-solids concentration increases from less than 100 milligrams per liter in the headwater streams to more than 500 milligrams per liter in the outflow from the Upper Colorado River Basin. All the major tributaries that have high concentrations of dissolved solids are downstream from extensive areas of irrigated agriculture. However, irrigation predated the period of record for most sites and was not a factor in many identified trends. Significant annual trends were identified for 30 sites. Most of these trends were related to transbasin exports, changes in land use, salinity-control practices, or reservoir development. The primary factor affecting streamflow and dissolved-solids concentration and load has been the construction of large reservoirs. Reservoirs have decreased the seasonal and annual variability of streamflow and dissolved solids in streams that drain the Gunnison and San Juan River basins. Fontenelle and Flaming Gorge Reservoirs have increased the dissolved-solids load in the Green River because of dissolution of mineral salts from the bank material. The largest trends occurred downstream from Lake Powell. However, the period of record since the completion of filling was too short to estimate the long-term effects of that reservoir.

Uranium hydrogeochemical and stream sediment reconnaissance of the Albuquerque NTMS Quadrangle, New Mexico, including concentrations of forty-three additional elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maassen, L.W.; Bolivar, S.L.

1979-06-01

The Los Alamos Scientific Laboratory conducted a hydrogeochemical and stream sediment reconnaissance for uranium. Totals of 408 water and 1538 sediment samples were collected from 1802 locations over a 20 100-km/sup 2/ area at an average density of one location per 11 km/sup 2/. Water samples were collected from springs, wells, and streams; sediments samples were collected predominantly from streams, but also from springs. All water samples were analyzed for uranium and 12 other elements. Sediment samples were analyzed for uranium and 42 additional elements. The uranium concentrations in water samples range from below the detection limit of 0.02 ppBmore » to 194.06 ppB. The mean uranium concentration for all water types containing < 40 ppB uranium is 1.98 ppB. Six samples contained uranium concentrations > 40.00 ppB. Well waters have the highest mean uranium concentration; spring waters have the lowest. Clusters of water samples that contain anomalous uranium concentrations are delineated in nine areas. Sediments collected from the quadrangle have uranium concentrations that range between 0.63 ppM and 28.52 ppM, with a mean for all sediments of 3.53 ppM. Eight areas containing clusters of sediments with anomalous uranium concentrations are delineated. One cluster contains sample locations within the Ambrosia Lake uranium district. Five clusters of sediment samples with anomalous uranium concentrations were collected from streams that drain the Jemez volcanic field. Another cluster defines an area just northeast of Albuquerque where streams drain Precambrian rocks, predominantly granites, of the Sandia Mountains. The last cluster, consisting of spring sediments from Mesa Portales, was collected near the contact of the Tertiary Ojo Alamo sandstone with underlying Cretaceous sediments. Sediments from these springs exhibit some of the highest uranium values reported and are associated with high uranium/thorium ratios.« less

Water quality effects of herded stream crossings by domestic sheep bands.

PubMed

Clark, Patrick E; Moffet, Corey A; Lewis, Gregory S; Seyfried, Mark S; Hardegree, Stuart P; Pierson, Fredrick B

2012-01-01

Livestock impacts on total suspended solids (TSS) and pathogen (e.g., ) levels in rangeland streams are a serious concern worldwide. Herded stream crossings by domestic sheep () are periodic, necessary managerial events on high-elevation rangelands, but their impacts on stream water quality are largely unknown. We evaluated the effects of herded, one-way crossings by sheep bands (about 2000 individuals) on TSS and concentration and load responses in downstream waters. Crossing trials were conducted during the summers of 2005 and 2006 on two reaches within each of three perennial streams in the Centennial Mountains of eastern Idaho and southwestern Montana. Water samples were collected at 2-min intervals at an upstream background station and at stations 25, 100, 500, and 1500 m downstream just before and during each crossing trial. Crossings produced substantial increases in TSS and concentrations and loads downstream, but these concentration increases were localized and short lived. Maximum TSS concentration was highest 25 m downstream, declined as a function of downstream distance, and at 500 m downstream was similar to background. Post-peak TSS concentrations at all downstream stations decreased to <25 mg L within 24 to 48 min after reaching their maxima. Findings for concentration and load responses were similar to that of TSS but less clear cut. Stream-crossing sheep do affect water quality; therefore, producers and resource managers should continue to evaluate the efficacy of herdsmanship techniques for reducing water quality impact. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

USGS Publications Warehouse

Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

1988-01-01

The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

Spatial distribution of mercury in southeastern Alaskan streams influenced by glaciers, wetlands, and salmon

USGS Publications Warehouse

Nagorski, Sonia A.; Engstrom, Daniel R.; Hudson, John P.; Krabbenhoft, David P.; Hood, Eran; DeWild, John F.; Aiken, George R.

2014-01-01

Southeastern Alaska is a remote coastal-maritime ecosystem that is experiencing increased deposition of mercury (Hg) as well as rapid glacier loss. Here we present the results of the first reported survey of total and methyl Hg (MeHg) concentrations in regional streams and biota. Overall, streams draining large wetland areas had higher Hg concentrations in water, mayflies, and juvenile salmon than those from glacially-influenced or recently deglaciated watersheds. Filtered MeHg was positively correlated with wetland abundance. Aqueous Hg occurred predominantly in the particulate fraction of glacier streams but in the filtered fraction of wetland-rich streams. Colonization by anadromous salmon in both glacier and wetland-rich streams may be contributing additional marine-derived Hg. The spatial distribution of Hg in the range of streams presented here shows that watersheds are variably, yet fairly predictably, sensitive to atmospheric and marine inputs of Hg.

Rare Earth Elements in Alberta Oil Sand Process Streams

DOE PAGES

Roth, Elliot; Bank, Tracy; Howard, Bret; ...

2017-04-05

The concentrations of rare earth elements in Alberta, Canada oil sands and six oil sand waste streams were determined using inductively coupled plasma mass spectrometry (ICP–MS). The results indicate that the rare earth elements (REEs) are largely concentrated in the tailings solvent recovery unit (TSRU) sample compared to the oil sand itself. The concentration of lanthanide elements is ~1100 mg/kg (1100 ppm or 0.11 weight %), which represents a >20× increase in the concentration compared to the oil sand itself and a >7× increase compared to the North American Shale Composite (NASC). The process water, which is used to extractmore » the oil from oil sands, and the water fraction associated with the different waste streams had very low concentrations of REEs that were near or below the detection limits of the instrument, with the highest total concentration of REEs in the water fraction being less than 10 μg/L (ppb). Size and density separations were completed, and the REEs and other potentially interesting and valuable metals, such as Ti and Zr, were concentrated in different fractions. These results give insights into the possibility of recovering REEs from waste streams generated from oil sand processing.« less

Sediment concentration and turbidity changes during culvert removals.

PubMed

Foltz, Randy B; Yanosek, Kristina A; Brown, Timothy M

2008-05-01

The concentrations of sediment and turbidity in stream water were monitored during culvert removals to determine the short term effects of road obliteration. Sediment concentration was measured at 11 stream crossings among two locations in Idaho and one in Washington. Sediment concentration immediately below the culvert outlet exceeded levels above the culvert outlet by at least three orders of magnitude at all stream crossings. Sediment yields ranged from 170 to less than 1kg in the 24-h period following culvert removal. Turbidity exceeded the regulatory limits during culvert removal at all locations monitored in this study and remained above the limits beyond the monitoring periods of 24h at four of the locations. Sediment concentrations 100m downstream of the culvert outlet were reduced by an order of magnitude, but did not change the turbidity values sufficiently to meet regulatory limits. Sediment concentrations an average of 810m downstream of the culvert outlet were similar to sediment concentrations above the culvert for the entire excavation period and turbidity regulations were met. Mitigation consisting of two straw bales placed in the stream caused a significant reduction in sediment yield from an average of 67kg to an average of 1.6kg.

Rare Earth Elements in Alberta Oil Sand Process Streams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roth, Elliot; Bank, Tracy; Howard, Bret

The concentrations of rare earth elements in Alberta, Canada oil sands and six oil sand waste streams were determined using inductively coupled plasma mass spectrometry (ICP–MS). The results indicate that the rare earth elements (REEs) are largely concentrated in the tailings solvent recovery unit (TSRU) sample compared to the oil sand itself. The concentration of lanthanide elements is ~1100 mg/kg (1100 ppm or 0.11 weight %), which represents a >20× increase in the concentration compared to the oil sand itself and a >7× increase compared to the North American Shale Composite (NASC). The process water, which is used to extractmore » the oil from oil sands, and the water fraction associated with the different waste streams had very low concentrations of REEs that were near or below the detection limits of the instrument, with the highest total concentration of REEs in the water fraction being less than 10 μg/L (ppb). Size and density separations were completed, and the REEs and other potentially interesting and valuable metals, such as Ti and Zr, were concentrated in different fractions. These results give insights into the possibility of recovering REEs from waste streams generated from oil sand processing.« less

Spatial heterogeneity of within-stream methane concentrations

USGS Publications Warehouse

Crawford, John T.; Loken, Luke C.; West, William E.; Crary, Benjamin; Spawn, Seth A.; Gubbins, Nicholas; Jones, Stuart E.; Striegl, Robert G.; Stanley, Emily H.

2017-01-01

Streams, rivers, and other freshwater features may be significant sources of CH4 to the atmosphere. However, high spatial and temporal variabilities hinder our ability to understand the underlying processes of CH4 production and delivery to streams and also challenge the use of scaling approaches across large areas. We studied a stream having high geomorphic variability to assess the underlying scale of CH4 spatial variability and to examine whether the physical structure of a stream can explain the variation in surface CH4. A combination of high-resolution CH4 mapping, a survey of groundwater CH4 concentrations, quantitative analysis of methanogen DNA, and sediment CH4 production potentials illustrates the spatial and geomorphic controls on CH4 emissions to the atmosphere. We observed significant spatial clustering with high CH4 concentrations in organic-rich stream reaches and lake transitions. These sites were also enriched in the methane-producing mcrA gene and had highest CH4 production rates in the laboratory. In contrast, mineral-rich reaches had significantly lower concentrations and had lesser abundances of mcrA. Strong relationships between CH4and the physical structure of this aquatic system, along with high spatial variability, suggest that future investigations will benefit from viewing streams as landscapes, as opposed to ecosystems simply embedded in larger terrestrial mosaics. In light of such high spatial variability, we recommend that future workers evaluate stream networks first by using similar spatial tools in order to build effective sampling programs.

Electrodialysis-based separation process for salt recovery and recycling from waste water

DOEpatents

Tsai, S.P.

1997-07-08

A method for recovering salt from a process stream containing organic contaminants is provided, comprising directing the waste stream to a desalting electrodialysis unit so as to create a concentrated and purified salt permeate and an organic contaminants-containing stream, and contacting said concentrated salt permeate to a water-splitting electrodialysis unit so as to convert the salt to its corresponding base and acid. 6 figs.

Electrodialysis-based separation process for salt recovery and recycling from waste water

DOEpatents

Tsai, Shih-Perng

1997-01-01

A method for recovering salt from a process stream containing organic contaminants is provided, comprising directing the waste stream to a desalting electrodialysis unit so as to create a concentrated and purified salt permeate and an organic contaminants containing stream, and contacting said concentrated salt permeate to a water-splitting electrodialysis unit so as to convert the salt to its corresponding base and acid.

Diminished Stream Nitrate Concentrations Linked to Dissolved Organic Carbon Dynamics After Leaf Fall

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Doctor, D. H.; Kendall, C.

2004-05-01

Thermodynamic coupling of the nitrogen and carbon cycles has broad implications for controls on catchment nutrient fluxes. In the northeast US, leaf fall occurs in early October and the availability of organic carbon increases as the leaves decompose. At the Sleepers River Research Watershed in northeastern Vermont (USA), we sampled stream chemistry from seven nested catchments to determine how stream dissolved organic carbon (DOC) and nitrate vary as a function of flow conditions, land-use, and basin size in response to leaf fall. Following leaf fall, nitrate concentration patterns were quantitatively different from other times of the year. Under baseflow conditions, stream and soil water DOC concentrations were higher than normal, whereas nitrate concentrations declined sharply at the five smallest catchments and more modestly at the two largest catchments. Under high flow conditions, flushing of nitrate was observed, as is typical for stormflow response at Sleepers River. Our field data suggest that in-stream processing of nitrate is likely thermodynamically and kinetically favorable under baseflow but not at higher flow conditions when expanding variable source areas make hydrological connections between nitrate source areas and streams. We are working to evaluate this hypothesis with isotopic and other monitoring data, and to model the coupled interactions of water, DOC, and nitrate fluxes in these nested catchments.

Coupling of hydrologic transport and chemical reactions in a stream affected by acid mine drainage

USGS Publications Warehouse

Kimball, B.A.; Broshears, R.E.; Bencala, K.E.; McKnight, Diane M.

1994-01-01

Experiments in St. Kevin Gulch, an acid mine drainage stream, examined the coupling of hydrologic transport to chemical reactions affecting metal concentrations. Injection of LiCl as a conservative tracer was used to determine discharge and residence time along a 1497-m reach. Transport of metals downstream from inflows of acidic, metal-rich water was evaluated based on synoptic samples of metal concentrations and the hydrologic characteristics of the stream. Transport of SO4 and Mn was generally conservative, but in the subreaches most affected by acidic inflows, transport was reactive. Both 0.1-??m filtered and particulate Fe were reactive over most of the stream reach. Filtered Al partitioned to the particulate phase in response to high instream concentrations. Simulations that accounted for the removal of SO4, Mn, Fe, and Al with first-order reactions reproduced the steady-state profiles. The calculated rate constants for net removal used in the simulations embody several processes that occur on a stream-reach scale. The comparison between rates of hydrologie transport and chemical reactions indicates that reactions are only important over short distances in the stream near the acidic inflows, where reactions occur on a comparable time scale with hydrologic transport and thus affect metal concentrations.

Septic tank discharges as multi-pollutant hotspots in catchments.

PubMed

Richards, Samia; Paterson, Eric; Withers, Paul J A; Stutter, Marc

2016-01-15

Small point sources of pollutants such as septic tanks are recognised as significant contributors to streams' pathogen and nutrient loadings, however there is little data in the UK on which to judge the potential risks that septic tank effluents (STEs) pose to water quality and human health. We present the first comprehensive analysis of STE to help assess multi-pollutant characteristics, management-related risk factors and potential tracers that might be used to identify STE sources. Thirty-two septic tank effluents from residential households located in North East of Scotland were sampled along with adjacent stream waters. Biological, physical, chemical and fluorescence characterisation was coupled with information on system age, design, type of tank, tank management and number of users. Biological characterisation revealed that total coliforms and Escherichia coli (E. coli) concentration ranges were: 10(3)-10(8) and 10(3)-10(7)MPN/100 mL, respectively. Physical parameters such as electrical conductivity, turbidity and alkalinity ranged 160-1730 μS/cm, 8-916 NTU and 15-698 mg/L, respectively. Effluent total phosphorus (TP), soluble reactive P (SRP), total nitrogen (TN) and ammonium-N (NH4-N) concentrations ranged 1-32, <1-26, 11-146 and 2-144 mg/L, respectively. Positive correlations were obtained between phosphorus, sodium, potassium, barium, copper and aluminium. Domestic STE may pose pollution risks particularly for NH4-N, dissolved P, SRP, copper, dissolved N, and potassium since enrichment factors were >1651, 213, 176, 63, 14 and 8 times that of stream waters, respectively. Fluorescence characterisation revealed the presence of tryptophan peak in the effluent and downstream waters but not detected upstream from the source. Tank condition, management and number of users had influenced effluent quality that can pose a direct risk to stream waters as multiple points of pollutants. Copyright © 2015 Elsevier B.V. All rights reserved.

Factors controlling soil water and stream water aluminum concentrations after a clearcut in a forested watershed with calcium-poor soils

USGS Publications Warehouse

McHale, M.R.; Burns, Douglas A.; Lawrence, G.B.; Murdoch, Peter S.

2007-01-01

The 24 ha Dry Creek watershed in the Catskill Mountains of southeastern New York State USA was clearcut during the winter of 1996-1997. The interactions among acidity, nitrate (NO3- ), aluminum (Al), and calcium (Ca2+) in streamwater, soil water, and groundwater were evaluated to determine how they affected the speciation, solubility, and concentrations of Al after the harvest. Watershed soils were characterized by low base saturation, high exchangeable Al concentrations, and low exchangeable base cation concentrations prior to the harvest. Mean streamwater NO3- concentration was about 20 ??mol l-1 for the 3 years before the harvest, increased sharply after the harvest, and peaked at 1,309 ??mol l -1 about 5 months after the harvest. Nitrate and inorganic monomeric aluminum (Alim) export increased by 4-fold during the first year after the harvest. Alim mobilization is of concern because it is toxic to some fish species and can inhibit the uptake of Ca2+ by tree roots. Organic complexation appeared to control Al solubility in the O horizon while ion exchange and possibly equilibrium with imogolite appeared to control Al solubility in the B horizon. Alim and NO3- concentrations were strongly correlated in B-horizon soil water after the clearcut (r2 = 0.96), especially at NO3- concentrations greater than 100 ??mol l-1. Groundwater entering the stream from perennial springs contained high concentrations of base cations and low concentrations of NO3- which mixed with acidic, high Alim soil water and decreased the concentration of Alim in streamwater after the harvest. Five years after the harvest soil water NO 3- concentrations had dropped below preharvest levels as the demand for nitrogen by regenerating vegetation increased, but groundwater NO3- concentrations remained elevated because groundwater has a longer residence time. As a result streamwater NO3- concentrations had not fallen below preharvest levels, even during the growing season, 5 years after the harvest because of the contribution of groundwater to the stream. Streamwater NO3- and Alim concentrations increased more than reported in previous forest harvesting studies and the recovery was slower likely because the watershed has experienced several decades of acid deposition that has depleted initially base-poor soils of exchangeable base cations and caused long-term acidification of the soil. ?? 2007 Springer Science+Business Media B.V.

Complex mixtures of Pesticides in Midwest U.S. streams indicated by POCIS time-integrating samplers

USGS Publications Warehouse

Van Metre, Peter C.; Alvarez, David; Mahler, Barbara J.; Nowell, Lisa H.; Sandstrom, Mark W.; Moran, Patrick W.

2017-01-01

The Midwest United States is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability in pesticide concentrations makes characterization of their exposure to organisms challenging. To compensate for the effects of temporal variability, we deployed polar organic chemical integrative samplers (POCIS) in 100 small streams across the Midwest for about 5 weeks during summer 2013 and analyzed the extracts for 227 pesticide compounds. Analysis of water samples collected weekly for pesticides during POCIS deployment allowed for comparison of POCIS results with periodic water-sampling results. The median number of pesticides detected in POCIS extracts was 62, and 141 compounds were detected at least once, indicating a high level of pesticide contamination of streams in the region. Sixty-five of the 141 compounds detected were pesticide degradates. Mean water concentrations estimated using published POCIS sampling rates strongly correlated with means of weekly water samples collected concurrently, however, the POCIS-estimated concentrations generally were lower than the measured water concentrations. Summed herbicide concentrations (units of ng/POCIS) were greater at agricultural sites than at urban sites but summed concentrations of insecticides and fungicides were greater at urban sites. Consistent with these differences, summed concentrations of herbicides correlate to percent cultivated crops in the watersheds and summed concentrations of insecticides and fungicides correlate to percent urban land use. With the exception of malathion concentrations at nine sites, POCIS-estimated water concentrations of pesticides were lower than aquatic-life benchmarks. The POCIS provide an alternative approach to traditional water sampling for characterizing chronic exposure to pesticides in streams across the Midwest region.

Complex mixtures of Pesticides in Midwest U.S. streams indicated by POCIS time-integrating samplers.

PubMed

Van Metre, Peter C; Alvarez, David A; Mahler, Barbara J; Nowell, Lisa; Sandstrom, Mark; Moran, Patrick

2017-01-01

The Midwest United States is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability in pesticide concentrations makes characterization of their exposure to organisms challenging. To compensate for the effects of temporal variability, we deployed polar organic chemical integrative samplers (POCIS) in 100 small streams across the Midwest for about 5 weeks during summer 2013 and analyzed the extracts for 227 pesticide compounds. Analysis of water samples collected weekly for pesticides during POCIS deployment allowed for comparison of POCIS results with periodic water-sampling results. The median number of pesticides detected in POCIS extracts was 62, and 141 compounds were detected at least once, indicating a high level of pesticide contamination of streams in the region. Sixty-five of the 141 compounds detected were pesticide degradates. Mean water concentrations estimated using published POCIS sampling rates strongly correlated with means of weekly water samples collected concurrently, however, the POCIS-estimated concentrations generally were lower than the measured water concentrations. Summed herbicide concentrations (units of ng/POCIS) were greater at agricultural sites than at urban sites but summed concentrations of insecticides and fungicides were greater at urban sites. Consistent with these differences, summed concentrations of herbicides correlate to percent cultivated crops in the watersheds and summed concentrations of insecticides and fungicides correlate to percent urban land use. With the exception of malathion concentrations at nine sites, POCIS-estimated water concentrations of pesticides were lower than aquatic-life benchmarks. The POCIS provide an alternative approach to traditional water sampling for characterizing chronic exposure to pesticides in streams across the Midwest region. Published by Elsevier Ltd.

Stream-Groundwater Interaction Buffers Seasonal Changes in Urban Stream Water Quality

NASA Astrophysics Data System (ADS)

Ledford, S. H.; Lautz, L. K.

2013-12-01

Urban streams in the northeastern United States have large road salt inputs during winter, increased nonpoint sources of inorganic nitrogen, and decreased short-term and permanent storage of nutrients. Meadowbrook Creek, a first order stream in Syracuse, New York, flows along a negative urbanization gradient, from a channelized and armored stream running through the middle of a roadway to a pool-riffle stream meandering through a broad, vegetated floodplain with a riparian aquifer. In this study we investigated how reconnection to groundwater and introduction of riparian vegetation impacted surface water chemistry by making bi-weekly longitudinal surveys of stream water chemistry in the creek from May 2012 until June 2013. Chloride concentrations in the upstream, urban reach of Meadowbrook Creek were strongly influenced by discharge of road salt to the creek during snow melt events in winter and by the chemistry of water draining an upstream retention basin in summer. Chloride concentrations ranged from 161.2 mg/L in August to 2172 mg/L in February. Chloride concentrations in the downstream, 'connected' reach had less temporal variation, ranging from 252.0 mg/L in August to 1049 mg/L in January, and were buffered by groundwater discharge, as the groundwater chloride concentrations during the sampling period ranged from 84.0 to 655.4 mg/L. Groundwater discharge resulted in higher chloride concentrations in summer and lower concentrations in winter in the connected reach relative to the urban reach, minimizing annual variation. In summer, there was little-to-no nitrate in the urban reach due to a combination of limited sources and high primary productivity. In contrast, during the summer, nitrate concentrations reached over 1 mg N/L in the connected reach due to the presence of riparian vegetation and lower nitrate uptake due to cooler temperatures and shading. During the winter, when temperatures fell below freezing, nitrate concentrations in the urban reach increased to around 0.58 mg N/L, but were still lower than the connected reach, which averaged 0.88 mg N/L. Groundwater discharge rates were measured longitudinally along the creek during a constant rate Rhodamine WT injection and also confirmed qualitatively by longitudinal changes in stream sulfate and δ18O. The buffering capability of groundwater discharge in urban systems has implications for managers trying to mitigate the effects of urbanization on surface water.

Concentrations, fluxes, and yields of nitrogen, phosphorus, and suspended sediment in the Illinois River basin, 1996-2000

USGS Publications Warehouse

Terrio, Paul J.

2006-01-01

Concentrations, spatial and temporal variations, and fluxes of nitrogen, phosphorus, and suspended sediment were determined for 16 streams in the Illinois River Basin, Illinois from October 1996 through September 2000. Water samples were collected through the National Water-Quality Assessment's Lower Illinois River Basin (LIRB) and Upper Illinois River Basin (UIRB) Study Units on a monthly to weekly frequency from watersheds representing predominantly agricultural and urban land, as well as areas of mixed land-use. Streams in agricultural watersheds had high concentrations and fluxes of nitrate nitrogen, whereas streams in predominantly urban watersheds had high concentrations (above background levels) of ammonia nitrogen, organic nitrogen, and phosphorus. Median concentrations of nitrate nitrogen and total phosphorus were similar at the two Illinois River sampling stations (Illinois River at Ottawa, Ill. and Illinois River at Valley City, Ill.) that represented the downstream points of the UIRB and LIRB Study Units, respectively, and integrated multiple land-use areas. Concentrations of nitrogen were typically highest in the spring and lowest in the fall in agricultural watersheds, but highest in the winter in urban watersheds. Phosphorus concentrations in urban watersheds were highest in the fall and winter, but there was minimal seasonal variation in phosphorus concentrations in agricultural watersheds. Concentrations of nitrate and total nitrogen were affected primarily by non-point sources and hydrologic factors such as streamflow, storm intensity, watershed configuration, and soil permeability, whereas concentrations of phosphorus were affected largely by point-source contributions that typically have little seasonal variation. Seasonal variation in hydrologic conditions was an important factor for seasonal variation in nutrient concentration. Fluxes and yields of nitrogen and phosphorus forms varied substantially throughout the Illinois River Basin, and yields of specific nutrient forms were determined primarily by upstream land uses. Yields of nitrate nitrogen were highest in predominantly agricultural watersheds, whereas yields of phosphorus and ammonia nitrogen were highest in urban watersheds with wastewater effluent contributions. Yields of both total nitrogen and total phosphorus were similar at the two Illinois River stations representing the integrated UIRB and LIRB Study Units. Concentrations of suspended sediment ranged from 1 to 3,110 milligrams per liter (mg/L), with median concentrations generally higher in the UIRB. Suspended-sediment concentrations were highest and most variable in the LaMoine River Basin. The median concentration of suspended sediment in the Illinois River at Valley City, Ill. (155 mg/L) was twice as high as that at Ottawa, Ill. (80 mg/L). Fluxes of suspended sediment generally corresponded to watershed size and yields from agricultural watersheds were larger than yields from urban watersheds. The flux in the Illinois River at Valley City, Ill. (4,880,000 tons per year) was approximately four times the flux in the Illinois River at Ottawa, Ill. (1,060,000 tons per year).

Effects of urban stream burial on nitrogen uptake and ...

EPA Pesticide Factsheets

Urbanization has resulted in extensive burial and channelization of headwater streams, yet little is known about impacts on stream ecosystem functions critical for reducing downstream nitrogen pollution. To characterize the biogeochemical impact of stream burial, we measured NO3- uptake, using 15N-NO3- isotope tracer releases, and whole stream metabolism, during four seasons in three paired buried and open streams reaches within the Baltimore Ecosystem Study Long-term Ecological Research Network. Stream burial increased NO3- uptake lengths, by a factor of 7.5 (p < 0.01) and decreased nitrate uptake velocity and areal nitrate uptake rate by factors of 8.2 (p = 0.01) and 9.6 (p < 0.001), respectively. Stream burial decreased gross primary productivity by a factor of 9.2 (p < 0.05) and decreased ecosystem respiration by a factor of 4.2 (p = 0.06). From statistical analysis of Excitation Emissions Matrices (EEMs), buried streams were also found to have significantly less labile dissolved organic matter. Furthermore, buried streams had significantly lower transient storage and water temperatures. Overall, differences in NO3- uptake and metabolism were primarily explained by decreased transient storage and light availability in buried streams. We estimate that stream burial increases daily watershed nitrate export by as much as 500% due to decreased in-stream retention and may considerably decrease carbon export via decreased primary production. These results

Evaluation of USEPA method 1622 for detection of Cryptosporidium oocysts in stream waters

USGS Publications Warehouse

Simmons, O. D.; Sobsey, M.D.; Schaefer, F. W.; Francy, D.S.; Nally, R.A.; Heaney, C.D.

2001-01-01

To improve surveillance for Cryptosporidium oocysts in water, the US Environmental Protection Agency developed method 1622, which consists of filtration, concentration, immunomagnetic separation, fluorescent antibody and 4, 6-diamidino-2-phenylindole (DAPI) counter-staining, and microscopic evaluation. Two filters were compared for analysis of 11 stream water samples collected throughout the United States. Replicate 10-L stream water samples (unspiked and spiked with 100-250 oocysts) were tested to evaluate matrix effects. Oocyst recoveries from the stream water samples averaged 22% (standard deviation [SD] = ??17%) with a membrane disk and 12% (SD = ??6%) with a capsule filter. Oocyst recoveries from reagent water precision and recovery samples averaged 39% (SD = ??13%) with a membrane disk and 47% (SD = ??19%) with a capsule filter. These results demonstrate that Cryptosporidium oocysts can be recovered from stream waters using method 1622, but recoveries are lower than those from reagent-grade water. This research also evaluated concentrations of indicator bacteria in the stream water samples. Because few samples were oocyst-positive, relationships between detections of oocysts and concentrations of indicator organisms could not be determined.

Fuzzy rule based estimation of agricultural diffuse pollution concentration in streams.

PubMed

Singh, Raj Mohan

2008-04-01

Outflow from the agricultural fields carries diffuse pollutants like nutrients, pesticides, herbicides etc. and transports the pollutants into the nearby streams. It is a matter of serious concern for water managers and environmental researchers. The application of chemicals in the agricultural fields, and transport of these chemicals into streams are uncertain that cause complexity in reliable stream quality predictions. The chemical characteristics of applied chemical, percentage of area under the chemical application etc. are some of the main inputs that cause pollution concentration as output in streams. Each of these inputs and outputs may contain measurement errors. Fuzzy rule based model based on fuzzy sets suits to address uncertainties in inputs by incorporating overlapping membership functions for each of inputs even for limited data availability situations. In this study, the property of fuzzy sets to address the uncertainty in input-output relationship is utilized to obtain the estimate of concentrations of a herbicide, atrazine, in a stream. The data of White river basin, a part of the Mississippi river system, is used for developing the fuzzy rule based models. The performance of the developed methodology is found encouraging.

Quality of Streams in Johnson County, Kansas, and Relations to Environmental Variables, 2003-07

USGS Publications Warehouse

Rasmussen, Teresa J.; Poulton, Barry C.; Graham, Jennifer L.

2009-01-01

The quality of streams and relations to environmental variables in Johnson County, northeastern Kansas, were evaluated using water, streambed sediment, land use, streamflow, habitat, algal periphyton (benthic algae), and benthic macroinvertebrate data. Water, streambed sediment, and macroinvertebrate samples were collected in March 2007 during base flow at 20 stream sites that represent 11 different watersheds in the county. In addition, algal periphyton samples were collected twice (spring and summer 2007) at one-half of the sites. Environmental data including water and streambed-sediment chemistry data (primarily nutrients, fecal-indicator bacteria, and organic wastewater compounds), land use, streamflow, and habitat data were used in statistical analyses to evaluate relations between biological conditions and variables that may affect them. This report includes an evaluation of water and streambed-sediment chemistry, assessment of habitat conditions, comparison of biological community attributes (such as composition, diversity, and abundance) among sampling sites, placement of sampling sites into impairment categories, evaluation of biological data relative to environmental variables, and evaluation of changes in biological communities and effects of urbanization. This evaluation is useful for understanding factors that affect stream quality, for improving water-quality management programs, and for documenting changing conditions over time. The information will become increasingly important for protecting streams in the future as urbanization continues. Results of this study indicate that the biological quality at nearly all biological sampling sites in Johnson County has some level of impairment. Periphyton taxa generally were indicative of somewhat degraded conditions with small to moderate amounts of organic enrichment. Camp Branch in the Blue River watershed was the only site that met State criteria for full support of aquatic life in 2007. Since 2003, biological quality improved at one rural sampling site, possibly because of changes in wastewater affecting the site, and declined at three urban sites possibly because of the combined effects of ongoing development. Rural streams in the western and southern parts of the county, with land-use conditions similar to those found at the State reference site (Captain Creek), continue to support some organisms normally associated with healthy streams. Several environmental factors contribute to biological indicators of stream quality. The primary factor explaining biological quality at sites in Johnson County was the amount of urbanization upstream in the watershed. Specific conductance of stream water, which is a measure of dissolved solids in water and is determined primarily by the amount of groundwater contributing to streamflow, the amount of urbanization, and discharges from wastewater and industrial sites, was strongly negatively correlated with biological stream quality as indicated by macroinvertebrate metrics. Concentration of polycyclic aromatic hydrocarbons (PAHs) in streambed sediment also was negatively correlated with biological stream quality. Individual habitat variables that most commonly were positively correlated with biological indicators included stream sinuosity, buffer length, and substrate cover diversity. Riffle substrate embeddedness and sediment deposition commonly were negatively correlated with favorable metric scores. Statistical analysis indicated that specific conductance, impervious surface area (a measure of urbanization), and stream sinuosity explained 85 percent of the variance in macroinvertebrate communities. Management practices affecting environmental variables that appear to be most important for Johnson County streams include protection of stream corridors, measures that reduce the effects of impervious surfaces associated with urbanization, reduction of dissolved solids in stream water, reduction of PAHs entering streams and

Fecal-coliform bacteria concentrations in streams of the Chattahoochee River National Recreation Area, Metropolitan Atlanta, Georgia, May-October 1994 and 1995

USGS Publications Warehouse

Gregory, M. Brian; Frick, Elizabeth A.

2000-01-01

Introduction: The Metropolitan Atlanta area has been undergoing a period of rapid growth and development. The population in the 10-county metropolitan area almost doubled from about 1.5 million people in 1970 to 2.9 million people in 1995 (Atlanta Regional Commission, written commun., 2000). Residential, commercial, and other urban land uses more than tripled during the same period (Frick and others, 1998). The Chattahoochee River is the most utilized water resource in Georgia. The rapid growth of Metropolitan Atlanta and its location downstream of the headwaters of the drainage basin make the Chattahoochee River a vital resource for drinking-water supplies, recreational opportunities, and wastewater assimilation. In 1978, the U.S. Congress declared the natural, scenic, recreation, and other values of 48 miles of the Chattahoochee River from Buford Dam to Peachtree Creek to be of special national significance. To preserve this reach of the Chattahoochee River, the U.S. Congress created the Chattahoochee River National Recreational Area (CRNRA), which includes the Chattahoochee River downstream from Buford Dam to the mouth of Peachtree Creek and a series of park areas adjacent to the river in northern Metropolitan Atlanta Even with this protection, waters of the Chattahoochee River and many of its tributaries in Metropolitan Atlanta did not meet water-quality standards set for designated uses during 1994 and 1995 (fig. 1 and table 1). Much of the degradation of water quality has been associated with areas undergoing rapid urban growth and sprawling suburban development. The resulting conversion of mostly forested land to urban land has multiple adverse effects on water quality. Degradation of water quality may be caused by a number of factors including an increase in nutrient concentrations, sediment and sedimentbound contaminant concentrations (e.g., metals and pesticides) (Frick and others, 1998), and fecal-coliform bacteria concentrations (Center for Watershed Protection, 1999). The presence of fecal-coliform bacteria in streams and rivers indicates that contamination by fecal material from human or animal sources has occurred and contact with these waters can result in exposure to pathogenic bacteria often associated with fecal contamination. During 1994 and 1995, elevated concentrations of fecal-coliform bacteria were the most common reason that the Chattahoochee River and tributaries did not meet their designated uses of drinking-water supply, recreation, and fishing. According to the Georgia Department of Natural Resources (1997), during 1994 and 1995, 67 of 77 stream reaches assessed in Metropolitan Atlanta did not meet or only partially met water-quality requirements for designated uses. Excessive concentrations of fecal-coliform bacteria were a contributing factor in 63 of the 67 streams that did not meet or only partially met designated uses. High concentrations of fecal-coliform bacteria have the potential to reduce the recreational value of the river and pose a continued threat, with unknown health risks, to humans that come in contact with the water while fishing, boating, rafting, wading, and swimming.

Intestinal parasite Acanthocephalus lucii (Acanthocephala) from European perch (Perca fluviatilis) as a bioindicator for lead pollution in the stream "Jevanský potok" near Prague, Czech Republic.

PubMed

Jankovská, Ivana; Miholová, Daniela; Petrtýl, Miloslav; Romočuský, Stěpán; Kalous, Lukáš; Vadlejch, Jaroslav; Cadková, Zuzana; Langrová, Iva

2011-03-01

Lead concentrations in the tissues of perch and its parasites were determined as mg/kg dw. Lead was found at higher concentrations in the acanthocephalans (11.56) than in different tissues (liver, gonads and muscle with skin and bone) of perch. With respect to fish tissues, the highest concentrations of lead were present in the liver (1.24), followed by the gonads (0.57) whereas the lowest concentrations were in the muscle with skin and bone (0.21). The bioconcentration factors for lead indicated that parasites accumulate metals to a higher degree than fish tissues--lead concentrations in acanthocephalans were 9.32, 19.27 and 55.05 higher than in liver, gonads and muscles of host, respectively.

Tradeoffs in Greenhouse Gas Fluxes from Aquatic Ecosystems Along a Rural to Urban Gradient are Driven by N Loading

NASA Astrophysics Data System (ADS)

McDowell, W. H.; Potter, J.

2017-12-01

The effects of urbanization on net greenhouse gas (GHG) exchange from streams and rivers to the atmosphere are poorly understood. Previous work on a few small suburban streams in New Hampshire shows that N2O concentration is strongly seasonal, increases with wetland contact, and can be highest in streams with low CH4 production. Here we expand on these observations using 4 years of weekly samples in multiple headwater streams and a single downstream main stem site. Our results show that within a single drainage network, CH4 concentrations are higher downstream than in any of the small tributaries studied, which span a range of land use and wetland coverage. Methane is also very strongly seasonal in concentration in the tributaries (peaking in late summer), but is aseasonal in the main stem. In contrast, N2O concentrations are strongly seasonal at all sites, but peak in early winter and are much higher in more urban tributaries than the main stem. Urbanization results in a flipping of GHG concentrations, with highest N2O and lowest CH4 in the most urban watershed. CO2 shows no strong patterns with respect to landscape position, urbanization, or season. We examined multiple biogeochemical drivers of net CH4 and N2O production, and found that the increased NO3 concentration associated with urbanization is a good predictor of N2O concentrations in many streams.

Leaching, transport, and methylation of mercury in and around abandoned mercury mines in the Humboldt River basin and surrounding areas, Nevada. Chapter C.

USGS Publications Warehouse

Gray, John E.; Stillings, Lisa L.

2003-01-01

Mercury and methylmercury concentrations were measured in mine wastes, stream sediments, and stream waters collected both proximal and distal from abandoned mercury mines to evaluate mercury contamination and mercury methylation in the Humboldt River system. The climate in the study area is arid, and due to the lack of mine-water runoff, water-leaching laboratory experiments were used to evaluate the potential of mine wastes to release mercury. Mine-waste calcine contains mercury concentrations as high as 14,000 ?g/g. Stream-sediment samples collected within 1 km of the mercury mines studied contain mercury concentrations as high as 170 ?g/g, but sediments collected from the Humboldt River and regional baseline sites have much lower mercury contents, less than 0.44 ?g/g. Similarly, methylmercury concentrations in mine-waste calcine are locally as high as 96 ng/g, but methylmercury contents in stream sediments collected down-stream from the mines and from the Humboldt River are lower (<0.05-0.95 ng/g). Stream-water samples collected below two mines studied contain mercury concentrations ranging from 6 to 2,000 ng/L, whereas mercury contents in Humboldt River and Rye Patch Reservoir water were generally lower, ranging from 2.1 to 9.0 ng/L. Methylmercury concentrations in Humboldt River system water were the lowest in this study (<0.02- 0.27 ng/L). Although mercury and methylmercury concentrations were elevated in some mine-waste calcine and mercury concentrations were locally high in mine-waste leachate samples, data show significant dilution of mercury and lower mercury methylation down gradient from the mines, especially in the sediments and water collected from the Humboldt River, which is more than 8 km from any mercury mines. Data show only minor, local transference of mercury and methylmercury from mine-waste calcine to stream sediment, and then onto the water column, and indicate little transference of mercury from the mine sites to the Humboldt River system.

MERCURY CONCENTRATION IN FISH FROM STREAMS/RIVERS THROUGHOUT THE WESTERN UNITED STATES

EPA Science Inventory

We collected 2,707 fish from 626 stream/river sites in 12 western USA states using a probability design to assess the spatial extent of whole fish mercury (Hg) concentrations. In all large (> 120 mm) fish, Hg concentrations (mean µg¿g-1; SD) in both piscivores (0.260; 0.241) and ...

Bioaccumulation and trophic dilution of human pharmaceuticals across trophic positions of an effluent-dependent wadeable stream

PubMed Central

Du, Bowen; Haddad, Samuel P.; Luek, Andreas; Scott, W. Casan; Saari, Gavin N.; Kristofco, Lauren A.; Connors, Kristin A.; Rash, Christopher; Rasmussen, Joseph B.; Chambliss, C. Kevin; Brooks, Bryan W.

2014-01-01

Though pharmaceuticals are increasingly observed in a variety of organisms from coastal and inland aquatic systems, trophic transfer of pharmaceuticals in aquatic food webs have not been reported. In this study, bioaccumulation of select pharmaceuticals was investigated in a lower order effluent-dependent stream in central Texas, USA, using isotope dilution liquid chromatography–tandem mass spectrometry (MS). A fish plasma model, initially developed from laboratory studies, was tested to examine observed versus predicted internal dose of select pharmaceuticals. Pharmaceuticals accumulated to higher concentrations in invertebrates relative to fish; elevated concentrations of the antidepressant sertraline and its primary metabolite desmethylsertraline were observed in the Asian clam, Corbicula fluminea, and two unionid mussel species. Trophic positions were determined from stable isotopes (δ15N and δ13C) collected by isotope ratio-MS; a Bayesian mixing model was then used to estimate diet contributions towards top fish predators. Because diphenhydramine and carbamazepine were the only target compounds detected in all species examined, trophic magnification factors (TMFs) were derived to evaluate potential trophic transfer of both compounds. TMFs for diphenhydramine (0.38) and carbamazepine (1.17) indicated neither compound experienced trophic magnification, which suggests that inhalational and not dietary exposure represented the primary route of uptake by fish in this effluent-dependent stream. PMID:25313153

Evaluating mercury bioaccumulation rates in fish using mark-recapture techniques

NASA Astrophysics Data System (ADS)

Mathews, T.; Surendran Nair, S.; McManamay, R.

2017-12-01

Mercury (Hg) bioaccumulation can be described by models of varying complexity, from the simplified bioconcentration factor which describes the partitioning of contaminants between water and the organism, to more sophisticated models which take into consideration speciation, complexation, and/or bioavailability. At contaminated sites, especially those that are undergoing remediation, it is helpful to have a dynamic framework to identify critical Hg sources and processes, and to predict time scales to recovery. However, understanding the relationship between changes in exposure concentrations and bioaccumulation rates remains a challenge. East Fork Poplar Creek (EFPC) is a Hg-contaminated stream located in East Tennessee. Over the past 30 years, various remediation actions have succeeded in significantly reducing Hg inputs to this stream. One of the major goals of remediation is to reduce Hg bioaccumulation in resident sunfish in order to meet human health guidelines. Mercury is measured in sunfish fillets bi-annually at various sites along the stream. Because Hg analysis requires only 100 mg of tissue, fish can be sampled non-lethally and released at the site of capture. Since 2008, passive induced transponder (PIT) tags have been used to identify individual fish that are collected from EFPC for Hg analysis. Approximately 10% of PIT tagged fish were recaptured, allowing for the measurement of growth rates and Hg bioaccumulation rates in individual fish. While traditional biomonitoring studies conducted in EFPC have found that the average Hg concentrations in sacrificed fish have not responded to changes in aqueous Hg concentrations over the past 10 years, data from the mark-recapture study show that individual fish may respond to changes in aqueous inorganic Hg concentrations on shorter time scales. Rapid changes in aqueous Hg concentrations over a four year period resulted in measurable increases and decreases in Hg concentrations in individual fish that could not be explained by growth dilution. These findings are relevant to remediation decisions in EFPC and other Hg-contaminated sites.

Decadal stream water quality trends under varying climate, land use, and hydrogeochemical setting in, Iowa, USA

NASA Astrophysics Data System (ADS)

Green, Christopher; Bekins, Barbara; Kalkhoff, Stephen; Hirsch, Robert; Liao, Lixia; Barnes, Kimberlee

2015-04-01

Understanding how nitrogen fluxes respond to changes in agricultural practices and climatic variations is important for improving water quality in agricultural settings. In the central United States, intensification of corn cropping in support of ethanol production led to increases in N application rates in the 2000s during a period including both extreme dry and wet conditions. To examine the effect of these recent changes, a study was conducted on surface water quality in 10 major Iowa Rivers. Long term (~20 to 30 years) water quality and flow data were analyzed with Weighted Regression on Time, Discharge and Season (WRTDS), a statistical method that provides internally consistent estimates of the concentration history and reveals decadal trends that are independent of random variations of stream flow from seasonal averages. Trends of surface water quality showed constant or decreasing flow-normalized concentrations of nitrate+nitrite-N from 2000 to 2012 in all basins. To evaluate effects of annual discharge and N loading on these trends, multiple conceptual models were developed and calibrated to annual concentrations. The recent declining concentration trends can be attributed to both very high and very low streamflow discharge in the 2000's and to the long (e.g. 8-year) subsurface residence times in some basins. Dilution of surface water nitrate and depletion of stored nitrate may occur in years with very high discharge. Limited transport of N to streams and accumulation of stored N may occur in years with very low discharge. Central Iowa basins showed the greatest reduction in concentrations, likely because extensive tile-drains limit the effective volumes for storage of N and reduce residence times, and because the glacial sediments in these basins promote denitrification. Changes in nitrogen fluxes resulting from ethanol production and other factors will likely be delayed for years or decades in peripheral basins of Iowa, and may be obscured in the central basins where extreme flows strongly affect annual concentration trends.

Estimating gas exchange of CO2 and CH4 between headwater systems and the atmosphere in Southwest Sweden

NASA Astrophysics Data System (ADS)

Somlai, Celia; Natchimuthu, Sivakiruthika; Bastviken, David; Lorke, Andreas

2015-04-01

Quantifying the role of inland water systems in terms of carbon sinks and sources and their connection to the terrestrial ecosystems and landscapes is fundamental for improving the balance approach of regional and global carbon budgets. Recent research showed that freshwater bodies emit significant amounts of CO2 and CH4 into the atmosphere. The extent of the emissions from small streams and headwaters, however, remains uncertain due to a limited availability of data. Studies have shown that headwater systems receive most of the terrestrial organic carbon, have the highest dissolved CO2 concentration and the highest gas exchange velocities and cover the largest fractional surface area within fluvial networks. The gas exchange between inland waters and the atmosphere is controlled by two factors: the difference between the dissolved gas concentration and its atmospheric equilibrium concentration, and the gas exchange velocity. The direct measurement of the dissolved gas concentration of greenhouse gases can be measured straightforwardly, for example, by gas chromatography from headspace extraction of water sample. In contrast, direct measurement of gas exchange velocity is more complex and time consuming, as simultaneous measurements with a volatile and nonvolatile inert tracer gas are needed. Here we analyze measurements of gas exchange velocities, concentrations and fluxes of dissolved CO2 and CH4, as well as loads of total organic and inorganic carbon in 10 reaches in headwater streams in Southwest Sweden. We compare the gas exchange velocities measured directly through tracer injections with those estimated through various empirical approaches, which are based on modelled and measured current velocity, stream depth and slope. Furthermore, we estimate the resulting uncertainties of the flux estimates. We also present different time series of dissolved CO2, CH4 and O2 concentration, water temperature, barometric pressure, electro conductivity, and pH values measured during the period of tracer injection.

Nitrogen solutes in an Adirondack forested watershed: Importance of dissolved organic nitrogen

USGS Publications Warehouse

McHale, M.R.; Mitchell, M.J.; McDonnell, Jeffery J.; Cirmo, C.P.

2000-01-01

Nitrogen (N) dynamics were evaluated from 1 June 1995 through 31 May 1996 within the Arbutus Lake watershed in the Adirondack Mountains of New York State, U.S.A. At the Arbutus Lake outlet dissolved organic nitrogen (DON), NO3/- and NH4/+ contributed 61%, 33%, and 6% respectively, to the total dissolved nitrogen (TDN) flux (259 mol ha-1 yr-1). At the lake inlet DON, NO3/-, and NH4/+ constituted 36%, 61%, and 3% respectively, of TDN flux (349 mol ha-1 yr-1). Differences between the factors that control DON, NO3/-, and NH4+ stream water concentrations were evaluated using two methods for estimating annual N flux at the lake inlet. Using biweekly sampling NO3/- and NH4/+ flux was 10 and 4 mol ha-1 yr-1 respectively, less than flux estimates using biweekly plus storm and snowmelt sampling. DON flux was 18 mol ha-1 yr-1 greater using only biweekly sampling. These differences are probably not of ecological significance relative to the total flux of N from the watershed (349 mol ha-1 yr-1). Dissolved organic N concentrations were positively related to discharge during both the dormant (R2 = 0.31; P<0.01) and growing season (R2= 0.09; P<0.01). There was no significant relationship between NO3/- concentration and discharge during the dormant season, but a significant negative relationship was found during the growing season (R2 = 0.29; P<0.01). Biotic controls in the growing season appeared to have had a larger impact on stream water NO3- concentrations than on DON concentrations. Arbutus Lake had a major impact on stream water N concentrations of the four landscape positions sampled, suggesting the need to quantify within lake processes to interpret N solute losses and patterns in watershed-lake systems.

Effects of acidic precipitation on the water quality of streams in the Laurel Hill area, Somerset County, Pennsylvania, 1983-86

USGS Publications Warehouse

Barker, J.L.; Witt, E. C.

1990-01-01

Five headwater streams in the Laurel Hill area in southwestern Pennsylvania were investigated from September 1983 through February 1986 to determine possible effects of acidic precipitation on water quality. Precipitation in the Laurel Hill area is among the most acidic in the Nation, with a mean volume-weighted pH of 4.06. Sulfate is the dominant acid-forming anion, averaging 3.6 milligrams per liter or about 50 kilograms per hectare in wet deposition alone. Nitrate averages about 2 milligrams per liter or 7 kilograms per hectare in the study area. Stream chemistry in the five streams is quite variable and apparently is influenced to a large degree by the bedrock geology and by small amounts of alkaline material in watershed soils. Three of the five streams with no or little acid-neutralizing capacity presently are devoid of fish because of low pH and elevated aluminum concentrations. Aluminum concentrations increase in the other two streams during rainfall and snowmelt despite comparatively higher base flow and acid-neutralizing capacities. Comparison of the chemistry of streamflow during 14 storm events at South Fork Bens Creek and North Fork Bens Creek reveals similar chemical responses when discharge suddenly increases. Concentrations of dissolved metals and sulfate increased during stormflow and snowmelt runoff, whereas concentrations of base cations, silica, and chloride decreased. Nitrate concentrations were not affected by rainfall runoff by tended to increase with snowmelt runoff.

The effect of beaver ponds on water quality in rural coastal plain streams

USGS Publications Warehouse

Bason, Christopher W.; Kroes, Daniel; Brinson, Mark M.

2017-01-01

We compared water-quality effects of 13 beaver ponds on adjacent free-flowing control reaches in the Coastal Plain of rural North Carolina. We measured concentrations of nitrate, ammonium, soluble reactive phosphorus (SRP), and suspended sediment (SS) upstream and downstream of paired ponds and control reaches. Nitrate and SS concentrations decreased, ammonium concentrations increased, and SRP concentrations were unaffected downstream of the ponds and relative to the control reaches. The pond effect on nitrate concentration was a reduction of 112 ± 55 μg-N/L (19%) compared to a control-reach—influenced reduction of 28 ± 17 μg-N/L. The pond effect on ammonium concentration was an increase of 9.47 ± 10.9 μg-N/L (59%) compared to the control-reach—influenced reduction of 1.49 ± 1.37 μg-N/L. The pond effect on SS concentration was a decrease of 3.41 ± 1.68 mg/L (40%) compared to a control-reach—influenced increase of 0.56 ± 0.27 mg/L. Ponds on lower-order streams reduced nitrate concentrations by greater amounts compared to those in higher-order streams. Older ponds reduced SS concentrations by greater amounts compared to younger ponds. The findings of this study indicate that beaver ponds provide water-quality benefits to rural Coastal Plain streams by reducing concentrations of nitrate and suspended sediment.

Physical and biogeochemical controls on polymictic behavior in Sierra Nevada stream pools

NASA Astrophysics Data System (ADS)

Lucas, R. G.; Conklin, M. H.; Tyler, S. W.; Suarez, F. I.; Moran, J. E.; Esser, B. K.

2011-12-01

We observed polymictic behavior in stream pools in a low gradient montane meadow in the southern Sierra Nevada mountains, California. Thermal stratification in stream pools has been observed in various environments; stratification generally persists where the buoyancy forces created by a variation in water density, as a function of water temperature, are able to overcome turbulent forces resulting from stream flow. Because the density gradient creates a relatively weak buoyancy force, low flow conditions are generally required in order to overcome the turbulent forces. In some studies, a cold water source in to the pool bottoms can help to increase the density gradient and perpetuate thermal stratification. Our study took place in Long Meadow, Sequoia National Park, California. Long Meadow lies in the Wolverton Creek watershed and is part of the Southern Sierra Critical Zone Observatory. The 1-4 m diameter and 1-2 m deep pools in our study stratified thermally during the day and mixed completely at night. The low gradient of the meadow provided low stream flows. Piezometers in the meadow indicated groundwater discharge into the meadow in the months during which stratification was observed. Radon 222 activity measured in the pools also indicated groundwater influx to the pool bottoms. We used Fluent, a computational fluid dynamics equation solver, to construct a model of one of the observed pools. Initially we attempted to model the physical mechanisms controlling thermal stratification in the pool including stream flow, groundwater discharge, solar radiation, wind speed, and air, stream and ground water temperatures. Ultimately we found the model best agreed with our observed pool temperatures when we considered the light attenuation coefficients as a function of the dissolve organic carbon (DOC) concentration. Elevated DOC concentrations are expected in low stream flow regimes associated with highly organic soils such as a montane meadow. DOC concentrations measured in samples collected from the meadow stream, pools, and ground water wells ranged from 3.09 to 5.25 mg/L. We used a power equation taken from the literature to vary the visible light attenuation with DOC values measured in the meadow system. Light attenuation coefficients determined from measured DOC concentrations ranged from 0.507 m-1 to 0.899 m-1. The results from our modeling efforts indicate that in low flow streams and rivers elevated concentrations of DOC can increase the potential for thermal stratification in stream pools.

Impact of redox and transport processes in a riparian wetland on stream water quality in the Fichtelgebirge region, southern Germany

NASA Astrophysics Data System (ADS)

Lischeid, G.; Kolb, A.; Alewell, C.; Paul, S.

2007-01-01

Biologically mediated redox processes in the riparian zone, like denitrification, can have substantially beneficial impacts on stream water quality. The extent of these effects, however, depends greatly on the hydrological boundary conditions. The impact of hydrological processes on a wetland's nitrogen sink capacity was investigated in a forested riparian fen which is drained by a first-order perennial stream. Here, we analysed the frequency distributions and time-series of pH and nitrogen, silica, organic carbon and oxygen concentrations in throughfall, soil solution, groundwater and stream water, and the groundwater levels and stream discharges from a 3-year period. During baseflow conditions, the stream was fed by discharging shallow, anoxic groundwater and by deep, oxic groundwater. Whereas the latter delivered considerable amounts of nitrogen (0.37 mg l-1) to the stream, the former was almost entirely depleted of nitrogen. During stormflow, near-surface runoff in the upper 30 cm soil layer bypassed the denitrifying zone and added significant amounts to the nitrogen load of the stream. Nitrate-nitrogen was close to 100% of deep groundwater and stream-water nitrogen concentration. Stream-water baseflow concentrations of nitrate, dissolved carbon and silica were about 1.6 mg l-1, 4 mg l-1 and 7.5 mg l-1 respectively, and >3 mg l-1, >10 mg l-1 and <4 mg l-1 respectively during discharge peaks. In addition to that macroscale bypassing effect, there was evidence for a corresponding microscale effect: Shallow groundwater sampled by soil suction cups indicated complete denitrification and lacked any seasonal signal of solute concentration, which was in contrast to piezometer samples from the same depth. Moreover, mean solute concentration in the piezometer samples resembled more that of suction-cup samples from shallower depth than that of the same depth. We conclude that the soil solution cups sampled to a large extent the immobile soil-water fraction. In contrast, the mobile fraction that was sampled by the piezometers exhibited substantially shorter residence time, thus being less exposed to denitrification, but predominating discharge of that layer to the stream. Consequently, assessing the nitrogen budget based on suction-cup data tended to overestimate the nitrogen consumption in the riparian wetland. These effects are likely to become more important with the increased frequency and intensity of rainstorms that are expected due to climate change. Copyright

Persistent Influences of the 2002 Hayman Fire on Stream Nitrate and Dissolved Organic Carbon

NASA Astrophysics Data System (ADS)

Rhoades, C.; Pierson, D. N.; Fegel, T. S., II; Chow, A. T.; Covino, T. P.

2016-12-01

Large, high severity wildfires alter the physical and biological conditions that determine how watersheds retain and release nutrients and regulate stream water quality. For five years after the 2002 Hayman Fire burned in Colorado conifer forests, stream nitrate concentrations and export increased steadily in watersheds with extensive high-severity burning. Stream temperature and turbidity also increased in relation to the extent of high-severity burning and remained elevated above background levels throughout the initial five year post-fire period. Our recent sampling documents that 14 years after the Hayman Fire stream nitrate remains an order of magnitude higher in extensively-burned (35-90%) compared to unburned watersheds (0.2 vs 2.8 mg L-1). Nitrate represents 83% of the total dissolved N in extensively-burned watersheds compared to 29% in unburned watersheds. In contrast, dissolved organic carbon (DOC), was highest in watersheds that burned to a moderate extent (10-20%) and lowest in those with extensive burning. Catchments with a moderate extent burned had DOC concentrations 2.5 and 1.7 times more than those with extensive burning and unburned catchments, respectively. Peak concentrations of DOC and nitrate track the rising limb of the streamflow hydrograph and reach a maximum in May, but patterns among burn extent categories were seasonally consistent. Current riparian conditions are linked to stream nitrate in burned watersheds. For example, stream nitrate increases proportionally to the extent of riparian zones with low shrub cover (R2 = 0.76). We found signs of watershed recovery compared to the initial post-fire period; stream temperature and turbidity remained elevated in extensively burned catchments, but increases were only significant during the spring season. The persistent stream nitrate concentrations as well as the relation between riparian cover and post-fire stream nitrate may help prioritize restoration planting efforts and mitigate chronic, elevated nitrate export from burned watersheds.

Relating road salt to exceedances of the water quality standard for chloride in New Hampshire streams.

PubMed

Trowbridge, Philip R; Kahl, J Steve; Sassan, Dari A; Heath, Douglas L; Walsh, Edward M

2010-07-01

Six watersheds in New Hampshire were studied to determine the effects of road salt on stream water quality. Specific conductance in streams was monitored every 15 min for one year using dataloggers. Chloride concentrations were calculated from specific conductance using empirical relationships. Stream chloride concentrations were directly correlated with development in the watersheds and were inversely related to streamflow. Exceedances of the EPA water quality standard for chloride were detected in the four watersheds with the most development. The number of exceedances during a year was linearly related to the annual average concentration of chloride. Exceedances of the water quality standard were not predicted for streams with annual average concentrations less than 102 mg L(-1). Chloride was imported into three of the watersheds at rates ranging from 45 to 98 Mg Cl km(-2) yr(-1). Ninety-one percent of the chloride imported was road salt for deicing roadways and parking lots. A simple, mass balance equation was shown to predict annual average chloride concentrations from streamflow and chloride import rates to the watershed. This equation, combined with the apparent threshold for exceedances of the water quality standard, can be used for screening-level TMDLs for road salt in impaired watersheds.

Modeling the Factors Impacting Pesticide Concentrations in Groundwater Wells.

PubMed

Aisopou, Angeliki; Binning, Philip J; Albrechtsen, Hans-Jørgen; Bjerg, Poul L

2015-01-01

This study examines the effect of pumping, hydrogeology, and pesticide characteristics on pesticide concentrations in production wells using a reactive transport model in two conceptual hydrogeologic systems; a layered aquifer with and without a stream present. The pumping rate can significantly affect the pesticide breakthrough time and maximum concentration at the well. The effect of the pumping rate on the pesticide concentration depends on the hydrogeology of the aquifer; in a layered aquifer, a high pumping rate resulted in a considerably different breakthrough than a low pumping rate, while in an aquifer with a stream the effect of the pumping rate was insignificant. Pesticide application history and properties have also a great impact on the effect of the pumping rate on the concentration at the well. The findings of the study show that variable pumping rates can generate temporal variability in the concentration at the well, which helps understanding the results of groundwater monitoring programs. The results are used to provide guidance on the design of pumping and regulatory changes for the long-term supply of safe groundwater. The fate of selected pesticides is examined, for example, if the application of bentazone in a region with a layered aquifer stops today, the concentration at the well can continue to increase for 20 years if a low pumping rate is applied. This study concludes that because of the rapid response of the pesticide concentration at the drinking water well due to changes in pumping, wellhead management is important for managing pesticide concentrations. © 2014, National GroundWater Association.

Estimation of traveltime and longitudinal dispersion in streams in West Virginia

USGS Publications Warehouse

Wiley, Jeffrey B.; Messinger, Terence

2013-01-01

Traveltime and dispersion data are important for understanding and responding to spills of contaminants in waterways. The U.S. Geological Survey (USGS), in cooperation with West Virginia Bureau for Public Health, Office of Environmental Health Services, compiled and evaluated traveltime and longitudinal dispersion data representative of many West Virginia waterways. Traveltime and dispersion data were not available for streams in the northwestern part of the State. Compiled data were compared with estimates determined from national equations previously published by the USGS. The evaluation summarized procedures and examples for estimating traveltime and dispersion on streams in West Virginia. National equations developed by the USGS can be used to predict traveltime and dispersion for streams located in West Virginia, but the predictions will be less accurate than those made with graphical interpolation between measurements. National equations for peak concentration, velocity of the peak concentration, and traveltime of the leading edge had root mean square errors (RMSE) of 0.426 log units (127 percent), 0.505 feet per second (ft/s), and 3.78 hours (h). West Virginia data fit the national equations for peak concentration, velocity of the peak concentration, and traveltime of the leading edge with RMSE of 0.139 log units (38 percent), 0.630 ft/s, and 3.38 h, respectively. The national equation for maximum possible velocity of the peak concentration exceeded 99 percent and 100 percent of observed values from the national data set and West Virginia-only data set, respectively. No RMSE was reported for time of passage of a dye cloud, as estimated using the national equation; however, the estimates made using the national equations had a root mean square error of 3.82 h when compared to data gathered for this study. Traveltime and dispersion estimates can be made from the plots of traveltime as a function of streamflow and location for streams with plots available, but estimates can be made using the national equations for streams without plots. The estimating procedures are not valid for regulated stream reaches that were not individually studied or streamflows outside the limits studied. Rapidly changing streamflow and inadequate mixing across the stream channel affect traveltime and dispersion, and reduce the accuracy of estimates. Increases in streamflow typically result in decreases in the peak concentration and traveltime of the peak concentration. Decreases in streamflow typically result in increases in the peak concentration and traveltime of the peak concentration. Traveltimes will likely be less than those determined using the estimating equations and procedures if the spill is in the center of the stream, and traveltimes will likely be greater than those determined using the estimating equations and procedures if the spill is near the streambank.

Groundwater-surface water interaction in the riparian zone of an incised channel, Walnut Creek, Iowa

USGS Publications Warehouse

Schilling, K.E.; Li, Z.; Zhang, Y.-K.

2006-01-01

Riparian zones of many incised channels in agricultural regions are cropped to the channel edge leaving them unvegetated for large portions of the year. In this study we evaluated surface and groundwater interaction in the riparian zone of an incised stream during a spring high flow period using detailed stream stage and hydraulic head data from six wells, and water quality sampling to determine whether the riparian zone can be a source of nitrate pollution to streams. Study results indicated that bank storage of stream water from Walnut Creek during a large storm water runoff event was limited to a narrow 1.6 m zone immediately adjacent to the channel. Nitrate concentrations in riparian groundwater were highest near the incised stream where the unsaturated zone was thickest. Nitrate and dissolved oxygen concentrations and nitrate-chloride ratios increased during a spring recharge period then decreased in the latter portion of the study. We used MODFLOW and MT3DMS to evaluate dilution and denitrification processes that would contribute to decreasing nitrate concentrations in riparian groundwater over time. MT3DMS model simulations were improved with a denitrification rate of 0.02 1/d assigned to the floodplain sediments implying that denitrification plays an important role in reducing nitrate concentrations in groundwater. We conclude that riparian zones of incised channels can potentially be a source of nitrate to streams during spring recharge periods when the near-stream riparian zone is largely unvegetated. ?? 2005 Elsevier B.V. All rights reserved.

Mercury transport in a high-elevation watershed in Rocky Mountain National Park, Colorado

USGS Publications Warehouse

Mast, M.A.; Campbell, D.H.; Krabbenhoft, D.P.; Taylor, Howard E.

2005-01-01

Mercury (Hg) was measured in stream water and precipitation in the Loch Vale watershed in Rocky Mountain National Park, Colorado, during 2001-2002 to investigate processes controlling Hg transport in high-elevation ecosystems. Total Hg concentrations in precipitation ranged from 2.6 to 36.2 ng/L and showed a strong seasonal pattern with concentrations that were 3 to 4 times higher during summer months. Annual bulk deposition of Hg was 8.3 to 12.4 ?? g/m 2 and was similar to deposition rates in the Midwestern and Northeastern U.S. Total Hg concentrations in streams ranged from 0.8 to 13.5 ng/L and were highest in mid-May on the rising limb of the snowmelt hydrograph. Stream-water Hg was positively correlated with dissolved organic carbon suggesting organically complexed Hg was flushed into streams from near-surface soil horizons during the early stages of snowmelt. Methylmercury (MeHg) in stream water peaked at 0.048 ng/L just prior to peak snowmelt but was at or below detection (< 0.040 ng/L) for the remainder of the snowmelt season. Annual export of total Hg in Loch Vale streams ranged from 1.2 to 2.3 ?? g/m2, which was less than 20% of wet deposition, indicating the terrestrial environment is a net sink of atmospheric Hg. Concentrations of MeHg in stream water and corresponding watershed fluxes were low, indicating low methylation rates or high demethylation rates or both. ?? Springer 2005.

Variation in stream diatom communities in relation to water quality and catchment variables in a boreal, urbanized region.

PubMed

Teittinen, Anette; Taka, Maija; Ruth, Olli; Soininen, Janne

2015-10-15

Intensive anthropogenic land use such as urbanization alters the hydrological cycle, water chemistry and physical habitat characteristics, thus impairing stream physicochemical and biological quality. Diatoms are widely used to assess stream water quality as they integrate water chemistry temporally and reflect the joint influence of multiple stressors on stream biota. However, knowledge of the major community patterns of diatoms in urban streams remains limited especially in boreal regions. The aim of this study was to examine the effects of water chemistry and catchment characteristics on stream diatom communities, and to test the performance of the Index of Pollution Sensitivity (IPS) as a stream water quality indicator across an urban-to-rural gradient in southern Finland. Diatom community structure and species richness were related to local-scale variables such as water temperature, aluminium concentration, and electrical conductivity, which were in turn influenced by patterns in catchment land use and land cover. Diatoms reflected the intensity of human activities as more intensive land use increased the occurrence of pollution-tolerant species. The change in community structure along the land use intensity gradient was accompanied by a distinct decline in species richness. On the contrary, the IPS index failed to indicate differences in water quality along the urban-to-rural gradient as no consistent differences in the IPS values were found. Our results highlight the joint influence of multifaceted factors that underlie diatom patterns, and show that diatom biodiversity can be used as cost-effective metric indicating urban stream conditions. However, the IPS index turned out to be an unsuitable tool for assessing water quality among these streams. Copyright © 2015 Elsevier B.V. All rights reserved.

Use of Artificial Neural Networks to Examine Parameters Affecting the Immobilization of Streptokinase in Chitosan

PubMed Central

Modaresi, Seyed Mohamad Sadegh; Faramarzi, Mohammad Ali; Soltani, Arash; Baharifar, Hadi; Amani, Amir

2014-01-01

Streptokinase is a potent fibrinolytic agent which is widely used in treatment of deep vein thrombosis (DVT), pulmonary embolism (PE) and acute myocardial infarction (MI). Major limitation of this enzyme is its short biological half-life in the blood stream. Our previous report showed that complexing streptokinase with chitosan could be a solution to overcome this limitation. The aim of this research was to establish an artificial neural networks (ANNs) model for identifying main factors influencing the loading efficiency of streptokinase, as an essential parameter determining efficacy of the enzyme. Three variables, namely, chitosan concentration, buffer pH and enzyme concentration were considered as input values and the loading efficiency was used as output. Subsequently, the experimental data were modeled and the model was validated against a set of unseen data. The developed model indicated chitosan concentration as probably the most important factor, having reverse effect on the loading efficiency. PMID:25587327

Regulation of the dissolved phosphate concentration of a mountainous stream, Kitakyushu, southwestern Japan.

PubMed

Koga, Masaaki; Yoshimura, Kazuhisa

2012-07-01

The phosphate concentration in mountainous stream water can be a measure of the forest condition, because its concentration will be low when the biomass in the forest is increasing and vice versa when the forest is declining. To investigate the seasonal change in the dissolved phosphate concentration of the mountainous stream water of the Yamakami River, Kitakyushu, from June 2009 to August 2010, and the regulation mechanism of the phosphate concentration, solid-phase spectrophotometry, which can be applicable to natural water without any pretreatment procedures, was employed for the determination of phosphate at μg P L(-1) levels in natural water. The phosphate concentrations in the mountainous stream waters at 6 sites ranged from 2.2 to 13 μg P L(-1), and those from the catchment area of the steady state forest were 5.3 ± 1.6 (±1 SD) μg P L(-1). Changes in the concentration were fairly small even during a storm runoff. The average phosphate concentration of rain was 2.8 ± 0.7 μg P L(-1), about half of the concentration in the stream water. The rate of runoff in forest areas is generally considered to be about 50% of the total precipitation. For a forest under a climax condition, the phosphate concentration is estimated to be regulated by the fallout and evapotranspiration (α = 0.05). At one of the sites, an upstream tributary, where a fairly big landslide occurred before July in 2009, the phosphate concentration was the highest, suggesting that the biomass may still be decreasing. For all of the six sites examined, a characteristic seasonal change in phosphate concentration was observed, reflecting the local budget between the biological decomposition of plant matter and the consumption by the biomass. The increase in the phosphate concentration during late spring and early summer may result from the extensive decomposition of plant litter mainly supplied in autumn and of plant matter relating to spring blooming such as fallen flowers, pollen and immature fruits. The proposed method using the phosphate concentration in surface stream waters without the period of the seasonal change mentioned above is expected to be very helpful in diagnosing the condition of forests.

The response of hydrophobic organics and potential toxicity in streams to urbanization of watersheds in six metropolitan areas of the United States

USGS Publications Warehouse

Bryant, W.L.; Goodbred, S.L.

2009-01-01

Semipermeable membrane devices (SPMDs) were deployed in streams along a gradient of urban land-use intensity in and around six metropolitan areas: Atlanta, Georgia; Raleigh - Durham, North Carolina; and Denver - Fort Collins, Colorado, in 2003; and Dallas - Fort Worth, Texas; Milwaukee - Green Bay, Wisconsin; and Portland, Oregon, in 2004 to examine relations between percent urban land cover in watersheds and the occurrence, concentrations, and potential toxicity of hydrophobic compounds. Of the 142 endpoints measured in SPMD dialysates, 30 were significantly (alpha = 0.05) related to the percent of urban land cover in the watersheds in at least one metropolitan area. These 30 endpoints included the aggregated measures of the total number of compounds detected and relative toxicity (Microtox?? and P450RGS assays), in addition to the concentrations of 27 individual hydrophobic compounds. The number of compounds detected, P450RGS assay values, and the concentrations of pyrogenic polycyclic aromatic hydrocarbons (PAHs) were significantly related to percent urban land cover in all six metropolitan areas. Pentachloroanisole, the most frequently detected compound, was significantly related to urban land cover in all metropolitan areas except Dallas - Fort Worth. Petrogenic PAHs and dibenzofurans were positively related to percent urban land cover in Atlanta, Raleigh - Durham, Denver, and Milwaukee - Green Bay. Results for other endpoints were much more variable. The number of endpoints significantly related to urban land cover ranged from 6 in Portland to 21 Raleigh-Durham. Based on differences in the number and suite of endpoints related to urban intensity, these results provide evidence of differences in factors governing source strength, transport, and/or fate of hydrophobic compounds in the six metropolitan areas studied. The most consistent and significant results were that bioavailable, aryl hydrocarbon receptor agonists increase in streams as basins become urbanized. Potential toxicity mediated by this metabolic pathway is indicated as an important factor in the response of aquatic biota to urbanization. ?? Springer Science+Business Media B.V. 2008.

Is Nitrogen Deposition Altering the Nitrogen Status of Northeastern Forests?

NASA Astrophysics Data System (ADS)

Aber, J. D.; Goodale, C. L.; Ollinger, S. V.; Smith, M.; Magill, A. H.; Martin, M. E.; Hallett, R. A.; Stoddard, J. L.; Participants, N.

2002-05-01

The nitrogen saturation hypothesis suggests that foliar and soil N concentration, nitrification rate, and nitrate leaching loss should all increase in response to increased N deposition. We tested this hypothesis with a major new synthesis of foliar (362 plots), soil (251 plots), and surface water (354 lakes and streams) chemistry from the northeastern U.S. Nitrogen deposition decreases across the Northeast from ~ 10-12 kg ha-1 yr-1 in the Mid-Atlantic region to ~ 4 kg ha-1 yr-1 in northern Maine. Foliar chemistry (%N and lignin:N ratio) of red spruce and sugar maple correlated more strongly with elevation than with N deposition, although these factors covary. Forest floor C:N ratio decreased with N deposition for both conifers and hardwoods although correlations were not strong (R2 < 0.20). Regardless of forest type or soil horizon, percent nitrification (as a fraction of N mineralization) increased as soil C:N decreased below ~25, and increased weakly with N deposition in hardwood stands. Across the Northeast, surface water seasonal nitrate concentrations and N export during the mid- to late-1990s increased with N deposition (R2 = 0.30-0.56), with two important patterns emerging: 1) nitrate rarely exceeded 1 μ mol/L in watersheds receiving <8-10 kg ha-1 yr-1; and 2) high nitrate concentrations occurred only in lakes and streams receiving relatively high N inputs. This pattern resembles that for European forests. Factors such as species composition, forest history, climate, and hydrology may affect foliar, soil, and stream chemistry at different spatial and temporal scales. Foliar and soil chemistry may be more strongly influenced by local heterogeneity, whereas surface water samples integrate over much larger areas. Using surface waters as the most comprehensive indicator of N saturation, it appears that N deposition is altering the N status of forests in the northeastern U.S.

Total Mercury and Methylmercury in the Great Egg Harbor River Watershed, New Jersey, USA

NASA Astrophysics Data System (ADS)

Barringer, J. L.; Riskin, M. L.; Szabo, Z.; Fischer, J. M.; Reilly, P. A.; Rosman, R.; Bonin, J. L.; Heckathorn, H. A.

2007-12-01

Hydrologic and biogeochemical conditions are important factors in the transport and distribution of mercury (Hg) in New Jersey Coastal Plain watersheds that contain extensive freshwater wetlands and where Hg bioaccumulation is of concern. U.S. Geological Survey studies found Hg concentrations in top predator fish from the Great Egg Harbor River mainstem that ranged from 2.9 to 4.5 mg/kg (dry wt.) and exceeded 10 ng/L in the watershed's acidic streams. An ongoing study with the N.J. Department of Environmental Protection indicates that atmospheric deposition of Hg to the wetlands and streams may be augmented by substantial contributions of Hg from ground water. Although background levels of Hg in water from the underlying aquifer typically are less than 10 ng/L, concentrations in water from more than 600 domestic wells in southern New Jersey have been shown to exceed the drinking-water maximum contaminant level of 2,000 ng/L. Therefore, to determine ground-water inputs to the streams, samples of ground water discharging to the tributaries and mainstem as well as streamwater samples collected during various flow conditions were analyzed for total Hg and methylmercury (MeHg). Total Hg concentrations in ground water discharging to the tributaries and mainstem were low to moderate (0.29-22 ng/L) in relatively undeveloped areas (including wetlands), but higher (36 and 177 ng/L) in two urban/suburban areas where much of the Hg was in particulate form. In recent and ongoing studies, total Hg concentrations in unfiltered samples of surface water, except those for one suburban tributary, have ranged from 2.13 to 37.7 ng/L. Concentrations in the suburban tributary have ranged from 50 ng/L during a dry period to 250 ng/L during a wet period. Hg concentrations in samples from a wetlands-embedded reach of the mainstem varied markedly with flow. In addition to increases in concentrations of total Hg, UV absorbance and concentrations of dissolved organic carbon also increased with flow after rain events, whereas pH and concentrations of dissolved oxygen and nitrate decreased. These flow-related changes apparently result from inputs of water that has percolated through acidic, reducing wetlands soils. The biogeochemical environment of these soils, on the basis of hydrogen sulfide odors detected during piezometer placement, supports sulfate reduction and likely promotes methylation of Hg. MeHg concentrations were 0.48 ng/L after a rainfall in discharge from 0.8 m below the streambed at a mainstem wetlands site. Downstream, where the channel briefly emerges from wetlands, MeHg was detectable during a dry period only in the hyporheic-zone water from 0.15 m below the streambed and in ground water from a depth of 0.3 m (0.15 ng/L and 0.05 ng/L, respectively). MeHg was not detected in the ground-water samples from deeper points below the streambeds, but concentrations in surface water ranged from 0.17 to 2.88 ng/L. The concentration from a tributary surrounded by urban/suburban development was highest. MeHg concentrations in mainstem water did not always increase with streamflow; variations in antecedent hydrologic conditions in the wetlands may explain the unpredictable relation of concentration to flow. Overall, total Hg appears to be contributed to the streams by both ground water and atmospheric deposition, with methylation taking place at shallow levels in wetlands soils and stream sediments.

Periphyton response to long-term nutrient enrichment in a shaded headwater stream

Treesearch

Jennifer L. Greenwood; Amy D. Rosemond

2009-01-01

We maintained elevated but moderate concentrations of nitrogen and phosphorus continuously for 2 years in a heavily shaded headwater stream and compared effects on stream periphyton with a reference...

Carbon-Isotopic Dynamics of Streams, Taylor Valley, Antarctica: Biological Effects

NASA Technical Reports Server (NTRS)

Neumann, K.; DesMarais, D. J.

1998-01-01

We have investigated the role of biological processes in the C-isotopic dynamics of the aquatic ecosystems in Taylor Valley, Antarctica. This cold desert ecosystem is characterized by the complete lack of vascular plants, and the presence of algal mats in ephemeral streams and perennially ice covered lakes. Streams having abundant algal mats and mosses have very low sigma CO2 concentrations, as well as the most depleted delta C-13 values (-4%). Previous work has shown that algal mats in these streams have delta C-13 values averaging -7.01%. These values are similar to those observed in the algal mats in shallow areas of the lakes in Taylor Valley, where CO2 is thought to be colimiting to growth. These low Sigma CO2 concentrations, and delta C(13) signatures heavier than the algal mats, suggest that CO2 may be colimiting in the streams, as well. Streams with little algal growth, especially the longer ones in Fryxell Basin, have higher Sigma CO2 concentrations and much more enriched isotopic signatures (as high as +8%). In these streams, the dissolution of isotopically enriched, cryogenic CaCO3 is probably the major source of dissolved carbonate. The delta C(13) geochemistry of Antarctic streams is radically different from the geochemistry of more temperate streams, as it is not affected by terrestrially produced, isotopically depleted Sigma CO2. These results have important implications for the understanding of "biogenic" carbonate that might have been produced from aquatic ecosystems in the past on Mars.

Causes of acidification of four streams on Laurel Hilld in southwestern Pennsylvania

USGS Publications Warehouse

Sharpe, William E.; DeWalle, David R.; Leibfried, Robert T.; Dinicola, Richard S.; Kimmel, William G.; Sherwin, Lysle S.

1984-01-01

Atmospheric deposition, soils developed from bedrock, a natural bog, gas wells, and a ski area were all investigated as possible sources of water quality degradation for four streams on Laurel Hill in southwestern Pennsylvania where fish kills have been reported since 1960. An intensive study of the chemistry of atmospheric deposition, soil leachate, and stream water and fish populations was conducted on these basins during 1980–1981 with emphasis on dormant season periods with runoff from snowmelt and rain. Although bedrock geology was found to control the natural buffering capacity of these streams, only acid precipitation could be linked to sharp drops in pH and increases in total Al concentrations observed during stormflows in the poorly buffered streams. Three poorly buffered streams exhibited drops to pH 4.4 to 4.5 and increases in total Al concentrations up to 1.5 mg/L during observed peak flows. Mineral soil leachate from the three major soil series on the basins during this time exhibited a low pH of 4.3 and mean total Al concentrations of 3.6 mg/L, indicating stream response during storms was closely linked to chemistry of soil leachate. Poorly buffered streams did not support reproducing populations of trout (Salmonidae sp.) or other fishes. In contrast, one well-buffered stream (20 mg/L CaCO3) exhibited drops to pH 5.5 during peak flow and supported reproducing trout and sculpin (Cottus bairdi) populations. The acidification of the four streams studied was attributed to atmospheric deposition.

Ecological risk assessment of zinc from stormwater runoff to an aquatic ecosystem.

PubMed

Brix, Kevin V; Keithly, James; Santore, Robert C; DeForest, David K; Tobiason, Scott

2010-03-15

Zinc (Zn) risks from stormwater runoff to an aquatic ecosystem were studied. Monitoring data on waterborne, porewater, and sediment Zn concentrations collected at 20 stations throughout a stormwater collection/detention facility consisting of forested wetlands, a retention pond and first order stream were used to conduct the assessment. Bioavailability in the water column was estimated using biotic ligand models for invertebrates and fish while bioavailability in the sediment was assessed using acid volatile sulfide-simultaneously extracted metal (AVS-SEM). The screening level assessment indicated no significant risks were posed to benthic organisms from Zn concentrations in sediments and pore water. As would be expected for stormwater, Zn concentrations were temporally quite variable within a storm event, varying by factors of 2 to 4. Overall, probabilistic assessment indicated low (5-10% of species affected) to negligible risks in the system, especially at the discharge to the first order stream. Moderate to high risks (10-50% of species affected) were identified at sampling locations most upgradient in the collection system. The largest uncertainty with the assessment is associated with how best to estimate chronic exposure/risks from time-varying exposure concentrations. Further research on pulse exposure metal toxicity is clearly needed to assess stormwater impacts on the environment.

Relative effect of temperature and pH on diel cycling of dissolved trace elements in prickly pear creek, Montana

USGS Publications Warehouse

Jones, Clain A.; Nimick, D.A.; McCleskey, R. Blaine

2004-01-01

Diel (24 hr) cycles in dissolved metal and As concentrations have been documented in many northern Rocky Mountain streams in the U.S.A. The cause(s) of the cycles are unknown, although temperature- and pH-dependent sorption reactions have been cited as likely causes. A light/dark experiment was conducted to isolate temperature and pH as variables affecting diel metal cycles in Prickly Pear Creek, Montana. Light and dark chambers containing sediment and a strand of macrophyte were placed in the stream to simulate instream temperature oscillations. Photosynthesis-induced pH changes were allowed to proceed in the light chambers while photosynthesis was prevented in the dark chambers. Water samples were collected periodically for 22 hr in late July 2001 from all chambers and the stream. In the stream, dissolved Zn concentrations increased by 300% from late afternoon to early morning, while dissolved As concentrations exhibited the opposite pattern, increasing 33% between early morning and late afternoon. Zn and As concentrations in the light chambers showed similar, though less pronounced, diel variations. Conversely, Zn and As concentrations in the dark chambers had no obvious diel variation, indicating that light, or light-induced reactions, caused the variation. Temperature oscillations were nearly identical between light and dark chambers, strongly suggesting that temperature was not controlling the diel variations. As expected, pH was negatively correlated (P < 0.01) with dissolved Zn concentrations and positively correlated with dissolved As concentrations in both the light and dark chambers. From these experiments, photosynthesis-induced pH changes were determined to be the major cause of the diel dissolved Zn and As cycles in Prickly Pear Creek. Further research is necessary in other streams to verify that this finding is consistent among streams having large differences in trace-element concentrations and mineralogy of channel substrate. ?? 2004 Kluwer Academic Publishers.

Diel behavior of rare earth elements in a mountain stream with acidic to neutral pH

USGS Publications Warehouse

Gammons, C.H.; Wood, S.A.; Nimick, D.A.

2005-01-01

Diel (24-h) changes in concentrations of rare earth elements (REE) were investigated in Fisher Creek, a mountain stream in Montana that receives acid mine drainage in its headwaters. Three simultaneous 24-h samplings were conducted at an upstream station (pH = 3.3), an intermediate station (pH = 5.5), and a downstream station (pH = 6.8). The REE were found to behave conservatively at the two upstream stations. At the downstream station, REE partitioned into suspended particles to a degree that varied with the time of day, and concentrations of dissolved REE were 2.9- to 9.4-fold (190% to 830%) higher in the early morning vs. the late afternoon. The decrease in dissolved REE concentrations during the day coincided with a corresponding increase in the concentration of REE in suspended particles, such that diel changes in the total REE concentrations were relatively minor (27% to 55% increase at night). Across the lanthanide series, the heavy REE partitioned into the suspended solid phase to a greater extent than the light REE. Filtered samples from the downstream station showed a decrease in shale-normalized REE concentration across the lanthanide series, with positive anomalies at La and Gd, and a negative Eu anomaly. As the temperature of the creek increased in the afternoon, the slope of the REE profile steepened and the magnitude of the anomalies increased. The above observations are explained by cyclic adsorption of REE onto suspended particles of hydrous ferric and aluminum oxides (HFO, HAO). Conditional partition coefficients for each REE between the suspended solids and the aqueous phase reached a maximum at 1700 hours and a minimum at 0700 hours. This pattern is attributed to diel variations in stream temperature, possibly reinforced by kinetic factors (i.e., slower rates of reaction at night than during the day). Estimates of the enthalpy of adsorption of each REE onto suspended particles based on the field results averaged +82 kJ/mol and are similar in magnitude to estimates in the literature for adsorption of divalent metal cations onto clays and hydrous metal oxides. The results of this study have important implications to the use of REE as hydrogeochemical tracers in streams. Copyright ?? 2005 Elsevier Ltd.

Relationship between structural features and water chemistry in boreal headwater streams--evaluation based on results from two water management survey tools suggested for Swedish forestry.

PubMed

Lestander, Ragna; Löfgren, Stefan; Henrikson, Lennart; Ågren, Anneli M

2015-04-01

Forestry may cause adverse impacts on water quality, and the forestry planning process is a key factor for the outcome of forest operation effects on stream water. To optimise environmental considerations and to identify actions needed to improve or maintain the stream biodiversity, two silvicultural water management tools, BIS+ (biodiversity, impact, sensitivity and added values) and Blue targeting, have been developed. In this study, we evaluate the links between survey variables, based on BIS+ and Blue targeting data, and water chemistry in 173 randomly selected headwater streams in the hemiboreal zone. While BIS+ and Blue targeting cannot replace more sophisticated monitoring methods necessary for classifying water quality in streams according to the EU Water Framework Directive (WFD, 2000/60/EC), our results lend support to the idea that the BIS+ protocol can be used to prioritise the protection of riparian forests. The relationship between BIS+ and water quality indicators (concentrations of nutrients and organic matter) together with data from fish studies suggests that this field protocol can be used to give reaches with higher biodiversity and conservation values a better protection. The tools indicate an ability to mitigate forestry impacts on water quality if the operations are adjusted to this knowledge in located areas.

The Role of Stream Water Carbon Dynamics and Export in the Carbon Balance of a Tropical Seasonal Rainforest, Southwest China

PubMed Central

Zhou, Wen-Jun; Zhang, Yi-Ping; Schaefer, Douglas A.; Sha, Li-Qing; Deng, Yun; Deng, Xiao-Bao; Dai, Kai-Jie

2013-01-01

A two-year study (2009 ∼ 2010) was carried out to investigate the dynamics of different carbon (C) forms, and the role of stream export in the C balance of a 23.4-ha headwater catchment in a tropical seasonal rainforest at Xishuangbanna (XSBN), southwest China. The seasonal volumetric weighted mean (VWM) concentrations of total inorganic C (TIC) and dissolved inorganic C (DIC) were higher, and particulate inorganic C (PIC) and organic C (POC) were lower, in the dry season than the rainy season, while the VWM concentrations of total organic C (TOC) and dissolved organic C (DOC) were similar between seasons. With increased monthly stream discharge and stream water temperature (SWT), only TIC and DIC concentrations decreased significantly. The most important C form in stream export was DIC, accounting for 51.8% of the total C (TC) export; DOC, POC, and PIC accounted for 21.8%, 14.9%, and 11.5% of the TC export, respectively. Dynamics of C flux were closely related to stream discharge, with the greatest export during the rainy season. C export in the headwater stream was 47.1 kg C ha−1 yr−1, about 2.85% of the annual net ecosystem exchange. This finding indicates that stream export represented a minor contribution to the C balance in this tropical seasonal rainforest. PMID:23437195

The role of stream water carbon dynamics and export in the carbon balance of a tropical seasonal rainforest, southwest China.

PubMed

Zhou, Wen-Jun; Zhang, Yi-Ping; Schaefer, Douglas A; Sha, Li-Qing; Deng, Yun; Deng, Xiao-Bao; Dai, Kai-Jie

2013-01-01

A two-year study (2009 ~ 2010) was carried out to investigate the dynamics of different carbon (C) forms, and the role of stream export in the C balance of a 23.4-ha headwater catchment in a tropical seasonal rainforest at Xishuangbanna (XSBN), southwest China. The seasonal volumetric weighted mean (VWM) concentrations of total inorganic C (TIC) and dissolved inorganic C (DIC) were higher, and particulate inorganic C (PIC) and organic C (POC) were lower, in the dry season than the rainy season, while the VWM concentrations of total organic C (TOC) and dissolved organic C (DOC) were similar between seasons. With increased monthly stream discharge and stream water temperature (SWT), only TIC and DIC concentrations decreased significantly. The most important C form in stream export was DIC, accounting for 51.8% of the total C (TC) export; DOC, POC, and PIC accounted for 21.8%, 14.9%, and 11.5% of the TC export, respectively. Dynamics of C flux were closely related to stream discharge, with the greatest export during the rainy season. C export in the headwater stream was 47.1 kg C ha(-1) yr(-1), about 2.85% of the annual net ecosystem exchange. This finding indicates that stream export represented a minor contribution to the C balance in this tropical seasonal rainforest.

Concentration-discharge relationships in headwater streams of the Sierra Nevada, California

Treesearch

Carolyn T. Hunsaker; Dale W. Johnson

2017-01-01

We examined streamwater concentration-discharge relationships for eight small, forest watersheds ranging in elevation from 1,485 to 2,465 m in the southern Sierra Nevada. These headwater streams revealed nearly chemostatic behavior by current definitions for K+, Ca...

Fate of acetone in an outdoor model stream with a nitrate supplement, southern Mississippi, U.S.A.

USGS Publications Warehouse

Rathbun, R.E.; Stephens, D.W.; Tai, D.Y.

1991-01-01

The fate of acetone in an outdoor model stream to which nitrate was added as a nutrient supplement was determined. The stream, in southern Mississippi, U.S.A. was 234 m long. Water was supplied to the stream by an artesian well at about 1.21 s-1, resulting in a mean water velocity of about 0.5 m min-1. Acetone was injected continuously for 26 days resulting in concentrations of 20-40 mg l-1. A nitrate solution was injected for 21 days resulting in an instream concentration of about 1.7 mg l-1 at the upstream end of the stream. Rhodamine-WT dye was used to determine the travel time and dispersion characteristics of the stream, and t-butyl alcohol was used to determine the volatilization characteristics. Volatilization controlled the fate of acetone in the model stream. The lack of substantial bacterial degradation of acetone was contrary to expectations based on the results of laboratory degradation studies using model stream water enriched with nitrate. A possible explanation for the lack of significant degradation in the model stream may be the limited 6-h residence time of the acetone in the stream. ?? 1991.

Bioavailability of Dissolved Organic Carbon and Nitrogen From Tropical Montane Rainforest Streams Across a Geologic age Gradient

NASA Astrophysics Data System (ADS)

Wiegner, T. N.

2005-05-01

Dissolved organic matter (DOM) is metabolically important in streams. Its bioavailability is influenced by organic matter sources to streams and inorganic nutrient availability. As forest canopies and soils develop over time, organic matter inputs to streams should switch from algal to watershed sources. Across this succession gradient, nutrient limitation should also change. This study examines how chemical composition and bioavailability of DOM from tropical montane rainforest streams on Hawaii change across a geologic age gradient from 4 ky to 150 ky. Dissolved organic C (DOC) and N (DON) concentrations, chemical characteristics, and bioavailability varied with site age. With increasing stream age, DOC and DON concentrations, DOM aromaticity, and the C:N of the stream DOM increased. Changes in stream DOM chemistry and inorganic nutrient availability affected DOM bioavailability. Fifty percent of the DOC from the 4 ky site was bioavailable, where little to none was bioavailable from the older streams. Inorganic nutrient availability did not affect DOC bioavailability. In contrast, DON bioavailability was similar (12%) across sites and was affected by inorganic nutrient availability. This study demonstrates that the chemistry and metabolism of streams draining forests change with ecosystem age and development.

Integrated assessment of sources, chemical stressors and stream quality along a groundwater fed stream system

NASA Astrophysics Data System (ADS)

Løgstrup Bjerg, Poul; Sonne, Anne T.; Rønde, Vinni; McKnight, Ursula S.

2016-04-01

Streams are impacted by significant contamination at the catchment scale, as they are often locations of multiple chemical stressor inputs. The European Water Framework Directive requires EU member states to ensure good chemical and ecological status of surface water bodies by 2027. This requires monitoring of stream water quality, comparison with environmental quality standards (EQS) and assessment of ecological status. However, the achievement of good status of stream water also requires a strong focus on contaminant sources, pathways and links to stream water impacts, so source management and remedial measures can be implemented. Fate and impacts of different contaminant groups are governed by different processes and are dependent on the origin (geogenic, anthropogenic), source type (point or diffuse) and pathway of the contaminant. To address this issue, we identified contaminant sources and chemical stressors on a groundwater-fed stream to quantify the contaminant discharges, link the chemical impact and stream water quality and assess the main chemical risk drivers in the stream system potentially driving ecological impact. The study was conducted in the 8 m wide Grindsted stream (Denmark) along a 16 km stream stretch that is potentially impacted by two contaminated sites (Grindsted Factory site, Grindsted Landfill), fish farms, waste water discharges, and diffuse sources from agriculture and urban areas. Water samples from the stream and the hyporheic zone as well as bed sediment samples were collected during three campaigns in 2012 and 2014. Data for xenobiotic organic groundwater contaminants, pesticides, heavy metals, general water chemistry, physical conditions and stream flow were collected. The measured chemical concentrations were converted to toxic units (TU) based on the 48h acute toxicity tests with D. magna. The results show a substantial impact of the Grindsted Factory site at a specific stretch of the stream. The groundwater plume caused elevated concentrations of chlorinated ethenes, benzene and site specific pharmaceuticals in both the hyporheic zone and the stream water. Observed stream water vinyl chloride concentrations (up to 6 μg/L) are far above the Danish EQS (0.05 μg/L) for several km downstream of the discharge area. For heavy metals, comparison with EQS in stream water, the hyporheic zone and streambed showed concentrations around or above the threshold values for barium, copper, lead, nickel and zinc. The calculated TU was generally similar along the stream, but for arsenic and nickel higher values were observed where the groundwater plume discharges into the stream. Also, log TU sum values for organic contaminants were elevated in both the hyporheic zone and stream. Thus, the overall chemical stress in the main discharge area is much higher than upstream, while it gradually decreases downstream. In conclusion, this work clearly shows that groundwater contaminant plumes can impact stream water quality significantly in discharge areas, and extend far downstream. A surprisingly high impact of heavy metals with diffuse and/or biogenic origin on stream quality was identified. This work highlights the importance of a holistic assessment of stream water quality to identify and quantify the main contaminant sources and resulting chemical stream stressors leading to potential ecological impacts.

Hydrogeology and Water Quality of the Pepacton Reservoir Watershed in Southeastern New York. Part 3. Responses of Stream Base-Flow Chemistry to Hydrogeologic Factors and Nonpoint-Sources of Contamination

USGS Publications Warehouse

Heisig, Paul M.; Phillips, Patrick J.

2004-01-01

The implications of this study are that seasonal and more frequent base-flow surveys of water chemistry from small stream basins can help refine the understanding of local hydrogeologic systems and define the effects of nonpointsource contamination on base-flow water quality. The concentration of most nonpoint sources in valley-bottom or lower-hillside areas helped indicate the relative contributions of water from hillside and valley-bottom areas at different times of year. The positive correlations between the intensity of nonpoint-source activities and nonpoint-source constituents in base flow underscores the link between land use (nonpoint sources), ground-water quality, and surface-water quality.

Occurrence of dichloroacetamide herbicide safeners and co-applied herbicides in midwestern U.S. streams

USGS Publications Warehouse

Woodward, Emily; Hladik, Michelle; Kolpin, Dana W.

2018-01-01

Dichloroacetamide safeners (e.g., AD-67, benoxacor, dichlormid, and furilazole) are co-applied with chloroacetanilide herbicides to protect crops from herbicide toxicity. While such safeners have been used since the early 1970s, there are minimal data about safener usage, occurrence in streams, or potential ecological effects. This study focused on one of these research gaps, occurrence in streams. Seven Midwestern U.S. streams (five in Iowa and two in Illinois), with extensive row-crop agriculture, were sampled at varying frequencies from spring 2016 through summer 2017. All four safeners were detected at least once; furilazole was the most frequently detected (31%), followed by benoxacor (29%), dichlormid (15%), and AD-67 (2%). The maximum concentrations ranged from 42 to 190 ng/L. Stream detections and concentrations of safeners appear to be driven by a combination of timing of application (spring following herbicide application) and precipitation events. Detected concentrations were below known toxicity levels for aquatic organisms.

Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

NASA Astrophysics Data System (ADS)

Ford, William I.; King, Kevin; Williams, Mark R.

2018-01-01

In landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can contribute to deleterious environmental conditions downstream. This study assessed upland and in-stream controls on baseflow nutrient concentrations in a low-gradient, tile-drained agroecosystem watershed. We conducted time-series analysis using Empirical mode decomposition of seven decade-long nutrient concentration time-series in the agricultural Upper Big Walnut Creek watershed (Ohio, USA). Four tributaries of varying drainage areas and three main-stem sites were monitored, and nutrient grab samples were collected weekly from 2006 to 2016 and analyzed for dissolved reactive phosphorus (DRP), nitrate-nitrogen (NO3-N), total nitrogen (TN), and total phosphorus (TP). Statistically significant seasonal fluctuations were compared with seasonality of baseflow, watershed characteristics (e.g., tile-drain density), and in-stream water quality parameters (pH, DO, temperature). Findings point to statistically significant seasonality of all parameters with peak P concentrations in summer and peak N in late winter-early spring. Results suggest that upland processes exert strong control on DRP concentrations in the winter and spring months, while coupled upland and in-stream conditions control watershed baseflow DRP concentrations during summer and early fall. Conversely, upland flow sources driving streamflow exert strong control on baseflow NO3-N, and in-stream attenuation through transient and permanent pathways impacts the magnitude of removal. Regarding TN and TP, we found that TN was governed by NO3-N, while TP was governed by DRP in summer and fluvial erosion of P-rich benthic sediments during higher baseflow conditions. Findings of the study highlight the importance of coupled in-stream and upland management for mitigating eutrophic conditions during environmentally sensitive timeframes.

Photosynthesis of amphibious and obligately submerged plants in CO2-rich lowland streams.

PubMed

Sand-Jensen, Kaj; Frost-Christensen, Henning

1998-11-01

Small unshaded streams in lowland regions receive drainage water with high concentrations of free␣CO 2 , and they support an abundant growth of amphibious and obligately submerged plants. Our first objective was to measure the CO 2 regime during summer in a wide range of small alkaline Danish streams subject to wide variation in temperature, O 2 and CO 2 during the day. The second objective was to determine the effect of these variations on daily changes in light-saturated photosynthesis in water of a homophyllous and a heterophyllous amphibious species that only used CO 2 , and an obligately submerged species capable of using both HCO - 3 and CO 2 . We found that the median CO 2 concentrations of the streams were 11 and 6 times above air saturation in the morning and the afternoon, respectively, but stream sites with dense plant growth had CO 2 concentrations approaching air saturation in the afternoon. In contrast, outlets from lakes had low CO 2 concentrations close to, or below, air saturation. The amphibious species showed a reduction of photosynthesis in water from morning to afternoon along with the decline in CO 2 concentrations, while increasing temperature and O 2 had little effect on photosynthesis. Photosynthesis of the obligately submerged species varied little with the change of CO 2 because of HCO 3 - - use, and variations were mostly due to changes in O 2 concentration. Independent measurements showed that changes in temperature, O 2 and CO 2 could account for the daily variability of photosynthesis of all three species in water. The results imply that CO 2 supersaturation in small lowland streams is important for the rich representation of amphibious species and their contribution to system photosynthesis.

Do Low-Mercury Terrestrial Resources Subsidize Low-Mercury Growth of Stream Fish? Differences between Species along a Productivity Gradient

PubMed Central

Ward, Darren M.; Nislow, Keith H.; Folt, Carol L.

2012-01-01

Low productivity in aquatic ecosystems is associated with reduced individual growth of fish and increased concentrations of methylmercury (MeHg) in fish and their prey. However, many stream-dwelling fish species can use terrestrially-derived food resources, potentially subsidizing growth at low-productivity sites, and, because terrestrial resources have lower MeHg concentrations than aquatic resources, preventing an increase in diet-borne MeHg accumulation. We used a large-scale field study to evaluate relationships among terrestrial subsidy use, growth, and MeHg concentrations in two stream-dwelling fish species across an in-stream productivity gradient. We sampled young-of-the-year brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo salar), potential competitors with similar foraging habits, from 20 study sites in streams in New Hampshire and Massachusetts that encompassed a wide range of aquatic prey biomass. Stable isotope analysis showed that brook trout used more terrestrial resources than Atlantic salmon. Over their first growing season, Atlantic salmon tended to grow larger than brook trout at sites with high aquatic prey biomass, but brook grew two-fold larger than Atlantic salmon at sites with low aquatic prey biomass. The MeHg concentrations of brook trout and Atlantic salmon were similar at sites with high aquatic prey biomass and the MeHg concentrations of both species increased at sites with low prey biomass and high MeHg in aquatic prey. However, brook trout had three-fold lower MeHg concentrations than Atlantic salmon at low-productivity, high-MeHg sites. These results suggest that differential use of terrestrial resource subsidies reversed the growth asymmetry between potential competitors across a productivity gradient and, for one species, moderated the effect of low in-stream productivity on MeHg accumulation. PMID:23166717

Water-quality characteristics of six small, semiarid watersheds in the Green River coal region of Colorado

USGS Publications Warehouse

Turk, John T.; Parker, Randolph S.

1982-01-01

Analysis of major and trace constituents in streams flowing through six semiarid watersheds indicates that the stream chemistry is characterized by saturation with respect to common carbonate minerals (calcium, magnesium, iron, manganese, and lead). The solubility of the carbonate minerals may be a major control on the absolute and relative concentrations of calcium, magnesium, bicarbonate, iron, manganese, and lead; however, other mechanisms probably control the concentrations of cadmium and zinc. Statistical analyses indicate that the mean concentrations of the major ions in the two climatic areas studied are significantly (P=0.05) different from one another, with larger mean concentrations in the more arid area. Trace-metal concentrations were similar from one area to another and indistinguishable from site to site (P=0.05) for lead, cadmium, and zinc. Linear regressions of major ion concentration to specific conductance are similar in both areas for sodium, bicarbonate, sulfate, and chloride. Results of the study may be useful in providing a first approximation of stream chemistry in other watersheds with the same geologic setting, determining watersheds with similar geochemical controls, and determining future changes in stream chemistry in the watersheds studied. (USGS)

Riparian zones attenuate nitrogen loss following bark beetle-induced lodgepole pine mortality

NASA Astrophysics Data System (ADS)

Biederman, Joel A.; Meixner, Thomas; Harpold, Adrian A.; Reed, David E.; Gutmann, Ethan D.; Gaun, Janelle A.; Brooks, Paul D.

2016-03-01

A North American bark beetle infestation has killed billions of trees, increasing soil nitrogen and raising concern for N loss impacts on downstream ecosystems and water resources. There is surprisingly little evidence of stream N response in large basins, which may result from surviving vegetation uptake, gaseous loss, or dilution by streamflow from unimpacted stands. Observations are lacking along hydrologic flow paths connecting soils with streams, challenging our ability to determine where and how attenuation occurs. Here we quantified biogeochemical concentrations and fluxes at a lodgepole pine-dominated site where bark beetle infestation killed 50-60% of trees. We used nested observations along hydrologic flow paths connecting hillslope soils to streams of up to third order. We found soil water NO3 concentrations increased 100-fold compared to prior research at this and nearby southeast Wyoming sites. Nitrogen was lost below the major rooting zone to hillslope groundwater, where dissolved organic nitrogen (DON) increased by 3-10 times (mean 1.65 mg L-1) and NO3-N increased more than 100-fold (3.68 mg L-1) compared to preinfestation concentrations. Most of this N was removed as hillslope groundwater drained through riparian soils, and NO3 remained low in streams. DON entering the stream decreased 50% within 5 km downstream, to concentrations typical of unimpacted subalpine streams (~0.3 mg L-1). Although beetle outbreak caused hillslope N losses similar to other disturbances, up to 5.5 kg ha-1y-1, riparian and in-stream removal limited headwater catchment export to <1 kg ha-1y-1. These observations suggest riparian removal was the dominant mechanism preventing hillslope N loss from impacting streams.

Phosphate dynamics in an acidic mountain stream: Interactions involving algal uptake, sorption by iron oxide, and photoreduction

USGS Publications Warehouse

Tate, Cathy M.; Broshears, Robert E.; McKnight, Diane M.

1995-01-01

Acid mine drainage streams in the Rocky Mountains typically have few algal species and abundant iron oxide deposits which can sorb phosphate. An instream injection of radiolabeled phosphate (32P0,) into St. Kevin Gulch, an acid mine drainage stream, was used to test the ability of a dominant algal species, Ulothrix sp., to rapidly assimilate phosphate. Approximately 90% of the injected phosphate was removed from the water column in the 175-m stream reach. When shaded stream reaches were exposed to full sunlight after the injection ended, photoreductive dissolution of iron oxide released sorbed 32P, which was then also removed downstream. The removal from the stream was modeled as a first-order process by using a reactive solute transport transient storage model. Concentrations of 32P mass-’ of algae were typically lo-fold greater than concentrations in hydrous iron oxides. During the injection, concentrations of 32P increased in the cellular P pool containing soluble, low-molecular-weight compounds and confirmed direct algal uptake of 32P0, from water. Mass balance calculations indicated that algal uptake and sorption on iron oxides were significant in removing phosphate. We conclude that in stream ecosystems, PO, sorbed by iron oxides can act as a dynamic nutrient reservoir regulated by photoreduction.

Long‐term trends in stream water and precipitation chemistry at five headwater basins in the northeastern United States

USGS Publications Warehouse

Clow, David W.; Mast, M. Alisa

1999-01-01

Stream water data from five headwater basins in the northeastern United States covering water years 1968–1996 and precipitation data from eight nearby precipitation monitoring sites covering water years 1984‐1996 were analyzed for temporal trends in chemistry using the nonparametric seasonal Kendall test. Concentrations of SO4declined at three of five streams during 1968–1996 (p < 0.1), and all of the streams exhibited downward trends in SO4 over the second half of the period (1984–1996). Concentrations of SO4 in precipitation declined at seven of eight sites from 1984 to 1996, and the magnitudes of the declines (−0.7 to −2.0 µeq L−1 yr−1) generally were similar to those of stream water SO4. These results indicate that changes in precipitation SO4 were of sufficient magnitude to account for changes in stream water SO4. Concentrations of Ca + Mg declined at three of five streams and five of eight precipitation sites from 1984 to 1996. Precipitation acidity decreased at five of eight sites during the same period, but alkalinity increased in only one stream. In most cases the decreases in stream water SO4 were similar in magnitude to declines in stream water Ca + Mg, which is consistent with the theory of leaching by mobile acid anions in soils. In precipitation the magnitudes of SO4 declines were similar to those of hydrogen, and declines in Ca +Mg were much smaller. This indicates that recent decreases in SO4 deposition are now being reflected in reduced precipitation acidity. The lack of widespread increases in stream water alkalinity, despite the prevalence of downward trends in stream water SO4, suggests that at most sites, increases in stream water pH and acid‐neutralizing capacity may be delayed until higher soil base‐saturation levels are achieved.

Occurrence of organic wastewater compounds in effluent-dominated streams in Northeastern Kansas

USGS Publications Warehouse

Lee, C.J.; Rasmussen, T.J.

2006-01-01

Fifty-nine stream-water samples and 14 municipal wastewater treatment facility (WWTF) discharge samples in Johnson County, northeastern Kansas, were analyzed for 55 compounds collectively described as organic wastewater compounds (OWCs). Stream-water samples were collected upstream, in, and downstream from WWTF discharges in urban and rural areas during base-flow conditions. The effect of secondary treatment processes on OWC occurrence was evaluated by collecting eight samples from WWTF discharges using activated sludge and six from WWTFs samples using trickling filter treatment processes. Samples collected directly from WWTF discharges contained the largest concentrations of most OWCs in this study. Samples from trickling filter discharges had significantly larger concentrations of many OWCs (p-value < 0.05) compared to samples collected from activated sludge discharges. OWC concentrations decreased significantly in samples from WWTF discharges compared to stream-water samples collected from sites greater than 2000??m downstream. Upstream from WWTF discharges, base-flow samples collected in streams draining predominantly urban watersheds had significantly larger concentrations of cumulative OWCs (p-value = 0.03), caffeine (p-value = 0.01), and tris(2-butoxyethyl) phosphate (p-value < 0.01) than those collected downstream from more rural watersheds.

Effect of climate on the trophic structure of temperate forested streams. a comparison of Mediterranean and Atlantic streams.

PubMed

Sabater, Sergi; Elosegi, Arturo; Acuña, Vicenç; Basaguren, Ana; Muñoz, Isabel; Pozo, Jesús

2008-02-15

Climate affects many aspects of stream ecosystems, although the presence of riparian forests can buffer differences between streams in different climatic settings. In an attempt to measure the importance of climate, we compared the seasonal patterns of hydrology, input and storage of allochthonous organic matter, and the trophic structure (abundance of algae and macroinvertebrates) in two temperate forested streams, one Mediterranean, the other Atlantic. Hydrology played a leading role in shaping the trophic structure of both streams. Frequency and timing of floods and droughts determined benthic detritus storage. Inputs and retention of allochthonous organic matter were higher in the Atlantic stream, whereas chlorophyll concentration was lower because of stronger light limitation. Instead, light availability and scour of particulate organic matter during late winter favoured higher chlorophyll concentration in the Mediterranean stream. As a result, in the Mediterranean stream grazers were more prevalent and consumers showed a higher dependence on autotrophic materials. On the other hand, the Atlantic stream depended on allochthonous materials throughout the whole study period. The overall trophic structure showed much stronger seasonality in the Mediterranean than in the Atlantic stream, this being the most distinctive difference between these two types of temperate streams. The different patterns observed in the two streams are an indication that climatic differences should be incorporated in proper measurements of ecosystem health.

Potential risk assessment in stream sediments, soils and waters after remediation in an abandoned W>Sn mine (NE Portugal).

PubMed

Antunes, I M H R; Gomes, M E P; Neiva, A M R; Carvalho, P C S; Santos, A C T

2016-11-01

The mining complex of Murçós belongs to the Terras de Cavaleiros Geopark, located in Trás-os-Montes region, northeast Portugal. A stockwork of NW-SE-trending W>Sn quartz veins intruded Silurian metamorphic rocks and a Variscan biotite granite. The mineralized veins contain mainly quartz, cassiterite, wolframite, scheelite, arsenopyrite, pyrite, sphalerite, chalcopyrite, galena, rare pyrrhotite, stannite, native bismuth and also later bismuthinite, matildite, joseite, roosveltite, anglesite, scorodite, zavaritskite and covellite. The exploitation produced 335t of a concentrate with 70% of W and 150t of another concentrate with 70% of Sn between 1948 and 1976. The exploitation took place mainly in four open pit mines as well as underground. Three lakes were left in the area. Remediation processes of confination and control of tailings and rejected materials and phytoremediation with macrophytes from three lakes were carried out between 2005 and 2007. Stream sediments, soils and water samples were collected in 2008 and 2009, after the remediation process. Most stream sediments showed deficiency or minimum enrichment for metals. The sequential enrichment factor in stream sediments W>Bi>As>U>Cd>Sn=Ag>Cu>Sb>Pb>Be>Zn is mainly associated with the W>Sn mineralizations. Stream sediments receiving drainage of a mine dump were found to be significantly to extremely enriched with W, while stream sediments and soils were found to be contaminated with As. Two soil samples collected around mine dumps and an open pit lake were also found to be contaminated with U. The waters from the Murçós W>Sn mine area were acidic to neutral. After the remediation, the surface waters were contaminated with F(-), Al, As, Mn and Ni and must not be used for human consumption, while open pit lake waters must also not be used for agriculture because of contamination with F(-), Al, Mn and Ni. In most waters, the As occurred as As (III), which is toxic and is easily mobilized in the drainage system. The remediation promoted a decrease in metals and As concentrations of soils and waters, however the applied processes were not enough to rehabilitate the area. Copyright © 2016 Elsevier Inc. All rights reserved.

State factor relationships of dissolved organic carbon and nitrogen losses from unpolluted temperate forest watersheds

USGS Publications Warehouse

Perakis, S.S.; Hedin, L.O.

2007-01-01

We sampled 100 unpolluted, old-growth forested watersheds, divided among 13 separate study areas over 5 years in temperate southern Chile and Argentina, to evaluate relationships among dominant soil-forming state factors and dissolved carbon and nitrogen concentrations in watershed streams. These watersheds provide a unique opportunity to examine broad-scale controls over carbon (C) and nitrogen (N) biogeochemistry in the absence of significant human disturbance from chronic N deposition and land use change. Variations in the ratio dissolved organic carbon (DOC) to nitrogen (DON) in watershed streams differed by underlying soil parent material, with average C:N = 29 for watersheds underlain by volcanic ash and basalt versus C:N = 73 for sedimentary and metamorphic parent materials, consistent with stronger adsorption of low C:N hydrophobic materials by amorphous clays commonly associated with volcanic ash and basalt weathering. Mean annual precipitation was related positively to variations in both DOC (range: 0.2-9.7 mg C/L) and DON (range: 0.008-0.135 mg N/L) across study areas, suggesting that variations in water volume and concentration may act synergistically to influence C and N losses across dry to wet gradients in these forest ecosystems. Dominance of vegetation by broadleaf versus coniferous trees had negligible effects on organic C and N concentrations in comparison to abiotic factors. We conclude that precipitation volume and soil parent material are important controls over chemical losses of dissolved organic C and N from unpolluted temperate forest watersheds. Our results raise the possibility that biotic imprints on watershed C and N losses may be less pronounced in naturally N-poor forests than in areas impacted by land use change and chronic N deposition. Copyright 2007 by the American Geophysical Union.

Source Areas of Water and Nitrate in a Peatland Catchment, Minnesota, USA

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.

2017-12-01

In nitrogen polluted forests, stream nitrate concentrations increase and some unprocessed atmospheric nitrate may be transported to streams during stormflow events. This understanding has emerged from forests with upland mineral soils. In contrast, catchments with northern peatlands may have both upland soils and lowlands with deep organic soils, each with unique effects on nitrate transport and processing. While annual budgets show nitrate yields to be relatively lower from peatland than upland-dominated catchments, little is known about particular runoff events when stream nitrate concentrations have been higher (despite long periods with little or no nitrate in outlet streams) or the reasons why. I used site knowledge and expansive/extensive monitoring at the Marcell Experimental Forest in Minnesota, along with a targeted 2-year study to determine landscape areas, water sources, and nitrate sources that affected stream nitrate variation in a peatland catchment. I combined streamflow, upland runoff, snow amount, and frost depth data from long-term monitoring with nitrate concentration, yield, and isotopic data to show that up to 65% of stream nitrate during snowmelt of 2009 and 2010 was unprocessed atmospheric nitrate. Up to 46% of subsurface runoff from upland soils during 2009 was unprocessed atmospheric nitrate, which shows the uplands to be a stream nitrate source during 2009, but not during 2010 when upland runoff concentrations were below the detection limit. Differences are attributable to variations in water and nitrate sources. Little snow (a nitrate source), less upland runoff relative to peatland runoff, and deeper soil frost in the peatland caused a relatively larger input of nitrate from the uplands to the stream during 2009 and the peatland to the stream during 2010. Despite the near-absence of stream nitrate during much of rest of the year, these findings show an important time when nitrate transport affected downstream aquatic ecosystems, reasons why nitrate was transported, and that atmospheric nitrate pollution had a direct effect on a stream in a peatland catchment. Furthermore, this work illustrates how long-term monitoring when coupled with shorter-duration studies allows contemporary questions to be addressed within legacy catchment studies.

Tritium monitor

DOEpatents

Chastagner, Philippe

1994-01-01

A system for continuously monitoring the concentration of tritium in an aqueous stream. The system pumps a sample of the stream to magnesium-filled combustion tube which reduces the sample to extract hydrogen gas. The hydrogen gas is then sent to an isotope separation device where it is separated into two groups of isotopes: a first group of isotopes containing concentrations of deuterium and tritium, and a second group of isotopes having substantially no deuterium and tritium. The first group of isotopes containing concentrations of deuterium and tritium is then passed through a tritium detector that produces an output proportional to the concentration of tritium detected. Preferably, the detection system also includes the necessary automation and data collection equipment and instrumentation for continuously monitoring an aqueous stream.

Tritium monitor

DOEpatents

Chastagner, P.

1994-06-14

A system is described for continuously monitoring the concentration of tritium in an aqueous stream. The system pumps a sample of the stream to magnesium-filled combustion tube which reduces the sample to extract hydrogen gas. The hydrogen gas is then sent to an isotope separation device where it is separated into two groups of isotopes: a first group of isotopes containing concentrations of deuterium and tritium, and a second group of isotopes having substantially no deuterium and tritium. The first group of isotopes containing concentrations of deuterium and tritium is then passed through a tritium detector that produces an output proportional to the concentration of tritium detected. Preferably, the detection system also includes the necessary automation and data collection equipment and instrumentation for continuously monitoring an aqueous stream. 1 fig.

Taking the pulse of snowmelt: in situ sensors reveal seasonal, event and diurnal patterns of nitrate and dissolved organic matter variability in an upland forest stream

USGS Publications Warehouse

Pellerin, Brian A.; Saraceno, John Franco; Shanley, James B.; Sebestyen, Stephen D.; Aiken, George R.; Wollheim, Wilfred M.; Bergamaschi, Brian A.

2011-01-01

Highly resolved time series data are useful to accurately identify the timing, rate, and magnitude of solute transport in streams during hydrologically dynamic periods such as snowmelt. We used in situ optical sensors for nitrate (NO3-) and chromophoric dissolved organic matter fluorescence (FDOM) to measure surface water concentrations at 30 min intervals over the snowmelt period (March 21–May 13, 2009) at a 40.5 hectare forested watershed at Sleepers River, Vermont. We also collected discrete samples for laboratory absorbance and fluorescence as well as δ18O–NO3- isotopes to help interpret the drivers of variable NO3- and FDOM concentrations measured in situ. In situ data revealed seasonal, event and diurnal patterns associated with hydrological and biogeochemical processes regulating stream NO3- and FDOM concentrations. An observed decrease in NO3- concentrations after peak snowmelt runoff and muted response to spring rainfall was consistent with the flushing of a limited supply of NO3- (mainly from nitrification) from source areas in surficial soils. Stream FDOM concentrations were coupled with flow throughout the study period, suggesting a strong hydrologic control on DOM concentrations in the stream. However, higher FDOM concentrations per unit streamflow after snowmelt likely reflected a greater hydraulic connectivity of the stream to leachable DOM sources in upland soils. We also observed diurnal NO3- variability of 1–2 μmol l-1 after snowpack ablation, presumably due to in-stream uptake prior to leafout. A comparison of NO3- and dissolved organic carbon yields (DOC, measured by FDOM proxy) calculated from weekly discrete samples and in situ data sub-sampled daily resulted in small to moderate differences over the entire study period (-4 to 1% for NO3- and -3 to -14% for DOC), but resulted in much larger differences for daily yields (-66 to +27% for NO3- and -88 to +47% for DOC, respectively). Despite challenges inherent in in situ sensor deployments in harsh seasonal conditions, these data provide important insights into processes controlling NO3- and FDOM in streams, and will be critical for evaluating the effects of climate change on snowmelt delivery to downstream ecosystems.