Science.gov

Sample records for determining seepage water

  1. Seepage water of northern Utah

    USGS Publications Warehouse

    Fortier, Samuel

    1897-01-01

    The term “seepage water” is used by the irrigators of the West to designate the water which reaches the lowest grounds or the stream channels, swelling the latter by imperceptible degrees and keeping up the flow long after the rains have ceased and the snow has melted. The word “seepage” is applied particularly to the water which begins to appear in spots below irrigation canals and cultivated fields, usually some months or even years after irrigation has been introduced, and which tends to convert the lowlands into marshes and gives rise to springs, which in turn may be employed in watering other fields.The importance of a thorough knowledge of the behavior of seepage water is obvious when consideration is given to the close relationship which exists between the available water supply and the material prosperity of the arid region where irrigation is practiced. This is particularly true of Utah, where every readily available source of supply has long since been utilized and where the rapidly increasing agricultural population necessitates the complete utilization of all fresh waters.

  2. A seepage meter designed for use in flowing water

    USGS Publications Warehouse

    Rosenberry, D.O.

    2008-01-01

    Seepage meters provide one of the most direct means to measure exchange of water across the sediment-water interface, but they generally have been unsuitable for use in fluvial settings. Although the seepage bag can be placed inside a rigid container to minimize velocity head concerns, the seepage cylinder installed in the sediment bed projects into and disrupts the flow field, altering both the local-scale fluid exchange as well as measurement of that exchange. A low-profile seepage meter designed for use in moving water was tested in a seepage meter flux tank where both current velocity and seepage velocity could be controlled. The conical seepage cylinder protrudes only slightly above the sediment bed and is connected via tubing to a seepage bag or flowmeter positioned inside a rigid shelter that is located nearby where current velocity is much slower. Laboratory and field tests indicate that the net effect of the small protrusion of the seepage cylinder into the surface water flow field is inconsequentially small for surface water currents up to 65 cm s-1. Current velocity affects the variability of seepage measurements; seepage standard deviation increased from ???2 to ???6 cm d-1 as current velocity increased from 9 to 65 cm s-1. Substantial bias can result if the shelter is not placed to minimize hydraulic gradient between the bag and the seepage cylinder.

  3. Seepage Reduction from Unlined Irrigation Canals: Water Quality and Seepage Reduction Effectiveness

    NASA Astrophysics Data System (ADS)

    Susfalk, R. B.; Epstein, B. J.; Schmidt, M.; Goreham, J.; Fitzgerald, B.; Young, M. H.; Martin, C.; Swihart, J.; Smith, D.

    2006-12-01

    Polyacrylamide is a class of long-chain synthetic polymers that is used extensively in food packaging, paper manufacturing, wastewater treatment, and as a soil amendment to reduce erosion. More recently, linear, anionic polyacrylamides (LA-PAM) have been used to reduce seepage from unlined irrigation canals in the western United States. A diverse set of experiments spanning multiple scales has been initiated to understand the efficacy of LA-PAM usage in canal environments. The physical application of granular LA-PAM to flowing canals is straightforward. However, granular PAM requires time to hydrate and react with sediment suspended in the water column, complicating the targeting of a specific canal reach for treatment. Factors that influence PAM's ability to reduce seepage will be discussed, and can include: water temperature, water velocity, and the cation balance and suspended sediment concentration in the canal water. The application method and mass of PAM that are applied are also important considerations. If the ability of PAM to form flocs with suspended sediment is overestimated, PAM will travel further downstream, potentially having an adverse impact on water quality and/or ecology. Negative impacts include livestock drinking out of the canal, the unintentional reduction of seepage water feeding adjacent wetlands or sensitive areas, and impacts on receiving waters. A combination of results from working canals and small scale, artificial Test Troughs will be used to address the impacts that different LA-PAM applications can have on water quality and seepage reduction effectiveness.

  4. 132. Credit JTL. Smaller feeder pipes collecting seepage and water ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    132. Credit JTL. Smaller feeder pipes collecting seepage and water from springs for the Eagle Canyon flume. - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  5. A system for calibrating seepage meters used to measure flow between ground water and surface water

    USGS Publications Warehouse

    Rosenberry, Donald O.; Menheer, Michael A.

    2006-01-01

    The in-line flowmeter used with this system is incapable of measuring seepage rates below about 7 centimeters per day. Smaller seepage rates can be measured manually. The seepage- control system also can be modified for measuring slower seepage rates with the use of two flowmeters and a slightly different water-routing system, or a fluid-metering pump can be used to control flow through the flux tank instead of an adjustable-height reservoir.

  6. Water quality effects of seepage from earthen dams

    USGS Publications Warehouse

    Yost, C.; Naney, J.W.

    1974-01-01

    Analyses of surface and seepage waters from selected floodwater retarding structures in west-central Oklahoma, U.S.A. show the salinity of seepage to be several times greater than that of the impounded waters. The increases in concentration of the several chemical components are not proportional. This phenomenon appears to be caused largely by simple solution, which is closely related to the chemical character of the geologic formation that provides the reservoir site and the earth fill of the dam. Concentration of certain chemical components in the seepage water progressively decreases as the structure ages. This is probably a function of depletion, which is related to the amounts and solubility of the parent materials subjected to solution. In contrast, the concentration of certain other components, such as iron and calcium, increases with time. The chemical activities within the accumulating mud on the bottom of the reservoir apparently cause these increases. ?? 1974.

  7. Variability and comparison of hyporheic water temperatures and seepage fluxes in a small Atlantic salmon stream.

    PubMed

    Alexander, Matthew D; Caissie, Daniel

    2003-01-01

    Ground water discharge is often a significant factor in the quality of fish spawning and rearing habitat and for highly biologically productive streams. In the present study, water temperatures (stream and hyporheic) and seepage fluxes were used to characterize shallow ground water discharge and recharge within thestreambed of Catamaran Brook, a small Atlantic salmon (Salmo salar) stream in central New Brunswick, Canada. Three study sites were instrumented using a total of 10 temperature sensors and 18 seepage meters. Highly variable mean seepage fluxes, ranging from 1.7 x 10(-4) to 2.5 cm3 m(-2) sec(-1), and mean hyporheic water temperatures, ranging from 10.5 degrees to 18.0 degrees C, at depths of 20 to 30 cm in the streambed were dependent on streambed location (left versus right stream bank and site location) and time during the summer sampling season. Temperature data were usefulfor determining if an area of the streambed was under discharge (positive flux), recharge (negative flux), or parallel flow (no flux) conditions and seepage meters were used to directly measure the quantity of water flux. Hyporheic water temperature measurements and specific conductance measurements of the seepage meter sample water, mean values ranging from 68.8 to 157.9 microS/cm, provided additional data for determining flux sources. Three stream banks were consistently under discharge conditions, while the other three stream banks showed reversal from discharge to recharge conditions over the sampling season. Results indicate that the majority of the water collected in the seepage meters was composed of surface water. The data obtained suggests that even though a positive seepage flux is often interpreted as ground water discharge, this discharging water may be of stream water origin that has recently entered the hyporheic zone.The measurement of seepage flux in conjunction with hyporheic water temperature or other indicators of water origin should be considered when attempting to

  8. Geohydrologic setting of and seepage from a water-supply canal, Indianapolis, Marion County, Indiana

    USGS Publications Warehouse

    Meyer, William R.

    1979-01-01

    The Indianapolis Water Company Canal is underlain by alluvial and outwash deposits. The water level in the canal on July 21, 1978, was above the water table along the entire reach of the canal upstream from the Fall Creek aqueduct, and, therefore, water was seeping downward from the canal into these deposits along this entire reach. Because of the highly variable lithology of the deposits underlying the canal, the seepage rate was probably also highly variable. Discharge measurements were made at selected points along the canal, and differences between successive measurements were calculated to determine the rate of water loss. The differences were smaller than the potential error in any of the measurements, however, and thus do not directly substantiate that water is being lost. The rate of water loss over the Fall Creek aqueduct by the skimming process could be as high as 43 cubic feet per second, assuming a 5% potential error for discharge measurements made at both ends of the aqueduct. Lower stages and water temperatures would decrease the rate of water loss. Observed ground-water levels were above the canal bottom at three locations along the canal. Lowering these levels below the bottom would increase seepage by approximately 9 cubic feet per second.

  9. Methane gas seepage - Disregard of significant water column filter processes?

    NASA Astrophysics Data System (ADS)

    Schneider von Deimling, Jens; Schmale, Oliver

    2016-04-01

    Marine methane seepage represents a potential contributor for greenhouse gas in the atmosphere and is discussed as a driver for climate change. The ultimate question is how much methane is released from the seafloor on a global scale and what fraction may reach the atmosphere? Dissolved fluxes from methane seepage sites on the seabed were found to be very efficiently reduced by benthic microbial oxidation, whereas transport of free gas bubbles from the seabed is considered to bypass the effective benthic methane filter. Numerical models are available today to predict the fate of such methane gas bubble release to the water column in regard to gas exchange with the ambient water column, respective bubble lifetime and rise height. However, the fate of rising gas bubbles and dissolved methane in the water column is not only governed by dissolution, but is also affected by lateral oceanographic currents and vertical bubble-induced upwelling, microbial oxidation, and physico-chemical processes that remain poorly understood so far. According to this gap of knowledge we present data from two study sites - the anthropogenic North Sea 22/4b Blowout and the natural Coal Oil point seeps - to shed light into two new processes gathered with hydro-acoustic multibeam water column imaging and microbial investigations. The newly discovered processes are hereafter termed Spiral Vortex and Bubble Transport Mechanism. Spiral Vortex describes the evolution of a complex vortical fluid motion of a bubble plume in the wake of an intense gas release site (Blowout, North Sea). It appears very likely that it dramatically changes the dissolution kinetics of the seep gas bubbles. Bubble Transport Mechanism prescribes the transport of sediment-hosted bacteria into the water column via rising gas bubbles. Both processes act as filter mechanisms in regard to vertical transport of seep related methane, but have not been considered before. Spiral Vortex and Bubble Transport Mechanism represent the

  10. Development of a benthic-flux chamber for measurement of ground-water seepage and water sampling for mercury analysis at the sediment-water interface

    USGS Publications Warehouse

    Menheer, M.A.

    2004-01-01

    A benthic-flux chamber was constructed to collect data to determine the relation between ground- and surface-water interaction and mercury concentrations in water at the sediment- water interface. The benthic-flux chamber was successfully used to measure the rate of ground water seeping to surface water or surface water seeping to ground water, and to collect water samples for mercury analysis from the sedimentwater interface in a lake setting. The benthic-flux chamber was designed to be deployed in relatively calm fresh water lakes, in areas of water less than 2 meters deep. The groundwater seepage rate data were comparable to data from an in-line flow meter in a calibration tank and with data from two 55-gallon drum seepage meters concurrently deployed in two different lakes. The benthic-flux chamber was used to collect possible water samples for analysis of total mercury and methylmercury concentrations.

  11. Integrating seepage heterogeneity with the use of ganged seepage meters

    USGS Publications Warehouse

    Rosenberry, D.O.

    2005-01-01

    The usefulness of standard half-barrel seepage meters for measurement of fluxes between groundwater, and surface water is limited by the small bed area that each measurement represents and the relatively large associated labor costs. Standard half-barrel cylinders were ganged together to allow one measurement of the summed seepage through all of the meters, reducing labor cost and increasing the representative area of measurement. Comparisons of ganged versus individual-meter measurements at two lakes, under both inseepage and outseepage conditions, indicate little loss of efficiency resulting from routing seepage water through the ganging system. Differences between summed and ganged seepage rates were not significant for all but the fastest rates of seepage. At flow rates greater than about 250 mL min-1, ganged values were as low as 80% of summed values. Ganged-meter head losses also were calculated to determine their significance relative to hydraulic-head gradients measured at the field sites. The calculated reduction in hydraulic gradient beneath the seepage meters was significant only for the largest measured seepage rates. A calibration tank was used to determine single-meter and ganged-meter efficiencies compared to known seepage rates. Single-cylinder seepage meters required an average correction factor of 1.05 to convert measured to actual values, whereas the ganged measurements made in the tank required a larger correction factor of 1.14. Although manual measurements were used in these tests, the concept of ganging seepage cylinders also would be useful when used in conjunction with automated flowmeters. ?? 2005, by the American Society of Limnology and Oceanography, Inc.

  12. Polyacrylamide and biopolymer effects on flocculation, aggregate stability, and water seepage in a silt loam

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researcher’s seek a more renewable and natural alternative for water soluble anionic polyacrylamide (PAM), a highly-effective, petroleum-derived polymer used in agriculture to control erosion and reduce water seepage from unlined irrigation structures. This study evaluated two anionic polymers: a ba...

  13. Numerical simulation experiments on water seepage patterns in heterogeneous, unsaturated rock fractures

    SciTech Connect

    Pruess, K.

    1996-05-01

    Water seepage has been numerically simulated in heterogeneous fractures, which were conceptualized as two-dimensional heterogeneous porous media. Flow was found to proceed in dendritic patterns along preferential paths, giving rise to such features as localized ponding and bypassing. Limited parameter variation studies have shown strong dependence of seepage patterns on fracture permeability and applied flow rate. The temporal evolution of seeps proceeds on a vast range of time scales. This casts doubt on the applicability of steady-state concepts for water migration in thick unsaturated zones of fractured rock where infiltration is episodic. An approximate invariance of seepage behavior was derived for simultaneous space-and-time scaling. Numerical simulation experiments have confirmed this invariance, as well as its limits of applicability.

  14. Purification of organic contaminants in seepage water of a landfill by UV/ozone technique

    NASA Astrophysics Data System (ADS)

    Vollmuth, S.; Wenzel, A.; Niessner, Reinhard

    1995-10-01

    Seepage water of landfills, where toxic waste is deposited, has high concentrations of chlorinated phenols (CP), polychlorinated biphenyls (PCB), and polycyclic aromatic hydrocarbons (PAH). The concentrations of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) are usually found at ppq-level. Typical purification methods based on physical techniques produce highly contaminated residues, which have to be removed by combustion or deposition in a landfill. An alternative way is to destruct these contaminants by biological and chemical treatment. The behavior of the trace contaminants during UV/ozone treatment is described. Results show no significant effect for PCB and PCDD/PCDF. The CP and PAH were mostly reduced by UV/ozone treatment to a degradation ratio greater than 90%. An influence of the pH value on the UV/ozone treatment of seepage water could not be detected. A further experiment showed the degradability of PCDD/PCDF in pure water solution. To reach better results for the degradation of organic trace contaminants the seepage water first can be treated with biological methods. Thus the high TOC-concentration of 3 g/l is reduced to 50 - 70%. A combination of biological and oxidative techniques diminishes the treatment costs and better exploitation of the oxidants is reached. Because of high light absorbance of the seepage water between 200 nm and 300 nm we developed a falling-film- photo-reactor to ensure, that every volume of the solution is exposed to UV-radiation.

  15. Purification of organic contaminants in seepage water of a landfill by UV/ozone-technique

    SciTech Connect

    Vollmuth, S.; Wenzel, A.; Niessner, R.

    1995-12-31

    Seepage water of landfills, where toxic waste is deposited, has a high concentrations of chlorinated phenols (CP), polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH). The concentrations of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) are usually found at ppq-level. Typical purification methods based on physical techniques produce highly contaminated residues, which have to be removed by combustion or depositing in a landfill. An alternative way is to destruct these contaminants by biological and chemical treatment. The behavior of the trace contaminants during UV/Ozone treatment is described. Results show no significant effect for PCB and PCDD/PCDF. The CP and PAH were mostly reduced by UV/ozone treatment to a degradation ratio greater than 90%. An influence of the pH value on the UV/ozone treatment of seepage water could not be detected. A further experiment showed the desirability of PCDD/PCDF in pure water solution. To reach better results for the degradation of organic trace contaminants the seepage water first can be treated with biological methods. Thus the high TOC-concentration of 3 g/l is reduced to 50--70%. A combination of biological and oxidative techniques diminishes the treatment costs and better exploitation of the oxidants is reached. Because of the high light absorbance of the seepage water between 200 nm and 300 nm the authors developed a falling-film-photo-reactor to ensure, that every volume part of the solution will be expose to UV-radiation.

  16. Simulation of Sub-Drains Performance Using Visual MODFLOW for Slope Water Seepage Problem

    NASA Astrophysics Data System (ADS)

    Baharuddin, M. F. T.; Tajudin, S. A. A.; Abidin, M. H. Z.; Yusoff, N. A.

    2016-07-01

    Numerical simulation technique was used for investigating water seepage problem at the Botanic Park Kuala Lumpur. A proposed sub-drains installation in problematic site location was simulated using Modular Three-Dimensional Finite Difference Groundwater Flow (MODFLOW) software. The results of simulation heads during transient condition showed that heads in between 43 m (water seepage occurred at level 2) until 45 m (water seepage occurred at level 4) which heads measurement are referred to mean sea level. However, elevations measurements for level 2 showed the values between 41 to 42 m from mean sea level and elevations for level 4 between 42 to 45 m from mean sea level. These results indicated an increase in heads for level 2 and level 4 between 1 to 2 m when compared to elevations slope at the level 2 and level 4. The head increases surpass the elevation level of the slope area that causing water seepage at level 2 and level 4. In order to overcome this problems, the heads level need to be decrease to 1 until 2 m by using two options of sub-drain dimension size. Sub-drain with the dimension of 0.0750 m (diameter), 0.10 m (length) and using 4.90 m spacing was the best method to use as it was able to decrease the heads to the required levels of 1 to 2 m.

  17. Processes of bedrock groundwater seepage and their effects on soil water fluxes in a foot slope area

    NASA Astrophysics Data System (ADS)

    Masaoka, Naoya; Kosugi, Ken'ichirou; Yamakawa, Yosuke; Tsutsumi, Daizo

    2016-04-01

    The impact of bedrock groundwater seepage on surface hydrological processes in a foot slope area is an important issue in hillslope hydrology. However, properties of water flux vectors around a seepage area are poorly understood because previous studies have lacked sufficient spatial resolution to capture detailed water movements. Here, we conducted hydrometric observations using unprecedented high-resolution and three-dimensional tensiometer nests in the mountainous foot slope area of the Hirudani experimental basin (Japan). Our findings are summarized as follows: (1) a considerable quantity of groundwater seeped from the bedrock surface in the study site. A groundwater exfiltration flux occurred constantly from a seepage area regardless of rainfall conditions. Saturated lateral flow over the bedrock surface occurred constantly in the region downslope of the seepage area. Groundwater was likely to mixed with soil water infiltration and flowed toward the lower end of the slope. (2) During the wet season, the seepage area expanded ∼3 m in the upslope direction along the bedrock valley in a single season. (3) The pressure head waveform observed in the seepage area showed gradual and significant increases after large rainfall events. However, the seepage pressure propagated within a relatively narrow area: a slope distance of ∼4 m from the seepage point in the downslope direction due to the damping of seepage pressure. (4) Within the whole study area, groundwater seeped from a narrow area located at the bottom of the valley line of the bedrock surface. The shape of the seepage area changed along the valley line in the wet season. Overall, we reveal spatial and temporal variations in bedrock groundwater seepage under the soil mantle and the effects on soil water fluxes. These findings should improve the accuracy of models for predicting surface hydrogeomorphological processes in mountainous hillslopes.

  18. Periodic seepage face formation and water pressure distribution along a vertical boundary of an aquifer

    NASA Astrophysics Data System (ADS)

    Jazayeri Shoushtari, Seyed Mohammad Hossein; Nielsen, Peter; Cartwright, Nick; Perrochet, Pierre

    2015-04-01

    Detailed measurements of the piezometric head from sand flume experiments of an idealised coastal aquifer forced by a simple harmonic boundary condition across a vertical boundary are presented. The measurements focus on the pore pressures very close to the interface (x = 0.01m) and throw light on the details of the boundary condition, particularly with respect to meniscus suction and seepage face formation during the falling tide. Between the low and the mean water level, the response is consistent with meniscus suction free models in terms of both the vertical mean head and oscillation amplitude profiles and is consistent with the observation that this area of the interface was generally within the seepage face. Above the mean water level, the influence of meniscus formation is significant with the mean pressure head being less than that predicted by capillary free theory and oscillation amplitudes decaying faster than predicted by suction free models. The reduced hydraulic conductivity in this area due to partial drainage of pores on the falling tide also causes a delay in the response to the rising tide. The combined influence of seepage face formation, meniscus suction and reduced hydraulic conductivity generate higher harmonics with amplitudes of up to 26% of the local main harmonic. To model the influence of seepage face formation and meniscus suction a numerical solution of the Richards' equation was developed and evaluated against the data. The model-data comparison shows a good agreement with the behaviour high above the water table sensitive to the choice of moisture retention parameters.

  19. Past methane seepage and linked deep-water anoxia are logged in methane-derived carbonates

    NASA Astrophysics Data System (ADS)

    Stadnitskaia, A.; Liebetrau, V.; Eisenhauer, A.; Sinninghe Damsté, J. S.

    2012-04-01

    The precipitation of carbonate in methane saturated environments is a common phenomenon that is caused by the increase of alkalinity due to the microbial process of anaerobic oxidation of methane (AOM) accomplished by a consortium of sulfate reducing bacteria and methanotrophic archaea (Boetius et al., 2000). Since the formation of such carbonates is irrespective to climate changes and to the depth of the carbonate compensation, they represent unique archives of the time and duration of methane seepage, adjacent sedimentary/water column environments and associated bionetwork. The Nile Deep Sea Fan basin is known for the widespread occurrence of seabed methane/fluid seepage linked to mud volcanoes and pock marks. Massive accumulations of methane-derived carbonate pavements and up to one meter buildups were often encountered in the vicinity or even within mud volcano structures. Here we analyzed at high resolution the differences in stable carbon and oxygen isotope compositions and lipid biomarker composition, accompanied with U/Th dating of the topmost part of a ~1 m-high carbonate edifice sited at the margin of the Amon mud volcano. The uppermost part of the edifice has been dated at ~7.8 - 9.1 kyr B.P. This is synchronous with the increase of fresh-water fluxes in the Eastern Mediterranean resulting in density stratification of the water column (~ 10.5 - 5.0 14C kyr B.P.), with the formation of S1 sapropel (~9.7 - 5.7 14C kyr B.P.; De Lange et al., 2008), and with the Holocene warm climatic optimum (Rohling and Hilgen, 1991). Significant changes of ^13CCaCO3 values, from -32 to -9‰ (VPDB), indicate swings in methane flux, which affected rates of AOM and the consequent production of 13C-depleted HCO3-. Lipid biomarkers revealed the presence of methanotrophic archaea of the ANME-2 group due to the dominance of sn-2-hydroxyarchaeol over archaeol and the low abundance of tetraether lipids (Blumenberg et al., 2004). Ecologically these archaea are associated with

  20. Influence of particle size on non-Darcy seepage of water and sediment in fractured rock.

    PubMed

    Liu, Yu; Li, Shuncai

    2016-01-01

    Surface water, groundwater and sand can flow into mine goaf through the fractured rock, which often leads to water inrush and quicksand movement. It is important to study the mechanical properties of water and sand in excavations sites under different conditions and the influencing factors of the water and sand seepage system. The viscosity of water-sand mixtures under different particle sizes, different concentration was tested based on the relationship between the shear strain rate and the surface viscosity. Using the self-designed seepage circuit, we tested permeability of water and sand in fractured rock. The results showed that (1) effective fluidity is in 10(-8)-10(-5) m(n+2) s(2-n)/kg, while the non-Darcy coefficient ranges from 10(5) to 10(8) m(-1) with the change of particle size of sand; (2) effective fluidity decreases as the particle size of sand increased; (3) the non-Darcy coefficient ranges from 10(5) to 10(8) m(-1) depending on particle size and showed contrary results. Moreover, the relationship between effective fluidity and the particle size of sand is fitted by the exponential function. The relationship between the non-Darcy coefficient and the particle size of sand is also fitted by the exponential function.

  1. Temporal variability of exchange between groundwater and surface water based on high-frequency direct measurements of seepage at the sediment-water interface

    USGS Publications Warehouse

    Rosenberry, Donald O.; Sheibley, Rich W.; Cox, Stephen E.; Simonds, Frederic W.; Naftz, David L.

    2013-01-01

    Seepage at the sediment-water interface in several lakes, a large river, and an estuary exhibits substantial temporal variability when measured with temporal resolution of 1 min or less. Already substantial seepage rates changed by 7% and 16% in response to relatively small rain events at two lakes in the northeastern USA, but did not change in response to two larger rain events at a lake in Minnesota. However, seepage at that same Minnesota lake changed by 10% each day in response to withdrawals from evapotranspiration. Seepage increased by more than an order of magnitude when a seiche occurred in the Great Salt Lake, Utah. Near the head of a fjord in Puget Sound, Washington, seepage in the intertidal zone varied greatly from −115 to +217 cm d−1 in response to advancing and retreating tides when the time-averaged seepage was upward at +43 cm d−1. At all locations, seepage variability increased by one to several orders of magnitude in response to wind and associated waves. Net seepage remained unchanged by wind unless wind also induced a lake seiche. These examples from sites distributed across a broad geographic region indicate that temporal variability in seepage in response to common hydrological events is much larger than previously realized. At most locations, seepage responded within minutes to changes in surface-water stage and within minutes to hours to groundwater recharge associated with rainfall. Likely implications of this dynamism include effects on water residence time, geochemical transformations, and ecological conditions at and near the sediment-water interface.

  2. Metal concentrations in soil and seepage water due to infiltration of roof runoff by long term numerical modelling.

    PubMed

    Zimmermann, J; Dierkes, C; Göbel, P; Klinger, C; Stubbe, H; Coldewey, W G

    2005-01-01

    The qualitative effects of stormwater infiltration on soil and seepage water are investigated with long term numerical modelling. The retention behaviour of different soils and materials used in infiltration devices is determined with batch and column tests. Results of the laboratory tests are adsorption isotherms which represent input data for numerical transport modelling. The long term simulations are performed with combinations of different solutions (types of roof runoff) and infiltration devices (swale and trench) under different hydrogeological conditions. The presented results contain the infiltration of low polluted roof runoff, runoff from a roof with zinc sheets and from a roof with copper sheets concerning the heavy metals zinc, copper and lead. The increase of concentrations in the infiltration body is high. For the infiltrated water, the results show a migration to groundwater only for the low adsorbing soil.

  3. High mobilization of arsenic, metals and rare earth elements in seepage waters driven by respiration of old allochthonous organic carbon.

    PubMed

    Weiske, Arndt; Schaller, Jörg; Hegewald, Tilo; Machill, Susanne; Werner, Ingo; Dudel, E Gert

    2013-12-01

    Metal and metalloid mobilization processes within seepage water are of major concern in a range of water reservoir systems. The mobilization process of arsenic and heavy metals within a dam and sediments of a drinking water reservoir was investigated. Principle component analysis (PCA) on time series data of seepage water showed a clear positive correlation of arsenic with iron and DOC (dissolved organic carbon), and a negative correlation with nitrate due to respiratory processes. A relationship of reductive metal and metalloid mobilization with respiration of old carbon was shown. The system is influenced by sediment layers as well as a recent DOC input from degraded ombrotrophic peatbogs in the catchment area. The isotopic composition ((12)C, (13)C and (14)C) of DOC is altered along the path from basin to seepage water, but no significant changes in structural parameters (LC-OCD-OND, FT-IR) could be seen. DIC (dissolved inorganic carbon) in seepage water partly originates from respiratory processes, and a higher relationship of it with sediment carbon than with the DOC inventory of infiltrating water was found. This study revealed the interaction of respiratory processes with metal and metalloid mobilization in sediment water flows. In contrast to the presumption that emerging DOC via respiratory processes mainly controls arsenic and metal mobilization it could be shown that the presence of aged carbon compounds is essential. The findings emphasize the importance of aged organic carbon for DOC, DIC, arsenic and metal turnover.

  4. Toxicity of Water Samples Collected in the Vicinity of F and H Seepage Basin 1990-1995

    SciTech Connect

    Specht, W.L.; Bowers, B.

    1996-09-01

    Water and contaminants from the F- and H-Area Seepage Basins outcrop as shallow groundwater seeps down gradient from the basins. In 1990, 1991, 1993, 1994, and 1995, toxicity tests were performed on water collected from a number of these seeps, as well as from several locations in Fourmile Branch and several uncontaminated reference locations.

  5. Geochemical characterisation of seepage and drainage water quality from two sulphide mine tailings impoundments: Acid mine drainage versus neutral mine drainage

    USGS Publications Warehouse

    Heikkinen, P.M.; Raisanen, M.L.; Johnson, R.H.

    2009-01-01

    Seepage water and drainage water geochemistry (pH, EC, O2, redox, alkalinity, dissolved cations and trace metals, major anions, total element concentrations) were studied at two active sulphide mine tailings impoundments in Finland (the Hitura Ni mine and Luikonlahti Cu mine/talc processing plant). The data were used to assess the factors influencing tailings seepage quality and to identify constraints for water treatment. Changes in seepage water quality after equilibration with atmospheric conditions were evaluated based on geochemical modelling. At Luikonlahti, annual and seasonal changes were also studied. Seepage quality was largely influenced by the tailings mineralogy, and the serpentine-rich, low sulphide Hitura tailings produced neutral mine drainage with high Ni. In contrast, drainage from the high sulphide, multi-metal tailings of Luikonlahti represented typical acid mine drainage with elevated contents of Zn, Ni, Cu, and Co. Other factors affecting the seepage quality included weathering of the tailings along the seepage flow path, process water input, local hydrological settings, and structural changes in the tailings impoundment. Geochemical modelling showed that pH increased and some heavy metals were adsorbed to Fe precipitates after net alkaline waters equilibrated with the atmosphere. In the net acidic waters, pH decreased and no adsorption occurred. A combination of aerobic and anaerobic treatments is proposed for Hitura seepages to decrease the sulphate and metal loading. For Luikonlahti, prolonged monitoring of the seepage quality is suggested instead of treatment, since the water quality is still adjusting to recent modifications to the tailings impoundment.

  6. Groundwater-Seepage Meter

    NASA Technical Reports Server (NTRS)

    Walthall, Harry G.; Reay, William G.

    1993-01-01

    Instrument measures seepage of groundwater into inland or coastal body of water. Positioned at depth as great as 40 meters, and measures flow at low rate and low pressure differential. Auxiliary pressure meter provides data for correlation of flow of groundwater with tides and sea states. Seepage meter operates independently for several weeks. Its sampling rate adjusted to suit hydrologic conditions; to measure more frequently when conditions changing rapidly. Used in water-quality management and for biological and geological research. Potential industrial uses include measurement of seepage of caustic and corrosive liquids.

  7. Abstraction of Drift Seepage

    SciTech Connect

    J.T. Birkholzer

    2004-11-01

    This model report documents the abstraction of drift seepage, conducted to provide seepage-relevant parameters and their probability distributions for use in Total System Performance Assessment for License Application (TSPA-LA). Drift seepage refers to the flow of liquid water into waste emplacement drifts. Water that seeps into drifts may contact waste packages and potentially mobilize radionuclides, and may result in advective transport of radionuclides through breached waste packages [''Risk Information to Support Prioritization of Performance Assessment Models'' (BSC 2003 [DIRS 168796], Section 3.3.2)]. The unsaturated rock layers overlying and hosting the repository form a natural barrier that reduces the amount of water entering emplacement drifts by natural subsurface processes. For example, drift seepage is limited by the capillary barrier forming at the drift crown, which decreases or even eliminates water flow from the unsaturated fractured rock into the drift. During the first few hundred years after waste emplacement, when above-boiling rock temperatures will develop as a result of heat generated by the decay of the radioactive waste, vaporization of percolation water is an additional factor limiting seepage. Estimating the effectiveness of these natural barrier capabilities and predicting the amount of seepage into drifts is an important aspect of assessing the performance of the repository. The TSPA-LA therefore includes a seepage component that calculates the amount of seepage into drifts [''Total System Performance Assessment (TSPA) Model/Analysis for the License Application'' (BSC 2004 [DIRS 168504], Section 6.3.3.1)]. The TSPA-LA calculation is performed with a probabilistic approach that accounts for the spatial and temporal variability and inherent uncertainty of seepage-relevant properties and processes. Results are used for subsequent TSPA-LA components that may handle, for example, waste package corrosion or radionuclide transport.

  8. Analysis of a mesoscale infiltration and water seepage test in unsaturated fractured rock: Spatial variabilities and discrete fracture patterns

    USGS Publications Warehouse

    Zhou, Q.; Salve, R.; Liu, H.-H.; Wang, J.S.Y.; Hudson, D.

    2006-01-01

    A mesoscale (21??m in flow distance) infiltration and seepage test was recently conducted in a deep, unsaturated fractured rock system at the crossover point of two underground tunnels. Water was released from a 3??m ?? 4??m infiltration plot on the floor of an alcove in the upper tunnel, and seepage was collected from the ceiling of a niche in the lower tunnel. Significant temporal and (particularly) spatial variabilities were observed in both measured infiltration and seepage rates. To analyze the test results, a three-dimensional unsaturated flow model was used. A column-based scheme was developed to capture heterogeneous hydraulic properties reflected by these spatial variabilities observed. Fracture permeability and van Genuchten ?? parameter [van Genuchten, M.T., 1980. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44, 892-898] were calibrated for each rock column in the upper and lower hydrogeologic units in the test bed. The calibrated fracture properties for the infiltration and seepage zone enabled a good match between simulated and measured (spatially varying) seepage rates. The numerical model was also able to capture the general trend of the highly transient seepage processes through a discrete fracture network. The calibrated properties and measured infiltration/seepage rates were further compared with mapped discrete fracture patterns at the top and bottom boundaries. The measured infiltration rates and calibrated fracture permeability of the upper unit were found to be partially controlled by the fracture patterns on the infiltration plot (as indicated by their positive correlations with fracture density). However, no correlation could be established between measured seepage rates and density of fractures mapped on the niche ceiling. This lack of correlation indicates the complexity of (preferential) unsaturated flow within the discrete fracture network. This also indicates that continuum

  9. Method to Determine the Global Thermogenic Methane Seepage Rate from the Helium Flux of the Continents

    NASA Astrophysics Data System (ADS)

    Hornafius, J. S.

    2012-12-01

    Bottom-up assessments of the contribution of natural hydrocarbon seepage from the earth to the global methane budget have quantified the emissions from small areas and attempted to extrapolate those measurements to a cumulative global emission rate, resulting in estimates of 18-48 Tg/yr (3-9% of the global methane budget). An alternative top-down method using helium is proposed to estimate the total emission rate of methane from natural hydrocarbon seepage worldwide from the equation: Qseeps = 4J 4 f g-1 f b c m c T c a where Qseeps is the quantity of methane emitted to the atmosphere annually (in Tg yr-1). 4J is the average flux of 4He atoms from the surface of the continents (4.18 x 1010atoms m-2 s-1), 4 f g-1 is the inverse of the global average fraction of natural hydrocarbon gases comprised of 4He in the subsurface, expressed as CH 4 (vol) / 4He (vol). The other variable is the fraction of the continents that are covered by sedimentary basins (f b ~0.4), which reduces the helium flux to the fraction that migrates through hydrocarbon reservoirs on the way to the surface. The constants convert 4He atoms m-2 s-1into 4He mass flux per m2 per year (c m = 2.11 x 10-16), 4He grams into CH 4 Teragrams (c T = 4.0 x 10-12) and c a is the area of the continents (1.53 x 1014 m2). This approach assumes the 4He flux from the continents is the same from basement shield areas as from sedimentary basins, and that the average 4He content of natural hydrocarbon seeps is the same as the 4He content of natural gases in subsurface reservoirs exploited for hydrocarbons worldwide. An internally consistent estimate of the 4He content of these gases can be determined from the increase in the 4He content of the atmosphere in the past 30 years, because this would be attributable to the worldwide hydrocarbon production during that period. A most likely increase of 4 x 1010 4He mol yr-1 and a maximum increase of 1.3 x 1011 4He mol y-1 has been measured at the experimental limit from the

  10. Relation between proposed developments of water resources and seepage from the All-American Canal, eastern Imperial Valley, California

    USGS Publications Warehouse

    Loeltz, Omar J.; Leake, S.A.

    1979-01-01

    A two-layer digital model designed for this study indicated that sealing of the Coachella branch of the All-American Canal would cause an eventual increase in seepage from the All-American Canal of about 15,000 acre-feet annually. Sealing of both the Coachella Canal and the segment of the All-American Canal between Pilot Knob and Drop 1 would result in a lessening of seepage rates from the All-American Canal of 57,000 acre-feet in 1985, but of only 39,000 acre-feet in 2030. Sealing both the Coachella and the All-American Canals would reduce the outflow to Mexicali Valley from 120,000 acre-feet in 1980 to less than 9 ,000 acre-feet in 2030. The model also indicated that if only the Coachella Canal was sealed, a little less than 40% of water pumped from proposed well fields near the All-American Canal ultimately would be derived from increased seepage from the All-American Canal; between 50 and 60% of the water pumped would be water that otherwise would flow to Mexicali Valley. (USGS)

  11. Lake Okeechobee seepage monitoring network

    USGS Publications Warehouse

    McKenzie, Donald J.

    1973-01-01

    This report summarizes the data collected at the five original monitoring sites along the south shore of Lake Okeechobee from January 29, 1970 to June 28, 1972. In order to use the hydrographs in this report to full advantage, they should be studied in conjunction with Meyer's graphs and text (1971). During steady-state conditions, water seeps from the lake through the filtercake and through the aquifers beneath the dike. At those sites where the filtercake is missing, or has about the same permeability as the aquifers, the seepage from the lake is about equivalent to the flow through the aquifers. Present data are insufficient to determine whether or not filtercake buildup has reduced seepage. No appreciable change in drainage occurred during the observed period.

  12. Evidence for Recent Liquid Water on Mars: Seepage Sites in 'Aerobraking Crater' Revisited

    NASA Technical Reports Server (NTRS)

    2000-01-01

    (A) [figure removed for brevity, see original site] (B) [figure removed for brevity, see original site] (C) (D) You will need 3D glasses to view this anaglyph

    The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65oS, 15oW (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill.

    Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed 'seepage' sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each 'v'. Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue '3D' glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start

  13. Local-scale variability of seepage and hydraulic conductivity in a shallow gravel-bed river

    USGS Publications Warehouse

    Rosenberry, D.O.; Pitlick, J.

    2009-01-01

    Seepage rate and direction measured with a seepage metre modified for use in flowing water were greatly variable along a 300-m reach of a shallow, gravel-bed river and depended primarily on the local-scale bed topography. The median value of seepage measured at 24 locations was 24 cm/day, but seepage measured at specific sites ranged from -340 to +237 cm/day. Seepage also varied substantially over periods of hours to days and occasionally reversed direction in response to evolution of the sediment bed. Vertical hydraulic conductivity was related to seepage direction and was larger during upward seepage than during downward seepage; with differences ranging from 4 to 40% in areas of active sediment transport to more than an order of magnitude in areas where current was too slow to mobilize bed sediment. Seepage was poorly related to hydraulic gradient measured over vertical distances of 0.3 m and appeared to be opposite the hydraulic gradient at 18% of the locations where both parameters were measured. Results demonstrate the scale dependence of these measurements in coarse-grained hyporheic settings and indicate that hydraulic gradients should be determined over a much shorter vertical increment if used to indicate exchange across the sediment-water interface. Published in 2009 by John Wiley & Sons, Ltd.

  14. Characterization of Preferential Ground-Water Seepage From a Chlorinated Hydrocarbon-Contaminated Aquifer to West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 2002-04

    USGS Publications Warehouse

    Majcher, Emily H.; Phelan, Daniel J.; Lorah, Michelle M.; McGinty, Angela L.

    2007-01-01

    , relatively low concentrations of chlorinated daughter compounds, and insignificant concentrations of methane in shallow pore water samples. These seeps were primarily along the creek edge or formed a dendritic-like pattern between the wetland and creek channel. In contrast, seep locations characterized as diffuse seeps contained relatively high concentrations of chlorinated daughter compounds (or a mixture of daughter and parent compounds) and detectable methane concentrations in shallow pore water samples. These seeps were primarily along the wetland boundary. Qualitative thermal infrared surveys coupled with quantitative verification of temperature differences, and screening for volatile organic compound and methane concentrations proved to be effective tools in determining the overall extent of preferential seepage. Hydrologic and physical properties of wetland sediments were characterized at two focused and one diffuse seep location. In the seeps with focused discharge, measured seepage was consistent over the tidal cycle, whereas more variability with tidal fluctuation was measured in the diffuse seep location. At all locations, areas were identified within the general seep boundaries where discharge was minimal. In all cases, the geometric mean of non-zero vertical flux measurements was greater than those previously reported in the non-seep wetland sediments using flow-net analysis. Flux was greater in the focused discharge areas than in the diffuse discharge area, and all fluxes were within the range reported in the literature for wetland discharge. Vertical hydraulic conductivity estimated from seepage flux and a mean vertical gradient at seeps with focused discharge resulted in a minimum hydraulic conductivity two orders of magnitude greater than those estimated in the non-seep sediment. In contrast, vertical conductivity estimates at a diffuse seep were similar to estimates along a nearby line of section through a non-seep area. Horizontal hydraulic cond

  15. Regeneration of mature Norway spruce stands: early effects of selective cutting and clear cutting on seepage water quality and soil fertility.

    PubMed

    Weis, W; Huber, C; Göttlein, A

    2001-11-10

    The cutting of trees influences element turnover in the forest ecosystem. The reduction of plant uptake, as well as an increased mineralization and nitrification due to higher soil temperature and soil moisture, can lead to considerable losses of nutrients from the main rooting zone. This may result in a reduced soil fertility and a decrease in drinking water quality due to high nitrate concentrations in the seepage water. In Bavaria (Germany) selective cutting is preferred to clear cutting when initiating the regeneration of Norway spruce stands with European beech. This paper summarizes the early effects of both forest management practices on soil fertility and seepage water quality for three different sites. Shown are the concentrations of nitrogen and base cations in the seepage water as well as the water and ion fluxes during the first year after tree cut. Nutrient inputs decreased on thinned plots and even more at clear-cuts. Nitrate concentrations in the seepage water are hardly affected by moderate thinning; however, on clear-cuts, the nitrate concentration increases significantly, and base cations are lost from the upper mineral soil. This effect is less obvious at sites where a dense ground vegetation, which is able to take up excess nitrogen, exists.

  16. Seasonal seepage investigation on an urbanized reach of the lower Boise River, southwestern Idaho, water year 2010

    USGS Publications Warehouse

    Williams, Marshall L.

    2011-01-01

    The U.S. Geological Survey in cooperation with the Idaho Department of Water Resources Treasure Valley Comprehensive Aquifer Management Planning effort investigated seasonal groundwater gains and losses on the Boise River, Idaho, starting in November 2009 through August 2010. The investigation was conducted using seepage runs in 11 subreaches over a 14-mile reach from downstream of the inactive streamgage, Boise River below Diversion Dam (U.S. Geological Survey station No. 13203510) to the active Boise River at Glenwood Bridge streamgage (U.S. Geological Survey station No. 13206000). The seepage runs measured mainstem discharge, and significant tributary contributions and diversions along the reach. In addition, an evaluation of the groundwater hydraulic gradient was simultaneously conducted through shallow groundwater mini-piezometers adjacent to the river during February (low stream discharge) and May (high stream discharge) measurement timeframes. November discharge estimates, representative of autumn, had gains and losses that varied by subreach with an overall net gain of 42 ± 8 cubic feet per second (ft3/s). This finding compares favorably to a previous U.S. Geological Survey seepage investigation in November 1996 that found a gaining reach with an estimated gain of 52 ft3/s. This finding also is supported by a U.S. Geological Survey investigation in the study reach in November 1971 that estimated a gain of 74 ft3/s, which largely came from groundwater. The February discharge estimates, representative of winter conditions, showed variability in the reach with a net gain of 52 ft3/s with an uncertainty estimate of ± 7 ft3/s, which is consistent with the low stream discharge findings from November 2009. This finding is further supported by the differential hydraulic head measured at transect sites that qualitatively indicated groundwater to surface-water movement with few exceptions. The May discharge estimates, representative of the spring-time conditions

  17. Drift-Scale THC Seepage Model

    SciTech Connect

    C.R. Bryan

    2005-02-17

    The purpose of this report (REV04) is to document the thermal-hydrologic-chemical (THC) seepage model, which simulates the composition of waters that could potentially seep into emplacement drifts, and the composition of the gas phase. The THC seepage model is processed and abstracted for use in the total system performance assessment (TSPA) for the license application (LA). This report has been developed in accordance with ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Post-Processing Analysis for THC Seepage) Report Integration'' (BSC 2005 [DIRS 172761]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this report. The plan for validation of the models documented in this report is given in Section 2.2.2, ''Model Validation for the DS THC Seepage Model,'' of the TWP. The TWP (Section 3.2.2) identifies Acceptance Criteria 1 to 4 for ''Quantity and Chemistry of Water Contacting Engineered Barriers and Waste Forms'' (NRC 2003 [DIRS 163274]) as being applicable to this report; however, in variance to the TWP, Acceptance Criterion 5 has also been determined to be applicable, and is addressed, along with the other Acceptance Criteria, in Section 4.2 of this report. Also, three FEPS not listed in the TWP (2.2.10.01.0A, 2.2.10.06.0A, and 2.2.11.02.0A) are partially addressed in this report, and have been added to the list of excluded FEPS in Table 6.1-2. This report has been developed in accordance with LP-SIII.10Q-BSC, ''Models''. This report documents the THC seepage model and a derivative used for validation, the Drift Scale Test (DST) THC submodel. The THC seepage model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral alteration on flow in rocks surrounding drifts. The DST THC submodel uses a drift

  18. Hydrogeologic setting, water budget, and preliminary analysis of ground-water exchange at Lake Starr, a seepage lake in Polk County, Florida

    USGS Publications Warehouse

    Swancar, Amy; Lee, T.M.; O'Hare, T. M.

    2000-01-01

    Lake Starr, a 134-acre seepage lake of multiple-sinkhole origin on the Lake Wales Ridge of central Florida, was the subject of a detailed water-budget study from August 1996 through July 1998. The study monitored the effects of hydrogeologic setting, climate, and ground-water pumping on the water budget and lake stage. The hydrogeologic setting of the Lake Starr basin differs markedly on the two sides of the lake. Ground water from the surficial aquifer system flows into the lake from the northwest side of the basin, and lake water leaks out to the surficial aquifer system on the southeast side of the basin. Lake Starr and the surrounding surficial aquifer system recharge the underlying Upper Floridan aquifer. The rate of recharge to the Upper Floridan aquifer is determined by the integrity of the intermediate confining unit and by the downward head gradient between the two aquifers. On the inflow side of the lake, the intermediate confining unit is more continuous, allowing ground water from the surficial aquifer system to flow laterally into the lake. Beneath the lake and on the southeast side of the basin, breaches in the intermediate confining unit enhance downward flow to the Upper Floridan aquifer, so that water flows both downward and laterally away from the lake through the ground-water flow system in these areas. An accurate water budget, including evaporation measured by the energy-budget method, was used to calculate net ground-water flow to the lake, and to do a preliminary analysis of the relation of net ground-water fluxes to other variables. Water budgets constructed over different timeframes provided insight on processes that affect ground-water interactions with Lake Starr. Weekly estimates of net ground-water flow provided evidence for the occurrence of transient inflows from the nearshore basin, as well as the short-term effects of head in the Upper Floridan aquifer on ground-water exchange with the lake. Monthly water budgets showed the effects

  19. Cycling of mercury across the sediment-water interface in seepage lakes: Chapter 13, Advances in Chemistry

    USGS Publications Warehouse

    Hurley, James P.; Krabbenhoft, David P.; Babiarz, C.L.; Andren, Anders

    1994-01-01

    The magnitude and direction of Hg fluxes across the sediment—water interface were estimated by groundwater, dry bulk sediment, sediment pore water, sediment trap, and water-column analyses in two northern Wisconsin seepage lakes. Little Rock Lake (Treatment Basin) received no groundwater discharge during the study period (1988—1990), and Follette Lake received continuous groundwater discharge. In Little Rock Lake, settling of particulate matter accounted for the major Hg delivery mechanism to the sediment—water interface. Upward diffusion of Hg from sediment pore waters below 2—4-cm sediment depth was apparently a minor source during summer stratification. Time-series comparisons suggested that the observed buildup of Hg in the hypolimnion of Little Rock Lake was attributable to dissolution and diffusion of Hg from recently fallen particulate matter close to the sediment—water interface. Groundwater inflow represented an important source of new Hg, and groundwater outflow accounted for significant removal of Hg from Pallette Lake. Equilibrium speciation calculations revealed that association of Hg with organic matter may control solubility in well-oxygenated waters, whereas in anoxic environments sulfur (polysulfide and bisulfide) complexation governs dissolved total Hg levels.

  20. Abstraction of Seepage into Drifts

    SciTech Connect

    M.L. Wilson; C.K. Ho

    2000-09-26

    A total-system performance assessment (TSPA) for a potential nuclear-waste repository requires an estimate of the amount of water that might contact waste. This paper describes the model used for part of that estimation in a recent TSPA for the Yucca Mountain site. The discussion is limited to estimation of how much water might enter emplacement drifts; additional considerations related to flow within the drifts, and how much water might actually contact waste, are not addressed here. The unsaturated zone at Yucca Mountain is being considered for the potential repository, and a drift opening in unsaturated rock tends to act as a capillary barrier and divert much of the percolating water around it. For TSPA, the important questions regarding seepage are how many waste packages might be subjected to water flow and how much flow those packages might see. Because of heterogeneity of the rock and uncertainty about the future (how the climate will evolve, etc.), it is not possible to predict seepage amounts or locations with certainty. Thus, seepage is treated as a stochastic quantity in TSPA simulations, with the magnitude and spatial distribution of seepage sampled from uncertainty distributions. The distillation of the essential components of process modeling into a form suitable for use in TSPA simulations is referred to as abstraction. In the following sections, seepage process models and abstractions will be summarized and then some illustrative results are presented.

  1. Interaction between hydrocarbon seepage, chemosynthetic communities and bottom water redox at cold seeps of the Makran accretionary prism: insights from habitat-specific pore water sampling and modeling

    NASA Astrophysics Data System (ADS)

    Fischer, D.; Sahling, H.; Nöthen, K.; Bohrmann, G.; Zabel, M.; Kasten, S.

    2011-09-01

    The interaction between fluid seepage, bottom water redox, and chemosynthetic communities was studied at cold seeps across one of the world's largest oxygen minimum zones (OMZ) located at the Makran convergent continental margin. Push cores were obtained from seeps within and at the lower boundary of the core-OMZ with a remotely operated vehicle. Extracted pore water was analyzed for sulfide and sulfate contents. Depending on oxygen availability, seeps were either colonized by microbial mats or by mats and macrofauna. The latter, including ampharetid polychaetes and vesicomyid clams, occurred in distinct benthic habitats which were arranged in a concentric fashion around gas orifices. At most sites colonized by microbial mats, hydrogen sulfide was exported into the bottom water. Where macrofauna was widely abundant, hydrogen sulfide was consumed within the sediment. Numerical modeling of pore water profiles was performed in order to assess rates of fluid advection and bioirrigation. While the magnitude of upward fluid flow decreased from 11 cm yr-1 to <1 cm yr-1 and the sulfate/methane transition zone (SMTZ) deepened with increasing distance from the central gas orifice, the fluxes of sulfate into the SMTZ did not significantly differ (6.6-9.3 mol m-2 yr-1). Depth-integrated rates of bioirrigation increased from 162 cm yr-1 in central habitats characterized by microbial mats and sparse macrofauna to 348 cm yr-1 in habitats of large and small vesicomyid clams. These results reveal that chemosynthetic macrofauna inhabiting the outer seep habitats at the lower boundary of the OMZ efficiently bioirrigate and thus transport sulfate into the upper 10 to 15 cm of the sediment. In this way bioirrigation compensates for the lower upward flux of methane in outer habitats and stimulates rates of anaerobic oxidation of methane (AOM) with sulfate high enough to provide sulfide for chemosynthesis. Through bioirrigation macrofauna engineer their geochemical environment and fuel

  2. Investigation of Seepage Meter Measurements in Steady Flow and Wave Conditions.

    PubMed

    Russoniello, Christopher J; Michael, Holly A

    2015-01-01

    Water exchange between surface water and groundwater can modulate or generate ecologically important fluxes of solutes across the sediment-water interface. Seepage meters can directly measure fluid flux, but mechanical resistance and surface water dynamics may lead to inaccurate measurements. Tank experiments were conducted to determine effects of mechanical resistance on measurement efficiency and occurrence of directional asymmetry that could lead to erroneous net flux measurements. Seepage meter efficiency was high (average of 93%) and consistent for inflow and outflow under steady flow conditions. Wave effects on seepage meter measurements were investigated in a wave flume. Seepage meter net flux measurements averaged 0.08 cm/h-greater than the expected net-zero flux, but significantly less than theoretical wave-driven unidirectional discharge or recharge. Calculations of unidirectional flux from pressure measurements (Darcy flux) and theory matched well for a ratio of wave length to water depth less than 5, but not when this ratio was greater. Both were higher than seepage meter measurements of unidirectional flux made with one-way valves. Discharge averaged 23% greater than recharge in both seepage meter measurements and Darcy calculations of unidirectional flux. Removal of the collection bag reduced this net discharge. The presence of a seepage meter reduced the amplitude of pressure signals at the bed and resulted in a nearly uniform pressure distribution beneath the seepage meter. These results show that seepage meters may provide accurate measurements of both discharge and recharge under steady flow conditions and illustrate the potential measurement errors associated with dynamic wave environments.

  3. Influence of Groundwater Seepage on Water Quality and Ecological Health of the Ria Formosa Lagoon, Southern Portugal (Invited)

    NASA Astrophysics Data System (ADS)

    Kontar, A. Y.; Newton, A.

    2009-12-01

    Groundwater seepage from coastal aquifers has recently been recognized as an overlooked major source of nutrients (N, P) and contaminants to the coastal environment (Biddanda et al., 2009; Fear, Paerl and Braddy, 2007; Kluge et al., 2007; Kroeger and Charette, 2008). Nutrient and contaminants concentrations in groundwater are often much higher than those in river water, compensating for the lower flux of groundwater relative to the lagoon surface water. The Ria Formosa is a coastal lagoon located in the south of Portugal (Algarve, Faro) and surrounded by an intensely farmed area. We hypothesize that water quality and ecological health of the Ria Formosa environments are influenced by past and on-going contamination of terrestrial groundwaters with nutrients from fertilizer, sewage and industry. According to Leote, Ibanhez and Rocha (2005) estimated submarine groundwater discharge (SGD) into the lagoon to be 3.6 m3 day-1 per linear meter of coastline with freshwater contributions (per volume) ranging from 10% to 50%. SGD as an important nutrient source to the Ria Formosa, estimating annual loads of 36.2 mol (0.507 kg) of Nitrogen, 1.1 mol (0.034 kg) of Phosphorus and 18.6 mol (0.522 kg) of Silicon per meter of coastline. Based on these results, it was suggested that SGD is a potential contributor to the observed nutrification status of the Ria Formosa lagoon. We are testing the following two hypotheses: (1) Anthropogenically impacted sites of the Ria Formosa having higher concentration of inorganic nutrients in groundwater will be characterized by higher density of Aquatic Invasive Species (AIS) distribution, and higher chlorophyll and phycocyanin concentration, oxygen demand, and sediment organic carbon than the pristine site; (2) Anthropogenically impacted sites of the Ria Formosa having higher concentration of contaminants in groundwater will be characterized by lower AIS dispersal and colonization, and lower chlorophyll and phycocyanin concentration, oxygen

  4. Simulation procedure of unconfined seepage with an inner seepage face in a heterogeneous field

    NASA Astrophysics Data System (ADS)

    Wu, MengXi; Yang, LianZhi; Yu, Ting

    2013-06-01

    An inner seepage face phenomenon is given and a numerical simulation procedure has been developed. It may appear at the interface of two materials when an unconfined seepage flows from a porous media to a coarser porous media with a higher permeability. Inaccuracy and divergent problems may arise both in a saturated-only and in a variably saturated analysis while an inner seepage face is not simulated with a special procedure. The position of the seepage face is determined during the nonlinear iteration process and the flux of the inner seepage face nodes is transferred to the downstream side nodes. Validity and efficiency of the procedure are illustrated by the simulation of two dimensional steady state seepage examples of heterogeneous zoned dams which is usually used to validate algorithms. An analysis of a three-dimensional earth core rockfill dam is also presented here. The procedure can also be applied to general transient seepage problems.

  5. Seepage Calibration Model and Seepage Testing Data

    SciTech Connect

    P. Dixon

    2004-02-17

    The purpose of this Model Report is to document the Seepage Calibration Model (SCM). The SCM is developed (1) to establish the conceptual basis for the Seepage Model for Performance Assessment (SMPA), and (2) to derive seepage-relevant, model-related parameters and their distributions for use in the SMPA and seepage abstraction in support of the Total System Performance Assessment for License Application (TSPA-LA). The SCM is intended to be used only within this Model Report for the estimation of seepage-relevant parameters through calibration of the model against seepage-rate data from liquid-release tests performed in several niches along the Exploratory Studies Facility (ESF) Main Drift and in the Cross Drift. The SCM does not predict seepage into waste emplacement drifts under thermal or ambient conditions. Seepage predictions for waste emplacement drifts under ambient conditions will be performed with the SMPA (see upcoming REV 02 of CRWMS M&O 2000 [153314]), which inherits the conceptual basis and model-related parameters from the SCM. Seepage during the thermal period is examined separately in the Thermal Hydrologic (TH) Seepage Model (see BSC 2003 [161530]). The scope of this work is (1) to evaluate seepage rates measured during liquid-release experiments performed in several niches in the Exploratory Studies Facility (ESF) and in the Cross Drift, which was excavated for enhanced characterization of the repository block (ECRB); (2) to evaluate air-permeability data measured in boreholes above the niches and the Cross Drift to obtain the permeability structure for the seepage model; (3) to use inverse modeling to calibrate the SCM and to estimate seepage-relevant, model-related parameters on the drift scale; (4) to estimate the epistemic uncertainty of the derived parameters, based on the goodness-of-fit to the observed data and the sensitivity of calculated seepage with respect to the parameters of interest; (5) to characterize the aleatory uncertainty of

  6. R Reactor seepage basins soil moisture and resistivity field investigation using cone penetrometer technology, Savannah River Site, Aiken, South Carolina

    SciTech Connect

    Harris, M.K.

    2000-02-17

    The focus of this report is the summer 1999 investigation of the shallow groundwater system using cone penetrometer technology characterization methods to determine if the water table is perched beneath the R Reactor Seepage Basins (RRSBs).

  7. Evaluation of 2D resistivity imaging technique for delineating subsurface seepage of hydrocarbon-contaminated water southeast of Karbala city, Iraq.

    PubMed

    Al-Menshed, Firas H; Thabit, Jassim M

    2017-01-10

    2D imaging technique was applied in (8) transects near a pit of contaminated water near contaminated well southeast of Karbala city, Iraq. Each transect was 30 m long with 1 m electrode spacing. Data acquisition was fulfilled by using Wenner electrode array. The resistivity of water-contaminated zone is found less than 3Ω.m and the top dry zone recorded relatively high resistivity (more than 170Ω.m). It is found that the greatest amount of seepage was found moving towards northeast direction coincided with groundwater movement direction, whereas there was no movement towards northwest and southeast directions and restricted on the closest areas to the pit location. The outcomes suggested that the 2D imaging technique is a successful and powerful tool in separating contaminated zone from clear one and in detecting underground seepage depth and moving direction.

  8. Active seepage and water infiltration in Lake Baikal sediments: new thermal data from TTR-Baikal 2014 (Class@Baikal)

    NASA Astrophysics Data System (ADS)

    Poort, Jeffrey; Khlystov, Oleg M.; Akhmanov, Grigorii G.; Khabuev, Andrei V.; Belousov, Oleg V.

    2015-04-01

    New thermal data from the sediments of Lake Baikal were collected in July 2014 during the first Training-Through-Research cruise on Lake Baikal (Class@Baikal) organized by MGU and LIN. TTR-Baikal is a comprehensive multidisciplinary program to train students on the field on pertinent scientific topics. The cruise program focused on seafloor sampling, acoustic investigations and heat flow measurements of gas seeps, flares, mud volcanoes, slumps and debris flows, canyons and channels in the coastal proximity. The thermal data were acquired using autonomous temperature sensors on a 3 meter long gravity corer that allowed analysis at the same spot of sediments, pore fluids, hydrates and microbiology. A total of eight thermal measurements were performed in five structures located on the lake floor of the Central Baikal Basin at 333-1530 meter water depths: 3 mud volcanoes (Novosibirsk, Unshuy and Krest), 1 seep site (Seep 13), and one fault outcrop in the Selenga transfer zone. All studied structures show signals of active seepage, water infiltration and/or hydrate dynamics. The strongest thermal gradient has been measured in Seep 13, suggesting a strong upflow of warm fluids similar to the Gorevoy Utes seep. At the three mud volcanoes, hydrate presence have been evidenced and both enhanced and reduced thermal gradients have been observed. This is similar to the hydrate-bearing K-2 mud volcano in Baikal (Poort et al., 2012). A strongly reduced thermal gradient was observed in the Krest mud volcano where the presence of oxidized channels at 30-40 cm under the sediment surface indicate an infiltration of cold lake water. The water infiltration process at hydrate bearing seep sites will be discussed and compared with other seep areas in the world.

  9. Influence of evaporation, ground water, and uncertainty in the hydrologic budget of Lake Lucerne, a seepage lake in Polk County, Florida

    USGS Publications Warehouse

    Lee, Terrie Mackin; Swancar, Amy

    1997-01-01

    A detailed hydrologic budget was constructed of a seepage lake of sinkhole origin in the karst terrain of central Florida. During the drought period studied, lake evaporation computed by the energy-budget and mass-transfer methods was the largest component in the budget, followed by rainfall. Ground-water inflow contributed about one-third of the total inflow. Lake leakage was about one-fourth of the evaporative losses and was increased substantially by pumping from the Upper Floridan aquifer.

  10. Effects on ground-water quality of seepage from a phosphatic clayey waste settling pond, north-central Florida

    USGS Publications Warehouse

    Hunn, J.D.; Seaber, P.R.

    1986-01-01

    Water samples were taken from test wells drilled near an inactive phosphatic clayey waste storage settling pond, from the settling pond and its perimeter ditch, and from an active settling pond near White Springs, Hamilton County, in north-central Florida. The purpose was to document the seepage of chemical constituents from the inactive settling pond and ditch into the adjacent surficial groundwater system, and to assess the potential for movement of these constituents into the deeper Floridan aquifer system which is the major source of public supply in the area. The study area is underlain by a 2 ,500-ft-thick sequence of Coastal Plain sediments of Early Cretaceous to Holocene age. The rocks of Tertiary and Quaternary age that underlie the test site area can be grouped into three major geohydrologic units. In descending order, these units are: surficial aquifer, Hawthorn confining unit, and Floridan aquifer system. Phosphate deposits occur in the upper part of the surficial aquifer. Water in the active settling pond is a calcium magnesium sulfate type with a dissolved solids concentration of 250 mg/L, containing greater amounts of phosphorus, iron, aluminum, barium, zinc, and chromium than the other surface waters. Water in the perimeter ditch is a calcium sulfate type with a dissolved solids concentration of 360 to 390 mg/L, containing greater amounts of calcium, sulfate, nitrogen, and fluoride than other surface waters. Water from the inactive settling pond is a calcium magnesium bicarbonate type with a dissolved solids concentration of 140 mg/L, containing more bicarbonate than the other surface waters. Large amounts of chemical constituents in the phosphate waste disposal slurry are apparently trapped in the sediments of the settling ponds. The quality of water in the upper part of the surficial aquifer from wells within 200 to 400 ft of the inactive settling pond shows no signs of chemical contamination from phosphate industry operations. The horizontal

  11. Modeling research on the response of geoelectric fields in a porous media seepage process

    NASA Astrophysics Data System (ADS)

    Zhou, Haitao; Gong, Xulong; Sun, Qiang; Yao, Yahui; Zhang, Rui

    2017-03-01

    Water seepage in rock and soil is a main inducing factor of accidents in many engineering fields such as tunnel engineering, mineral resource exploitation, and rock slopes. Water migration in rock and soil can lead to abnormal geoelectric fields due to the effects of diffusion, adsorption, filtration, and oxidation. This makes it possible to research the seepage law in porous media by measuring the response of geoelectric fields in this process. In this work, we carry out a physical simulation experiment to study the geoelectric field response occurring in the water-migration process. By analyzing the response of first electric potential, spontaneous potentials, and exciting current, we find that both the spontaneous potential and exciting current can reflect the change of seepage flow during the water-infiltration process. The exciting current and first electric potential is applicable to the seepage research on heterogeneous rock and soil, for they can accurately determine the position and velocity of the seepage. Real-time apparent resistivity not only indicates the infiltration area but also reflects the relative water content, i.e., the seepage reached saturation along with the reduction of the apparent resistivity.

  12. SEEPAGE/BACKFILL INTERACTIONS

    SciTech Connect

    P. Mariner

    2000-04-14

    As directed by written development plan (CRWMS M&O 1999a), a sub-model of seepage/backfill interactions is developed and presented in this document to support the Engineered Barrier System (EBS) Physical and Chemical Environment Model. The purpose of this analysis is to assist Performance Assessment Operations (PAO) and the Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift. In this analysis, a conceptual model is developed to provide PAO a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). The development plan calls for a sub-model that evaluates the effect on water chemistry of chemical reactions between water that enters the drift and backfill materials in the drift. The development plan specifically requests an evaluation of the following important chemical reaction processes: dissolution-precipitation, aqueous complexation, and oxidation-reduction. The development plan also requests the evaluation of the effects of varying seepage and drainage fluxes, varying temperature, and varying evaporation and condensation fluxes. Many of these effects are evaluated in a separate Analysis/Model Report (AMR), ''Precipitates Salts Analysis AMR'' (CRWMS M&O 2000), so the results of that AMR are referenced throughout this AMR.

  13. Nitrate-nitrogen concentrations in the perched ground water under seepage-irrigated potato cropping systems.

    PubMed

    Munoz-Arboleda, F; Mylavarapu, R; Hutchinson, C; Portier, K

    2008-01-01

    Excessive nitrogen rates for potato production in northeast Florida have been declared as a potential source of nitrate pollution in the St. Johns River watershed. This 3-yr study examined the effect of N rates (0, 168, and 280 kg ha(-1)) split between planting and 40 d after planting on the NO(3)-N concentration in the perched ground water under potato (Solanum tuberosum cv. Atlantic) in rotation with sorghum sudan grass hybrid (Sorghum vulgare x Sorghum vulgare var. sudanese, cv. SX17), cowpea (Vigna unguiculata cv. Iron Clay), and greenbean (Phaseolus vulgare cv. Espada). Soil solution from the root zone and water from the perched ground water under potato were sampled periodically using lysimeters and wells, respectively. Fertilization at planting increased the NO(3)-N concentration in the perched ground water, but no effect of the legumes in rotation with potatoes on nitrate leaching was detected. Fertilization of green bean increased NO(3)-N concentration in the perched ground water under potato planted in the following season. The NO(3)-N concentration in the soil solution within the potato root zone followed a similar pattern to that of the perched ground water but with higher initial values. The NO(3)-N concentration in the perched ground water was proportional to the rainfall magnitude after potato planting. A significant increase in NO(3)-N concentration in the perched ground water under cowpea planted in summer after potato was detected for the side-dressing of 168 kg ha(-1) N applied to potato 40 d after planting but not at the 56 kg ha(-1) N side-dress. Elevation in NO(3)-N concentration in the perched ground water under sorghum was not significant, supporting its use as an effective N catch crop.

  14. Electro-Osmotic Pulse Technology for Control of Water Seepage in Various Civil Works Structures

    DTIC Science & Technology

    2006-10-01

    higher viscosities have lower flowability . A higher pore solution viscosity would reduce the effectiveness of EOP. Electrical potential is the force...over the E6100 coat in order to fill in any gaps that may have formed during curing. No water could transfer along any gaps in the PVC-concrete...enough to prevent overheating of the concrete and water (electrolyte) due to ohmic losses, V = I2R. The cathode side of the tank was filled with 6

  15. Seepage Calibration Model and Seepage Testing Data

    SciTech Connect

    S. Finsterle

    2004-09-02

    The purpose of this Model Report is to document the Seepage Calibration Model (SCM). The SCM was developed (1) to establish the conceptual basis for the Seepage Model for Performance Assessment (SMPA), and (2) to derive seepage-relevant, model-related parameters and their distributions for use in the SMPA and seepage abstraction in support of the Total System Performance Assessment for License Application (TSPA-LA). This Model Report has been revised in response to a comprehensive, regulatory-focused evaluation performed by the Regulatory Integration Team [''Technical Work Plan for: Regulatory Integration Evaluation of Analysis and Model Reports Supporting the TSPA-LA'' (BSC 2004 [DIRS 169653])]. The SCM is intended to be used only within this Model Report for the estimation of seepage-relevant parameters through calibration of the model against seepage-rate data from liquid-release tests performed in several niches along the Exploratory Studies Facility (ESF) Main Drift and in the Cross-Drift. The SCM does not predict seepage into waste emplacement drifts under thermal or ambient conditions. Seepage predictions for waste emplacement drifts under ambient conditions will be performed with the SMPA [''Seepage Model for PA Including Drift Collapse'' (BSC 2004 [DIRS 167652])], which inherits the conceptual basis and model-related parameters from the SCM. Seepage during the thermal period is examined separately in the Thermal Hydrologic (TH) Seepage Model [see ''Drift-Scale Coupled Processes (DST and TH Seepage) Models'' (BSC 2004 [DIRS 170338])]. The scope of this work is (1) to evaluate seepage rates measured during liquid-release experiments performed in several niches in the Exploratory Studies Facility (ESF) and in the Cross-Drift, which was excavated for enhanced characterization of the repository block (ECRB); (2) to evaluate air-permeability data measured in boreholes above the niches and the Cross-Drift to obtain the permeability structure for the seepage model

  16. H-Area Seepage Basins

    SciTech Connect

    Stejskal, G.

    1990-12-01

    During the third quarter of 1990 the wells which make up the H-Area Seepage Basins (H-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, nonvolatile beta, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, nonvolatile beta, trichloroethylene (TCE), tetrachloroethylene, lead, cadmium, arsenic, and total radium.

  17. Impact of aquifer desaturation on steady-state river seepage

    NASA Astrophysics Data System (ADS)

    Morel-Seytoux, Hubert J.; Miracapillo, Cinzia; Mehl, Steffen

    2016-02-01

    Flow exchange between surface and ground water is of great importance be it for beneficial allocation and use of the water resources or for the proper exercise of water rights. That exchange can take place under a saturated or unsaturated flow regime. Which regimes occur depend on conditions in the vicinity of the interactive area. Withdrawals partially sustained by seepage may not bring about desaturation but greater amounts eventually will. The problem considered in this paper deals only with the steady-state case. It is meant as a first step toward a simple, yet accurate and physically based treatment of the transient situation. The primary purpose of the article is to provide simple criteria for determination of the initiation of desaturation in an aquifer originally in saturated hydraulic connection with a river or a recharge area. The extent of the unsaturated zone in the aquifer will increase with increasing withdrawals while at the same time the seepage rate from the river increases. However the seepage increase will stop once infiltration takes place strictly by gravity in the aquifer and is no longer opposed by the capillary rise from the water table below the riverbed. Following desaturation simple criteria are derived and simple analytical formulae provided to estimate the river seepage based on the position of the water table mound below the clogging layer and at some distance away from the river bank. They fully account for the unsaturated flow phenomena, including the existence of a drainage entry pressure. Two secondary objectives were to verify that (1) the assumption of uniform vertical flow through a clogging layer and that (2) the approximation of the water table mound below the seepage area as a flat surface were both reasonably legitimate. This approach will be especially advantageous for the implementation of the methodology in large-scale applications of integrated hydrologic models used for management.

  18. Effects of seepage from fly-ash settling ponds and construction dewatering on ground-water levels in the Cowles unit, Indiana Dunes National Lakeshore, Indiana

    USGS Publications Warehouse

    Meyer, William R.; Tucci, Patrick

    1979-01-01

    Part of the Indiana Dunes National Lakeshore shares a common boundary with the Northern Indiana Public Service Company (NIPSCO). This area is underlain by unconsolidated deposits approximately 180 feet thick. NIPSCO accumulates fly ash from the burning of coal in electric-power generating units in settling ponds. Seepage from the ponds has raised ground-water levels above natural levels approximately 15 feet under the ponds and more than 10 feet within the Lakeshore. NIPSCO is presently (1977) constructing a nuclear powerplant, and construction activities include pumping ground water to dewater the construction site. The company has installed a slurry wall around the site to prevent lowering of ground-water levels within the Lakeshore. Plans call for continuous pumping through at least December 1979. A multilayered digital flow model was constructed to simulate the ground-water system. The model was used to demonstrate the effects of seepage from the fly-ash ponds on ground-water levels. Also, the model indicated a decline of 3 feet or less in the upper sand unit and 5 feet or less in the lower sand unit within the Lakeshore.

  19. Water chemistry, seepage investigation, streamflow, reservoir storage, and annual availability of water for the San Juan-Chama Project, northern New Mexico, 1942-2010

    USGS Publications Warehouse

    McKean, Sarah E.; Anderholm, Scott K.

    2014-01-01

    The Albuquerque Bernalillo County Water Utility Authority supplements the municipal water supply for the Albuquerque metropolitan area, in central New Mexico, with surface water diverted from the Rio Grande. The U.S. Geological Survey, in cooperation with the Albuquerque Bernalillo County Water Utility Authority, undertook this study in which water-chemistry data and historical streamflow were compiled and new water-chemistry data were collected to characterize the water chemistry and streamflow of the San Juan-Chama Project (SJCP). Characterization of streamflow included analysis of the variability of annual streamflow and comparison of the theoretical amount of water that could have been diverted into the SJCP to the actual amount of water that was diverted for the SJCP. Additionally, a seepage investigation was conducted along the channel between Azotea Tunnel Outlet and the streamflow-gaging station at Willow Creek above Heron Reservoir to estimate the magnitude of the gain or loss in streamflow resulting from groundwater interaction over the approximately 10-mile reach. Generally, surface-water chemistry varied with streamflow throughout the year. Streamflow ranged from high flow to low flow on the basis of the quantity of water diverted from the Rio Blanco, Little Navajo River, and Navajo River for the SJCP. Vertical profiles of the water temperature over the depth of the water column at Heron Reservoir indicated that the reservoir is seasonally stratified. The results from the seepage investigations indicated a small amount of loss of streamflow along the channel. Annual variability in streamflow for the SJCP was an indication of the variation in the climate parameters that interact to contribute to streamflow in the Rio Blanco, Little Navajo River, Navajo River, and Willow Creek watersheds. For most years, streamflow at Azotea Tunnel Outlet started in March and continued for approximately 3 months until the middle of July. The majority of annual streamflow

  20. Use of an Electromagnetic Seepage Meter to Investigate Temporal Variability in Lake Seepage

    USGS Publications Warehouse

    Rosenberry, D.O.; Morin, R.H.

    2004-01-01

    A commercially available electromagnetic flowmeter is attached to a seepage cylinder to create an electromagnetic seepage meter (ESM) for automating measurement of fluxes across the sediment/water interface between ground water and surface water. The ESM is evaluated through its application at two lakes in New England, one where water seeps into the lake and one where water seeps out of the lake. The electromagnetic flowmeter replaces the seepage-meter bag and provides a continuous series of measurements from which temporal seepage processes can be investigated. It provides flow measurements over a range of three orders of magnitude, and contains no protruding components or moving parts. The ESM was used to evaluate duration of seepage disturbance following meter installation and indicated natural seepage rates resumed approximately one hour following meter insertion in a sandy lakebed. Lakebed seepage also varied considerably in response to lakebed disturbances, near-shore waves, and rain-falls, indicating hydrologic processes are occurring in shallow lakebed settings at time scales that have largely gone unobserved.

  1. Use of hydrologic budgets and hydrochemistry to determine ground-water and surface-water interactions for Rapid Creek, Western South Dakota

    USGS Publications Warehouse

    Anderson, Mark T.

    1995-01-01

    The study of ground-water and surface-water interactions often employs streamflow-gaging records and hydrologic budgets to determine ground-water seepage. Because ground-water seepage usually is computed as a residual in the hydrologic budget approach, all uncertainty of measurement and estimation of budget components is associated with the ground-water seepage. This uncertainty can exceed the estimate, especially when streamflow and its associated error of measurement, is large relative to other budget components. In a study of Rapid Creek in western South Dakota, the hydrologic budget approach with hydrochemistry was combined to determine ground-water seepage. The City of Rapid City obtains most of its municipal water from three infiltration galleries (Jackson Springs, Meadowbrook, and Girl Scout) constructed in the near-stream alluvium along Rapid Creek. The reach of Rapid Creek between Pactola Reservoir and Rapid City and, in particular the two subreaches containing the galleries, were studied intensively to identify the sources of water to each gallery. Jackson Springs Gallery was found to pump predominantly ground water with a minor component of surface water. Meadowbrook and Girl Scout Galleries induce infiltration of surface water from Rapid Creek but also have a significant component of ground water.

  2. Use of geophysical methods to map subsurface features at levee seepage locations

    NASA Astrophysics Data System (ADS)

    Brackett, Thomas C.

    The Great Flood of 2011 caused moderate to severe seepage and piping along the Mississippi River levees in Northwest Mississippi. The aim of this thesis was to implement geophysical techniques at two seepage locations in order to give a better understanding of the causes of underseepage and information on how to mitigate the problem. Sites near Rena Lara in Coahoma County and near Francis in Bolivar County were chosen to conduct this survey. Electrical Resistivity Tomography (ERT) and Electromagnetic Induction (EM) surveys were conducted on and adjacent to levees to identify seepage pathways and any dominant geological features at the sites. Results from geophysical surveys revealed that Francis and Rena Laura each had a prominent geomorphologic feature that was attributing to underseepage. Seepage at Francis was the result of a sand filled channel capped by a clay overburden. Permeable materials at the base of the channel served as a conduit for transporting river water beneath the levee. The seepage surfaced as sand boils where the overlying clay overburden was thin or non-existent. Investigations at the Rena Lara site revealed a large, clay-filled swale extending beneath the levee. The clay within the swale has relatively low horizontal permeability, and concentrated the seepage flow towards more permeable zones on the flanks of the swale. This resulted in the formation of sand boils at the base of the levee. Both geomorphic features at Francis and Rena Lara were identified as surface drainages using remote sensing data. With the assistance of borehole and elevation data, geophysics was successfully used to characterize the features at each site. Properties such as permeability and clay content were derived from responses in electrical conductivity and used to build seepage models at each site. These models will hopefully be considered when determining seepage conditions and mitigation techniques at other sites along the levee.

  3. Synoptic estimates of diffuse groundwater seepage to a spring-fed karst river at high spatial resolution using an automated radon measurement technique

    NASA Astrophysics Data System (ADS)

    Khadka, Mitra B.; Martin, Jonathan B.; Kurz, Marie J.

    2017-01-01

    Groundwater (GW) seepage can provide a major source of water, solutes, and contaminants to rivers, but identifying magnitudes, directions and locations of seepage is complicated by its diffuse and heterogeneous distributions. However, such information is necessary to develop programs and policies for protecting ecosystems and managing water resources. Here, we assess GW seepage to the Ichetucknee River, a spring-fed, low gradient, gaining stream in north-central Florida, through automated longitudinal surveys of radon (222Rn) activities at three different flow conditions. A 222Rn mass balance model, which integrates groundwater and spring water end member 222Rn activities and longitudinal 222Rn distributions in river water, shows that diffuse groundwater seepage represents about 16% of the total river baseflow, consistent with previous results obtained from ion (Ca2+, Cl-, SRP and Fe) mass balances and dye tracer methods. During high river stage, the contribution from seepage increases to 18-23% of the river flow. The spatial distribution of GW seepage is more variable in the upper 2.2-km reach of the river than the lower 2.8-km reach, regardless of river flow conditions. The upper reach has a narrower flood plain than the lower reach, which limits evapotranspiration and increases hydraulic gradients toward the river following storm events. Seepage in the lower reach is also limited by hydrologic damming by the receiving river, which inundates the floodplain during high flow conditions, and reduces the hydraulic head gradient. These results demonstrate the variable nature of seepage to a gaining river in both time and space and indicate that multiple synoptic analyses of GW seepage are required to assess seepage rates, determine time-averaged solute fluxes, and develop optimal management policies for riverine ecosystems.

  4. Geophysical and Hydrologic Studies of Lake Seepage Variability.

    PubMed

    Toran, Laura; Nyquist, Jonathan; Rosenberry, Donald; Gagliano, Michael; Mitchell, Natasha; Mikochik, James

    2015-01-01

    Variations in lake seepage were studied along a 130 m shoreline of Mirror Lake NH. Seepage was downward from the lake to groundwater; rates measured from 28 seepage meters varied from 0 to -282 cm/d. Causes of this variation were investigated using electrical resistivity surveys and lakebed sediment characterization. Two-dimensional (2D) resistivity surveys showed a transition in lakebed sediments from outwash to till that correlated with high- and low-seepage zones, respectively. However, the 2D survey was not able to predict smaller scale variations within these facies. In the outwash, fast seepage was associated with permeability variations in a thin (2 cm) layer of sediments at the top of the lakebed. In the till, where seepage was slower than that in the outwash, a three-dimensional resistivity survey mapped a point of high seepage associated with heterogeneity (lower resistivity and likely higher permeability). Points of focused flow across the sediment-water interface are difficult to detect and can transmit a large percentage of total exchange. Using a series of electrical resistivity geophysical methods in combination with hydrologic data to locate heterogeneities that affect seepage rates can help guide seepage meter placement. Improving our understanding of the causes and types of heterogeneity in lake seepage will provide better data for lake budgets and prediction of mass transfer of solutes or contaminants between lakes and groundwater.

  5. Seepage through a hazardous-waste trench cover

    USGS Publications Warehouse

    Healy, R.W.

    1989-01-01

    Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216 mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest rates occurred along the edge of the cover, where seepage was highly episodic, with 84% of the total there being traced to wetting fronts from 28 individual storms. Limitations of the zero-flux-plane method were severe enough for the method to be judged inappropriate for use in this study.Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest

  6. Field Analogues of Shallow-water Hydrocarbon Seepages in the Pleistocene Argille Azzurre Formation: the Chimneys Field of Enza River, Northern Apennines, Italy

    NASA Astrophysics Data System (ADS)

    Oppo, D.; Capozzi, R.; Dinelli, E.; Negri, A.; Montagna, P.; Picotti, V.; Scarponi, D.; Taviani, M.

    2012-12-01

    The geologically young Northern Apennines contain various natural seeps documenting a variability of reservoirs and fluids in terms of origin, age and evolution. Hydrocarbon and saline water seepages are controlled by the structures of the chain and the foredeep. In the geological record, the witness of these natural seepages are represented by authigenic carbonates. Their isotopic content allows to understand the carbon source and the processes of carbonate precipitation. The better known regional examples of Methane Derived Authigenic Carbonates (MDAC) and chemoherm build-ups, clustered in the Upper Miocene and Lower-Upper Pliocene successions, are formed in deep water (> 300 m) sediments. Occurrences in shallow water (shelf) settings have never been reported. Our case study describes the palisade chimneys field, recently exposed along the Enza riverbanks in the Northern Apennines in the Argille Azzurre Formation (blue mudstones) of Pleistocene age. The paleontological content (mainly bivalves) documents that this unit was deposited in an open marine muddy shelfal setting, in a bathymetric range of about 50-70 m, with local anoxic condition, documented by benthic foraminifer assemblages. The succession is biostratigraphically dated at the Early Pleistocene (Calabrian, nannoplancton zone MNN19e). A number of subvertical, metric-high columnar chimneys, ranging in diameter from 10 to 35 cm, in association with discontinuous planar carbonate concretions, intervening along the bedding planes, outcrop within the mudstones. Such concretions are clearly formed by the moderate cementation of the hosting pelitic sediments. The tubular concretions show central conduits running along the whole length, locally filled by sediments. The grain size within the concretions is homogeneous, both in the chimneys and planar concretions and irrespective of the bedding planes, suggesting a process of transport and homogenization prior to the cementation. Within the Enza river succession

  7. SEEPAGE, a new MODFLOW DRAIN package.

    PubMed

    Batelaan, O; De Smedt, F

    2004-01-01

    The prediction of the location of ground water discharge areas is a key aspect for the protection and (re)development of ground water-dependent wetlands. Ground water discharge areas can be simulated with MODFLOW using the DRAIN package by setting the drain level equal to the topography, while the conductance is mostly set to an arbitrary high value. However, conceptual and practical problems arise in the calculation of the ground water discharge by the DRAIN package as calculated water tables above the land surface, difficult parameterization of the conductance, and large water balance errors. To overcome these problems, a new SEEPAGE package for MODFLOW is proposed. The basic idea of this package is an adaptable constant head cell. It has a variable head, unless the ground water rises above the seepage level, in which case it has a constant head cell. The estimation of the ground water discharge location along a homogeneous, isotropic, linear sloping profile is used to verify the model and to compare it to the DRAIN solution. In an application to three basins in Belgium, it is shown that the SEEPAGE package can be used in combination with the DRAIN package in situations where an upper boundary for a free water table and additional resistance for drainage is required. It is clearly demonstrated that the identification and delineation of regional ground water discharge areas is more accurate using the SEEPAGE package.

  8. POST-PROCESSING ANALYSIS FOR THC SEEPAGE

    SciTech Connect

    Y. SUN

    2004-09-29

    This report describes the selection of water compositions for the total system performance assessment (TSPA) model of results from the thermal-hydrological-chemical (THC) seepage model documented in ''Drift-Scale THC Seepage Model'' (BSC 2004 [DIRS 169856]). The selection has been conducted in accordance with ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Post-Processing Analysis for THC Seepage) Report Integration'' (BSC 2004 [DIRS 171334]). This technical work plan (TWP) was prepared in accordance with AP-2.27Q, ''Planning for Science Activities''. Section 1.2.3 of the TWP describes planning information pertaining to the technical scope, content, and management of this report. The post-processing analysis for THC seepage (THC-PPA) documented in this report provides a methodology for evaluating the near-field compositions of water and gas around a typical waste emplacement drift as these relate to the chemistry of seepage, if any, into the drift. The THC-PPA inherits the conceptual basis of the THC seepage model, but is an independently developed process. The relationship between the post-processing analysis and other closely related models, together with their main functions in providing seepage chemistry information for the Total System Performance Assessment for the License Application (TSPA-LA), are illustrated in Figure 1-1. The THC-PPA provides a data selection concept and direct input to the physical and chemical environment (P&CE) report that supports the TSPA model. The purpose of the THC-PPA is further discussed in Section 1.2. The data selection methodology of the post-processing analysis (Section 6.2.1) was initially applied to results of the THC seepage model as presented in ''Drift-Scale THC Seepage Model'' (BSC 2004 [DIRS 169856]). Other outputs from the THC seepage model (DTN: LB0302DSCPTHCS.002 [DIRS 161976]) used in the P&CE (BSC 2004 [DIRS 169860

  9. Determining TOC in Waters

    ERIC Educational Resources Information Center

    Kehoe, Thomas J.

    1977-01-01

    The instrumental method for detecting total organic carbon (TOC) in water samples is detailed. The method's limitations are discussed and certain precautions that must be taken are emphasized. The subject of TOC versus COD and BOD is investigated and TOC is determined to be a valid indication of biological demand. (BT)

  10. Groundwater quality assessment/corrective action feasibility plan: New TNX Seepage Basin

    SciTech Connect

    Nichols, R.L.

    1989-12-05

    The New TNX Seepage Basin is located across River Road east of the TNX Area at the Savannah River Site. Currently the basin is out of service and is awaiting closure in accordance with the Consent Decree settled under Civil Act No. 1:85-2583. Groundwater monitoring data from the detection monitoring network around the New TNX Seepage Basin was recently analyzed using South Carolina Hazardous Waste Management Regulations R.61-79.264.92 methods to determine if groundwater downgradient of the New TNX Seepage Basin had been impacted. Results from the data analysis indicate that the groundwater has been impacted by inorganic constituents with no associated health risks. The impacts resulting from elevated levels of inorganic constituents, such as Mn, Na, and Total PO{sub 4} in the water table, do not pose a threat to human health and the environment.

  11. Hydrogeochemistry of seepage water collected within the Youngcheon diversion tunnel, Korea: source and evolution of SO4-rich groundwater in sedimentary terrain

    NASA Astrophysics Data System (ADS)

    Chae, Gi-Tak; Yun, Seong-Taek; Kim, Sang-Ryul; Hahn, Chan

    2001-06-01

    In the Youngcheon Diversion Tunnel area, South Korea, 46 samples of tunnel seepage water (TSW) and borehole groundwater were collected from areas with sedimentary rocks (mainly sandstone and shale) and were examined for hydrogeochemical characteristics. The measured SO4 concentrations range widely from 7·7 to 942·0 mg/l, and exceed the Korean Drinking Water Standard (200 mg/l) in about half the samples. The TDS (total dissolved solid) content generally is high (171-1461 mg/l) from more shale-rich formations and also reflects varying degrees of water-rock interaction. The water is classified into three groups: Ca SO4 type (61% of the samples collected), Ca SO4 HCO3 type (15%) and Ca HCO3 type (24%). The Ca HCO3 type water (mean concentrations=369 mg/l Ca, 148 mg/l HCO3 and 23 mg/l SO4) reflected the simple reaction between CO2-recharged water and calcite, whereas the more SO4-rich nature of Ca SO4 type water (mean concentrations=153 mg/l Ca, 66 mg/l HCOwater was enhanced by the diffusion of oxygenated air through the fractures related to the tunnel's construction. The subsequent outgassing of CO

  12. Solution of AntiSeepage for Mengxi River Based on Numerical Simulation of Unsaturated Seepage

    PubMed Central

    Ji, Youjun; Zhang, Linzhi; Yue, Jiannan

    2014-01-01

    Lessening the leakage of surface water can reduce the waste of water resources and ground water pollution. To solve the problem that Mengxi River could not store water enduringly, geology investigation, theoretical analysis, experiment research, and numerical simulation analysis were carried out. Firstly, the seepage mathematical model was established based on unsaturated seepage theory; secondly, the experimental equipment for testing hydraulic conductivity of unsaturated soil was developed to obtain the curve of two-phase flow. The numerical simulation of leakage in natural conditions proves the previous inference and leakage mechanism of river. At last, the seepage control capacities of different impervious materials were compared by numerical simulations. According to the engineering actuality, the impervious material was selected. The impervious measure in this paper has been proved to be effectible by hydrogeological research today. PMID:24707199

  13. The air-water exchange of C{sub 15}-C{sub 31} n-alkanes in a precipitation-dominated seepage lake.

    SciTech Connect

    Doskey, P. V.; Environmental Research

    2000-01-01

    The air-water exchange of semivolatile n-alkanes in Crystal Lake, a small precipitation-dominated seepage lake in northern Wisconsin, was investigated with modeling and mass balance approaches. The results suggest that atmospheric deposition contributes approximately 80% of the allochthonous input of n-alkanes to Crystal Lake. Atmospheric deposition accounts for about 50% of the total annual input of n-alkanes to Crystal Lake, and an additional 30% is contributed by in situ production of planktonic n-alkanes ({Sigma}C{sub 15}, C{sub 17}, C{sub 19}). Contributions to the particle dry flux of terrestrial n-alkanes ({Sigma}C{sub 25}, C{sub 27}, C{sub 29}, C{sub 31}) by pine pollen dispersal and by dry deposition of particles containing leaf waxes are similar in magnitude and constitute about 60% of the atmospheric input, with particle wet deposition being responsible for the remainder. Approximately 30% of the atmospheric input of the n-alkanes occurs during a two-week episode of pine pollen dispersal in spring. Concentration gradients between gaseous n-alkanes in the atmosphere and dissolved n-alkanes in the water column of Crystal Lake favor volatilization of n-alkanes from the lake surface; however, distributions of dissolved n-alkanes are characteristic of bacteria, and therefore are contained in organic matter and not available for air-water exchange. The estimated net atmospheric input of terrestrial n-alkanes is about 20% less than the settling sediment flux. Additional allochthonous sources of the terrestrial n-alkanes might include diffuse surface runoff or episodes of coarse-particle deposition. The discrepancies in the results from the modeling and mass balance approaches indicate that direct measurements of air-water exchange rates and measurements of the seasonal variations of particle size distributions in air and rain would greatly improve our ability to quantify air-water exchange rates of n-alkanes.

  14. H-Area Seepage Basins groundwater monitoring report

    SciTech Connect

    Not Available

    1992-09-01

    During second quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Plant. This report gives the results of the analyses of groundwater from the H-Area Seepage Basin.

  15. Flow rate logging seepage meter

    NASA Technical Reports Server (NTRS)

    Reay, William G. (Inventor); Walthall, Harry G. (Inventor)

    1996-01-01

    An apparatus for remotely measuring and logging the flow rate of groundwater seepage into surface water bodies. As groundwater seeps into a cavity created by a bottomless housing, it displaces water through an inlet and into a waterproof sealed upper compartment, at which point, the water is collected by a collection bag, which is contained in a bag chamber. A magnet on the collection bag approaches a proximity switch as the collection bag fills, and eventually enables the proximity switch to activate a control circuit. The control circuit then rotates a three-way valve from the collection path to a discharge path, enables a data logger to record the time, and enables a pump, which discharges the water from the collection bag, through the three-way valve and pump, and into the sea. As the collection bag empties, the magnet leaves the proximity of the proximity switch, and the control circuit turns off the pump, resets the valve to provide a collection path, and restarts the collection cycle.

  16. Seepage to Collection Gallery Near Seacoast

    NASA Astrophysics Data System (ADS)

    Hunt, B.

    1985-03-01

    Conformal mapping is used to obtain a solution for seepage to a collection gallery (a horizontal ditch or slotted pipe) that is parallel to a seacoast. The solution permits calculation of the gallery drawdown that is required to withdraw any given flow rate and also allows calculation of the maximum flow rate that can be abstracted without causing sea water intrusion. The results are applied to a numerical example.

  17. Identifying the Cause of Toxicity of a Saline Mine Water

    PubMed Central

    van Dam, Rick A.; Harford, Andrew J.; Lunn, Simon A.; Gagnon, Marthe M.

    2014-01-01

    Elevated major ions (or salinity) are recognised as being a key contributor to the toxicity of many mine waste waters but the complex interactions between the major ions and large inter-species variability in response to salinity, make it difficult to relate toxicity to causal factors. This study aimed to determine if the toxicity of a typical saline seepage water was solely due to its major ion constituents; and determine which major ions were the leading contributors to the toxicity. Standardised toxicity tests using two tropical freshwater species Chlorella sp. (alga) and Moinodaphnia macleayi (cladoceran) were used to compare the toxicity of 1) mine and synthetic seepage water; 2) key major ions (e.g. Na, Cl, SO4 and HCO3); 3) synthetic seepage water that were modified by excluding key major ions. For Chlorella sp., the toxicity of the seepage water was not solely due to its major ion concentrations because there were differences in effects caused by the mine seepage and synthetic seepage. However, for M. macleayi this hypothesis was supported because similar effects caused by mine seepage and synthetic seepage. Sulfate was identified as a major ion that could predict the toxicity of the synthetic waters, which might be expected as it was the dominant major ion in the seepage water. However, sulfate was not the primary cause of toxicity in the seepage water and electrical conductivity was a better predictor of effects. Ultimately, the results show that specific major ions do not clearly drive the toxicity of saline seepage waters and the effects are probably due to the electrical conductivity of the mine waste waters. PMID:25180579

  18. Identifying the cause of toxicity of a saline mine water.

    PubMed

    van Dam, Rick A; Harford, Andrew J; Lunn, Simon A; Gagnon, Marthe M

    2014-01-01

    Elevated major ions (or salinity) are recognised as being a key contributor to the toxicity of many mine waste waters but the complex interactions between the major ions and large inter-species variability in response to salinity, make it difficult to relate toxicity to causal factors. This study aimed to determine if the toxicity of a typical saline seepage water was solely due to its major ion constituents; and determine which major ions were the leading contributors to the toxicity. Standardised toxicity tests using two tropical freshwater species Chlorella sp. (alga) and Moinodaphnia macleayi (cladoceran) were used to compare the toxicity of 1) mine and synthetic seepage water; 2) key major ions (e.g. Na, Cl, SO4 and HCO3); 3) synthetic seepage water that were modified by excluding key major ions. For Chlorella sp., the toxicity of the seepage water was not solely due to its major ion concentrations because there were differences in effects caused by the mine seepage and synthetic seepage. However, for M. macleayi this hypothesis was supported because similar effects caused by mine seepage and synthetic seepage. Sulfate was identified as a major ion that could predict the toxicity of the synthetic waters, which might be expected as it was the dominant major ion in the seepage water. However, sulfate was not the primary cause of toxicity in the seepage water and electrical conductivity was a better predictor of effects. Ultimately, the results show that specific major ions do not clearly drive the toxicity of saline seepage waters and the effects are probably due to the electrical conductivity of the mine waste waters.

  19. Infiltration and Seepage Through Fractured Welded Tuff

    SciTech Connect

    T.A. Ghezzehei; P.F. Dobson; J.A. Rodriguez; P.J. Cook

    2006-06-20

    The Nopal I mine in Pena Blanca, Chihuahua, Mexico, contains a uranium ore deposit within fractured tuff. Previous mining activities exposed a level ground surface 8 m above an excavated mining adit. In this paper, we report results of ongoing research to understand and model percolation through the fractured tuff and seepage into a mined adit both of which are important processes for the performance of the proposed nuclear waste repository at Yucca Mountain. Travel of water plumes was modeled using one-dimensional numerical and analytical approaches. Most of the hydrologic properly estimates were calculated from mean fracture apertures and fracture density. Based on the modeling results, we presented constraints for the arrival time and temporal pattern of seepage at the adit.

  20. Seepage and seepage gradients in an homogeneous, isotropic aquifer with drains as a function of soil properties and flow region geometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seepage and seepage gradients are important parameters in soil erosion processes and water quality problems on agricultural land. Traditionally, surface overland flow is viewed as one of the major soil erosive agents on those areas. In recent years, the role of the subsurface flow regime is increasi...

  1. Chemical Properties of Pore Water and Sediment at Three Wetland Sites Near the F- and H-Area Seepage Basins, Savannah River Site

    SciTech Connect

    Friday, G.P.

    2001-05-15

    In 1980, vegetative stress and arboreal mortality in wetland plant communities down-gradient from the F- and H-Area seepage basins were detected using aerial imagery. By 1988, approximately six acres in H-Area and four acres in F-Area had been adversely impacted. Today, wetland plant communities have become well established at the H-Area tree-kill zone.

  2. Modeling Coupled Evaporation and Seepage in Ventilated Cavities

    SciTech Connect

    T. Ghezzehei; R. Trautz; S. Finsterle; P. Cook; C. Ahlers

    2004-07-01

    Cavities excavated in unsaturated geological formations are important to activities such as nuclear waste disposal and mining. Such cavities provide a unique setting for simultaneous occurrence of seepage and evaporation. Previously, inverse numerical modeling of field liquid-release tests and associated seepage into cavities were used to provide seepage-related large-scale formation properties by ignoring the impact of evaporation. The applicability of such models was limited to the narrow range of ventilation conditions under which the models were calibrated. The objective of this study was to alleviate this limitation by incorporating evaporation into the seepage models. We modeled evaporation as an isothermal vapor diffusion process. The semi-physical model accounts for the relative humidity, temperature, and ventilation conditions of the cavities. The evaporation boundary layer thickness (BLT) over which diffusion occurs was estimated by calibration against free-water evaporation data collected inside the experimental cavities. The estimated values of BLT were 5 to 7 mm for the open underground drifts and 20 mm for niches closed off by bulkheads. Compared to previous models that neglected the effect of evaporation, this new approach showed significant improvement in capturing seepage fluctuations into open cavities of low relative humidity. At high relative-humidity values (greater than 85%), the effect of evaporation on seepage was very small.

  3. Impact of Rock Bolts on Seepage

    SciTech Connect

    F. C. Ahlers

    2001-06-01

    Characterization of seepage into drifts in unsaturated fractured tuff is a key factor for assessing the long-term viability of the proposed high level nuclear waste repository at Yucca Mountain. Rock bolts are among the methods proposed for ground control in the emplacement drifts. They may provide a conduit whereby percolating water that would otherwise bypass the drift will seep into the drift. The objective of this study is to assess the impact that the use of rock bolts may have on seepage. The impact of rock bolts on seepage is studied using a numerical model that is finely discretized around the rock bolt. There are several sources of uncertainty and variability with respect to the flow system around the drift and rock bolt. There is uncertainty about the capillary strength of the fractures around the drift. There is also uncertainty about how the permeability and capillary strength of the grout used to cement the steel rock bolts into the bolt holes will change over time. There is variability expected in the percolation rates incident upon the drifts depending on location. The uncertainty and variability of these parameters are approached by evaluating the rock bolt impact over a range of values for several model parameters. It is also important to consider where the last fracture capable of carrying flow away from the rock bolt intersects the rock bolt. Three models are used where the last fracture is 0, 10 and 50 cm above the drift.

  4. Role of tectonic stress in seepage evolution along the gas hydrate-charged Vestnesa Ridge, Fram Strait

    NASA Astrophysics Data System (ADS)

    Plaza-Faverola, A.; Bünz, S.; Johnson, J. E.; Chand, S.; Knies, J.; Mienert, J.; Franek, P.

    2015-02-01

    Methane expulsion from the world ocean floor is a broadly observed phenomenon known to be episodic. Yet the processes that modulate seepage remain elusive. In the Arctic offshore west Svalbard, for instance, seepage at 200-400 m water depth may be explained by ocean temperature-controlled gas hydrate instabilities at the shelf break, but additional processes are required to explain seepage in permanently cold waters at depths >1000 m. We discuss the influence of tectonic stress on seepage evolution along the ~100 km long hydrate-bearing Vestnesa Ridge in Fram Strait. High-resolution P-Cable 3-D seismic data revealed fine-scale (>10 m width) near-vertical faults and fractures controlling seepage distribution. Gas chimneys record multiple seepage events coinciding with glacial intensification and active faulting. The faults document the influence of nearby tectonic stress fields in seepage evolution along this deepwater gas hydrate system for at least the last ~2.7 Ma.

  5. Hydrological and chemical estimates of the water balance of a closed-basin lake in north central Minnesota

    USGS Publications Warehouse

    LaBaugh, J.W.; Winter, T.C.; Rosenberry, D.O.; Schuster, P.F.; Reddy, M.M.; Aiken, G.R.

    1997-01-01

    Chemical mass balances for sodium, magnesium, chloride, dissolved organic carbon, and oxygen 18 were used to estimate groundwater seepage to and from Williams Lake, Minnesota, over a 15-month period, from April 1991 through June 1992. Groundwater seepage to the lake and seepage from the lake to groundwater were determined independently using a flow net approach using data from water table wells installed as part of the study. Hydrogeological analysis indicated groundwater seepage to the lake accounted for 74% of annual water input to the lake; the remainder came from atmospheric precipitation, as determined from a gage in the watershed and from nearby National Weather Service gages. Seepage from the lake accounted for 69% of annual water losses from the lake; the remainder was removed by evaporation, as determined by the energy budget method. Calculated annual water loss exceeded calculated annual water gain, and this imbalance was double the value of the independently measured decrease in lake volume. Seepage to the lake determined from oxygen 18 was larger (79% of annual water input) than that determined from the flow net approach and made the difference between calculated annual water gain and loss consistent with the independently measured decrease in lake volume. Although the net difference between volume of seepage to the lake and volume of seepage from the lake was 1% of average lake volume, movement of water into and out of the lake by seepage represented an annual exchange of groundwater with the lake equal to 26-27% of lake volume. Estimates of seepage to the lake from sodium, magnesium, chloride, and dissolved organic carbon did not agree with the values determined from flow net approach or oxygen 18. These results indicated the importance of using a combination of hydrogeological and chemical approaches to define volume of seepage to and from Williams Lake and identify uncertainties in chemical fluxes.

  6. Liquid chromatographic determination of water

    DOEpatents

    Fortier, Nancy E.; Fritz, James S.

    1990-11-13

    A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present.

  7. Liquid chromatographic determination of water

    DOEpatents

    Fortier, N.E.; Fritz, J.S.

    1990-11-13

    A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present. 1 fig.

  8. Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin, With Special Emphasis on Responses of an Oligotrophic Seepage Lake to Changes in Phosphorus Loading and Water Level

    USGS Publications Warehouse

    Robertson, Dale M.; Rose, William J.; Juckem, Paul F.

    2009-01-01

    Whitefish Lake, which is officially named Bardon Lake, is an oligotrophic, soft-water seepage lake in northwestern Wisconsin, and classified by the Wisconsin Department of Natural Resources as an Outstanding Resource Water. Ongoing monitoring of the lake demonstrated that its water quality began to degrade (increased phosphorus and chlorophyll a concentrations) around 2002 following a period of high water level. To provide a better understanding of what caused the degradation in water quality, and provide information to better understand the lake and protect it from future degradation, the U.S. Geological Survey did a detailed study from 2004 to 2008. The goals of the study were to describe the past and present water quality of the lake, quantify water and phosphorus budgets for the lake, simulate the potential effects of changes in phosphorus inputs on the lake's water quality, analyze changes in the water level in the lake since 1900, and relate the importance of changes in climate and changes in anthropogenic (human-induced) factors in the watershed to the water quality of the lake. Since 1998, total phosphorus concentrations increased from near the 0.005-milligrams per liter (mg/L) detection limit to about 0.010 mg/L in 2006, and then decreased slightly in 2007-08. During this time, chlorophyll a concentrations and Secchi depths remained relatively stable at about 1.5 micrograms per liter (ug/L) and 26 feet, respectively. Whitefish Lake is typically classified as oligotrophic. Because the productivity in Whitefish Lake is limited by phosphorus, phosphorus budgets were constructed for the lake. Because it was believed that much of its phosphorus comes from the atmosphere, phosphorus deposition was measured in this study. Phosphorus input from the atmosphere was greater than computed based on previously reported wetfall phosphorus concentrations. The concentrations and deposition rates can be used to estimate atmospheric loading in future lake studies. The

  9. Seepage into an Underground Opening Constructed in Unsaturated Fractured Rock Under Evaporative Conditions

    SciTech Connect

    R. C. Trautz; Joseph S. Y. Wang

    2001-06-07

    Liquid-release tests, performed in boreholes above an underground opening constructed in unsaturated fractured rock, are used in this study to evaluate seepage into a waste emplacement drift. Evidence for the existence of a capillary barrier at the ceiling of the drift is presented, based on field observations (including spreading of the wetting front across the ceiling and water movement up fractures exposed in the ceiling before seepage begins). The capillary barrier mechanism has the potential to divert water around the opening, resulting in no seepage when the percolation flux is at or below the seepage threshold flux. Liquid-release tests are used to demonstrate that a seepage threshold exists and to measure the magnitude of the seepage threshold flux for three test zones that seeped. The seepage data are interpreted using analytical techniques to estimate the test-specific strength of the rock capillary forces ({alpha}{sup -1}) that prevent water from seeping into the drift. Evaporation increases the seepage threshold flux making it more difficult for water to seep into the drift and producing artificially inflated {alpha}{sup -1} values. With adjustments for evaporation, the minimum test-specific threshold is 1,600 mm/yr with a corresponding {alpha}{sup -1} of 0.027 m.

  10. Temporal constraints on hydrate-controlled methane seepage off Svalbard.

    PubMed

    Berndt, C; Feseker, T; Treude, T; Krastel, S; Liebetrau, V; Niemann, H; Bertics, V J; Dumke, I; Dünnbier, K; Ferré, B; Graves, C; Gross, F; Hissmann, K; Hühnerbach, V; Krause, S; Lieser, K; Schauer, J; Steinle, L

    2014-01-17

    Methane hydrate is an icelike substance that is stable at high pressure and low temperature in continental margin sediments. Since the discovery of a large number of gas flares at the landward termination of the gas hydrate stability zone off Svalbard, there has been concern that warming bottom waters have started to dissociate large amounts of gas hydrate and that the resulting methane release may possibly accelerate global warming. Here, we corroborate that hydrates play a role in the observed seepage of gas, but we present evidence that seepage off Svalbard has been ongoing for at least 3000 years and that seasonal fluctuations of 1° to 2°C in the bottom-water temperature cause periodic gas hydrate formation and dissociation, which focus seepage at the observed sites.

  11. Geoelectric monitoring of seepage in porous media with engineering applications to earthen dams

    NASA Astrophysics Data System (ADS)

    Ikard, Scott

    A monitoring methodology is developed for investigating seepage and internal erosion in earthen dams with time-lapse measurements of self-potential anomalies associated with conservative salt and non-conservative heat tracer migration in the subsurface. The method allows for 1) detecting seepage zones in earthen dams and determining the preferential flow paths through seepage zones in a non-invasive manner from the ground surface, 2) monitoring the transient evolution of seepage path geometry, flow velocity, and permeability in real-time if high frequency measurements can be made, and 3) long-term non-invasive monitoring with wired or wireless sensors The method is first theoretically developed and tested in a laboratory using a conservative tracer, and then demonstrated at a 12 m high, 100 m long leaking earthen dam with complex, unknown seepage paths. The method is shown to be capable of rapidly detecting seepage zones discovered during a reconnaissance survey, and delineates the predominant seepage directions through the dam from the time-lapse self-potential anomalies. The time-lapse monitoring approach ensures improved spatial resolution, increased measurement frequencies, and improved data analysis capabilities relative to traditional approaches to seepage detection, and a cost-reduction for the application of this methodology is anticipated to follow advancements in wireless sensing and monitoring technologies. This method is designed to be a more cost-effective means of interrogating earthen dams and levees to answer questions such as: Is the dam safe? What are the geometries of the seepage zones inside of the dam, and over what spatial scale does anomalous seepage occur? What are preferential paths through the seepage zones? Is internal erosion actively occurring? At what rates are the geometries, permeabilities and flow rates of preferential seepage paths evolving?

  12. An evaluation of seepage gains and losses in Indian Creek Reservoir, Ada County, Idaho, April 2010–November 2011

    USGS Publications Warehouse

    Williams, Marshall L.; Etheridge, Alexandra B.

    2013-01-01

    The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources, conducted an investigation on Indian Creek Reservoir, a small impoundment in east Ada County, Idaho, to quantify groundwater seepage into and out of the reservoir. Data from the study will assist the Idaho Water Resources Department’s Comprehensive Aquifer Management Planning effort to estimate available water resources in Ada County. Three independent methods were utilized to estimate groundwater seepage: (1) the water-budget method; (2) the seepage-meter method; and (3) the segmented Darcy method. Reservoir seepage was quantified during the periods of April through August 2010 and February through November 2011. With the water-budget method, all measureable sources of inflow to and outflow from the reservoir were quantified, with the exception of groundwater; the water-budget equation was solved for groundwater inflow to or outflow from the reservoir. The seepage-meter method relies on the placement of seepage meters into the bottom sediments of the reservoir for the direct measurement of water flux across the sediment-water interface. The segmented-Darcy method utilizes a combination of water-level measurements in the reservoir and in adjacent near-shore wells to calculate water-table gradients between the wells and the reservoir within defined segments of the reservoir shoreline. The Darcy equation was used to calculate groundwater inflow to and outflow from the reservoir. Water-budget results provided continuous, daily estimates of seepage over the full period of data collection, while the seepage-meter and segmented Darcy methods provided instantaneous estimates of seepage. As a result of these and other difference in methodologies, comparisons of seepage estimates provided by the three methods are considered semi-quantitative. The results of the water-budget derived estimates of seepage indicate seepage to be seasonally variable in terms of the direction and magnitude

  13. Determination of radium in water

    USGS Publications Warehouse

    Barker, Franklin Butt; Johnson, J.O.

    1964-01-01

    Radium isotopes are common radioactive constituents of natural waters. The concentration of radium-226 in potable water is of particular significance because this isotope is generally considered the most hazardous of all radionuclides with respect to ingestion. The approximate concentration of radium-226 is determined after coprecipitating radium with barium sulfate. The short-lived daughters of radium are allowed to grow for 10-12 days, then the alpha activity of the precipitate is measured and compared with that of a precipitate containing a known amount of radium-226. Concentrations of the individual alpha-emitting isotopes of radium-223, radium-224, and radium-226, are determined by coprecipitating radium first with lead sulfate, then with barium chloride, and finally with barium sulfate. This final precipitate is initially free of other alpha-emitting nuclides, thus permitting the isotopic composition to be determined by measuring the growth and decay of the alpha activity of the precipitate.

  14. H-Area Seepage Basins: Groundwater quality assessment report, Savannah River Site. Second quarter, 1990

    SciTech Connect

    Not Available

    1990-09-01

    During the second quarter of 1990 the wells which make up the H-Area Seepage Basins (H-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, nonvolatile beta, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, nonvolatile beta, trichloroethylene (TCE), tetrachloroethylene, lead, cadmium, arsenic, and total radium. Concentrations of at least one of the following constituents: tritium, nitrate, total radium, gross alpha, nonvolatile beta, mercury, lead, cadmium, trichloroethylene chromium, and arsenic in excess of the primary drinking water standard (PDWS) were observed in at least one well monitoring the H-Area Seepage Basins. Elevated levels of tritium above the PDWS were exhibited in seventy-seven of the 105 (73%) groundwater monitoring wells. Elevated levels of nitrate in excess of the PDWS were exhibited in forty-four of the 105 (42%) monitoring wells.

  15. H-Area Seepage Basins: Groundwater quality assessment report, Savannah River Site

    SciTech Connect

    Not Available

    1990-09-01

    During the second quarter of 1990 the wells which make up the H-Area Seepage Basins (H-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, nonvolatile beta, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, nonvolatile beta, trichloroethylene (TCE), tetrachloroethylene, lead, cadmium, arsenic, and total radium. Concentrations of at least one of the following constituents: tritium, nitrate, total radium, gross alpha, nonvolatile beta, mercury, lead, cadmium, trichloroethylene chromium, and arsenic in excess of the primary drinking water standard (PDWS) were observed in at least one well monitoring the H-Area Seepage Basins. Elevated levels of tritium above the PDWS were exhibited in seventy-seven of the 105 (73%) groundwater monitoring wells. Elevated levels of nitrate in excess of the PDWS were exhibited in forty-four of the 105 (42%) monitoring wells.

  16. Drift natural convection and seepage at the Yucca Mountain repository

    NASA Astrophysics Data System (ADS)

    Halecky, Nicholaus Eugene

    The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock, from the hot drift center to the cool drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water- induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.

  17. Seepage investigation of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, 2014

    USGS Publications Warehouse

    Briody, Alyse C.; Robertson, Andrew J.; Thomas, Nicole

    2016-03-22

    Seepage investigations have been conducted annually by the U.S. Geological Survey from 1988 to 1998 and from 2004 to the present (2014) along a 64-mile reach of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, as part of the Mesilla Basin monitoring program. Results of the investigation conducted in 2014 are presented in this report. The 2014 seepage investigation was conducted on February 11, 2014, during the low-flow conditions of the non-irrigation season. During the 2014 investigation, discharge was measured at 23 sites along the main-stem Rio Grande and 19 inflow sites within the study reach. Because of extended drought conditions affecting the basin, many sites along the Rio Grande (17 main-stem and 9 inflow) were observed to be dry in February 2014. Water-quality samples were collected during the seepage investigation at sites with flowing water as part of a long-term monitoring effort in the region.Net seepage gain or loss was computed for each subreach (the interval between two adjacent measurement locations along the river) by subtracting the discharge measured at the upstream location from the discharge measured at the closest downstream location along the river and then subtracting any inflow to the river within the subreach. An estimated gain or loss was determined to be meaningful when it exceeded the cumulative measurement uncertainty associated with the net seepage computation. The cumulative seepage loss in the 64-mile study reach in 2014 was 16.0 plus or minus 2.9 cubic feet per second.

  18. Method for estimating spatially variable seepage loss and hydraulic conductivity in intermittent and ephemeral streams

    USGS Publications Warehouse

    Niswonger, R.G.; Prudic, D.E.; Fogg, G.E.; Stonestrom, D.A.; Buckland, E.M.

    2008-01-01

    A method is presented for estimating seepage loss and streambed hydraulic conductivity along intermittent and ephemeral streams using streamflow front velocities in initially dry channels. The method uses the kinematic wave equation for routing streamflow in channels coupled to Philip's equation for infiltration. The coupled model considers variations in seepage loss both across and along the channel. Water redistribution in the unsaturated zone is also represented in the model. Sensitivity of the streamflow front velocity to parameters used for calculating seepage loss and for routing streamflow shows that the streambed hydraulic conductivity has the greatest sensitivity for moderate to large seepage loss rates. Channel roughness, geometry, and slope are most important for low seepage loss rates; however, streambed hydraulic conductivity is still important for values greater than 0.008 m/d. Two example applications are presented to demonstrate the utility of the method. Copyright 2008 by the American Geophysical Union.

  19. Remote semi-continuous flow rate logging seepage meter

    NASA Technical Reports Server (NTRS)

    Reay, William G.; Walthall, Harry G.

    1991-01-01

    The movement of groundwater and its associated solutes from upland regions was implicated in the degradation of receiving surface water bodies. Current efforts to directly measure this influx of water incorporate manually operated seepage meters which are hindered by severe limitations. A prototype seepage meter was developed by NASA Langley Research Center and Virginia Polytechnic Institute and State University that will allow for the semi-continuous collection and data logging of seepage flux across the sediment water interface. The meter is designed to operate at depths to 40 meters, and alleviate or minimize all disadvantages associated with traditional methods while remaining cost effective. The unit was designed to operate independently for time periods on the order of weeks with adjustable sample sequences depending upon hydrologic conditions. When used in conjunction with commercially available pressure transducers, this seepage meter allows for correlations to be made between groundwater discharge and tidal/sea state conditions in coastal areas. Field data from the Chesapeake Bay and Florida Bay systems are presented.

  20. Incorporating seepage losses into the unsteady streamflow equations for simulating intermittent flow along mountain front streams

    USGS Publications Warehouse

    Niswonger, R.G.; Prudic, D.E.; Pohll, G.; Constantz, J.

    2005-01-01

    Seepage losses along numerous mountain front streams that discharge intermittently onto alluvial fans and piedmont alluvial plains are an important source of groundwater in the Basin and Range Province of the Western United States. Determining the distribution of seepage loss along mountain front streams is important when assessing groundwater resources of the region. Seepage loss along a mountain front stream in northern Nevada was evaluated using a one-dimensional unsteady streamflow model. Seepage loss was incorporated into the spatial derivatives of the streamflow equations. Because seepage loss from streams is dependent on stream depth, wetted perimeter, and streambed properties, a two-dimensional variably saturated flow model was used to develop a series of relations between seepage loss and stream depth for each reach. This method works when streams are separated from groundwater by variably saturated sediment. Two periods of intermittent flow were simulated to evaluate the modeling approach. The model reproduced measured flow and seepage losses along the channel. Seepage loss in the spring of 2000 was limited to the upper reaches on the alluvial plain and totaled 196,000 m3, whereas 64% of the seepage loss in the spring of 2004 occurred at the base of the alluvial plain and totaled 273,000 m3. A greater seepage loss at the base of the piedmont alluvial plain is attributed to increased streambed hydraulic conductivity caused by less armoring of the channel. The modeling approach provides a method for quantifying and distributing seepage loss along mountain front streams that cross alluvial fans or piedmont alluvial plains. Copyright 2005 by the American Geophysical Union.

  1. Geophysical investigation of seepage beneath an earthen dam.

    PubMed

    Ikard, S J; Rittgers, J; Revil, A; Mooney, M A

    2015-01-01

    A hydrogeophysical survey is performed at small earthen dam that overlies a confined aquifer. The structure of the dam has not shown evidence of anomalous seepage internally or through the foundation prior to the survey. However, the surface topography is mounded in a localized zone 150 m downstream, and groundwater discharges from this zone periodically when the reservoir storage is maximum. We use self-potential and electrical resistivity tomography surveys with seismic refraction tomography to (1) determine what underlying hydrogeologic factors, if any, have contributed to the successful long-term operation of the dam without apparent indicators of anomalous seepage through its core and foundation; and (2) investigate the hydraulic connection between the reservoir and the seepage zone to determine whether there exists a potential for this success to be undermined. Geophysical data are informed by hydraulic and geotechnical borehole data. Seismic refraction tomography is performed to determine the geometry of the phreatic surface. The hydro-stratigraphy is mapped with the resistivity data and groundwater flow patterns are determined with self-potential data. A self-potential model is constructed to represent a perpendicular profile extending out from the maximum cross-section of the dam, and self-potential data are inverted to recover the groundwater velocity field. The groundwater flow pattern through the aquifer is controlled by the bedrock topography and a preferential flow pathway exists beneath the dam. It corresponds to a sandy-gravel layer connecting the reservoir to the downstream seepage zone.

  2. Electric-field response based experimental investigation of unsaturated soil slope seepage

    NASA Astrophysics Data System (ADS)

    Geng, Jishi; Sun, Qiang; Zhang, Yuchun; Yan, Changgen; Zhang, Weiqiang

    2017-03-01

    Rainfall is one of the important factors causing the failure of slope, such as the occurrence of transverse cracks and localized slumps. The process of rainfall seepage was studied with an indoor soil slope model based on the Network Parallel Electrical Method. The responses of geoelectric-field parameters were analyzed to infer the evolution process of rainfall seepage path. The variations of geoelectric-field parameters also contribute to our understanding of the behavior of groundwater seepage. The results show that the seepage velocity and seepage position of groundwater can be obtained according to the exciting current and primary field potential response characteristics of seepage field. The primary field potential, exciting current, spontaneous potential and apparent resistivity are sensitive to the water flow. When the position of the seepage surface reaches a certain electrode, the spontaneous potential, primary field potential and exciting current rapidly increase, while the apparent resistivity decreases gradually. The result of apparent resistivity can reflect the variation of the water content in the 3D structural soil slope and the position of infiltration surface. The results of study can provide the theoretical basis for studying the behavior of moisture flow in soil slope under rainfall condition.

  3. Simulating seepage into mine shafts and tunnels with MODFLOW.

    PubMed

    Zaidel, Jacob; Markham, Bradley; Bleiker, David

    2010-01-01

    In cases when an equivalent porous medium assumption is suitable for simulating groundwater flow in bedrock aquifers, estimation of seepage into underground mine workings (UMWs) can be achieved by specifying MODFLOW drain nodes at the contact between water bearing rock and dewatered mine openings. However, this approach results in significant numerical problems when applied to simulate seepage into an extensive network of UMWs, which often exist at the mine sites. Numerical simulations conducted for individual UMWs, such as a vertical shaft or a horizontal drift, showed that accurate prediction of seepage rates can be achieved by either applying grid spacing that is much finer than the diameter/width of the simulated openings (explicit modeling) or using coarser grid with cell sizes exceeding the characteristic width of shafts or drifts by a factor of 3. Theoretical insight into this phenomenon is presented, based on the so-called well-index theory. It is demonstrated that applying this theory allows to minimize numerical errors associated with MODFLOW simulation of seepage into UMWs on a relatively coarse Cartesian grid. Presented examples include simulated steady-state groundwater flow from homogeneous, heterogeneous, and/or anisotropic rock into a vertical shaft, a horizontal drift/cross-cut, a ramp, two parallel drifts, and a combined system of a vertical shaft connected to a horizontal drift.

  4. Shallow bedrock limits groundwater seepage-based headwater climate refugia

    USGS Publications Warehouse

    Briggs, Martin; Lane, John; Snyder, Craig D.; White, Eric A.; Johnson, Zachary; Nelms, David L.; Hitt, Nathaniel P.

    2017-01-01

    Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive to seasonal and long-term air temperature dynamics. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We employ rapid, cost-effective passive seismic measurements to evaluate the variable thickness of the shallow colluvial and alluvial aquifer sediments along a headwater stream supporting cold water-dependent brook trout (Salvelinus fontinalis) in Shenandoah National Park, VA, USA. Using a mean depth to bedrock of 2.6 m, numerical models predicted strong sensitivity of shallow aquifer temperature to the downward propagation of surface heat. The annual temperature dynamics (annual signal amplitude attenuation and phase shift) of potential seepage sourced from the shallow modeled aquifer were compared to several years of paired observed stream and air temperature records. Annual stream water temperature patterns were found to lag local air temperature by ∼8–19 d along the stream corridor, indicating that thermal exchange between the stream and shallow groundwater is spatially variable. Locations with greater annual signal phase lag were also associated with locally increased amplitude attenuation, further suggestion of year-round buffering of channel water temperature by groundwater seepage. Numerical models of shallow groundwater temperature that incorporate regional expected climate warming trends indicate that the summer cooling capacity of this groundwater seepage will be reduced over time, and lower-elevation stream sections may no longer serve as larger

  5. Evaluation of seepage from Chester Morse Lake and Masonry Pool, King County, Washington

    USGS Publications Warehouse

    Hidaka, F.T.; Garrett, Arthur Angus

    1967-01-01

    Hydrologic data collected in the Cedar and Snoqualmie River basins on the west slope of the Cascade Range have been analyzed to determine the amount of water lost by seepage from Chester Morse Lake and Masonry Pool and the. consequent gain by seepage to the Cedar and South Fork Snoqualmie Rivers. For water years 1957-64, average losses were about 220 cfs (cubic feet per second) while average gains were about 180 cfs in the Cedar River and 50 cfs in the South Fork Snoqualmie River. Streamflow and precipitation data for water years 1908-26 and 1930-F2 indicate that a change in runoff regimen occurred in Cedar and South Fork Snoqualmie Rivers after the Boxley Creek washout in December 1918. For water years 1919-26 and 1930-32, the flow of Cedar River near Landsburg averaged about 80 cfs less than it would have if the washout had not occurred. In contrast, the flow of South Fork Snoqualmie River at North Bend averaged about 60 cfs more than it would have.

  6. Utilizing Continuous Resistivity Profiling for Assessment and Characterization of Canal Seepage in El Paso's Lower Valley Irrigation Network System

    NASA Astrophysics Data System (ADS)

    Brown, W. A.; Sheng, Z.

    2009-12-01

    Annually, billions of gallons of water are lost through seepage along sections of the irrigation network. To conserve water, El Paso County Water Improvement District has been assessing seepage losses and investigating measures for reducing such losses. Resistivity techniques were used to identify areas of high seepage and provide information on locations along canals that need to be structurally modified in an effort to curb water lost through seepage. Several half mile sections were selected along canals with varying seepage rates to conduct electric resistivity surveys in order generate soil profiles during the non-irrigation and irrigation seasons. Two different multiple channel resistivity meters (The“OhmMapper and the Super Sting R8”) were used, which both allow a vertical resistivity profile to be collected using a single current transmission. The results presented are preliminary and we believe that upon completion findings will serve multiple purposes. Firstly, a better understanding of seepage patterns, seepage rate and its spatial variation can be obtained. Secondly, our findings could be used to produce geological profiles associated with seepage areas which will enable the irrigation district to develop guidelines for improving delivery efficiency, especially during drought. And thirdly, our results will be transferable to other areas of the state and will have a positive impact on the environment and the overall quality of life.

  7. The geochemistry characteristic and dating of cold seepage carbonates of the Pearl River Mouth Basin, eastern of South China Sea

    NASA Astrophysics Data System (ADS)

    Fang, Yunxin; Fu, Shaoying

    2015-04-01

    Cold seepage carbonates are usually formed by the interaction of methane oxidizing archaea, sulfate reducing bacteria and cold seepage which contain abundant venting hydrocarbon gases. The presence of cold seepage carbonates on the seabed is one of the evidences that the area exist venting hydrocarbon gases, which are usually result by the dissociation of gas hydrate. The cold seepage property and fluid flow rate can influence the oxidation-deoxidation environment of the bottom water and sediment. Many previous studies focused on the mineral composition, microstructure, elemental composition, isotope composition of the cold seepage carbonates and isotopic dating for the cold seepage carbonates. The isotopic dating for the cold seepage carbonates can provide the information of the gas hydrate formation and dissociation in some area of the South China Sea. High precision TIMS-U dating and 14C dating are used as routine method for the dating of the Quaternary carbonates and fossils. The cold seepage carbonates in the study include the samples collected by ROV on the seabed and the drilling for gas hydrate in the Pearl River Mouth Basin, eastern of the South China Sea. The authigenic carbonate occurred in different depth in the A, B and C drilling site. They may be represent different events of gas hydrate formation and dissociation in the Quaternary. The dating study for all the cold seepage carbonates can provide the relative accurate eras of the gas hydrate dissociation events in certain area of the South China Sea.

  8. Three-dimensional imaging, change detection, and stability assessment during the centerline trench levee seepage experiment using terrestrial light detection and ranging technology, Twitchell Island, California, 2012

    USGS Publications Warehouse

    Bawden, Gerald W.; Howle, James; Bond, Sandra; Shriro, Michelle; Buck, Peter

    2014-01-01

    A full scale field seepage test was conducted on a north-south trending levee segment of a now bypassed old meander belt on Twitchell Island, California, to understand the effects of live and decaying root systems on levee seepage and slope stability. The field test in May 2012 was centered on a north-south trench with two segments: a shorter control segment and a longer seepage test segment. The complete length of the trench area measured 40.4 meters (m) near the levee centerline with mature trees located on the waterside and landside of the levee flanks. The levee was instrumented with piezometers and tensiometers to measure positive and negative porewater pressures across the levee after the trench was flooded with water and held at a constant hydraulic head during the seepage test—the results from this component of the experiment are not discussed in this report. We collected more than one billion three-dimensional light detection and ranging (lidar) data points before, during, and after the centerline seepage test to assess centimeter-scale stability of the two trees and the levee crown. During the seepage test, the waterside tree toppled (rotated 20.7 degrees) into the water. The landside tree rotated away from the levee by 5 centimeters (cm) at a height of 2 m on the tree. The paved surface of the levee crown had three regions that showed subsidence on the waterside of the trench—discussed as the northern, central, and southern features. The northern feature is an elongate region that subsided 2.1 cm over an area with an average width of 1.35 m that extends 15.8 m parallel to the trench from the northern end of the trench to just north of the trench midpoint, and is associated with a crack 1 cm in height that formed during the seepage test on the trench wall. The central subsidence feature is a semicircular region on the waterside of the trench that subsided by as much as 6.2 cm over an area 3.4 m wide and 11.2 m long. The southern feature is an elongate

  9. Fluid venting and seepage at accretionary ridges: the Four Way Closure Ridge offshore SW Taiwan

    NASA Astrophysics Data System (ADS)

    Klaucke, Ingo; Berndt, Christian; Crutchley, Gareth; Chi, Wu-Cheng; Lin, Saulwood; Muff, Sina

    2016-06-01

    Within the accretionary prism offshore SW Taiwan, widespread gas hydrate accumulations are postulated to occur based on the presence of a bottom simulating reflection. Methane seepage, however, is also widespread at accretionary ridges offshore SW Taiwan and may indicate a significant loss of methane bypassing the gas hydrate system. Four Way Closure Ridge, located in 1,500 m water depth, is an anticlinal ridge that would constitute an ideal trap for methane and consequently represents a site with good potential for gas hydrate accumulations. The analysis of high-resolution bathymetry, deep-towed sidescan sonar imagery, high-resolution seismic profiling and towed video observations of the seafloor shows that Four Way Closure Ridge is and has been a site of intensive methane seepage. Continuous seepage is mainly evidenced by large accumulations of authigenic carbonate precipitates, which appear to be controlled by the creation of fluid pathways through faulting. Consequently, Four Way Closure Ridge is not a closed system in terms of fluid migration and seepage. A conceptual model of the evolution of gas hydrates and seepage at accretionary ridges suggests that seepage is common and may be a standard feature during the geological development of ridges in accretionary prisms. The observation of seafloor seepage alone is therefore not a reliable indicator of exploitable gas hydrate accumulations at depth.

  10. Seepage and settlement monitoring for earth embankment dams using fully distributed sensing along optical fibers

    NASA Astrophysics Data System (ADS)

    Zhu, P. Y.; Zhou, Y.; Thévenaz, Luc; Jiang, G. L.

    2008-12-01

    A method for seepage and settlement monitoring in earth embankment dams using fully distributed sensing along optical fibres is proposed. A model is developed for simulating and monitoring seepage and settlement systems. This model relates the strains and the temperature changes to the fiber Brillouin gain spectrum in the embankment dam embedding the optical fiber sensors. The model consists of two parts. Submodel 1 addresses the simulation of seepage inside the embankment dam. Submodel 2 relates the measurement of the fiber Brillouin gain spectrum to the changes in temperature and strain inside the embankment dam. Both the changes in temperature and strain during the process are used to reveal serious seepages and settlements occurring inside the embankment dam. The continuously decreasing temperature curve shows an abrupt dramatic increasing rate, which shows that the change is not caused by the temperature of the seepage water but the strain. In this paper, as an example, a model filled with the soil from Yellow River is built and bare optical fibers are embedded under different soil layers near the seepage path. The simulated seepage flows under various flow rates are monitored using the optical fibers and measured by a DiTeSt -STA202 distributed temperature and strain analyzer. A partial settlement within the embankment dam model is observed.

  11. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    SciTech Connect

    Dobson, Patrick F.; Cook, Paul J.; Ghezzehei, Teamrat A.; Rodriguez, J. Alfredo; Villalba, Lourdes; de la Garza, Rodrigo

    2008-10-25

    An integrated field, laboratory, and modeling study of the Pena Blanca (Chihuahua, Mexico) natural analogue site is being conducted to evaluate processes that control the mobilization and transport of radionuclides from a uranium ore deposit. One component of this study is an evaluation of the potential for radionuclide transport through the unsaturated zone (UZ) via a seepage study in an adit at the Nopal I uranium mine, excavated 10 m below a mined level surface. Seasonal rainfall on the exposed level surface infiltrates into the fractured rhyolitic ash-flow tuff and seeps into the adit. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage within the Nopal I +00 adit. Monitoring of seepage within the adit between April 2005 and December 2006 indicates that seepage is highly heterogeneous with respect to time, location, and quantity. Within the back adit area, a few zones where large volumes of water have been collected are linked to fast flow path fractures (0-4 h transit times) presumably associated with focused flow. In most locations, however, there is a 1-6 month time lag between major precipitation events and seepage within the adit, with longer residence times observed for the front adit area. Seepage data obtained from this study will be used to provide input to flow and transport models being developed for the Nopal I hydrogeologic system.

  12. Estimated seepage rates from selected ditches, ponds, and lakes at the Camas National Wildlife Refuge, eastern Idaho.

    PubMed

    Rattray, Gordon W

    2017-03-09

    The Camas National Wildlife Refuge (Refuge) in eastern Idaho, established in 1937, contains wetlands, ponds, and wet meadows that are essential resting and feeding habitat for migratory birds and nesting habitat for waterfowl. Initially, natural sources of water supported these habitats. However, during the past few decades, changes in climate and surrounding land use have altered and reduced natural groundwater and surface-water inflows, resulting in a 5-meter decline in the water table and an earlier, and more frequent, occurrence of no flow in Camas Creek at the Refuge. Due to these changes in water availability, water management that includes extensive groundwater pumping is now necessary to maintain the wetlands, ponds, and wet meadows. These water management activities have proven to be inefficient and expensive, and the Refuge is seeking alternative water-management options that are more efficient and less expensive. More efficient water management at the Refuge may be possible through knowledge of the seepage rates from ditches, ponds, and lakes at the Refuge. With this knowledge, water-management efficiency may be improved by natural means through selective use of water bodies with the smallest seepage rates or through engineering efforts to minimize seepage losses from water bodies with the largest seepage rates. The U.S. Geological Survey performed field studies in 2015 and 2016 to estimate seepage rates for selected ditches, ponds, and lakes at the Refuge. Estimated seepage rates from ponds and lakes ranged over an order of magnitude, from 3.4 ± 0.2 to 103.0 ± 0.5 mm/d, with larger seepage rates calculated for Big Pond and Redhead Pond, intermediate seepage rates calculated for Two-way Pond, and smaller seepages rates calculated for the south arm of Sandhole Lake. Estimated seepage losses from two reaches of Main Diversion Ditch were 21 ± 2 and 17 ± 2 percent/km. These losses represent seepage rates of about 890 and 860 mm/d, which are one

  13. H-Area Seepage Basins groundwater monitoring report. Second quarter 1992

    SciTech Connect

    Not Available

    1992-09-01

    During second quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Plant. This report gives the results of the analyses of groundwater from the H-Area Seepage Basin.

  14. Lagoon Seepage Testing Report for Central Facilities Area (CFA) Sewage Lagoons at Idaho National Laboratory, Butte County, Idaho

    SciTech Connect

    Morrison, Bridger

    2014-09-01

    J-U-B ENGINEERS, Inc. (J-U-B) performed seepage tests on the CFA Wastewater Lagoons 1, 2, and 3 between August 26th and September 22nd, 2014. The lagoons were tested to satisfy the Idaho Department of Environmental Quality (DEQ) Rules (IDAPA 58.01.16) that require all lagoons be tested at a frequency of every 10 years and the Compliance Activity CA-141-03 in the DEQ Wastewater Reuse Permit for the CFA Sewage Treatment Plant (LA-000141-03). The lagoons were tested to determine if the average seepage rates are less than 0.25 in/day, the maximum seepage rate allowed for lagoons built prior to April 15, 2007. The average seepage rates were estimated for each lagoon and are given in Table-ES1. The average seepage rates for Lagoons 1 and 2 are less than the allowable seepage rate of 0.25 in/day. Lagoon 1 and 2 passed the seepage test and will not have to be tested again until the year 20241. However, the average seepage rate for Lagoon 3 appears to exceed the allowable seepage rate of 0.25 in/day which means the potential source for the excessive leakage should be investigated further.

  15. H-Area Seepage Basins groundwater monitoring report

    SciTech Connect

    Thompson, C.Y.

    1992-06-01

    During first quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, antimony, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Site. This report presents and discusses the groundwater monitoring results in the H-Area for first quarter 1992.

  16. Impact of quaternary climate on seepage at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Whelan, J.F.; Paces, J.B.; Neymark, L.A.; Schmitt, A.K.; Grove, M.

    2006-01-01

    Uranium-series ages, oxygen-isotopic compositions, and uranium contents were determined in outer growth layers of opal and calcitefrom 0.5- to 3-centimeter-thick mineral coatings hosted by lithophysal cavities in the unsaturated zone at Yucca Mountain, Nevada, the proposed site of a permanent repository for high-level radioactive waste. Micrometer-scale growth layering in the minerals was imaged using a cathodoluminescence detector on a scanning electron microscope. Determinations of the chemistry, ages, and delta oxygen-18 (??18O) values of the growth layers were conducted by electron microprobe analysis and secondary ion mass spectrometry techniques at spatial resolutions of 2 to about 20 micrometers (??m) and 25 to 40 ??m, respectively. Growth rates for the last 300 thousand years (k.y.) calculated from about 300 new high-resolution uranium-series ages range from approximately 0.5 to 1.5 ??m/k.y. for 1- to 3-centimeter-thick coatings, whereas coatings less than about 1-centimeter-thick have growth rates less than 0.5 ??m/k.y. At the depth of the proposed repository, correlations of uranium concentration and ??18O values with regional climate records indicate that unsaturated zone percolation and seepage water chemistries have responded to changes in climate during the last several hundred thousand years.

  17. Impact of Quaternary Climate on Seepage at Yucca Mountain, Nevada

    SciTech Connect

    J.F. Whelan; J.B. Paces; L.A. Neymark; A.K. Schmitt; M. Grove

    2006-03-17

    Uranium-series ages, oxygen-isotopic compositions, and uranium contents were determined in outer growth layers of opal and calcite from 0.5- to 3-centimeter-thick mineral coatings hosted by lithophysal cavities in the unsaturated zone at Yucca Mountain, Nevada, the proposed site of a permanent repository for high-level radioactive waste. Micrometer-scale growth layering in the minerals was imaged using a cathodoluminescence detector on a scanning electron microscope. Determinations of the chemistry, ages, and delta oxygen-18 values of the growth layers were conducted by electron microprobe analysis and secondary ion mass spectrometry techniques at spatial resolutions of 1 to about 20 micrometers ({micro}m) and 25 to 40 micrometers, respectively. Growth rates for the last 300 thousand years (k.y.) calculated from about 300 new high-resolution uranium-series ages range from approximately 0.5 to 1.5 {micro}m/k.y. for 1- to 3-centimeter-thick coatings, whereas coatings less than about I-centimeter-thick have growth rates less than 0.5 {micro}m/k.y. At the depth of the proposed repository, correlations of uranium concentration and delta oxygen-18 values with regional climate records indicate that unsaturated zone percolation and seepage water chemistries have responded to changes in climate during the last several hundred thousand years.

  18. Effects of recharge, Upper Floridan aquifer heads, and time scale on simulated ground-water exchange with Lake Starr, a seepage lake in central Florida

    USGS Publications Warehouse

    Swancar, Amy; Lee, Terrie Mackin

    2003-01-01

    Lake Starr and other lakes in the mantled karst terrain of Florida's Central Lake District are surrounded by a conductive surficial aquifer system that receives highly variable recharge from rainfall. In addition, downward leakage from these lakes varies as heads in the underlying Upper Floridan aquifer change seasonally and with pumpage. A saturated three-dimensional finite-difference ground-water flow model was used to simulate the effects of recharge, Upper Floridan aquifer heads, and model time scale on ground-water exchange with Lake Starr. The lake was simulated as an active part of the model using high hydraulic conductivity cells. Simulated ground-water flow was compared to net ground-water flow estimated from a rigorously derived water budget for the 2-year period August 1996-July 1998. Calibrating saturated ground-water flow models with monthly stress periods to a monthly lake water budget will result in underpredicting gross inflow to, and leakage from, ridge lakes in Florida. Underprediction of ground-water inflow occurs because recharge stresses and ground-water flow responses during rainy periods are averaged over too long a time period using monthly stress periods. When inflow is underestimated during calibration, leakage also is underestimated because inflow and leakage are correlated if lake stage is maintained over the long term. Underpredicted leakage reduces the implied effect of ground-water withdrawals from the Upper Floridan aquifer on the lake. Calibrating the weekly simulation required accounting for transient responses in the water table near the lake that generated the greater range of net ground-water flow values seen in the weekly water budget. Calibrating to the weekly lake water budget also required increasing the value of annual recharge in the nearshore region well above the initial estimate of 35 percent of the rainfall, and increasing the hydraulic conductivity of the deposits around and beneath the lake. To simulate the total

  19. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    P. Dixon

    2004-04-05

    The purpose of this Model Report (REV02) is to document the unsaturated zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrological-chemical (THC) processes on UZ flow and transport. This Model Report has been developed in accordance with the ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (Bechtel SAIC Company, LLC (BSC) 2002 [160819]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this Model Report in Section 1.12, Work Package AUZM08, ''Coupled Effects on Flow and Seepage''. The plan for validation of the models documented in this Model Report is given in Attachment I, Model Validation Plans, Section I-3-4, of the TWP. Except for variations in acceptance criteria (Section 4.2), there were no deviations from this TWP. This report was developed in accordance with AP-SIII.10Q, ''Models''. This Model Report documents the THC Seepage Model and the Drift Scale Test (DST) THC Model. The THC Seepage Model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral alteration on flow in rocks surrounding drifts. The DST THC model is a drift-scale process model relying on the same conceptual model and much of the same input data (i.e., physical, hydrological, thermodynamic, and kinetic) as the THC Seepage Model. The DST THC Model is the primary method for validating the THC Seepage Model. The DST THC Model compares predicted water and gas compositions, as well as mineral alteration patterns, with observed data from the DST. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal-loading conditions, and predict the evolution of mineral alteration and fluid chemistry around potential waste emplacement drifts. The DST THC Model is used solely for the validation of the THC

  20. Seepage study of six canals in Salt Lake County, Utah, 1982-1983

    USGS Publications Warehouse

    Herbert, L.R.; Cruff, R.W.; Waddell, K.M.

    1985-01-01

    A study of selected reaches of the Utah and Salt Lake, Utah Lake Distributing, Provo Reservoir, Draper Irrigation, East Jordan, and Jordan and Salt Lake City Canals in Salt Lake County, Utah, was made to determine gains or losses of flow in those reaches. Three to five sets of seepage measurements were made on each canal during 1982 or 1983. Adjustments for fluctuations in flow were made from information obtained from water-stage recorders operated at selected locations during the time of each seepage run.The study showed an overall net loss of about 9.5 cubic feet per second in the Utah and Salt Lake Canal, 11.0 cubic feet per second in the Utah Lake Distributing canal, 20.5 cubic feet per second in the Provo Reservoir canal, 1.5 cubic feet per second in the Draper Irrigation Canal, and 4.0 cubic feet per second in the East Jordan canal. It also showed a net gain of about 6.0 cubic feet per second in the Jordan and Salt Lake City Canal. The gains and losses are attributed primarily to the relation of the canals to the depth of the water table near the canals.

  1. Field measurement of seepage and evapotranspiration rate for a soil under plant cover: A comparison of soil water balance and tritium labeling procedure

    NASA Astrophysics Data System (ADS)

    Kreutzer, K.; Strebel, O.; Renger, M.

    1980-08-01

    Vertical water flux at 90 cm depth and evapotranspiration were measured in a loess Parabraunerde soil profile, under spring wheat and sugar beets, respectively, during a time period of nearly 21 months. Two field methods were compared: the HTO-tracer method (labeling soil water at a depth of 60 cm followed by core sampling) and the soil water balance method (measuring soil water suction and water content as a function of depth and time). Outside the vegetation season the results of the two methods agreed well, but not during the vegetation season. The reason is that the reference soil compartment, with its reference depth of 90 cm, lies within the root zone and the HTO-method does not correctly reflect the water flux through the roots and the water withdrawal by the roots from this reference compartment. It is shown, that after correcting the HTO-values for these root-activity-dependent effects, a good agreement between the two methods was found also during periods with root activity. Investigations with the HTO-method lead to inaccurate results if the reference depth or the median value of the tracer distribution lie within the zone of active roots.

  2. An Integrated Approach to Determine Ground-water Surface Water Flux in a Contaminated Aquifer-Wetland System at the Norman Landfill Research Site, Oklahoma

    NASA Astrophysics Data System (ADS)

    Mendoza-Sanchez, I.; Phanikumar, M.; McGuire, J. T.; Masoner, J.; Cozzarelli, I.

    2008-12-01

    An area of research in progress at the Norman Landfill Research Site in Oklahoma involves a small wetland that overlies a landfill leachate plume. The wetland-aquifer system actively exchanges contaminants and nutrients. These chemicals move from the wetland to the aquifer and vice versa depending on the ground- water/surface-water exchange rate and flow direction. The ground-water/surface-water flow has to be quantified in order to better understand the influence of contaminants and nutrients on the transport and fate of landfill leachates. Different types of data have been collected at the site over a period of ten years including isotopic composition of water samples, ion concentrations, water levels, evaporative and seepage fluxes and meteorological variables. After identifying key processes influencing the water exchange between the wetland and ground-water based on time series analysis, we used process-based modeling to determine the ground-water/surface-water flow rates in the system using an integrated water balance model. Other methods used to constrain processes and parameters in the study include: (a) ground-water inflow calculation with stable environmental isotopes mass balance (b) ground-water input to the wetland with solute mass balance, and (c) Darcy's flow calculation of ground-water/surface-water exchange based on measurements from a network of piezometers. Preliminary results show that it is possible to differentiate between regional and local ground-water influences, as well as precipitation and evapotranspiration contributions in the exchange behavior.

  3. Evaluation Of The Physical Stability, Ground Water Seepage Control, And Faunal Changes Associated With An AquaBlok® Sediment Cap

    EPA Science Inventory

    Active sediment caps are being considered for addressing contaminated sediment areas in surface-water bodies. A demonstration of an active cap designed to reduce advective transport of contaminants using AquaBlok® (active cap material) was initiated in a small study a...

  4. A calorimetric method to determine water activity

    NASA Astrophysics Data System (ADS)

    Björklund, Sebastian; Wadsö, Lars

    2011-11-01

    A calorimetric method to determine water activity covering the full range of the water activity scale is presented. A dry stream of nitrogen gas is passed either over the solution whose activity should be determined or left dry before it is saturated by bubbling through water in an isothermal calorimeter. The unknown activity is in principle determined by comparing the thermal power of vaporization related to the gas stream with unknown activity to that with zero activity. Except for three minor corrections (for pressure drop, non-perfect humidification, and evaporative cooling) the unknown water activity is calculated solely based on the water activity end-points zero and unity. Thus, there is no need for calibration with references with known water activities. The method has been evaluated at 30 °C by measuring the water activity of seven aqueous sodium chloride solutions ranging from 0.1 mol kg-1 to 3 mol kg-1 and seven saturated aqueous salt solutions (LiCl, MgCl2, NaBr, NaCl, KCl, KNO3, and K2SO4) with known water activities. The performance of the method was adequate over the complete water activity scale. At high water activities the performance was excellent, which is encouraging as many other methods used for water activity determination have limited performance at high water activities.

  5. Percolation testing at the F- and H-Area Seepage Basins. Final report

    SciTech Connect

    McHood, M.D.

    1993-10-18

    The design of the F- and H-Area Seepage Basin contaminated groundwater remediation system requires information from multiple well pump tests (Reference 1). Soil percolation rates are needed in order to support the multiple well pump test planning. The objective of this task was to determine characteristic percolation rates for soils in four select areas where infiltration galleries are proposed. These infiltration galleries will be temporary installations built on the ground surface and used to disposes of water from the multiple well pump tests. A procedure defining the specific work process for collecting percolation rate data is contained in Appendix 3. Results from these percolation tests will be used in the design of infiltration galleries for the disposal of well water extracted during the multiple well pump tests.

  6. Hydrogeochemistry of Maine seepage lakes and related groundwaters

    NASA Astrophysics Data System (ADS)

    Stauffer, Robert E.; Wittchen, Bruce D.

    1992-10-01

    Southeastern Maine contains numerous small seepage lakes (no perennial surface inflows or outflows), set in felsic, glacial deposits (eskers, pitted outwash, glacio-marine deltaic terraces) dating from the Wisconsin glacial retreat ca. 12 500 years B.P. The modern landscape is either forested or maintained as low blueberry heath by semi-annual mowing and burning. Although local precipitation is currently moderately acidic (volume-weighted pH ≈ 4.5), spring waters issuing from the glacial deposits are only weakly acidic (6.1 < pH < 7.0), and bicarbonate-buffered (120 to 300 mmol m -3) on account of tertiary weathering by dissolved CO 2. The order of mobility (denudation rate) for base cations (BC) is: Ca > Na > Mg > K, the same as for upland granitic terrane in the same region. Springwater composition is temporally stable but geographically variable. The most dilute springwaters drain blueberry barrens. Here, chemical weathering is limited by available acidity as evidenced by the relatively high final pHs (> 6.3) and low concentrations of strong oxy-anions (nitrate, sulfate) and dissolved inorganic carbon (DIC < 250 μM). Closely neighboring lakes often range widely in alkalinity, BC, and F, depending on their connection to the local groundwater system. Tracer analysis indicates seepage inflow is equal to 5-50 cm year -1 for typical regional seepage lakes, vs. higher rates (> 100 cm year -1) for groundwater discharge lakes. Approximately 88% of Si inputs to regional seepage lakes is retained in the sediments. Non-marine sulfate is lowest in groundwater discharge lakes containing the highest concentrations of BC and F, and featuring the shortest hydraulic residence times, suggesting that S retention in lake sediments is currently less efficient than in the adjoining terrestrial soils and vegetation.

  7. Preliminary assessment of tree mortality near F- and H-area seepage basins

    SciTech Connect

    Loehle, C; Gladden, J

    1988-01-28

    A preliminary assessment was conducted to evaluate factors that may have been responsible for the vegetation damage that has occurred in groundwater seeps downslope from the F- and H-area seepage basins. The factors that were considered included altered hydrology, toxicity from hazardous chemical constituents associated with seepage basin operation, and toxicity from non-hazardous constituents associated with basin operation. It was concluded that the observed damage was not likely to have resulted from altered hydrologic conditions or hazardous constituents associated with basin operation. Insufficient information is currently available to determine definitively which of the non-hazardous constituents, alone or in concert, were responsible for the observed vegetation damage. The most likely explanation, however, is that elevated Na, pH, and conductivity is outcropping seep water are responsible for tree mortality. All three of these factors will return to ambient levels over a period of several years when basin operation ceases. Faster remediation can be achieved using lime at the seep line.

  8. Use of Polyacrylamide to Reduce Seepage From Unlined Irrigation Canals: Initial Results From Small Scale Test Troughs

    NASA Astrophysics Data System (ADS)

    Susfalk, R. B.; Young, M. H.; Schmidt, M.; Epstein, B. J.; Goreham, J.; Swhihart, J.; Smith, D.

    2005-12-01

    Polyacrylamide (PAM) is a class of long-chain synthetic polymers that are used extensively in food packaging, paper manufacturing, wastewater treatment, and as a soil amendment to reduce erosion. Recent empirical evidence has shown that applying linear, anionic PAM seepage can also reduce seepage from unlined irrigation canals. A diverse set of experiments has been initiated to understand the efficacy of PAM usage in ditch environments. The experiments span multiple scales, from small-scale bench top and artificial furrow experiments, to larger engineered furrows and irrigation ditches. Our objective was to assess the effectiveness of different PAM application methods and concentrations on seepage reductions in small scale, artificial Test Troughs (TT). The TT consists of two 24 m long, 10 cm deep furrows formed from native ASTM C-33 sand. During water application, inflows, outflows, and seepage from under the furrows were continuously measured. PAM in either granular or partially hydrated form was applied at various rates. The results presented here cover one facet of the research program. The application of granular PAM to the TT reduced seepage from 49 L/min to less than 22 L/min, depending on treatment. A PAM application rate of 44 kg/(canal ha) reduced seepage by 69+/-9 percent, and was more effective than an application rate of 11 kg/(canal ha) that reduced seepage by 56+/-22 percent. Seepage reduction was calculated using flow rates between 400 and 600 elapsed minutes. Inclusion of later data (up to 1440 min) into seepage calculations was complicated by a reduction in seepage at the control trough caused either by a reduction in head or deposition of suspended sediment. We hypothesize that the PAM-sediment layer present in the treated trough exerted a greater control on seepage than sediment deposition alone. However, heavy suspended sediment loads associated with hydrologic events reduced seepage rates within both the control and treated troughs, somewhat

  9. Dense distributed temperature sensing to infer local seepage fluxes in coastal areas

    NASA Astrophysics Data System (ADS)

    Hilgersom, Koen; van de Giesen, Nick

    2014-05-01

    In many deltas, land surfaces are largely below sea level, and consequently suffering from saline groundwater seepage. This phenomenon affects the fresh water supply for, for example, agriculture and drinking water production. In many of those deltas, sea level rise and land subsidence enhance these problems. Depending on the geology, the seepage fluxes can occur both distributed and locally. Local seepage occurs through ancient channels that were filled with higher-conductive material at later times, but also works its way up via small vents through the soil. The latter is called boil seepage and usually is the most saline of the mentioned seepage types. Boils commonly appear in ditches and canals, since the pressure gradient is most of the time larger compared to the surrounding area. Although boils appear only as local point inflows, their high discharge and consequent salt flux can make them contribute for over 70% of the salt flux into lowland water systems (de Louw et al., 2010). Seepage measurement methods include the application of so-called seepage meters and tracers like temperature. Conventional methods using temperature differences between groundwater and surface water require drilling temperature sensors into the soil. Because the locations of boils are sensitive to disturbances of the soil, we measure the seepage flux by measuring a 3D temperature profile in the surface water above the boil instead. The seepage flux is inferred from a numerical surface water model that includes salt and temperature transport. Laboratory and field results show the onset of stratification because of the denser groundwater. In the winter situation, the temperature of the groundwater is relatively high, and double diffusive processes may play a role, mainly because there is negligible lateral flow most of the time, when the downstream pumping station is not active. Therefore, a model is set up that is well able to represent these double diffusive processes. References De

  10. Experimental study of bentonite-soil mixtures as anti-seepage materials of constructed wetlands.

    PubMed

    Chen, Jing; Li, Zifu; Zhao, Xin; Li, Haihan

    2011-01-01

    In this study, mixtures of different kinds of bentonite and soil were used and tested in order to find a cheap alternative to current anti-seepage materials for constructed wetlands. The anti-seepage layer of constructed wetlands was simulated in the experimental study and the permeability coefficient of the mixed materials was determined in order to evaluate the anti-seepage effect of mixtures. The main results are as follows: (i) The minimum mass ratio of bentonite to soil is 10%; (ii) Within a certain range, the more compact and higher the wet density is, then the better anti-seepage effect is (under the condition of certain moisture content). The permeability coefficient of the mixed materials exponentially increased with the increase of wet density; (iii) At the wet density of 1.83 g/cm(3), corresponding with the optimum compactness, the mixture of natural sodium bentonite produced in Wyoming, USA and soil from Cangzhou, Hebei province showed the best anti-seepage performance; (iv) The impermeability of the mixture with smaller particle sizes of bentonite was far better than that with the bigger particle sizes; (v) The hydration effect of bentonite changed the structure of the mixture materials into a special structure that is similar to that of pure bentonite. The particles of the mixture became expanded under SEM investigation and the mixture became more compact, which could have the same or similar effect as pure bentonite for anti-seepage.

  11. Seepage erosion mechanisms of bank collapse: three-dimensional seepage particle mobilization and undercutting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seepage flow initiates undercutting, similar to development and headward migration of internal gullies, by liquefaction of soil particles, followed by mass wasting of the bank. Although seepage erosion has three-dimensional characteristics, two-dimensional lysimeters have been used in previous resea...

  12. Natural Oil Seepages : Detection, Monitoring and Relationships with Submarine Morphologies

    NASA Astrophysics Data System (ADS)

    Dhont, D.; Jatiault, R.; Dubucq, D.; Longépé, N.; Nhunfat, B.; Lucas, M.

    2014-12-01

    Detection of hydrocarbon shows in marine areas is of primary importance for oil and gas exploration since they confirm hydrocarbon generation and prove the presence of an active petroleum system. The use of spaceborne Synthetic Aperture Radar (SAR) images serves as an ideal technology for the imaging of hydrocarbon seeps as it is cost effective, provides large ground coverage with continuous acquisitions and operates day and night and in all weather conditions. Here, we present results on the interpretation of radar images for seepage detection on the West African margin. Long-term monitoring of 150 SAR scenes during 20 years allowed the recognition of more than 1400 oil seepages. Seabed morphologies associated to oil leakage correspond to clusters of small sized pockmarks, 50 to 200 m in diameter, and high-reflectivity mounds. The correlation between the location of the impact point of the oil plume at the sea surface with the seabed features reveals that oceanic drift of the oil is less than 1000 m through a water column of 1800 m, with a rising speed of 10 cm/s. In order to address the question of the seeps lifetime, we set up a short-term monitoring through the acquisition of one radar scene every 12 hours during 10 days in a specific area recognized for active oil leaking. Our main observations are: (i) the number of detected seeps varies spatially and temporally, and (ii) oil seep dissipation is effective in less than 12 hours. The variation of the hydrostatic pressure in the water column associated to the oscillation of the tide has been firstly considered as a possible mechanism controlling the expulsion of oil at the seafloor in relation with the number of seeps detected on each image. However, the correlation between the regional mean wind field and the amount of oil seeps strongly suggests that the wind is a primary factor to be considered for seepage detection. In addition, the age of the seepage on the sea surface is undetermined when the SAR imagery

  13. Characterization of seepage in the exploratory studies facility, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Oliver, T.A.; Whelan, J.F.

    2006-01-01

    Following a 5-month period of above-average precipitation during the winter of 2004-2005, water was observed seeping into the South Ramp section of the Exploratory Studies Facility of the proposed repository for high-level radioactive waste at Yucca Mountain, Nevada. Samples of the seepage were collected and analyzed for major ions, trace metals, and delta deuterium and delta oxygen-18 values in an effort to characterize the water and assess the interaction of seepage with anthropogenic materials used in the construction of the proposed repository. As demonstrated by the changes in the chemistry of water dripping from a rock bolt, interaction of seepage with construction materials can alter solution chemistry and oxidation state.

  14. Results of a seepage investigation at Bear Creek Valley, Oak Ridge, Tennessee, January through September 1994

    SciTech Connect

    Robinson, J.A.; Johnson, G.C.

    1996-12-31

    A seepage investigation was conducted of 4,600 acres of Bear Creek Valley southwest of the Y-12 Plant, Oak Ridge, Tennessee, for the period of January through September 1994. The data was collected to help the Y-12 Environmental Restoration Program develop a better understanding of ground-water and surface-water interactions, recharge and discharge relations, and ground-water flow patterns. The project was divided into three phases: a reconnaissance and mapping of seeps, springs, and stream-measurement sites; a high base flow seepage investigation; and a low base flow seepage investigation. This report describes the results of the investigation. It includes a map showing measurement site locations and tables that list the coordinates for each site and measurements of discharge, pH, specific conductance, temperature, and dissolved oxygen.

  15. A seepage investigation of an area at and near Oak Ridge National Laboratory, Oak Ridge, Tennessee, March through August 1993

    USGS Publications Warehouse

    Johnson, G.C.

    1996-01-01

    A seepage investigation was conducted of an area surrounding the Oak Ridge National Laboratory from March through August 1993. The project was divided into three phases: a reconnaissance to inventory and map seeps, springs, and stream-measurement sites; a high base flow seepage investigation; and a low base flow seepage investigation. The reconnaissance consisted of following each tributary to its source to inventory each site where water was issuing from the ground. Stream- measurement sites were also located along stream reaches at 500-foot intervals. A total of 822 sites were identified. A global positioning system was used to locate 483 sites to within 3- to 5-meter accuracy. The high base flow seepage investigation was conducted from April 29 through May 3, 1993, and from May 7 through May 10, 1993. During the high base flow seepage investigation, sites identified during the reconnaissance were revisited. At almost all sites with flowing water, discharge, pH, specific conductance, and temperature were recorded. Two hundred and fourteen sites were dry. The low base flow seepage investigation was conducted from August 8 through August 10, 1993, and consisted of revisiting the seeps and springs that were flowing during the high base flow seepage investigation. Stream- measurement sites were not revisited. One hundred and forty-one sites were dry.

  16. Groundwater seepage controls salinity in a hydrologically terminal basin of semi-arid northwest Australia

    NASA Astrophysics Data System (ADS)

    Skrzypek, Grzegorz; Dogramaci, Shawan; Rouillard, Alexandra; Grierson, Pauline F.

    2016-11-01

    Very small groundwater outflows have the potential to significantly impact the hydrochemistry and salt accumulation processes of notionally terminal basins in arid environments. However, this limited groundwater outflow can be very difficult to quantify using classical water budget calculations due to large uncertainties in estimates of evaporation and evapotranspiration rates from the surface of dry lake beds. In this study, we used a dimensionless time evaporation model to estimate the range of groundwater outflow required to maintain salinity levels observed at the Fortescue Marsh (FM), one of the largest wetlands of semi-arid northwest Australia (∼1100 km2). The groundwater outflow from aquifers underlying the FM to the Lower Fortescue catchment is constrained by an extremely low hydraulic gradient of <0.0001 and a small 'alluvial outlet' of 0.35 km2 because of relatively high bedrock elevation. However, FM groundwater salinity is far below saturation with respect to halite (TDS < 160 g/L), episodic flood water is fresh to brackish, and salt efflorescences are very sparse and evident only when the FM is dry. We show that if the FM was 100% ;leakage free; i.e., a true terminal basin, groundwater would have achieved halite saturation (>300 g/L) after ∼45 ka. We calculated that only a very small seepage of ∼2G L/yr (∼0.03% of the FM water volume) is sufficient to maintain current salinity conditions. The minimum time required to develop the current hydrochemical groundwater composition under the FM ranges from ∼60 to ∼165 ka. We conclude that a dimensionless time evaporation model versus inflow over outflow ratio model is likely more suitable than classical water budget calculations for determining outflow from large saline lakes and to estimate groundwater seepage from hydrologically terminal basins.

  17. Seepage study of the Sevier Valley-Piute Canal, Sevier County, Utah

    USGS Publications Warehouse

    Cruff, R.W.

    1977-01-01

    A study of the gains or losses of the Sevier Valley-Piute Canal from near Joseph to near Aurora, Sevier County, Utah, was made to aid in water allocation for the canal system. Four sets of seepage measurements were made in 1976, with the three most representative being used in the analysis. Adjustments for fluctuations in flow in the canals were made from information obtained from water-stage recorders operated at selected locations along the canal during the time of each seepage run.

  18. Estimation of past seepage volumes from calcite distribution in the Topopah Spring Tuff, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Marshall, B.D.; Neymark, L.A.; Peterman, Z.E.

    2003-01-01

    Low-temperature calcite and opal record the past seepage of water into open fractures and lithophysal cavities in the unsaturated zone at Yucca Mountain, Nevada, site of a proposed high-level radioactive waste repository. Systematic measurements of calcite and opal coatings in the Exploratory Studies Facility (ESF) tunnel at the proposed repository horizon are used to estimate the volume of calcite at each site of calcite and/or opal deposition. By estimating the volume of water required to precipitate the measured volumes of calcite in the unsaturated zone, seepage rates of 0.005 to 5 liters/year (l/year) are calculated at the median and 95th percentile of the measured volumes, respectively. These seepage rates are at the low end of the range of seepage rates from recent performance assessment (PA) calculations, confirming the conservative nature of the performance assessment. However, the distribution of the calcite and opal coatings indicate that a much larger fraction of the potential waste packages would be contacted by this seepage than is calculated in the performance assessment.

  19. A Tube Seepage Meter for In Situ Measurement of Seepage Rate and Groundwater Sampling.

    PubMed

    Solder, John E; Gilmore, Troy E; Genereux, David P; Solomon, D Kip

    2016-07-01

    We designed and evaluated a "tube seepage meter" for point measurements of vertical seepage rates (q), collecting groundwater samples, and estimating vertical hydraulic conductivity (K) in streambeds. Laboratory testing in artificial streambeds show that seepage rates from the tube seepage meter agreed well with expected values. Results of field testing of the tube seepage meter in a sandy-bottom stream with a mean seepage rate of about 0.5 m/day agreed well with Darcian estimates (vertical hydraulic conductivity times head gradient) when averaged over multiple measurements. The uncertainties in q and K were evaluated with a Monte Carlo method and are typically 20% and 60%, respectively, for field data, and depend on the magnitude of the hydraulic gradient and the uncertainty in head measurements. The primary advantages of the tube seepage meter are its small footprint, concurrent and colocated assessments of q and K, and that it can also be configured as a self-purging groundwater-sampling device.

  20. Quantitative determination of engine water ingestion

    NASA Technical Reports Server (NTRS)

    Parikh, P.; Hernan, M.; Sarohia, V.

    1986-01-01

    This paper describes a novel non-intrusive optical technique for determination of liquid mass flux in a droplet laden airstream. The technique was developed for quantitative determination of engine water ingestion resulting from heavy rain or wheel spray. Independent measurements of the liquid water content (LWC) of the droplet laden aircraft and of the droplet velocities were made at the simulated nacelle inlet plane for the liquid mass flux determination. The liquid water content was measured by illuminating and photographing the droplets contained within a thin slice of the flow field by means of a sheet of light from a pulsed YAG laser. A fluorescent dye introduced in the water greatly improved the droplet image definition. The droplet velocities were determined from double exposed photographs of the moving droplet field. The technique was initially applied to a steady spray generated in a wind tunnel. It was found that although the spray was initially steady, the aerodynamic breakup process was inherently unsteady. This resulted in a wide variation of the instantaneous liquid water content of the droplet laden airstream. The standard deviation of ten separate LWC measurements was 31 percent of the average. However, the liquid mass flux calculated from the average LWC and droplet velocities came within 10 percent of the known water ingestion rate.

  1. Turbulent flow statistics of vegetative channel with seepage

    NASA Astrophysics Data System (ADS)

    Devi, Thokchom Bebina; Kumar, Bimlesh

    2015-12-01

    The present study is carried out for studying the impact of submerged, flexible vegetation in a channel where downward seepage occurs. Laboratory experiments on artificial vegetation of two different heights, 8 cm and 6 cm, were conducted for no-seepage, 10% seepage and 15% seepage cases. Vegetation height is an important parameter in influencing the flow characteristics in a vegetated channel, where velocity is reduced near the top of the vegetation. Results show that velocity measured at upstream vegetation section is always higher than the downstream section even with the application of downward seepage. The maximum value of Reynolds stress occurs near the top of the vegetation. When the flow enters the vegetation section, the local effect of the presence of vegetation on sediment transport is more at the upstream vegetation section and then decreases which is shown by higher Reynolds stress at the upstream as compared to downstream vegetation section highlighting the importance of vegetation in providing as an erosion control. The maximum Reynolds stress at no seepage is increased by a percentage of 17% for 10% seepage and average of 30.5% for 15% seepage. The turbulence intensities at no seepage are increased by an average value of 15% for 10% seepage and 25% for 15% seepage. The reduction of Reynolds stress and turbulent intensities along the longitudinal direction implies the importance of using vegetation as a river restoration measure providing considerable stability to channels. Third order moments highlight that downward seepage increases the streamwise flux and decreases the upward flux.

  2. Transient hydrogeological controls on the chemistry of a seepage lake

    USGS Publications Warehouse

    Krabbenhoft, David P.; Webster, Katherine E.

    1995-01-01

    A solute mass balance method was used to estimate groundwater inflow and outflow rates for Nevins Lake, Michigan, a seepage lake in the upper peninsula that historically has shown extremely variable water chemistry compared with most other seepage lakes. A 4-year study (1989–1992) of the hydrology and geochemistry of Nevins Lake and its contiguous groundwater system revealed that changes in the mass of dissolved solutes are the result of annual hydraulic gradient reversals. A pronounced acidification of Nevins Lake from 1986 to 1988 was likely caused by drought-induced diminished groundwater inflow rates. In this study, dissolved calcium (the major cation in water of Nevins Lake, groundwater, and precipitation) was used for estimating mass flow rates. During the 1989–1992 period, Nevins Lake showed a reproducible annual cycle in calcium mass. Immediately following spring snowmelt and the resulting hydraulic gradient reversal, the mass of dissolved calcium in the lake increases rapidly, and then it decreases steadily throughout the summer and early fall, at which time the lake becomes hydraulically mounded and receives no groundwater inflow. Groundwater flow rates estimated by the solute mass balance method are sensitive to assumed solute concentrations in discharging groundwater. Pore water samples from the lake bed are shown to be more representative of water discharging to the lake than are samples from piezometers near the lake shore, but spatial and temporal variability in pore water chemistry must be considered. Stable isotope analyses (18O and 2H) of lake water, groundwater, and pore water samples show that water discharging to Nevins Lake in the spring is entirely recycled lake water, and no groundwater derived from terrestrial recharge reaches the lake. The conceptual model formulated during this study linking lake chemistry and the contiguous groundwater system and general groundwater flow patterns surrounding highly transient lake systems are likely

  3. Potential for seepage erosion of landslide dam

    USGS Publications Warehouse

    Meyer, W.; Schuster, R.L.; Sabol, M.A.

    1994-01-01

    The failure potential of the debris-avalanche dam at Castle Lake near Mount St. Helens, Washington, by three processes of seepage erosion (1) Heave; (2) piping; and (3) internal erosion, is examined. Results indicated that the dam is stable against piping but potentially locally unstable against heave. -from Authors

  4. Seepage study for unnamed tributary to Alder Creek, Stevens County, Washington

    USGS Publications Warehouse

    Carpenter, P.J.; Drost, B.W.

    1979-01-01

    Analysis of seepage measurements in the Alder Creek basin, Stevens County, Wash., shows that approximately 50% of 0.2 cubic foot per second taken from an unnamed tributary and used for the 1978 irrigation season would have reached Alder Creek as surface flow. Differences in discharge and specific conductance are explained by the basin geology, physical characteristics, climate, and water use. Only general conclusions could be made from data collected for five seepage measurements because irrigation activities could not be scheduled to allow the hydrologic system to reach equilibrium. (USGS)

  5. Drift-Scale Coupled Processes (DST and TH Seepage) Models

    SciTech Connect

    J. Birkholzer; S. Mukhopadhyay

    2004-09-29

    The purpose of this report is to document drift-scale modeling work performed to evaluate the thermal-hydrological (TH) behavior in Yucca Mountain fractured rock close to waste emplacement drifts. The heat generated by the decay of radioactive waste results in rock temperatures elevated from ambient for thousands of years after emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling conditions in the rock, giving rise to water redistribution and altered flow paths. The predictive simulations described in this report are intended to investigate fluid flow in the vicinity of an emplacement drift for a range of thermal loads. Understanding the TH coupled processes is important for the performance of the repository because the thermally driven water saturation changes affect the potential seepage of water into waste emplacement drifts. Seepage of water is important because if enough water gets into the emplacement drifts and comes into contact with any exposed radionuclides, it may then be possible for the radionuclides to be transported out of the drifts and to the groundwater below the drifts. For above-boiling rock temperatures, vaporization of percolating water in the fractured rock overlying the repository can provide an important barrier capability that greatly reduces (and possibly eliminates) the potential of water seeping into the emplacement drifts. In addition to this thermal process, water is inhibited from entering the drift opening by capillary forces, which occur under both ambient and thermal conditions (capillary barrier). The combined barrier capability of vaporization processes and capillary forces in the near-field rock during the thermal period of the repository is analyzed and discussed in this report.

  6. DRIFT-SCALE COUPLED PROCESSES (DST AND TH SEEPAGE) MODELS

    SciTech Connect

    J.T. Birkholzer; S. Mukhopadhyay

    2005-01-13

    The purpose of this report is to document drift-scale modeling work performed to evaluate the thermal-hydrological (TH) behavior in Yucca Mountain fractured rock close to waste emplacement drifts. The heat generated by the decay of radioactive waste results in rock temperatures elevated from ambient for thousands of years after emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling conditions in the rock, giving rise to water redistribution and altered flow paths. The predictive simulations described in this report are intended to investigate fluid flow in the vicinity of an emplacement drift for a range of thermal loads. Understanding the TH coupled processes is important for the performance of the repository because the thermally driven water saturation changes affect the potential seepage of water into waste emplacement drifts. Seepage of water is important because if enough water gets into the emplacement drifts and comes into contact with any exposed radionuclides, it may then be possible for the radionuclides to be transported out of the drifts and to the groundwater below the drifts. For above-boiling rock temperatures, vaporization of percolating water in the fractured rock overlying the repository can provide an important barrier capability that greatly reduces (and possibly eliminates) the potential of water seeping into the emplacement drifts. In addition to this thermal process, water is inhibited from entering the drift opening by capillary forces, which occur under both ambient and thermal conditions (capillary barrier). The combined barrier capability of vaporization processes and capillary forces in the near-field rock during the thermal period of the repository is analyzed and discussed in this report.

  7. The need to consider temporal variability when modelling exchange at the sediment-water interface

    USGS Publications Warehouse

    Rosenberry, Donald O.

    2011-01-01

    Most conceptual or numerical models of flows and processes at the sediment-water interface assume steady-state conditions and do not consider temporal variability. The steady-state assumption is required because temporal variability, if quantified at all, is usually determined on a seasonal or inter-annual scale. In order to design models that can incorporate finer-scale temporal resolution we first need to measure variability at a finer scale. Automated seepage meters that can measure flow across the sediment-water interface with temporal resolution of seconds to minutes were used in a variety of settings to characterize seepage response to rainfall, wind, and evapotranspiration. Results indicate that instantaneous seepage fluxes can be much larger than values commonly reported in the literature, although seepage does not always respond to hydrological processes. Additional study is needed to understand the reasons for the wide range and types of responses to these hydrologic and atmospheric events.

  8. Vertical migration of fine-grained sediments from interior to surface of seabed driven by seepage flows-`sub-bottom sediment pump action'

    NASA Astrophysics Data System (ADS)

    Zhang, Shaotong; Jia, Yonggang; Wen, Mingzheng; Wang, Zhenhao; Zhang, Yaqi; Zhu, Chaoqi; Li, Bowen; Liu, Xiaolei

    2017-02-01

    A scientific hypothesis is proposed and preliminarily verified in this paper: under the driving of seepage flows, there might be a vertical migration of fine-grained soil particles from interior to surface of seabed, which is defined as `sub-bottom sediment pump action' in this paper. Field experiments were performed twice on the intertidal flat of the Yellow River delta to study this process via both trapping the pumped materials and recording the pore pressures in the substrate. Experimental results are quite interesting as we did observe yellow slurry which is mainly composed of fine-grained soil particles appearing on the seabed surface; seepage gradients were also detected in the intertidal flat, under the action of tides and small wind waves. Preliminary conclusions are that `sediment pump' occurs when seepage force exceeds a certain threshold: firstly, it is big enough to disconnect the soil particles from the soil skeleton; secondly, the degree of seabed fluidization or bioturbation is big enough to provide preferred paths for the detached materials to migrate upwards. Then they would be firstly pumped from interior to the surface of seabed and then easily re-suspended into overlying water column. Influential factors of `sediment pump' are determined as hydrodynamics (wave energy), degree of consolidation, index of bioturbation (permeability) and content of fine-grained materials (sedimentary age). This new perspective of `sediment pump' may provide some implications for the mechanism interpretation of several unclear geological phenomena in the Yellow River delta area.

  9. Characterization of focused seepage through an earthfill dam using geoelectrical methods.

    PubMed

    Ikard, S J; Revil, A; Schmutz, M; Karaoulis, M; Jardani, A; Mooney, M

    2014-01-01

    Resistivity and self-potential tomography can be used to investigate anomalous seepage inside heterogeneous earthen dams. The self-potential (SP) signals provide a unique signature to groundwater flow because the source current density responsible for the SP signals is proportional to the Darcy velocity. The distribution of the SP signals is also influenced by the distribution of the resistivity; therefore, resistivity and SP need to be used in concert to elucidate groundwater flow pathways. In this study, a survey is conducted at a small earthen dam in Colorado where anomalous seepage is observed on the downstream face at the dam toe. The data reveal SP and direct current resistivity anomalies that are used to delineate three anomalous seepage zones within the dam and to estimate the source of the localized seepage discharge. The SP data are inverted in two dimensions using the resistivity distribution to determine the distribution of the Darcy velocity responsible for the observed seepage. The inverted Darcy velocity agrees with an estimation of the Darcy velocity from the hydraulic conductivity obtained from a slug test and the observed head gradient.

  10. A Field Exercise on Groundwater Flow Using Seepage Meters and Mini-Piezometers.

    ERIC Educational Resources Information Center

    Lee, David R.; Cherry, John A.

    1979-01-01

    Basic principles of physical hydrogeology and the nature of hydrologic interactions between groundwater and surface water can be demonstrated using two devices, the miniature piezometer and the seepage meter which can be cheaply constructed by the teacher and students. Use of the devices and learning activities are presented. (RE)

  11. Natural convection in tunnels at Yucca Mountain and impact on drift seepage

    SciTech Connect

    Halecky, N.; Birkholzer, J.T.; Peterson, P.

    2010-04-15

    The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock in the drift center to the drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water-induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.

  12. Influence of riparian seepage zones on nitrate variability in two agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian seepage zones are one of the primary pathways of groundwater transport to headwater streams. While seeps have been recognized for their contributions to streamflow, there is little information on how seeps affect stream water quality. The objective of this study was to examine the influence...

  13. Quantitative determination of engine water ingestion

    NASA Technical Reports Server (NTRS)

    Parikh, P.; Hernan, M.; Sarohia, V.

    1986-01-01

    A nonintrusive optical technique is described for determination of liquid mass flux in a droplet laden airstream. The techniques were developed for quantitative determination of engine water ingestion resulting from heavy rain or wheel spray. Independent measurements of the liquid water content (LWC) of the droplet laden airstream and of the droplet velocities were made at the stimulated nacelle inlet plane for the liquid mass flux determination. The LWC was measured by illuminating and photographing the droplets contained within a thin slice of the flow field by means of a sheet of light from a pulsed laser. A fluorescent dye introduced in the water enchanced the droplet image definition. The droplet velocities were determined from double exposed photographs of the moving droplet field. The technique was initially applied to a steady spray generated in a wind tunnel. It was found that although the spray was initially steady, the aerodynamic breakup process was inherently unsteady. This resulted in a wide variation of the instantaneous LWC of the droplet laden airstream. The standard deviation of ten separate LWC measurements was 31% of the average. However, the liquid mass flux calculated from the average LWC and droplet velocities came within 10% of the known water ingestion rate.

  14. A steady state solution for ditch drainage problem with special reference to seepage face and unsaturated zone flow contribution: Derivation of a new drainage spacing eqaution

    NASA Astrophysics Data System (ADS)

    Yousfi, Ammar; Mechergui, Mohammed

    2016-04-01

    al. (2001). In this work, a novel solution based on theoretical approach will be adapted to incorporate both the seepage face and the unsaturated zone flow contribution for solving ditch drained aquifers problems. This problem will be tackled on the basis of the approximate 2D solution given by Castro-Orgaz et al. (2012). This given solution yields the generalized water table profile function with a suitable boundary condition to be determined and provides a modified DF theory which permits as an outcome the analytical determination of the seepage face. To assess the ability of the developed equation for water-table estimations, the obtained results were compared with numerical solutions to the 2-D problem under different conditions. It is shown that results are in fair agreement and thus the resulting model can be used for designing ditch drainage systems. With respect to drainage design, the spacings calculated with the newly derived equation are compared with those computed from the DF theory. It is shown that the effect of the unsaturated zone flow contribution is limited to sandy soils and The calculated maximum increase in drain spacing is about 30%. Keywords: subsurface ditch drainage; unsaturated zone; seepage face; water-table, ditch spacing equation

  15. On leakage and seepage from geological carbon sequestration sites

    SciTech Connect

    Oldenburg, C.M.; Unger, A.J.A.; Hepple, R.P.; Jordan, P.D.

    2002-07-18

    Geologic carbon sequestration is one strategy for reducing the rate of increase of global atmospheric carbon dioxide (CO{sub 2} ) concentrations (IEA, 1997; Reichle, 2000). As used here, the term geologic carbon sequestration refers to the direct injection of supercritical CO{sub 2} deep into subsurface target formations. These target formations will typically be either depleted oil and gas reservoirs, or brine-filled permeable formations referred to here as brine formations. Injected CO{sub 2} will tend to be trapped by one or more of the following mechanisms: (1) permeability trapping, for example when buoyant supercritical CO{sub 2} rises until trapped by a confining caprock; (2) solubility trapping, for example when CO{sub 2} dissolves into the aqueous phase in water-saturated formations, or (3) mineralogic trapping, such as occurs when CO{sub 2} reacts to produce stable carbonate minerals. When CO{sub 2} is trapped in the subsurface by any of these mechanisms, it is effectively sequestered away from the atmosphere where it would otherwise act as a greenhouse gas. The purpose of this report is to summarize our work aimed at quantifying potential CO{sub 2} seepage due to leakage from geologic carbon sequestration sites. The approach we take is to present first the relevant properties of CO{sub 2} over the range of conditions from the deep subsurface to the vadose zone (Section 2), and then discuss conceptual models for how leakage might occur (Section 3). The discussion includes consideration of gas reservoir and natural gas storage analogs, along with some simple estimates of seepage based on assumed leakage rates. The conceptual model discussion provides the background for the modeling approach wherein we focus on simulating transport in the vadose zone, the last potential barrier to CO{sub 2} seepage (Section 4). Because of the potentially wide range of possible properties of actual future geologic sequestration sites, we carry out sensitivity analyses by

  16. GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY

    SciTech Connect

    Millings, M.; Denham, M.; Looney, B.

    2012-05-08

    From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors affecting basin

  17. H-Area Seepage Basins. Third quarter 1990 groundwater quality assessment report

    SciTech Connect

    Stejskal, G.

    1990-12-01

    During the third quarter of 1990 the wells which make up the H-Area Seepage Basins (H-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, nonvolatile beta, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, nonvolatile beta, trichloroethylene (TCE), tetrachloroethylene, lead, cadmium, arsenic, and total radium.

  18. H-Area Seepage Basin (H-HWMF): Fourth quarterly 1989, groundwater quality assessment report

    SciTech Connect

    Not Available

    1990-03-01

    During the fourth quarter of 1989 the wells which make up the H-Area Seepage Basins (H-HWMF){sup 1} monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, and total radium.

  19. Microbial community changes along the active seepage site of one cold seep in the Red Sea

    PubMed Central

    Cao, Huiluo; Zhang, Weipeng; Wang, Yong; Qian, Pei-Yuan

    2015-01-01

    The active seepage of the marine cold seeps could be a critical process for the exchange of energy between the submerged geosphere and the sea floor environment through organic-rich fluids, potentially even affecting surrounding microbial habitats. However, few studies have investigated the associated microbial community changes. In the present study, 16S rRNA genes were pyrosequenced to decipher changes in the microbial communities from the Thuwal seepage point in the Red Sea to nearby marine sediments in the brine pool, normal marine sediments and water, and benthic microbial mats. An unexpected number of reads from unclassified groups were detected in these habitats; however, the ecological functions of these groups remain unresolved. Furthermore, ammonia-oxidizing archaeal community structures were investigated using the ammonia monooxygenase subunit A (amoA) gene. Analysis of amoA showed that planktonic marine habitats, including seeps and marine water, hosted archaeal ammonia oxidizers that differed from those in microbial mats and marine sediments, suggesting modifications of the ammonia oxidizing archaeal (AOA) communities along the environmental gradient from active seepage sites to peripheral areas. Changes in the microbial community structure of AOA in different habitats (water vs. sediment) potentially correlated with changes in salinity and oxygen concentrations. Overall, the present results revealed for the first time unanticipated novel microbial groups and changes in the ammonia-oxidizing archaea in response to environmental gradients near the active seepages of a cold seep. PMID:26284035

  20. Microbial community changes along the active seepage site of one cold seep in the Red Sea.

    PubMed

    Cao, Huiluo; Zhang, Weipeng; Wang, Yong; Qian, Pei-Yuan

    2015-01-01

    The active seepage of the marine cold seeps could be a critical process for the exchange of energy between the submerged geosphere and the sea floor environment through organic-rich fluids, potentially even affecting surrounding microbial habitats. However, few studies have investigated the associated microbial community changes. In the present study, 16S rRNA genes were pyrosequenced to decipher changes in the microbial communities from the Thuwal seepage point in the Red Sea to nearby marine sediments in the brine pool, normal marine sediments and water, and benthic microbial mats. An unexpected number of reads from unclassified groups were detected in these habitats; however, the ecological functions of these groups remain unresolved. Furthermore, ammonia-oxidizing archaeal community structures were investigated using the ammonia monooxygenase subunit A (amoA) gene. Analysis of amoA showed that planktonic marine habitats, including seeps and marine water, hosted archaeal ammonia oxidizers that differed from those in microbial mats and marine sediments, suggesting modifications of the ammonia oxidizing archaeal (AOA) communities along the environmental gradient from active seepage sites to peripheral areas. Changes in the microbial community structure of AOA in different habitats (water vs. sediment) potentially correlated with changes in salinity and oxygen concentrations. Overall, the present results revealed for the first time unanticipated novel microbial groups and changes in the ammonia-oxidizing archaea in response to environmental gradients near the active seepages of a cold seep.

  1. Assessment of electrical resistivity method to map groundwater seepage zones in heterogeneous sediments

    USGS Publications Warehouse

    Gagliano, Michael P.; Nyquist, Jonathan E.; Toran, Laura; Rosenberry, Donald O.

    2009-01-01

    Underwater electrical‐resistivity data were collected along the southwest shore of Mirror Lake, NH, as part of a multi‐year assessment of the utility of geophysics for mapping groundwater seepage beneath lakes. We found that resistivity could locate shoreline sections where water is seeping out of the lake. A resistivity line along the lake bottom starting 27‐m off shore and continuing 27‐m on shore (1‐m electrode spacing) showed the water table dipping away from the lake, the gradient indicative of lake discharge in this area. Resistivity could also broadly delineate high‐seepage zones. An 80‐m line run parallel to shore using a 0.5‐m electrode spacing was compared with measurements collected the previous year using 1‐m electrode spacing. Both data sets showed the transition from high‐seepage glacial outwash, to low‐seepage glacial till, demonstrating reproducibility. However, even the finer 0.5‐m electrode spacing was insufficient to resolve the heterogeneity well enough to predict seepage variability within each zone. For example, over a 12.5‐m stretch where seepage varied from 1–38 cm/day, resistivity varied horizontally from 700–3900 ohm‐m and vertically in the top 2‐m from 900–4000 ohm‐m without apparent correlation with seepage. In two sections along this 80‐m line, one over glacial outwash, the other over till, we collected 14 parallel lines of resistivity, 13.5 m long spaced 1 m apart to form a 13.5 × 13 m data grid. These lines were inverted individually using a 2‐D inversion program and then interpolated to create a 3‐D volume. Examination of resistivity slices through this volume highlights the heterogeneity of both these materials, suggesting groundwater flow takes sinuous flow paths. In such heterogeneous materials the goal of predicting the precise location of high‐seepage points remains elusive.

  2. Seismic Stability of Subsea Tunnels Subjected to Seepage

    PubMed Central

    Cheng, Xuansheng; Ren, Yi; Du, Xiuli

    2014-01-01

    Strength reduction method and ADINA software are adopted to study the stability of submarine tunnel structures subjected to seepage and earthquake under different seawater depths and overlying rock strata thicknesses. First, the excess pore water pressure in the rock mass is eliminated through consolidation calculation. Second, dynamic time-history analysis is performed by inputting the seismic wave to obtain the maximum horizontal displacement at the model top. Finally, static analysis is conducted by inputting the gravity and the lateral border node horizontal displacement when the horizontal displacement is the largest on the top border. The safety factor of a subsea tunnel structure subjected to seepage and earthquake is obtained by continuously reducing the shear strength parameters until the calculation is not convergent. The results show that the plastic zone initially appears at a small scope on the arch feet close to the lining structure and at both sides of the vault. Moreover, the safety factor decreases with increasing seawater depth and overlying rock strata thickness. With increasing seawater depth and overlying rock strata thickness, maximum main stress, effective stress, and maximum displacement increase, whereas displacement amplitude slightly decreases. PMID:24778591

  3. Seismic stability of subsea tunnels subjected to seepage.

    PubMed

    Cheng, Xuansheng; Ren, Yi; Du, Xiuli; Zhang, Yida

    2014-01-01

    Strength reduction method and ADINA software are adopted to study the stability of submarine tunnel structures subjected to seepage and earthquake under different seawater depths and overlying rock strata thicknesses. First, the excess pore water pressure in the rock mass is eliminated through consolidation calculation. Second, dynamic time-history analysis is performed by inputting the seismic wave to obtain the maximum horizontal displacement at the model top. Finally, static analysis is conducted by inputting the gravity and the lateral border node horizontal displacement when the horizontal displacement is the largest on the top border. The safety factor of a subsea tunnel structure subjected to seepage and earthquake is obtained by continuously reducing the shear strength parameters until the calculation is not convergent. The results show that the plastic zone initially appears at a small scope on the arch feet close to the lining structure and at both sides of the vault. Moreover, the safety factor decreases with increasing seawater depth and overlying rock strata thickness. With increasing seawater depth and overlying rock strata thickness, maximum main stress, effective stress, and maximum displacement increase, whereas displacement amplitude slightly decreases.

  4. The origin of elevated water levels in emplacement boreholes, Pahute Mesa, Nevada Test Site: A numerical study

    SciTech Connect

    Gardner, G.G.; Brikowski, T.H.

    1993-12-01

    The origin of elevated water levels in emplacement boreholes at Pahute Mesa, Nevada Test Site, is uncertain. If the water is from naturally perched aquifers, then presumed ``above water table`` weapons tests may directly impact the groundwater quality. The purpose of this study is to determine the probable source of the elevated water in boreholes by comparing modeled seepage of infiltrated drilling fluids, and the seepage from a simulated naturally perched aquifer with the observed water level history. In the model, large volumes of water are infiltrated, yet return flow of fluids back into the hole stops within three days after the end of drilling and is insufficient to produce observed standing water. Return flow is limited for two reasons: (1) the volume of the saturated rock next to the borehole is small; (2) pressure head gradient direct unsaturated flow away from the borehole. Simulation of seepage from a naturally perched aquifer readily reproduces the observed water levels.

  5. The impact of oil seepages and municipal wastewaters on Tembi River sediments, Masjedsoleyman (SW Iran)

    NASA Astrophysics Data System (ADS)

    Bavarsad, Zeynab; Moore, Farid; Modaberi, Soroush; Hessam, Alireza

    2010-05-01

    Oil seepage in Masjedsoleyman oil-producing region and urban and industrial effluents discharge into the main stream of Masjedsoleyman and eventually into Tembi River has polluted this river. The water of Masjedsoleyman main stream is used for livestock drinking and Tembi River is famous as a tourist site and camping. In this study, ten sampling stations were chosen along the main stream of Masjed¬soleyman and Tembi River. Heavy metal concentrations (Zn, Ni, Cu, Cd, Co, Cr, Pb, Fe), carbonate content, texture, pH, total petroleum hydrocarbon (TPH), total organic carbon (TOC) and free hydrocarbon(S1) in sediments samples were analyzed using ICP-MS, GC-MS and Rockeval 6. In order to determine the most important transporting phase in the sediment, Tessier sequential extraction is used. Correlation between metals and petroleum hydrocarbon and physical properties of sediment, probable source and spread of pollution are discussed. The concentration of contaminants is compared with threshold effect concentration (TEC) and probable effect concentration (PEC). Contamination factor (CF) has been calculated to assess the degree of pollution in sediments. Enrichment factors illustrate maximum enrichment of metals in sediments of Dare Khersan of Masjedsoleyman stream. Sequential extraction analysis shows iron, chrome, copper and zinc accumulate mainly in residual phase. In the majority of sediment Pb occurs in the organic fraction. Cd in sediments appears mainly in the exchangeable fraction, followed by the Fe-Mn oxides and residual fractions. The bioavailability of heavy metals decrease as Cd> Ni> Co> Pb> Cr> Zn> Cu> Fe. This study shows that the major source of heavy metals is the discharge of municipal sewage but the source of Ni is the oil seepages. Comparing the heavy metal concentrations with the consensus-based TEC and PEC values revealed that some metals such as Cd, Cr, Ni and Zn in some sediment samples are higher than both TEC and PEC, values

  6. Inertial (non-Darcian) channeled seepage flow

    NASA Astrophysics Data System (ADS)

    Foda, Mostafa A.

    1994-10-01

    A slow wave solution is identified for an infinite elastic medium intersected by a two-dimensional fluid channel. Because the wave speed is much slower than the medium's elastic shear wave, the response in the elastic medium is governed by elastostatics. The inertia of the wave is essentially focused in the fluid channel. Furthermore, wave damping is caused by fluid viscous friction on the channel in an elastic solid. It is proposed that these solutions may also be used in the case of a granular porous medium. The seepage channels would then represent a network of preferential flow paths. Therefore we would allow, in this case, the channel porosity to be different from the average granular porosity. For a strongly channel seepage flow or for a low channel porosity the solution is shown to approach that of a single-channel solution, giving rise to a slow propagating wave mode. On the other hand, for weak channeling or nearly `homogeneous' seepage flow the solution is shown to reproduce Biot's (1956) critically damped wave of the second kind. It is proposed that the resonance observed by Foda and Tzang (1994) are in the form of these strongly channeled wave modes.

  7. Seepage Bifurcation as a Critical Process

    NASA Astrophysics Data System (ADS)

    Yi, R.; Rothman, D.

    2015-12-01

    Channel networks form beautiful and surprisingly intricate geometries, yet diligently evade comprehensive mathematical understanding. Work in recent years has shed light on this problem. Networks driven by seepage flow, in particular, have been shown to grow in a field that can be described by the Laplace equation, providing us with an understanding of valley growth and shape. However, the process by which such networks branch to form these ramified shapes is yet a mystery. We focus our attention on a highly ramified seepage valley network in Bristol, Florida. We study the behavior of flux to valley heads as a function of valley length, and use this result to motivate our discussion of branch formation. We then hypothesize that a critical groundwater flux demarcates a transition point where topographic diffusion is overcome by branching processes, and we present network-wide flux calculations, cosmogenic data, and simulation to support our claim. Our results ultimately suggest a mechanism for seepage bifurcation, and inform our understanding of pattern formation in river networks.

  8. Evaluation of seepage and discharge uncertainty in the middle Snake River, southwestern Idaho

    USGS Publications Warehouse

    Wood, Molly S.; Williams, Marshall L.; Evetts, David M.; Vidmar, Peter J.

    2014-01-01

    The U.S. Geological Survey, in cooperation with the State of Idaho, Idaho Power Company, and the Idaho Department of Water Resources, evaluated seasonal seepage gains and losses in selected reaches of the middle Snake River, Idaho, during November 2012 and July 2013, and uncertainty in measured and computed discharge at four Idaho Power Company streamgages. Results from this investigation will be used by resource managers in developing a protocol to calculate and report Adjusted Average Daily Flow at the Idaho Power Company streamgage on the Snake River below Swan Falls Dam, near Murphy, Idaho, which is the measurement point for distributing water to owners of hydropower and minimum flow water rights in the middle Snake River. The evaluated reaches of the Snake River were from King Hill to Murphy, Idaho, for the seepage studies and downstream of Lower Salmon Falls Dam to Murphy, Idaho, for evaluations of discharge uncertainty. Computed seepage was greater than cumulative measurement uncertainty for subreaches along the middle Snake River during November 2012, the non-irrigation season, but not during July 2013, the irrigation season. During the November 2012 seepage study, the subreach between King Hill and C J Strike Dam had a meaningful (greater than cumulative measurement uncertainty) seepage gain of 415 cubic feet per second (ft3/s), and the subreach between Loveridge Bridge and C J Strike Dam had a meaningful seepage gain of 217 ft3/s. The meaningful seepage gain measured in the November 2012 seepage study was expected on the basis of several small seeps and springs present along the subreach, regional groundwater table contour maps, and results of regional groundwater flow model simulations. Computed seepage along the subreach from C J Strike Dam to Murphy was less than cumulative measurement uncertainty during November 2012 and July 2013; therefore, seepage cannot be quantified with certainty along this subreach. For the uncertainty evaluation, average

  9. Determination of beta activity in water

    USGS Publications Warehouse

    Barker, F.B.; Robinson, B.P.

    1963-01-01

    Many elements have one or more naturally radioactive isotopes, and several hundred other radionuclides have been produced artificially. Radioactive substances may be present in natural water as a result of geochemical processes or the release of radioactive waste and other nuclear debris to the environment. The Geological Survey has developed methods for measuring certain of these .radioactive substances in water. Radioactive substances often are present in water samples in microgram quantities or less. Therefore, precautions must be taken to prevent loss of material and to assure that the sample truly represents its source at the time of collection. Addition of acids, complexing agents, or stable isotopes often aids in preventing loss of radioactivity on container walls, on sediment, or on other solid materials in contact with the sample. The disintegration of radioactive atoms is a random process subject to established methods of statistical analysis. Because many water samples contain small amounts of radioactivity, low-level counting techniques must be used. The usual assumption that counting data follow a Gaussian distribution is invalid under these conditions, and statistical analyses must be based on the Poisson distribution. The gross beta activity in water samples is determined from the residue left after evaporation of the sample to dryness. Evaporation is accomplished first in a teflon dish, then the residue is transferred with distilled water to a counting planchet and again is reduced to dryness. The radioactivity on the planchet is measured with an anticoincidence-shielded, low-background, beta counter and is compared with measurements of a strontium-90-yttrium-90 standard prepared and measured in the same manner. Control charts are used to assure consistent operation of the counting instrument.

  10. Determination of uranium in natural waters

    USGS Publications Warehouse

    Barker, Franklin Butt; Johnson, J.O.; Edwards, K.W.; Robinson, B.P.

    1965-01-01

    A method is described for the determination of very low concentrations of uranium in water. The method is based on the fluorescence of uranium in a pad prepared by fusion of the dried solids from the water sample with a flux of 10 percent NaF 45.5 percent Na2CO3 , and 45.5 percent K2CO3 . This flux permits use of a low fusion temperature and yields pads which are easily removed from the platinum fusion dishes for fluorescence measurements. Uranium concentrations of less than 1 microgram per liter can be determined on a sample of 10 milliliters, or less. The sensitivity and accuracy of the method are dependent primarily on the purity of reagents used, the stability and linearity of the fluorimeter, and the concentration of quenching elements in the water residue. A purification step is recommended when the fluorescence is quenched by more than 30 percent. Equations are given for the calculation of standard deviations of analyses by this method. Graphs of error functions and representative data are also included.

  11. Chromatographic determination of solubilities in superheated water.

    PubMed

    Jones, Neil; Clifford, Anthony A; Bartle, Keith D; Myers, Peter

    2010-10-01

    Superheated water (SHW) is an effective solvent for the extraction of a variety of environmental pollutants, but knowledge of the solubilities in water at elevated temperatures necessary to maximise the efficiency of the process is often lacking. Ambient temperature aqueous solubilities have been measured by reverse-phase HPLC from correlations with retention factors, k, but for poorly soluble organics the eluent must contain a proportion of organic modifier followed by extrapolation to pure water. The use of SHW as mobile phase allows direct determination of aqueous solubility from measurement of k on a modified HPLC system in which the eluent is cooled before detection to improve baseline stability. Alumina-bonded octadecylsilane columns were found to be more stable in SHW chromatography than their silica-bonded counterparts. To validate the procedure, measurements of k were made between 100 and 200°C for toluene and correlated with literature solubilities; the solubilities at 170°C of a number of related aromatics were then determined from their k-values.

  12. Shallow gas hydrate within the areas of subaquatic seepage

    SciTech Connect

    Ginsburg, G.; Soloviev, V. )

    1993-09-01

    Sedimentary framework of worldwide hydrate-bearing areas and structures of sediments containing hydrates suggest that fluid filtration is the major process responsible for its generation. A study of seepage-associated hydrate accumulations that are accessible without drilling is useful for gaining an understanding of subaquatic gas hydrate formation general. Localities of shallow hydrate are indicative of oil and gas content. They also may be hazardous for oil and gas field development. The paper presents the results of exploration of gas hydrate accumulations that associate with diapirs, mud volcanoes, faults, subaquatic canyons, and pockmarks in the Caspian, Black, Okhotsk, and Barents seas. Data acquisition included echo sounding, seismic survey, ground sampling geothermic measurements, chemical and isotopic analyses of gas and water, definition of water content, and measurement of equilibrium pressures and temperatures. Hydrate content in sediments of discovered accumulations was up to 30-40% by volume. Somewhere, hydrate rests immediately on the bottom. Hydrate accumulation requires not only gas but also water input. It may be filtering either water bringing dissolved gas or pore/sea water migrating to meet gas diffusing bottomward. The models of gas hydrate formation have been developed for both gas-saturated water and free gas. Isotopic composition of water oxygen mainly results from exchange with carbonate inclusions rather than from the effect of hydrate fractionation. It is possible to evaluate hydrate content in sediments from the amount and composition of water.

  13. Catalytic determination of vanadium in water

    USGS Publications Warehouse

    Fishman, M. J.; Skougstad, M.W.

    1964-01-01

    A rapid, accurate, and sensitive spectrophotometric method for the quantitative determination of trace amounts of vanadium in water is based on the catalytic effect of vanadium on the rate of oxidation of gallic acid by persulfate in acid solution. Under given conditions of concentrations of reactants, temperature, and reaction time, the extent of oxidation of gallic acid is proportional to the concentration of vanadium present. Vanadium is determined by measuring the absorbance of the sample at 415 m?? and comparison with standard solutions treated in an identical manner. Concentrations in the range of from 0.1 to 8.0 ??g. per liter may be determined with a standard deviation of 0.2 or less. By reducing the reaction time, the method may be extended to cover the range from 1 to 100 ??g. with a standard deviation of 0.8 or less. Several substances interfere, including chloride above 100 p.p.m., and bromide and iodide in much lower concentrations. Interference from the halides is eliminated or minimized by the addition of mercuric nitrate solution. Most other substances do not interfere at the concentration levels at which they commonly occur in natural waters.

  14. Quantifying seepage using heat as a tracer in selected irrigation canals, Walker River Basin, Nevada, 2012 and 2013

    USGS Publications Warehouse

    Naranjo, Ramon C.; Smith, David W.

    2016-11-16

    The Walker River is an important source of water for western Nevada. The river provides water for agriculture and recharge to local aquifers used by several communities. Farmers began diverting water from the Walker River in the 1860s to support growing agricultural development. Over time, the reduced inflows into Walker Lake from upstream reservoirs and diversions have resulted in 170 feet of lake level decline and increased dissolved-solids concentrations to levels that threaten aquatic ecosystems, including survival of Lahonton cutthroat trout, a native species listed in the Endangered Species Act. Investigations of the water-budget components in the Walker River Basin have revealed uncertainty in the recharge to aquifers from irrigation canals. To address this need, the U.S. Geological Survey conducted an extensive field study from March 2012 through October 2013 to quantify seepage losses in selected canals in the Smith Valley, Mason Valley, and Walker Lake Valley irrigation areas.The seepage rates estimated for the 2012 and 2013 irrigation seasons in the Smith Valley transect sites (Saroni and Plymouth canals) ranged between 0.01 to 2.5 feet per day (ft/d) (0.01 to 0.68 cubic feet per second per mile [ft3/s-mi]). From 2012 to 2013, the average number of days the canals had flowing water decreased from 190 to 125 due to drier climate and lack of water available for diversion from the Walker River. The nearly 50-percent reductions in volumetric loss rates between 2012 and 2013 were associated with less than average diversions into canals from the Walker River and reductions in infiltration rates following routine canal maintenance.Models developed for the Saroni canal in 2012 were recalibrated in 2013 to evaluate changes in seepage as a result of siltation. Just prior to the 2012 irrigation season, nearly the entire length of the canal was cleared of vegetation and debris to improve flow conveyance. In 2013, following the first year of maintenance, a 90-percent

  15. An analytical solution for predicting the transient seepage from a subsurface drainage system

    NASA Astrophysics Data System (ADS)

    Xin, Pei; Dan, Han-Cheng; Zhou, Tingzhang; Lu, Chunhui; Kong, Jun; Li, Ling

    2016-05-01

    Subsurface drainage systems have been widely used to deal with soil salinization and waterlogging problems around the world. In this paper, a mathematical model was introduced to quantify the transient behavior of the groundwater table and the seepage from a subsurface drainage system. Based on the assumption of a hydrostatic pressure distribution, the model considered the pore-water flow in both the phreatic and vadose soil zones. An approximate analytical solution for the model was derived to quantify the drainage of soils which were initially water-saturated. The analytical solution was validated against laboratory experiments and a 2-D Richards equation-based model, and found to predict well the transient water seepage from the subsurface drainage system. A saturated flow-based model was also tested and found to over-predict the time required for drainage and the total water seepage by nearly one order of magnitude, in comparison with the experimental results and the present analytical solution. During drainage, a vadose zone with a significant water storage capacity developed above the phreatic surface. A considerable amount of water still remained in the vadose zone at the steady state with the water table situated at the drain bottom. Sensitivity analyses demonstrated that effects of the vadose zone were intensified with an increased thickness of capillary fringe, capillary rise and/or burying depth of drains, in terms of the required drainage time and total water seepage. The analytical solution provides guidance for assessing the capillary effects on the effectiveness and efficiency of subsurface drainage systems for combating soil salinization and waterlogging problems.

  16. Ground-based thermal imaging of groundwater flow processes at the seepage face

    NASA Astrophysics Data System (ADS)

    Deitchman, Richard S.; Loheide, Steven P.

    2009-07-01

    There is no existing method to quantitatively image groundwater processes along a seepage face. Thus, it is often difficult to quantify the magnitude and spatial variability of groundwater flux. The objective of this work is to assess the use of ground-based thermal remote sensing for fine-scale mapping of groundwater discharge and for locating the water table position along a stream bank seepage face. Seepage faces are poorly understood and often neglected in regional hydrologic studies though they likely exert significant influence on hydrologic and ecologic processes in riparian zones. Although the importance of riparian areas is broadly recognized, our ability to quantify hydrologic, ecologic and biogeochemical processes and ecosystem services is hampered by our inability to characterize spatially variable processes such as groundwater discharge. This work employs a new, transferable, non-invasive method that uses heat as a natural tracer to image spatially-variable groundwater flow processes and distinguish between focused and diffuse groundwater discharge to the surface. We report, for the first time, that thermal remote sensing of groundwater at the seepage face provides indirect imaging of both the saturated zone-unsaturated zone transition and groundwater flux at the centimeter scale, offering insight into flow heterogeneity.

  17. A method for estimating spatially variable seepage and hydrualic conductivity in channels with very mild slopes

    USGS Publications Warehouse

    Shanafield, Margaret; Niswonger, Richard G.; Prudic, David E.; Pohll, Greg; Susfalk, Richard; Panday, Sorab

    2014-01-01

    Infiltration along ephemeral channels plays an important role in groundwater recharge in arid regions. A model is presented for estimating spatial variability of seepage due to streambed heterogeneity along channels based on measurements of streamflow-front velocities in initially dry channels. The diffusion-wave approximation to the Saint-Venant equations, coupled with Philip's equation for infiltration, is connected to the groundwater model MODFLOW and is calibrated by adjusting the saturated hydraulic conductivity of the channel bed. The model is applied to portions of two large water delivery canals, which serve as proxies for natural ephemeral streams. Estimated seepage rates compare well with previously published values. Possible sources of error stem from uncertainty in Manning's roughness coefficients, soil hydraulic properties and channel geometry. Model performance would be most improved through more frequent longitudinal estimates of channel geometry and thalweg elevation, and with measurements of stream stage over time to constrain wave timing and shape. This model is a potentially valuable tool for estimating spatial variability in longitudinal seepage along intermittent and ephemeral channels over a wide range of bed slopes and the influence of seepage rates on groundwater levels.

  18. Combined use of thermal methods and seepage meters to efficiently locate, quantify, and monitor focused groundwater discharge to a sand-bed stream

    NASA Astrophysics Data System (ADS)

    Rosenberry, Donald O.; Briggs, Martin A.; Delin, Geoffrey; Hare, Danielle K.

    2016-06-01

    Quantifying flow of groundwater through streambeds often is difficult due to the complexity of aquifer-scale heterogeneity combined with local-scale hyporheic exchange. We used fiber-optic distributed temperature sensing (FO-DTS), seepage meters, and vertical temperature profiling to locate, quantify, and monitor areas of focused groundwater discharge in a geomorphically simple sand-bed stream. This combined approach allowed us to rapidly focus efforts at locations where prodigious amounts of groundwater discharged to the Quashnet River on Cape Cod, Massachusetts, northeastern USA. FO-DTS detected numerous anomalously cold reaches one to several m long that persisted over two summers. Seepage meters positioned upstream, within, and downstream of 7 anomalously cold reaches indicated that rapid groundwater discharge occurred precisely where the bed was cold; median upward seepage was nearly 5 times faster than seepage measured in streambed areas not identified as cold. Vertical temperature profilers deployed next to 8 seepage meters provided diurnal-signal-based seepage estimates that compared remarkably well with seepage-meter values. Regression slope and R2 values both were near 1 for seepage ranging from 0.05 to 3.0 m d-1. Temperature-based seepage model accuracy was improved with thermal diffusivity determined locally from diurnal signals. Similar calculations provided values for streambed sediment scour and deposition at subdaily resolution. Seepage was strongly heterogeneous even along a sand-bed river that flows over a relatively uniform sand and fine-gravel aquifer. FO-DTS was an efficient method for detecting areas of rapid groundwater discharge, even in a strongly gaining river, that can then be quantified over time with inexpensive streambed thermal methods.

  19. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    E. Sonnenthale

    2001-04-16

    The purpose of this Analysis/Model Report (AMR) is to document the Near-Field Environment (NFE) and Unsaturated Zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrologic-chemical (THC) processes on unsaturated zone flow and transport. This is in accordance with the ''Technical Work Plan (TWP) for Unsaturated Zone Flow and Transport Process Model Report'', Addendum D, Attachment D-4 (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M&O) 2000 [1534471]) and ''Technical Work Plan for Nearfield Environment Thermal Analyses and Testing'' (CRWMS M&O 2000 [153309]). These models include the Drift Scale Test (DST) THC Model and several THC seepage models. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal loading conditions, and predict the chemistry of waters and gases entering potential waste-emplacement drifts. The intended use of this AMR is to provide input for the following: Performance Assessment (PA); Near-Field Environment (NFE) PMR; Abstraction of Drift-Scale Coupled Processes AMR (ANL-NBS-HS-000029); and UZ Flow and Transport Process Model Report (PMR). The work scope for this activity is presented in the TWPs cited above, and summarized as follows: Continue development of the repository drift-scale THC seepage model used in support of the TSPA in-drift geochemical model; incorporate heterogeneous fracture property realizations; study sensitivity of results to changes in input data and mineral assemblage; validate the DST model by comparison with field data; perform simulations to predict mineral dissolution and precipitation and their effects on fracture properties and chemistry of water (but not flow rates) that may seep into drifts; submit modeling results to the TDMS and document the models. The model development, input data, sensitivity and validation studies described in this AMR are required

  20. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    E. Gonnenthal; N. Spyoher

    2001-02-05

    The purpose of this Analysis/Model Report (AMR) is to document the Near-Field Environment (NFE) and Unsaturated Zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrologic-chemical (THC) processes on unsaturated zone flow and transport. This is in accordance with the ''Technical Work Plan (TWP) for Unsaturated Zone Flow and Transport Process Model Report'', Addendum D, Attachment D-4 (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) 2000 [153447]) and ''Technical Work Plan for Nearfield Environment Thermal Analyses and Testing'' (CRWMS M and O 2000 [153309]). These models include the Drift Scale Test (DST) THC Model and several THC seepage models. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal loading conditions, and predict the chemistry of waters and gases entering potential waste-emplacement drifts. The intended use of this AMR is to provide input for the following: (1) Performance Assessment (PA); (2) Abstraction of Drift-Scale Coupled Processes AMR (ANL-NBS-HS-000029); (3) UZ Flow and Transport Process Model Report (PMR); and (4) Near-Field Environment (NFE) PMR. The work scope for this activity is presented in the TWPs cited above, and summarized as follows: continue development of the repository drift-scale THC seepage model used in support of the TSPA in-drift geochemical model; incorporate heterogeneous fracture property realizations; study sensitivity of results to changes in input data and mineral assemblage; validate the DST model by comparison with field data; perform simulations to predict mineral dissolution and precipitation and their effects on fracture properties and chemistry of water (but not flow rates) that may seep into drifts; submit modeling results to the TDMS and document the models. The model development, input data, sensitivity and validation studies described in

  1. Attention turns to naturally occurring methane seepage

    NASA Astrophysics Data System (ADS)

    Kvenvolden, Keith A.; Lorenson, Thomas D.; Reeburgh, William S.

    Methane is the most abundant organic compound in the Earth's atmosphere. As a powerful greenhouse gas, it has implications for global climate change. Sources of methane to the atmosphere are varied. Depending on the source, methane can contain either modern or ancient carbon. Methane exiting from swamps and wetlands contains modern carbon, whereas methane leaking from petroleum reservoirs contains ancient carbon. The total annual source of methane to the atmosphere has been constrained to about 540 teragrams (Tg) per year “Cicerone and Oremland, 1988”. Notably absent from any identified sources is the contribution of geologically sourced methane from naturally occurring seepage.

  2. Calibration and use of continuous heat-type automated seepage meters for submarine groundwater discharge measurements

    USGS Publications Warehouse

    Mwashote, B.M.; Burnett, W.C.; Chanton, J.; Santos, I.R.; Dimova, N.; Swarzenski, P.W.

    2010-01-01

    Submarine groundwater discharge (SGD) assessments were conducted both in the laboratory and at a field site in the northeastern Gulf of Mexico, using a continuous heat-type automated seepage meter (seepmeter). The functioning of the seepmeter is based on measurements of a temperature gradient in the water between downstream and upstream positions in its flow pipe. The device has the potential of providing long-term, high-resolution measurements of SGD. Using a simple inexpensive laboratory set-up, we have shown that connecting an extension cable to the seepmeter has a negligible effect on its measuring capability. Similarly, the observed influence of very low temperature (???3 ??C) on seepmeter measurements can be accounted for by conducting calibrations at such temperatures prior to field deployments. Compared to manual volumetric measurements, calibration experiments showed that at higher water flow rates (>28 cm day-1 or cm3 cm-2 day-1) an analog flowmeter overestimated flow rates by ???7%. This was apparently due to flow resistance, turbulence and formation of air bubbles in the seepmeter water flow tubes. Salinity had no significant effect on the performance of the seepmeter. Calibration results from fresh water and sea water showed close agreement at a 95% confidence level significance between the data sets from the two media (R2 = 0.98). Comparatively, the seepmeter SGD measurements provided data that are comparable to manually-operated seepage meters, the radon geochemical tracer approach, and an electromagnetic (EM) seepage meter. ?? 2009 Elsevier Ltd.

  3. Model Experiments and Elasto-Plastic Finite Element Analysis about Seepage Failure of Sand Behind Fixed Sheet Pile

    NASA Astrophysics Data System (ADS)

    Okajima, Kenji; Tanaka, Tadatsugu; Zhang, Shanji; Komatsu, Takahiro

    Constructing civil engineering structures, temporaly or permanent water proofing sheet piles often are used. The stability of seepage failure are carefully applied to those sheet piles, although many troubles of seepage failure were reported. On this problem the predictive method of the deformation and critical water head is required. In this study we carried out the model experiments which were designed for studying the seepage failure of soil behind fixed sheet piles and our elasto-plastic finite element method was applied to verify the effectiveness. Terzaghi method is very famous method for this problem and Terzaghi method was investigated by experiments data. As a result, it was confirmed that elasto-plastic finite element method was effectiveness and Terzaghi method was useful for this problem.

  4. Seepage study of Mapleton Lateral Canal near Mapleton, Utah, 2003

    USGS Publications Warehouse

    Wilkowske, Chris D.; Phillips, Jeff V.

    2004-01-01

    A study was conducted during the summer of 2003 on Mapleton Lateral Canal near Mapleton, Utah, to determine gain or loss of flow in the canal from seepage. Measurements were made in May, June, July, and September of 2003. The uppermost reach of the canal had an apparent average loss of 2.6 cubic feet per second. The next reach downstream showed an apparent average gain of 1.4 cubic feet per second. The next three downstream reaches had apparent average losses of 2.4, 2.5, and 2.7 cubic feet per second. The apparent average net loss from the canal was 8.8 cubic feet per second, or a loss of 30 percent of the total discharge measured at the head of the canal.

  5. Experimental Investigation of Seepage Properties of Fractured Rocks Under Different Confining Pressures

    NASA Astrophysics Data System (ADS)

    Ma, D.; Miao, X. X.; Chen, Z. Q.; Mao, X. B.

    2013-09-01

    The effectiveness of transmitting underground water in rock fractures is strongly influenced by the widths of the fractures and their interconnections. However, the geometries needed for water flow in fractured rock are also heavily controlled by the confining pressure conditions. This paper is intended to study the seepage properties of fractured rocks under different confining pressures. In order to do this, we designed and manufactured a water flow apparatus that can be connected to the electro-hydraulic servo-controlled test system MTS815.02, which provides loading and exhibits external pressures in the test. Using this apparatus, we tested fractured mudstone, limestone and sandstone specimens and obtained the relationship between seepage properties and variations in confining pressure. The calculation of the seepage properties based on the collection of water flow and confining pressure differences is specifically influenced by non-Darcy flow. The results show that: (1) The seepage properties of fractured rocks are related to confining pressure, i.e. with the increase of confining pressure, the permeability decreases and the absolute value of non-Darcy flow coefficient increases. (2) The sandstone coefficients and range from to m2 and to m-1, respectively, and exhibit a greater change compared to coefficients of mudstone and limestone. (3) From the regression analysis of experimental data, it is concluded that the polynomial function is a better fit than the power and logarithmic functions. The results obtained can provide an important reference for understanding the stability of rock surrounding roadways toward prevention of underground water gushing-out, and for developing underground resources (e.g. coal).

  6. Ecohydrology of seepage springs in an urban National Park

    NASA Astrophysics Data System (ADS)

    Knee, K.; Melone, J.; Friedel, B.; Fong, D.

    2014-12-01

    Shallow groundwater-fed seepage springs, also known as hypotelminorheic habitats, are found around the Washington, DC area, including in the George Washington Parkway, a National Park unit in northern Virginia. These springs differ from better-known vernal pools both in their hydrology and their ecology: because they are groundwater-fed, they are more resistant to drying out than vernal pools, and they harbor cave-adapted arthropod species including amphipods of the genus Stygobroumus. This project seeks to understand the ecohydrology of the hypotelminorheic habitats that support these species, some of which are endangered, and which comprise an important but underappreciated component of biodiversity in DC-area National Parks. Our study focuses on two hypotelminorheic habitats in the GW Parkway area and consists of three main components: (1) a weekly population census of Stygobroumus using multiple mark-recapture methodology, (2) weekly monitoring of dissolved radon, a tracer of groundwater discharge, as well as conductivity, dissolved oxygen, and pH, and (3) continuous logging of spring water temperature. This poster presents preliminary data from the Stygobroumus population census and explores how these animals may be affected by spring hydrology. Specifically, we use temperature, conductivity, radon activity and precipitation data from a nearby weather station to understand how the springs respond to episodic and seasonal variation in temperature, precipitation and groundwater seepage and how this affects Stygobromus populations. We also explore whether variations in Stygobromus counts reflect (1) active migration between the surficial spring and the larger subterranean habitat, or (2) passive flushing driven by groundwater discharge. Our results provide basic hydrologic data about a little-understood habitat type and will help managers protect Stygobromus in the urban park environment.

  7. Long-term groundwater transport of radionuclides from seepage basins at the Savannah River Site

    NASA Astrophysics Data System (ADS)

    Wiedmer, A.; Hunt, J. R.; Spycher, N.; Denham, M. E.

    2009-12-01

    The Savannah River Site (SRS) in South Carolina produced tritium and plutonium between 1953 and the beginning of the 1990s. The site released process wastewater containing plutonium, tritium, uranium, and fission products into seepage basins with the intent that short half-life radionuclides would decay in the years required for the groundwater to transport the waste materials to surface waters and that activity levels in the surface waters would not exceed levels considered appropriate in the 1950s. Between 1955 and 1988, the process operations at the F-area lead to the discharge of more than 12×106 cubic meters of low-level liquid radioactive waste solutions into unlined seepage basins. The waste contained longer half life nuclides that did not significantly decay during groundwater transit such as 3H (t½ = 12.28 years), 90Sr (t½ = 28.6 years), 99Tc (t½ = 2.13×105 years) and 129I (t½ = 1.57×107 years). Remediation started with the capping of the basin in 1990 followed by active plume pumping between 1997 and 2003. In 2004 a groundwater barrier was installed and in situ pH neutralization started in 2005. Tritium monitoring detected migration to Four Mile Creek by the end of the 1950s. Other radionuclides such as 90Sr, 99Tc and 129I have also been detected in groundwater seeping into the creek, and tritium levels and conductivity were well correlated at the seepage line. The seepage basin contaminated groundwater plume surfaced at seepage faces near a creek with a pH of 3. This acidity combined with high ionic strengths associated with nitrate mobilized contaminants such as 90Sr. The high levels of tritium, low pH and high conductivity at the seepage line show the likely importance of density driven flow for the salts of the plume and the limited dilution by groundwater flow. The Savannah River Site requires remediation to minimize radionuclide migration off-site, and there has been an extensive monitoring program of process waste discharges, groundwater

  8. H-Area Seepage Basins groundwater monitoring report. First quarter 1992

    SciTech Connect

    Thompson, C.Y.

    1992-06-01

    During first quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, antimony, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Site. This report presents and discusses the groundwater monitoring results in the H-Area for first quarter 1992.

  9. Utilizing geophysical methods for asessment and characterization of canal seepage in El Paso's lower valley irrigation delivery systems

    NASA Astrophysics Data System (ADS)

    Cegon, Amanda Brooke

    El Paso County Water Improvement District No. 1 (EPCWID No.1) delivers the Rio Grande water for agricultural production and urban uses through numerous networked irrigation canals. Of the nearly 86 billion gallons of water released annually for irrigation uses in Texas, billions are lost due to evaporation and seepage in unlined canals with 56 million gallons of the billions are lost in Franklin Canal annually due to improper lining and sediment variation of the canals. To characterize seepage patterns and identify areas of high seepage, Electrical Resistivity, Ground Truthing via soil sample analysis were used along three, half-mile long sectioned canals during irrigation and non-irrigation seasons. The data lines acquired were processed in EARTHIMAGER 2D to create 2D vertical resistivity inversion profiles to locate potential areas of high seepage/high resistivity. The research results will help El Paso County Water Improvement District No. 1 to develop management strategies to conserve water and improve the delivery efficiency systems which leads to economic growth in the Rio Grande Basin.

  10. Determination of dissolved aluminum in water samples

    USGS Publications Warehouse

    Afifi, A.A.

    1983-01-01

    A technique has been modified for determination of a wide range of concentrations of dissolved aluminum (Al) in water and has been tested. In this technique, aluminum is complexed with 8-hydroxyquinoline at pH 8.3 to minimize interferences, then extracted with methyl isobutyl ketone (MIBK). The extract is analyzed colorimetrically at 395 nm. This technique is used to analyze two forms of monomeric Al, nonlabile (organic complexes) and labile (free, Al, Al sulfate, fluoride and hydroxide complexes). A detection limit 2 ug/L is possible with 25-ml samples and 10-ml extracts. The detection limit can be decreased by increasing the volume of the sample and (or) decreasing the volume of the methyl isobutyl ketone extract. The analytical uncertainty of this method is approximately + or - 5 percent. The standard addition technique provides a recovery test for this technique and ensures precision in samples of low Al concentrations. The average percentage recovery of the added Al plus the amount originally present was 99 percent. Data obtained from analyses of filtered standard solutions indicated that Al is adsorbed on various types of filters. However, the relationship between Al concentrations and adsorption remains linear. A test on standard solutions also indicated that Al is not adsorbed on nitric acid-washed polyethylene and polypropylene bottle wells. (USGS)

  11. Infinite slope stability under steady unsaturated seepage conditions

    USGS Publications Warehouse

    Lu, N.; Godt, J.

    2008-01-01

    [1] We present a generalized framework for the stability of infinite slopes under steady unsaturated seepage conditions. The analytical framework allows the water table to be located at any depth below the ground surface and variation of soil suction and moisture content above the water table under steady infiltration conditions. The framework also explicitly considers the effect of weathering and porosity increase near the ground surface on changes in the friction angle of the soil. The factor of safety is conceptualized as a function of the depth within the vadose zone and can be reduced to the classical analytical solution for subaerial infinite slopes in the saturated zone. Slope stability analyses with hypothetical sandy and silty soils are conducted to illustrate the effectiveness of the framework. These analyses indicate that for hillslopes of both sandy and silty soils, failure can occur above the water table under steady infiltration conditions, which is consistent with some field observations that cannot be predicted by the classical infinite slope theory. A case study of shallow slope failures of sandy colluvium on steep coastal hillslopes near Seattle, Washington, is presented to examine the predictive utility of the proposed framework. Copyright 2008 by the American Geophysical Union.

  12. Infinite slope stability under steady unsaturated seepage conditions

    NASA Astrophysics Data System (ADS)

    Lu, Ning; Godt, Jonathan

    2008-11-01

    We present a generalized framework for the stability of infinite slopes under steady unsaturated seepage conditions. The analytical framework allows the water table to be located at any depth below the ground surface and variation of soil suction and moisture content above the water table under steady infiltration conditions. The framework also explicitly considers the effect of weathering and porosity increase near the ground surface on changes in the friction angle of the soil. The factor of safety is conceptualized as a function of the depth within the vadose zone and can be reduced to the classical analytical solution for subaerial infinite slopes in the saturated zone. Slope stability analyses with hypothetical sandy and silty soils are conducted to illustrate the effectiveness of the framework. These analyses indicate that for hillslopes of both sandy and silty soils, failure can occur above the water table under steady infiltration conditions, which is consistent with some field observations that cannot be predicted by the classical infinite slope theory. A case study of shallow slope failures of sandy colluvium on steep coastal hillslopes near Seattle, Washington, is presented to examine the predictive utility of the proposed framework.

  13. River Seepage Conductance in Large-Scale Regional Studies.

    PubMed

    Morel-Seytoux, Hubert J; Miller, Calvin D; Miracapillo, Cinzia; Mehl, Steffen

    2016-12-20

    Flow exchange between surface and groundwater is of great importance be it for beneficial allocation and use of water resources or for the proper exercise of water rights. In large-scale regional studies, most numerical models use coarse grid sizes, which make it difficult to provide an accurate depiction of the phenomenon. In particular, a somewhat arbitrary leakance coefficient in a third type (i.e., Cauchy, General Head) boundary condition is used to calculate the seepage discharge as a function of the difference of head in the river and in the aquifer, whose value is often found by calibration. A different approach is presented to analytically estimate that leakance coefficient. It is shown that a simple equivalence can be deduced from the analytical solution for the empirical coefficient, so that it provides the accuracy of the analytical solution while the model maintains a very coarse grid, treating the water-table aquifer as a single calculation layer. Relating the empirical leakance coefficient to the exact conductance, derived from physical principles, provides a physical basis for the leakance coefficient. Factors such as normalized wetted perimeter, degree of penetration of the river, presence of a clogging layer, and anisotropy can be included with little computational demand. In addition the river coefficient in models such as MODFLOW, for example, can be easily modified when grid size is changed without need for recalibration.

  14. Prototype development of an apparatus to locate and map sea floor petroleum seepages. Final technical report

    SciTech Connect

    1996-10-01

    The objective of the grant was to design, build, and test two autonomous instruments to measure vertical profiles of electrical potential in sea floor sediments. The objectives were fully met when the instruments were successfully deployed in 1,800 feet of water at known petroleum seepage sites in the Gulf of Mexico. The instruments were proven to be able to measure and record signals known to be appropriate to sediments altered by seepage. Two known seepage sites were visited on September 18th and 20th, 1996. At the first, a small-scale instrument capable of measuring 60 cm into the sediment was repeatedly emplaced by the manipulator arm of a research submarine, along a sea floor traverse. Further, the large-scale instrument, having a probe 3.3 m in length, was deployed by steel cable from the ship and emplaced in the sediment under gravity. Both successfully recorded data from multiple electrodes, revealing the expected negative potentials (Eh values at low at {minus}230 mV) at, and close to, the sediment-water interface, instead of at the normal depths of 3 to 4 m.

  15. Prototype development of an apparatus to locate and map sea floor petroleum seepages. Final technical report

    SciTech Connect

    Thompson, K.F.

    1997-12-31

    The objective of the grant was to design, build, and test two autonomous instruments to measure vertical profiles of electrical potential in sea floor sediments. The objectives were fully met when the instruments were successfully deployed in 1,800 feet of water at known petroleum seepage sites in the Gulf of Mexico. The instruments were proven to be able to measure and record signals known to be appropriate to sediments altered by seepage. Two known seepage sites were visited on September 18th and 20th, 1996. At the first, a small-scale instrument capable of measuring 60 cm into the sediment was repeatedly emplaced by the manipulator arm of a research submarine, along a sea floor traverse. Further, the large-scale instrument, having a probe 3.3 m in length, was deployed by steel cable from the ship and emplaced in the sediment under gravity. Both successfully recorded data from multiple electrodes, revealing the expected negative potentials (Eh values as low as {minus}230 mV) at, and close to, the sediment-water interface, instead of at the normal depths of 3 to 4 m.

  16. 76 FR 7762 - Drinking Water: Regulatory Determination on Perchlorate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... AGENCY 40 CFR Part 141 RIN 2040-AF08 Drinking Water: Regulatory Determination on Perchlorate AGENCY... the Agency's) regulatory determination for perchlorate in accordance with the Safe Drinking Water Act... occur or there is a substantial likelihood that perchlorate will occur in public water systems with...

  17. On the physics of unstable infiltration, seepage, and gravity drainage in partially saturated tuffs

    SciTech Connect

    Faybishenko, B.; Bodvarsson, G.S.; Salve, R.

    2002-04-01

    To improve understanding of the physics of dynamic instabilities in unsaturated flow processes within the Paintbrush nonwelded unit (PTn) and the middle nonlithophysal portion of the Tonopah Spring welded tuff unit (TSw) of Yucca Mountain, we analyzed data from a series of infiltration tests carried out at two sites (Alcove 4 and Alcove 6) in the Exploratory Studies Facility, using analytical and empirical functions. The analysis of infiltration rates measured at both sites showed three temporal scales of infiltration rate: (1) a macro-scale trend of overall decreasing flow, (2) a meso-scale trend of fast and slow motion exhibiting three-stage variations of the flow rate (decreasing, increasing, and [again] decreasing flow rate, as observed in soils in the presence of entrapped air), and (3) micro-scale (high frequency) fluctuations. Infiltration tests in the nonwelded unit at Alcove 4 indicate that this unit may effectively dampen episodic fast infiltration events; however, well-known Kostyakov, Horton, and Philip equations do not satisfactorily describe the observed trends of the infiltration rate. Instead, a Weibull distribution model can most accurately describe experimentally determined time trends of the infiltration rate. Infiltration tests in highly permeable, fractured, welded tuff at Alcove 6 indicate that the infiltration rate exhibits pulsation, which may have been caused by multiple threshold effects and water-air redistribution between fractures and matrix. The empirical relationships between the extrinsic seepage from fractures, matrix imbibition, and gravity drainage versus the infiltration rate, as well as scaling and self-similarity for the leading edge of the water front are the hallmark of the nonlinear dynamic processes in water flow under episodic infiltration through fractured tuff. Based on the analysis of experimental data, we propose a conceptual model of a dynamic fracture flow and fracture-matrix interaction in fractured tuff

  18. [Quantification study on the runoff and seepage distribution and N, P pollutants removal of the vegetated buffer strips].

    PubMed

    Wang, Min; Huang, Yu-Chi; Wu, Jian-Qiang

    2010-11-01

    By using the constructed buffer strips test base and the runoff hydrometric devices, a research on stagnant runoff and nitrogen (N), phosphorous (P) pollutants removal capacity of the vegetated buffer strips was conducted. The results show that the vegetated buffer strips might reduce the speed of runoff significantly and improve the hydraulic permeability of soil. The runoff water output time of 19 m buffer strips planted with Cynodon dactylon, Festuca arundinacea and Trifolium repens are 2.46, 1.72 and 2.03 times higher than the control (no vegetation) respectively; The seepage water quantity of three vegetation buffer strips are 3.01, 2.16 and 2.45 times higher than the control respectively as well. Total removal efficiency of the three buffer strips increase about 237%, 268% and 274% comparing with the control respectively. The N, P removal capacity of seepage is significantly higher than that of the runoff, the larger seepage water quantity will cause higher N, P total removal efficiency and removal loads of unit area. With different vegetated buffer strips, the TN, NH4(+) -N, TP removal ratio of seepage and runoff are 2.79, 2.02 and 2.83 respectively.

  19. Seepage investigation of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, 2015

    USGS Publications Warehouse

    Briody, Alyse C.; Robertson, Andrew J.; Thomas, Nicole

    2016-03-22

    Net seepage gain or loss was computed for each subreach (the interval between two adjacent measurement locations along the river) by subtracting the discharge measured at the upstream location from the discharge measured at the closest downstream location along the river and then subtracting any inflow to the river within the subreach. An estimated gain or loss was determined to be meaningful when it exceeded the cumulative measurement uncertainty associated with the net seepage computation. The cumulative seepage loss in the 64-mile study reach in 2015 was 17.3 plus or minus 2.6 cubic feet per second. Gaining and losing reaches identified in this investigation generally correspond to seepage patterns observed in previous investigations conducted during dry years, with the gaining reaches occurring primarily at the southern (downstream) end of the basin.

  20. H-Area Seepage Basins groundwater monitoring report

    SciTech Connect

    Not Available

    1993-03-01

    During fourth quarter 1992, the groundwater at the H-Area Seepage Basins (HASB) was monitored in compliance with South Carolina Hazardous Waste Management Regulations, R61-79.265, Subpart F. Samples were collected from 130 wells that monitor the three separate hydrostratigraphic units that make up the uppermost aquifer beneath the HASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B Post-Closure Care Permit Application for the H-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control in December 1990. Historically, as well as currently, tritium, nitrate, total alpha-emitting radium, gross alpha, and mercury have been the primary constituents observed above final Primary Drinking Water Standards (PDWS) in groundwater at the HASB. Isoconcentration/isoactivity maps included in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units during first and fourth quarter 1992. Water-level maps indicate that the groundwater flow rates and directions at the HASB have remained relatively constant since the basins ceased to be active in 1988.

  1. Modelling groundwater seepage zones in an unconfined aquifer with MODFLOW: different approaches

    NASA Astrophysics Data System (ADS)

    Leterme, Bertrand; Gedeon, Matej

    2014-05-01

    In areas where groundwater level occurs close to surface topography, the discharge of groundwater flow to the ground surface (or seepage) can be an important aspect of catchment hydrological cycle. It is also associated with valuable zones from an ecological point of view, often having a permanent shallow water table and constant lithotrophic water quality (Batelaan et al., 2003). In the present study, we try to implement a correct representation of this seepage process in a MODFLOW-HYDRUS coupled model for a small catchment (18.6 km²) of north-east Belgium. We started from an exisiting transient groundwater model of the unconfined aquifer in the study area (Gedeon and Mallants, 2009) discretized in 50x50 m cells. As the model did not account for seepage, hydraulic heads were simulated above the surface topography in certain zones. In the coupled MODFLOW-HYDRUS setup, transient boundary conditions (potential evapotranspiration and precipitation) are used to calculate the recharge with the HYDRUS package (Seo et al., 2007) for MODFLOW-2000 (Harbaugh et al., 2000). Coupling HYDRUS to MODFLOW involves the definition of a number of zones based on similarity in estimated groundwater depth, soil type and land cover. Concerning simulation of seepage, several existing packages are tested, including the DRAIN package (as in Reeve et al., 2006), the SPF package (from VSF Process; Thoms et al., 2006) and the PBC package (Post, 2011). Alternatively to the HYDRUS package for MODFLOW, the UZF package (Niswonger et al., 2006) for the simulation of recharge (and seepage) is also tested. When applicable, the parameterization of drain conductance in the top layer is critical and is investigated in relation to the soil hydraulic conductivity values used for the unsaturated zone (HYDRUS). Furthermore, stability issues are discussed, and where successful model runs are obtained, simulation results are compared with observed groundwater levels from a piezometric network. Spatial and

  2. Statistical analysis of liquid seepage in partially saturated heterogeneous fracture systems

    SciTech Connect

    Liou, Tai -Sheng

    1999-12-01

    Field evidence suggests that water flow in unsaturated fracture systems may occur along fast preferential flow paths. However, conventional macroscale continuum approaches generally predict the downward migration of water as a spatially uniform wetting front subjected to strong inhibition into the partially saturated rock matrix. One possible cause of this discrepancy may be the spatially random geometry of the fracture surfaces, and hence, the irregular fracture aperture. Therefore, a numerical model was developed in this study to investigate the effects of geometric features of natural rock fractures on liquid seepage and solute transport in 2-D planar fractures under isothermal, partially saturated conditions. The fractures were conceptualized as 2-D heterogeneous porous media that are characterized by their spatially correlated permeability fields. A statistical simulator, which uses a simulated annealing (SA) algorithm, was employed to generate synthetic permeability fields. Hypothesized geometric features that are expected to be relevant for seepage behavior, such as spatially correlated asperity contacts, were considered in the SA algorithm. Most importantly, a new perturbation mechanism for SA was developed in order to consider specifically the spatial correlation near conditioning asperity contacts. Numerical simulations of fluid flow and solute transport were then performed in these synthetic fractures by the flow simulator TOUGH2, assuming that the effects of matrix permeability, gas phase pressure, capillary/permeability hysteresis, and molecular diffusion can be neglected. Results of flow simulation showed that liquid seepage in partially saturated fractures is characterized by localized preferential flow, along with bypassing, funneling, and localized ponding. Seepage pattern is dominated by the fraction of asperity contracts, and their shape, size, and spatial correlation. However, the correlation structure of permeability field is less important

  3. Fault zone controlled seafloor methane seepage in the rupture area of the 2010 Maule earthquake, Central Chile

    NASA Astrophysics Data System (ADS)

    Geersen, Jacob; Scholz, Florian; Linke, Peter; Schmidt, Mark; Lange, Dietrich; Behrmann, Jan H.; Völker, David; Hensen, Christian

    2016-11-01

    Seafloor seepage of hydrocarbon-bearing fluids has been identified in a number of marine fore arcs. However, temporal variations in seep activity and the structural and tectonic parameters that control the seepage often remain poorly constrained. Subduction zone earthquakes, for example, are often discussed to trigger seafloor seepage but causal links that go beyond theoretical considerations have not yet been fully established. This is mainly due to the inaccessibility of offshore epicentral areas, the infrequent occurrence of large earthquakes, and challenges associated with offshore monitoring of seepage over large areas and sufficient time periods. Here we report visual, geochemical, geophysical, and modeling results and observations from the Concepción Methane Seep Area (offshore Central Chile) located in the rupture area of the 2010 Mw. 8.8 Maule earthquake. High methane concentrations in the oceanic water column and a shallow subbottom depth of sulfate penetration indicate active methane seepage. The stable carbon isotope signature of the methane and hydrocarbon composition of the released gas indicate a mixture of shallow-sourced biogenic gas and a deeper sourced thermogenic component. Pristine fissures and fractures observed at the seafloor together with seismically imaged large faults in the marine fore arc may represent effective pathways for methane migration. Upper plate fault activity with hydraulic fracturing and dilation is in line with increased normal Coulomb stress during large plate-boundary earthquakes, as exemplarily modeled for the 2010 earthquake. On a global perspective our results point out the possible role of recurring large subduction zone earthquakes in driving hydrocarbon seepage from marine fore arcs over long timescales.

  4. Stream seepage and groundwater levels, Wood River Valley, south-central Idaho, 2012-13

    USGS Publications Warehouse

    Bartolino, James R.

    2014-01-01

    Stream discharge and water levels in wells were measured at multiple sites in the Wood River Valley, south-central Idaho, in August 2012, October 2012, and March 2013, as a component of data collection for a groundwater-flow model of the Wood River Valley aquifer system. This model is a cooperative and collaborative effort between the U.S. Geological Survey and the Idaho Department of Water Resources. Stream-discharge measurements for determination of seepage were made during several days on three occasions: August 27–28, 2012, October 22–24, 2012, and March 27–28, 2013. Discharge measurements were made at 49 sites in August and October, and 51 sites in March, on the Big Wood River, Silver Creek, their tributaries, and nearby canals. The Big Wood River generally gains flow between the Big Wood River near Ketchum streamgage (13135500) and the Big Wood River at Hailey streamgage (13139510), and loses flow between the Hailey streamgage and the Big Wood River at Stanton Crossing near Bellevue streamgage (13140800). Shorter reaches within these segments may differ in the direction or magnitude of seepage or may be indeterminate because of measurement uncertainty. Additional reaches were measured on Silver Creek, the North Fork Big Wood River, Warm Springs Creek, Trail Creek, and the East Fork Big Wood River. Discharge measurements also were made on the Hiawatha, Cove, District 45, Glendale, and Bypass Canals, and smaller tributaries to the Big Wood River and Silver Creek. Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established by the U.S. Geological Survey in 2006. Maps of the October 2012 water-table altitude in the unconfined aquifer and the potentiometric-surface altitude of the confined aquifer have similar topology to those on maps of October 2006 conditions. Between October 2006 and October 2012, water-table altitude in the unconfined aquifer rose by

  5. F-Area seepage basins, groundwater quality assessment report, first quarter 1990

    SciTech Connect

    Not Available

    1990-06-01

    During the first quarter of 1990, wells which make up the F-Area Seepage Basins (F-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, gross alpha, and nonvolatile beta. The primary contaminants observed at wells monitoring the F-Area Seepage Basins are tritium, nitrate, cadmium, lead, total radium, gross alpha, and nonvolatile beta. Concentrations of at least one of the following constituents: tritium, nitrate, total radium, gross alpha, cadmium, lead, tetrachloroethylene, nonvolatile beta, endrin, lindane, barium, fluoride, mercury, and trichlorethylene in excess of the primary drinking water standard (PDWS) were observed in at least one well monitoring the F-Area Seepage Basins. Tritium concentrations above the PDWS occur in forty-four of the fifty-nine (75%) groundwater monitoring wells. Nitrate concentrations above the PDWS occur in thirty-four of the fifty-nine (59%) groundwater wells. The radionuclides, total radium, gross alpha, and nonvolatile beta, exceed the PDWS is over twenty-five percent of the groundwater wells. Heavy metals, cadmium and lead in particular, exceed the PDWS in over twelve percent of the wells. Since 1987, tritium and nitrate concentrations have been steadily declining in a majority of the wells. However, tritium concentrations, from fourth quarter 1989 to first quarter 1990, have increased.

  6. Measurement of seepage losses and chemical export from waste lagoons at animal feeding operations

    NASA Astrophysics Data System (ADS)

    Ham, J. M.; DeSutter, T. M.

    2001-05-01

    Whole-lagoon seepage rates were measured from 20 lagoons in Kansas using water balance techniques. Study sites included cattle feedlots, swine facilities, and one dairy. Seepage rates ranged from 0.2 mm/day to 2.4 mm/day with and overall average of 1.2 mm/day. Analysis of lagoon effluent (58 samples from 38 sites) indicated large differences in lagoon chemistry between locations. Ammonium nitrogen (NH4-N), which accounted for over 99 percent of the soluble nitrogen, ranged from 10 ppm to 3500 ppm. On average, nitrogen concentrations in swine lagoons were about five times higher than those at cattle feedlots. The chemical flux density (flux boundary condition) was estimated from the seepage rate and the corresponding waste chemistry data from each lagoon. Results showed that ammonium-N export was between 0.02 and 1.06 kg NH4-N m-2 yr^{-1} with an overall average of about 0.3 kg NH4-N m^{-2} yr^{-1}$ . Similar data are available for other soluble compounds. Soil cores were collected beneath eight lagoons that had been operated from 12 to 25 years. Results showed that NH4-N was strongly adsorbed by the soil clay particles and that nitrogen concentrations often decreased to background levels at 3 m beneath the lagoon. Other ions, such as chloride, penetrated to much lower depths at all locations. The 'reservoir' of NH4-N that exists beneath older lagoons could convert to nitrate and move to lower depths after lagoon closure. Data suggest that the properties if the soil beneath lagoons, the concentration of the waste, the seepage rate, and the depth to groundwater are the crucial factors that affect the risk of groundwater contamination.

  7. Groundwater seepage landscapes from distant and local sources in experiments and on Mars

    NASA Astrophysics Data System (ADS)

    Marra, W. A.; McLelland, S. J.; Parsons, D. R.; Murphy, B. J.; Hauber, E.; Kleinhans, M. G.

    2015-08-01

    Valleys with theater-shaped heads can form due to the seepage of groundwater and as a result of knickpoint (waterfall) erosion generated by overland flow. This ambiguity in the mechanism of formation hampers the interpretation of such valleys on Mars, particularly since there is limited knowledge of material properties. Moreover, the hydrological implications of a groundwater or surface water origin are important for our understanding of the evolution of surface features on Mars, and a quantification of valley morphologies at the landscape scale may provide diagnostic insights on the formative hydrological conditions. However, flow patterns and the resulting landscapes produced by different sources of groundwater are poorly understood. We aim to improve the understanding of the formation of entire valley landscapes through seepage processes from different groundwater sources that will provide a framework of landscape metrics for the interpretation of such systems. We study groundwater seepage from a distant source of groundwater and from infiltration of local precipitation in a series of sandbox experiments and combine our results with previous experiments and observations of the Martian surface. Key results are that groundwater flow piracy acts on valleys fed by a distant groundwater source and results in a sparsely dissected landscape of many small and a few large valleys. In contrast, valleys fed by a local groundwater source, i.e., nearby infiltration, result in a densely dissected landscape. In addition, valleys fed by a distant groundwater source grow towards that source, while valleys with a local source grow in a broad range of directions and have a strong tendency to bifurcate, particularly on flatter surfaces. We consider these results with respect to two Martian cases: Louros Valles shows properties of seepage by a local source of groundwater and Nirgal Vallis shows evidence of a distant source, which we interpret as groundwater flow from Tharsis.

  8. Quantifying spatial and temporal variability of groundwater-surface-water exchange in fluvial settings

    NASA Astrophysics Data System (ADS)

    Rosenberry, Donald

    2010-05-01

    Substantial spatial variability in flow across the sediment-water interface is now generally accepted as ubiquitous in hyporheic settings. A growing body of evidence indicates exchange also varies temporally, including frequent reversals in flow direction, on scales of minutes to hours to days. The extent of this dynamism, and the significance with regard to water chemistry and ecosystem viability and stability, have yet to be determined for many hyporheic settings. Anthropogenic influences create even greater variability through bed disturbance, and manipulation of stream and river flow, sediment supply, and surface-water and groundwater quality. In-situ measurements of seepage rate and direction were made along two river reaches, one located well downstream of any control structures and where bed mobility was common, and the other located several kilometers downstream of a dam where the bed was immobile nearly all of the time. Seepage meters modified for use in flowing water were used to measure rates of exchange between surface and sub-surface water in a sand-and-gravel-bed river in Colorado, USA (South Platte River, mean annual river discharge = 9.7 m3/s), and in a cobble-bed river in western Pennsylvania, USA (Allegheny River, mean annual river discharge = 188 m3/s). The median value of all seepage measurements at the South Platte River was 0.24 m/day, indicating a small to moderate rate of groundwater discharge to the river. However, substantial local-scale bed topography as well as mobile bedforms in the river resulted in spatial and temporal variability an order of magnitude larger than the median groundwater discharge rate. Both upward and downward seepage were recorded along every transect across the river with rates ranging from +2.37 (upward) to -3.40 (downward) m/day. At the Allegheny River site, moss and algae covered much of the bed and river grass was common, indicating greater bed stability than at the South Platte River site. Median seepage was +0

  9. F-Area Seepage Basins groundwater monitoring report

    SciTech Connect

    Not Available

    1993-03-01

    During fourth quarter 1992, the groundwater at the F-Area Seepage Basins (FASB) was monitored in compliance with South Carolina Hazardous Waste Management Regulations, R61-79.265, Subpart F. Eighty-five wells provided samples from the three hydrostratigraphic units that make up the uppermost aquifer beneath the FASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B Post-Closure Care Permit Application for the F-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control in December 1990. Historically, as well as currently, tritium, nitrate, gross alpha, total alpha-emitting radium, cadmium, and lead are the primary constituents observed above final Primary Drinking Water Standards (PDWS) in groundwater at the FASB. Nonvolatile beta has consistently exceeded its drinking water screening level. Other radionuclides and hazardous constituents also have exceeded the final PDWS in the groundwater at the FASB. The elevated constituents are found primarily in Aquifer Zone IIB[sub 2] (Water Table) and Aquifer Zone IIB[sub 1], (Barnwell/McBean) wells. However, several Aquifer Unit IIA (Congaree) wells also contain elevated levels of constituents, primarily tritium. Isoconcentration/isoactivity maps included in this report indicate both the concentration/ activity and extent of the primary contaminants in each of the three hydrostratigraphic units for first and fourth quarters 1992. Water-level maps indicate that the groundwater flow rates and directions at the FASB have remained relatively constant since the basins ceased to be active in 1988.

  10. Seepage studies of the Weber River and the Davis-Weber and Ogden Valley canals Davis and Weber Counties, Utah, 1985

    USGS Publications Warehouse

    Herbert, L.R.; Cruff, R.W.; Clark, D.W.; Avery, Charles

    1987-01-01

    Studies of selected reaches of the Weber River, Davis-Weber Canal, and the Ogden Valley Canal in Davis and Weber Counties, Utah, were made to determine gains or losses of flow in those reaches. Three to five sets of seepage measurements were made on the river and each canal during 1985. Adjustments for fluctuations in flow were made from information obtained from water-stage recorders operated at selected locations during the time of each set of seepage measurements. The studies indicated a loss of 20.0 cubic feet per second in the upstream reach of the Weber River and a gain of 17.0 cubic feet per second in the downstream reaches or a net loss of 3.0 cubic feet per second. Study results also indicated a net loss of 17.0 cubic feet per second in the Davis-Weber Canal and a net loss of 4.0 cubic feet per second in the Ogden Valley Canal.

  11. Seepage investigations of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, 2006-13

    USGS Publications Warehouse

    Crilley, D.M.; Matherne, A.M.; Thomas, Nicole; Falk, S.E.

    2013-01-01

    Seepage investigations were conducted annually by the U.S. Geological Survey from 1988 to 1998 and from 2004 to 2013 along a 64-mile reach of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, as part of the Mesilla Basin monitoring program. Results of studies conducted from 2006 to 2013 are presented in this report. Seepage investigations were conducted over a period of 1–2 days in February of each year, during low-flow conditions in the non-irrigation season. During the seepage investigations, discharge was measured at as many as 24 sites along the Rio Grande and as many as 20 inflow sites within the study reach. Net seepage gain or loss was computed for each subreach by subtracting the discharge measured at the upstream location from the discharge measured at the closest downstream location along the river and then subtracting any inflow to the river within the subreach. An estimated gain or loss was determined to be significant when it exceeded the cumulative measurement uncertainty associated with the net seepage computation. Study reaches during 2006 to 2013 ranged from 20.2 to 64 miles in length, and seepage losses ranged from 8.2 ± 3.1 to 47.9 ± 8.2 cubic feet per second.

  12. D-area oil seepage basin bioventing optimization test plan

    SciTech Connect

    Berry, C.J.; Radway, J.C.; Alman, D.; Hazen, T.C.

    1998-12-31

    The D Area Oil Seepage Basin (DOSB) was used from 1952 to 1975 for disposal of petroleum-based products (waste oils), general office and cafeteria waste, and apparently some solvents [trichloroethylene (TCE)/tetrachloroethylene (PCE)]. Numerous analytical results have indicated the presence of TCE and its degradation product vinyl chloride in groundwater in and around the unit, and of petroleum hydrocarbons in soils within the unit. The DOSB is slated for additional assessment and perhaps for environmental remediation. In situ bioremediation represents a technology of demonstrated effectiveness in the reclamation of sites contaminated with petroleum hydrocarbons and chlorinated solvents, and has been retained as an alternative for the cleanup of the DOSB. The Savannah River Site is therefore proposing to conduct a field treatability study designed to demonstrate and optimize the effectiveness of in situ microbiological biodegradative processes at the DOSB. The introduction of air and gaseous nutrients via two horizontal injection wells (bioventing) is expected to enhance biodegradation rates of petroleum components and stimulate microbial degradation of chlorinated solvents. The data gathered in this test will allow a determination of the biodegradation rates of contaminants of concern in the soil and groundwater, allow an evaluation of the feasibility of in situ bioremediation of soil and groundwater at the DOSB, and provide data necessary for the functional design criteria for the final remediation system.

  13. Snow water equivalent determination by microwave radiometry

    NASA Technical Reports Server (NTRS)

    Chang, A. T. C.; Foster, J. L.; Hall, D. K.; Rango, A.; Hartline, B. K.

    1981-01-01

    One of the most important parameters for accurate snowmelt runoff prediction is snow water equivalent (SWE) which is contentionally monitored using observations made at widely scattered points in or around specific watersheds. Remote sensors which provide data with better spatial and temporal coverage can be used to improve the SWE estimates. Microwave radiation, which can penetrate through a snowpack, may be used to infer the SWE. Calculations made from a microscopic scattering model were used to simulate the effect of varying SWE on the microwave brightness temperature. Data obtained from truck mounted, airborne and spaceborne systems from various test sites were studied. The simulated SWE compares favorable with the measured SWE. In addition, whether the underlying soil is frozen or thawed can be discriminated successfully on the basis of the polarization of the microwave radiation.

  14. Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden

    NASA Astrophysics Data System (ADS)

    Mau, S.; Römer, M.; Torres, M. E.; Bussmann, I.; Pape, T.; Damm, E.; Geprägs, P.; Wintersteller, P.; Hsu, C.-W.; Loher, M.; Bohrmann, G.

    2017-02-01

    Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02–7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard grounds, whereas glaciomarine and Holocene sediments in the troughs apparently limit seepage. The large scale seepage reported here is not caused by anthropogenic warming.

  15. Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden.

    PubMed

    Mau, S; Römer, M; Torres, M E; Bussmann, I; Pape, T; Damm, E; Geprägs, P; Wintersteller, P; Hsu, C-W; Loher, M; Bohrmann, G

    2017-02-23

    Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02-7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard grounds, whereas glaciomarine and Holocene sediments in the troughs apparently limit seepage. The large scale seepage reported here is not caused by anthropogenic warming.

  16. Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden

    PubMed Central

    Mau, S.; Römer, M.; Torres, M. E.; Bussmann, I.; Pape, T.; Damm, E.; Geprägs, P.; Wintersteller, P.; Hsu, C.-W.; Loher, M.; Bohrmann, G.

    2017-01-01

    Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02–7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard grounds, whereas glaciomarine and Holocene sediments in the troughs apparently limit seepage. The large scale seepage reported here is not caused by anthropogenic warming. PMID:28230189

  17. Hydrologic and geochemical approaches for determining ground-water flow components

    USGS Publications Warehouse

    Hjalmarson, H.W.; Robertson, F.N.

    1991-01-01

    Lyman Lake is an irrigation-storage reservoir on the Little Colorado River near St. Johns, Arizona. The main sources of water for the lake are streamflow in the Little Colorado River and ground-water inflow from the underlying Coconino aquifer. Two approaches, a hydrologic analysis and a geochemical analysis, were used to compute the quantity of ground-water flow to and from Lyman Lake. Hydrologic data used to calculate a water budget were precipitation on the lake, evaporation from the lake, transpiration from dense vegetation, seepage through the dam, streamflow in and out of the lake, and changes in lake storage. Geochemical data used to calculate the ground-water flow components were major ions, trace elements, and the stable isotopes of hydrogen and oxygen. During the study, the potentiometric level of the Coconino aquifer was above the lake level at the upstream end of the lake and below the lake level at the downstream end. Hydrologic and geochemical data indicate that about 10 percent and 8 percent, respectively, of the water in the lake is ground-water inflow and that about 35 percent of the water in the Little Colorado River 6 miles downgradient from the lake near Salado Springs is ground water. These independent estimates of ground-water flow derived from each approach are in agreement and support a conceptual model of the water budget.

  18. Methods to quantify seepage beneath Levee 30, Miami-Dade County, Florida

    USGS Publications Warehouse

    Sonenshein, R.S.

    2001-01-01

    A two-dimensional, cross-sectional, finite-difference, ground-water flow model and a simple application of Darcy?s law were used to quantify ground-water flow (from a wetlands) beneath Levee 30 in Miami-Dade County, Florida. Geologic and geophysical data, vertical seepage data from the wetlands, canal discharge data, ground-water-level data, and surface-water-stage data collected during 1995 and 1996 were used as boundary conditions and calibration data for the ground-water flow model and as input for the analytical model. Vertical seepage data indicated that water from the wetlands infiltrated the subsurface, near Levee 30, at rates ranging from 0.033 to 0.266 foot per day when the gates at the control structures along Levee 30 canal were closed. During the same period, stage differences between the wetlands (Water Conservation Area 3B) and Levee 30 canal ranged from 0.11 to 1.27 feet. A layer of low-permeability limestone, located 7 to 10 feet below land surface, restricts vertical flow between the surface water in the wetlands and the ground water. Based on measured water-level data, ground-water flow appears to be generally horizontal, except in the direct vicinity of the canal. The increase in discharge rate along a 2-mile reach of the Levee 30 canal ranged from 9 to 30 cubic feet per second per mile and can be attributed primarily to ground-water inflow. Flow rates in Levee 30 canal were greatest when the gates at the control structures were open. The ground-water flow model data were compared with the measured ground-water heads and vertical seepage from the wetlands. Estimating the horizontal ground-water flow rate beneath Levee 30 was difficult owing to the uncertainty in the horizontal hydraulic conductivity of the main flow zone of the Biscayne aquifer. Measurements of ground-water flows into Levee 30 canal, a substantial component of the water budget, were also uncertain, which lessened the ability to validate the model results. Because of vertical

  19. Effect of vegetation type on throughfall deposition and seepage flux.

    PubMed

    De Schrijver, A; Staelens, J; Wuyts, K; Van Hoydonck, G; Janssen, N; Mertens, J; Gielis, L; Geudens, G; Augusto, L; Verheyen, K

    2008-05-01

    This paper compares different vegetation types (coniferous and deciduous forest, grassed and pure heathland) in terms of input (throughfall deposition) and output (seepage flux) in a region with intermediate nitrogen load (+/-20kg Nha(-1)y(-1) via bulk precipitation) in comparable conditions in north Belgium. Coniferous forest (two plots Pinus sylvestris and two plots Pinus nigra) received significantly higher nitrogen and sulphur throughfall deposition than deciduous forest and heathland. Grassed and pure heathland had significantly highest throughfall quantities of Ca(2+) and Mg(2+), respectively. The observed differences in throughfall deposition between the different vegetation types were not univocally reflected in the ion seepage flux. Considerable seepage fluxes of NO(3)(-), SO(4)(2-), Ca(2+) and Al(III) were only found under the P. nigra plots. We discuss our hypothesis that the P. nigra forests already evolved to a situation of N saturation, while the other vegetation types did not.

  20. H-Area Seepage Basins Groundwater Monitoring Report: Volume 1, Third and Fourth quarters 1994

    SciTech Connect

    Chase, J.A.

    1994-03-01

    Isoconcentration/isocactivity maps included in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units during the second half of 1994. Geologic cross sections indicate both the extent and depth of contamination of the primary contaminants in all of the hydrostratigraphic units during the second half of 1994. Water-level maps indicate that the groundwater flow rates and directions at the H-Area Seepage Basins have remained relatively constant since the basins ceased to be active in 1988.

  1. F-Area Seepage Basins Groundwater Monitoring Report: Volume 1, Third and fourth quarters 1994

    SciTech Connect

    Chase, J.A.

    1994-03-01

    Isoconcentration/isoactivity maps included in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units. Geologic cross sections indicate both the extent and depth of contamination of the primary contaminants in all of the hydrostratigraphic units during the second half of 1994. Water-level maps indicate that the groundwater flow rates and directions at the F-Area Seepage Basins have remained relatively constant since the basins ceased to be active in 1988.

  2. Determinants of virtual water flows in the Mediterranean.

    PubMed

    Fracasso, Andrea; Sartori, Martina; Schiavo, Stefano

    2016-02-01

    The aim of the paper is to investigate the main determinants of the bilateral virtual water (water used in the production of a commodity or service) flows associated with international trade in agricultural goods across the Mediterranean basin. We consider the bilateral gross flows of virtual water in the area and study what export-specific and import-specific factors are significantly associated with virtual water flows. We follow a sequential approach. Through a gravity model of trade, we obtain a "refined" version of the variable we aim to explain, one that is free of the amount of flows due to pair-specific factors affecting bilateral trade flows and that fully reflects the impact of country-specific determinants of virtual water trade. A number of country-specific potential explanatory variables, ranging from water endowments to trade barriers, from per capita GDP to irrigation prices, is presented and tested. To identify the variables that help to explain the bilateral flows of virtual water, we adopt a model selection procedure based on model averaging. Our findings confirm one of the main controversial results in the literature: larger water endowments do not necessarily lead to a larger 'export' of virtual water, as one could expect. We also find some evidence that higher water irrigation prices reduce (increase) virtual water 'exports' ('imports').

  3. Re: Request for Correction: Drinking Water: Determination on Perchlorate

    EPA Pesticide Factsheets

    Request for correction (RFC) of information developed and relied upon by the Environmental Protection Agency (EPA or Agency) to support its determination to regulate perchlorate under the Safe Drinking Water Act (SDWA).

  4. Manual for Calculating the Seepage Strength of Earthfill Dams,

    DTIC Science & Technology

    1976-07-01

    CALCULATIN I’KNS33~aG IWRTR z 1111RIGII OIP EART FILL DM6S Nlt.4 by N. 1. Pavehich 0 ~ DOCUMENT ]IDENTIFICATION DISTRIBUTION STATEMENT A Approved for public...PROCESSING SEET *TC-5453*oo& MANUAL FOR CALCULATING THE SEEPAGE STRENGTH OF EARTH FILL DAMSIi Edited by M. P. Pavchich 0 Translated from RUSSIAN for WES...layer (layers) of soil material between the core (earth shield) and the fills of the dam, ensuring seepage strength for the core (shield), as well as

  5. Determination of total dissolved solids in water analysis

    USGS Publications Warehouse

    Howard, C.S.

    1933-01-01

    The figure for total dissolved solids, based on the weight of the residue on evaporation after heating for 1 hour at 180??C., is reasonably close to the sum of the determined constituents for most natural waters. Waters of the carbonate type that are high in magnesium may give residues that weigh less than the sum. Natural waters of the sulfate type usually give residues that are too high on account of incomplete drying.

  6. Determining pomegranate water and nitrogen requirements with drip irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite being an ancient crop there is limited knowledge on the water and nitrogen (N) requirements of pomegranate. We conducted research at the University of California, Kearney Agricultural Research and Extension Center (KARE) to determine the water and nitrogen requirements of a developing pomegr...

  7. Fiber Bragg grating-based performance monitoring of a slope model subjected to seepage

    NASA Astrophysics Data System (ADS)

    Zhu, Hong-Hu; Shi, Bin; Yan, Jun-Fan; Zhang, Jie; Zhang, Cheng-Cheng; Wang, Bao-Jun

    2014-09-01

    In the past few years, fiber optic sensing technologies have played an increasingly important role in the health monitoring of civil infrastructures. These innovative sensing technologies have recently been successfully applied to the performance monitoring of a series of geotechnical structures. Fiber optic sensors have shown many unique advantages in comparison with conventional sensors, including immunity to electrical noise, higher precision and improved durability and embedding capabilities; fiber optic sensors are also smaller in size and lighter in weight. In order to explore the mechanism of seepage-induced slope instability, a small-scale 1 g model test of the soil slope has been performed in the laboratory. During the model’s construction, specially fabricated sensing fibers containing nine fiber Bragg grating (FBG) strain sensors connected in a series were horizontally and vertically embedded into the soil mass. The surcharge load was applied on the slope crest, and the groundwater level inside of the slope was subsequently varied using two water chambers installed besides the slope model. The fiber optic sensing data of the vertical and horizontal strains within the slope model were automatically recorded by an FBG interrogator and a computer during the test. The test results are presented and interpreted in detail. It is found that the gradually accumulated deformation of the slope model subjected to seepage can be accurately captured by the quasi-distributed FBG strain sensors. The test results also demonstrate that the slope stability is significantly affected by ground water seepage, which fits well with the results that were calculated using finite element and limit equilibrium methods. The relationship between the strain measurements and the safety factors is further analyzed, together with a discussion on the residual strains. The performance evaluation of a soil slope using fiber optic strain sensors is proved to be a potentially effective

  8. Estimating Vadose Zone Drainage From a Capped Seepage Basin, F Area, Savannah River Site

    NASA Astrophysics Data System (ADS)

    Wan, J.; Tokunaga, T. K.; Denham, M.

    2011-12-01

    Large volumes of waste solutions were commonly discharged into unlined seepage basins at many different facilities in the past. Plutonium was extracted from depleted uranium from 1955 to 1988 at the F-Area within the Savannah River Site, with contaminated process waters disposed of in permeable seepage basins. The primarily acidic solutions contained radioactive components (including tritium, 129I, and multiple isotopes of U, Pu, Sr, and Cs), elevated nitrate, and some metals (Hg, Pb, Cd). Basin 3 was the largest F-Area seepage basin, covering 2.0 hectare, with the water table typically at about 20 m below the soil surface. The local groundwater flows at an average velocity of 200 m/y in the approximately 10 m thick shallow aquifer, and is underlain by the low permeability Tan Clay. We used nearly 20 years of groundwater quality data from a monitoring well immediately downstream of Basin 3 to estimate the post-closure drainage of waste solutions through its underlying vadose zone, into the shallow aquifer. The measurements of tritium, nitrate, and specific conductance, were used as plume tracers in our estimates of vadose zone drainage. These calculations indicate that early stages of post-closure waste drainage occurred with high fluxes (≈ 1 m/y), and quickly declined. However, even after 20 years, drainage continues at a low but significant rate of several cm/y. These estimated drainage fluxes can help constrain predictions on the waste plume behavior, especially with respect to its emerging trailing gradient and anticipated time scales suitable for monitored natural attenuation.

  9. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Dobson, Patrick F.; Ghezzehei, Teamrat A.; Cook, Paul J.; Rodríguez-Pineda, J. Alfredo; Villalba, Lourdes; de La Garza, Rodrigo

    2012-02-01

    A study of seepage occurring in an adit at the Nopal I uranium mine in Chihuahua, Mexico, was conducted as part of an integrated natural analogue study to evaluate the effects of infiltration and seepage on the mobilization and transport of radionuclides. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage. Field observations recorded between April 2005 and December 2006 indicate that seepage is highly heterogeneous with respect to time, location, and quantity. Seepage, precipitation, and fracture data were used to test two hypotheses: (1) that fast flow seepage is triggered by large precipitation events, and (2) that an increased abundance of fractures and/or fracture intersections leads to higher seepage volumes. A few zones in the back adit recorded elevated seepage volumes immediately following large (>20 mm/day) precipitation events, with transit times of less than 4 h through the 8-m thick rock mass. In most locations, there is a 1-6 month time lag between the onset of the rainy season and seepage, with longer times observed for the front adit. There is a less clear-cut relation between fracture abundance and seepage volume; processes such as evaporation and surface flow along the ceiling may also influence seepage.

  10. Determination of malachite green and its leuco form in water

    USGS Publications Warehouse

    Allen, J.L.; Meinertz, J.R.; Gofus, J.E.

    1992-01-01

    Liquid chromatographic (lc) analysis can detect malachite green residues in water at less than 10 mu-g/l. Water samples were concentrated on disposable diol columns, eluted with 0.05m P-toluene-sulfonic acid in methanol, and determined by reversed-phase lc. When combined with a lead oxide postcolumn reactor, the lc method can simultaneously determine both leuco and chromatic forms of malachite green. Recoveries averaged 95.4% For the chromatic form and 57.3% For the leuco form of malachite green oxalate and leuco malachite green in spiked pond water samples. Recoveries of the carbinol form of malachite green (an equilibrium product of the dye in water) from spiked tap water samples averaged 98.6%. Recoveries of leuco malachite green were low and ph-dependent.

  11. Model Assessment of Alternatives for Reducing Seepage from Buried Uranium Mill Talings at the Morton Ranch Site in Central Wyoming

    SciTech Connect

    Nelson, R. W.; Reisenauer, A. E.; Gee, G. W.

    1980-06-01

    The purpose of this study is to examine potential ground water contamination by seepage from buried tailings under four alternatives of clay liners and tailings placement, which have been proposed for possible use at the Morton Ranch Site. To accomplish this comparison of alternatives, laboratory work and numerous measurements were made on materials typical of the Morton Ranch Site. These measurements provide the soil characteristics necessary for input to the hydrologic flow and transport models.

  12. Seepage investigation on the Rio Grande from below Caballo Reservoir, New Mexico, to El Paso, Texas, 2012

    USGS Publications Warehouse

    Gunn, Mark A.; Roark, D. Michael

    2014-01-01

    A seepage investigation was conducted by the U.S. Geological Survey, in cooperation with the New Mexico Interstate Stream Commission, along an approximately 106-mile reach of the Rio Grande from below Caballo Reservoir, New Mexico, to El Paso, Texas, during June 26–28, 2012, to determine gain or loss of streamflow due to seepage to or from the river channel. Discharge measurements were made during the irrigation season at high flow including 5 sites along the Rio Grande, 5 diversions, and 63 inflows. The net gain or loss of flow in the river channel was computed for four reaches within the 106-mile reach of the Rio Grande. The normalized percentage difference was computed for each reach to determine the difference between discharge measured at upstream and downstream sites, and the normalized percentage uncertainty was computed to determine if a computed gain or loss exceeded cumulative uncertainty associated with measurement of discharge.

  13. Behavior of fiber reinforced sandy slopes under seepage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seepage flow is a major contributor to instability of natural hill slopes, river banks and engineered embankments. In order to increase the factor of safety, an emerging technology involves the inclusion of synthetic fibers in the soil. The addition of tension resisting fibers has a favorable effec...

  14. Geologic seepage of methane and light alkanes in Los Angeles

    NASA Astrophysics Data System (ADS)

    Doezema, L. A.; Chang, K.; Baril, R.; Nwachuku, I.; Contreras, P.; Marquez, A.; Howard, D.

    2013-12-01

    Natural geologic seepage of methane from underground oil and natural gas reservoirs has been suggested to be an underreported part of the global methane budget. Other light alkanes are also given off in combination with the methane seepage, making it possible that geologic seepage is also a potentially significant global source of these light alkanes. This study reports C1-C5 findings from geologic seepage made in the Los Angeles region. Microseepage, invisible escape of gases, was measured primarily at Kenneth Hahn Regional Park, while macroseepage, the visible release of gases, was measured at the La Brea Tar Pits. Samples were collected using stainless steel canisters and flux chambers and were analyzed using gas chromatography with flame ionization detectors (GC-FID). Average microseepage flux rates of 0.95 μg m-2 h-1 for ethane and 0.51 μg m-2 h-1 were found for propane, while average macroseepage rates for methane, ethane, and propane were 664, 19.8, and 18.1 mg m-2 h-1 respectively. Relationships between microseepage flux rate and location of underground oil and natural deposit and earthquake fault lines are presented. Additionally, the relative importance of findings in context with global budgets and local air quality is discussed.

  15. Seepage investigations of Noyes Canal, Menard County, Texas

    USGS Publications Warehouse

    Yost, Ivan Dale

    1953-01-01

    At the request of the U.S. Department of Agriculture, Soil Conservation Service, and the Menard Irrigation Company, a seepage investigation was made on Noyes Canal (Menard Irrigation Company Canal) in Menard County, Texas, from the headgates of the canal to where the canal empties back into the San Saba River.

  16. Summary of Seepage Investigations in the Yakima River Basin, Washington

    USGS Publications Warehouse

    Magirl, C.S.; Julich, R.J.; Welch, W.B.; Curran, C.R.; Mastin, M.C.; Vaccaro, J.J.

    2009-01-01

    Discharge data collected by the U.S. Geological Survey, Washington State Department of Ecology, and Yakama Nation for seepage investigations in the Yakima River basin are made available as downloadable Microsoft Excel files. These data were collected for more than a century at various times for several different studies and are now available in one location to facilitate future analysis by interested parties.

  17. 21 CFR 352.76 - Determination if a product is water resistant or very water resistant.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... making the claim of “water resistant,” the label SPF shall be the label SPF value determined after 40... claim of “very water resistant,” the label SPF shall be the label SPF value determined after 80...

  18. 21 CFR 352.76 - Determination if a product is water resistant or very water resistant.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... making the claim of “water resistant,” the label SPF shall be the label SPF value determined after 40... claim of “very water resistant,” the label SPF shall be the label SPF value determined after 80...

  19. 21 CFR 352.76 - Determination if a product is water resistant or very water resistant.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... making the claim of “water resistant,” the label SPF shall be the label SPF value determined after 40... claim of “very water resistant,” the label SPF shall be the label SPF value determined after 80...

  20. 21 CFR 352.76 - Determination if a product is water resistant or very water resistant.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... making the claim of “water resistant,” the label SPF shall be the label SPF value determined after 40... claim of “very water resistant,” the label SPF shall be the label SPF value determined after 80...

  1. 21 CFR 352.76 - Determination if a product is water resistant or very water resistant.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... making the claim of “water resistant,” the label SPF shall be the label SPF value determined after 40... claim of “very water resistant,” the label SPF shall be the label SPF value determined after 80...

  2. Effects of outcropping groundwater from the F- and H-Area seepage basins on the distribution of fish in Four Mile Creek

    SciTech Connect

    Paller, M.H.; Storey, C.

    1990-10-01

    Four Mile Creek was electrofished during June 26--July 2, 1990 to assess the impacts of outcropping ground water form the F- and H-Area Seepage Basins on fish abundance and distribution. Number of fish species and total catch were comparable at sample stations upstream from and downstream from the outcropping zone in Four Mile Creek. Species number and composition downstream from the outcropping zone in Four Mile Creek were similar to species number and composition in unimpacted portions of Pen Branch, Steel Creek, and Meyers Branch. These findings indicate that seepage basin outcropping was not adversely affecting the Four Mile Creek fish community. 5 refs., 3 figs., 4 tabs.

  3. Quantity and quality of seepage from two earthen basins used to store livestock waste in southern Minnesota during the first year of operation, 1997-98

    USGS Publications Warehouse

    Ruhl, James F.

    1999-01-01

    Seepage from the site B basin (based on 10 samples each from the bottom and sidewall) had chloride concentrations of 11 to 100 mg/L; ammonium-N concentrations of 2.58 mg/L or less; nitrate-N concentrations of 25.7 mg/L or less (except for one concentration of 146 mg/L); and organic-N concentrations of 0.92 mg/L or less. Nitrate-N concentrations in the seepage exceeded the U.S. Environmental Protection Agency (1996). MCL (maximum contaminant level) of 10 mg/L in 17 of 22 samples. Background ground-water quality, however, indicated that nitrate-N concentrations were greater than the MCL prior to operation of the basin. Fecal Coliform bacteria, as at the site A basin, were abundant in the basin wastewater, but not in the seepage.

  4. Monitoring of Potential Seepage Through Surface Sediments in the Sleipner Carbon Capture and Storage Area

    NASA Astrophysics Data System (ADS)

    James, R. H.; Lichtschlag, A.; Cevatoglu, M.; Reigstad, L.; Connelly, D.; Bull, J. M.

    2013-12-01

    Subseafloor Carbon Capture and Storage (CCS) has been recognized as critical technology for reducing the release of anthropogenic CO2 emissions to the atmosphere. However, the potential pathways of CO2 movement in the sedimentary overburden as well as the impact of any CO2 seepage from a storage site on the marine environment are poorly understood. As part of the ECO2 project, we have conducted a multidisciplinary survey of the area around Sleipner, which is one of the longest operated subseafloor CCS sites. Our aims were to: (1) Search for tracers of leakage of formation fluids or any other potential precursors of CO2 seepage, in the vicinity of the subseafloor CO2 plume. (2) Assess the potential for mobilization of toxic metals by CO2. (3) Characterize the environment in the vicinity of the Sleipner storage site. Potential pathways of seepage from the storage site were determined by the AUV AUTOSUB, that was equipped with a variety of instrumentation including sidescan sonar and an EM2000 multibeam systems, as well as a CHIRP profiler capable of inspecting the architecture of the sedimentary overburden. To detect geochemical indicators of leakage and their potential impact on the seafloor environment, the composition of fluids and gases were determined in the upper part of the sediment overburden (up to 3.8 m below seafloor), which was recovered by vibrocoring. The microbial activity in these sediments was also determined, by measuring the RNA content of selected cores. In this presentation we will compare the results that we have obtained from the area above the CO2 plume with results from an area ~20 km the north of the Sleipner platform (Hugin fracture). The Hugin fracture is several km long, and pore fluids from sediments recovered from the fracture have a distinctively different composition, with depletion of sulphate and chloride and increase of sulphide, dissolved inorganic carbon and total alkalinity. Assessing the natural variation in the sedimentary

  5. Migration of acidic groundwater seepage from uranium-tailings impoundments, 1. Field study and conceptual hydrogeochemical model

    NASA Astrophysics Data System (ADS)

    Morin, Kevin A.; Cherry, John A.; Dave, Nand K.; Lim, Tjoe P.; Vivyurka, Al J.

    1988-08-01

    In this first paper of a series, the results of a study at a non-operational tailings site are presented and are used to construct a general conceptual model for seepage migration from uranium-tailings impoundments. Many parts of the model are applicable to other types of tailings and to acid drainage in general. At the field site, the impoundment lies over a portion of a glaciofluvial sand aquifer. Tailings seepage drains downward into the aquifer and then migrates laterally away. Results of the field study indicate the seepage can be divided into three geochemical zones: (1) the inner core, which is essentially unaltered, acidic seepage from the tailings; (2) the neutralization zone, in which inner-core water is neutralized and aqueous concentrations decrease significantly; and (3) the outer zone, which contains both neutralized water from the neutralization zone and pH-neutral process water from the uranium milling operation. Yearly comparisons from 1979 to 1984 indicate the neutralization zone and inner core are migrating downgradient at a rate of about 1 meter/year, which is about 1/440 of the groundwater velocity. The mechanisms that produce the retardation and the decreases in aqueous concentrations are part of the conceptual model. The main features of the conceptual model are solid-liquid interactions, particularly mineral precipitation-dissolution, and buffering effects of dominant aqueous species. The important minerals undergoing precipitation-dissolution are the calcite-siderite solid solution, gypsum, Al-OH minerals, and Fe-OH minerals. "Cell and streamtube" calculations are used to evaluate the general trends in aqueous concentrations and to assist in explaining observed migration rates. Co-precipitation with the above minerals apparently accounts for decreases in other major, minor, and metal solutes. Because of the large amount of mineral precipitation and co-precipitation, variations in 2H and 18O were observed over a flow distance of several

  6. Quantifying Seepage Flux using Sediment Temperatures

    EPA Science Inventory

    This report provides a demonstration of different modeling approaches that use sediment temperatures to estimate the magnitude and direction of water flux across the groundwater-surface water transition zone. Analytical models based on steady-state or transient temperature solut...

  7. Methane Seepage at Hyperalkaline Springs in the Ronda Peridotite Massif (Spain)

    NASA Astrophysics Data System (ADS)

    Etiope, G.; Vadillo, I.; Whiticar, M. J.; Marques, J. M.; Carreira, P. M.; Tiago, I.; Benavente, J.; Jimenez, P.; Urresti, B.

    2014-12-01

    Methane-rich, hyperalkaline spring waters and bubbling pools have been sampled in the Ronda peridotite massif in southern Spain. Water chemistry (T: 17.1-21.5 ºC; pH: 10.7-11.7; DO: <2 mg/L; Ca-OH facies) is characteristic of present-day serpentinization. Dissolved CH4 concentrations range from 0.1 to 3.2 mg/L. CH4 stable C and H isotope ratios suggest a dominant abiotic origin in two natural spring sites (delta13C: -13 to -29 ‰ VPDB; delta2H: -309 to -333 ‰ VSMOW) and a mixed biotic-abiotic origin in springs with artificial water delivery systems (i.e., pipes or fountains; delta13C: -44 to -69 ‰; delta2H: -180 to -319 ‰). At the natural springs, gas is mainly released through bubbles close to the water outlet (CH4 flux ~1 kg/day by individual bubble trains), and subordinately by microseepage from the ground, even at distances of ~100 m from the bubble-spring site (flux of 10's, up to 97, mg CH4 m-2day-1). Gas seepage is strictly controlled by faults. Under-saturation of CH4 in water, bubbling and seepage location suggest that CH4 is not exclusively transported to the surface by hyperalkaline water, but it follows autonomous migration pathways along faults. Similar 'dry' seepage of abiotic gas was observed in the Philippines, New Zealand, Turkey and Italy. Like other land-based serpentinization systems, the Ronda peridotite massif is characterized by low heat flow (<40 mW/m2), with temperatures <60°C at depths of 1.5 km. At these low T and high pH conditions, CO32- is the only available carbon source dissolved in the water, and unlikely contributes to catalysed Fischer-Tropsch Type reactions. Methane production from CO2 hydrogenation in a gas phase system (unsaturated fractured rocks) cannot be excluded. The presence of ruthenium-enriched chromitites in the Ronda peridotites may support the hypothesis that CH4 is produced by CO2 hydrogenation catalyzed by Ru minerals, even at temperatures below 100°C, as demonstrated in recent laboratory experiments

  8. Elemental chemistry of sand-boil discharge used to trace variable pathways of seepage beneath levees during the 2011 Mississippi River flood

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water samples were collected from the Mississippi River, from sand boils near the toe of the levee on the Mississippi side of the river, and from actively flowing relief wells shortly after peak stage of the 2011 Mississippi River flood. Two distinct pathways for seepage under the levee were identif...

  9. Coupling Seepage and Radionuclide Transport in and Around Emplacement Drifts at Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Zhang, G.; Spycher, N.; Sonnenthal, E.; Steefel, C.

    2007-12-01

    The proposed nuclear waste repository of the United States is located at Yucca Mountain, Nevada. Waste packages will be placed in deep (~350 m) underground drifts in volcanic tuff. Seepage may potentially occur at the repository drifts when the drifts get rewetted after a dryout period. The potential seepage water will be quickly evaporated or boiled to near dryness as long as it falls on the top of the hot waste package leading to formation of brine, precipitation of salts and volatilization of gases. These processes may potentially impact the long-term safety of waste packages in the drift. The objectives of this study are to: (1) develop a quantitative model of coupled thermal, hydrological, and chemical (THC) processes potentially leading to brine formation, salt precipitation and gas volatilization on top of waste packages and/or a drip shield and (2) dynamically integrate such a model into the larger-scale models of processes within and around waste emplacement drifts, as well as into the smaller-scale waste-package corrosion models. Process models were implemented into an existing reactive transport numerical simulator, TOUGHREACT, to allow modeling of (1) evaporative concentration to very high ionic strength (up to 40 molal), (2) boiling point elevation due to dissolved salts, (3) boiling/evaporation to dryness, and (4) salt deliquescence. An integrated near-field and in-drift THC simulation was run using a vertical 2-D grid extending from near the ground surface to the groundwater table, and covering a width equal to half the design drift spacing of 81 m. The integrated model was then used to simulate a discrete dripping event within the drift. The model considered the release of radionuclides into seepage water as this water contacts the waste package and flows through the invert. The precipitation of uranophane and Np-uranophane was also considered. These minerals form in the invert from the neutralization of mildly acidic seepage water by clay minerals

  10. Community and household determinants of water quality in coastal Ghana.

    PubMed

    McGarvey, Stephen T; Buszin, Justin; Reed, Holly; Smith, David C; Rahman, Zarah; Andrzejewski, Catherine; Awusabo-Asare, Kofi; White, Michael J

    2008-09-01

    Associations between water sources, socio-demographic characteristics and household drinking water quality are described in a representative sample of six coastal districts of Ghana's Central Region. Thirty-six enumeration areas (EAs) were randomly chosen from a representative survey of 90 EAs in rural, semi-urban and urban residence strata. In each EA, 24 households were randomly chosen for water quality sampling and socio-demographic interview. Escherichia coli per 100 ml H2O was quantified using the IDEXX Colilert system and multi-stage regression models estimated cross-sectional associations between water sources, sanitation and socio-demographic factors. Almost three quarters, 74%, of the households have > 2 E. coli /100 ml H2O. Tap water has significantly lower E. coli levels compared with surface or rainwater and well water had the highest levels. Households with a water closet toilet have significantly lower E. coli compared with those using pit latrines or no toilets. Household size is positively associated, and a possessions index is negatively associated, with E. coli. Variations in community and household socio-demographic and behavioural factors are key determinants of drinking water quality. These factors should be included in planning health education associated with investments in water systems.

  11. Coulometric Karl Fischer determination of trace amounts of water

    SciTech Connect

    Nichugovskii, G.F.

    1986-06-01

    The authors maintain that it is convenient to determine small amounts of water by coulometric titration in spent Fischer reagent because this method is highly sensitive and provides an absolute measurement. The water content of the sample is calculated from the amount of electricity consumed in the electrochemical production of enough molecular iodine to bond completely with the water. This paper attempts to correct for the effect of various factors on the indicator current in the coulometric titration of trace quantities of water by the Karl Fischer reagent. The paper discusses the sources of error by biamperometric indication of the titration endpoint. When the water content is lower than 0.001%, it is absolutely necessary according to the authors, to correct for the effect of the analytical sample. Analytical and graphical methods of calculating the correction are suggested.

  12. Determination of the Water Content of Snow by Dielectric Measurements

    DTIC Science & Technology

    1992-07-01

    AD- A256 299 R*UIIUIUIIII• 0P Determination of the Water Content of Snow by Dielectric Measurements Paul R. Camp and David R. LaBrecque July 1992 a...kHz to deterrnlne wfether measurements made In this frequency range might prove useful in evaluating the water content of snow. Dielectric heating at...20 kHz proved a very useful means of modifying the water content from 0 to 30% by weight. Six different natural snows were used in these experiments

  13. Determination of phosphorus in natural waters: A historical review.

    PubMed

    Worsfold, Paul; McKelvie, Ian; Monbet, Phil

    2016-04-28

    The aim of this paper is to introduce a virtual special issue that reviews the development of analytical approaches to the determination of phosphorus species in natural waters. The focus is on sampling and sample treatment, analytical methods and quality assurance of the data. The export of phosphorus from anthropogenic activities (from diffuse and point sources) can result in increased primary production and eutrophication, and potentially the seasonal development of toxic algal blooms, which can significantly impact on water quality. Therefore the quantification of phosphorus species in natural waters provides important baseline data for studying aquatic phosphorus biogeochemistry, assessing ecosystem health and monitoring compliance with legislation.

  14. Determining gold in water by anion-exchange batch extraction

    USGS Publications Warehouse

    McHugh, J.B.

    1986-01-01

    This paper describes a batch procedure for determining gold in natural waters. It is completely adaptable to field operations. The water samples are filtered and acidified before they are equilibrated with an anion-exchange resin by shaking. The gold is then eluted with acetone-nitric acid solution, and the eluate evaporated to dryness. The residue is taken up in hydrobromic acid-bromine solution and the gold is extracted with methyl isobutyl ketone. The extract is electrothermally atomized in an atomic-absorption spectrophotometer. The limit of determination is 1 ng 1. ?? 1986.

  15. Determination of the taste threshold of copper in water.

    PubMed

    Zacarías, I; Yáñez, C G; Araya, M; Oraka, C; Olivares, M; Uauy, R

    2001-01-01

    Copper effects on human health represent a relevant issue in modern nutrition. One of the difficulties in assessing the early, acute effects of copper ingested via drinking water is that the taste of copper may influence the response and the capacity to taste copper in different waters is unknown. The purpose of the study was to determine the taste threshold of copper in different types of water, using soluble and insoluble salts (copper sulfate and copper chloride). Copper-containing solutions (range 1.0-8.0 mg/l Cu) were prepared in tap water, distilled deionized water and uncarbonated mineral water. Sixty-one healthy volunteers (17-50 years of age), with no previous training for sensory evaluation, participated in the study. A modified triangle test was used to define the taste threshold value. The threshold was defined as the lowest copper concentration detected by 50% of the subjects assessed. To evaluate the olfactory input in the threshold value obtained, 15 of 61 subjects underwent a second set of triangle tests with the nose open and clamped, using distilled water with copper sulfate at a concentration corresponding to the individual's threshold. The taste threshold in tap water was 2.6 mg/l Cu for both copper sulfate and copper chloride. The corresponding values for distilled deionized water were 2.4 and 2.5 mg/l Cu for copper sulfate and copper chloride, respectively. In uncarbonated mineral water the threshold values were slightly higher, 3.5 and 3.8 mg/l Cu for copper sulfate and for copper chloride, respectively, which are significantly higher than those observed in tap and distilled waters (P < 0.01, Kruskal-Wallis test). The taste threshold did not change significantly when the nose was clamped. In conclusion, the median values for copper taste threshold were low, ranging between 2.4 and 3.8 mg/l Cu, depending on the type of water.

  16. Groundwater flow and heterogeneous discharge into a seepage lake: Combined use of physical methods and hydrochemical tracers

    NASA Astrophysics Data System (ADS)

    Kazmierczak, J.; Müller, S.; Nilsson, B.; Postma, D.; Czekaj, J.; Sebok, E.; Jessen, S.; Karan, S.; Stenvig Jensen, C.; Edelvang, K.; Engesgaard, P.

    2016-11-01

    Groundwater discharge into a seepage lake was investigated by combining flux measurements, hydrochemical tracers, geological information, and a telescopic modeling approach using first two-dimensional (2-D) regional then 2-D local flow and flow path models. Discharge measurements and hydrochemical tracers supplement each other. Discharge measurements yield flux estimates but rarely provide information about the origin and flow path of the water. Hydrochemical tracers may reveal the origin and flow path of the water but rarely provide any information about the flux. While aquifer interacting with the lake remained under seemingly steady state conditions across seasons, a high spatial and temporal heterogeneity in the discharge to the lake was observed. The results showed that part of the groundwater flowing from the west passes beneath the lake and discharges at the eastern shore, where groundwater springs and high discharge zones (HDZs) are observed at the lake bottom and at seepage faces adjacent to the lake. In the 2-D cross section, surface runoff from the seepage faces delivers 64% of the total groundwater inputs to the lake, and a 2 m wide offshore HDZ delivers 13%. Presence of HDZs may control nutrient fluxes to the lake.

  17. ASSESSMENT OF HYDROCARBON SEEPAGE DETECTION METHODS ON THE FORT PECK RESERVATION, NORTHEAST MONTANA

    SciTech Connect

    Lawrence M. Monson

    2003-06-30

    Surface exploration techniques have been employed in separate study areas on the Fort Peck Reservation in northeastern Montana. Anomalies associated with hydrocarbon seepage are documented in all three areas and a variety of surface exploration techniques can be compared. In a small area with established production, Head Gas and Thermal Desorption methods best match production; other methods also map depletion. In a moderate-size area that has prospects defined by 3D seismic data, Head Gas along with Microbial, Iodine, and Eh soil anomalies are all associated with the best hydrocarbon prospect. In a large area that contains many curvilinear patterns observed on Landsat images, that could represent micro-seepage chimneys, results are inconclusive. Reconnaissance mapping using Magnetic Susceptibility has identified a potential prospect; subsequent Soil Gas and Head Gas surveys suggest hydrocarbon potential. In the final year of this project the principle contractor, the Fort Peck Tribes, completed a second survey in the Wicape 3D Seismic Prospect Area (also known as Area 6 in Phase I of the project) and sampled several Landsat image features contained in the Smoke Creek Aeromag Anomaly Area (also known as Area 1 in Phase II of the project). Methods determined to be most useful in Phases I and II, were employed in this final Phase III of the study. The Southwest Wicape seismic anomaly was only partially confirmed. The abundant curvilinears proposed to be possible hydrocarbon micro-seepage chimneys in the Smoke Creek Area were not conclusively verified as such. Insufficient sampling of background data precludes affirmative identification of these mostly topographic Landsat features as gas induced soil and vegetation anomalies. However relatively higher light gas concentrations were found associated with some of the curvilinears. Based on the findings of this work the Assiniboine & Sioux Tribes of the Fort Peck Reservation intend to utilize surface hydrocarbon

  18. The role of optimality in characterizing CO2 seepage from geological carbon sequestration sites

    SciTech Connect

    Cortis, Andrea; Oldenburg, Curtis M.; Benson, Sally M.

    2008-09-15

    Storage of large amounts of carbon dioxide (CO{sub 2}) in deep geological formations for greenhouse gas mitigation is gaining momentum and moving from its conceptual and testing stages towards widespread application. In this work we explore various optimization strategies for characterizing surface leakage (seepage) using near-surface measurement approaches such as accumulation chambers and eddy covariance towers. Seepage characterization objectives and limitations need to be defined carefully from the outset especially in light of large natural background variations that can mask seepage. The cost and sensitivity of seepage detection are related to four critical length scales pertaining to the size of the: (1) region that needs to be monitored; (2) footprint of the measurement approach, and (3) main seepage zone; and (4) region in which concentrations or fluxes are influenced by seepage. Seepage characterization objectives may include one or all of the tasks of detecting, locating, and quantifying seepage. Each of these tasks has its own optimal strategy. Detecting and locating seepage in a region in which there is no expected or preferred location for seepage nor existing evidence for seepage requires monitoring on a fixed grid, e.g., using eddy covariance towers. The fixed-grid approaches needed to detect seepage are expected to require large numbers of eddy covariance towers for large-scale geologic CO{sub 2} storage. Once seepage has been detected and roughly located, seepage zones and features can be optimally pinpointed through a dynamic search strategy, e.g., employing accumulation chambers and/or soil-gas sampling. Quantification of seepage rates can be done through measurements on a localized fixed grid once the seepage is pinpointed. Background measurements are essential for seepage detection in natural ecosystems. Artificial neural networks are considered as regression models useful for distinguishing natural system behavior from anomalous behavior

  19. Seepage phenomena on Mars at subzero temperature

    NASA Astrophysics Data System (ADS)

    Kereszturi, Akos; Möhlmann, Diedrich; Berczi, Szaniszlo; Ganti, Tibor; Horvath, Andras; Kuti, Adrienn; Pocs, Tamas; Sik, Andras; Szathmary, Eors

    At the southern hemisphere of Mars seasonal slope structures emanating from Dark Dune Spots are visible on MGS MOC, and MRO HiRISE images. Based on their analysis two groups of streaks could be identified: diffuse and fan shaped ones forming in an earlier phase of local spring, probably by CO2 gas jets, and confined streaks forming only on steep slopes during a later seasonal phase. The dark color of the streaks may arise from the dark color of the dune grains where surface frost disappeared above them, or caused by the phase change of the water ice to liquid-like water, or even it may be influenced by the solutes of salts in the undercooled interfacial water The second group's morphology (meandering style, ponds at their end), morphometry, and related theoretical modelling suggest they may form by undercooled water that remains in liquid phase in a thin layer around solid grains. We analyzed sequence of images, temperature and topographic data of Russel (54S 12E), Richardson (72S 180E) and an unnamed crater (68S 2E) during southern spring. The dark streaks here show slow motion, with an average speed of meter/day, when the maximal daytime temperature is between 190 and 220 K. Based on thermophysical considerations a thin layer of interfacial water is inevitable on mineral surfaces under the present conditions of Mars. With 10 precipitable micrometer of atmospheric water vapor, liquid phase can be present down about 190 K. Under such conditions dark streaks may form by the movement of grains lubricatred by interfacial water. This possibility have various consequences on chemical, mechanical or even possible astrobiological processes on Mars. Acknowledgment: This work was supported by the ESA ECS-project No. 98004 and the Pro Renovanda Cultura Hungariae Foundation.

  20. RAPID DETERMINATION OF {sup 210} PO IN WATER SAMPLES

    SciTech Connect

    Maxwell, S.

    2013-05-22

    A new rapid method for the determination of {sup 210}Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that can be used for emergency response or routine water analyses. If a radiological dispersive device (RDD) event or a radiological attack associated with drinking water supplies occurs, there will be an urgent need for rapid analyses of water samples, including drinking water, ground water and other water effluents. Current analytical methods for the assay of {sup 210}Po in water samples have typically involved spontaneous auto-deposition of {sup 210}Po onto silver or other metal disks followed by counting by alpha spectrometry. The auto-deposition times range from 90 minutes to 24 hours or more, at times with yields that may be less than desirable. If sample interferences are present, decreased yields and degraded alpha spectrums can occur due to unpredictable thickening in the deposited layer. Separation methods have focused on the use of Sr Resin, often in combination with 210Pb analysis. A new rapid method for {sup 210}Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that utilizes a rapid calcium phosphate co-precipitation method, separation using DGA Resin (N,N,N,N-tetraoctyldiglycolamide extractant-coated resin, Eichrom Technologies or Triskem-International), followed by rapid microprecipitation of {sup 210}Po using bismuth phosphate for counting by alpha spectrometry. This new method can be performed quickly with excellent removal of interferences, high chemical yields and very good alpha peak resolution, eliminating any potential problems with the alpha source preparation for emergency or routine samples. A rapid sequential separation method to separate {sup 210} Po and actinide isotopes was also developed. This new approach, rapid separation with DGA Resin plus microprecipitation for alpha source preparation, is a significant advance in radiochemistry for the rapid

  1. Determination of the Electronics Charge--Electrolysis of Water Method.

    ERIC Educational Resources Information Center

    Venkatachar, Arun C.

    1985-01-01

    Presents an alternative method for measuring the electronic charge using data from the electrolysis of acidified distilled water. The process (carried out in a commercially available electrolytic cell) has the advantage of short completion time so that students can determine electron charge and mass in one laboratory period. (DH)

  2. Radionuclide inventories for the F- and H-area seepage basin groundwater plumes

    SciTech Connect

    Hiergesell, Robert A; Kubilius, Walter P.

    2016-05-01

    Within the General Separations Areas (GSA) at the Savannah River Site (SRS), significant inventories of radionuclides exist within two major groundwater contamination plumes that are emanating from the F- and H-Area seepage basins. These radionuclides are moving slowly with groundwater migration, albeit more slowly due to interaction with the soil and aquifer matrix material. The purpose of this investigation is to quantify the activity of radionuclides associated with the pore water component of the groundwater plumes. The scope of this effort included evaluation of all groundwater sample analyses obtained from the wells that have been established by the Environmental Compliance & Area Completion Projects (EC&ACP) Department at SRS to monitor groundwater contamination emanating from the F- and H-Area Seepage Basins. Using this data, generalized groundwater plume maps for the radionuclides that occur in elevated concentrations (Am-241, Cm-243/244, Cs-137, I-129, Ni-63, Ra-226/228, Sr-90, Tc-99, U-233/234, U-235 and U-238) were generated and utilized to calculate both the volume of contaminated groundwater and the representative concentration of each radionuclide associated with different plume concentration zones.

  3. Methane seepage intensities traced by biomarker patterns in authigenic carbonates from the South China Sea

    NASA Astrophysics Data System (ADS)

    Guan, H.; Feng, D.

    2015-12-01

    Authigenic carbonate rocks from an active seep (Site F) at 1120 m water depth of the South China Sea (SCS) were studied using mineralogical and lipid biomarker analyses. Carbonate mineral compositions, in specific samples, were predominantly aragonite, high-Mg calcite (HMC), or a mixture of both. Abundant 13C-depleted lipid biomarkers (various isoprenoids) diagnostic for archaea provide evidence that anaerobic oxidation of methane (AOM) mediated by anaerobic methane oxidizing archaea (ANME) and their bacterial partners is the major process leading to formation of the carbonates. Nearly a pure suite of AOM biomarkers was preserved in aragonitic carbonate in which predominant consortia were most likely ANME-2/Desulfosarcina & Desulfococcus (DSS) assemblages and a mixture of ANME-2/DSS and ANME-1/DSS consortia in the mixed mineral sample, the predominant consortia are in good accordance with the point that the relative higher methane seepage intensity favors the precipitation of aragonite over HMC. In contrast, the completely different biomarker patterns in HMC sample were mainly composed terrestrial organic matter and marine Thaumarchaea, which most likely originally within sediments accompanied with high organic matter input and low methane supply. This environment is known to be favored for archaea of ANME-1 and precipitation of HMC. High concentrations of 13C-depleted hopanoids, including diplopterol, hopanoic acids and hopanols were observed in the aragonite sample that may be sourced by the intermittent presence of oxic conditions in an overall anoxic condition, which was possibly induced by changing seepage intensities.

  4. F-Area Seepage Basins groundwater monitoring report: First and second quarters 1993. Volume 1

    SciTech Connect

    Not Available

    1993-09-01

    During the first half of 1993, the groundwater at the F-Area Seepage Basins (FASB) was monitored in compliance with South Carolina Hazardous Waste Management Regulations, R61-79.265, Subpart F. Eighty-seven wells provided samples from the three hydrostratigraphic units that make up the uppermost aquifer beneath the FASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B Post-Closure Care Permit Application for the F-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control (SCDHEC) in December 1990. Beginning in the first quarter of 1993, the standard for comparison is the SCDHEC Groundwater Protection Standard (GWPS) specified in the approved F-Area Seepage Basins Part B Permit (November 1992). Currently and historically, gross alpha, nitrate, nonvolatile beta, and tritium are among the primary constituents to exceed standards. Numerous other radionuclides and hazardous constituents also exceeded the GWPS in the groundwater at the FASB during the first half of 1993, notably aluminum, iodine-129, technetium-99, and zinc. The elevated constituents are found primarily in Aquifer Zone IIB{sub 2} (Water Table) and Aquifer Zone IIB{sub 1}, (Barnwell/McBean) wells. However, several Aquifer Unit IIA (Congaree) wells also contain elevated levels of constituents.

  5. Determinations by Seasat of atmospheric water and synoptic fronts

    NASA Technical Reports Server (NTRS)

    Taylor, P. K.; Katsaros, K. B.; Lipes, R. G.

    1981-01-01

    It is shown by means of radiosonde data from the Joint Air-Sea Interaction (JASIN) experiment that the Seasat Scanning Multichannel Microwave Radiometer (SMMR) atmospheric water vapor distributions, taken over 600-km wide swaths with a resolution of 54 km, can be used to detect the position of atmospheric fronts in the lower troposphere. In addition to the fact that, unlike visible and IR radiometry, the SMMR determinations are not hampered by extensive cirrus or by a lack of frontal clouds, they use more channels, allowing better discrimination between the effects of liquid water, water vapor and sea state, and show improved spatial resolution. Data analysis results show that the SMMR atmospheric water vapor distributions have an accuracy comparable to that of in situ radiosonde measurements.

  6. Determination of minor elements in water by emission spectroscopy

    USGS Publications Warehouse

    Barnett, Paul R.; Mallory, E.C.

    1971-01-01

    With the emission spectrograph, the analyst is able to determine many minor elements simultaneously in water samples. Spectrographic methods differ chiefly in techniques of preconcentrating the elements. For waters with dissolved solids of less than 1,000 milligrams per liter, the method of evaporating to dryness and determining the elements in the dried residue is sensitive, precise, and reasonably accurate. The lower limits of detection vary with the quantity of dissolved solids. Twenty-four elements are determined by this method. For waters with more than 1,000 milligrams per liter of dissolved solids, it is necessary to separate the minor elements from the major constituents before spectrographically determining the former, in order to achieve adequate lower limits of detection. Such procedures generally require more time than the residue method. In the first of two such procedures given, 21 of the metallic elements are precipitated with thioacetamide prior to spectrographic determination. In an alternate procedure, 18 elements are precipitated quantitatively with complexing reagents 8-hydroxyquinoline, tannic acid, and thioanlide. This method is faster than the thioacetamide method, but at the sacrifice of some elements. A Fortran IV computer program for processing densitometric data is given in the section 'Computer Program.'

  7. Natural seepage of crude oil into the marine environment

    USGS Publications Warehouse

    Kvenvolden, K.A.; Cooper, C.K.

    2003-01-01

    Recent global estimates of crude-oil seepage rates suggest that about 47% of crude oil currently entering the marine environment is from natural seeps, whereas 53% results from leaks and spills during the extraction, transportation, refining, storage, and utilization of petroleum. The amount of natural crude-oil seepage is currently estimated to be 600,000 metric tons per year, with a range of uncertainty of 200,000 to 2,000,000 metric tons per year. Thus, natural oil seeps may be the single most important source of oil that enters the ocean, exceeding each of the various sources of crude oil that enters the ocean through its exploitation by humankind.

  8. Geological settings and seafloor morphodynamic evolution linked to methane seepage

    NASA Astrophysics Data System (ADS)

    Van Landeghem, Katrien J. J.; Niemann, Helge; Steinle, Lea I.; O'Reilly, Shane S.; Huws, Dei G.; Croker, Peter F.

    2015-08-01

    Methane seeps have been shown to be a powerful agent in modifying seabed morphology, amongst others by cementation processes such as the formation of methane-derived authigenic carbonates (MDACs). The cements stabilise mobile sediment particles and thereby promote the formation of edifices such as mounds on various scales. The release of methane from shallow subsurface sources, when concentrated in seeps, has proven hazardous to offshore construction activities. In this paper, methane cycling and MDAC precipitation is explored as a potential "finger on the pulse" for the recognition of shallow gas pockets and active gas seepage. This would provide a valuable planning tool for seabed engineering developments in areas of potential gas seepage. Measurements of methane concentrations in the Irish Sea are correlated with a unique record of longer-term morphological evolution (up to 11 years) of MDAC structures and subsurface geological settings which would favour the build-up of shallow gas. It was found that gas seepage activity associated with fault zones correlates with carbonate mound steepness. Cessation of gas seepage results in a relatively slow process of erosion and burial of the mounds, eventually producing a subdued carbonate mound morphology after several decades. The Quaternary glacial legacy equally seems to define the distribution and geometry of the MDAC structures. In this case, methane gas locally concentrated in sands and gravels capped by clayey glacial sediments may percolate upwards to the seafloor. A link between methane seeps and the formation of unusually large, trochoidally shaped sediment waves observed on continental shelves worldwide is deemed unlikely. However, the observations suggest that gas percolating through sediment waves may be capped by muddy sediments which have deposited on the sediment waves due to anoxic conditions or eroded from a neighbouring cliff. Other sediment waves in the Irish Sea were found to have a step

  9. Formation of a ravine network by seepage: coupling groundwater to sediment transport

    NASA Astrophysics Data System (ADS)

    Devauchelle, O.; Petroff, A. P.; Abrams, D. M.; Rothman, D.

    2009-12-01

    The formation of a ravine network by seepage of an aquifer can produce a highly complex pattern, even when sediment properties and precipitation are uniform. The steephead streams of the Apalachicola Bluffs and Ravines Preserve on the Florida Panhandle are a simple example of this type of landscape. We report comparisons of theoretical predictions for stream elevation profiles against field observations and analyses of high resolution LIDAR maps of this system. An initially flat seepage face is prone to develop channels due to water sapping, in a way that is similar to the fluid-dynamical interfacial instability that occurs when a non-viscous fluid is pushed into a viscous one. However there are significant differences. We investigate this mechanism by means of a two-dimensional model for the water table. The higher the curvature of a ravine tip, the more groundwater it attracts, causing tips to be unstable. However, ravines are stabilized by the requirement that all the sediment detached from the head must be removed by the stream. This analysis reproduces the 20 m spacing between nascent tips. Once a tip is formed, water flowing through it transports sediment removed from the tip, thus allowing the ravine to grow forward. Although the size and discharge of the streams vary considerably across the ravine networks, the hydraulic force exerted on the bed remains close to the minimum value required to move a sand grain. This equilibrium condition imposes a strong constraint on the stream elevation profile, thus coupling the sediment transport process to the groundwater flow. From this model we show that, in the neighborhood of the channel head, stream elevation profiles increase with the distance from the tip to the power two thirds. This result, supported by field data, relates the shape of the stream to the amount of water captured by its tip. In particular, sediment transport into the stream influences not only the landscape around the head, but also the ravine

  10. Determining the Most Appropriate Classification Methods for Water Quality

    NASA Astrophysics Data System (ADS)

    Gürsoy, Önder

    2016-10-01

    Assessing water resources’ quality and also monitoring them have attracted lots of attention in the recent years. Remote sensing has been growing widely in the last decade and its resources are very usable when it comes to water resources management. In this study, by using remote sensing technology, satellite images that have 350 to 1050 nanometres wavelength band sensors are used to determine the quality of the Kizilirmak River's water. Through the river's resources, ground based spectral measurements are made to identify the quality differences of the water at the test spots that have been determined before. In this context at Imranli, where the river contacts civilization for the first time, which is located in Sivas city of Turkey, samples are gathered in order to do ground based spectroradiometer measurements. These samples are gathered simultaneously with the image acquiring time of CHRIS Proba satellite. Spectral signatures that are obtained from ground measurements are used as reference data in order to classify CHRIS Proba satellite's hyperspectral images over the study area. Satellite images are classified based on Chemical Oxygen Demand (COD), Turbidity and Electrical Conductivity (EC) attributes. As a result, interpretations obtained from classified CHRIS Proba satellite hyperspectral images of the study area are presented. Spectras are readied for Matched Filtering and Spectral Angle Mapper methods for determining the best classification method.

  11. Experimental determination of cavitation thresholds in liquid water and mercury

    SciTech Connect

    Taleyarkhan, R.P.; West, C.D.; Moraga, F.

    1998-11-01

    An overview is provided on cavitation threshold measurement experiments for water and mercury. Various aspects to be considered that affect onset determination are discussed along with design specifications developed for construction of appropriate apparatus types. Both static and transient-cavitation effects were studied using radically different apparatus designs. Preliminary data are presented for cavitation thresholds for water and mercury over a range of temperatures in static and high-frequency environments. Implications and issues related to spallation neutron source target designs and operation are discussed.

  12. Brines in seepage channels as eluants for subsurface relict biomolecules on Mars?

    PubMed

    Wynn-Williams, D D; Cabrol, N A; Grin, E A; Haberle, R M; Stoker, C R

    2001-01-01

    Water, vital for life, not only maintains the integrity of structural and metabolic biomolecules, it also transports them in solution or colloidal suspension. Any flow of water through a dormant or fossilized microbial community elutes molecules that are potentially recognizable as biomarkers. We hypothesize that the surface seepage channels emanating from crater walls and cliffs in Mars Orbiter Camera images results from fluvial erosion of the regolith as low-temperature hypersaline brines. We propose that, if such flows passed through extensive subsurface catchments containing buried and fossilized remains of microbial communities from the wet Hesperian period of early Mars (approximately 3.5 Ga ago), they would have eluted and concentrated relict biomolecules and delivered them to the surface. Life-supporting low-temperature hypersaline brines in Antarctic desert habitats provide a terrestrial analog for such a scenario. As in the Antarctic, salts would likely have accumulated in water-filled depressions on Mars by seasonal influx and evaporation. Liquid water in the Antarctic cold desert analogs occurs at -80 degrees C in the interstices of shallow hypersaline soils and at -50 degrees C in salt-saturated ponds. Similarly, hypersaline brines on Mars could have freezing points depressed below -50 degrees C. The presence of hypersaline brines on Mars would have extended the amount of time during which life might have evolved. Phototrophic communities are especially important for the search for life because the distinctive structures and longevity of their pigments make excellent biomarkers. The surface seepage channels are therefore not only of geomorphological significance, but also provide potential repositories for biomolecules that could be accessed by landers.

  13. Brines in Seepage Channels as Eluants for Subsurface Relict Biomolecules on Mars?

    NASA Astrophysics Data System (ADS)

    Wynn-Williams, David D.; Cabrol, Nathalie A.; Grin, Edmond A.; Haberle, Robert M.; Stoker, Carol R.

    2001-06-01

    Water, vital for life, not only maintains the integrity of structural and metabolic biomolecules, it also transports them in solution or colloidal suspension. Any flow of water through a dormant or fossilized microbial community elutes molecules that are potentially recognizable as biomarkers. We hypothesize that the surface seepage channels emanating from crater walls and cliffs in Mars Orbiter Camera images result from fluvial erosion of the regolith as low-temperature hypersaline brines. We propose that, if such flows passed through extensive subsurface catchments containing buried and fossilized remains of microbial communities from the wet Hesperian period of early Mars (~3.5 Ga ago), they would have eluted and concentrated relict biomolecules and delive red them to the surface. Life-supporting low-temperature hypersaline brines in Antarctic desert habitats provide a terrestrial analog for such a scenario. As in the Antarctic, salts would likely have accumulated in water-filled depressions on Mars by seasonal influx and evaporation. Liquid water in the Antarctic cold desert analogs occurs at -80°C in the interstices of shallow hypersaline soils and at -50°C in salt-saturated ponds. Similarly, hypersaline brines on Mars could have freezing points depressed below -50°C. The presence of hypersaline brines on Mars would have extended the amount of time during which life might have evolved. Phototrophic communities are especially important for the search for life because the distinctive structures and longevity of their pigments make excellent biomarkers. The surface seepage channels are therefore not only of geomorphological significance, but also provide potential repositories for biomolecules that could be accessed by landers.

  14. Simultaneous extraction and determination of various pesticides in environmental waters.

    PubMed

    Zhang, Zulin; Lefebvre, Thibault; Kerr, Christine; Osprey, Mark

    2014-12-01

    A simple and rapid method was developed for the simultaneous analysis of nine different pesticides in water samples by gas chromatography with mass spectrometry. A number of parameters that may affect the recovery of pesticides, such as the type of solid-phase extraction cartridge, eluting solvent in single or combination and their volumes, and water pH value were investigated. It showed that three solid-phase extraction cartridges (Strata-X, Oasis HLB, and ENVI-18) produced the greatest recovery while ethyl acetate/dichloromethane/acetone (45:10:45, 12 mL) followed by dichloromethane (6 mL) was efficient in eluting target pesticides from solid-phase extraction cartridges. Different water pH values (4-9) did not show a significant effect on the pesticides recovery. The optimized method was verified by performing spiking experiments with a series of concentrations (0.002-10 μg/L) in waters, with good linearity, recovery, and reproducibility for most compounds. The limit of detection and limit of quantification of this optimized method were 0.01-2.01 and 0.02-6.71 ng/L, respectively, much lower than the European Union environmental quality standard for the pesticides (0.1 μg/L) in waters. The proposed method was further validated by participation in an interlaboratory trial. It was then subsequently applied to river waters from north-east Scotland, UK, for the determination of the target pesticides.

  15. Qualitative and quantitative determination of water in airborne particulate matter

    NASA Astrophysics Data System (ADS)

    Canepari, S.; Farao, C.; Marconi, E.; Giovannelli, C.; Perrino, C.

    2012-10-01

    This paper describes the optimization and validation of a new simple method for the quantitative determination of water in atmospheric particulate matter (PM). The analyses are performed by using a coulometric Karl-Fisher system equipped with a controlled heating device; different water contributions are separated by the application of an optimized thermal ramp (three heating steps: 50-120 °C, 120-180 °C, 180-250 °C). The analytical performance of the method was verified by using standard materials containing 5.55% and 1% by weight of water. The recovery was greater than 95%; the detection limit was about 20 μg. The method was then applied to NIST reference materials (NIST1649a, urban particulate matter) and to real PM10 samples collected in different geographical areas. In all cases the repeatability was satisfactory (10-15%). When analyzing the reference material, the separation of four different types of water was obtained. In real PM10 samples the amount of water and its thermal profile differed as a function of the chemical composition of the dust. Mass percentages of 3-4% of water were obtained in most samples, but values up to about 15% were reached in areas where the chemical composition of PM is dominated by secondary inorganic ions and organic matter. High percentages of water were also observed in areas where PM is characterized by the presence of desert dust. A possible identification of the quality of water released from the samples was tried by applying the method to some hygroscopic compounds that are likely contained in PM (pure SiO2, Al2O3, ammonium salts, carbohydrates and dicarboxylic acids) and by comparing the results with those obtained from field samples.

  16. Qualitative and quantitative determination of water in airborne particulate matter

    NASA Astrophysics Data System (ADS)

    Canepari, S.; Farao, C.; Marconi, E.; Giovannelli, C.; Perrino, C.

    2013-02-01

    This paper describes the optimization and validation of a new simple method for the quantitative determination of water in atmospheric particulate matter (PM). The analyses are performed by using a coulometric Karl-Fisher system equipped with a controlled heating device; different water contributions are separated by the application of an optimized thermal ramp (three heating steps: 50-120 °C, 120-180 °C, 180-250 °C). The analytical performance of the method was verified by using standard materials containing 5.55% and 1% by weight of water. The recovery was greater than 95%; the detection limit was about 20 μg. The method was then applied to NIST Reference Materials (NIST1649a, urban particulate matter) and to real PM10 samples collected in different geographical areas. In all cases the repeatability was satisfactory (10-15%). When analyzing the Reference Material, the separation of four different types of water was obtained. In real PM10 samples the amount of water and its thermal profile differed as a function of the chemical composition of the dust. Mass percentages of 3-4% of water were obtained in most samples, but values up to about 15% were reached in areas where the chemical composition of PM is dominated by secondary inorganic ions and organic matter. High percentages of water were also observed in areas where PM is characterized by the presence of desert dust. A possible identification of the quality of water released from the samples was tried by applying the method to some hygroscopic compounds that are likely contained in PM (pure SiO2, Al2O3, ammonium salts, carbohydrates and dicarboxylic acids) and by comparing the results with those obtained from field samples.

  17. Determination of water use in Rockford and Kankakee areas, Illinois

    USGS Publications Warehouse

    LaTour, John K.

    1991-01-01

    Amounts of water withdrawn, delivered, consumed, released, returned, and lost or gained during conveyance were determined for six communities--Rockford, Loves Park, North Park, Kankakee, Bourbonnais, and Bradley--served by the public-water systems in the Rockford and the Kankakee areas of Illinois. Water-use categories studied were commercial, industrial, domestic, and municipal uses; public supply; and sewage treatment. The availability and accuracy of water-use data are described, and water-use coefficients and methods of estimating water use are provided to improve the collection and the analysis of water-use information. Water-use data were obtained from all the water utilities and from 30 major water users in the Rockford and the Kankakee areas. Data were available for water withdrawals by water suppliers; deliveries by water suppliers to water users; returns by sewage-treatment plants and water users; releases by water users to sewers; and sewer-conveyance losses. Accuracy of the water-use data was determined from discharge measurements or reliability tests of water meters, or was estimated according to the completeness of the data. Accuracy of withdrawal and sewage-treatment-return data for the Rockford area and of withdrawal, delivery, industrial release, and sewage-treatment-return data for the Kankakee area was considered to be at least 90 percent. Where water-use data were inadequate or unavailable, various methods were used to estimate consumptive uses; releases; returns by commercial, domestic, and municipal users; and conveyance losses and gains. The methods focused on water budgeting to assure that water uses balanced. Consumptive uses were estimated by use of the consumption-budget method, the types-of-use method, consumptive-use ratios, the winter base-rate method, and the maximum lawn-watering method. The winter base-rate method provided the best domestic consumptive-use estimates, whose ratios (consumptive use from the winter base-rate method

  18. Platform and Environmental Effects on Above- and In-Water Determinations of Water-Leaving Radiances

    NASA Technical Reports Server (NTRS)

    Hooker, Stanford B.; Morel, Andre; McClain, Charles R. (Technical Monitor)

    2001-01-01

    A comparison of above- and in-water spectral measurements in Case-1 conditions showed the uncertainty in above-water determinations of water-leaving radiances depended on the pointing angle of the above-water instruments with respect to the side of the ship. Two above-water methods were used to create a diagnostic variable to quantify the presence of superstructure reflections which degraded the above-water intracomparisons of water-leaving radiances by 10.9-33.4% (for far-to-near viewing distances, respectively). The primary conclusions of the above- and in-water intercomparison of water-leaving radiances were as follows: a) the SeaWiFS 5% radiometric objective was achieved with the above-water approach, but reliably with only one method and only for about half the data; b) a decrease in water-leaving radiance values was seen in the presence of swell, although, wave crests were radiometrically brighter than the troughs; and c) standard band ratios used in ocean color algorithms remained severely affected, because of the relatively low signal and, thus, proportionally significant contamination at the 555nm wavelength.

  19. Xanthene dye chemiluminescence for determination of free chlorine in water

    SciTech Connect

    Yamada, M.; Hobo, T.; Suzuki, S.

    1988-10-01

    Preliminary investigations by a batch method are described for aiming at the flow determination of free chlorine in water with novel chemiluminescence (CL) detection. The CL originates from the reaction of xanthene dyes with free chlorine, Cl/sub 2/, HOCl, and OCl/sup -/. Through the measurements of CL decay curves, fundamental CL characteristics were explored from the analytical point of view. Among xanthene dyes tested, eosin Y, eosin B, pyronin B, and rhodamine 6G were found to be promising CL reagents with such sensitivity and selectivity that free chlorine can be readily determined in tap water. In particular, these CL systems have the special advantage of being insensitive to oxo acids of chlorine and chloramine. Recommended flow systems are proposed.

  20. Indirect spectrophotometric determination of traces of bromide in water

    USGS Publications Warehouse

    Fishman, M. J.; Skougstad, M.W.

    1963-01-01

    A rapid, accurate, and sensitive indirect spectrophotometric method for the determination of bromide in natural waters is based on the catalytic effect of bromide on the oxidation of iodine to iodate by potassium permanganate in sulfuric acid solution. The method is applicable to concentrations ranging from 1 to 100 ??g. of bromide per liter, but may be modified to extend the concentration range. Most ions commonly occurring in water do not interfere. The standard deviation is 2.9 at bromide concentrations of 100 ??g. per liter and less at lower concentrations. The determination of bromide in samples containing known added amounts gave values ranging from 99 to 105% of the concentration calculated to be present.

  1. Spectrophotometric determination of trace copper in water samples with thiomichlersketone

    NASA Astrophysics Data System (ADS)

    Fu, Dayou; Yuan, Dong

    2007-02-01

    A simple and sensitive spectrophotometric method for determination of trace copper in water samples is proposed. In the presence of pH 4.6 HAc-NaAc buffer solution and surfactant polyethylene octyl phenyl ether (OP) medium, copper reacts with thiomichlersketone (TMK) to form a stable 1:4 complex. The complex Cu(II)-TMK-OP shows maximum absorbance at 500 nm with a molar absorptivity value of 5.7 × 10 4 l mol -1 cm -1. Beer's law is obeyed for copper concentrations in the range of 0-15 μg/25 ml. The average recovery of copper is between 95.8 and 106%. The method has been applied for determination of trace copper in different water samples with satisfactory results.

  2. High Throughput Determination of VX in Drinking Water by ...

    EPA Pesticide Factsheets

    Methods Report This document provides the standard operating procedure for determination of the chemical warfare agent VX (O-Ethyl S-2-Diisopropylamino-Ethyl Methylphosphonothioate) in drinking water by isotope dilution liquid chromatography tandem mass spectrometer (LC/MS/MS). This method was adapted from one that was initially developed by the Centers for Disease Control and Prevention, in the National Center for Environmental Health for the determination and quantitation of VX in aqueous matrices. This method is designed to support site-specific cleanup goals of environmental remediation activities following a homeland security incident involving this analyte.

  3. Determination of metal ions in biological purification of waste waters

    SciTech Connect

    Tikhomirova, L.N.; Spiridonova, N.N.; Mandzhgaladze, I.D.

    1994-12-01

    Chromium, nickel, copper, zinc, and manganese were determined in active sludge extracted for utilization from sewage purification works in biological purification of waste waters. The measurements were carried out by the atomic absorption method and with Merck colorimetric kits for rapid determination of metal ions. The results obtained by the rapid colorimetric method agree fairly well with those obtained by the atomic absorption method, which makes it possible to recommend rapid colorimetric methods for routine analysis of biological objects for the content of ions of heavy metals.

  4. Sorption preconcentration of vanadium for its determination in sea water

    SciTech Connect

    Andreeva, I.Yu.; Lebedeva, L.I.; Izotova, Yu.A.; Danilova, E.Ya.

    1987-08-10

    This work is devoted to a study of the conditions of vanadium sorption by a fibrous sorbent with a view to evolving a procedure for its determination in sea water. The sorbent was the same as used by them earlier for molybdenum preconcentration. It is a fiber based on polyethylenepolyamine-modified polyacrylonitrile. The sorbent contained 80% tertiary and approx. = 20% primary and secondary amino groups. Static exchange capacity of the sorbent relative to HCl 2 mmole/g, swelling 34%, fiber diameter 0.016 mm. The vanadium content was determined photometrically using acidic chromium blue K.

  5. Factors Affecting the Temporal and Spatial Variability and Characteristics of Marine Hydrocarbon Seepage, Coal Oil Point, CA

    NASA Astrophysics Data System (ADS)

    del Sontro, T. S.; Leifer, I.; Luyendyk, B.

    2004-12-01

    , typically spanning several vents. Rising bubbles generate an upwelling flow of water that spins a turbine with an optical encoder on its axis. The encoders are connected to a multi-channel datalogger. Measurements are recorded in revolutions per second and converted to gas volume flux based on laboratory calibration. Spectra of the seepage time series showed the effect of external forcings, including swell and tides. Responses to external forcing factors, such as a 1% swell variation, differ between multiple tents. Seeps with a higher flux exhibit a smaller response than seeps with a lower flux. Flux variations between tents demonstrate the complexity of the underlying processes of gas, oil, and tar migration through an inter-connected subsurface fracture network.

  6. Recent Experimental Advances to Determine (noble) Gases in Waters

    NASA Astrophysics Data System (ADS)

    Kipfer, R.; Brennwald, M. S.; Huxol, S.; Mächler, L.; Maden, C.; Vogel, N.; Tomonaga, Y.

    2013-12-01

    In aquatic systems noble gases, radon, and bio-geochemically conservative transient trace gases (SF6, CFCs) are frequently applied to determine water residence times and to reconstruct past environmental and climatic conditions. Recent experimental breakthroughs now enable ● to apply the well-established concepts of terrestrial noble gas geochemistry in waters to the minute water amounts stored in sediment pore space and in fluid inclusions (A), ● to determine gas exchange processes on the bio-geochemical relevant time scales of minutes - hours (B), and ● to separate diffusive and advective gas transport in soil air (C). A. Noble-gas analysis in water samples (< 1 g) facilitates determining the solute transport in the pore space and identifying the origin of bio- and geogenic fluids in (un) consolidated sediments [1]. Advanced techniques that combine crushing and sieving speleothem samples in ultra-high-vacuum to a specific grain size allow to separate air and water-bearing fluid inclusions and thus enables noble-gas-based reconstruction of environmental conditions from water masses as small as 1mg [2]. B. The coupling of noble gas analysis with approaches of gas chromatography permits combined analysis of noble gases and other gases species (e.g., SF6, CFCs, O2, N2) from a single water sample. The new method substantially improves ground water dating by SF6 and CFCs as excess air is quantified from the same sample and hence can adequately be corrected for [3]. Portable membrane-inlet mass spectrometers enable the quasi-continuous and real-time analysis of noble gases and other dissolved gases directly in the field, allowing, for instance, quantification of O2 turnover rates on small time scales [4]. C. New technical developments perfect 222Rn analysis in water by the synchronous the determination of the short-lived 220Rn. The combined 220,222Rn analysis sheds light on the emanation behaviour of radon by identifying soil water content to be the crucial

  7. Seepage of methane at Jaco Scar, a slide caused by seamount subduction offshore Costa Rica

    NASA Astrophysics Data System (ADS)

    Mau, Susan; Rehder, Gregor; Sahling, Heiko; Schleicher, Tina; Linke, Peter

    2014-10-01

    Methane (CH4) concentrations and CH4 stable carbon isotopic composition () were investigated in the water column within Jaco Scar. It is one of several scars formed by massive slides resulting from the subduction of seamounts offshore Costa Rica, a process that can open up structural and stratigraphical pathways for migrating CH4. The release of large amounts of CH4 into the adjacent water column was discovered at the outcropping lowermost sedimentary sequence of the hanging wall in the northwest corner of Jaco Scar, where concentrations reached up to 1,500 nmol L-1. There CH4-rich fluids seeping from the sedimentary sequence stimulate both growth and activity of a dense chemosynthetic community. Additional point sources supplying CH4 at lower concentrations were identified in density layers above and below the main plume from light carbon isotope ratios. The injected CH4 is most likely a mixture of microbial and thermogenic CH4 as suggested by values between -50 and -62 ‰ Vienna Pee Dee Belemnite. This CH4 spreads along isopycnal surfaces throughout the whole area of the scar, and the concentrations decrease due to mixing with ocean water and microbial oxidation. The supply of CH4 appears to be persistent as repeatedly high CH4 concentrations were found within the scar over 6 years. The maximum CH4 concentration and average excess CH4 concentration at Jaco Scar indicate that CH4 seepage from scars might be as significant as seepage from other tectonic structures in the marine realm. Hence, taking into account the global abundance of scars, such structures might constitute a substantial, hitherto unconsidered contribution to natural CH4 sources at the seafloor.

  8. Investigating landfill-impacted groundwater seepage into headwater streams using stable carbon isotopes

    NASA Astrophysics Data System (ADS)

    Atekwana, E. A.; Krishnamurthy, R. V.

    2004-07-01

    The impact of landfill contaminated groundwater along a reach of a small stream adjacent to a municipal landfill was investigated using stable carbon isotopes as a tracer. Groundwater below the stream channel, groundwater seeping into the stream, groundwater from the stream banks and stream water were sampled and analysed for dissolved inorganic carbon (DIC) and the isotope ratio of DIC (13CDIC). Representative samples of groundwater seeping into the stream were collected using a device (a seepage well) specifically designed for collecting samples of groundwater seeping into shallow streams with soft sediments. The DIC and 13CDIC of water samples ranged from 52 to 205 mg C/L and -16.9 to +5.7 relative to VPDB standard, respectively. Groundwater from the stream bank adjacent to the landfill and some samples of groundwater below the stream channel and seepage into the stream showed evidence of 13C enriched DIC (δ13CDIC = -2.3 to +5.7), which we attribute to landfill impact. Stream water and groundwater from the stream bank opposite the landfill did not show evidence of landfill carbon (δ13CDIC = -10.0 to -16.9). A simple mixing model using DIC and δ13CDIC showed that groundwater below the stream and groundwater seeping into the stream could be described as a mixture of groundwater with a landfill carbon signature and uncontaminated groundwater. This study suggests that the hyporheic zone at the stream-groundwater interface probably was impacted by landfill contaminated groundwater and may have significant ecological implications for this ecotone.

  9. Radiometric method for determining solubility of organic solvents in water

    SciTech Connect

    Lo, J.M.; Tseng, C.L.; Yang, J.Y.

    1986-06-01

    Cobalt-60 labeled cobalt(III) pyrrolidinecarbodithioate (/sup 60/Co(PDC)/sub 3/) has a peculiar stability during storage in organic solvent and when its organic solution is shaken with an aqueous solution containing different acids or ions. Using these characteristics, the authors have attempted to use /sup 60/Co(PDC)/sub 3/ as a radioagent for determining solubilities of various organic solvents in water. The radioagent was first dissolved in the organic solvent under investigation before pure water was added. The solution mixture was shaken vigorously in order to let the organic phase contact with water sufficiently. Some of the organic solvent would dissolve in water after shaking, resulting in volume reduction of the organic phase. However, the radioagent was found not to accompany the organic solvent molecules going into water; i.e., all the radioactivity of /sup 60/Co(PDC)/sub 3/ would be retained in the organic phase. Solubility of the organic solvent in water therefore can be calculated from the value of the volume change of the organic phase divided by the water volume. Direct measurement of a small change in volume of organic phase with high accuracy is generally very difficult; alternatively, the authors have measured the specific activities of /sup 60/Co(PDC)/sub 3/ (cpm/mL) in the original and the final organic solutions, and the counting results were used to estimate the decrease in volume of the organic phase. Several commonly used organic solvents were selected to test the applicability of the proposed radiometric method. The solubilities of the organic solvents selected for this study range from very small values (10/sup -4/) to relatively large values (10/sup -2/), 6 references, 1 table.

  10. Behavioral Determinants of Switching to Arsenic-Safe Water Wells.

    PubMed

    George, Christine Marie; Inauen, Jennifer; Perin, Jamie; Tighe, Jennifer; Hasan, Khaled; Zheng, Yan

    2017-02-01

    More than 100 million people globally are estimated to be exposed to arsenic in drinking water that exceeds the World Health Organization guideline of 10 µg/L. In an effort to develop and test a low-cost sustainable approach for water arsenic testing in Bangladesh, we conducted a randomized controlled trial which found arsenic educational interventions when combined with fee-based water arsenic testing programs led to nearly all households buying an arsenic test for their drinking water sources (93%) compared with only 53% when fee-based arsenic testing alone was offered. The aim of the present study was to build on the findings of this trial by investigating prospectively the psychological factors that were most strongly associated with switching to arsenic-safe wells in response to these interventions. Our theoretical framework was the RANAS (risk, attitude, norm, ability, and self-regulation) model of behavior change. In the multivariate logistic regression model of 285 baseline unsafe well users, switching to an arsenic-safe water source was significantly associated with increased instrumental attitude (odds ratio [OR] = 9.12; 95% confidence interval [CI] = [1.85, 45.00]), descriptive norm (OR = 34.02; 95% CI = [6.11, 189.45]), coping planning (OR = 11.59; 95% CI = [3.82, 35.19]), and commitment (OR = 10.78; 95% CI = [2.33, 49.99]). In addition, each additional minute from the nearest arsenic-safe drinking water source reduced the odds of switching to an arsenic-safe well by more than 10% (OR = 0.89; 95% CI = [0.87, 0.92]). Future arsenic mitigation programs should target these behavioral determinants of switching to arsenic-safe water sources.

  11. Effect of downward seepage on turbulent flow characteristics and bed morphology around bridge piers

    NASA Astrophysics Data System (ADS)

    Chavan, Rutuja; Sharma, Anurag; Kumar, Bimlesh

    2017-01-01

    In this work, experimental investigations have been pursued to analyse the influence of downward seepage on the turbulent characteristics of flow and corresponding changes in vortex structure around circular bridge pier in alluvial channel. Experiments were conducted in sand bed channel with circular piers of different sizes for no seepage, 10% seepage and 20% seepage cases. The measurement of turbulent flow statistics such as velocity and Reynolds stresses is found to be negative within the scour hole at upstream of the pier whereas application of downward seepage retards the reversal of the flow causing a decrement in the velocity and Reynolds stresses. Higher Reynolds shear stress prevails at the downstream side because of the production of wake vortices. Contribution of all bursting events to the total Reynolds shear stress production has been observed to increase with downward seepage. The analysis of integral scale suggest that size of eddies increases with seepage, which is responsible for increase in particle mobility. Initially rate of scouring is more which abatements gradually with expanding time as well as with the increased of downward seepage. Presence of downward seepage reduces the depth and length of vortex and shifts towards downstream side of the pier.

  12. Effect of downward seepage on turbulent flow characteristics and bed morphology around bridge piers

    NASA Astrophysics Data System (ADS)

    Chavan, Rutuja; Sharma, Anurag; Kumar, Bimlesh

    2017-03-01

    In this work, experimental investigations have been pursued to analyse the influence of downward seepage on the turbulent characteristics of flow and corresponding changes in vortex structure around circular bridge pier in alluvial channel. Experiments were conducted in sand bed channel with circular piers of different sizes for no seepage, 10% seepage and 20% seepage cases. The measurement of turbulent flow statistics such as velocity and Reynolds stresses is found to be negative within the scour hole at upstream of the pier whereas application of downward seepage retards the reversal of the flow causing a decrement in the velocity and Reynolds stresses. Higher Reynolds shear stress prevails at the downstream side because of the production of wake vortices. Contribution of all bursting events to the total Reynolds shear stress production has been observed to increase with downward seepage. The analysis of integral scale suggest that size of eddies increases with seepage, which is responsible for increase in particle mobility. Initially rate of scouring is more which abatements gradually with expanding time as well as with the increased of downward seepage. Presence of downward seepage reduces the depth and length of vortex and shifts towards downstream side of the pier.

  13. Determining evaporation in the model of water transfer in soil

    NASA Astrophysics Data System (ADS)

    Zasukhin, Sergey

    2016-10-01

    In considered model a process of vertical water transfer in soil is described by one-dimensional nonlinear parabolic equation. Evaporation is one of most hard-determined component of the model. Determination of evaporation is formulated as an optimal control problem. In this problem, the objective function is mean-square deviation of soil moisture obtained by the model at various depths from some prescribed values. The sensitivity of soil moisture to changes of evaporation is estimated. These estimates allowed to determine an effective subsurface soil layer where it is advisable to compare calculated values of soil moisture with prescribed ones and to compute the objective function. This region definition has accelerated the convergence of numeric optimization process and has reduced the time of its execution.

  14. Seepage carbonate mounds in Cenozoic sedimentary sequences from the Las Minas Basin, SE Spain

    NASA Astrophysics Data System (ADS)

    Pozo, M.; Calvo, J. P.; Scopelliti, G.; González-Acebrón, L.

    2016-04-01

    A number of carbonate mounds composed of indurate, strongly folded and/or brecciated calcite and dolomite beds occur interstratified in Cenozoic sedimentary sequences from the Las Minas Basin. Part of the fabric of the rock forming the carbonate mounds is composed of laminated to banded dolostone similar to the host rock but showing contrasted lithification. Moreover, the carbonate deposits of the mounds display aggrading neomorphism of dolomite, partial replacement of dolomite by calcite, calcite cementation, and extensive silicification, locally resulting in box-work fabric. Eight main lithofacies were distinguished in the carbonate mound deposits. In some lithofacies, chert is present as both microcrystalline to fibro-radial quartz and opal, the latter occurring mainly as cement whereas the former replace the carbonate and infill voids. Yet one of the carbonate mounds shows distinctive petrography and geochemical features thus suggesting a distinctive growth pattern. The carbon isotope compositions of calcite from the mound samples range from - 11.56 to - 5.15 δ‰ whilst dolomite is depleted in 13C, with values of - 12.38 to 3.02 δ‰. Oxygen isotopic compositions vary from - 9.42 to - 4.64 δ‰ for calcite and between - 6.68 and 8.19 δ‰ for dolomite. Carbonate in the mounds shows significant enrichment in Co, Cr, Ni and Pb content, especially in the strongly deformed (F-2-2 lithofacies) and brecciated carbonate (F-4). The carbonate deposits show depletion in REE and Y in contrast to that determined in lutite. The formation of the carbonate mounds was related to local artesian seepage thermal water flows of moderate to relative high temperatures. Pressure differences between the low permeability host rock and the circulating fluids accounted for dilational fracturing and brecciation of the host sediment packages, which combined with precipitation of new carbonate and silica mineral phases. Locally, some carbonate mounds developed where groundwater

  15. Occurrence, distribution and prey items of juvenile marbled sole Pseudopleuronectes yokohamae around a submarine groundwater seepage on a tidal flat in southwestern Japan

    NASA Astrophysics Data System (ADS)

    Hata, Masaki; Sugimoto, Ryo; Hori, Masakazu; Tomiyama, Takeshi; Shoji, Jun

    2016-05-01

    Occurrence, distribution and prey items of juvenile marbled sole Pseudopleuronectes yokohamae were investigated around a submarine groundwater seepage on a tidal flat in southwestern Japan. Spatial distribution of radon-222 (222Rn) concentration in water showed more submarine groundwater seepage in the offshore area. The lower salinities at offshore sampling stations corresponded with the highest 222Rn concentrations. Juvenile marbled sole were collected from March through June with seasonal peak in April in 2013 and 2014. Mean abundance of juvenile marbled sole was highest at the second most offshore station where high submarine groundwater seepage was indicated. Major prey items in the stomachs of the marbled sole at the post-settlement stage (10-40 mm) were small crustaceans such as cumaceans and gammarids, which were partially replaced with polychaetes in larger juveniles (40-50 mm). Abundance of these major prey items was also higher at offshore stations. A negative correlation between gammarid abundance and salinity indicated a higher concentration of gammarids around the area of high submarine groundwater seepage, a pattern not observed for the other major prey organisms. Stable isotope analysis showed greater dependence of post-settlement stage marbled sole on the small crustaceans with low δ13C indicating that nutrients of terrestrial origin contribute to production of the juvenile marbled sole on the tidal flat.

  16. Determining water and nitrogen balances for beneficial management practices using lysimeters at Wagna test site (Austria).

    PubMed

    Klammler, Gernot; Fank, Johann

    2014-11-15

    The shallow Murtal aquifer south of Graz, Austria, provides easily withdrawable groundwater, which is supplied as drinking water without any chemical treatment. The aquifer is also used intensively by agriculture. Common agricultural management practices are the main source for diffuse nitrogen leaching and high groundwater nitrate concentrations. To safeguard the coexisting use of these two important resources, lysimeters are operated at the agricultural test site Wagna, Austria, and the influence of two beneficial management practices--low nitrogen input and organic farming--on nitrogen leaching towards groundwater is investigated. The technical lysimeter design as presented here consists of: (1) high-resolution weighing cells, (2) a suction controlled lower boundary condition for sucking off seepage water, thus emulating undisturbed field conditions, (3) comparative soil temperature, water content and matrix potential measurements inside and outside the lysimeter at different depths, (4) an installation of the lysimeters directly into test plots and (5) a removable upper lysimeter ring enabling machinery soil tillage. Our results indicate that oasis effects or fringe effects of the lysimeter cylinder on unsaturated water flow did not occur. Another lysimeter cultivated with lawn is operated for observing grass-reference evapotranspiration, which resulted in good agreement with calculated grass-reference evapotranspiration according to the FAO-Penman-Monteith method. We conclude that lysimeters installed at Wagna test site did not show any fringe effects and, thus, are appropriate tools for measuring water balance elements and nitrogen leaching of arable and grass land at point scale. Furthermore, our results for the period of 2005 to 2011 show that beneficial management practices reduced nitrate leaching and, hence, may allow for a sustainable coexistence of drinking water supply and agriculture in the Murtal aquifer.

  17. Hydrogeology, groundwater seepage, nitrate distribution, and flux at the Raleigh hydrologic research station, Wake County, North Carolina, 2005-2007

    USGS Publications Warehouse

    McSwain, Kristen Bukowski; Bolich, Richard E.; Chapman, Melinda J.

    2013-01-01

    gradients in the groundwater discharge area near the Neuse River were complex and were affected by fluctuations in river stage, with the exception of a well completed in a diabase dike. Water-quality data from the wells and surface-water sites at the RHRS were collected continuously as well as during periodic sampling events. Surface-water samples collected from a tributary were most similar in chemical composition to groundwater found in the regolith and transition zone. Nitrate (measured as nitrite plus nitrate, as nitrogen) concentrations in the sampled wells and tributary ranged from about 5 to more than 120 milligrams per liter as nitrogen. Waterborne continuous resistivity profiling conducted on the Neuse River in the area of the RHRS measured areas of low apparent resistivity that likely represent groundwater contaminated by high concentrations of nitrate. These areas were located on either side of a diabase dike and at the outfall of two unnamed tributaries. The diabase dike preferentially directed the discharge of groundwater to the Neuse River and may isolate groundwater movement laterally. Discrete temperature measurements made within the pore water beneath the Neuse River revealed seeps of colder groundwater discharging into warmer surface water near a diabase dike. Water-quality samples collected from the pore water beneath the Neuse River indicated that nitrate was present at concentrations as high as 80 milligrams per liter as nitrogen on the RHRS side of the river. The highest concentrations of nitrate were located within pore water collected from an area near a diabase dike that was identified as a suspected seepage area. Hydraulic head was measured and pore water samples were collected from two 140-centimeter-deep (55.1-inch-deep) multiport piezometers that were installed in bed sediments on opposite sides of a diabase dike. The concentration of nitrate in pore water at a suspected seepage area ranged from 42 to 82 milligrams per liter as nitrogen with a

  18. LPMLE3: A New Analytical Approach to Determine Vertical Groundwater-Surface Water Exchange Flux under Uncertainty and Heterogeneity

    NASA Astrophysics Data System (ADS)

    Schneidewind, Uwe; van Berkel, Matthijs; Anibas, Christian; Vandersteen, Gerd; Joris, Ingeborg; Seuntjens, Piet; Batelaan, Okke

    2015-04-01

    and parameter uncertainties. However, by assuming finite domains, thermal parameters only need to be considered locally constant, which is a more realistic assumption for a dynamic streambed. Flux results from the Slootbeek obtained with the LPMLE3 were compared to results from seepage meter measurements and those obtained with the LPML method (Vandersteen et al., 2014). For the Slootbeek we can show that during a three-week period in November 2012 the vertical flux varies between -186 mm/d (gaining stream conditions) and -300 mm/d with varying uncertainty. Hatch CE, Fisher AT, Revenaugh JS, Constantz J, Ruehl C. 2006. Quantifying surface water-groundwater interactions using time series analysis of streambed thermal records: Method development. Water Resour. Res., 42. DOI: 10.1029/2005wr004787. Keery J, Binley A, Crook N, Smith JWN. 2007. Temporal and spatial variability of groundwater-surface water fluxes: Development and application of an analytical method using temperature time series. J. Hydrol., 336: 1-16. DOI: 10.1016/j.jhydrol.2006.12.003. Vandersteen G*, Schneidewind U*, Anibas C*, Schmidt C, Seuntjens P, Batelaan O. 2014. Determining groundwater-surface water exchange from temperature time series: Combining a local polynomial method with a maximum likelihood estimator. Water Resour. Res. (accepted manuscript) DOI: 10.1002/2014wr015994. Wörman A, Riml J, Schmadel N, Neilson BT, Bottacin-Busolin A, Heavilin JE. 2012. Spectral scaling of heat fluxes in streambed sediments. Geophysical Research Letters, 39. DOI: 10.1029/2012gl053922.

  19. Uranium geochemistry in soil and groundwater at the F and H seepage basins

    SciTech Connect

    Serkiz, S.M.; Johnson, W.H.

    1994-09-01

    For 33 years, low activity liquid wastes from the chemical separation areas at the U.S. Department of Energy`s Savannah River Site were disposed of in unlined seepage basins. Soil and associated pore water samples of widely varying groundwater chemistries and contaminant concentrations were collected from the region downgradient of these basins using cone penetrometer technology. Analysis of samples using inductively coupled plasma - mass spectrometry has allowed the investigation of uranium partitioning between the aqueous phase and soil surfaces at this site. The distribution of uranium was examined with respect to the solution and soil chemistry (e.g., pH, redox potential, cation and contaminant concentration) and aqueous-phase chemical speciation modeling. The uranium soil source term at the F- and H-Area Seepage Basins (FHSB) is much smaller than has been used in previous modeling efforts. This should result in a much shorter remediation time and a greater effectiveness of a pump-and-treat design than previously predicted. Distribution coefficients at the (FHSB) were found to vary between 1.2 to 34,000 1 kg{sup {minus}1} for uranium. Differences in sorption of these elements can be explained primarily by changes in aqueous pH and the associated change in soil surface charge. Sorption models were fit directly to sorption isotherms from field samples. All models underestimated the fraction of uranium bound at low aqueous uranium concentrations. Linear models overestimated bound uranium at locations where the aqueous concentration was greater than 500 ppb. Mechanistic models provided a much better estimate of the bound uranium concentrations, especially at high aqueous concentrations. Since a large fraction of the uranium at the site is associated with the low-pH portion of the plume, consideration should be given to pumping water from the lowest pH portions of the plume in the F-Area.

  20. Determination of acetone and methyl ethyl ketone in water

    USGS Publications Warehouse

    Tai, D.Y.

    1978-01-01

    Analytical procedures for the determination of acetone and methyl ethyl ketone in water samples were developed. Concentrations in the milligram-per-liter range were determined by injecting an aqueous sample into the analysis system through an injection port, trapping the organics on Tenax-GC at room temperature, and thermally desorbing the organics into a gas chromatograph with a flame ionization detector for analysis. Concentrations in the microgram-per-liter range were determined by sweeping the headspace vapors over a water sample at 50C, trapping on Tenax-GC, and thermally desorbing the organics into the gas chromatograph. The precision for two operators of the milligram-per-liter concentration procedure, expressed as the coefficient of variation, was generally less than 2 percent for concentrations ranging from 16 to 160 milligrams per liter. The precision from two operators of the microgram-per-liter concentration procedure was between 2 and 4 percent for concentrations of 20 and 60 micrograms per liter. (Woodard-USGS)

  1. Rapid determination of the presence of enteric bacteria in water.

    PubMed

    Kenard, R P; Valentine, R S

    1974-03-01

    A rapid and sensitive method is described for the detection of bacteria in water and various other natural substrates by the isolation of specific bacteriophage. By the addition of large numbers of the organism in question to the sample, the presence of virulent bacteriophage can be demonstrated in as little as 6 to 8 h. Fecal coliform, total coliform, and total coliphage counts were determined for over 150 water samples from several geographical areas over a period of 2 years. Computer analysis of the data shows a high degree of correlation between fecal coliforms and the coliphage present in the samples. With a high correlation coefficient between fecal coliform and coliphage counts, predictions of the fecal coliforms may be made by enumeration of the phage.

  2. The determination of specific forms of aluminum in natural water

    USGS Publications Warehouse

    Barnes, R.B.

    1975-01-01

    A procedure for analysis and pretreatment of natural-water samples to determine very low concentrations of Al is described which distinguishes the rapidly reacting equilibrium species from the metastable or slowly reacting macro ions and colloidal suspended material. Aluminum is complexed with 8-hydroxyquinoline (oxine), pH is adjusted to 8.3 to minimize interferences, and the aluminum oxinate is extracted with methyl isobutyl ketone (MIBK) prior to analysis by atomic absorption. To determine equilibrium species only, the contact time between sample and 8-hydroxyquinoline is minimized. The Al may be extracted at the sample site with a minimum of equipment and the MIBK extract stored for several weeks prior to atomic absorption analysis. Data obtained from analyses of 39 natural groundwater samples indicate that filtration through a 0.1-??m pore size filter is not an adequate means of removing all insoluble and metastable Al species present, and extraction of Al immediately after collection is necessary if only dissolved and readily reactive species are to be determined. An average of 63% of the Al present in natural waters that had been filtered through 0.1-??m pore size filters was in the form of monomeric ions. The total Al concentration, which includes all forms that passed through a 0.1-??m pore size filter, ranged 2-70 ??g/l. The concentration of Al in the form of monomeric ions ranged from below detection to 57 ??g/l. Most of the natural water samples used in this study were collected from thermal springs and oil wells. ?? 1975.

  3. Seepage weathering impacts on erosivity of arid stream banks: A new conceptual model

    NASA Astrophysics Data System (ADS)

    Nachshon, Uri

    2016-05-01

    Field observations have indicated the formation of horizontal, pipe shape cavities, along gully and dry stream channel banks in the semi-arid region of the northern Negev Desert, Israel. Piping is a well-known phenomenon in humid regions due to subsurface water flow and seepage weathering. However, in dry environments where rain events are scarce and subsurface water flow is rare, it is proposed here that capillary flow of saline water in the vadose zone leads to similar processes. It is suggested that where saline and shallow ground water persists, capillary flow may result in salt accumulation and precipitation at the top of the capillary fringe, consequently rendering this zone to be more susceptible to erosion. A conceptual model is presented and field observations, laboratory experiments, and a physically-based model are used to prove the feasibility of the proposed conceptual model and to explain why salts accumulate at the top of the capillary fringe, even though evaporation acts all along the vertical stream channel or gully banks. It is suggested that the low evaporative flux, in comparison to the liquid water flux, disables salt accumulation along the profile to the top of the capillary fringe where the liquid water flux is minimal. The presented findings strengthen the conceptual model, but thorough field studies are needed to estimate the impact of the proposed mechanism on erosion processes on a field scale.

  4. Groundwater and surface-water interactions and impacts of human activities in the Hailiutu catchment, northwest China

    NASA Astrophysics Data System (ADS)

    Yang, Zhi; Zhou, Yangxiao; Wenninger, Jochen; Uhlenbrook, Stefan; Wang, Xusheng; Wan, Li

    2017-02-01

    The interactions between groundwater and surface water have been significantly affected by human activities in the semi-arid Hailiutu catchment, northwest China. Several methods were used to investigate the spatial and temporal interactions between groundwater and surface water. Isotopic and chemical analyses of water samples determined that groundwater discharges to the Hailiutu River, and mass balance equations were employed to estimate groundwater seepage rates along the river using chemical profiles. The hydrograph separation method was used to estimate temporal variations of groundwater discharges to the river. A numerical groundwater model was constructed to simulate groundwater discharges along the river and to analyze effects of water use in the catchment. The simulated seepage rates along the river compare reasonably well with the seepage estimates derived from a chemical profile in 2012. The impacts of human activities (river-water diversion and groundwater abstraction) on the river discharge were analyzed by calculating the differences between the simulated natural groundwater discharge and the measured river discharge. Water use associated with the Hailiutu River increased from 1986 to 1991, reached its highest level from 1992 to 2000, and decreased from 2001 onwards. The reduction of river discharge might have negative impacts on the riparian ecosystem and the water availability for downstream users. The interactions between groundwater and surface water as well as the consequences of human activities should be taken into account when implementing sustainable water resources management in the Hailiutu catchment.

  5. Determination of tributyltin in whole water matrices under the European Water Framework Directive.

    PubMed

    Richter, Janine; Fettig, Ina; Philipp, Rosemarie; Jakubowski, Norbert; Panne, Ulrich; Fisicaro, Paola; Alasonati, Enrica

    2016-08-12

    Monitoring of water quality is important to control water pollution. Contamination of the aquatic system has a large effect on human health and the environment. Under the European Water Framework Directive (WFD) 2000/60/EC and the related directive on environmental quality standards (EQS) in the field of water policy 2008/105/EC, the need for sensitive reference methods was highlighted. Since tributyltin (TBT) is one of the WFD listed priority substances a method was developed which is capable to qualify and quantify the pollutant at the required low WFD EQS of 0.2ngL(-1) in whole water bodies, i.e. in non-filtered water samples with dissolved organic carbon and suspended particulate matter. Therefore special attention was paid on the interaction of TBT with the suspended particulate matter and humic substances to obtain a complete representation of the pollution in surface waters. Different water samples were investigated varying the content of organic dissolved and suspended matter. Quantification was performed using species-specific isotope dilution (SSID) and gas chromatography with inductively coupled plasma mass spectrometry (GC-ICP-MS). Different sample treatment strategies were evaluated and compared. The process of internal standard addition was investigated and optimized, hence the equilibrium between internal standards and matrix is of primary importance to perform accurate SSID. Samples spiked at EQS level were analyzed with a recovery between 95 and 105 %. Additionally real surface water samples were investigated and the TBT concentration for the whole water body was determined and compared with conventional routine analysis method.

  6. Rapid determination of total trihalomethanes index in drinking water.

    PubMed

    Serrano, A; Gallego, M

    2007-06-22

    A method for the rapid determination of total trihalomethanes (THMs) index in drinking water has been developed by using a headspace-mass spectrometry (HS-MS) system and partial least squares (PLS) multivariate regression approach. Due to the presence of residual amounts of chlorine and organic matter in the drinking water, the use of a quenching reagent in order to avoid THM generation during the sample manipulation is necessary. The optimization experiments revealed that ascorbic acid was the best quenching reagent compared with sodium thiosulfate and ammonium sulfate. The use of a classification chemometric technique as soft independent modeling of class analogy before the PLS regression improved the results obtained in the prediction of the total THMs index, lowering the relative standard error of prediction (RSEP) from 11.4% to lower than 6.0%. The results obtained by the proposed HS-MS method were compared with those provided by a conventional chromatographic method after analyzing 20 real drinking water samples. A good agreement in the results was observed and no systematic differences were found, which corroborates the good performance of the proposed method.

  7. Optimal Parameter Determination for Tritiated Water Storage in Polyacrylic Networks

    SciTech Connect

    Postolache, C.; Matei, Lidia; Georgescu, Rodica; Ionita, Gh.

    2005-07-15

    Due to the remarkable capacity of water retaining, croslinked polyacrylic acids (PAA) represent an interesting alternative for tritiated water trapping. The study was developed on radiolytical processes in PAA:HTO systems derivated from irradiation of polymeric network by disintegration of tritium atoms from HTO. The aim of these studies is the identification of polymeric structures and optimal storage conditions.Sol and gel fractions were determinated by radiometrical methods using PAA labeled with 14-C at carboxylic groups and T at main chains of the polymer. Simulation of radiolytical processes was realized using {gamma} radiation field emitted by a irradiation source of 60-Co which ensures a maximum of absorbed dose rate of 3 kGy/h. Self-radiolytical effects were investigated using labeled PAA in HTO with great radioactive concentration (37-185 GBq/mL). The experiment suggests as optimum for HTO storage as tritium liquid wastes a 1:30 PAA:HTO swelling degree at 18.5-37 MBqL. HTO radioactive concentration.RES studies of radiolytical processes were also realized on dry polyacrylic acid (PAA) and polyacrylic based hydrogels irradiated and determined at 77 K. In the study we observed the effect of swelling capacity of hydrogel o the formation of free radicals.

  8. Water budget determination for Northern groundwater dependent lakes using stable isotopes of water

    NASA Astrophysics Data System (ADS)

    Isokangas, Elina; Rossi, Pekka; Ronkanen, Anna-Kaisa; Kløve, Bjørn

    2013-04-01

    Understanding groundwater - surface water interaction is crucial in numerous water resources management problems. Stable isotopes of water can bring understanding of this interaction especially in catchment scale questions. In this study stable isotopes were used in a Finnish esker aquifer (Lat 64.58° , Lon 26.50° ) where groundwater dependent lakes have suffered from seasonal water level declines. Esker aquifers are the main groundwater reserves in Finland used in water abstraction. In order to determine how hydrology of the lakes is dependent on groundwater, the isotopic composition of oxygen and hydrogen was studied from 36 sampling points during years 2010 to 2012. Samples were taken from 13 groundwater pipes, 11 lakes and 11 streams during winter, spring, summer and autumn. Additionally local precipitation was sampled. The CRDS-method (Picarro L2120-i analyzer) was used to analyze δ18O- and δ2H-values. The data from the study was used to define the Local Meteoric Water Line of the site (δ2H = 7.60 δ18O + 6.70) and the groundwater line of the esker aquifer (δ2H = 7.59 δ18O + 4.79). The groundwater line of the esker aquifer differs from the groundwater line of Finnish groundwaters (δ2H = 8.51 δ18O + 16.65) based on previous studies. This emphasizes the importance of using local isotopic values when stable isotopes of water are used in hydrological studies. Furthermore, the isotopic compositions of the examined lakes differed enough from the isotopic composition of the local groundwater to separate groundwater component in the lake hydrology. The results also verified that evaporation from lakes in Northern Finland can be high enough to utilize isotopic method for determination of groundwater and surface water interactions.

  9. Physical and bio-chemical mass-balance model around seafloor cold seepages

    NASA Astrophysics Data System (ADS)

    Yamazaki, T.; Takeuchi, R.; Monoe, D.; Oomi, T.; Nakata, K.; Fukushima, T.

    2007-12-01

    Natural cold seepages are characterized as rapid upward transports of methane from deeper part of geological structures to the seafloors. Prior to reach the seafloors, when methane meets downwards diffusing seawater sulfate, it is oxidized anaerobically by a consortium of microorganisms that use sulfate as an oxidant, producing sulfide. The anaerobic oxidation of methane and anaerobic sulfate reduction are clarified as a coupled biological activity. A significant portion of the bicarbonate produced after the sulfate reduction as authigenic carbonate, mainly aragonite and high-Mg calcite, near the seafloor. Where the methane fluxes are much, these anaerobic reactions occur just beneath the seafloor. There, usually sulfur oxidizing microorganisms are visible on the seafloor just above the coupled consortium of microorganisms. They are called bacterial mats. When the fluxes too much, direct methane bubbling occurs and chemosynthesis-immobilization communities such as tubeworms and clams distribute around the bubbling locations with the bacterial mats. The physical and bio-chemical mass-balance model around cold seepages on seafloor and in water column has been studied by the authors and some preliminary results were reported (Yamazaki et al., 2005 and 2006; Takeuchi et al., 2007). The approach is to analyze the existing field observation and numerical modeling studies of cold seepages and to create a new physical and bio-chemical mass-balance model in the environment. The model is separated into three parts. They are methane supply, seafloor ecosystem, and water column units. The seafloor ecosystem unit has been improved to analyze the unsteady formation processes of the ecosystem. The time dependencies of formations of the consortium of microorganisms (AOM), the chemosynthetic community, and bicarbonates examined with the improved model are introduced. After the bubbling from seafloor, the methane bubble jet blows up in the water column due to the buoyancy. Then the

  10. Heat as a tracer to determine streambed water exchanges

    USGS Publications Warehouse

    Constantz, J.

    2010-01-01

    This work reviews the use of heat as a tracer of shallow groundwater movement and describes current temperature-based approaches for estimating streambed water exchanges. Four common hydrologic conditions in stream channels are graphically depicted with the expected underlying streambed thermal responses, and techniques are discussed for installing and monitoring temperature and stage equipment for a range of hydrological environments. These techniques are divided into direct-measurement techniques in streams and streambeds, groundwater techniques relying on traditional observation wells, and remote sensing and other large-scale advanced temperatureacquisition techniques. A review of relevant literature suggests researchers often graphically visualize temperature data to enhance conceptual models of heat and water flow in the near-stream environment and to determine site-specific approaches of data analysis. Common visualizations of stream and streambed temperature patterns include thermographs, temperature envelopes, and one-, two-, and three-dimensional temperature contour plots. Heat and water transport governing equations are presented for the case of transport in streambeds, followed by methods of streambed data analysis, including simple heat-pulse arrival time and heat-loss procedures, analytical and time series solutions, and heat and water transport simulation models. A series of applications of these methods are presented for a variety of stream settings ranging from arid to continental climates. Progressive successes to quantify both streambed fluxes and the spatial extent of streambeds indicate heat-tracing tools help define the streambed as a spatially distinct field (analogous to soil science), rather than simply the lower boundary in stream research or an amorphous zone beneath the stream channel.

  11. The determinants of thermal comfort in cool water.

    PubMed

    Guéritée, J; House, J R; Redortier, B; Tipton, M J

    2015-10-01

    Water-based activities may result in the loss of thermal comfort (TC). We hypothesized that in cooling water, the hands and feet would be responsible. Supine immersions were conducted in up to five clothing conditions (exposing various regions), as well as investigations to determine if a "reference" skin temperature (Tsk) distribution in thermoneutral air would help interpret our findings. After 10 min in 34.5 °C water, the temperature was decreased to 19.5 °C over 20 min; eight resting or exercising volunteers reported when they no longer felt comfortable and which region was responsible. TC, rectal temperature, and Tsk were measured. Rather than the extremities, the lower back and chest caused the loss of overall TC. At this point, mean (SD) chest Tsk was 3.3 (1.7) °C lower than the reference temperature (P = 0.005), and 3.8 (1.5) °C lower for the back (P = 0.002). Finger Tsk was 3.1 (2.7) °C higher than the reference temperature (P = 0.037). In cool and cooling water, hands and feet, already adapted to colder air temperatures, will not cause discomfort. Contrarily, more discomfort may arise from the chest and lower back, as these regions cool by more than normal. Thus, Tsk distribution in thermoneutral air may help understand variations in TC responses across the body.

  12. F-area seepage basins groundwater monitoring report. Volume 1. First and second quarters 1995

    SciTech Connect

    1995-09-01

    Groundwater at the F-Area Seepage Basins (FASB) is monitored in compliance with Module 111, Section C, of South Carolina Hazardous Waste Permit SCl-890-008-989, effective November 2, 1992. The monitoring well network is composed of 86 FSB wells and well HSB 85A. These wells are screened in the three hydrostratigraphic Units that make up the uppermost aquifer beneath the FASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B post-closure care permit application for the F-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control (SCDHEC) in December 1900. Data from 9 FSL wells are included in this report only to provide additional information for this area; the FSL wells are not part of Permit SCl-890-008-989. Monitoring results are compared to the SCDHEC Groundwater Protection Standard (GWPS), which is specified in the approved F-Area Seepage Basins Part B permit (November 1992). Historically and currently, gross alpha, nitrate, nonvolatile beta, and tritium are among the primary constituents to exceed standards. Numerous other radionuclides and hazardous constituents also exceeded the GWPS in the groundwater at the FASB during the first half of 1995, notably aluminum, iodine-129, pH, strontium-90, and zinc. The elevated constituents are found primarily in Aquifer Zone IIB{sub 2} (Water Table) and Aquifer Zone IIB{sub 1}, (Barnwell/McBean) wells. However, several Aquifer Unit IIA (Congaree) wells also contain elevated levels of constituents. Isoconcentration/isoactivity maps included in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units. Geologic cross sections indicate both the extent and depth of contamination of the primary contaminants in all of the hydrostratigraphic units during the first half of 1995.

  13. F-Area Seepage Basins groundwater monitoring report -- third and fourth quarters 1993. Volume 1

    SciTech Connect

    Butler, C.T.

    1994-03-01

    During the second half of 1993, the groundwater at the F-Area Seepage Basins (FASB) was monitored in compliance with Module 3, Section C, of South Carolina Hazardous Waste Permit SC1-890-008-989, effective November 2, 1992. The monitoring well network is composed of 87 FSB wells screened in the three hydrostratigraphic units that make up the uppermost aquifer beneath the FASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B post-closure care permit application for the F-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control (SCDHEC) in December 1990. Beginning in the first quarter of 1993, the standard for comparison became the SCDHEC Groundwater Protection Standard (GWPS) specified in the approved F-Area Seepage Basins Part B permit. Currently and historically, gross alpha, nitrate, nonvolatile beta, and tritium are among the primary constituents to exceed standards. Numerous other radionuclides and hazardous constituents also exceeded the GWPS in the groundwater at the FASB during the second half of 1993, notably aluminum, iodine-129, and zinc. The elevated constituents are found primarily in Aquifer Zone 2B{sub 2} and Aquifer Zone 2B{sub 1} wells. However, several Aquifer Unit 2A wells also contain elevated levels of constituents. Isoconcentration/isoactivity maps included in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units. Water-level maps indicate that the groundwater flow rates and directions at the FASB have remained relatively constant since the basins ceased to be active in 1988.

  14. Distributed optical fiber-based theoretical and empirical methods monitoring hydraulic engineering subjected to seepage velocity

    NASA Astrophysics Data System (ADS)

    Su, Huaizhi; Tian, Shiguang; Cui, Shusheng; Yang, Meng; Wen, Zhiping; Xie, Wei

    2016-09-01

    In order to systematically investigate the general principle and method of monitoring seepage velocity in the hydraulic engineering, the theoretical analysis and physical experiment were implemented based on distributed fiber-optic temperature sensing (DTS) technology. During the coupling influence analyses between seepage field and temperature field in the embankment dam or dike engineering, a simplified model was constructed to describe the coupling relationship of two fields. Different arrangement schemes of optical fiber and measuring approaches of temperature were applied on the model. The inversion analysis idea was further used. The theoretical method of monitoring seepage velocity in the hydraulic engineering was finally proposed. A new concept, namely the effective thermal conductivity, was proposed referring to the thermal conductivity coefficient in the transient hot-wire method. The influence of heat conduction and seepage could be well reflected by this new concept, which was proved to be a potential approach to develop an empirical method monitoring seepage velocity in the hydraulic engineering.

  15. Modeling of coupled heat transfer and reactive transport processesin porous media: Application to seepage studies at Yucca Mountain, Nevada

    SciTech Connect

    Mukhopadhyay, S.; Sonnenthal, E.L.; Spycher, N.

    2007-01-15

    When hot radioactive waste is placed in subsurface tunnels, a series of complex changes occurs in the surrounding medium. The water in the pore space of the medium undergoes vaporization and boiling. Subsequently, vapor migrates out of the matrix pore space, moving away from the tunnel through the permeable fracture network. This migration is propelled by buoyancy, by the increased vapor pressure caused by heating and boiling, and through local convection. In cooler regions, the vapor condenses on fracture walls, where it drains through the fracture network. Slow imbibition of water thereafter leads to gradual rewetting of the rock matrix. These thermal and hydrological processes also bring about chemical changes in the medium. Amorphous silica precipitates from boiling and evaporation, and calcite from heating and CO{sub 2} volatilization. The precipitation of amorphous silica, and to a much lesser extent calcite, results in long-term permeability reduction. Evaporative concentration also results in the precipitation of gypsum (or anhydrite), halite, fluorite and other salts. These evaporative minerals eventually redissolve after the boiling period is over, however, their precipitation results in a significant temporary decrease in permeability. Reduction of permeability is also associated with changes in fracture capillary characteristics. In short, the coupled thermal-hydrological-chemical (THC) processes dynamically alter the hydrological properties of the rock. A model based on the TOUGHREACT reactive transport software is presented here to investigate the impact of THC processes on flow near an emplacement tunnel at Yucca Mountain, Nevada. We show how transient changes in hydrological properties caused by THC processes often lead to local flow channeling and saturation increases above the tunnel. For models that include only permeability changes to fractures, such local flow channeling may lead to seepage relative to models where THC effects are ignored

  16. Modeling of coupled heat transfer and reactive transport processesin porous media: Application to seepage studies at Yucca Mountain, Nevada

    SciTech Connect

    Mukhopadhyay, Sumit; Sonnenthal, Eric L.; Spycher, Nicolas

    2007-01-15

    When hot radioactive waste is placed in subsurface tunnels, a series of complex changes occurs in the surrounding medium. The water in the pore space of the medium undergoes vaporization and boiling. Subsequently, vapor migrates out of the matrix pore space, moving away from the tunnel through the permeable fracture network. This migration is propelled by buoyancy, by the increased vapor pressure caused by heating and boiling, and through local convection. In cooler regions, the vapor condenses on fracture walls, where it drains through the fracture network. Slow imbibition of water thereafter leads to gradual rewetting of the rock matrix. These thermal and hydrological processes also bring about chemical changes in the medium. Amorphous silica precipitates from boiling and evaporation, and calcite from heating and CO2 volatilization. The precipitation of amorphous silica, and to a much lesser extent calcite, results in long-term permeability reduction. Evaporative concentration also results in the precipitation of gypsum (or anhydrite), halite, fluorite and other salts. These evaporative minerals eventually redissolve after the boiling period is over, however, their precipitation results in a significant temporary decrease in permeability. Reduction of permeability is also associated with changes in fracture capillary characteristics. In short, the coupled thermal-hydrological-chemical (THC) processes dynamically alter the hydrological properties of the rock. A model based on the TOUGHREACT reactive transport software is presented here to investigate the impact of THC processes on flow near an emplacement tunnel at Yucca Mountain, Nevada. We show how transient changes in hydrological properties caused by THC processes often lead to local flow channeling and saturation increases above the tunnel. For models that include only permeability changes to fractures, such local flow channeling may lead to seepage relative to models where THC effects are ignored. However

  17. [The determination of molecular sulphur in Matsesta mineral water and its analog Novonukutskaya mineral water].

    PubMed

    Khutorianskiĭ, V A; Smirnov, A I; Matveev, D A

    2014-01-01

    The method of microcolumn reversed phase high performance liquid chromatography (rp-HPLC) was employed to determine the content of elemental sulphur in mineral waters. The study envisaged the analysis of the samples of sulphide-containing mineral waters Novonukutskaya and Matsesta obtained by the solid phase extraction technique. Based on these data, the authors discuss the origin and the circulation of sulphur in the hydrogen sulphide sources. The elution conditions selected in this study ensured the high-resolution separation of the octasulphur peak from the peaks of allotropic components of the extract whereas the two-wave detection technique allowed to identify the peaks of molecular sulphur.

  18. Water Resources Data, New Mexico, Water Year 1992

    USGS Publications Warehouse

    Cruz, R.R.; DeWees, R.K.; Funderburg, D.E.; Lepp, R.L.; Ortiz, D.; Shaull, D.A.

    1993-01-01

    measurements. Also, 1 seepage investigation is published this year. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in New Mexico.

  19. Water required, water used, and potential water sources for rice irrigation, north coast of Puerto Rico

    USGS Publications Warehouse

    Roman-Mas, A. J.

    1988-01-01

    A 3-yr investigation was conducted to determine the water required and used (both consumed and applied) for irrigation in the rice-growing areas of Vega Baja, Manati, and Arecibo along the north coast. In addition, the investigation evaluated the water resources of each area with regard to the full development of rice farming areas. Based on experiments conducted at selected test farms, water required ranged from 3.13 to 5.25 acre-ft/acre/crop. The amount of water required varies with the wet and dry seasons. Rainfall was capable of supplying from 31 to 70% of the water required for the measured crop cycles. Statistical analyses demonstrated that as much as 95% of rainfall is potentially usable for rice irrigation. The amount of water consumed differed from the quantity required at selected test farms. The difference between the amount of water consumed and that required was due to unaccounted losses or gains, seepage to and from the irrigation and drainage canals, and lateral leakage through levees. Due to poor water-management practices, the amount of water applied to the farms was considerably larger than the sum of the water requirement and the unaccounted losses or gains. Rivers within the rice growing areas constitute the major water supply for rice irrigation. Full development of these areas will require more water than the rivers can supply. Efficient use of rainfall can significantly reduce the water demand from streamflow. The resulting water demand, however, would still be in excess of the amount available from streamflow. Groundwater development in the area is limited because of seawater intrusion in the aquifers underlying the rice-growing areas. Capture of seepage to the aquifers using wells located near streams, artificial recharge, and development of the deep artesian system can provide additional water for rice irrigation. (Author 's abstract)

  20. A microscale Kjeldahl nitrogen determination for environmental waters.

    PubMed

    Campins-Falco, P; Meseguer-Lloret, S; Climent-Santamaria, T; Molins-Legua, C

    2008-05-30

    A microscale Kjeldahl system has been designed which has been homemade reduced. The digestor unit of a macroKjeldahl system and a modified glassware microdistillation unit have been used. The optimal conditions for digestion and distillation have been established for ammonium and methylamine as model compound of organic amino nitrogen. The optimised procedure has been applied to the determination of Kjeldahl nitrogen in water samples. Recoveries near 100% and good precision have been achieved. This procedure combines nitrogen miniaturized system and the use of a selective ion electrode for ammonia detection. The analysis time was reduced 4.8 times and the analysis cost 6.6 times compared with classical procedure. The residues generated have been also markedly minimized. A preconcentration factor of 4 instead of 1.5 obtained by the macroscale design has been achieved.

  1. Azomethine H colorimetric method for determining dissolved boron in water

    USGS Publications Warehouse

    Spencer, R.R.; Erdmann, D.E.

    1979-01-01

    An automated colorimetric method for determining dissolved boron in water is described. The boron is complexed with azomethine H, which is readily available as the condensation product of H acid (8-amino-1-naphthol-3,6-disulfonic acid) and salicylaldehyde. The absorbance of the yellow complex formed is then measured colorimetrically at 410 nm. Interference effects from other dissolved species are minimized by the addition of diethylenetriaminepentaacetic acid (DTPA); however, iron, zinc, and bicarbonate interfere at concentrations above 400 ??g/L, 2000 ??g/L, and 200 mg/L, respectively. The bicarbonate interference can be eliminated by careful acidification of the sample with concentrated HCl to a pH between 5 and 6. Thirty samples per hour can be routinely analyzed over the range of from 10 to 400 ??g/L, boron.

  2. Voltammetric Determination of Ni and Co in Water Samples

    NASA Astrophysics Data System (ADS)

    Herrera-Melian, Jose Alberto; Dona-Rodriguez, Jose Miguel; Hernandez-Brito, Joaquin; Perez Pena, Jesus

    1997-12-01

    Stripping voltammetry has attracted considerable attention for the determination of trace and ultratrace metals. This is mainly due to its high sensitivity and low cost of instrumentation. In adsorptive stripping voltammetry an organometallic complex is formed by the addition of a suitable ligand to the sample. The complex is adsorbed onto the Hg-drop by the application of the proper adsorption potential (more positive than E1/2) and solution stirring. After an adsorption period a cathodic (negative going) potential scan is applied and the metal concentration is calculated by the standard addition method. Nickel is found in natural waters at nM levels and is closely related with phosphates and silicates. Cobalt is a component of vitamin B12 and occurs in natural waters at concentration about 0.1 nM. We propose the voltammetric analysis of these elements by adsorptive stripping voltammetry as an introductory laboratory experiment for advanced chemistry or for chemical or environmental engineering students. The experiment has been proven to be very suitable for the laboratory part of the instrumental analysis course at the University of Las Palmas de Gran Canaria (Spain). In general, about 70% of the students have obtained good agreement (less than 10% of difference) between their results and the expected ones. Two hours is enough for the overall instrumental performance and the preparation of Ni and Co standards.

  3. Micellar electrokinetic chromatographic determination of triazine herbicides in water samples.

    PubMed

    Li, Zhi; Zhang, Shuaihua; Yin, Xiaofang; Wang, Chun; Wang, Zhi

    2014-09-01

    Dispersive liquid-liquid microextraction combined with online sweeping preconcentration in micellar electrokinetic chromatography was developed for the simultaneous determination of five triazine herbicides (atrazine, simazine, propazine, prometon and simetryn) in water samples. Several experimental parameters affecting the extraction efficiencies such as the type and volume of both the extraction and dispersive solvents, the addition of salt to sample solution, the extraction time and the pH of the sample solution were investigated. Under optimum conditions, the linearity of the method was good in the range from 0.33 to 20 ng mL(-1) for simazine, propazine, atrazine and simetryn, and from 0.17 to 20 ng mL(-1) for prometon, respectively. The sensitivity enrichment factors were in the range from 1750 to 2100, depending on the compound. The limit of detection (S/N = 3) ranged from 0.05 to 0.10 ng mL(-1). The developed method was successfully applied to the analysis of the five triazines in river, ground and well waters.

  4. Landscape characteristics impacts on water quality of urban lowland catchments: monitoring the Amsterdam city area

    NASA Astrophysics Data System (ADS)

    Yu, Liang; van der Vlugt, Corné; Rozemeijer, Joachim; Broers, Hans Peter; van Breukelen, Boris; Ouboter, Maarten; Stuyfzand, Pieter

    2015-04-01

    In Dutch lowland polder systems, groundwater quality significantly contributes to surface water quality. This process is influenced by landscape characteristics such as topography, geology, and land use types. In this study, 23 variables were selected for 144 polder catchments, including groundwater and surface water solute concentrations (TN, TP, NH4+, NO3-, HCO3-, SO42-, Ca2+, Cl-), seepage rate in mm per year, elevation, paved area percentage, surface water area percentage, and soil types (calcite, humus and lutum percentage). The spatial patters in groundwater and surface water quality can largely be explained by groundwater seepage rates in polders and partly by artificial redistribution of water via the regional surface water system. High correlations (R2 up to 0.66) between solutes in groundwater and surface water revealed their probable interaction. This was further supported by results from principal component analysis (PCA) and linear regression. The PCA distinguished four factors that were related to a fresh groundwater factor, seepage rate factor, brackish groundwater factor and clay soil factor. Nutrients (TP, TN, NH4+ and NO3-) and SO42- in surface water bodies are mainly determined by groundwater quality combined with seepage rate, which is negatively related to surface water area percentage and elevation of the catchment. This pattern is more obvious in deep urban lowland catchments. Relatively high NO3- loads more tend to appear in catchments with high humus, but low calcite percentage soil type on top, which was attributed to clay soil type that was expressed by calcite percentage in our regression. Different from nitrogen contained solutes, TP is more closely related to fresh groundwater quality than to seepage rate. Surface water Cl- concentration has a high relation with brackish groundwater. Due to the artificial regulation of flow direction, brackish inlet water from upstream highly influences the chloride load in surface water bodies

  5. Instream water use in the United States: water laws and methods for determining flow requirements

    USGS Publications Warehouse

    Lamb, Berton L.; Doerksen, Harvey R.

    1987-01-01

    the conterminous United States consists of about 12,000 miles of maintained waterways, over which about 500 million tons of cargo is carried each year (U.S. Army Corps of Engineers, 1988, p. 16). Although not so widely practiced in recent years, streams have been used to dispose of raw waste products from homes, communities, and factories. This use has been discouraged by law and public policy because of public health concerns and the damage it causes to the environment. Beginning in the mid-1960's, other instream uses gained new prominence in the water-resources arena-the assertion of a legal right to a free-flowing stream for biological, recreational, and esthetic purposes. These uses themselves, however, are not new. Riverine habitat always has produced fish, and the beauty of flowing water always has evoked a strong sense of esthetic appreciation. What is new is the emerging legitimacy and awareness of these noneconomic uses under State and Federal laws and regulations. In the past, environmental uses of flowing water were ignored, for the most part, under a long-standing legal tradition that favored offstream uses and certain instream uses that had a strong economic basis. The history of instream-flow policy debate really concerns those recently recognized types of interim uses. Although the more transitional water uses have been protected by law, the recognition of other in stream uses has resulted in substantial changes in State water laws. Although methods for determining the volume of water needed for most traditional water uses are relatively straight-forward and well-established, methods for determining water requirements for the in stream uses have been developed only recently and are continuing to evolve. Water laws that have favored the more traditional water uses, the inherent nature of conflict between instream and offstream water uses, and the special kinds of technological and philosophical problems posed by the "newer" types of instream uses are

  6. Electromembrane extraction for the determination of parabens in water samples.

    PubMed

    Villar-Navarro, Mercedes; Moreno-Carballo, María Del Carmen; Fernández-Torres, Rut; Callejón-Mochón, Manuel; Bello-López, Miguel Ángel

    2016-02-01

    To our knowledge, for the first time an electromembrane extraction combined with a high-performance liquid chromatography procedure using diode-array detection has been developed for the determination of five of the most widely used parabens: ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, isobutyl 4-hydroxybenzoate, and benzyl 4-hydroxybenzoate. Parabens were extracted from pH 4 aqueous sample solutions with use of an Accurel® S6/2 polypropylene hollow fiber that supports a liquid membrane of 1-octanol to a pH 12 aqueous acceptor solution placed inside the lumen of the hollow fiber. An electric current of 30 V was applied over the supported liquid membrane by means of platinum wires placed in the donor and acceptor phases. Parabens were extracted in 40 min with enrichment factors in the 30-49 range. The procedure has detection limits between 0.98 and 1.43 μg L(-1). The method was applied to the determination of parabens in surface environmental waters with excellent results.

  7. Rapid screening of triazines and quantitative determination in drinking water.

    PubMed

    Hamada, Mazen; Wintersteiger, Reinhold

    2002-01-01

    A sensitive, rapid and inexpensive analysis method has been developed for the triazines most frequently used in Palestine; the method includes fluorodensitometric screening and densitometric determination of the individual substances. Terbutryn as a model substance was derivatized with dansyl chloride in sodium hydrogen-carbonate or phosphate buffer solution to yield a green-blue fluorescent compound. Derivatization occurred at 120 degrees C within maximum of 10-min reaction time. The fluorescent compound formed was separated from excess reagent and other by-products on silica gel TLC plates and was then determined fluorodensitometrically. A linearity range between 20 and 1200 pg/spot was achieved. The method was also applied to other triazine herbicides such as ametryn, atrazine, propazine, terbuthylazine and simazine. Drinking water samples spiked with triazines were extracted using RP-C18 polar plus cartridges, and the extract could be then dansylated as a total. Recoveries were between 88% and 95%; the detection limit was 10 pg/spot and could be further improved to 2 pg/spot by a dipping solution. For quantification, each of the six triazines can be separated on one of three different stationary phases after solid phase extraction and measured densitometrically. The LOD for each individual triazine was 100 ng/l.

  8. 18 CFR 430.7 - Determination of protected areas and restriction on water use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Determination of protected areas and restriction on water use. 430.7 Section 430.7 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION SPECIAL REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.7 Determination of protected areas...

  9. 18 CFR 430.7 - Determination of protected areas and restriction on water use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Determination of protected areas and restriction on water use. 430.7 Section 430.7 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION SPECIAL REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.7 Determination of protected areas...

  10. 43 CFR 418.10 - Determining the amount of water duty to be delivered.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Determining the amount of water duty to be..., NEVADA Conditions of Water Delivery § 418.10 Determining the amount of water duty to be delivered. (a) Eligible land may receive no more than the amount of water in acre-feet per year established as...

  11. 43 CFR 418.10 - Determining the amount of water duty to be delivered.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Determining the amount of water duty to be..., NEVADA Conditions of Water Delivery § 418.10 Determining the amount of water duty to be delivered. (a) Eligible land may receive no more than the amount of water in acre-feet per year established as...

  12. 43 CFR 418.10 - Determining the amount of water duty to be delivered.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Determining the amount of water duty to be..., NEVADA Conditions of Water Delivery § 418.10 Determining the amount of water duty to be delivered. (a) Eligible land may receive no more than the amount of water in acre-feet per year established as...

  13. 18 CFR 430.7 - Determination of protected areas and restriction on water use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Determination of protected areas and restriction on water use. In consideration of the foregoing facts and for... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Determination of protected areas and restriction on water use. 430.7 Section 430.7 Conservation of Power and Water...

  14. 18 CFR 430.7 - Determination of protected areas and restriction on water use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Determination of protected areas and restriction on water use. In consideration of the foregoing facts and for... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Determination of protected areas and restriction on water use. 430.7 Section 430.7 Conservation of Power and Water...

  15. Savannah River Laboratory Seepage Basins: Waste site assessment report

    SciTech Connect

    Haselow, J.S.; Looney, B.B.; Nichols, R.L.

    1989-09-05

    This Waste Site Assessment for the SRL Seepage Basins is the second in a series of documents being prepared to support development of an appropriate closure plan for these basins. The closure of these basins will be designed to provide protection to human health and the environment and to meet the provisions of the Consent Decree. A Technical Data Summary for these basins has already been submitted as part of the Consent Decree. This Site Assessment Report includes a waste site characterization, and a discussion of closure options for the basins. A closure option is recommended in this report, but details of the recommended closure are not provided in this report since they will be provided in a subsequent closure plan. The closure plan is the third document required under the Consent Decree. 18 refs., 16 figs., 10 tabs.

  16. Environmental information document: Savannah River Laboratory Seepage Basins

    SciTech Connect

    Fowler, B.F.; Looney, B.B.; Simmons, R.V.; Bledsoe, H.W.

    1987-03-01

    This document provides environmental information on postulated closure options for the Savannah River Laboratory Seepage Basins at the Savannah River Plant and was developed as background technical documentation for the Department of Energy`s proposed Environmental Impact Statement (EIS) on waste management activities for groundwater protection at the plant. The results of groundwater and atmospheric pathway analyses, accident analysis, and other environmental assessments discussed in this document are based upon a conservative analysis of all foreseeable scenarios as defined by the National Environmental Policy Act (CFR, 1986). The scenarios do not necessarily represent actual environmental conditions. This document is not meant to be used as a closure plan or other regulatory document to comply with required federal or state environmental regulations.

  17. Salt water and its relation to fresh ground water in Harris County, Texas

    USGS Publications Warehouse

    Winslow, Allen G.; Doyel, William Watson; Wood, L.A.

    1957-01-01

    Other less probable potential sources of salt-water contamination which are discussed include upward movement of salt water from below, vertical movement around salt domes or along faults, downward seepage from surface sources, and contamination through leaking wells.

  18. Massive asphalt deposits, oil seepage, and gas venting support abundant chemosynthetic communities at the Campeche Knolls, southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Sahling, Heiko; Borowski, Christian; Escobar-Briones, Elva; Gaytán-Caballero, Adriana; Hsu, Chieh-Wei; Loher, Markus; MacDonald, Ian; Marcon, Yann; Pape, Thomas; Römer, Miriam; Rubin-Blum, Maxim; Schubotz, Florence; Smrzka, Daniel; Wegener, Gunter; Bohrmann, Gerhard

    2016-08-01

    Hydrocarbon seepage is a widespread process at the continental margins of the Gulf of Mexico. We used a multidisciplinary approach, including multibeam mapping and visual seafloor observations with different underwater vehicles to study the extent and character of complex hydrocarbon seepage in the Bay of Campeche, southern Gulf of Mexico. Our observations showed that seafloor asphalt deposits previously only known from the Chapopote Knoll also occur at numerous other knolls and ridges in water depths from 1230 to 3150 m. In particular the deeper sites (Chapopopte and Mictlan knolls) were characterized by asphalt deposits accompanied by extrusion of liquid oil in form of whips or sheets, and in some places (Tsanyao Yang, Mictlan, and Chapopote knolls) by gas emission and the presence of gas hydrates in addition. Molecular and stable carbon isotopic compositions of gaseous hydrocarbons suggest their primarily thermogenic origin. Relatively fresh asphalt structures were settled by chemosynthetic communities including bacterial mats and vestimentiferan tube worms, whereas older flows appeared largely inert and devoid of corals and anemones at the deep sites. The gas hydrates at Tsanyao Yang and Mictlan Knolls were covered by a 5-to-10 cm-thick reaction zone composed of authigenic carbonates, detritus, and microbial mats, and were densely colonized by 1-2 m-long tube worms, bivalves, snails, and shrimps. This study increased knowledge on the occurrences and dimensions of asphalt fields and associated gas hydrates at the Campeche Knolls. The extent of all discovered seepage structure areas indicates that emission of complex hydrocarbons is a widespread, thus important feature of the southern Gulf of Mexico.

  19. Ecology and equity: key determinants of sustainable water security.

    PubMed

    Swaminathan, M S

    2001-01-01

    Trends in water consumption indicate that demand for water for household and industrial uses in developing countries could double as a proportion of total water demand in the next 25 years. Scope for expansion of water supply will, at the same time, be limited because development of irrigation and urban water supplies is becoming increasingly expensive, and often involves high costs in terms of environmental degradation and human resettlement. Without fundamental reform of water management, the rapid growth in urban water demand will require large transfers of water from irrigated agriculture, thereby threatening food security. Hence, water supply and demand should be managed in an integrated fashion, simultaneously considering all uses and sources. This will call for the establishment of community centred food and water security systems and national water trusts. Once such systems and Trusts are established there could be a legally binding Global Water Convention on the model of the Global Convention on Climate and Biodiversity. The details of such a Global Water Conventions can be finalized at one of the future Stockholm Water Symposia. There are uncommon opportunities today for a water-secure world through synergy between technology, public policy and peoples' participation.

  20. F-Area Seepage Basins groundwater monitoring report, Third quarter 1992

    SciTech Connect

    Thompson, C.Y.

    1992-12-01

    During third quarter 1992, the groundwater at the F-Area Seepage Basins (FASB) was monitored in compliance with South Carolina Hazardous Waste Management Regulations, R61-79.265, Subpart F. Eighty-five wells provided samples from the three separate hydrostratigraphic units that make up the uppermost aquifer beneath the FASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B Post-Closure Care Permit Application for the F-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control in December 1990. Historically, as well as currently, tritium, nitrate, lead, cadmium, and gross alpha are the primary constituents observed above the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater at the FASB. Nonvolatile beta has consistently exceeded its drinking water screening level. Other radionuclides and hazardous constituents also have exceeded the PDWS in the groundwater at the FASB. Isoconcentration maps included in this report indicate both the concentration and extent of the primary contaminants in each of the three hydrostratigraphic units. Water-level maps indicate that the groundwater flow rates and directions at the FASB have remained relatively constant since the basins ceased to be active in 1988.

  1. H-Area Seepage Basins groundwater monitoring report, third quarter 1992

    SciTech Connect

    Not Available

    1992-12-01

    During third quarter 1992, the groundwater at the H-Area Seepage Basins (HASB) was monitored in compliance with South Carolina Hazardous Waste Management Regulations, R61-79.265, Subpart F. One hundred thirty wells provided samples from the three separate hydrostratigraphic units that make up the uppermost aquifer beneath the HASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B Post-Closure Care Permit Application for the H-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control in December 1990. Historically, as well as currently, tritium, nitrate, mercury, and gross alpha have been the primary constituents observed above the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater at the HASB. Nonvolatile beta has consistently exceeded its drinking water screening level. Other radionuclides and hazardous constituents also have exceeded the PDWS in the groundwater at the HASB. Isoconcentration maps included in this report indicate both the concentration and extent of the primary contaminants in each of the three hydrostratigraphic units. Water-level maps indicate that the groundwater flow rates and directions at the HASB have remained relatively constant since the basins ceased to be active in 1988.

  2. Determination of soil–water sorption coefficients of volatile methylsiloxanes

    PubMed Central

    Kozerski, Gary E; Xu, Shihe; Miller, Julie; Durham, Jeremy

    2014-01-01

    The sorption behaviors of 4 cyclic and linear volatile methyl siloxane (VMS) compounds between water and organic matter in 3 United Kingdom soils were studied by a batch equilibrium method using13C-enriched sorbates. Sorption and desorption kinetics and isotherms were determined for octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), octamethyltrisiloxane (L3), and decamethyltetrasiloxane (L4). Concentrations of [13C]-VMS in the soil and aqueous phases were measured directly by extraction and gas chromatography–mass spectrometry techniques. All VMS compounds were sorbed rapidly, reaching constant distributions in all soils by 24 h. Desorption kinetics were very rapid, with reattainment of equilibrium within 1 h. In the main, linear isotherms were observed for aqueous concentrations at or below 4% of the solubility limits. The average sorption organic carbon partition coefficient (log KOC) values across soils were 4.23 for D4, 5.17 for D5, 4.32 for L3, and 5.13 for L4, with standard deviations of 0.09 to 0.34. Desorption KOC values were systematically greater by 0.1 log units to 0.3 log units. The linear isotherms and low variation in KOC values across soils suggested partitioning-dominated sorption of the VMS. Compared with traditional hydrophobic organic compounds, KOC values for the VMS compounds were significantly lower than expected on the basis of their octanol–water partition coefficients. A linear free energy relationship analysis showed that these differences could be rationalized quantitatively in terms of the inherent characteristics of the VMS compounds, combined with the differences in solvation properties of organic matter and octanol. Environ Toxicol Chem 2014; 33:1937–1945. PMID:24862578

  3. Probability distribution functions of turbulence in seepage-affected alluvial channel

    NASA Astrophysics Data System (ADS)

    Sharma, Anurag; Kumar, Bimlesh

    2017-02-01

    The present experimental study is carried out on the probability distribution functions (PDFs) of turbulent flow characteristics within near-bed-surface and away-from-bed surfaces for both no seepage and seepage flow. Laboratory experiments were conducted in the plane sand bed for no seepage (NS), 10% seepage (10%S) and 15% seepage (15%) cases. The experimental calculation of the PDFs of turbulent parameters such as Reynolds shear stress, velocity fluctuations, and bursting events is compared with theoretical expression obtained by Gram-Charlier (GC)-based exponential distribution. Experimental observations follow the computed PDF distributions for both no seepage and seepage cases. Jensen-Shannon divergence (JSD) method is used to measure the similarity between theoretical and experimental PDFs. The value of JSD for PDFs of velocity fluctuation lies between 0.0005 to 0.003 while the JSD value for PDFs of Reynolds shear stress varies between 0.001 to 0.006. Even with the application of seepage, the PDF distribution of bursting events, sweeps and ejections are well characterized by the exponential distribution of the GC series, except that a slight deflection of inward and outward interactions is observed which may be due to weaker events. The value of JSD for outward and inward interactions ranges from 0.0013 to 0.032, while the JSD value for sweep and ejection events varies between 0.0001 to 0.0025. The theoretical expression for the PDF of turbulent intensity is developed in the present study, which agrees well with the experimental observations and JSD lies between 0.007 and 0.015. The work presented is potentially applicable to the probability distribution of mobile-bed sediments in seepage-affected alluvial channels typically characterized by the various turbulent parameters. The purpose of PDF estimation from experimental data is that it provides a complete numerical description in the areas of turbulent flow either at a single or finite number of points.

  4. Determination of oil/water and octanol/water distribution coefficients from aqueous solutions from four fossil fuels. [MS thesis; in oil-water and octanol-water

    SciTech Connect

    Thomas, B.L.

    1984-07-01

    Liquid fossil fuels, both petroleum and synthetically derived oils, are exceedingly complex mixtures of thousands of components. The effect of many of these energy-related components on the environment is largely unknown. Octanol/water distribution coefficients relate both to toxicity and to the bioaccumulation potential of chemical components. Use of these partition data in conjunction with component concentrations in the oils in environmental models provides important information on the fate of fossil fuel components when released to the environment. Octanol/water distribution data are not available for many energy-related organic compounds, and those data that are available have been determined for individual components in simple, one-component octanol/water equilibrium mixtures. In this study, methods for determining many octanol/water distribution coefficients from aqueous extracts of oil products were developed. Sample aqueous mixtures were made by equilibrating liquid fossil fuels with distilled water. This approach has the advantage of detecting interactions between components of interest and other sample components. Compound types studied included phenols, nitrogen bases, hydrocarbons, sulfur heterocyclic compounds, and carboxylic acids. Octanol/water distribution coefficients that were determined in this study ranged from 9.12 for aniline to 67,600 for 1,2-dimethylnaphthalene. Within a compound type, distribution coefficients increased logarithmically with increasing alkyl substitution and molecular weight. Additionally, oil/water distribution data were determined for oil components. These data are useful in predicting maximum environmental concentrations in water columns. 96 references, 26 figures, and 40 tables.

  5. Results of a seepage investigation at Bear Creek Valley, Oak Ridge, Tennessee, January through September 1994

    USGS Publications Warehouse

    Robinson, J.A.; Johnson, G.C.

    1996-01-01

    A seepage investigation was conducted of 4,600 acres of Bear Creek Valley southwest of the Y-12 Plant, Oak Ridge, Tennessee, for the period of January through September 1994. The data were collected to help the Y-12 Environmental Restoration Program develop a better understanding of ground-water and surface-water interactions, recharge and discharge relations, and ground-water flow patterns. The project was divided into three phases: a reconnaissance and mapping of seeps, springs, and stream-measurment sites; a high base flow seepage investigation; and a low base flow seepage investigation. The reconnaissance was conducted from January 6 to March 1, 1994, to identify and map the locations of seeps, springs, and stream-measurement sites. A total of 701 sites were identified. They consisted of 382 stream- measurement sites, 265 seeps, 48 springs, and 6 wetlands. A global positioning system was used to locate 680 sites to within 3- to 5-meter accuracy. The high base flow seepage investigation was conducted from March 14 through March 19, 1994. Measurements were made at 579 of the 701 sites identified in the reconnaissance that still had flowing water. Flow rates ranged from less than 0.005 to 6.89 cubic feet per second for the streams, from less than 0.005 to 0.13 cubic foot per second for the seeps, and from less than 0.005 to 1 cubic foot per second for the springs. pH ranged from 5.0 to 8.4 for the streams, from 5.1 to 8.2 for the seeps, from 5.3 to 8.0 for the springs, and from 6.7 to 6.8 for the wetland sites. Specific conductance ranged from 16 to 1,670 microsiemens per centimeter for the streams, from 17 to 1,710 microsiemens per centimeter for the seeps, from 14 to 1,150 microsiemens per centimeter for the springs, and from 102 to 160 microsiemens per centimeter for the wetland sites. Temperature ranged from 4.5 to 16.0 degrees Celsius for the streams, from 5.0 to 21.0 degrees Celsius for the seeps, from 6.0 to 13.5 degrees Celsius for the springs, and from 13

  6. Factors Affecting Atrazine Concentration and Quantitative Determination in Chlorinated Water

    EPA Science Inventory

    Although the herbicide atrazine has been reported to not react measurably with free chlorine during drinking water treatment, this work demonstrates that at contact times consistent with drinking water distribution system residence times, a transformation of atrazine can be obser...

  7. Determining operating policies for a water resource system

    NASA Astrophysics Data System (ADS)

    Dagli, C. H.; Miles, J. F.

    1980-07-01

    The object of the study described in this paper was to find a method of determining operating policies for a set of four dams which are to be constructed on the Firat (Euphrates) River in Turkey. Each of the dams has an associated hydro-electric power plant, and there are requirements to supply water for irrigation, as well as maintaining river flows downstream of the dams into Syria and Iraq. The problem is thus complex and conventional stochastic models would entail an excessive amount of computation. Moreover, the set of feasible operating policies is so large that simulation cannot be considered a viable alternative. The method adopted might be described as adaptive planning (AP). At time l a forecast is made of the inflow values expected during the planning period and using these forecast values a deterministic model of the system is solved to obtain an operating policy for time l + 1. The forecast is updated and the model re-run at each successive time period to yield revised policies based on the latest available data. The solution obtained by this method for a five-year test period, using historical data, was within 0.4% of the optimal solution.

  8. Determining Water Content of Geologic Materials Using Reflectance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Milliken, R. E.; Mustard, J. F.

    2004-03-01

    TGA data and reflectance spectra are used to track changes in water absorptions as a function of absolute water content. Calculating band depth areas of absorptions in VIS-NIR data may prove useful for quantifying the water content of Mars' surface.

  9. Applications of spectroscopy to remote determination of water quality

    NASA Technical Reports Server (NTRS)

    Goldberg, M. C.; Weiner, E. R.

    1972-01-01

    The use of remote laser Raman and molecular spectroscopic techniques to measure water quality is examined. Measurements cover biological, chemical, and physical properties of the water. Experimental results show chemical properties are harder to obtain remotely than biological or physical properties and that molecular spectroscopy seems to be the best method for obtaining water quality data.

  10. Determinants of Water Permeability through Nanoscopic Hydrophilic Channels

    PubMed Central

    Portella, Guillem; de Groot, Bert L.

    2009-01-01

    Naturally occurring pores show a variety of polarities and sizes that are presumably directly linked to their biological function. Many biological channels are selective toward permeants similar or smaller in size than water molecules, and therefore their pores operate in the regime of single-file water pores. Intrinsic factors affecting water permeability through such pores include the channel-membrane match, the structural stability of the channel, the channel geometry and channel-water affinity. We present an extensive molecular dynamics study on the role of the channel geometry and polarity on the water osmotic and diffusive permeability coefficients. We show that the polarity of the naturally occurring peptidic channels is close to optimal for water permeation, and that the water mobility for a wide range of channel polarities is essentially length independent. By systematically varying the geometry and polarity of model hydrophilic pores, based on the fold of gramicidin A, the water density, occupancy, and permeability are studied. Our focus is on the characterization of the transition between different permeation regimes in terms of the structure of water in the pores, the average pore occupancy and the dynamics of the permeating water molecules. We show that a general relationship between osmotic and diffusive water permeability coefficients in the single-file regime accounts for the time averaged pore occupancy, and that the dynamics of the permeating water molecules through narrow non single file channels effectively behaves like independent single-file columns. PMID:19186131

  11. Determination of spectral signatures of substances in natural waters

    NASA Technical Reports Server (NTRS)

    Klemas, V.; Philpot, W. D.; Davis, G.

    1978-01-01

    Optical remote sensing of water pollution offers the possibility of fast, large scale coverage at a relatively low cost. The possibility of using the spectral characteristics of the upwelling light from water for the purpose of ocean water quality monitoring was explained. The work was broken into several broad tasks as follows: (1) definition of a remotely measured spectral signature of water, (2) collection of field data and testing of the signature analysis, and (3) the possibility of using LANDSAT data for the identification of substances in water. An attempt to extract spectral signatures of acid waste and sediment was successful.

  12. Electrical resistivity investigation of fluvial geomorphology to evaluate potential seepage conduits to agricultural lands along the San Joaquin River, Merced County, California, 2012–13

    USGS Publications Warehouse

    Groover, Krishangi D.; Burgess, Matthew K.; Howle, James F.; Phillips, Steven P.

    2017-02-08

    Increased flows in the San Joaquin River, part of the San Joaquin River Restoration Program, are designed to help restore fish populations. However, increased seepage losses could result from these higher restoration flows, which could exacerbate existing drainage problems in neighboring agricultural lands and potentially damage crops. Channel deposits of abandoned river meanders that are hydraulically connected to the river could act as seepage conduits, allowing rapid and widespread water-table rise during restoration flows. There is a need to identify the geometry and properties of these channel deposits to assess their role in potential increased seepage effects and to evaluate management alternatives for reducing seepage. Electrical and electromagnetic surface geophysical methods have provided a reliable proxy for lithology in studies of fluvial and hyporheic systems where a sufficient electrical contrast exists between deposits of differing grain size. In this study, direct-current (DC) resistivity was used to measure subsurface resistivity to identify channel deposits and to map their subsurface geometry. The efficacy of this method was assessed by using DC resistivity surveys collected along a reach of the San Joaquin River in Merced County, California, during the summers of 2012 and 2013, in conjunction with borings and associated measurements from a hydraulic profiling tool. Modeled DC resistivity data corresponded with data from cores, hand-auger samples, a hydraulic profiling tool, and aerial photographs, confirming that DC resistivity is effective for differentiating between silt and sand deposits in this setting. Modeled DC resistivity data provided detailed two-dimensional cross-sectional resistivity profiles to a depth of about 20 meters. The distribution of high-resistivity units in these profiles was used as a proxy for identifying areas of high hydraulic conductivity. These data were used subsequently to guide the location and depth of wells

  13. Evolved star water maser cloud size determined by star size

    NASA Astrophysics Data System (ADS)

    Richards, A. M. S.; Etoka, S.; Gray, M. D.; Lekht, E. E.; Mendoza-Torres, J. E.; Murakawa, K.; Rudnitskij, G.; Yates, J. A.

    2012-10-01

    Context. Cool, evolved stars undergo copious mass loss but the detailed mechanisms and the form in which the matter is returned to the ISM are still under debate. Aims: We investigated the structure and evolution of the wind at 5 to 50 stellar radii from asymptotic giant branch and red supergiant stars. Methods: 22-GHz water masers around seven evolved stars were imaged using MERLIN, at sub-AU resolution. Each source was observed at between 2 and 7 epochs, covering several stellar periods. We compared our results with long-term single dish monitoring provided by the Pushchino radio telescope. Results: The 22-GHz emission is located in approximately spherical, thick, unevenly filled shells. The outflow velocity increases twofold or more between the inner and outer shell limits. Water maser clumps could be matched at successive epochs separated by less than two years for AGB stars, or at least 5 years for RSG. This is much shorter than the decades taken for the wind to cross the maser shell, and comparison with spectral monitoring shows that some features fade and reappear. In five sources, most of the matched maser features brighten or dim in concert from one epoch to the next. A number of individual maser features show idiosyncratic behaviour, including one cloud in W Hya caught in the act of passing in front of a background cloud leading to 50-fold, transient amplification. The masing clouds are one or two orders of magnitude denser than the wind average and contain a substantial fraction of the mass loss in this region, with a filling factor <1%. The RSG clouds are about ten times bigger than those round the AGB stars. Conclusions: Proper motions are dominated by expansion, with no systematic rotation. The maser clouds presumably survive for decades (the shell crossing time) but the masers are not always beamed in our direction. Only radiative effects can explain changes in flux density throughout the maser shells on short timescales. The size of the clouds is

  14. H-Area Seepage Basins groundwater monitoring report. Fourth quarter 1992 and 1992 summary

    SciTech Connect

    Not Available

    1993-03-01

    During fourth quarter 1992, the groundwater at the H-Area Seepage Basins (HASB) was monitored in compliance with South Carolina Hazardous Waste Management Regulations, R61-79.265, Subpart F. Samples were collected from 130 wells that monitor the three separate hydrostratigraphic units that make up the uppermost aquifer beneath the HASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B Post-Closure Care Permit Application for the H-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control in December 1990. Historically, as well as currently, tritium, nitrate, total alpha-emitting radium, gross alpha, and mercury have been the primary constituents observed above final Primary Drinking Water Standards (PDWS) in groundwater at the HASB. Isoconcentration/isoactivity maps included in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units during first and fourth quarter 1992. Water-level maps indicate that the groundwater flow rates and directions at the HASB have remained relatively constant since the basins ceased to be active in 1988.

  15. Determinants of drinking water quality in rural Nicaragua.

    PubMed

    Sandiford, P; Gorter, A C; Smith, G D; Pauw, J P

    1989-06-01

    One hundred and fifty-three water samples from rural Nicaragua were examined for the presence of faecal coliforms during both wet and dry periods. A linear model was fitted by analysis of covariance with the logarithm of the faecal coliform count as the dependent variable. As expected, traditional water sources were grossly contaminated at all times whereas piped water sources were much cleaner. Hand-dug protected wells had significantly higher levels of faecal contamination than unprotected riverside wells and springs during the dry season. The possible reasons for this unexpected finding are discussed. A close association between rainfall and faecal contamination was demonstrated but the effect of rainfall depended on the type of water source. An association between water quality and the size of the community served by the source was also detected. The finding that stored water was usually more contaminated than fresh water samples is consistent with the results from other studies. Since it is unusual for water quality to be inversely correlated with accessibility, this study site would be suitable for investigating the relative importance of water-borne versus water-washed transmission mechanisms in childhood diarrhoea.

  16. Determinants of drinking water quality in rural Nicaragua.

    PubMed Central

    Sandiford, P.; Gorter, A. C.; Smith, G. D.; Pauw, J. P.

    1989-01-01

    One hundred and fifty-three water samples from rural Nicaragua were examined for the presence of faecal coliforms during both wet and dry periods. A linear model was fitted by analysis of covariance with the logarithm of the faecal coliform count as the dependent variable. As expected, traditional water sources were grossly contaminated at all times whereas piped water sources were much cleaner. Hand-dug protected wells had significantly higher levels of faecal contamination than unprotected riverside wells and springs during the dry season. The possible reasons for this unexpected finding are discussed. A close association between rainfall and faecal contamination was demonstrated but the effect of rainfall depended on the type of water source. An association between water quality and the size of the community served by the source was also detected. The finding that stored water was usually more contaminated than fresh water samples is consistent with the results from other studies. Since it is unusual for water quality to be inversely correlated with accessibility, this study site would be suitable for investigating the relative importance of water-borne versus water-washed transmission mechanisms in childhood diarrhoea. PMID:2737254

  17. Spatial distribution of methane seepage on the East Siberian Arctic Shelf

    NASA Astrophysics Data System (ADS)

    Stubbs, C.; Leifer, I.; Shakhova, N. E.; Semiletov, I. P.; Luyendyk, B. P.

    2010-12-01

    A 2009 multibeam sonar survey of the shallow water-column (mean depth 10 m), near-coastal region of the East Siberian Arctic Shelf (ESAS) adjacent to the Lena River Delta detected tens of thousands of widespread bubble plume seeps. The ESAS contains an estimated 1400 GT (109 tons = 1 GT) of carbon sequestered within and beneath a sub-sea permafrost unit that has become inundated due to sea-level transgression over the last ~15,000 years. This carbon pool includes methane (CH4) as free and dissolved gas, as well as potentially extensive methane hydrate deposits, yet its contribution to global carbon stocks has traditionally been ignored due to the assumed integrity of the sub-sea permafrost as an impermeable barrier to hydrocarbon migration. Recent results indicate that in some regions of the ESAS, methane is migrating through destabilized permafrost into the shallow water-column from which it efficiently vents to the atmosphere. This process represents an unknown but potentially significant contribution to the global greenhouse gas budget and is likely to accelerate under global warming scenarios. We hypothesize that the mapped seeps are fed by methane deposits within and beneath capping permafrost units that release gas into the thin overlying sediments through columns of thaw sediments and other permeable structures within the permafrost. Such sub-sea permafrost features have been previously identified in association with isolated bubble plumes in the ESAS as close as 25 km from the study area (Rekant et al., 2009). These proposed migration pathways suggest thermal destabilization within the subsea permafrost cap; however, the rates at which these processes are occurring remain unknown. The spatial distributions of the most numerous and intense areas of seepage correlate with the areas of greatest fluvial discharge from the Lena and Olenek Rivers and their tributaries. This thermal influence is also evident in seasonal time series of adjacent sea ice retreat over

  18. Freshwater seepages and ephemeral macroalgae proliferation in an intertidal bay: I Effect on benthic community structure and food web

    NASA Astrophysics Data System (ADS)

    Ouisse, Vincent; Riera, Pascal; Migné, Aline; Leroux, Cédric; Davoult, Dominique

    2011-01-01

    Freshwater seepages and ephemeral Enteromorpha spp. proliferation create heterogeneity at small spatial scale in intertidal sediment. Macrobenthic community diversity was compared between these two disturbances and their respective control points throughout the year 2007 at the Roscoff Aber Bay (Western English Channel, France). In March and September 2007, trophic community pathways of characteristic species were additionally studied using stable isotope ratios of carbon and nitrogen. The low salinity recorded at the freshwater seepage induced the exclusion of the main bioturbator and the presence of omnivores which modified the community composition by biotic pressure. Moreover, food web analyses clearly highlighted a separation at small spatial scale between the two trophic pathways of the impacted area and its control. On the contrary, little differences were observed owning to the ephemeral Enteromorpha spp. proliferation. This suggested a progressive and diffusive disturbance which was applied from the algal mat to the nearby area. However, seasonal changes were observed. First, the algal expansion phase increased the macrofauna diversity and foraminifers' abundance (meiofauna) and then acted as a physical barrier decreasing sediment and water column exchanges and decreasing the fauna diversity. This study highlights the need to take into account small spatial heterogeneity to avoid misinterpretations in intertidal ecology studies.

  19. First evidence of widespread active methane seepage in the Southern Ocean, off the sub-Antarctic island of South Georgia

    NASA Astrophysics Data System (ADS)

    Römer, M.; Torres, M.; Kasten, S.; Kuhn, G.; Graham, A. G. C.; Mau, S.; Little, C. T. S.; Linse, K.; Pape, T.; Geprägs, P.; Fischer, D.; Wintersteller, P.; Marcon, Y.; Rethemeyer, J.; Bohrmann, G.

    2014-10-01

    An extensive submarine cold-seep area was discovered on the northern shelf of South Georgia during R/V Polarstern cruise ANT-XXIX/4 in spring 2013. Hydroacoustic surveys documented the presence of 133 gas bubble emissions, which were restricted to glacially-formed fjords and troughs. Video-based sea floor observations confirmed the sea floor origin of the gas emissions and spatially related microbial mats. Effective methane transport from these emissions into the hydrosphere was proven by relative enrichments of dissolved methane in near-bottom waters. Stable carbon isotopic signatures pointed to a predominant microbial methane formation, presumably based on high organic matter sedimentation in this region. Although known from many continental margins in the world's oceans, this is the first report of an active area of methane seepage in the Southern Ocean. Our finding of substantial methane emission related to a trough and fjord system, a topographical setting that exists commonly in glacially-affected areas, opens up the possibility that methane seepage is a more widespread phenomenon in polar and sub-polar regions than previously thought.

  20. Seepage-Based Factor of Safety Analysis Using 3D Groundwater Simulation Results

    DTIC Science & Technology

    2014-08-01

    FoSpiping is for pipeable topsoil (noncohesive soils such as sand) and FoSuplift for nonpipeable topsoil (cohesive soils such as clay and silt ). The FoS...Florida, to study the feasibility of a proposed Seepage Management Test Facility (SMTF) and a shallow cutoff wall alternative to mitigate seepage, as...Fill, covered by New Embankment Fill, and the lower chimney cutting through the Peat/ Silt and Interbedded Zone regions into Zone 1. The New Embankment

  1. Assessing the Impact of Animal Waste Lagoon Seepage on the Geochemistry of an Underlying Shallow Aquifer

    SciTech Connect

    McNab, W W; Singleton, M J; Moran, J E; Esser, B K

    2006-03-07

    Dairy facilities and similar confined animal operation settings pose a significant nitrate contamination threat via oxidation of animal wastes and subsequent transport to shallow groundwater. While nitrate contamination resulting from application of animal manure as fertilizer to fields is well recognized, the impact of manure lagoon leakage on groundwater quality is less well characterized. In this study, a dairy facility located in the southern San Joaquin Valley of California has been instrumented with monitoring wells as part of a two-year multidisciplinary study to evaluate nitrate loading and denitrification associated with facility operations. Among multiple types of data collected from the site, groundwater and surface water samples have been analyzed for major cations, anions, pH, oxidation-reduction potential, dissolved organic carbon, and selected dissolved gases (CO{sub 2}, CH{sub 4}, N{sub 2}, Ar, Ne). Modeling of putative geochemical processes occurring within the dairy site manure lagoons shows substantial off-gassing of CO{sub 2} and CH{sub 4} in response to mineralization of organic matter. The gas ebullition appears to strip dissolved gases, including Ar and Ne, from the lagoon water leaving concentrations that are undersaturated with respect to the atmosphere. The resulting fractionated dissolved gas signature serves as an effective tracer for the lagoon water in the underlying shallow groundwater and can be used to constrain inverse geochemical models that assess mixing fractions of lagoon water and local groundwater water. Together with ion exchange and mineral equilibria reactions, identification of lagoon seepage helps explain key attributes of the local groundwater chemistry, including input and cycling of nitrogen, across the site.

  2. Seepage investigation on selected reaches of Fish Creek, Teton County, Wyoming, 2004

    USGS Publications Warehouse

    Wheeler, Jerrod D.; Eddy-Miller, Cheryl A.

    2005-01-01

    A seepage investigation was conducted on Fish Creek, a tributary to the Snake River in Teton County in western Wyoming, near Wilson. Mainstem, return flow, tributary, spring, and diversion sites were selected and measured on six reaches along Fish Creek. Flow was measured under two flow regimes, high flow in August 2004 and base flow in November 2004. During August 17-19, 2004, 20 sites had quantifiable discharge with median values ranging from 0.93 to 384 ft3/s for the 14 mainstem sites on Fish Creek, and from 0.35 to 12.2 ft3/s for the 5 return, spring, and tributary sites (inflows). The discharge was 2.23 ft3/s for the single diversion site (outflow). Estimated gains or losses from ground water were calculated for all reaches using the median discharge values and the estimated measurement errors. Reach 1 had a calculated gain in discharge from ground water (23.8 ?3.3 ft3/s). Reaches 2-6 had no calculated gains in flow, greater than the estimated error, that could be attributed to ground water. A second set of measurements were made under base-flow conditions during November 3-4, 2004. Twelve of the 20 sites visited in August 2004 were flowing and were measured. All of the Reach 1 sites near Teton Village were dry. Median discharge values ranged from 10.3 to 70.0 ft3/s on the nine Fish Creek mainstem sites, and from 2.32 to 3.71 ft3/s on the three return, spring, and tributary sites (inflows). Reaches 2, 3 and 6 had a gain from ground water. Reaches 4 and 5 had no calculated gains in flow, greater than the estimated error, that could be attributed to ground water.

  3. [Determination of the redox potential of water saturated with hydrogen].

    PubMed

    Piskarev, I M; Ushkanov, V A; Aristova, N A; Likhachev, P P; Myslivets, T C

    2010-01-01

    It has been shown that the redox potential of water saturated with hydrogen is -500--700 mV. The time of the establishment of the potential is 24 h. The potential somewhat increases with increasing volume of hydrogen introduced to a reservoir with water and practically does not depend on the presence of additions in water, provided these additions are not reduced by hydrogen. The pH value of water does not change after the addition of water. In a glass vessel with a metallic cover resting on the side, no decrease in potential during the 2.5-month storage was observed. In plastic bottles, the content of hydrogen decreased; on storage for more than two weeks, it disappeared almost completely, and as a result, the potential increased after storage for three to four weeks to a level near zero. In an open vessel, the potential remained negative for two days.

  4. Rapid, quantitative determination of bacteria in water. [adenosine triphosphate

    NASA Technical Reports Server (NTRS)

    Chappelle, E. W.; Picciolo, G. L.; Thomas, R. R.; Jeffers, E. L.; Deming, J. W. (Inventor)

    1978-01-01

    A bioluminescent assay for ATP in water borne bacteria is made by adding nitric acid to a water sample with concentrated bacteria to rupture the bacterial cells. The sample is diluted with sterile, deionized water, then mixed with a luciferase-luciferin mixture and the resulting light output of the bioluminescent reaction is measured and correlated with bacteria present. A standard and a blank also are presented so that the light output can be correlated to bacteria in the sample and system noise can be substracted from the readings. A chemiluminescent assay for iron porphyrins in water borne bacteria is made by adding luminol reagent to a water sample with concentrated bacteria and measuring the resulting light output of the chemiluminescent reaction.

  5. Quantifying time-varying ground-water discharge and recharge in wetlands of the northern Florida Everglades

    USGS Publications Warehouse

    Choi, J.; Harvey, J.W.

    2000-01-01

    Developing a more thorough understanding of water and chemical budgets in wetlands depends in part on our ability to quantify time-varying interactions between ground water and surface water. We used a combined water and solute mass balance approach to estimate time-varying ground-water discharge and recharge in the Everglades Nutrient Removal project (ENR), a relatively large constructed wetland (1544 hectare) built for removing nutrients from agricultural drainage in the norther Everglades in South Florida, USA. Over a 4-year period (1994 through 1998), ground-water recharge averaged 13.4 hectare-meter per day (ha-m/day) or 0.9 cm/day, which is approximately 31% of surface water pumped into the ENR for treatment. In contrast, ground-water discharge was much smaller (1.4 ha-m/day, or 0.09 cm/day, or 2.8% of water input to ENR for treatment). Using a water-balance approach alone only allowed net ground-water exchange (discharge - recharge) to be estimated (-12 ?? 2.4 ha-ma/day). Disharge and recharge were individually determined by combining a chloride mass balance with the water balance. For a variety of reasons, the ground-water discharge estimated by the combined mass balance approach was not reliable (1.4 ?? 37 ha-m/day). As a result, ground-water interactions could only be reliably estimated by comparing the mass-balance results with other independent approaches, including direct seepage-meter measurements and previous estimates using ground-water modeling. All three independent approaches provided similar estimates of average ground-water recharge, ranging from 13 to 14 ha-m/day. There was also relatively good agreement between ground-water discharge estimates for the mass balance and seepage meter methods, 1.4 and 0.9 ha-m/day, respectively. However, ground-water-flow modeling provided an average discharge estimate that was approximately a factor of four higher (5.4 ha-m/day) than the other two methods. Our study developed an initial understanding of how the

  6. Delineating a road-salt plume in lakebed sediments using electrical resistivity, piezometers, and seepage meters at Mirror Lake, New Hampshire, U.S.A

    USGS Publications Warehouse

    Toran, Laura; Johnson, Melanie; Nyquist, Jonathan E.; Rosenberry, Donald O.

    2010-01-01

    Electrical-resistivity surveys, seepage meter measurements, and drive-point piezometers have been used to characterize chloride-enriched groundwater in lakebed sediments of Mirror Lake, New Hampshire, U.S.A. A combination of bottom-cable and floating-cable electrical-resistivity surveys identified a conductive zone (<100ohm-m)">(<100ohm-m)(<100ohm-m) overlying resistive bedrock (<1000ohm-m)">(<1000ohm-m)(<1000ohm-m)beneath the lake. Shallow pore-water samples from piezometers in lakebed sediments have chloride concentrations of 200–1800μeq/liter">200–1800μeq/liter200–1800μeq/liter, and lake water has a chloride concentration of 104μeq/liter">104μeq/liter104μeq/liter. The extent of the plume was estimated and mapped using resistivity and water-sample data. The plume (20×35m">20×35m20×35m wide and at least 3m">3m3m thick) extends nearly the full length and width of a small inlet, overlying the top of a basin formed by the bedrock. It would not have been possible to mapthe plume's shape without the resistivity surveys because wells provided only limited coverage. Seepage meters were installed approximately 40m">40m40m from the mouth of a small stream discharging at the head of the inlet in an area where the resistivity data indicated lake sediments are thin. These meters recorded in-seepage of chloride-enriched groundwater at rates similar to those observed closer to shore, which was unexpected because seepage usually declines away from shore. Although the concentration of road salt in the northeast inlet stream is declining, the plume map and seepage data indicate the groundwater contribution of road salt to the lake is not declining. The findings demonstrate the benefit of combining geophysical and hydrologic data to characterize discharge of a plume beneath Mirror Lake. The extent of the plume in groundwater beneath the lake and stream indicate there will likely be a long-term source of chloride to the lake from groundwater.

  7. Methane seepage along the Hikurangi Margin offshore New Zealand: 6 years of multidisciplinary studies

    NASA Astrophysics Data System (ADS)

    Greinert, J.; Bialas, J.; Klaucke, I.; Crutchley, G.; Dale, A.; Linke, P.; Sommer, S.; Bowden, D.; Rowden, A.; de Haas, H.; de Stigter, H.; Faure, K.

    2012-12-01

    Detailed studies in 2006, 2007 and 2011 along the east coast of New Zealand's North Island highlighted the close link of sub-bottom fluid pathways and seafloor expressions of methane seepage such as clam fields, carbonate build-ups, tubeworms, bacterial mats and methane release (Marine Geology 272). Prior to our studies, only accidental observations of hydroacoustic anomalies, recoveries of calyptogena shells and methane-derived carbonate chimneys indicated active seepage. Wide areas of the sub-seafloor show BSR structures, gas migration pathways, gas chimneys and blanking zones, which are closely linked to actual seep sites. Sidescan surveys showed four prominent seep areas at Omakere Ridge in 1120m water depth, three of them perfectly matching the shapes and locations of faults seen in high resolution 3D-seismic surveys. The fourth seep, Bear's Paw, on its western side represents an old seep which developed into a cold water coral habitat. At the actively seeping eastern part, gas hydrates could be retrieved and bubble release was observed hydroacoustically and confirmed by high dissolved methane values (380nM). No strong microbial oxidation effects could be found in δ13C values plotting along a mixing curve between pure seep (-70 ‰PDB) and atmospheric methane (-47 ‰PDB). Lander deployments show a tide-influenced gas discharge with sometimes eruptive bubble release with possible plume development transporting methane-charged water higher up into the water column. Rock Garden, with just above 600m water depth at its top outside the gas hydrate stability zone, hosts two main seep areas. ROV observations at Faure Site document eruptive releases of free gas from decimeter-wide craters at the seafloor. Flux estimates show peak releases of 420ml/min with bubbles up to 9mm in diameter. Concentrations of dissolved methane reach up to 3500nM close to the bottom, but higher concentrations are limited to below 400m of water depth; here, methane is transported towards

  8. Natural hydrocarbon seepage on the continental slope to the east of Mississippi Canyon in the northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Rahman Talukder, Asrarur; Ross, Andrew; Crooke, Emma; Stalvies, Charlotte; Trefry, Christine; Qi, Xiubin; Fuentes, David; Armand, Stephane; Revill, Andrew

    2013-06-01

    5 June to 15 September 2010, a multidisciplinary marine survey was undertaken onboard the M/V Ryan Chouest in the region of the BP Deepwater Horizon incident site in the Gulf of Mexico. The primary objective of the survey was the continuous monitoring of hydrocarbon abundance from sea surface down to a maximum depth of 120 m. Compound abundances were inferred using a hydrocarbon sensor array with associated vertical cast system. In order to better understand the potential inputs from natural seepage in the vicinity of the spill, a Simrad EK60 high-resolution split beam echo sounder, operated at 38 kHz, was included in the survey between 7 July and 15 September 2010. During this period, three fields of natural seeps characterized by hydroacoustic flares were studied in detail. These seep fields are at water depths of approximately 430 m, 880 m, and 1370 m. They are associated with extensive cold seep systems. In particular, the area around Seep Field 1 (the vicinity of Deepwater Horizon) seems to present a vast area of active natural seepages in the Gulf of Mexico. The repeat surveys at two of the fields suggested that the cold seep systems here were active, with expulsions of hydrocarbons into the water column, at least during the periods of our acoustic surveys. Multiple lines of evidence gathered during the survey indicated that the observed hydroacoustic flares at the three fields identified consisted of oily bubble streams of gases of thermogenic origin. However, direct observation and sampling are required to reveal the precise nature of the flares. In the deep water Gulf of Mexico, the formation of a hydrate rim around bubbles seems to be a very important mechanism for the long transport of methane and oil in the water column.

  9. Exploring the long-term balance between net precipitation and net groundwater exchange in Florida seepage lakes

    USGS Publications Warehouse

    Lee, Terrie M.; Sacks, Laura A.; Swancar, Amy

    2014-01-01

    The long-term balance between net precipitation and net groundwater exchange that maintains thousands of seepage lakes in Florida’s karst terrain is explored at a representative lake basin and then regionally for the State’s peninsular lake district. The 15-year water budget of Lake Starr includes El Niño Southern Oscillation (ENSO)-related extremes in rainfall, and provides the longest record of Bowen ratio energy-budget (BREB) lake evaporation and lake-groundwater exchanges in the southeastern United States. Negative net precipitation averaging -25 cm/yr at Lake Starr overturns the previously-held conclusion that lakes in this region receive surplus net precipitation. Net groundwater exchange with the lake was positive on average but too small to balance the net precipitation deficit. Groundwater pumping effects and surface-water withdrawals from the lake widened the imbalance. Satellite-based regional estimates of potential evapotranspiration at five large lakes in peninsular Florida compared well with basin-scale evaporation measurements from seven open-water sites that used BREB methods. The regional average lake evaporation estimated for Lake Starr during 1996-2011 was within 5 percent of its measured average, and regional net precipitation agreed within 10 percent. Regional net precipitation to lakes was negative throughout central peninsular Florida and the net precipitation deficit increased by about 20 cm from north to south. Results indicate that seepage lakes farther south on the peninsula receive greater net groundwater inflow than northern lakes and imply that northern lakes are in comparatively leakier hydrogeologic settings. Findings reveal the peninsular lake district to be more vulnerable than was previously realized to drier climate, surface-water withdrawals from lakes, and groundwater pumping effects.

  10. Exploring the long-term balance between net precipitation and net groundwater exchange in Florida seepage lakes

    NASA Astrophysics Data System (ADS)

    Lee, Terrie M.; Sacks, Laura A.; Swancar, Amy

    2014-11-01

    The long-term balance between net precipitation and net groundwater exchange that maintains thousands of seepage lakes in Florida's karst terrain is explored at a representative lake basin and then regionally for the State's peninsular lake district. The 15-year water budget of Lake Starr includes El Niño Southern Oscillation (ENSO)-related extremes in rainfall, and provides the longest record of Bowen ratio energy-budget (BREB) lake evaporation and lake-groundwater exchanges in the southeastern United States. Negative net precipitation averaging -25 cm/yr at Lake Starr overturns the previously-held conclusion that lakes in this region receive surplus net precipitation. Net groundwater exchange with the lake was positive on average but too small to balance the net precipitation deficit. Groundwater pumping effects and surface-water withdrawals from the lake widened the imbalance. Satellite-based regional estimates of potential evapotranspiration at five large lakes in peninsular Florida compared well with basin-scale evaporation measurements from seven open-water sites that used BREB methods. The regional average lake evaporation estimated for Lake Starr during 1996-2011 was within 5% of its measured average, and regional net precipitation agreed within 10%. Regional net precipitation to lakes was negative throughout central peninsular Florida and the net precipitation deficit increased by about 20 cm from north to south. Results indicate that seepage lakes farther south on the peninsula receive greater net groundwater inflow than northern lakes and imply that northern lakes are in comparatively leakier hydrogeologic settings. Findings reveal the peninsular lake district to be more vulnerable than was previously realized to drier climate, surface-water withdrawals from lakes, and groundwater pumping effects.

  11. Simultaneous ultraviolet spectrophotometric determination of nitrate and nitrite in water

    SciTech Connect

    Dong Huiru; Zhang Qing ); Jiang Meiyu )

    1991-02-01

    A rapid and accurate method for the direct simultaneous determination of nitrate and nitrite is proposed. The method is applied to the determination of nitrate and nitrite in rainwater and wastewater without preliminary separation. The determinations are performed by a CPA matrix method with ultraviolet spectrophotometric detection. The results obtained are in agreement with those obtained by conventional methods for the determination of nitrate and nitrite.

  12. Hydrocarbon Seepage during the Boreal Base Cretaceous Hot Shale Event

    NASA Astrophysics Data System (ADS)

    Hammer, Ø.; Hryniewicz, K.; Nakrem, H. A.; Little, C.

    2014-12-01

    We have identified a number of carbonate bodies interpreted as seep-related from near the Jurassic-Cretaceous boundary in Svalbard, arctic Norway. The paleoseeps discovered so far occur over 50 km along strike, representing a seepage field of considerable extent. Ammonites indicate a base Cretaceous (Late Volgian to Late Ryazanian) age. The carbonate bodies are highly fossiliferous, with a very diverse fauna consisting mainly of normal-marine species but also seep-restricted taxa. Carbonate d13C isotopes reach -46‰, which, considering mixture with seawater-derived carbon, is interpreted as indicating a biogenic methane source. It is of interest to note the correlation of this paleoseepage with an episode of extremely high burial of organic matter near the Jurassic-Cretaceous boundary, noted both in Svalbard (top Slottsmøya Member of the Agardhfjellet Formation), in the Barents Sea (Hekkingen Formation) and in the North Sea (Mandal Formation), possibly providing a shallow source for biogenic gas. Together with near contemporaneous events in the Boreal Realm such as ongoing rifting, the base Cretaceous unconformity, the Mjølnir meteorite impact and a possible minor extinction event, these finds contribute to the impression of the Jurassic-Cretaceous boundary as a highly dynamic and interesting time in the North Atlantic area.

  13. Mapping methane from marine and terrestrial hydrocarbon seepage using AVIRIS

    NASA Astrophysics Data System (ADS)

    Thorpe, A. K.; Bradley, E. S.; Funk, C.; Roberts, D. A.; Leifer, I.; Dennison, P. E.; Margolis, J.

    2010-12-01

    Concentrations of atmospheric methane (CH4), a greenhouse gas at least 20 times more potent per molecule than carbon dioxide (CO2), have more than doubled in the last two centuries. Due to a lack of direct measurements of sources and sinks, the global methane budget is poorly constrained and emissions of this important greenhouse gas are often underestimated in climate models. The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) recently mapped methane emissions from the Coal Oil Point (COP) marine seep fields, a concentrated geologic methane source (0.015 Tg yr-1 from ~3 km2) located offshore from Santa Barbara, CA using a residual-based approach (Roberts et al. 2010) and short-wave infrared band ratios (Bradley et al. submitted). In this study, an additional cluster-tuned matched filter technique adapted from Funk et al. 2001 detected methane anomalies for COP that closely matched previous results and were in agreement with sonar-based seep surveys and flux buoy data. This technique was also applied to AVIRIS data acquired over the La Brea Tar Pits in Los Angeles, CA, a region known for natural oil and methane seepage. Significant anomalies were identified for known methane sources close to the tar pits where pipes have been established to prevent dangerous methane buildup. Therefore, imaging spectrometry using sensors like AVIRIS and planned satellite sensors like HyspIRI has the potential to greatly improve high spatial resolution mapping of methane emissions, thereby better constraining regional methane sources.

  14. Estimating Water Fluxes Across the Sediment-Water Interface in the Lower Merced River, California

    USGS Publications Warehouse

    Zamora, Celia

    2008-01-01

    The lower Merced River Basin was chosen by the U.S. Geological Survey?s (USGS) National Water Quality Assessment Program (NAWQA) to be included in a national study on how hydrological processes and agricultural practices interact to affect the transport and fate of agricultural chemicals. As part of this effort, surface-water?ground-water (sw?gw) interactions were studied in an instrumented 100-m reach on the lower Merced River. This study focused on estimating vertical rates of exchange across the sediment?water interface by direct measurement using seepage meters and by using temperature as a tracer coupled with numerical modeling. Temperature loggers and pressure transducers were placed in monitoring wells within the streambed and in the river to continuously monitor temperature and hydraulic head every 15 minutes from March 2004 to October 2005. One-dimensional modeling of heat and water flow was used to interpret the temperature and head observations and deduce the sw?gw fluxes using the USGS numerical model, VS2DH, which simulates variably saturated water flow and solves the energy transport equation. Results of the modeling effort indicate that the Merced River at the study reach is generally a slightly gaining stream with small head differences (cm) between the surface water and ground water, with flow reversals occurring during high streamflow events. The average vertical flux across the sediment?water interface was 0.4?2.2 cm/day, and the range of hydraulic conductivities was 1?10 m/day. Seepage meters generally failed to provide accurate data in this high-energy system because of slow seepage rates and a moving streambed resulting in scour or burial of the seepage meters. Estimates of streambed hydraulic conductivity were also made using grain-size analysis and slug tests. Estimated hydraulic conductivity for the upstream transect determined using slug tests ranged from 40 to 250 m/day, whereas the downstream transect ranged from 10 to 100 m/day. The

  15. Greenhouse gases generated from the anaerobic biodegradation of natural offshore asphalt seepages in southern California

    USGS Publications Warehouse

    Lorenson, T.D.; Wong, Florence L.; Dartnell, Peter; Sliter, Ray W.

    2014-01-01

    Significant offshore asphaltic deposits with active seepage occur in the Santa Barbara Channel offshore southern California. The composition and isotopic signatures of gases sampled from the oil and gas seeps reveal that the coexisting oil in the shallow subsurface is anaerobically biodegraded, generating CO2 with secondary CH4 production. Biomineralization can result in the consumption of as much as 60% by weight of the original oil, with 13C enrichment of CO2. Analyses of gas emitted from asphaltic accumulations or seeps on the seafloor indicate up to 11% CO2 with 13C enrichment reaching +24.8‰. Methane concentrations range from less than 30% up to 98% with isotopic compositions of –34.9 to –66.1‰. Higher molecular weight hydrocarbon gases are present in strongly varying concentrations reflecting both oil-associated gas and biodegradation; propane is preferentially biodegraded, resulting in an enriched 13C isotopic composition as enriched as –19.5‰. Assuming the 132 million barrels of asphaltic residues on the seafloor represent ~40% of the original oil volume and mass, the estimated gas generated is 5.0×1010 kg (~76×109 m3) CH4 and/or 1.4×1011 kg CO2 over the lifetime of seepage needed to produce the volume of these deposits. Geologic relationships and oil weathering inferences suggest the deposits are of early Holocene age or even younger. Assuming an age of ~1,000 years, annual fluxes are on the order of 5.0×107 kg (~76×106 m3) and/or 1.4×108 kg for CH4 and CO2, respectively. The daily volumetric emission rate (2.1×105 m3) is comparable to current CH4 emission from Coal Oil Point seeps (1.5×105 m3/day), and may be a significant source of both CH4 and CO2 to the atmosphere provided that the gas can be transported through the water column.

  16. Greenhouse gases generated from the anaerobic biodegradation of natural offshore asphalt seepages in southern California

    NASA Astrophysics Data System (ADS)

    Lorenson, Thomas D.; Wong, Florence L.; Dartnell, Peter; Sliter, Ray W.

    2014-06-01

    Significant offshore asphaltic deposits with active seepage occur in the Santa Barbara Channel offshore southern California. The composition and isotopic signatures of gases sampled from the oil and gas seeps reveal that the coexisting oil in the shallow subsurface is anaerobically biodegraded, generating CO2 with secondary CH4 production. Biomineralization can result in the consumption of as much as 60% by weight of the original oil, with 13C enrichment of CO2. Analyses of gas emitted from asphaltic accumulations or seeps on the seafloor indicate up to 11% CO2 with 13C enrichment reaching +24.8‰. Methane concentrations range from less than 30% up to 98% with isotopic compositions of -34.9 to -66.1‰. Higher molecular weight hydrocarbon gases are present in strongly varying concentrations reflecting both oil-associated gas and biodegradation; propane is preferentially biodegraded, resulting in an enriched 13C isotopic composition as enriched as -19.5‰. Assuming the 132 million barrels of asphaltic residues on the seafloor represent ~40% of the original oil volume and mass, the estimated gas generated is 5.0×1010 kg (~76×109 m3) CH4 and/or 1.4×1011 kg CO2 over the lifetime of seepage needed to produce the volume of these deposits. Geologic relationships and oil weathering inferences suggest the deposits are of early Holocene age or even younger. Assuming an age of ~1,000 years, annual fluxes are on the order of 5.0×107 kg (~76×106 m3) and/or 1.4×108 kg for CH4 and CO2, respectively. The daily volumetric emission rate (2.1×105 m3) is comparable to current CH4 emission from Coal Oil Point seeps (1.5×105 m3/day), and may be a significant source of both CH4 and CO2 to the atmosphere provided that the gas can be transported through the water column.

  17. Removal Site Evaluation Report to the C-Reactor Seepage Basins (904-066, -067 and -068G)

    SciTech Connect

    Palmer, E.R.

    1997-07-01

    Removal Site Evaluation Reports are prepared in accordance with Section 300.410 of the National Contingency Plan (NCP) and Section X of the Federal Facility Agreement (FFA). The C-Reactor Seepage Basins (904-066G,-067G,-068G) are listed in Appendix C, Resource Conservation and Recovery Act (RCRA)/Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Units List, of the FFA. The purpose of this investigation is to report information concerning conditions at this unit sufficient to assess the threat (if any) posed to human health and the environment and to determine the need for additional CERCLA action. The scope of the investigation included a review of past survey and investigation data, the files, and a visit to the unit.Through this investigation unacceptable conditions of radioactive contaminant uptake in on-site vegetation were identified. This may have resulted in probable contaminant migration and become introduced into the local ecological food chain. As a result, the SRS will initiate a time critical removal action in accordance with Section 300.415 of the NCP and FFA Section XIV to remove, treat (if required), and dispose of contaminated vegetation from the C-Reactor Seepage Basins. Erosion in the affected areas will be managed by an approved erosion control plan. further remediation of this unit will be conducted in accordance with the FFA.

  18. F-Area Seepage Basins groundwater monitoring report. Fourth quarter 1992 and 1992 summary

    SciTech Connect

    Not Available

    1993-03-01

    During fourth quarter 1992, the groundwater at the F-Area Seepage Basins (FASB) was monitored in compliance with South Carolina Hazardous Waste Management Regulations, R61-79.265, Subpart F. Eighty-five wells provided samples from the three hydrostratigraphic units that make up the uppermost aquifer beneath the FASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B Post-Closure Care Permit Application for the F-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control in December 1990. Historically, as well as currently, tritium, nitrate, gross alpha, total alpha-emitting radium, cadmium, and lead are the primary constituents observed above final Primary Drinking Water Standards (PDWS) in groundwater at the FASB. Nonvolatile beta has consistently exceeded its drinking water screening level. Other radionuclides and hazardous constituents also have exceeded the final PDWS in the groundwater at the FASB. The elevated constituents are found primarily in Aquifer Zone IIB{sub 2} (Water Table) and Aquifer Zone IIB{sub 1}, (Barnwell/McBean) wells. However, several Aquifer Unit IIA (Congaree) wells also contain elevated levels of constituents, primarily tritium. Isoconcentration/isoactivity maps included in this report indicate both the concentration/ activity and extent of the primary contaminants in each of the three hydrostratigraphic units for first and fourth quarters 1992. Water-level maps indicate that the groundwater flow rates and directions at the FASB have remained relatively constant since the basins ceased to be active in 1988.

  19. Identifying and Determining Halocarbons in Water Using Headspace Gas Chromatography.

    DTIC Science & Technology

    1981-10-01

    brought it under scrutiny. While the health effects of chlorination are still being evaluated and alternative disinfection methods are being sought,6...20 5-2 14 . 6. Jolley, R.L., ed. (1978) Water chlorination environmental impact and health effects, vol. 1. Ann Arbor, Michigan: Ann Arbor Science. 7...chloroform and other haloforms are produced during water chlorination , methods have been needed for their routine analysis. This report describes

  20. IAEA proficiency tests for determination of radionuclides in sea water.

    PubMed

    Harms, Arend; Khanh Pham, Mai; Blinova, Oxana; Tarjan, Sandor; Nies, Hartmut; Osvath, Iolanda

    2017-02-14

    The International Atomic Energy Agency organised four proficiency tests between 2012 and 2015 to test the performance of participating laboratories in an analysis of radionuclides in sea water samples. These exercises were initiated to support IAEA Member States in sea water analyses of tritium, strontium-90 and caesium isotopes in relation to the accident at the Fukushima Daiichi nuclear power station, in March 2011, and subsequent contamination of the marine environment.

  1. Soil-atmosphere and vadose zone water fluxes at the Wagna - lysimeter: Workflow, models, and results

    NASA Astrophysics Data System (ADS)

    Fank, Johann

    2014-05-01

    A precise knowledge of the water fluxes between the soil-plant system and the atmosphere is of great importance for understanding and modeling water, solute and energy transfer in the soil-plant-atmosphere system. Weighing lysimeters are precise tools to allow the determination of the hydrological cycle components in very short time intervals. Lysimeters with controlled suction at the lower boundary allow estimation of capillary rise and deep water percolation on short time scales. Evapotranspiration, rainfall, and irrigation can be computed from weight changes. In the last decades resolution and precision of the weighing systems have been substantially improved, so that modern lysimeters, resting on weighing cells can reach resolutions of up to 0.01 mm. Nevertheless, a lot of external effects (e.g. from maintenance, surface treatment) and small mechanical disturbances (e.g. caused by wind) became visible in the data. Seepage mass data are affected by water sampling and the emptying process of the seepage water container. Increasing parts of corrected seepage mass data show deep water percolation, decreasing parts in dry weather periods can be interpreted as capillary rise. In the evaluation process of corrected lysimeter mass data every increase in system weight (lysimeter mass + cumulative seepage mass) might be interpreted as rainfall or irrigation, whereas every decrease in system weight is interpreted as evapotranspiration. To apply this concept correctly, the noise in both data sets has to be separated from signals using a filtering routine (e.g. Peters et al., 2013) which is appropriate for any event, including events with low disturbances as well as strong wind and heavy precipitation in small time intervals. Based on the data set from the "Wagna" lysimeter in Austria with a high resolution of the scale (~ 0,015 mm) and very low noise due to low wind velocities for the year 2010 a lysimeter data preparation workflow will be executed: (a) correction of the

  2. H-Area Seepage Basins groundwater monitoring report. Volume 1, First and second quarters 1993

    SciTech Connect

    Not Available

    1993-09-01

    During the first half of 1993, the groundwater at the H-Area Seepage Basins (HASB) was monitored in compliance with the September 30, 1992, modification of South Carolina Hazardous Waste Permit. Samples were collected from 130 wells that monitor the three separate hydrostratigraphic units that make up the uppermost aquifer beneath the HASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B Post-Closure Care Permit Application for the H-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control (SCDHEC) in December 1990. HASB`s Groundwater Protection Standard is the standard for comparison. Historically, as well as currently, gross alpha, nitrate, nonvolatile beta, and tritium have been among the primary constituents to exceed standards. Other radionuclides and hazardous constituents also exceeded the GWPS in the groundwater at the HASB, notably aluminum, iodine-129, mercury, nickel-63, strontium-89, strontium-90, technetium-99, and zinc during the first half of 1993. Elevated constituents are found primarily in Aquifer Zone IIB{sub 2} (Water Table) and in the upper portion of Aquifer Zone IIB{sub 1}. However, constituents exceeding standards also occur in several wells screened in the lower portion of Aquifer Zone IIB{sub 1} and Aquifer Unit IIA.

  3. Gas chromatographic determination of water in organic compounds and of organic compounds in water after steam distillations

    SciTech Connect

    Dix, K.D.

    1990-01-01

    A gas chromatograph (GC) with a flame ionization detector (FID) is shown to be effective in the determination of water in organic compounds. Since the FID gives little response for water, a reaction is needed to convert water into a detectable species. The ketal, 2,2-dimethoxypropane (DMP), reacts quantitatively with water to yield the products methanol and acetone when an acid catalyst is present. Acetone is easily determined with a GC equipped with a capillary column and FID. A solid acid catalyst, Nafion, has been effective and is easily separated before sample introduction into the GC.

  4. Determinants of cyanuric acid and melamine assembly in water.

    PubMed

    Ma, Mingming; Bong, Dennis

    2011-07-19

    While the recognition of cyanuric acid (CA) by melamine (M) and their derivatives has been known to occur in both water and organic solvents for some time, analysis of CA/M assembly in water has not been reported (Ranganathan, A.; Pedireddi, V. R.; Rao, C. N. R. J. Am. Chem. Soc.1999, 121, 1752-1753; Mathias, J. P.; Simanek, E. E.; Seto, C. T.; Whitesides, G. M. Macromol. Symp.1994, 77, 157-166; Zerkowski, J. A.; MacDonald, J. C.; Seto, C. T.; Wierda, D. A.; Whitesides, G. M. J. Am. Chem. Soc.1994, 116, 2382-2391; Mathias, J. P.; Seto, C. T.; Whitesides, G. M. Polym. Prepr.1993, 34, 92-93; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1993, 115, 905-916; Zerkowski, J. A.; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1992, 114, 5473-5475; Seto, C. T.; Whitesides, G. M. J. Am. Chem. Soc.1990, 112, 6409-6411; Wang, Y.; Wei, B.; Wang, Q. J. Chem. Cryst.1990, 20, 79-84; ten Cate, M. G. J.; Huskens, J.; Crego-Calama, M.; Reinhoudt, D. N. Chem.-Eur. J.2004, 10, 3632-3639). We have examined assembly of CA/M, as well as assembly of soluble trivalent CA and M derivatives (TCA/TM), in aqueous solvent, using a combination of solution phase NMR, isothermal titration and differential scanning calorimetry (ITC/DSC), cryo-transmission electron microscopy (cryo-TEM), and synthetic chemistry. While the parent heterocycles coprecipitate in water, the trivalent system displays more controlled and cooperative assembly that occurs at lower concentrations than the parent and yields a stable nanoparticle suspension. The assembly of both parent and trivalent systems is rigorously 1:1 and proceeds as an exothermic, proton-transfer coupled process in neutral pH water. Though CA and M are considered canonical hydrogen-bonding motifs in organic solvents, we find that their assembly in water is driven in large part by enthalpically favorable surface-area burial, similar to what is observed with nucleic acid recognition. There are currently few synthetic systems capable of robust molecular

  5. Determination of estrogenic potential in waste water without sample extraction.

    PubMed

    Avberšek, Miha; Žegura, Bojana; Filipič, Metka; Uranjek-Ževart, Nataša; Heath, Ester

    2013-09-15

    This study describes the modification of the ER-Calux assay for testing water samples without sample extraction (NE-(ER-Calux) assay). The results are compared to those obtained with ER-Calux assay and a theoretical estrogenic potential obtained by GC-MSD. For spiked tap and waste water samples there was no statistical difference between estrogenic potentials obtained by the three methods. Application of NE-(ER-Calux) to "real" influent and effluents from municipal waste water treatment plants and receiving surface waters found that the NE-(ER-Calux) assay gave higher values compared to ER-Calux assay and GC-MSD. This is explained by the presence of water soluble endocrine agonists that are usually removed during extraction. Intraday dynamics of the estrogenic potential of a WWTP influent and effluent revealed an increase in the estrogenic potential of the influent from 12.9 ng(EEQ)/L in the morning to a peak value of 40.0 ng(EEQ)/L in the afternoon. The estrogenic potential of the effluent was

  6. Determinants of household water conservation: The role of demographic, infrastructure, behavior, and psychosocial variables

    NASA Astrophysics Data System (ADS)

    Fielding, Kelly S.; Russell, Sally; Spinks, Anneliese; Mankad, Aditi

    2012-10-01

    Securing water supplies in urban areas is a major challenge for policy makers, both now and into the future. This study aimed to identify the key determinants of household water use, with a view to identifying those factors that could be targeted in water demand management campaigns. Objective water use data and surveys were collected from 1008 households in four local government areas of southeast Queensland, Australia. Results showed that demographic, psychosocial, behavioral, and infrastructure variables all have a role to play in determining household water use. Consistent with past research, household occupancy was the most important predictor of water use. Households in regions recently exposed to drought conditions and higher-level restrictions also used less water than those who had less experience with drought. The effect of water efficient technology was mixed: some water efficient appliances were associated with less water use, while others were associated with more water use. Results also demonstrated the importance of considering water use as a collective behavior that is influenced by household dynamics. Households who reported a stronger culture of water conservation used less water. These findings, along with evidence that good water-saving habits are linked to water conservation, highlight the value of policies that support long-term cultural shifts in the way people think about and use water.

  7. Determining the optimum solar water pumping system for domestic use, livestock water, or irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For several years we have field tested many different types of solar powered water pumping systems. In this paper, several steps are given to select a solar-PV water pumping system. The steps for selection of stand-alone water pumping system were: deciding whether a wind or solar water pumping sys...

  8. Carbon cycling fed by methane seepage at the shallow Cumberland Bay, South Georgia, sub-Antarctic

    NASA Astrophysics Data System (ADS)

    Geprägs, Patrizia; Torres, Marta E.; Mau, Susan; Kasten, Sabine; Römer, Miriam; Bohrmann, Gerhard

    2016-04-01

    Recent studies have suggested that the marine contribution of methane from shallow regions and melting marine-terminating glaciers may have been underestimated. Here we report on methane sources and potential sinks associated with methane seeps in Cumberland Bay, South Georgia's largest fjord system. The average organic carbon content in the upper 8 m of the sediment is around 0.65 wt %; this observation combined with Parasound data suggest that the methane gas accumulations probably originate from peat-bearing sediments currently located several tens of meters below the seafloor. Only one of our cores indicates upward advection; instead most of the methane is transported via diffusion. Sulfate and methane flux estimates indicate that a large fraction of methane is consumed by anaerobic oxidation of methane (AOM). Carbon cycling at the sulfate-methane transition (SMT) results in a marked fractionation of the δ13C-CH4 from an estimated source value of -65‰ to a value as low as -96‰ just below the SMT. Methane concentrations in sediments are high, especially close to the seepage sites (˜40 mM); however, concentrations in the water column are relatively low (max. 58 nM) and can be observed only close to the seafloor. Methane is trapped in the lowermost water mass; however, measured microbial oxidation rates reveal very low activity with an average turnover of 3.1 years. We therefore infer that methane must be transported out of the bay in the bottom water layer. A mean sea-air flux of only 0.005 nM/m2 s confirms that almost no methane reaches the atmosphere.

  9. The Determination of Anionic Surfactants in Natural and Waste Waters.

    ERIC Educational Resources Information Center

    Crisp, P. T.; And Others

    1983-01-01

    Background information, procedures, and results of an experiment suitable for measuring subpart per million concentrations of anionic surfactants in natural waters and waste effluents are provided. The experiment required only a spectrophotometer or filter photometer and has been successfully performed by students in an undergraduate environmental…

  10. Determining the Utility Value of Water-Supply Interconnections.

    ERIC Educational Resources Information Center

    Hardman, James L.; Cheremisinoff, Paul N.

    1979-01-01

    This article is the third in a series which discusses a mathematical methodology for evaluating interconnections of water supply systems. The model can be used to analyze the carrying capacity of proposed links or predict the impact of abandoning interconnections. (AS)

  11. DETERMINING HOW VAPOR PHASE MTBE REACHES GROUND WATER

    EPA Science Inventory

    EPA Region 2 and ORD have funded a RARE project for FY 2005/2006 to evaluate the prospects that MTBE (and other fuel components) in vapors that escape from an underground storage tank (UST) can find its way to ground water produced by monitoring wells at a gasoline filling statio...

  12. A new method for determining water uptake in elderberry plantation

    NASA Astrophysics Data System (ADS)

    Tőkei, László; Dunkel, Zoltán; Jung, András

    A considerable quantity of elderberry ( Sambucus nigra L.) fruit gets yearly on the market in Hungary. The decisive majority of this quantity is harvested from feral plants. The area of elderberry plantations is only 150-180 ha in spite of the fact that it would be possible to produce this valuable fruit on larger surface if suitable watering system were applied. The fruit of elderberry is important from the aspect of food industry. The goal of present study is promoting the effective irrigation of elder berry plantation. The experiments were carried out in the Experimental Farm of the University for Horticulture and Food Industry in Szigetcsép from 1989. The measuring of the water demand of elderberry using the heat pulse method was started in 1996. The measurement of the sap-flow in the trunk is a new element of phyto-climate researches. The development of the equipment was started in 1991 and improvement of the method is still going on. In this phase, first of all the connections between sap-flow velocity and meteorological data were investigated. Summarising the experiences of the trials it can be announced that: (1) The water circulation of elder plants principally depends on the conditions of atmosphere. It is barely sensitive to the water content of the soil. (2) The transpiration intensity reacts sensitively to the change of meteorological conditions. (3) The changing rate of the transpiration coefficient is particularly large in certain intervals of the meteorological elements.

  13. Using Naturally Occurring Radionuclides To Determine Drinking Water Age in a Community Water System.

    PubMed

    Waples, James T; Bordewyk, Jason K; Knesting, Kristina M; Orlandini, Kent A

    2015-08-18

    Drinking water quality in a community water system is closely linked to the age of water from initial treatment to time of delivery. However, water age is difficult to measure with conventional chemical tracers; particularly in stagnant water, where the relationship between disinfectant decay, microbial growth, and water age is poorly understood. Using radionuclides that were naturally present in source water, we found that measured activity ratios of (90)Y/(90)Sr and (234)Th/(238)U in discrete drinking water samples of known age accurately estimated water age up to 9 days old (σest: ± 3.8 h, P < 0.0001, r(2) = 0.998, n = 11) and 25 days old (σest: ± 13.3 h, P < 0.0001, r(2) = 0.996, n = 12), respectively. Moreover, (90)Y-derived water ages in a community water system (6.8 × 10(4) m(3) d(-1) capacity) were generally consistent with water ages derived from an extended period simulation model. Radionuclides differ from conventional chemical tracers in that they are ubiquitous in distribution mains and connected premise plumbing. The ability to measure both water age and an analyte (e.g., chemical or microbe) in any water sample at any time allows for new insight into factors that control drinking water quality.

  14. Using naturally occurring radionuclides to determine drinking water age in a community water system

    DOE PAGES

    Waples, James T.; Bordewyk, Jason K.; Knesting, Kristina M.; ...

    2015-07-22

    Drinking water quality in a community water system is closely linked to the age of water from initial treatment to time of delivery. However, water age is difficult to measure with conventional chemical tracers; particularly in stagnant water, where the relationship between disinfectant decay, microbial growth, and water age is poorly understood. Using radionuclides that were naturally present in source water, we found that measured activity ratios of 90Y/90Sr and 234Th/238U in discrete drinking water samples of known age accurately estimated water age up to 9 days old (σest: ± 3.8 h, P < 0.0001, r2 = 0.998, n =more » 11) and 25 days old (σest: ± 13.3 h, P < 0.0001, r2 = 0.996, n = 12), respectively. Moreover, 90Y-derived water ages in a community water system (6.8 × 104 m3 d–1 capacity) were generally consistent with water ages derived from an extended period simulation model. Radionuclides differ from conventional chemical tracers in that they are ubiquitous in distribution mains and connected premise plumbing. The ability to measure both water age and an analyte (e.g., chemical or microbe) in any water sample at any time allows for new insight into factors that control drinking water quality.« less

  15. Lagoon Seepage Testing Procedures for Central Facilities Area (CFA) Sewage Lagoons at Idaho National Laboratory Butte County, Idaho April 2014

    SciTech Connect

    Alan Giesbrecht

    2014-05-01

    The lagoon seepage testing procedures are documented herein as required by the Wastewater Rules (IDAPA 58.01.16.493). The Wastewater Rules and Wastewater Reuse Permit LA-000141-03 require that the procedure used for performing a seepage test be approved by IDEQ prior to conducting the seepage test. The procedures described herein are based on a seepage testing plan that was developed by J-U-B ENGINEERS, Inc. (J-U-B) and has been accepted by several IDEQ offices for lagoons in Idaho.

  16. Precise determination of water exchanges on a mineral surface

    SciTech Connect

    Stack, Andrew G.; Borreguero, Jose M.; Prisk, Timothy R.; Mamontov, Eugene; Wang, Hsiu-Wen

    2016-10-03

    Solvent exchanges on solid surfaces and dissolved ions are a fundamental property important for understanding chemical reactions, but the rates of fast exchanges are poorly constrained. In this paper, we probed the diffusional motions of water adsorbed onto nanoparticles of the mineral barite (BaSO4) using quasi-elastic neutron scattering (QENS) and classical molecular dynamics (MD) to reveal the complex dynamics of water exchange along mineral surfaces. QENS data as a function of temperature and momentum transfer (Q) were fit using scattering functions derived from MD trajectories. The simulations reproduce the dynamics measured in the experiments at ambient temperatures, but as temperature is lowered the simulations overestimate slower motions. Decomposition of the MD-computed QENS intensity into contributions from adsorbed and unbound water shows that the majority of the signal arises from adsorbed species, although the dynamics of unbound water cannot be dismissed. The mean residence times of water on each of the four surface sites present on the barite {001} were calculated using MD: at room temperature the low barium site is 194 ps, whereas the high barium site contains two distributions of motions at 84 and 2.5 ps. These contrast to 13 ps residence time on both sulfate sites, with an additional surface diffusion exchange of 66 ps. Surface exchanges are similar to those of the aqueous ions calculated using the same force field: Baaq2+ is 208 ps and SO4aq2- is 5.8 ps. Finally, this work demonstrates how MD can be a reliable method to deconvolute solvent exchange reactions when quantitatively validated by QENS measurements.

  17. Precise determination of water exchanges on a mineral surface

    DOE PAGES

    Stack, Andrew G.; Borreguero, Jose M.; Prisk, Timothy R.; ...

    2016-10-03

    Solvent exchanges on solid surfaces and dissolved ions are a fundamental property important for understanding chemical reactions, but the rates of fast exchanges are poorly constrained. In this paper, we probed the diffusional motions of water adsorbed onto nanoparticles of the mineral barite (BaSO4) using quasi-elastic neutron scattering (QENS) and classical molecular dynamics (MD) to reveal the complex dynamics of water exchange along mineral surfaces. QENS data as a function of temperature and momentum transfer (Q) were fit using scattering functions derived from MD trajectories. The simulations reproduce the dynamics measured in the experiments at ambient temperatures, but as temperaturemore » is lowered the simulations overestimate slower motions. Decomposition of the MD-computed QENS intensity into contributions from adsorbed and unbound water shows that the majority of the signal arises from adsorbed species, although the dynamics of unbound water cannot be dismissed. The mean residence times of water on each of the four surface sites present on the barite {001} were calculated using MD: at room temperature the low barium site is 194 ps, whereas the high barium site contains two distributions of motions at 84 and 2.5 ps. These contrast to 13 ps residence time on both sulfate sites, with an additional surface diffusion exchange of 66 ps. Surface exchanges are similar to those of the aqueous ions calculated using the same force field: Baaq2+ is 208 ps and SO4aq2- is 5.8 ps. Finally, this work demonstrates how MD can be a reliable method to deconvolute solvent exchange reactions when quantitatively validated by QENS measurements.« less

  18. Determination of water quality index by fuzzy logic approach: a case of ground water in an Indian town.

    PubMed

    Jinturkar, A M; Deshmukh, S S; Agarkar, S V; Chavhan, G R

    2010-01-01

    The paper proposes fuzzy logic model that deals with the physico-chemical water analysis of ground water of Chikhli town for determination of Water Quality Index (WQI). The study was carried by collection of ground water samples from about eleven hand pumps located in this town. Ground water quality is studied by systematic collection and analysis of samples. The fuzzy logic is used for the deciding the water quality index on the basis of which, water quality rankings are given to determine the quality of water. The Water Quality Index presented here is a unitless number ranging from 1 to 10. A higher number is indicative of better water quality. Around 81% of samples were found suitable for drinking purpose. It is also observed that all the parameters fall within the permissible limits laid by WHO, ISI, and ICMR, except Total Hardness, Calcium and Magnesium. The quality parameters were compared with standards laid by the World Health Organization (WHO), Indian Standards Institute (ISI) and Indian Council of Medical Research (ICMR) for drinking water quality.

  19. Risk factors and monitoring for water quality to determine best management practices for splash parks.

    PubMed

    de Man, H; Leenen, E J T M; van Knapen, F; de Roda Husman, A M

    2014-09-01

    Splash parks have been associated with infectious disease outbreaks as a result of exposure to poor water quality. To be able to protect public health, risk factors were identified that determine poor water quality. Samples were taken at seven splash parks where operators were willing to participate in the study. Higher concentrations of Escherichia coli were measured in water of splash parks filled with rainwater or surface water as compared with sites filled with tap water, independent of routine inspection intervals and employed disinfection. Management practices to prevent fecal contamination and guarantee maintaining good water quality at splash parks should include selection of source water of acceptable quality.

  20. Seepage study of the South Bend, Richfield, and Vermillion Canals, Sevier County, Utah

    USGS Publications Warehouse

    Herbert, L.R.; Smith, G.J.

    1989-01-01

    A seepage investigation was made in 1987 on selected reaches of the South Bend, Richfield, and Vermillion Canals in Sevier County, Utah, to determine gains or losses in discharge.  Fluctuations in discharge were adjusted using information from stage recorders operated at selected locations during each set of discharge measurements. The investigation showed a net gain of 0.2 cubic foot per second in the South Bend canal: the upper reach gained 1.5 cubic feet per second, the two middle reaches together lost 2.5 cubic feet per second, and the lower reach gained 1.2 cubic feet per second.  The Richfield Canal showed a net loss of 2.4 cubic feet per second: the two upper reaches together lost 4.4 cubic feet per second and the two lower reaches together gained 2.0 cubic feet per second.  The Vermillion canal showed a net loss of 0.2 cubic foot per second: the upper reach gained 2.3 cubic feet per second and the lower reach lost 2.5 cubic feet per second.

  1. Standard reference water samples for rare earth element determinations

    USGS Publications Warehouse

    Verplanck, P.L.; Antweiler, R.C.; Nordstrom, D.K.; Taylor, H.E.

    2001-01-01

    Standard reference water samples (SRWS) were collected from two mine sites, one near Ophir, CO, USA and the other near Redding, CA, USA. The samples were filtered, preserved, and analyzed for rare earth element (REE) concentrations (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) by inductively coupled plasma-mass spectrometry (ICP-MS). These two samples were acid mine waters with elevated concentrations of REEs (0.45-161 ??g/1). Seventeen international laboratories participated in a 'round-robin' chemical analysis program, which made it possible to evaluate the data by robust statistical procedures that are insensitive to outliers. The resulting most probable values are reported. Ten to 15 of the participants also reported values for Ba, Y, and Sc. Field parameters, major ion, and other trace element concentrations, not subject to statistical evaluation, are provided.

  2. Changes in the saltwater interface corresponding to the installation of a seepage barrier near Lake Okeechobee, Florida

    USGS Publications Warehouse

    Prinos, Scott T.; Valderrama, Robert

    2015-01-01

    At five of the monitoring-well cluster locations, a long-screened well was also installed for monitoring and comparison purposes. These long-screened wells are 160 to 200 ft deep, and have open intervals ranging from 145 to 185 ft in length. Water samples were collected at depth intervals of about 5 to 10 ft, using 3-ft-long straddle packers to isolate each sampling interval. The results of monitoring conducted using these long-screened interval wells were generally too variable to identify any changes that might be associated with the seepage barrier. Samples from one of these long-screened interval wells failed to detect the saltwater interface evident in samples and TSEMIL datasets from a collocated well cluster. This failure may have been caused by downward flow of freshwater from above the saltwater interface in the well bore.

  3. Numerical modeling of subsurface radioactive solute transport from waste seepage ponds at the Idaho National Engineering Laboratory

    USGS Publications Warehouse

    Robertson, John B.

    1976-01-01

    Aqueous chemical and low-level radioactive effluents have been disposed to seepage ponds since 1952 at the Idaho National Engineering Laboratory. The solutions percolate toward the Snake River Plain aquifer (135 m below) through interlayered basalts and unconsolidated sediments and an extensive zone of ground water perched on a sedimentary layer about 40 m beneath the ponds. A three-segment numerical model was developed to simulate the system, including effects of convection, hydrodynamic dispersion, radioactive decay, and adsorption. Simulated hydraulics and solute migration patterns for all segments agree adequately with the available field data. The model can be used to project subsurface distributions of waste solutes under a variety of assumed conditions for the future. Although chloride and tritium reached the aquifer several years ago, the model analysis suggests that the more easily sorbed solutes, such as cesium-137 and strontium-90, would not reach the aquifer in detectable concentrations within 150 years for the conditions assumed. (Woodard-USGS)

  4. Analytical Methods for Determining Nitroguanidine in Soil and Water

    DTIC Science & Technology

    1989-11-01

    1 2. Chromiatogram of aqueous nitroguanidine on a RP18 /cation exchange column eluted with 1.5 mL/min of...are analyzed. This report outlines the development Separations were achieved on a mixed mode of a High Performance Liquid Chromatographic RP18 ...water samples. Separation is achieved Retention time for nitroguanidine was 4.4 minutes. using a mixed mode RP18 /cation exchange col- Figure 2 shows

  5. Determination of antibiotic residues in manure, soil, and surface waters

    USGS Publications Warehouse

    Christian, T.; Schneider, R.J.; Farber, H.A.; Skutlarek, D.; Meyer, M.T.; Goldbach, H.E.

    2003-01-01

    In the last years more and more often detections of antimicrobially active compounds ("antibiotics") in surface waters have been reported. As a possible input pathway in most cases municipal sewage has been discussed. But as an input from the realm of agriculture is conceivable as well, in this study it should be investigated if an input can occur via the pathway application of liquid manure on fields with the subsequent mechanisms surface run-off/interflow, leaching, and drift. For this purpose a series of surface waters, soils, and liquid manures from North Rhine-Westphalia (Northwestern Germany) were sampled and analyzed for up to 29 compounds by HPLC-MS/MS. In each of the surface waters antibiotics could be detected. The highest concentrations were found in samples from spring (300 ng/L of erythromycin). Some of the substances detected (e.g., tylosin), as well as characteristics in the landscape suggest an input from agriculture in some particular cases. In the investigation of different liquid manure samples by a fast immunoassay method sulfadimidine could be detected in the range of 1...2 mg/kg. Soil that had been fertilized with this liquid manure showed a content of sulfadimidine extractable by accelerated solvent extraction (ASE) of 15 ??g/kg dry weight even 7 months after the application. This indicates the high stability of some antibiotics in manure and soil.

  6. Determinants of drinking arsenic-contaminated tubewell water in Bangladesh.

    PubMed

    Khan, M M H; Aklimunnessa, Khandoker; Kabir, M; Mori, Mitsuru

    2007-09-01

    Bangladesh has already experienced the biggest catastrophe in the world due to arsenic contamination of drinking water. This study investigates the association of drinking arsenic-contaminated water (DACW) with both personal and household characteristics of 9116 household respondents using the household data of the Bangladesh Demographic and Health Survey (BDHS) 2004. Here DACW means that arsenic level in the drinking water is greater than the permissible limit (50 microg/l) of Bangladesh. The overall rate of DACW was 7.9%. It was found to be significantly associated with education, currently working, and division of Bangladesh, either by cross tabulation or multivariate logistic regression analyses or both. Similarly, household characteristics -- namely television, bicycle, materials of the wall and floor, total family members, number of sleeping rooms, and availability of foods -- were significantly associated in bivariate analyses. Many household characteristics -- namely electricity, television, wall and floor materials, and number of sleeping rooms -- revealed significant association in the logistic regression analysis when adjusted for age, education and division. This study indicates that respondents from Chittagong division and lower socio-economic groups (indicated by household characteristics) are at significantly higher risk of DACW. These findings should be taken into account during the planning of future intervention activities in Bangladesh.

  7. Evaluation of seepage and acid generation potential from evaporation ponds, Iron Duke Pyrite Mine, Mazowe Valley, Zimbabwe

    NASA Astrophysics Data System (ADS)

    Ravengai, Seedwel; Owen, Richard; Love, David

    Iron Duke Pyrite Mine lies in the Mazowe Valley of northern Zimbabwe. Several urban areas and commercial farmers are major water users in the catchment. Accordingly, managing the impact of mining operations on water quality in the Mazowe Valley must be a major priority for sustainable development in this area. The mine disposes of its waste water via evaporation ponds. Some of the water in the ponds evaporates and some is lost through seepage to groundwater. Results of a water budget analysis of the ponds showed that 160.5 m 3 per day of acidic effluent with a pH of 2 and elevated levels of iron and sulphate was being lost through seepage. As the wastewater evaporates, the secondary minerals melanterite and hexahydrite precipitate. The solid material in the pond was found to contain 20% iron and 14% sulphate, which is far more than was found dissolved within the pond water. Despite this, the pond water is undersaturated with respect to both iron and sulphate. Acid generation tests on the solid material in the pond indicate a minimum of 540,000 mol and a maximum of 1,610,309 mol of acid are generated. The variation can be related to exposure to oxygen: material near the edges of the pond is more exposed to oxygen and has already reacted further than material from the centre of the pond; accordingly less acid can be generated. The acidity generated by the pond is due to the unreacted pyrite that is found in fine particles suspended in mine waters. Based on these results, between 20 and 60 metric tonnes of lime are required for complete neutralisation of the sediments in the pond. Although the ponds were decommissioned after the conclusion of this study, it is necessary to prevent formation of further acid mine drainage from existing sediments in the evaporation pond. This could be done by the use of reactive covers, whose compositions affect the chemistry of infiltrating water. A good reactive cover could be constructed from lime, overlain by topsoil rich in organic

  8. 18 CFR 430.7 - Determination of protected areas and restriction on water use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... protected areas and restriction on water use. 430.7 Section 430.7 Conservation of Power and Water Resources... Determination of protected areas and restriction on water use. In consideration of the foregoing facts and for... a protected area within the meaning and for the purpose of Article 10 of the Delaware River...

  9. Determining the Water Bootprint of the Army’s Supply Chain

    DTIC Science & Technology

    2011-05-01

    Coca - Cola – – Product Packaging – Product Ingredients – Plant Operations • Study concluded that approximately 35 liters of water are used to produce...bootprint of a product is the sum of the water footprints of all the process steps • Coca - Cola determined the water footprint of its 0.5 liter bottle of

  10. Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilization

    NASA Astrophysics Data System (ADS)

    Iverson, Richard M.; Major, Jon J.

    1986-10-01

    Insight for understanding the effect of groundwater flow on the potential for hillslope failure and liquefaction is provided by a novel limit-equilibrium analysis of infinite slopes with steady, uniform Darcian seepage of arbitrary magnitude and direction. Normalization of the limit-equilibrium solution shows that three dimensionless parameters govern completely the Coulomb failure potential of saturated, cohesionless, infinite homogeneous hillslopes: (1) the ratio of seepage force magnitude to gravitational body force magnitude; (2) the angle θ - Φ, where θ is the surface slope angle and Φ is the angle of internal friction of the soil; and (3) the angle λ + Φ, where λ is the angle of the seepage vector measured with respect to an outward-directed surface-normal vector. An additional dimensionless parameter affects the solution if soil cohesion is included in the analysis. Representation of the normalized solution as a single family of curves shows that minimum slope stability universally occurs when the seepage direction is given by λ = 90° - Φ. It also shows that for some upward seepage conditions, slope stability is limited by static liquefaction rather than by Coulomb failure. Close association between these liquefaction conditions and certain Coulomb failure conditions indicates that slope failure in such instances could be responsible for nearly spontaneous mobilization of destructive flowing soil masses on hillslopes.

  11. The Determination of Trace Metals in Saline Waters and Biological Tissues Using the Heated Graphite Atomizer

    NASA Technical Reports Server (NTRS)

    Segar, D. A.

    1971-01-01

    A selective, volatalization technique utilizing the heated graphite atomizer atomic absorption technique has been developed for the analysis of iron in sea water. A similar technique may be used to determine vanadium, copper, nickel and cobalt in saline waters when their concentrations are higher than those normally encountered'in unpolluted sea waters. A preliminary solvent extraction using ammonium pyrolidine dithiocarbamate and methyl iso-butyl ketone permits the determination of a number of elements including iron, copper, zinc, nickel, cobalt and lead in sea water. The heated graphite atomized technique has also been applied to the determination of a range of trace transition elements in marine plant and animal tissues.

  12. QPCR Determined Fecal Indicator Bacterial Densities in Marine Waters from Two Recreational Beaches

    EPA Science Inventory

    The use of real-time qPCR to determine fecal indicator bacteria (FIB) densities is currently being investigated by the U.S. EPA. The present recreational water quality guidelines, based on culturable FIB, prevent same day determinations of water quality whereas results from the ...

  13. Determination of Vinyl Chloride at ug/l. Level in Water by Gas Chromatography

    ERIC Educational Resources Information Center

    Bellar, Thomas A.; And Others

    1976-01-01

    A quantitative method for the determination of vinyl chloride in water is presented. Vinyl chloride is transfered to the gas phase by bubbling inert gas through the water. After concentration on silica gel or Carbosieve-B, determination is by gas chromatography. Confirmation of vinyl chloride is by gas chromatography-mass spectrometry. (Author/BT)

  14. THE NEED FOR SPEED-RAPID METHODOLOGIES TO DETERMINE BATHING BEACH WATER QUALITY

    EPA Science Inventory

    Current methods for determining fecal contamination of recreational waters rely on the culture of bacterial indicators and require at least 24 hours to determine whether the water is unsafe for use. By the time monitoring results are available, exposures have already occurred. N...

  15. Peritidal stromatolites at the convergence of groundwater seepage and marine incursion: Patterns of salinity, temperature and nutrient variability

    NASA Astrophysics Data System (ADS)

    Rishworth, Gavin M.; Perissinotto, Renzo; Bornman, Thomas G.; Lemley, Daniel A.

    2017-03-01

    Living peritidal stromatolites forming at the interface of coastal groundwater seepage and regular marine input are known from only a few locations globally, including South Africa, Western Australia and Northern Ireland. In contrast to modern stromatolites from exclusively fresh or marine waters, which persist due to high calcium carbonate saturation states or hypersaline and erosive conditions (which exclude organisms that might disrupt or out-compete the stromatolite-forming benthic microalgae), the factors supporting stromatolite formation at peritidal locations have not been well-documented. Therefore, the aim of this study was to investigate the fine-scale physico-chemical parameters in terms of pool temperature, salinity and nutrient dynamics at three representative sites along the coastline near Port Elizabeth, South Africa. These parameters were assessed with reference to potential physical, meteorological and ocean drivers using a linear or linear mixed-effects modelling approach. Results demonstrate that nutrient inputs into the pools supporting the majority of stromatolite accretion (barrage pools) are driven by groundwater seepage site-specific properties related to anthropogenic occupation (dissolved inorganic nitrogen; DIN) as well as marine water incursion (dissolved inorganic phosphorus; DIP). Pool temperature is a function of seasonal ambient variability while salinity reflects regular state shifts from fresh to marine conditions, which are related to tidal amplitude and swell height. The regular marine incursions likely promote benthic primary biomass in the phosphorus-limited stromatolite pools, as well as preclude organisms which might otherwise outcompete or disrupt the stromatolite microalgae due to intolerances to extreme ( 1.5 to ≥ 30) salinity variability.

  16. Determining the water age of Lake Taihu during the water transfer from Yangtze River, China

    NASA Astrophysics Data System (ADS)

    Li, Yiping; Acharya, Kumud; Zhu, Jianting; Yu, Zhongbo

    2010-05-01

    To improve water quality and alleviate the eutrophication problem for Lake Taihu, the third largest shallow lake in China, water transfer project from Yangtze River, was initiated to dilute the polluted water and export pollutants out of the lake in 2002. The impact of water transfer on transport processes of dissolved substance in the lake is studied by using the concept of water age using a three-dimensional numerical model, Environmental Fluid dynamic Code (EFDC). Influences of inflow tributaries and wind forcing on water age distribution are investigated. Model results show that the effect of water transfer on transport processes in the lake is strongly affected by hydrodynamic conditions induced by wind and inflow/outflow tributaries. Water age in Lake Taihu has highly spatial and temporal heterogeneity, with the mean water age of approximately 130 days in summer and 230 days in other seasons during the simulation year. Southeastly wind, the dominant wind direction in summer, could improve eastern areas of the lake which provide drinking water source and Meiliang Bay, the most polluted bay in the lake. The most efficient flow discharge of transferred water for diluting the lake could be approximately 100 m3/s while considering benefit/cost ratio. Additionally, the water transfer project just minor effects on parts of the lake rather than the entire lake, unless nutrient concentrations in the transferred water are reduced to a reasonable level. This study provides useful information for better understanding the complex hydrodynamic and mass transport processes in the lake, which is important for developing and implementing effective lake management strategies. Keywords: water transfer; water age; EFDC; Lake Taihu; Yangtze River

  17. Using naturally occurring radionuclides to determine drinking water age in a community water system

    SciTech Connect

    Waples, James T.; Bordewyk, Jason K.; Knesting, Kristina M.; Orlandini, Kent A.

    2015-07-22

    Drinking water quality in a community water system is closely linked to the age of water from initial treatment to time of delivery. However, water age is difficult to measure with conventional chemical tracers; particularly in stagnant water, where the relationship between disinfectant decay, microbial growth, and water age is poorly understood. Using radionuclides that were naturally present in source water, we found that measured activity ratios of 90Y/90Sr and 234Th/238U in discrete drinking water samples of known age accurately estimated water age up to 9 days old (σest: ± 3.8 h, P < 0.0001, r2 = 0.998, n = 11) and 25 days old (σest: ± 13.3 h, P < 0.0001, r2 = 0.996, n = 12), respectively. Moreover, 90Y-derived water ages in a community water system (6.8 × 104 m3 d–1 capacity) were generally consistent with water ages derived from an extended period simulation model. Radionuclides differ from conventional chemical tracers in that they are ubiquitous in distribution mains and connected premise plumbing. The ability to measure both water age and an analyte (e.g., chemical or microbe) in any water sample at any time allows for new insight into factors that control drinking water quality.

  18. Passive acoustic derived bubble flux and applications to natural gas seepage in the Mackenzie Delta, NWT, Canada and Coal Oil Point, CA

    NASA Astrophysics Data System (ADS)

    Culling, D.; Leifer, I.; Dallimore, S.; Alcala, K.

    2012-12-01

    Methane is a prominent greenhouse gas that escapes naturally from thermogenic reservoirs as seepage from marine and lacustrine biogenic sources as bubble ebullition. Geologic methane emissions are critically important contributors to the global methane budget however, few quantitative flux measurements are available for shallow waters. This gap in knowledge is critical as in these settings gas can easily transit as bubbles through the water column and directly influence global atmospheric budgets. Video and active acoustic (sonar) measurements of bubble flux have spatial limitations requiring predictable bubble emission location. Passive acoustics are less affected by these limitations, in addition, they can provide data in water too shallow for effective sonar bubble observations. Lab tests were undertaken to quantify the acoustic signature of bubbles formed in non-cohesive sediments. specifically focusing on mechanisms that complicate interpretation of acoustic data. Lab tests then were compared to field data to provide measurement calibration/validation. The principles behind the acoustic analysis method are based on the Minnaert equation, which relates a bubble radius and acoustic frequency. Bubble size and the resultant acoustic frequency from known flows and capillary tube diameters are well documented; however changing sediment pathways adds to the complexity of bubble formation and the resultant bubble acoustic signal. These complex signals were investigated in a lab tank with a thick, cohesive fine-grained sediment bed, through which bubbles produced by a syringe pump migrated to the sediment-water interface. Then, the resultant bubbles were diverted into clear water and measured from high speed, high definition video, while the acoustic signature of bubble formation was recorded concurrently by a hydrophone. Bubble formation is influenced by currents, which shifts the acoustical signal towards a higher frequency with a more complex pattern than the

  19. Algorithm for Determining the Effectiveness of Water Conservation Measures.

    DTIC Science & Technology

    1984-03-01

    Turnovsky Bruner Grima Wong Ridge, R. Leone, Ginn 1978 Miami, FL cross-sectional -1.33 dept. stores -0.89 grocery stores -0.14 to -0.30...Division of Building Technology, November 1982. M 7-2 _ ’ 21. Bruner , J.M. An Analysis of Municipal Water Demand in the Phoenix Metropolitan Area...Washington, D.C., June 1966. 89. Linaweaver, F.P. Jr., John C. Geyer, and Jerome B. Wolff. "Summary Report on the Research Project." JAWWA, 59, No

  20. Determination of water retention in stratified porous materials

    USGS Publications Warehouse

    Constantz, J.

    1995-01-01

    Predicted and measured water-retention values, ??(??), were compared for repacked, stratified core samples consisting of either a sand with a stone-bearing layer or a sand with a clay loam layer in various spatial orientations. Stratified core samples were packed in submersible pressure outflow cells, then water-retention measurements were performed between matric potentials, ??, of 0 to -100 kPa. Predictions of ??(??) were based on a simple volume-averaging model using estimates of the relative fraction and ??(??) values of each textural component within a stratified sample. In general, predicted ??(??) curves resembled measured curves well, except at higher saturations in a sample consisting of a clay loam layer over a sand layer. In this case, the model averaged the air-entry of both materials, while the air-entry of the sample was controlled by the clay loam in contact with the cell's air-pressure inlet. In situ, avenues for air-entry generally exist around clay layers, so that the model should adequately predict air-entry for stratified formations regardless of spatial orientation of fine versus coarse layers. Agreement between measured and predicted volumetric water contents, ??, was variable though encouraging, with mean differences between measured and predicted ?? values in the range of 10%. Differences in ?? of this magnitude are expected due to variability in pore structure between samples, and do not indicate inherent problems with the volume averaging model. This suggets that explicit modeling of stratified formations through detailed characterization of the stratigraphy has the potential of yielding accurate ??(??) values. However, hydraulic-equilibration times were distinctly different for each variation in spatial orientation of textural layering, indicating that transient behavior during drainage in stratified formations is highly sensitive to the stratigraphic sequence of textural components, as well as the volume fraction of each textural

  1. Group methods of determining surfactants in water (review)

    SciTech Connect

    Subbotina, E.I.; Dedkov, Yu.M.

    1988-01-01

    In recent years new and promising methods for the determination of industrial surfactant waste migration and concentration in the hydrosphere have been developed. These methods include different forms of chromatography, ion selective electrode analysis, titration, and solvent extraction. This article reviews the application and usefulness of each of these methods in the analysis of various surfactants. The methods of chromatography reviewed include liquid column, thin layer, and ion exchange.

  2. Direct absorbed dose to water determination based on water calorimetry in scanning proton beam delivery

    SciTech Connect

    Sarfehnia, A.; Clasie, B.; Chung, E.; Lu, H. M.; Flanz, J.; Cascio, E.; Engelsman, M.; Paganetti, H.; Seuntjens, J.

    2010-07-15

    Purpose: The aim of this manuscript is to describe the direct measurement of absolute absorbed dose to water in a scanned proton radiotherapy beam using a water calorimeter primary standard. Methods: The McGill water calorimeter, which has been validated in photon and electron beams as well as in HDR {sup 192}Ir brachytherapy, was used to measure the absorbed dose to water in double scattering and scanning proton irradiations. The measurements were made at the Massachusetts General Hospital proton radiotherapy facility. The correction factors in water calorimetry were numerically calculated and various parameters affecting their magnitude and uncertainty were studied. The absorbed dose to water was compared to that obtained using an Exradin T1 Chamber based on the IAEA TRS-398 protocol. Results: The overall 1-sigma uncertainty on absorbed dose to water amounts to 0.4% and 0.6% in scattered and scanned proton water calorimetry, respectively. This compares to an overall uncertainty of 1.9% for currently accepted IAEA TRS-398 reference absorbed dose measurement protocol. The absorbed dose from water calorimetry agrees with the results from TRS-398 well to within 1-sigma uncertainty. Conclusions: This work demonstrates that a primary absorbed dose standard based on water calorimetry is feasible in scattered and scanned proton beams.

  3. Formation of Box Canyon, Idaho, by megaflood: implications for seepage erosion on Earth and Mars.

    PubMed

    Lamb, Michael P; Dietrich, William E; Aciego, Sarah M; Depaolo, Donald J; Manga, Michael

    2008-05-23

    Amphitheater-headed canyons have been used as diagnostic indicators of erosion by groundwater seepage, which has important implications for landscape evolution on Earth and astrobiology on Mars. Of perhaps any canyon studied, Box Canyon, Idaho, most strongly meets the proposed morphologic criteria for groundwater sapping because it is incised into a basaltic plain with no drainage network upstream, and approximately 10 cubic meters per second of seepage emanates from its vertical headwall. However, sediment transport constraints, 4He and 14C dates, plunge pools, and scoured rock indicate that a megaflood (greater than 220 cubic meters per second) carved the canyon about 45,000 years ago. These results add to a growing recognition of Quaternary catastrophic flooding in the American northwest, and may imply that similar features on Mars also formed by floods rather than seepage erosion.

  4. Determining water reservoir characteristics with global elevation data

    NASA Astrophysics Data System (ADS)

    Bemmelen, C. W. T.; Mann, M.; Ridder, M. P.; Rutten, M. M.; Giesen, N. C.

    2016-11-01

    Quantification of human impact on water, sediment, and nutrient fluxes at the global scale demands characterization of reservoirs with an accuracy that is presently unavailable. This letter presents a new method, based on virtual dam placement, to make accurate estimations of area-volume relationships of large reservoirs, using solely readily available elevation data. The new method is based on regional similarity of area-volume relationships. The essence of the method is that virtual reservoirs are created in the vicinity of an existing reservoir to derive area-volume relationships for the existing reservoir. The derived area-volume relationships reproduced in situ bathymetric data well. An intercomparison for twelve reservoirs resulted in an average R2 = 0.93. This is a significant improvement on estimates using the best existing global regression model, which gives R2 = 0.54 for the same set of reservoirs.

  5. Electrochemical determination of pharmaceuticals in spiked water samples.

    PubMed

    Ambrosi, Adriano; Antiochia, Riccarda; Campanella, Luigi; Dragone, Roberto; Lavagnini, Irma

    2005-07-15

    The electrochemical behaviour of acidic and neutral pharmaceutical active compounds (PhACs) was studied by cyclic voltammetry and pulse voltammetric techniques on mercury, carbon nanotube paste, carbon paste and gold electrodes. The best results, in terms of sensitivity, linearity range and detection limits, were obtained by differential pulse voltammetry (DPV) for ofloxacin (LOD 5.2 microM), differential pulse polarography (DPP) for clofibric acid (LOD 4.7 microM) and normal pulse voltammetry (NPV) for diclofenac (LOD 0.8 microM) and propranolol (LOD 0.5 microM). An enrichment step of approximately two orders of magnitude was performed by a solid-phase extraction procedure (SPE) in order to concentrate the samples. The developed method was optimized and tested on spiked river water samples.

  6. Techniques for determining total body water using deuterium oxide

    NASA Technical Reports Server (NTRS)

    Bishop, Phillip A.

    1990-01-01

    The measurement of total body water (TBW) is fundamental to the study of body fluid changes consequent to microgravity exposure or treatment with microgravity countermeasures. Often, the use of radioactive isotopes is prohibited for safety or other reasons. It was selected and implemented for use by some Johnson Space Center (JCS) laboratories, which permitted serial measurements over a 14 day period which was accurate enough to serve as a criterion method for validating new techniques. These requirements resulted in the selection of deuterium oxide dilution as the method of choice for TBW measurement. The development of this technique at JSC is reviewed. The recommended dosage, body fluid sampling techniques, and deuterium assay options are described.

  7. Determination of pentachlorophenol in water and aquifer sediments by high-performance liquid chromatography

    USGS Publications Warehouse

    Goerlitz, D.F.

    1981-01-01

    Methods for the determination of pentachlorophenol (PCP) in water and aquifer sediments are presented. Reverse-phase high-performance liquid chromotography employing ion suppression and gradient elution is used. PCP can be determined directly in water at a lower limit of detection Of 0.2 micrograms per liter. For extracts of sediment, PCP can be determined to a lower limit of 1.0 micrograms per kilogram.

  8. Determination of water absorption and water holding capacities of different soil mixtures with MINIDRAIN system to enhance the plant growth

    NASA Astrophysics Data System (ADS)

    Sudan Acharya, Madhu; Rauchecker, Markus; Wu, Wei

    2014-05-01

    Soil water holding capacity is the amount of water that a given soil can hold against the force of gravity. Soil texture and organic matter are the key components that determine soil water holding capacity. Soils with smaller particle sizes, such as silt and clay have larger surface area can hold more water compared to sand which has large particle sizes which results in smaller surface area. A study report showed that 1% increase in soil humus will result in a 4% increase in stored soil water (Morris, 2004) and 1 part humus holds 4 parts of water (Wheeler and Ward, 1998). Therefore, the more humus that can be added to the soil, the greater the water holding capacity of the soil. As the level of organic matter increases in a soil, the water holding capacity also increases due to the affinity of organic matter for water. The water holding capacity of the soil is determined by the amount of water held in the soil sample vs. the dry weight of the sample. MINIDRAIN is a patented system made of geo-fabric (fleece) or combination of geosynthetics and humus. MINIDRAIN and vegetation nets developed by the company ÖKO-TEX (Linz, Austria) will improve the distribution of water and air in the soils, increase the growth of vegetation and reduce the soil erosion. Depending on the physical configuration, there are four different combinations of MINIDRAIN systems developed by ÖKO-TEX. a) Geotextile (fleece) strips of different sizes (e.g. 5x10x250 mm) b) Net formed strips (drainage nets) of different sizes c) Multilayer geotextile mats with humus, seeds or compost of different sizes (e.g. 10x30x200 mm) d) Multilayer geotextile net formed mats with humus, seeds or compost This paper describes the experimental results of the water absorption and water holding capacity of different forms of MINIDRAIN under different soil mixes. In this experiment, potting soil, coarse sand and LECA (Light weight clay aggregates) balls are mixed with different proportion of MINIDRAIN systems and

  9. Measuring the erodibility of cohesive soils influenced by seepage forces using a laboratory jet erosion test device

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seepage influences the erodibility of streambanks, streambeds, dams, and embankments. However, the interaction between fluvial and seepage mechanisms in cohesive soils is still poorly understood. Usually the erosion rate of cohesive soils due to fluvial forces is computed using an excess shear str...

  10. Seepage and Piping through Levees and Dikes using 2D and 3D Modeling Codes

    DTIC Science & Technology

    2016-06-01

    Modeling Codes Co as ta l a nd H yd ra ul ic s La bo ra to ry Hwai-Ping Cheng, Stephen M. England, and Clarissa M. Murray June 2016...Flood & Coastal Storm Damage Reduction Program ERDC/CHL TR-16-6 June 2016 Seepage and Piping through Levees and Dikes Using 2D and 3D Modeling Codes ...TYPE Final Report 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Seepage and Piping through Levees and Dikes using 2D and 3D Modeling Codes

  11. Determination of water in NIST reference material for mineral oils

    PubMed

    Cedergren; Nordmark

    2000-07-15

    The accuracy of the reference concentrations of moisture in electrical insulating oil RM 8506 and lubricating oil RM 8507 (both of mineral type) and specified by the National Institute of Standards and Technology (NIST) as containing 39.7 and 76.8 ppm (w/w) water, respectively, has recently been the subject of debate in this journal. To shed some further light on this controversy, we report in this correspondence results for these oils obtained by two additional methods, one based on specially designed reagents for diaphragm-free Karl Fischer (KF) coulometry and the other based on the concept of stripping at elevated temperature/continuous KF coulometry. A positive interference effect was shown to take place for RM 8506 when the direct coulometric method was used. If the results are corrected for this, the values including six different procedures varied in the range 13.5-15.6 ppm (w/w). For RM 8507, all values were between 42.5 and 47.2 ppm (w/w), which means that the values recommended by NIST for both reference oils using volumetric titration are about twice as high as those obtained with the other techniques. A possible explanation for this discrepancy is presented.

  12. Rapid determination of actinides and (90)Sr in river water.

    PubMed

    Habibi, A; Boulet, B; Gleizes, M; Larivière, D; Cote, G

    2015-07-09

    Nuclear accidents occurred in latest years highlighted the difficulty to achieve, in a short time, the quantification of alpha and beta emitters. Indeed, most of the existing methods, though displaying excellent performances, can be very long, taking up to several weeks for some radioisotopes, such as (90)Sr. This study focuses on alpha and beta radioisotopes which could be accidentally released from nuclear installations and which could be measured by inductively coupled plasma mass spectrometer (ICP-MS). Indeed, a new and rapid separation method was developed for (234,235,236,238)U, (230,232)Th, (239,240)Pu, (237)Np, (241)Am and (90)Sr. The main objective was to minimize the duration of the separation protocol by the development of a unique radiochemical procedure with elution media compatible with ICP-MS measurements. Excellent performances were obtained with spiked river water samples. These performances are characterized by total yields exceeding 80% for all monitored radionuclides, as well as good reproducibility (RSD≤10%, n=12). The proposed radiochemical separation (including counting time) required less than 7h for a batch of 8 samples.

  13. Determining extreme parameter correlation in ground water models.

    USGS Publications Warehouse

    Hill, M.C.; Osterby, O.

    2003-01-01

    In ground water flow system models with hydraulic-head observations but without significant imposed or observed flows, extreme parameter correlation generally exists. As a result, hydraulic conductivity and recharge parameters cannot be uniquely estimated. In complicated problems, such correlation can go undetected even by experienced modelers. Extreme parameter correlation can be detected using parameter correlation coefficients, but their utility depends on the presence of sufficient, but not excessive, numerical imprecision of the sensitivities, such as round-off error. This work investigates the information that can be obtained from parameter correlation coefficients in the presence of different levels of numerical imprecision, and compares it to the information provided by an alternative method called the singular value decomposition (SVD). Results suggest that (1) calculated correlation coefficients with absolute values that round to 1.00 were good indicators of extreme parameter correlation, but smaller values were not necessarily good indicators of lack of correlation and resulting unique parameter estimates; (2) the SVD may be more difficult to interpret than parameter correlation coefficients, but it required sensitivities that were one to two significant digits less accurate than those that required using parameter correlation coefficients; and (3) both the SVD and parameter correlation coefficients identified extremely correlated parameters better when the parameters were more equally sensitive. When the statistical measures fail, parameter correlation can be identified only by the tedious process of executing regression using different sets of starting values, or, in some circumstances, through graphs of the objective function.

  14. Relative water content of Spruce needles determined by the leaf water content index

    NASA Technical Reports Server (NTRS)

    Hunt, E. Raymond, Jr.; Wong, Sam K. S.; Rock, Barrett N.

    1987-01-01

    Leaf relative water content (RWC) is defined as the volume of water in a leaf divided by the volume at full turgor. Using reflectance factors of wavelengths 0.83 micron and 1.6 microns, a Leaf Water Content Index (LWCI) was derived from the Lambert-Beer Law such that LWCI should equal RWC; LWCI was equal to RWC for Picea pungens, Picea rubens, Liquidambar styraciflua, and Quercus agrifolia. Algebraic manipulation shows that R(1.6)/R(0.83) termed the Moisture Stress Index (MSI), is near-linearly correlated to RWC and to the Equivalent Water Thickness (EWT). Five species tested so far had the same relationship between MSI and EWT, but EWT is not a measure of plant water status.

  15. Experimental determination of cavitation thresholds in liquid water and mercury

    SciTech Connect

    Taleyarkhan, R.P.; Gulec, K.; West, C.D.; Haines, J.

    1998-09-01

    It is well-known that fluids (like solids) will break apart or form voids when put under sufficient tension. The present study has been motivated by the need to evaluate the impact of fluid cavitation in spallation neutron source target systems, more specifically for the proposed 1-MW Spallation Neutron Source (SNS) project, which is being designed in collaboration between Oak Ridge National Laboratory (ORNL), Los Alamos National Laboratory, Lawrence Berkeley National Laboratory, Brookhaven National Laboratory, and Argonne National Laboratory. Indeed, results of SNS-specific simulations have indicated that the onset of cavitation could play a very significant role in reducing imposed stresses in structural components of the SNS. In general, the cavitation of fluids is target systems is important to consider for a variety of reasons. Its occurrence can have significant impact on heat transfer, pressure pulse generation, fluid jetting on to structures, surface erosion, stresses induced in enclosures, etc. Therefore, it is important to evaluate the threshold pressure under which the fluid in tension will undergo cavitation. Another major aspect concerns the possible onset of cavitation in an oscillating pressure field; i.e., one would need to know if fluids such as mercury and water will cavitate if the imposed tensile pressure in the fluid is of short duration. If indeed it takes sufficiently long for cavitation bubbles to nucleate, then it would be possible to disregard the complexities involved with addressing cavitation-related issues. This paper provides an overview of preliminary work done to date to derive information on cavitation onset in a relatively static and in a high-frequency environment.

  16. An experimental and theoretical study of the seepage migration of suspended particles with different sizes

    NASA Astrophysics Data System (ADS)

    Bai, Bing; Xu, Tao; Guo, Zhiguang

    2016-12-01

    This study experimentally investigates the effect of particle size, particle concentration and flow velocity on the migration of suspended particles of size 1.02-47 μm in porous media. The results show that at the same flow velocity, the peak values of the breakthrough curves decrease and corresponding pore volumes increase slightly with increasing particles size. The migration velocity of smaller suspended particles is even greater than water flow velocity, which is attributed to the size exclusion effect. With increase of the injected particle concentration, the deposition coefficients of small single particles increase at first and then tend to a steady state or even decrease slightly, explained by the maximum retention concentration. The dispersivity of small particles decreases with increasing velocity. However, at a high flow velocity, the hydrodynamic dispersivity becomes increasingly dominant with the increase of particle size. The deposition coefficients for large-sized particles are higher than those for small-sized particles, which is attributed to considerable mass removal due to straining. An analytical solution, considering the release effect of sorbed particles, is developed to account for the one-dimensional flow and dispersive effect using a source function method, and then three transport parameters—dispersivity, deposition coefficient and release coefficient—are fitted using the experimental results. Finally, suspended-particle migration is predicted by the proposed model for short-time constant-concentration injection and repeated three-pulse injection. Overall, particle size has a significant effect on the seepage migration parameters of suspended particles in porous media such as the particle velocity, dispersivity and deposition coefficient.

  17. H-Area Seepage Basins groundwater monitoring report -- third and fourth quarters 1993. Volume 1

    SciTech Connect

    Butler, C.T.

    1994-03-01

    During the second half of 1993, the groundwater at the H-Area Seepage Basins (HASB) was monitored in compliance with the September 30, 1992, modification of South Carolina Hazardous Waste Permit SC1-890-008-989. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B post-closure care permit application for the H-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control (SCDHEC) in December 1990. Beginning first quarter 1993, the HASB`s Groundwater Protection Standard (GWPS), established in Appendix 3D-A of the cited permit, became the standard for comparison. Historically as well as currently, nitrate, nonvolatile beta, and tritium have been among the primary constituents to exceed standards. Other radionuclides and hazardous constitutents also exceeded the GWPS in the groundwater at the HASB (notably aluminum, iodine-129, strontium-90, technetium-99, and zinc) during the second half of 1993. Elevated constituents were found primarily in Aquifer Zone 2B{sub 2} and in the upper portion of Aquifer Zone 2B{sub 1}. However, constituents exceeding standards also occurred in several wells screened in the lower portion of Aquifer Zone 2B{sub 1} and Aquifer Unit 2A. Isoconcentration/isoactivity maps include in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units during the second half of 1993. Water-level maps indicate that the groundwater flow rates and directions at the HASB have remained relatively constant since the basins ceased to be active in 1988.

  18. Final technology report for D-Area oil seepage basin bioventing optimization test, environmental restoration support

    SciTech Connect

    Radway, J.C.; Lombard, K.H.; Hazen, T.C.

    1997-01-24

    One method proposed for the cleanup of the D-Area Oil Seepage Basin was in situ bioremediation (bioventing), involving the introduction of air and gaseous nutrients to stimulate contaminant degradation by naturally occurring microorganisms. To test the feasibility of this approach, a bioventing system was installed at the site for use in optimization testing by the Environmental Biotechnology Section of the Savannah River Technology Center. During the interim action, two horizontal wells for a bioventing remediation system were installed eight feet below average basin grade. Nine piezometers were also installed. In September of 1996, a generator, regenerative blower, gas cylinder station, and associated piping and nutrient injection equipment were installed at the site and testing was begun. After baseline characterization of microbial activity and contaminant degradation at the site was completed, four injection campaigns were carried out. These consisted of (1) air alone, (2) air plus triethylphosphate (TEP), (3) air plus nitrous oxide, and (4) air plus methane. This report describes results of these tests, together with conclusions and recommendations for further remediation of the site. Natural biodegradation rates are high. Oxygen, carbon dioxide, and methane levels in soil gas indicate substantial levels of baseline microbial activity. Oxygen is used by indigenous microbes for biodegradation of organics via respiration and hence is depleted in the soil gas and water from areas with high contamination. Carbon dioxide is elevated in contaminated areas. High concentrations of methane, which is produced by microbes via fermentation once the oxygen has been depleted, are found at the most contaminated areas of this site. Groundwater measurements also indicated that substantial levels of natural contaminant biodegradation occurred prior to air injection.

  19. A practical method of determining water current velocities and diffusion coefficients in coastal waters by remote sensing techniques

    NASA Technical Reports Server (NTRS)

    James, W. P.

    1971-01-01

    A simplified procedure is presented for determining water current velocities and diffusion coefficients. Dye drops which form dye patches in the receiving water are made from an aircraft. The changes in position and size of the patches are recorded from two flights over the area. The simplified data processing procedure requires only that the ground coordinates about the dye patches be determined at the time of each flight. With an automatic recording coordinatograph for measuring coordinates and a computer for processing the data, this technique provides a practical method of determining circulation patterns and mixing characteristics of large aquatic systems. This information is useful in assessing the environmental impact of waste water discharges and for industrial plant siting.

  20. GROUND WATER PROTECTION ISSUES WITH GEOTHERMAL HEAT PUMPS

    SciTech Connect

    ALLAN,M.L.; PHILIPPACOPOULOS,A.J.

    1999-10-01

    Closed loop vertical boreholes used with geothermal heat pumps are grouted to facilitate heat transfer and prevent ground water contamination. The grout must exhibit suitable thermal conductivity as well as adequate hydraulic sealing characteristics. Permeability and infiltration tests were performed to assess the ability of cementitious grout to control vertical seepage in boreholes. It was determined that a superplasticized cement-sand grout is a more effective borehole sealant than neat cement over a range of likely operational temperatures. The feasibility of using non-destructive methods to verify bonding in heat exchangers is reviewed.

  1. Using reactive artificial muscles to determine water exchange during reactions

    NASA Astrophysics Data System (ADS)

    Otero, T. F.; Martínez, J. G.; Zaifoglu, B.

    2013-10-01

    Artificial muscles based on films of conducting polymers translate film volume variations, driven by electrochemical reactions (Faradaic motors), into macroscopic movements with generation of mechanical energy. The reaction promotes exchange of counterions (anions here) and solvent molecules with the electrolyte. Attributing here both the film volume variation and the movement originated by these exchanges of ions and solvent, the described angles can be used to quantify the exchanged solvent. Different angles described by bending muscles consuming equal driving charges in electrolytes having the same cation and different anions were measured. The number of exchanged counterions is given by the consumed charge and the ion valence: this is a Faradaic reaction. The described angle fraction due to the exchanged anions is given by the number of anions and the crystallographic radius. Taking as reference the anion giving the shorter angle, whatever the consumed charge, the relative number of solvent molecules exchanged by the polymeric membrane during a reversible reaction was determined. Actuators and artificial muscles can be used as useful tools for, at least, an initial study of the solvent exchange during reactions in reactive gels.

  2. Determination of the delta(2H/1H)of Water: RSIL Lab Code 1574

    USGS Publications Warehouse

    Revesz, Kinga; Coplen, Tyler B.

    2008-01-01

    Reston Stable Isotope Laboratory (RSIL) lab code 1574 describes a method used to determine the relative hydrogen isotope-ratio delta(2H,1H), abbreviated hereafter as d2H of water. The d2H measurement of water also is a component of the National Water Quality Laboratory (NWQL) schedules 1142 and 1172. The water is collected unfiltered in a 60-mL glass bottle and capped with a Polyseal cap. In the laboratory, the water sample is equilibrated with gaseous hydrogen using a platinum catalyst (Horita, 1988; Horita and others, 1989; Coplen and others, 1991). The reaction for the exchange of one hydrogen atom is shown in equation 1.

  3. The effect of surficial disturbance on exchange between groundwater and surface water in near-shore margins

    USGS Publications Warehouse

    Rosenberry, Donald O.; Toran, Laura; Nyquist, Jonathan E.

    2010-01-01

    Low-permeability sediments situated at or near the sediment-water interface can influence seepage in nearshore margins, particularly where wave energy or currents are minimal. Seepage meters were used to quantify flow across the sediment-water interface at two lakes where flow was from surface water to groundwater. Disturbance of the sediment bed substantially increased seepage through the sandy sediments of both lakes. Seepage increased by factors of 2.6 to 7.7 following bed disturbance at seven of eight measurement locations at Mirror Lake, New Hampshire, where the sediment representing the greatest restriction to flow was situated at the sediment-water interface. Although the veneer of low-permeability sediment was very thin and easily disturbed, accumulation on the bed surface was aided by a physical setting that minimized wind-generated waves and current. At Lake Belle Taine, Minnesota, where pre-disturbance downward seepage was smaller than at Mirror Lake, but hydraulic gradients were very large, disturbance of a 20 to 30 cm thick medium sand layer resulted in increases in seepage of 2 to 3 orders of magnitude. Exceptionally large seepage rates, some exceeding 25,000 cm/d, were recorded following bed disturbance. Since it is common practice to walk on the bed while installing or making seepage measurements, disruption of natural seepage rates may be a common occurrence in nearshore seepage studies. Disturbance of the bed should be avoided or minimized when utilizing seepage meters in shallow, nearshore settings, particularly where waves or currents are infrequent or minimal.

  4. Connectivity between surface and deep waters determines prokaryotic diversity in the North Atlantic Deep Water

    PubMed Central

    Frank, Alexander H.; Garcia, Juan A. L.; Herndl, Gerhard J.

    2016-01-01

    Summary To decipher the influence of depth stratification and surface provincialism on the dark ocean prokaryotic community composition, we sampled the major deep‐water masses in the eastern North Atlantic covering three biogeographic provinces. Their diversity was evaluated using ordination and canonical analysis of 454 pyrotag sequences. Variance partitioning suggested that 16% of the variation in the bacterial community composition was based on depth stratification while 9% of the variation was due to geographic location. General linear mixed effect models showed that the community of the subsurface waters was connected to the dark ocean prokaryotic communities in different biogeographic provinces. Cluster analysis indicated that some prokaryotic taxa are specific to distinct regions in bathypelagic water masses. Taken together, our data suggest that the dark ocean prokaryotic community composition of the eastern North Atlantic is primed by the formation and the horizontal transport of water masses. PMID:26914787

  5. Determination of 3-amino-1,2,4-triazole (amitrole) in environmental waters by capillary electrophoresis.

    PubMed

    Chicharro, M; Zapardiel, A; Bermejo, E; Moreno, M

    2003-01-02

    3-Amino-1,2,4-triazole (amitrole) is a widely used pesticide, with many difficulties to be analyzed at the regulatory level in drinking water, because its high solubility in water. This paper describes a simple and fast method for the simultaneous determination of amitrole and atrazin-2-hydroxy, principal degradation product of s-triazines, by capillary zone electrophoresis. Separation and determination of these herbicides in water samples was performed in 0.02 mol l(-1) phosphate buffer at pH 3.2. The method allows determination of the amitrole and atrazin-2-hydroxy in water samples in concentration lower than 100 mug l(-1). The detection limits using a previous preconcentration step of amitrole in Alberche River (Comunidad Autónoma de Madrid, Spain) and drinking water spiked samples was of 4 mug l(-1).

  6. Determining Regional Sensitivity to Energy-Related Water Withdrawals in Minnesota

    NASA Astrophysics Data System (ADS)

    McCulloch, A.; Brauman, K. A.

    2015-12-01

    Minnesota has abundant freshwater resources, yet concerns about water-impacts of energy and mining development are increasing. Statewide, total annual water withdrawals have increased, and, in some watersheds, withdrawals make up a large fraction of available water. The energy and mining sectors play a critical role in determining water availability, as water is used to irrigate biofuel feedstock crops, cool thermoelectric plants, and process and transport fuels and iron ore. We evaluated the Minnesota Department of Natural Resources (DNR) Water and Reporting System (MPARS) dataset (1988-2014) to identify regions where energy and mining-related water withdrawals are high or where they are increasing. The energy and mining sectors account for over 65 percent of total water extractions in Minnesota, but this percentage is greater in some regions. In certain southern and northeastern Minnesota watersheds, these extractions account for 90 percent of total water demand. Sensitivity to these demands is not dependent on total water demand alone, and is also not uniform among watersheds. We identified and evaluated factors influencing sensitivity, including population, extraction type (surface water or groundwater), percentage of increased demand, and whether withdrawals are consumptive or not. We determined that southern Minnesota is particularly sensitive to increased water demands, because of growing biofuel and sand extraction industries (the products of which are used in hydraulic fracturing). In the last ten years, ethanol production in Minnesota has increased by 440 percent, and over fifteen refineries (each with a capacity over 1.1 billion gallons), have been built. These users primarily extract from surface water bodies within a few watersheds, compromising local supplies. As these energy-related industries continue to grow, so will the demand for freshwater resources. Determining regional sensitivity to increased demands will allow policy-makers to manage the

  7. Surface-water/ground-water relations in the Lemhi River Basin, east-central Idaho

    USGS Publications Warehouse

    Donato, Mary M.

    1998-01-01

    This report summarizes work carried out in cooperation with the Bureau of Reclamation to provide hydrologic information to help Federal, State, and local agencies meet the goals of the Lemhi River Model Watershed Project. The primary goal of the project is to maintain, enhance, and restore anadromous and resident fish habitat in the Lemhi River, while maintaining a balance between resource protection and established water uses. The main objectives of the study were to carry out seepage measurements to determine seasonal distributed gains and losses in the Lemhi River and to estimate annual ground-water underflow from the basin to the Salmon River. In 1997, seepage measurements were made during and after the irrigation season along a 60-mile reach of the Lemhi River between Leadore and Salmon. Except for one 4-mile reach that lost 1.3 cubic feet per second per mile, the river gained from ground water in early August when ground-water levels were high. Highest flows in the Lemhi River in early August were about 400 cubic feet per second. In October, when ground-water levels were low, river losses to ground water were about 1 to 16 cubic feet per second per mile. In October, highest flows in the Lemhi River were about 500 cubic feet per second, near the river's mouth. Annual ground-water underflow from the Lemhi River Basin to the Salmon River was estimated by using a simplified water budget and by using Darcy's equation. The water-budget method contained large uncertainties associated with estimating precipitation and evapotranspiration. Results of both methods indicate that the quantity of ground water leaving the basin as underflow is small, probably less than 2 percent of the basin's total annual water yield.

  8. Determination of characteristics and drinking water quality index in Mzuzu City, Northern Malawi

    NASA Astrophysics Data System (ADS)

    Wanda, Elijah M. M.; Gulula, Lewis C.; Phiri, Gift

    An assessment of characteristics and chemical water quality index (WQI) of water supplied by the Northern Region water Board (NRWB) in Mzuzu City was carried out in order to ascertain the quality of water for domestic purposes. The WQI offers a single number that expresses overall water quality for a water sample based on several water quality parameters. In this study raw water and 72 tap water samples were collected monthly between March and September, 2011 and analyzed for major ions, pH, total dissolved solids (TDSs), electrical conductivity (EC), turbidity, total hardness (TH), suspended solids (SSs) and alkalinity using standard methods. The quality and accuracy of the chemical data was assessed by checking electrical balances. The calculated electrical balance errors were found to be less than ±10%, which meant the results were reliable. Based on the Sawyer and McCarty TH classification, 100% of the samples were soft waters (TH < 150 mg/L). Nitrates, which registered medium or average WQ-rating of 69.77 and WQ-rating range of 52.06-86.94, were observed to have significantly affected the overall water quality index of the treated water since the rest of the parameters registered good-excellent WQ-ratings (average WQ-rating: 80.21-97.87). The pH, which is used to determine suitability of water for various purposes, ranged between 6.40 and 6.90 and registered a good water quality rating (WQ rating range: 72.73-87.02) for both raw and treated water. Raw water registered an overall medium water quality rating of 62.67%. Overall, 91.67% of the samples registered a good water quality rating (WQI range: 80.28-88.80%) and 8.33% registered a very good water quality rating (WQI = 90.07%). The results suggested substantial water treatment by the NRWB since the treated water is protected with some negligible degree of impairment that rarely departs from desirable levels of domestic water quality. It is recommended that the WQI should be adopted as a tool to monitor and

  9. The decisive role of free water in determining homogenous ice nucleation behavior of aqueous solutions.

    PubMed

    Wang, Qiang; Zhao, Lishan; Li, Chenxi; Cao, Zexian

    2016-05-26

    It is a challenging issue to quantitatively characterize how the solute and pressure affect the homogeneous ice nucleation in a supercooled solution. By measuring the glass transition behavior of solutions, a universal feature of water-content dependence of glass transition temperature is recognized, which can be used to quantify hydration water in solutions. The amount of free water can then be determined for water-rich solutions, whose mass fraction, Xf, is found to serve as a universal relevant parameter for characterizing the homogeneous ice nucleation temperature, the meting temperature of primary ice, and even the water activity of solutions of electrolytes and smaller organic molecules. Moreover, the effects of hydrated solute and pressure on ice nucleation is comparable, and the pressure, when properly scaled, can be incorporated into the universal parameter Xf. These results help establish the decisive role of free water in determining ice nucleation and other relevant properties of aqueous solutions.

  10. The decisive role of free water in determining homogenous ice nucleation behavior of aqueous solutions

    PubMed Central

    Wang, Qiang; Zhao, Lishan; Li, Chenxi; Cao, Zexian

    2016-01-01

    It is a challenging issue to quantitatively characterize how the solute and pressure affect the homogeneous ice nucleation in a supercooled solution. By measuring the glass transition behavior of solutions, a universal feature of water-content dependence of glass transition temperature is recognized, which can be used to quantify hydration water in solutions. The amount of free water can then be determined for water-rich solutions, whose mass fraction, Xf, is found to serve as a universal relevant parameter for characterizing the homogeneous ice nucleation temperature, the meting temperature of primary ice, and even the water activity of solutions of electrolytes and smaller organic molecules. Moreover, the effects of hydrated solute and pressure on ice nucleation is comparable, and the pressure, when properly scaled, can be incorporated into the universal parameter Xf. These results help establish the decisive role of free water in determining ice nucleation and other relevant properties of aqueous solutions. PMID:27225427

  11. Trace levels of metallic corrosion in water determined by emission spectrography

    NASA Technical Reports Server (NTRS)

    Snell, H. H.

    1966-01-01

    Emission spectrographic method determines trace amounts of inorganic impurities in potable water. The capability of this innovation should arouse considerable interest among plant biologists, chemists working in organic synthesis, and pathologists.

  12. EPA Method 245.1: Determination of Mercury in Water by Cold Vapor Atomic Absorption Spectrometry

    EPA Pesticide Factsheets

    SAM lists this method for preparation and analysis of aqueous liquid and drinking water samples. This method will determine mercuric chloride and methoxyethylmercuric acetate as total mercury using cold vapor atomic absorption spectrometry.

  13. WATER QUALITY AND OYSTER HEALTH (CRASSOSTREA VIRGINICA): AN INTEGRATED APPROACH TO DETERMINING HABITAT RESTORATION POTENTIAL

    EPA Science Inventory

    Volety, Aswani K., S. Gregory Tolley and James T. Winstead. 2001. Water Quality and Oyster Health (Crassostrea virginica): An Integrated Approach to Determining Habitat Restoration Potential (Abstract). Presented at the 5th International Conference on Shellfish Restoration, 18-21...

  14. THE BUBBLE STRIPPING METHOD FOR DETERMINING DISSOLVED HYDROGEN (H2) IN WELL WATER

    EPA Science Inventory

    The Bubble Strip Method was developed for determining concentrations of dissolved H2 in ground water (1). This information canaid in assessing the viability of employing the strategyof monitored natural attenuation (MNA) to restore sites contaminated with chlorinated hydrocarbon...

  15. Determination of Chlorine Dioxide and Chlorite in Water Supply Systems by Verified Methods

    NASA Astrophysics Data System (ADS)

    Tkáčová, Jana; Božíková, Jarmila

    2014-07-01

    This work is dedicated to the development and optimization of appropriate analytical methods for the determination of chlorine dioxide and chlorite in drinking water in order to obtain accurate and correct results in the quality control of drinking water. The work deals with the development and optimization of a method for the determination of chlorine dioxide using chlorophenol red. Furthermore, a new spectrophotometric method for the determination of chlorite via bromometry using methyl orange was developed, optimized and validated. An electrochemical method for the determination of chlorite by flow coulometry was also developed, optimized and validated.

  16. Determination of Aluminium and Physicochemical Parameters in the Palm Oil Estates Water Supply at Johor, Malaysia

    PubMed Central

    Siti Farizwana, M. R.; Mazrura, S.; Zurahanim Fasha, A.; Ahmad Rohi, G.

    2010-01-01

    The study was to determine the concentration of aluminium (Al) and study the physicochemical parameters (pH, total dissolved solids (TDS), turbidity, and residual chlorine) in drinking water supply in selected palm oil estates in Kota Tinggi, Johor. Water samples were collected from the estates with the private and the public water supplies. The sampling points were at the water source (S), the treatment plant outlet (TPO), and at the nearest houses (H1) and the furthest houses (H2) from the TPO. All estates with private water supply failed to meet the NSDWQ for Al with mean concentration of 0.99 ± 1.52 mg/L. However, Al concentrations in all public water supply estates were well within the limit except for one estate. The pH for all samples complied with the NSDWQ except from the private estates for the drinking water supply with an acidic pH (5.50 ± 0.90). The private water supply showed violated turbidity value in the drinking water samples (14.2 ± 24.1 NTU). Insufficient amount of chlorination was observed in the private water supply estates (0.09 ± 0.30 mg/L). Private water supplies with inefficient water treatment served unsatisfactory drinking water quality to the community which may lead to major health problems. PMID:21461348

  17. Determination of aluminium and physicochemical parameters in the palm oil estates water supply at Johor, Malaysia.

    PubMed

    Siti Farizwana, M R; Mazrura, S; Zurahanim Fasha, A; Ahmad Rohi, G

    2010-01-01

    The study was to determine the concentration of aluminium (Al) and study the physicochemical parameters (pH, total dissolved solids (TDS), turbidity, and residual chlorine) in drinking water supply in selected palm oil estates in Kota Tinggi, Johor. Water samples were collected from the estates with the private and the public water supplies. The sampling points were at the water source (S), the treatment plant outlet (TPO), and at the nearest houses (H1) and the furthest houses (H2) from the TPO. All estates with private water supply failed to meet the NSDWQ for Al with mean concentration of 0.99 ± 1.52 mg/L. However, Al concentrations in all public water supply estates were well within the limit except for one estate. The pH for all samples complied with the NSDWQ except from the private estates for the drinking water supply with an acidic pH (5.50 ± 0.90). The private water supply showed violated turbidity value in the drinking water samples (14.2 ± 24.1 NTU). Insufficient amount of chlorination was observed in the private water supply estates (0.09 ± 0.30 mg/L). Private water supplies with inefficient water treatment served unsatisfactory drinking water quality to the community which may lead to major health problems.

  18. Determining the in situ water content of the Geysers Graywacke of Northern California

    SciTech Connect

    Marsh, A.

    1994-12-01

    The water content, porosity and permeability measurements of the Northern California Geysers rocks are used to predict the lifetime of the geothermal resource, which provides 10% of Northern California`s electricity. The Geysers rock was drilled from defunct well SB-15-D, and some cores wee sealed in aluminum tubes to preserve the in situ water content. These cores were sent to the Lawrence Livermore Laboratory to measure the water content. Humidity measurements were taken of the air around a one and a half foot encased core, recovered from a depth of 918.9 feet. Over a seven day period, the humidity reached almost 100% indicating that the air around the core was saturated in water vapor. We believe the sealing method is effective, preserving the in-situ water content. To measure water content, I will use Archimede`s principle to determine the density of the core before and after drying in an oven. Ultrasonic measurements will be taken of the core upon removal from aluminum tube to determine the change of p-wave velocity with change in water content. Water in the pores increases the effective compressibility of the rock therefore increasing the p-velocity. The measured p-wave velocities can then be used in the field to determine in-situ water content. Three dimensional x-ray images will be used to determine the deviations from average density within individual cores. Since the density depends on water content as well as mineralogy, images can show the location of pore fluid and drilling mud. Archimede`s principle, humidity detection, ultrasonics and x-ray scanning are viable methods to measure the in-situ water content and pore water distribution in the graywacke.

  19. TECHNIQUES AND METHODS FOR THE DETERMINATION OF HALOACETIC ACIDS IN POTABLE WATER

    EPA Science Inventory

    Haloethanoic (haloacetic) acids (HAAs) are formed as disinfection byproducts (DBPs) during the chlorination of natural water to make it fit for consumption. Sundry analytical techniques have been applied in order to determine the concentrations of the HAAs in potable water suppli...

  20. Methods for the Determination of Bacteriological Contaminants in Drinking Water. Training Manual.

    ERIC Educational Resources Information Center

    Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

    Material on the membrane filter methods and the most probable number method for determining bacteriological contaminants listed in the interim primary drinking water regulations is presented. This course is for bacteriologists and technicians with little or no experience in bacteriological procedures required to monitor drinking water, though…

  1. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

    ERIC Educational Resources Information Center

    Riehl, Matthew

    2012-01-01

    A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

  2. Determination of the amount of Cs-137 in the sea water obtained from the Dardanelles

    NASA Astrophysics Data System (ADS)

    Ataseven, D.; Şen, S.

    2017-02-01

    After the Chernobyl accident, high concentrations of Cs-137 radioisotope reached the Black Sea through dry and wet fallout. Therefore, a number of studies were performed to determine the current activity of Cs-137 near this region in the sea water and in marine organisms. Cs-137 activity was determined in the Dardanelles sea water taken from three separate locations and two different depths for each location. The old data base obtained in our previous studies was updated.

  3. Data on ground-water levels and ground-water/surface-water relations in the Great Miami River and Little Miami River valleys, southwestern Ohio

    USGS Publications Warehouse

    Yost, William P.

    1995-01-01

    Hydrogeologic data were collected in September, October, and November 1993 to define the ground-water levels and the ground-water/surface-water relations in the vicinity of Dayton, Ohio. In this report, water levels are listed for 678 wells completed in sand and gravel. Data from 101 streamflow measurements made at selected sites along the Great Miami, Stillwater, Mad, and Little Miami Rivers and their tributaries during 2-day gain-loss study also are listed. Surface-water altitudes were determined at 11 stream-gaging stations and 39 other streamflow measurement sites. Discharge data for measurements made at 30 storm-sewer outfalls are given. Streamflow and discharge data obtained during the study were used to calculate the gain or loss of streamflow along 16 selected reaches of the Great Miami, Stillwater, Mad, and Little Miami Rivers. Streambed-conductivity data obtained by use of seepage meters at nine different sites also are given.

  4. [Determination of rubidium and cesium in chloride type oilfield water by flame atomic absorption spectrometry].

    PubMed

    Ye, Xiu-Shen; Zhang, Shan-Ying; Li, Hai-Jun; Li, Wu; Wu, Zhi-Jian

    2009-03-01

    Flame atomic absorption spectrometry (FAAS) was applied to the determination of rubidium and cesium in chloride type oilfield water by considering the interferences of the coexistent K+, Na+, Ca2+, and Mg2+ ions, Standard curve method and standard addition method were compared in the determination of rubidium and cesium in the simulated oilfield water and the real oilfield water from the Nanyishan region in Qaidam Basin. Although rubidium and cesium have similar physical-chemical properties, they present different characters during their analyses using the FAAS technique. When the standard addition method was used for the determination of rubidium and cesium in the simulated oilfield water, the results of rubidium were very poor, whereas the results of cesium were satisfactory. When the standard curve method was used for the determination of rubidium and cesium in the simulated oilfield water, the results of both rubidium and cesium were satisfactory within the linear ranges of the standard curves. For the real oilfield water, standard addition method is also only applicable for the determination of cesium with a recovery ranging from 90% to 110%. While standard curve method is applicable for the determination of both rubidium and cesium with a recovery ranging from 90% to 110%.

  5. Multisample conversion of water to hydrogen by zinc for stable isotope determination

    USGS Publications Warehouse

    Kendall, C.; Coplen, T.B.

    1985-01-01

    Two techniques for the conversion of water to hydrogen for stable isotope ratio determination have been developed that are especially suited for automated multisample analysis. Both procedures involve reaction of zinc shot with a water sample at 450 ??C. in one method designed for water samples in bottles, the water is put in capillaries and is reduced by zinc in reaction vessels; overall savings in sample preparation labor of 75% have been realized over the standard uranium reduction technique. The second technique is for waters evolved under vacuum and is a sealed-tube method employing 9 mm o.d. quartz tubing. Problems inherent with zinc reduction include surface inhomogeneity of the zinc and exchange of hydrogen both with the zinc and with the glass walls of the vessels. For best results, water/zinc and water/glass surface area ratios of vessels should be kept as large as possible.

  6. Trace level determination of u, zn, cd, pb and cu in drinking water samples.

    PubMed

    Kumar, Mukesh; Singh, Surinder; Mahajan, Rakesh Kumar

    2006-01-01

    The concentration of uranium has been assessed in drinking water samples collected from different locations in Bathinda district, Punjab, India. The water samples are taken from hand pumps and tube wells. Uranium is determined using fission track technique. Uranium concentration in the water samples varies from 2.23+/- 0.05 to 87.05+/- 0.29 microg/L. These values are compared with safe limit values recommended for drinking water. The uranium concentration in almost all drinking water samples is found to be more than the safe limit. Analysis of some heavy metals viz. Zn, Cd, Pb and Cu in water is made. The concentration of sodium, potassium, calcium, magnesium, chlorine and total hardness along with the pH value and conductivity of the water samples are measured. Some of the samples show stunningly high values of these parameters.

  7. SEEPAGE FLOW DYNAMICS IN A NEGATIVE PRESSURE DIFFERENCE IRRIGATION SYSTEM

    NASA Astrophysics Data System (ADS)

    Moniruzzaman, S. M.; Fukuhara, Teruyuki; Ito, Masaki; Ishii, Yoshihiro

    This study proposes a theoretical model to predict soil wetting pattern and water balance in a negative pressure difference irrigation (NPDI) system and describes laboratory experimental results from which this model was derived. The experiments were conducted by using a porous pipe, a water reservoir and a soil column filled with Kawanishi sand. The temporal variations in volumetric water content profile, supplied water, soil water storage and evaporation were calculated by the proposed model. The calculated results were in good agreement with the experimental results. The margin of error of the water balance was in the range of 3 to 7 %. It is concluded that the proposed model is valid for an optimal design of the NPDI system.

  8. Multi-pumping flow system for the determination of boron in eye drops, drinking water and ocean water.

    PubMed

    González, Pablo; Sixto, Alexandra; Knochen, Moisés

    2017-05-01

    A novel automated method for the determination of boron based on the use of pulsed flows was developed and applied to the determination of this element in samples of tap water, ocean water and eye drops. The method was implemented by means of a multi-pumping system consisting of three solenoid micropumps and a photometric detector and exploits the reaction of azomethine-H in the presence of boron. The system runs under control of an open-source microcontroller. The main operational parameters were optimized. Given the particular kinetics of the reaction, a stopped-flow period (1 or 5min) was included to allow for color development. The method presents linearity in the range 0.35-3.0mgL(-1), good precision (sr<3%), and detection and quantification limits of 0.10 and 0.35mgL(-1) respectively. Samples of tap water or eye drops could be successfully analyzed employing a 1-minute stop time, providing a maximum sampling frequency of 32 samples h(-1). In order to overcome matrix effect caused by the high saline concentration, ocean water samples required stop times of 5min, providing a sampling frequency of 10 samples h(-1). Recoveries of 102% (eye drops), 94% (drinking water) and 93% (ocean water) were obtained. The method was considered accurate and fit for the purpose.

  9. The use of stable isotopes in quantitative determinations of exogenous water and added ethanol in wines

    NASA Astrophysics Data System (ADS)

    Magdas, D. A.; Moldovan, Z.; Cristea, G.

    2012-02-01

    The application of oxygen isotope ratios analysis to wine water according to EU regulation no. 822/97 to determine wine's origin and also, the possible water addition to wines, gained great importance in wines authenticity control. In the natural cycle of water isotopic fractionation, during water evaporation process, the water vapors are depleted in heavy isotopes. On the other hand inside the plants take place an isotope enrichment of heavy stable isotopes of water compared with meteoric water due to photosynthesis and plants transpiration. This process makes possible the detection of exogenous water from wines 18O/16O ratios. Carbon isotopic ratios were used to estimate the supplementary addition of ethanol obtained from C4 plants (sugar cane or corn). This work presents the way in which the isotopic fingerprints (δ13C and δ18O) were used to determine the content of exogenous water from wines and the added supplementary ethanol coming from C4 plants. By using this method, the calculated values obtained for the degree of wine adulteration were in a good agreement with the real exogenous percent of water and ethanol from investigated samples.

  10. Artificial neural networks for defining the water quality determinants of groundwater abstraction in coastal aquifer

    NASA Astrophysics Data System (ADS)

    Lallahem, S.; Hani, A.

    2017-02-01

    Water sustainability in the lower Seybouse River basin, eastern Algeria, must take into account the importance of water quantity and quality integration. So, there is a need for a better knowledge and understanding of the water quality determinants of groundwater abstraction to meet the municipal and agricultural uses. In this paper, the artificial neural network (ANN) models were used to model and predict the relationship between groundwater abstraction and water quality determinants in the lower Seybouse River basin. The study area chosen is the lower Seybouse River basin and real data were collected from forty five wells for reference year 2006. Results indicate that the feed-forward multilayer perceptron models with back-propagation are useful tools to define and prioritize the important water quality parameters of groundwater abstraction and use. The model evaluation shows that the correlation coefficients are more than 95% for training, verification and testing data. The model aims to link the water quantity and quality with the objective to strengthen the Integrated Water Resources Management approach. It assists water planners and managers to better assess the water quality parameters and progress towards the provision of appropriate quantities of water of suitable quality.

  11. Methane-derived carbonates as archives of past seepage activity along the Norwegian margin

    NASA Astrophysics Data System (ADS)

    Crémière, Antoine; Lepland, Aivo; Sahy, Diana; Noble, Stephen R.; Condon, Daniel J.; Chand, Shyam; Stoddart, Daniel; Halvard Pedersen, Jon; Sauer, Simone; Brunstad, Harald; Birger Pedersen, Rolf; Thornes, Terje

    2014-05-01

    Assessment of timing and flux rates of past methane discharges is in part hindered by the lack of robust age constraints. Authigenic carbonate crusts forming in shallow sediments due to the oxidation of methane are recorders of seepage that can be dated by using U-daughter decay affording the unique opportunity to constrain the absolute timing of methane release events. Methane-derived carbonate crusts exhibiting characteristic 13C-depleted isotopic signatures were collected from several seepage sites on the Norwegian continental shelf, including sites in the North Sea, the Norwegian Sea and the Barents Sea. The U-Th dating results constrain the main episode of carbonate crust formation in the Barents and Norwegian seas during the time interval between 14 and 7 ka. Such ages suggest that the methane seepage along the northern Norwegian margin was most active after the collapse of the Scandinavian ice sheet and deglaciation of the area that took place at about 15 ka. The methane flux for the carbonate crust formation was likely provided by the dissociation of methane hydrates that extensively formed in underlying sediments during the last glacial period, but became unstable due to depressuring effects of retreating ice sheet. The precipitation of studied North Sea carbonate crusts occurred more recently, from 6 to 1 ka, suggesting that their formation is unrelated to the glacial history of the area and gas hydrate stability. Carbonate crust formation in the North Sea is likely related to the methane seepage from the hydrocarbon reservoir and the dating results allow an assessment of the seepage history within individual conduits.

  12. Determination of traces of silver in waters by anion exchange and atomic absorption spectrophotometry

    USGS Publications Warehouse

    Chao, T.T.; Fishman, M. J.; Ball, J.W.

    1969-01-01

    A method has been developed for the accurate determination of 0.1-1 ??g of silver per liter of water. The method permits stabilization of silver in water without loss to container walls. Optimum conditions have been established for the complete recovery of silver from water with an anion-exchange column, for quantitative elution of silver from the resin, and for measurement of silver by atomic absorption spectrophotometry after chelation with ammonium pyrrolidine dithiocarbamate and extraction of the chelate with MIBK. Silver in the 1-10 ??g 1 range can be determined by extraction without pre-concentration on an ion-exchange resin. ?? 1969.

  13. Determination of pyrazon residues in water by reversed phase high performance liquid chromatography.

    PubMed

    Ahmad, I

    1982-01-01

    A simple analytical method is described for the quantitative determination of pyrazon residues in water. It involves high performance liquid chromatography with ultraviolet detection at 270 nm. The procedure is used to determine 2 ppb to 1 ppm levels of pyrazon in water. The traditional liquid-liquid extraction method has been replaced by an adsorption-trapping method for the extraction of pyrazon. Average recovery of pyrazon from the laboratory spiked samples was 98.1%. The method can be used for water samples with concentrations as low as 2 ppb.

  14. Filtration of water-sediment samples for the determination of organic compounds

    USGS Publications Warehouse

    Sandstrom, Mark W.

    1995-01-01

    This report describes the equipment and procedures used for on-site filtration of surface-water and ground-water samples for determination of organic compounds. Glass-fiber filters and a positive displacement pumping system are suitable for processing most samples for organic analyses. An optional system that uses disposable in-line membrane filters is suitable for a specific gas chromatography/mass spectrometry, selected-ion monitoring analytical method for determination of organonitrogen herbicides. General procedures to minimize contamination of the samples include preparing a clean workspace at the site, selecting appropriate sample-collection materials, and cleaning of the equipment with detergent, tap water, and methanol.

  15. Crop kites: Determining crop-water production functions using crop coefficients and sensitivity indices

    NASA Astrophysics Data System (ADS)

    Smilovic, Mikhail; Gleeson, Tom; Adamowski, Jan

    2016-11-01

    The crop-water production function quantitatively evaluates the relationship between seasonal water use and crop yield and is used to evaluate optimal irrigation depth and assess the potential of deficit and supplemental irrigation. A simple and easily applicable methodology to develop crop- and region-specific crop-water production functions using crop coefficients and sensitivity-indices is presented. Previous efforts to describe the crop-water production function have not accounted for the effects of the temporal distribution of water use and trivialize the associated variability in yields by assuming an optimized or arbitrary temporal distribution. The temporal distribution of water use throughout the growing season can significantly influence crop yield, and the ability of farmers to manage both the timing and amount of irrigation water may result in higher yields. We propose crop kites, a tool that explicitly acknowledges crop yield as a function of the temporal distribution of water use to both evaluate the complete space of water use and crop yield relationships, and extract from this space specific crop-water production functions. An example for winter wheat is presented using previously validated crop-specific sensitivity indices. Crop-water production functions are extracted from the crop kite related to specific irrigation schedules and temporal distributions of water use. Crop-water production functions associated with maximizing agricultural production agree with previous efforts characterizing the shape as a diminishing curvilinear function. Crop kites provide the tools for water managers and policy makers to evaluate crop- and region-specific agricultural production as it relates to water management and the associated economics, and to <