Structural and Functional Characteristics of Natural and Constructed Channels Draining a Reclaimed Mountaintop Removal and Valley Fill Coal Mine

EPA Science Inventory

Mountaintop removal and valley fill (MTR/VF) coal mining has altered the landscape of the Central Appalachian region in the USA. Among the changes are large-scale topographic recontouring, burial of headwater streams, and degradation of downstream water quality. The goals of our ...

Stream water quality in the coal region of West Virginia and Maryland

Treesearch

Kenneth L. Dyer

1982-01-01

This report is a compilation of water quality data for 118 small streams sampled in 27 counties of West Virginia and nine streams in two counties of western Maryland. Forty-eight of these streams drain unmined watersheds; 79 drain areas where coal has been surface mined. Most of these streams were sampled at approximate monthly intervals. The water quality data from...

Design and performance of limestone drains to increase pH and remove metals from acidic mine drainage, Chapter 2

USGS Publications Warehouse

Cravotta,, Charles A.; Watzlaf, George R.

2002-01-01

Data on the construction characteristics and the composition of influent and effluent at 13 underground, limestone-filled drains in Pennsylvania and Maryland are reported to evaluate the design and performance of limestone drains for the attenuation of acidity and dissolved metals in acidic mine drainage. On the basis of the initial mass of limestone, dimensions of the drains, and average flow rates, the initial porosity and average detention time for each drain were computed. Calculated porosity ranged from 0.12 to 0.50 with corresponding detention times at average flow from 1.3 to 33 h. The effectiveness of treatment was dependent on influent chemistry, detention time, and limestone purity. At two sites where influent contained elevated dissolved Al (>5 mg/liter), drain performance declined rapidly; elsewhere the drains consistently produced near-neutral effluent, even when influent contained small concentrations of dissolved Fe^+ (<5 mg/liter). Rates of limestone dissolution computed on the basis of average long-term Ca ion flux normalized by initial mass and purity of limestone at each of the drains ranged from 0.008 to 0.079 year-1. Data for alkalinity concentration and flux during 11-day closed-container tests using an initial mass of 4kg crushed limestone and a solution volume of 2.3 liter yielded dissolution rate constants that were comparable to these long-term field rates. An analytical method is proposed using closed-container test data to evaluate long-term performance (longevity) or to estimate the mass of limestone needed for a limestone treatment. This method condisers flow rate, influent alkalinity, steady-state alkalinity of effluent, and desired effluent alkalinity or detention time at a future time(s) and aplies first-order rate laws for limestone dissolution (continuous) and production of alkalinity (bounded).

Structural and functional characteristics of natural and constructed channels draining a reclaimed mountaintop removal and valley fill coal mine

EPA Science Inventory

Mountaintop removal and valley fill (MTR/VF) coal mining has altered the landscape of the Central Appalachian region in the United States. The goals of this study were to 1) compare the structure and function of natural and constructed stream channels in forested and MTR/VF catch...

Sources of mercury to San Francisco Bay surface sediment as revealed by mercury stable isotopes

USGS Publications Warehouse

Gehrke, Gretchen E.; Blum, Joel D.; Marvin-DePasquale, Mark

2011-01-01

Mercury (Hg) concentrations and isotopic compositions were examined in shallow-water surface sediment (0–2 cm) from San Francisco (SF) Bay to determine the extent to which historic Hg mining contributes to current Hg contamination in SF Bay, and to assess the use of Hg isotopes to trace sources of contamination in estuaries. Inter-tidal and wetland sediment had total Hg (HgT) concentrations ranging from 161 to 1529 ng/g with no simple gradients of spatial variation. In contrast, inter-tidal and wetland sediment displayed a geographic gradient of δ202Hg values, ranging from -0.30% in the southern-most part of SF Bay (draining the New Almaden Hg District) to -0.99% in the northern-most part of SF Bay near the Sacramento–San Joaquin River Delta. Similar to SF Bay inter-tidal sediment, surface sediment from the Alviso Slough channel draining into South SF Bay had a δ202Hg value of -0.29%, while surface sediment from the Cosumnes River and Sacramento–San Joaquin River Delta draining into north SF Bay had lower average δ202Hg values of -0.90% and -0.75%, respectively. This isotopic trend suggests that Hg-contaminated sediment from the New Almaden Hg District mixes with Hg-contaminated sediment from a low δ202Hg source north of SF Bay. Tailings and thermally decomposed ore (calcine) from the New Idria Hg mine in the California Coast Range had average δ202Hg values of -0.37 and +0.03%, respectively, showing that Hg calcination fractionates Hg isotopes resulting in Hg contamination from Hg(II) mine waste products with higher δ202Hg values than metallic Hg(0) produced from Hg mines. Thus, there is evidence for at least two distinct isotopic signals for Hg contamination in SF Bay: Hg associated with calcine waste materials at Hg mines in the Coast Range, such as New Almaden and New Idria; and Hg(0) produced from these mines and used in placer gold mines and/or in other industrial processes in the Sierra Nevada region and SF Bay area.

Selected Metals in Sediments and Streams in the Oklahoma Part of the Tri-State Mining District, 2000-2006

USGS Publications Warehouse

Andrews, William J.; Becker, Mark F.; Mashburn, Shana L.; Smith, S. Jerrod

2009-01-01

The abandoned Tri-State mining district includes 1,188 square miles in northeastern Oklahoma, southeastern Kansas, and southwestern Missouri. The most productive part of the Tri-State mining district was the 40-square mile part in Oklahoma, commonly referred to as 'the Picher mining district' in north-central Ottawa County, Oklahoma. The Oklahoma part of the Tri-State mining district was a primary producing area of lead and zinc in the United States during the first half of the 20th century. Sulfide minerals of cadmium, iron, lead, and zinc that remained in flooded underground mine workings and in mine tailings on the land surface oxidized and dissolved with time, forming a variety of oxide, hydroxide, and hydroxycarbonate metallic minerals on the land surface and in streams that drain the district. Metals in water and sediments in streams draining the mining district can potentially impair the habitat and health of many forms of aquatic and terrestrial life. Lakebed, streambed and floodplain sediments and/or stream water were sampled at 30 sites in the Oklahoma part of the Tri-State mining district by the U.S. Geological Survey and the Oklahoma Department of Environmental Quality from 2000 to 2006 in cooperation with the U.S. Environmental Protection Agency, and the Quapaw and Seneca-Cayuga Tribes of Oklahoma. Aluminum and iron concentrations of several thousand milligrams per kilogram were measured in sediments collected from the upstream end of Grand Lake O' the Cherokees. Manganese and zinc concentrations in those sediments were several hundred milligrams per kilogram. Lead and cadmium concentrations in those sediments were about 10 percent and 0.1 percent of zinc concentrations, respectively. Sediment cores collected in a transect across the floodplain of Tar Creek near Miami, Oklahoma, in 2004 had similar or greater concentrations of those metals than sediment cores collected at the upstream end of Grand Lake O' the Cherokees. The greatest concentrations of cadmium, iron, lead, and zinc were detected in sediments beneath an intermittent tributary to Tar Creek, a slough which drains mined areas near Commerce, Oklahoma. In surface water, aluminum and iron concentrations were greatest in the Neosho River, perhaps a result of runoff from areas underlain by shales. The greatest aqueous concentrations of cadmium, lead, manganese, and zinc were measured in water from Tar Creek, the primary small stream draining the Picher mining district with the largest proportion of mined area. Water from the Spring River had greater zinc concentrations than water from the Neosho River, perhaps as a result of a greater proportion of mined area in the Spring River Basin. Dissolved metals concentrations were generally much less than total metals concentrations, except for manganese and zinc at sites on Tar Creek, where seepage of ground water from the mine workings, saturated mine tailings, and/or metalliferous streambed sediments may be sources of these dissolved metals. Iron and lead concentrations generally decreased with increasing streamflow in upstream reaches of Tar Creek, indicating dilution of metals-rich ground water by runoff. Farther downstream in Tar Creek, and in the Neosho and Spring Rivers, metals concentrations tended to increase with increasing streamflow, indicating that most metals in these parts of these streams were associated with runoff and re-suspension of metals precipitated as oxide, hydroxide, and hydroxycarbonate minerals on land surface and streambeds. Estimated total aluminum, cadmium, iron, manganese, and zinc loads generally were greatest in water from the Neosho and Spring Rivers, primarily because of comparatively large streamflows in those rivers. Slight increases in metal loads in the downstream directions on those rivers indicated contributions of metals from inflows of small tributaries such as Tar Creek and from runoff.

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

USGS Publications Warehouse

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

2007-01-01

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

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

USGS Publications Warehouse

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

2007-01-01

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

Ecological effects of lead mining on Ozark streams: In-situ toxicity to woodland crayfish (Orconectes hylas)

USGS Publications Warehouse

Allert, A.L.; Fairchild, J.F.; DiStefano, R.J.; Schmitt, C.J.; Brumbaugh, W.G.; Besser, J.M.

2009-01-01

The Viburnum Trend mining district in southeast Missouri, USA is one of the largest producers of lead-zinc ore in the world. Previous stream surveys found evidence of increased metal exposure and reduced population densities of crayfish immediately downstream of mining sites. We conducted an in-situ 28-d exposure to assess toxicity of mining-derived metals to the woodland crayfish (Orconectes hylas). Crayfish survival and biomass were significantly lower at mining sites than at reference and downstream sites. Metal concentrations in water, detritus, macroinvertebrates, fish, and crayfish were significantly higher at mining sites, and were negatively correlated with caged crayfish survival. These results support previous field and laboratory studies that showed mining-derived metals negatively affect O. hylas populations in streams draining the Viburnum Trend, and that in-situ toxicity testing was a valuable tool for assessing the impacts of mining on crayfish populations.

Drainage Adits in Upper Silesia - Industrial Technology Heritage and Important Elements of the Hydrotechnical Infrastructure

NASA Astrophysics Data System (ADS)

Duży, Stanisław; Dyduch, Grzegorz; Preidl, Wojciech; Stacha, Grzegorz

2017-12-01

Adits played an important role in the hydrotechnical infrastructure for centuries. Initially, they were used mainly to drain wetland and supply water to the population. There were also inherent in the conduct of mining activities. They were used as exploratory, development and supply headings. Their usual function was to drain, ventilate and transport, and after the cessation of mining they became important elements of the hydrotechnical infrastructure in the transformed mining areas. The article presents issues related to the revitalization of the Main Key Hereditary Adit and Friedrich Adit as essential for the areas in which they are located. Both are hydraulic structures with the possibility of adaptation for tourism purposes. The need to consider some technical activities to be undertaken in this type of objects was pointed out, not only including aspects related to their proper protection so that they can continue to safely perform their function, but also to the preservation of their historical values. Due to their age and the method of drilling used in them, those headings are often included in the list of monuments and protected by law.

Geology and ore deposits of the Breckenridge district, Colorado

USGS Publications Warehouse

Ransome, Frederick Leslie

1911-01-01

The Breckenridge district is situated in Summit County, Colo., 60 miles. west-southwest of Denver, near the crest of the Continental Divide, and is drained by Blue River, a tributary of the Grand. Placer mining began here in 1860, but it was not until about 1879 that attention was turned to lode mining. During the last five years gold dredging, after many failures, has become established as an important industry.

The Historical Use Of Mine-Drainage And Pyrite-Oxidation Waters In Central And Eastern England, United Kingdom

NASA Astrophysics Data System (ADS)

Banks, David; Younger, Paul L.; Dumpleton, Steve

1996-04-01

Waters draining from abandoned coal or metals mines are often regarded as an environmental threat. Historical examples from the lead and coal mining industries of central and northeastern England illustrate that mine waters can also be regarded as an important resource in terms of 1) baseflow for effluent dilution; 2) drinking or industrial waters; 3) flocculating agents for sewage or water treatment; 4) spa waters; 5) sources of industrial minerals, including alkali metals and barium; and 6) a source of iron oxides or sulphates for tanning or pigmentation purposes. An appreciation of the potential economic value of mine waters and their contents is essential for the design of cost-effective treatment options.

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

USGS Publications Warehouse

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

1985-01-01

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

Mercury and methylmercury concentrations and loads in the Cache Creek watershed, California

USGS Publications Warehouse

Domagalski, Joseph L.; Alpers, Charles N.; Slotton, D.G.; Suchanek, T.H.; Ayers, S.M.

2004-01-01

Concentrations and loads of total mercury and methylmercury were measured in streams draining abandoned mercury mines and in the proximity of geothermal discharge in the Cache Creek watershed of California during a 17-month period from January 2000 through May 2001. Rainfall and runoff were lower than long-term averages during the study period. The greatest loading of mercury and methylmercury from upstream sources to downstream receiving waters, such as San Francisco Bay, generally occurred during or after winter rainfall events. During the study period, loads of mercury and methylmercury from geothermal sources tended to be greater than those from abandoned mining areas, a pattern attributable to the lack of large precipitation events capable of mobilizing significant amounts of either mercury-laden sediment or dissolved mercury and methylmercury from mine waste. Streambed sediments of Cache Creek are a significant source of mercury and methylmercury to downstream receiving bodies of water. Much of the mercury in these sediments is the result of deposition over the last 100-150 years by either storm-water runoff, from abandoned mines, or continuous discharges from geothermal areas. Several geochemical constituents were useful as natural tracers for mining and geothermal areas, including the aqueous concentrations of boron, chloride, lithium and sulfate, and the stable isotopes of hydrogen and oxygen in water. Stable isotopes of water in areas draining geothermal discharges showed a distinct trend toward enrichment of 18O compared with meteoric waters, whereas much of the runoff from abandoned mines indicated a stable isotopic pattern more consistent with local meteoric water. ?? 2004 Elsevier B.V. All rights reserved.

An evaluation of problems arising from acid mine drainage in the vicinity of Shasta Lake, Shasta County, California

USGS Publications Warehouse

Fuller, Richard H.; Shay, J.M.; Ferreira, R.F.; Hoffman, R.J.

1978-01-01

Streams draining the mined areas of massive sulfide ore deposits in the Shasta Mining Districts of northern California are generally acidic and contain large concentrations of dissolved metals, including iron, copper, and zinc. The streams, including Flat, Little Backbone, Spring, West Squaw, Horse, and Zinc Creeks, discharge into Shasta Reservoir and the Sacramento River and have caused numerous fish kills. The sources of pollution are discharge from underground mines, streams that flow into open pits, and streams that flow through pyritic mine dumps where the oxidation of pyrite and other sulfide minerals results in the production of acid and the mobilization of metals. Suggested methods of treatment include the use of air and hydraulic seals in the mines, lime neutralization of mine effluent, channeling of runoff and mine effluent away from mine and tailing areas, and the grading and sealing of mine dumps. A comprehensive preabatement and postabatement program is recommended to evaluate the effects of any treatment method used. (Woodard-USGS)

Dewatering of the Jenkins open pit uranium mine

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

Straskraba, V.; Kissinger, L.E.

Mining of low grade uranium sandstones in the Jenkins open pit mine in the Shirley Basin, Wyoming was troubled by slope failures and wet conditions in the pit. Since the mine was expanding toward a river, the possibility of drainage from this river into the mine raised serious concern during the mine planning. A baseline hydrogeologic study was performed and dewatering measures were designed with the help of a numerical mathematical model. A combination of dewatering wells installed from the surface around the perimeter of the pit and horizontal drains in areas of high slope failure potential substantially improved themore » mining conditions and slope stability. This procedure consequently led to the successful ore recovery from the highly saturated sandstone strata. The development of drawdown during the dewatering of two separated aquifers in the overburden was close to that predicted by the model.« less

Appraisement of environment remote sensing method in mining area

NASA Astrophysics Data System (ADS)

Yang, Fengjie; Zhen, Han; Jiang, Tao; Lei, Liqing; Gong, Cailan

1998-08-01

Coal mining is attached great importance by society as a key profession of environmental pollution. The monitor and protection of coal-mine environment is a developing profession in China. The sulfur dioxide, carbon dioxide, carbon monoxide and other waste gases, which are put out by the spontaneous combustion or weathering of gangue are an important pollution resource of atmosphere. The stack of gangue held down many farmlands. Smoke, coal dust and powder coal ash pollute the environment of mining area and surroundings though the affection of monsoon. The pH value of water which coal mine drained off is low, and the drinking, farming and animal husbandry water where it flowed are affected. The surface subsidence which mining caused is a typical destruction of ground environment. The people pay attention to remote sensing as a method of rapidly, cheaply regional environment investigation. The paper tires making an appraisement of mining area environment monitor by many kind methods of remote sensing from the characteristic of mining area environment.

Hydrologic investigation and remediation of a post-remining acidic seep

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

Aljoe, W.W.; Linberg, N.A.

1996-12-31

Surface remining of coal pillars in abandoned underground workings in the Pittsburgh seam in southwestern Pennsylvania has often resulted in post-remining discharges whose water quality is the same or better than the pre-existing discharges. However, at one such operation in Washington County, PA, an increase in contaminant loading occurred at an outcrop seep after remining. This problem was believed to be at least partly related to a small unstrapped area of the old deep mine workings immediately upgradient from the seep. A hydrologic investigation that included a chemical tracer test, slug tests in the remined spoil, and water quality monitoringmore » indicated that the mine pool in the old workings discharged through the seep. However, the water in the mine pool and much of the remined spoil was consistently alkaline; this suggested that the acidic water may have originated in other areas of the spoil and old workings, and passed rapidly to the seep through a highly transmissive portion of the spoil. Acting on this assumption, the mine operator successfully implemented a remediation scheme in which the spoil was excavated to intercept the acidic spoil water. The excavation was then re-emplaced with an anoxic limestone drain at its base. The drain now serves both to add alkalinity to the water and to divert the seep to an area where metals can be removed easily via precipitation in wetlands.« less

Hydrogeochemical effects of a bulkhead in the Dinero mine tunnel, Sugar Loaf mining district, near Leadville, Colorado

USGS Publications Warehouse

Walton-Day, Katherine; Mills, Taylor J.

2015-01-01

The Dinero mine drainage tunnel is an abandoned, draining mine adit near Leadville, Colorado, that has an adverse effect on downstream water quality and aquatic life. In 2009, a bulkhead was constructed (creating a mine pool and increasing water-table elevations behind the tunnel) to limit drainage from the tunnel and improve downstream water quality. The goal of this study was to document changes to hydrology and water quality resulting from bulkhead emplacement, and to understand post-bulkhead changes in source water and geochemical processes that control mine-tunnel discharge and water quality. Comparison of pre-and post-bulkhead hydrology and water quality indicated that tunnel discharge and zinc and manganese loads decreased by up to 97 percent at the portal of Dinero tunnel and at two downstream sites (LF-537 and LF-580). However, some water-quality problems persisted at LF-537 and LF-580 during high-flow events and years, indicating the effects of the remaining mine waste in the area. In contrast, post-bulkhead water quality degraded at three upstream stream sites and a draining mine tunnel (Nelson tunnel). Water-quality degradation in the streams likely occurred from increased contributions of mine-pool groundwater to the streams. In contrast, water-quality degradation in the Nelson tunnel was likely from flow of mine-pool water along a vein that connects the Nelson tunnel to mine workings behind the Dinero tunnel bulkhead. Principal components analysis, mixing analysis, and inverse geochemical modeling using PHREEQC indicated that mixing and geochemical reactions (carbonate dissolution during acid weathering, precipitation of goethite and birnessite, and sorption of zinc) between three end-member water types generally explain the pre-and post-bulkhead water composition at the Dinero and Nelson tunnels. The three end members were (1) a relatively dilute groundwater having low sulfate and trace element concentrations; (2) mine pool water, and (3) water that flowed from a structure in front of the bulkhead after bulkhead emplacement. Both (2) and (3) had high sulfate and trace element concentrations. These results indicate how analysis of monitoring information can be used to understand hydrogeochemical changes resulting from bulkhead emplacement. This understanding, in turn, can help inform future decisions on the disposition of the remaining mine waste and water-quality problems in the area.

Hydrology of an abandoned coal-mining area near McCurtain, Haskell County, Oklahoma

USGS Publications Warehouse

Slack, L.J.

1983-01-01

Water quality was investigated from October 1980 to May 1983 in an area of abandoned coal mines in Haskell county, Oklahoma. Bedrock in the area is shale, siltstone, sandstone, and the McAlester (Stigler) and Hartshorne coals of the McAlester Formation and Hartshorne Sandstone of Pennsylvanian age. The two coal beds, upper and lower Hartshorne, associated with the Hartshorne Sandstone converge or are separated by a few feet or less of bony coal or shale in the McCurtain area. Many small faults cut the Hartshorne coal in all the McCurtain-area mines. The main avenues of water entry to and movement through the bedrock are the exposed bedding-plane openings between layers of sandstone, partings between laminae of shale, fractures and joints developed during folding and faulting laminae of shale, fractures and joints developed during folding and faulting of the brittle rocks, and openings caused by surface mining--the overburden being shattered and broken to form spoil. Water-table conditions exist in bedrock and spoil in the area. Mine pond water is in direct hydraulic connections with water in the spoil piles and the underlying Hartshorne Sandstone. Sulfate is the best indicator of the presence of coal-mine drainage in both surface and ground water in the Oklahoma coal field. Median sulfate concentrations for four sites on Mule Creek ranged from 26 to 260 milligrams per liter. Median sulfate concentrations increased with increased drainage from unreclaimed mined areas. The median sulfate concentration in Mule Creek where it drains the reclaimed area is less than one-third of that at the next site downstream where the stream begins to drain abandoned (unreclaimed) mine lands. Water from Mule Creek predominantly is a sodium sulfate type. Maximum and median values for specific conductance and concentrations of calcium, magnesium, sodium, sulfate, chloride, dissolved solids, and alkalinity increase as Mule Creek flows downstream and drains increasing areas of abandoned (unreclaimed) mining lands. Constituent concentrations in Mule Creek, except those for dissolved solids, iron, manganese, and sulfate, generally do not exceed drinking-water limits. Reclamation likely would result in decreased concentrations of dissolved solids, calcium, magnesium, sodium, sulfate, and alkalinity in Mule Creek in the vicinity of the reclaimed area. Ground water in the area is moderately hard to very hard alkaline water with a median pH of 7.2 to 7.6. It predominately is a sodium sulfate type and, except for dissolved solids, iron manganese, and sulfate, constituent concentrations generally do not exceed drinking-water limits. Ground-water quality would likely be unchanged by reclamation. The quality of water in the two mine ponds is quite similar to that of the shallow ground water in the area. Constituents in water from both ponds generally do not exceed drinking-water limits and the water quality is unlikely to be changed by reclamation in the area.

Water quality data at selected sites in the Mississippi Valley-type Zn-Pb ore district of upper Silesia, Poland, 1995-97

USGS Publications Warehouse

Wirt, Laurie; Motyka, Jacek; Leach, David; Sass-Gustkiewicz, Maria; Szuwarzynski, Marek; Adamczyk, Zbigniew; Briggs, Paul; Meiers, Al

2003-01-01

The water chemistry of aquifers and streams in the Upper Silesia Ore District, Poland are affected by their proximity to zinc, lead, and silver ores and by ongoing mining activities that date back to the 11th century. This report presents hydrologic and water-quality data collected as part of a collaborative research effort of the U.S. Geological Survey and the University of Mining and Metallurgy in Cracow, Poland to study Mississippi-Valley-Type lead-zinc deposits. MVT deposits in the Upper Silesia Ore District (Fig. 1) were selected for detailed study because the Polish mining industry allowed access to collect samples from underground mines and mine-land property. Water-quality samples were collected from streams, springs, wells, underground mine seeps and drains; and mine-tailings ponds. Data include field measurements of specific conductance, pH, water temperature, and dissolved oxygen and laboratory analyses of major and minor inorganic constituents and selected trace-element constituents.

A simulation-based approach for estimating premining water quality: Red Mountain Creek, Colorado

USGS Publications Warehouse

Runkel, Robert L.; Kimball, Briant A; Walton-Day, Katherine; Verplanck, Philip L.

2007-01-01

Regulatory agencies are often charged with the task of setting site-specific numeric water quality standards for impaired streams. This task is particularly difficult for streams draining highly mineralized watersheds with past mining activity. Baseline water quality data obtained prior to mining are often non-existent and application of generic water quality standards developed for unmineralized watersheds is suspect given the geology of most watersheds affected by mining. Various approaches have been used to estimate premining conditions, but none of the existing approaches rigorously consider the physical and geochemical processes that ultimately determine instream water quality. An approach based on simulation modeling is therefore proposed herein. The approach utilizes synoptic data that provide spatially-detailed profiles of concentration, streamflow, and constituent load along the study reach. This field data set is used to calibrate a reactive stream transport model that considers the suite of physical and geochemical processes that affect constituent concentrations during instream transport. A key input to the model is the quality and quantity of waters entering the study reach. This input is based on chemical analyses available from synoptic sampling and observed increases in streamflow along the study reach. Given the calibrated model, additional simulations are conducted to estimate premining conditions. In these simulations, the chemistry of mining-affected sources is replaced with the chemistry of waters that are thought to be unaffected by mining (proximal, premining analogues). The resultant simulations provide estimates of premining water quality that reflect both the reduced loads that were present prior to mining and the processes that affect these loads as they are transported downstream. This simulation-based approach is demonstrated using data from Red Mountain Creek, Colorado, a small stream draining a heavily-mined watershed. Model application to the premining problem for Red Mountain Creek is based on limited field reconnaissance and chemical analyses; additional field work and analyses may be needed to develop definitive, quantitative estimates of premining water quality.

A 24 h investigation of the hydrogeochemistry of baseflow and stormwater in an urban area impacted by mining: Butte, Montana

USGS Publications Warehouse

Gammons, Christopher H.; Shope, Christopher L.; Duaime, Terence E.

2005-01-01

Changes in water quality during a storm event were continuously monitored over a 24 h period at a single location along an urban stormwater drain in Butte, Montana. The Butte Metro Storm Drain (MSD) collects groundwater baseflow and stormwater draining Butte Hill, a densely populated site that has been severely impacted by 130 years of mining, milling, and smelting of copper-rich, polymetallic mineral deposits. On the afternoon of 26 June 2002, a heavy thunderstorm caused streamflow in the MSD to increase 100-fold, from 0·2 ft3 s−1 to more than 20 ft3 s−1. Hourly discharge and water quality data were collected before, during, and following the storm. The most significant finding was that the calculated loads (grams per hour) of both dissolved and particulate copper passing down the MSD increased more than 100-fold in the first hour following the storm, and remained elevated over baseline conditions for the remainder of the study period. Other metals, such as zinc, cadmium, and manganese, showed a decrease in load from pre-storm to post-storm conditions. In addition to the large flush of copper, loads of soluble phosphorus increased during the storm, whereas dissolved oxygen dropped to low levels (<2 mg l−1). These results show that infrequent storm events in Butte have the potential to generate large volumes of runoff that exceed Montana water quality standards for acute exposure of aquatic life to copper, as well as depressed levels of dissolved oxygen. This study has important implications to ongoing reclamation activities in the upper Clark Fork Superfund site, particularly with respect to management of storm flow, and may be applicable to other watersheds impacted by mining activities.

Suspended sediment load below open-cast mines for ungauged river basin

NASA Astrophysics Data System (ADS)

Kuksina, L.

2011-12-01

Placer mines are located in river valleys along river benches or river ancient channels. Frequently the existing mining sites are characterized by low contribution of the environmental technologies. Therefore open-pit mining alters stream hydrology and sediment processes and enhances sediment transport. The most serious environmental consequences of the sediment yield increase occur in the rivers populated by salmon fish community because salmon species prefer clean water with low turbidity. For instance, placer mining located in Kamchatka peninsula (Far East of Russia) which is regarded to be the last global gene pool of wild salmon Oncorhynchus threatens rivers ecosystems significantly. Impact assessment is limited by the hydrological observations scarcity. Gauging network is rare and in many cases whole basins up to 200 km length miss any hydrological data. The main purpose of the work is elaboration of methods for sediment yield estimation in rivers under mining impact and implementation of corresponding calculations. Subjects of the study are rivers of the Vivenka river basin where open-cast platinum mine is situated. It's one of the largest platinum mines in Russian Federation and in the world. This mine is the most well-studied in Kamchatka (research covers a period from 2003 to 2011). Empirical - analytical model of suspended sediment yield estimation was elaborated for rivers draining mine's territories. Sediment delivery at the open-cast mine happens due to the following sediment processes: - erosion in the channel diversions; - soil erosion on the exposed hillsides; - effluent from settling ponds; - mine waste water inflow; - accident mine waste water escape into rivers. Sediment washout caused by erosion was estimated by repeated measurements of the channel profiles in 2003, 2006 and 2008. Estimation of horizontal deformation rates was carried out on the basis of erosion dependence on water discharge rates, slopes and composition of sediments. Soil erosion on the exposed hillsides was estimated taking into account precipitation of various intensity and solid material washout during this period. Effluent from settling ponds was calculated on the basis of minimum anthropogenic turbidity. Its value is difference in background turbidity and minimal turbidity caused by effluent and waste water overflow. Mine waste water inflow was estimated due to actual data on water balance of purification system. Accident mine waste water escape into rivers was estimated by duration and material washout during accidents data measured during observation period. Total suspended sediment yield of rivers draining mine's territory is the sum of its components. Total sediment supply from mining site is 24.7 % from the Vivenka sediment yield. Polluted placer-mined rivers contribute about 35.4 % of the whole sediment yield of the Vivenka river. At the same time the catchment area of these rivers is less than 0.2 % from the whole Vivenka catchment area.

Quantification of proportions of different water sources in a mining operation.

PubMed

Scheiber, Laura; Ayora, Carlos; Vázquez-Suñé, Enric

2018-04-01

The water drained in mining operations (galleries, shafts, open pits) usually comes from different sources. Evaluating the contribution of these sources is very often necessary for water management. To determine mixing ratios, a conventional mass balance is often used. However, the presence of more than two sources creates uncertainties in mass balance applications. Moreover, the composition of the end-members is not commonly known with certainty and/or can vary in space and time. In this paper, we propose a powerful tool for solving such problems and managing groundwater in mining sites based on multivariate statistical analysis. This approach was applied to the Cobre Las Cruces mining complex, the largest copper mine in Europe. There, the open pit water is a mixture of three end-members: runoff (RO), basal Miocene (Mb) and Paleozoic (PZ) groundwater. The volume of water drained from the Miocene base aquifer must be determined and compensated via artificial recharging to comply with current regulations. Through multivariate statistical analysis of samples from a regional field campaign, the compositions of PZ and Mb end-members were firstly estimated, and then used for mixing calculations at the open pit scale. The runoff end-member was directly determined from samples collected in interception trenches inside the open pit. The application of multivariate statistical methods allowed the estimation of mixing ratios for the hydrological years 2014-2015 and 2015-2016. Open pit water proportions have changed from 15% to 7%, 41% to 36%, and 44% to 57% for runoff, Mb and PZ end-members, respectively. An independent estimation of runoff based on the curve method yielded comparable results. Copyright © 2017 Elsevier B.V. All rights reserved.

Weathering of sulfidic shale and copper mine waste: Secondary minerals and metal cycling in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA

USGS Publications Warehouse

Hammarstrom, J.M.; Seal, R.R.; Meier, A.L.; Jackson, J.C.

2003-01-01

Metal cycling via physical and chemical weathering of discrete sources (copper mines) and regional (non-point) sources (sulfide-rich shale) is evaluated by examining the mineralogy and chemistry of weathering products in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA. The elements in copper mine waste, secondary minerals, stream sediments, and waters that are most likely to have negative impacts on aquatic ecosystems are aluminum, copper, zinc, and arsenic because these elements locally exceed toxicity guidelines for surface waters or for stream sediments. Acid-mine drainage has not developed in streams draining inactive copper mines. Acid-rock drainage and chemical weathering processes that accompany debris flows or human disturbances of sulfidic rocks are comparable to processes that develop acid-mine drainage elsewhere. Despite the high rainfall in the mountain range, sheltered areas and intermittent dry spells provide local venues for development of secondary weathering products that can impact aquatic ecosystems.

Remediation of acid mine drainage from the Santa Fe tin mine, Bolivia

NASA Astrophysics Data System (ADS)

Calvo, Daniel; Zamora Echenique, Gerardo; Alfonso, Pura; Casado, Jordi; Trujillo, Elvys; Jiménez-Franco, Abigail; Garcia-Valles, Maite

2015-04-01

The Santa Fe mine, department of Oruro, is located in the Andean Tin belt, is exploited for tin, zinc, lead and silver. This in an underground mine mined up to the -108 level. Today it is only mined up to the -50 level. Under this level the table water covers the mine. Water reaches the surface with a very acidic composition, with a high content in potentially toxic elements. This water drains directly to the Santa Fe River and contribute to the pollution present in this river that directly affect to the aquatic communities. In addition, population of this area have problems in the supply of drinking water, so remediation by obtaining cleaning water is a priority for this area. This study presents a neutralization-precipitation treatment with lime to the acid water inside the mine. The ore mineralogy of the Santa Fe mined deposit consists mainly in cassiterite, pyrite, sphalerite, galena, arsenopyrite argentite and sulphosalts. The host mineral is mainly quartz, with a minor content in feldspars and tourmaline. Alteration minerals as alunite, goethite and pumbojarosite are abundant and indicate the occurrence of reactions that lead to the formation of acid mine drainage. The mean pH of water drained from the Santa Fe mine is 2.2 and chemical analyses show high contents in potentially toxic elements: 27-295 ppm Zn, 0.05-0.2 ppm Pb, 0.06-0.09 ppm Cd, 04-0.12 ppm Cu, 113-165 ppm Fe, 4 ppm Mn and 564-664 ppm S. As and Sb were under 0.5 ppm. A settler tank inside the mine was designed by means of seal a selected gallery to clean the mine water. The function of this gallery is to sediment the sludge resulting from the neutralization - precipitation treatment process to obtain a clear water overflow continuously to the outside. The neutralization tests indicate that 0.65g/L of lime and 2ml of flocculant should be added to neutralize water up to pH 6-7. A flow rate of 80 L /s was considered. After a geotechnical study, a chamber located in the mine was selected to locate the settler. The volume of the settling tank was determined from sedimentation tests in order to obtain the adequate sedimentation time. According to these results and the availabolity of galleries the dimensions of the settler tank will be 160x1.8x1.9m. Sludges will be treated by a process of solidification and used to provide physical stability to the gallery. Acknowledgements: This work was partly financed by the project AECID: A3/042750/11, the SGR 2009SGR-00444 and the Centre de Cooperació al Desenvolupament (CCD-UPC).

Natural and mining-related sources of dissolved minerals during low flow in the Upper Animas River Basin, southwestern Colorado

USGS Publications Warehouse

Wright, Winfield G.

1997-01-01

As part of the Clean Water Act of 1972 (Public Law 92-500), all States are required to establish water-quality standards for every river basin in the State. During 1994, the Colorado Department of Public Health and Environment proposed to the Colorado Water Quality Control Commission (CWQCC) an aquatic-life standard of 225 µg/L (micrograms per liter) for the dissolved-zinc concentration in the Animas River downstream from Silverton (fig.1). The CWQCC delayed implementation of this water-quality standard until further information was collected and a plan for the cleanup of abandoned mines was developed. Dissolved-zinc concentrations in this section of the river ranged from about 270 µg/L during high flow, when rainfall and snowmelt runoff dilute the dissolved minerals in the river (U.S. Geological Survey, 1996, p. 431), to 960 µg/L (Colorado Department of Public Health and Environment, written commun., 1996) during low flow (such as late summer and middle winter when natural springs and drainage from mines are the main sources for the streams). Mining sites in the basin were developed between about 1872 and the 1940's, with only a few mines operated until the early 1990's. For local governments, mining sites represent part of the Nation's heritage, tourists are attracted to the historic mining sites, and governments are obligated to protect the historic mining sites according to the National Historic Preservation Act (Public Law 89-665). In the context of this fact sheet, the term "natural sources of dissolved minerals" refers to springs and streams where no effect from mining were determined. "Mining-related sources of dissolved minerals" are assumed to be: (1 ) Water draining from mines , and (2) water seeping from mine-waste dump pile where the waste piles were saturated by water draining from mines. Although rainfall and snowmelt runoff from mine-waste piles might affect water quality in streams, work described in this fact sheet was done during low-flow conditions when springs and drainage from mine were the main sources of dissolved minerals affecting the streams. Data are being collected by the U.S. Geological Survey (USGS) to determine the magnitude and sources of dissolved minerals during rainfall- and snowmelt-runoff periods. This fact sheet presents results of studies done by the USGS in collaboration with the Animas River Stakeholders Group and was prepared in cooperation with the Southwestern Colorado Water Conservation District. The studies were done at selected sites in the Upper Animas River Basin to determine natural and mining-related sources of dissolved minerals and are continuing in the basin with the Animas River Stakeholders Group and as part of the Department of the Interior Abandoned Mine Lands Initiative. The results of these studies will provide useful information for determining water-quality standards in the basin.

Map showing quarries, mines, prospects, and sample data in and near the James River Face Wilderness, Bedford and Rockbridge counties, Virginia

USGS Publications Warehouse

Gazdik, Gertrude C.; Ross, Robert B.

1982-01-01

The area, on the crest of the Blue Ridge Mountains, is drained by small tributaries of the James River.  Altitudes range from 600 ft where U.S. Route 501 crosses the James River to 3,073 ft on Highcock Knob.

Evolution of Microbial “Streamer” Growths in an Acidic, Metal-Contaminated Stream Draining an Abandoned Underground Copper Mine

PubMed Central

Kay, Catherine M.; Rowe, Owen F.; Rocchetti, Laura; Coupland, Kris; Hallberg, Kevin B.; Johnson, D. Barrie

2013-01-01

A nine year study was carried out on the evolution of macroscopic “acid streamer” growths in acidic, metal-rich mine water from the point of construction of a new channel to drain an abandoned underground copper mine. The new channel became rapidly colonized by acidophilic bacteria: two species of autotrophic iron-oxidizers (Acidithiobacillus ferrivorans and “Ferrovum myxofaciens”) and a heterotrophic iron-oxidizer (a novel genus/species with the proposed name “Acidithrix ferrooxidans”). The same bacteria dominated the acid streamer communities for the entire nine year period, with the autotrophic species accounting for ~80% of the micro-organisms in the streamer growths (as determined by terminal restriction enzyme fragment length polymorphism (T-RFLP) analysis). Biodiversity of the acid streamers became somewhat greater in time, and included species of heterotrophic acidophiles that reduce ferric iron (Acidiphilium, Acidobacterium, Acidocella and gammaproteobacterium WJ2) and other autotrophic iron-oxidizers (Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans). The diversity of archaea in the acid streamers was far more limited; relatively few clones were obtained, all of which were very distantly related to known species of euryarchaeotes. Some differences were apparent between the acid streamer community and planktonic-phase bacteria. This study has provided unique insights into the evolution of an extremophilic microbial community, and identified several novel species of acidophilic prokaryotes. PMID:25371339

Selenium Concentrations in Middle Pennsylvanian Coal-Bearing Strata in the Central Appalachian Basin

USGS Publications Warehouse

Neuzil, Sandra G.; Dulong, Frank T.; Cecil, C. Blaine; Fedorko, Nick; Renton, John J.; Bhumbla, D.K.

2007-01-01

Introduction This report provides the results of a reconnaissance-level investigation of selenium (Se) concentrations in Middle Pennsylvanian coal-bearing strata in the central Appalachian basin. Bryant and others (2002) reported enrichments of Se concentrations in streams draining areas disturbed by surface mining relative to Se concentrations in streams that drain undisturbed areas; the study was conducted without the benefit of data on Se concentrations in coal-bearing strata prior to anthropogenic disturbance. Thus, the present study was conducted to provide data on Se concentrations in coal-bearing strata prior to land disturbance. The principal objectives of this work are: 1) determine the stratigraphic and regional distribution of Se concentrations in coal-bearing strata, 2) provide reconnaissance-level information on relations, if any, between Se concentrations and lithology (rock-type), and 3) develop a cursory evaluation of the leachability of Se from disturbed strata. The results reported herein are derived from analyses of samples obtained from three widely-spaced cores that were collected from undisturbed rock within a region that has been subjected to extensive land disturbance principally by either coal mining or, to a lesser extent, highway construction. The focus was on low-organic-content lithologies, not coal, within the coal-bearing interval, as these lithologies most commonly make up the fill materials after coal mining or in road construction.

A120 yr record of widespread contamination from mining of the Iberian pyrite belt

USGS Publications Warehouse

VanGeen, A.; Adkins, J.F.; Boyle, E.A.; Nelson, C.H.; Palanques, A.

1997-01-01

A metal-enriched seawater plume entering the western Mediterranean Sea through the Strait of Gibraltar originates 300 km to the west in the Rio Tinto estuary of southwestern Spain. Mining of Rio Tinto ore, one of the largest metal-rich sulfide deposits in the world, started well before Roman times. Contemporary Rio Tinto waters draining the region are highly acidic (pH 2.5) with dissolved cadmium, zinc, and copper concentrations 105-106 times higher than in uncontaminated surface water of the Gulf of Cadiz. Two dated sediment cores from the Spanish continental shelf show that metal inputs to the region increased with the onset of intensive mining activities during the second half of the 19th century. Although the impact of mining may have decreased over the past few decades, the Tinto river and estuary remain highly contaminated.

Effects of historical coal mining and drainage from abandoned mines on streamflow and water quality in Bear Creek, Dauphin County, Pennsylvania-March 1999-December 2002

USGS Publications Warehouse

Chaplin, Jeffrey J.

2005-01-01

More than 100 years of anthracite coal mining has changed surface- and ground-water hydrology and contaminated streams draining the Southern Anthracite Coal Field in east-central Pennsylvania. Bear Creek drains the western prong of the Southern Anthracite Coal Field and is affected by metals in drainage from abandoned mines and streamwater losses. Total Maximum Daily Loads (TMDL) developed for dissolved iron of about 5 lb/d (pounds per day) commonly are exceeded in the reach downstream of mine discharges. Restoration of Bear Creek using aerobic ponds to passively remove iron in abandoned mine drainage is under consideration (2004) by the Dauphin County Conservation District. This report, prepared in cooperation with the Dauphin County Conservation District, evaluates chemical and hydrologic data collected in Bear Creek and its receiving waters prior to implementation of mine-drainage treatment. The data collected represent the type of baseline information needed for documentation of water-quality changes following passive treatment of mine drainage in Pennsylvania and in other similar hydrogeologic settings. Seven surface-water sites on Bear Creek and two mine discharges were monitored for nearly three years to characterize the chemistry and hydrology of the following: (1) Bear Creek upstream of the mine discharges (BC-UMD), (2) water draining from the Lykens-Williamstown Mine Pool at the Lykens Water-Level Tunnel (LWLT) and Lykens Drift (LD) discharges, (3) Bear Creek after mixing with the mine discharges (BC-DMD), and (4) Bear Creek prior to mixing with Wiconisco Creek (BCM). Two sites on Wiconisco Creek, upstream and downstream of Bear Creek (WC-UBC and WC-DBC, respectively), were selected to evaluate changes in streamflow and water quality upon mixing with Bear Creek. During periods of below-normal precipitation, streamwater loss was commonly 100 percent upstream of site BC-UMD (streamflow range = 0 to 9.7 ft3/s (cubic feet per second)) but no loss was detected downstream owing to sustained mine water drainage from the Lykens Water-Level Tunnel (range = 0.41 to 3.7 ft3/s), Lykens Drift (range = 0.40 to 6.1 ft3/s), and diffuse zones of seepage. Collectively, mine water inputs contributed about 84 percent of base flow and 53 percent of stormflow measured in the downstream reach. An option under consideration by the Dauphin County Conservation District for treatment of the discharge from the LWLT requires the source of the discharge to be captured and rerouted downstream, bypassing approximately 1,000 feet of stream channel. Because streamwater loss upstream of the tunnel was commonly 100 percent, rerouting the discharge from the LWLT may extend the reach of Bear Creek that is subject to dryness. Differences in the chemistry of water discharging from the LWLT compared to the LD suggest that the flow path through the Lykens-Williamstown Mine Pool to each mine discharge is unique. The LWLT is marginally alkaline (median net acid neutralizing capacity (ANC) = 9 mg/L (milligrams per liter) as CaCO3; median pH = 5.9), commonly becomes acidic (minimum net ANC = -74 mg/L as CaCO3) at low flow, and may benefit from alkaline amendments prior to passive treatment. Water discharging from the LD provides excess ANC (median net ANC = 123 mg/L as CaCO3; median pH = 6.5) to the downstream reach and is nearly anoxic at its source (median dissolved oxygen = 0.5 mg/L). Low dissolved oxygen water with relatively high ANC and metals concentrations discharging from the LD is characteristic of a deeper flow path and longer residence time within the mine pool than the more acidic, oxygenated water discharging from the LWLT. TMDLs for iron have been developed for dissolved species only. Consequently, distinguishing between dissolved and suspended iron in Bear Creek is important for evaluating water-quality improvement through TMDL attainment. Median total iron concentration increased from 550 mg/L (micrograms per liter) at site BC-UM

Increasing the Reliability of the Work of Artificial Filtering Arrays for the Purification of Quarry Waste Water

NASA Astrophysics Data System (ADS)

Tyulenev, Maxim; Lesin, Yury; Litvin, Oleg; Maliukhina, Elena; Abay, Asmelash

2017-11-01

Features of geological structure of the Kuznetsk coal basin stipulate the application of a low-cost open technique of coal mining, which is more advantageous both from the economic standpoint, and by safety criteria of mining. However, open mining affects significantly the water resources of region. Intensive pollution of reservoirs and water courses, exhaustion of the underground water-bearing layers, violation of a hydrographic network, etc. be-long to the main disadvantages of an open technique of coal mining. Besides, the volume of the water coming into the mining producers exceeds signi-ficantly the needed quantity. According to the data of annual reports of ecology and natural resources department, 348.277 million m3 of water were ta-ken away during production of soft coal, brown coal and lignum fossil from waters of Kemerovo region in 2013 (mostly from underground water objects (96,5%) when draining of mine openings). At the same time, only 87.018 million m3 of water (25%) has been used within a year.

Using imaging spectroscopy to map acidic mine waste

USGS Publications Warehouse

Swayze, G.A.; Smith, K.S.; Clark, R.N.; Sutley, S.J.; Pearson, R.M.; Vance, J.S.; Hageman, P.L.; Briggs, P.H.; Meier, A.L.; Singleton, M.J.; Roth, S.

2000-01-01

The process of pyrite oxidation at the surface of mine waste may produce acidic water that is gradually neutralized as it drains away from the waste, depositing different Fe-bearing secondary minerals in roughly concentric zones that emanate from mine-waste piles. These Fe-bearing minerals are indicators of the geochemical conditions under which they form. Airborne and orbital imaging spectrometers can be used to map these mineral zones because each of these Fe-bearing secondary minerals is spectrally unique. In this way, imaging spectroscopy can be used to rapidly screen entire mining districts for potential sources of surface acid drainage and to detect acid producing minerals in mine waste or unmined rock outcrops. Spectral data from the AVIRIS instrument were used to evaluate mine waste at the California Gulch Superfund Site near Leadville, CO. Laboratory leach tests of surface samples show that leachate pH is most acidic and metals most mobile in samples from the inner jarosite zone and that leachate pH is near-neutral and metals least mobile in samples from the outer goethite zone.

Mercury Release from the Rathburn Mine, Petray Mine, and Bear Valley Saline Springs, Colusa County, California 2004-2006

USGS Publications Warehouse

Slowey, Aaron J.; Rytuba, James J.

2008-01-01

This report summarizes data obtained from field sampling of mine tailings and waste rock at the Rathburn and Petray Mines that was initiated in July 17, 2001 and water and sediment in regional springs and tributaries that drain from the mine area into Bear Creek on December 14, 2004 and February 16 and May 27, 2005. Although it was initially assumed that the mines were the cause of elevated levels of monomethyl Hg measured by the Central Regional Water Quality Control Board in tributaries near their confluence with Bear Creek (Foe and others, unpublished results), it became apparent during this study that ground water springs were also potential sources of Hg. In addition to sampling of springs in May 2005, saline ground water seepage along an unnamed fault on the west side of Bear Valley was sampled on December 13-14, 2006. We did not sample water or sediment in Bear Creek itself during this study. Our results permit a preliminary assessment of mining and natural sources of Hg and associated chemical constituents that could elevate levels of monomethyl Hg in Bear Creek.

Mercury and arsenic in the gold mining regions of the Ankobra River basin in Ghana

NASA Astrophysics Data System (ADS)

Bannerman, W.; Potin-Gautier, M.; Amoureux, D.; Tellier, S.; Rambaud, A.; Babut, M.; Adimado, A.; Beinhoff, C.

2003-05-01

The river Ankobra flows through the principal gold mining centres in Western Ghana, draining a total area of 8272 km^2 to join the Atlantic ocean. Mercury is used by thousands of small-scale miners in the region to amalgamate gold. Ores mined in some deep shafts and surface mines are arsenopyrites and the region is marked by the presence of heaps of arsenic - rich mine tailings from both past and recent activities. This study was conducted to assess the impact of mining activities on the distribution and speciation of arsenic and mercury in the aquatic environment of the Ankobra River. In all, water (filtered and non-filtered) and bed sediments were collected from various locations within the watershed. Principal parameters investigated include total mercury, arsenic (III), arsenic (V), monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA). Seasonal and spatial variations of these parameters were investigated. Quality control systems were adopted at both the environmental and analytical stages of the study. ln general, areas close to the mining centres are the most pollilited. As (V)/As (III) ratios in water are reversed after the first 100-km of the river length with the onset of industrial influence downstream.

Influence of the Trojan Nickel Mine on surface water quality, Mazowe valley, Zimbabwe: Runoff chemistry and acid generation potential of waste rock

NASA Astrophysics Data System (ADS)

Lupankwa, Keretia; Love, David; Mapani, Benjamin; Mseka, Stephen; Meck, Maideyi

The impacts of mining on the environment depend on the nature of the ore body, the type of mining and the size of operation. The focus of this study is on Trojan Nickel Mine which is located 90 km north of Harare, Zimbabwe. It produces nickel from iron, iron-nickel and copper-nickel sulphides and disposes of waste rock in a rock dump. Surface water samples were taken at 11 points selected from a stream which drains the rock dump, a stream carrying underground water and the river into which these streams discharge. Samples were analysed for metals using atomic absorption spectrometry, for sulphates by gravitation and for carbonates and bicarbonates by back titration. Ninteen rock samples were collected from the dump and static tests were performed using the Sobek acid base accounting method. The results show that near neutral runoff (pH 7.0-8.5) with high concentrations of sulphate (over 100 mg/L) and some metals (Pb > 1.0 mg/L and Ni > 0.2 mg/L) emanates from the dump. This suggests that acid mine drainage is buffered in the dump (probably by carbonates). This is supported by the static tests, which show that the fine fraction of dump material neutralises acid. Runoff from the dump flows into a pond. Concentrations of sulphates and metals decrease after the dump runoff enters the pond, but sufficient remains to increase levels of calcium, sulphate, bicarbonate, iron and lead in the Pote River. The drop in concentrations at the pond indicates that the settling process has a positive effect on water quality. This could be enhanced by treating the pond water to raise pH, thus precipitating out metals and decreasing their concentrations in water draining from the pond.

Mercury and Methylmercury concentrations and loads in Cache Creek Basin, California, January 2000 through May 2001

USGS Publications Warehouse

Domagalski, Joseph L.; Alpers, Charles N.; Slotton, Darrell G.; Suchanek, Thomas H.; Ayers, Shaun M.

2004-01-01

Concentrations and mass loads of total mercury and methylmercury in streams draining abandoned mercury mines and near geothermal discharge in Cache Creek Basin, California, were measured during a 17-month period from January 2000 through May 2001. Rainfall and runoff averages during the study period were lower than long-term averages. Mass loads of mercury and methylmercury from upstream sources to downstream receiving waters, such as San Francisco Bay, were generally the highest during or after winter rainfall events. During the study period, mass loads of mercury and methylmercury from geothermal sources tended to be greater than those from abandoned mining areas because of a lack of large precipitation events capable of mobilizing significant amounts of either mercury-laden sediment or dissolved mercury and methylmercury from mine waste. Streambed sediments of Cache Creek are a source of mercury and methylmercury to downstream receiving bodies of water such as the Delta of the San Joaquin and Sacramento Rivers. Much of the mercury in these sediments was deposited over the last 150 years by erosion and stream discharge from abandoned mines or by continuous discharges from geothermal areas. Several geochemical constituents were useful as natural tracers for mining and geothermal areas. These constituents included aqueous concentrations of boron, chloride, lithium, and sulfate, and the stable isotopes of hydrogen and oxygen in water. Stable isotopes of water in areas draining geothermal discharges were enriched with more oxygen-18 relative to oxygen-16 than meteoric waters, whereas the enrichment by stable isotopes of water from much of the runoff from abandoned mines was similar to that of meteoric water. Geochemical signatures from stable isotopes and trace-element concentrations may be useful as tracers of total mercury or methylmercury from specific locations; however, mercury and methylmercury are not conservatively transported. A distinct mixing trend of trace elements and stable isotopes of hydrogen and oxygen from geothermal waters was apparent in Sulphur Creek and lower Bear Creek (tributaries to Cache Creek), but the signals are lost upon mixing with Cache Creek because of dilution.

Mercury and Methylmercury Related to Historical Mercury Mining in Three Major Tributaries to Lake Berryessa, Upper Putah Creek Watershed, California

NASA Astrophysics Data System (ADS)

Sparks, G. C.; Alpers, C. N.; Horner, T. C.; Cornwell, K.; Izzo, V.

2016-12-01

The relative contributions of total mercury (THg) and methylmercury (MeHg) from upstream historical mercury (Hg) mining districts were examined in the three largest tributaries to Lake Berryessa, a reservoir with water quality impaired by Hg. A fish consumption advisory has been issued for the reservoir; also, in a study of piscivorous birds at 25 California reservoirs, blood samples from Lake Berryessa grebes had the highest THg concentration state-wide. The third and fourth largest historical Hg-producing mining districts in California are within the study area. These mining districts are located within the Pope Creek, Upper Putah Creek, and Knoxville-Eticuera Creeks watersheds. Downstream of the reservoir, Lower Putah Creek drains into the Yolo Bypass, a major source of THg and MeHg to the Sacramento-San Joaquin Delta. Study objectives included: (1) determining if tributaries downstream of historical Hg mining districts and draining to the reservoir are continuing sources of THg and MeHg; (2) characterizing variability of water and streambed sediment parameters in upstream and downstream reaches of each creek; and (3) estimating loads of suspended sediment, THg, and MeHg entering the reservoir from each tributary. Water samples were collected from October 2012 to September 2014 during non-storm and storm events along each tributary and analyzed for general water quality field parameters; unfiltered THg and MeHg; total suspended solids; and total particulate matter. Discharge measurements were made at the time of sample collection; flow and concentration data were combined to compute daily loads. To determine spatial variability, 135 streambed sediment samples were analyzed for THg, organic content (loss on ignition), and grain-size distribution. All three tributaries contribute THg and MeHg to the reservoir. Some consistent spatial trends in THg (water) concentrations were observed over multiple sampling events; THg (water) decreased from upstream to downstream in all three tributaries. Tributary reaches with elevated THg in streambed sediment ("Hg hot spots") are near or downstream from historical Hg mines and Hg-enriched ore deposits. Future Hg load and cycling studies are needed to identify practical remediation approaches for decreasing THg and MeHg loads to Lake Berryessa.

Generation of acid mine drainage around the Karaerik copper mine (Espiye, Giresun, NE Turkey): implications from the bacterial population in the Acısu effluent.

PubMed

Sağlam, Emine Selva; Akçay, Miğraç; Çolak, Dilşat Nigar; İnan Bektaş, Kadriye; Beldüz, Ali Osman

2016-09-01

The Karaerik Cu mine is a worked-out deposit with large volumes of tailings and slags which were left around the mine site without any protection. Natural feeding of these material and run-off water from the mineralised zones into the Acısu effluent causes a serious environmental degradation and creation of acid mine drainage (AMD) along its entire length. This research aims at modelling the formation of AMD with a specific attempt on the characterisation of the bacterial population in association with AMD and their role on its occurrence. Based on 16SrRNA analyses of the clones obtained from a composite water sample, the bacterial community was determined to consist of Acidithiobacillus ferrivorans, Ferrovum myxofaciens, Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans as iron-oxidising bacteria, Acidocella facilis, Acidocella aluminiidurans, Acidiphilium cryptum and Acidiphilium multivorum as iron-reducing bacteria, and Acidithiobacillus ferrivorans, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidiphilium cryptum as sulphur-oxidising bacteria. This association of bacteria with varying roles was interpreted as evidence of a concomitant occurrence of sulphur and iron cycles during the generation of AMD along the Acısu effluent draining the Karaerik mine.

Geomorphic reclmation of a coal refuse pile

NASA Astrophysics Data System (ADS)

Hopkinson, L. C.; Quaranta, J.

2017-12-01

Geomorphic reclamation is a technique that may offer opportunities to improve mine reclamation in Central Appalachia. The design approach is based on constructing a steady-state, mature landform condition and takes into account the long-term climatic conditions, soil types, terrain grade, and vegetation. Geomorphic reclamation has been applied successfully in semi-arid regions but has not yet been applied in Central Appalachia. This work describes a demonstration study where geomorphic landforming techniques are being applied to a coarse coal refuse pile in southern West Virginia, USA. The reclamation design includes four geomorphic watersheds that radially drain runoff from the pile. Each watershed has one central draining channel and incorporates compound slope profiles similarly to naturally eroded slopes. Planar slopes were also included to maintain the impacted area. The intent is to alter the hydrology to decrease water quality treatment costs. The excavation cut and fill volumes are comparable to those of more conventional refuse pile reclamation designs. If proven successful then this technique can be part of a cost-effective solution to improve water quality at active and future refuse facilities, abandoned mine lands, bond forfeiture sites, landfills, and major earthmoving activities within the region.

Widespread waterborne pollution in central Swedish lakes and the Baltic Sea from pre-industrial mining and metallurgy.

PubMed

Bindler, Richard; Renberg, Ingemar; Rydberg, Johan; Andrén, Thomas

2009-07-01

Metal pollution is viewed as a modern problem that began in the 19th century and accelerated through the 20th century; however, in many parts of the globe this view is wrong. Here, we studied past waterborne metal pollution in lake sediments from the Bergslagen region in central Sweden, one of many historically important mining regions in Europe. With a focus on lead (including isotopes), we trace mining impacts from a local scale, through a 120-km-long river system draining into Mälaren--Sweden's third largest lake, and finally also the Baltic Sea. Comparison of sediment and peat records shows that pollution from Swedish mining was largely waterborne and that atmospheric deposition was dominated by long-range transport from other regions. Swedish ore lead is detectable from the 10th century, but the greatest impact occurred during the 16th-18th centuries with improvements occurring over recent centuries, i.e., historical pollution > modern industrial pollution.

Mine drainage water from the Sar Cheshmeh porphyry copper mine, Kerman, IR Iran.

PubMed

Shahabpour, J; Doorandish, M

2008-06-01

This paper presents the results of a study on stream and mine waters in the area of one of the world largest porphyry copper deposit located in the southeastern Iran, the Sar Cheshmeh porphyry copper mine. Trace metals are present as adsorption on Fe and Mn oxide and hydroxide particles, as sulfate, simple metal ions, and scarcely as adsorption on clay particles and hydrous aluminium oxides. Mean pH decreases and the mean concentration of trace elements, EC and SO4(2-) increases from the maximum discharge period (MXDP) during snow melt run off (May), through the moderate discharge period (MDDP; March and July) to the minimum discharge period (MNDP; September). Water samples have sulfatic character essentially, however, from the MNDP through the MDDP towards the MXDP they show a bicarbonate tendency. This study indicates that the surface waters draining the Sar Cheshmeh open pit have a higher pH and lower concentration of trace metals compared with some other porphyry copper deposits.

Maps showing mines, quarries, prospects, and exposures in the Devils Fork Roadless Area, Scott County, Virginia

USGS Publications Warehouse

Behum, Paul T.

1984-01-01

The Devils Fork Roadless Area is located at the eastern edge of the Appalachian coal region and is within the Cumberland Mountain section of the Appalachian Plateau physiographic province. Most of the area is drained by Devil Fork and its tributaries. Clinch Rock Branch of Straight Creek, Roddy Branch of Valley Creek, and Stinking Creek, all tributary to the Clinch River, drain small fringe tracts. Altitudes range from about 1,550 ft on the lower part of Straight Fork to about 3,490 ft at Cox Place on Little Mountain. Vegetation varies from mixed hardwoods in the uplands to thickets of conifer, rhododendron, and laurel in moist protected areas, as in coves along drainage courses.

Mercury and methylmercury contents in mine-waste calcine, water, and sediment collected from the Palawan Quicksilver mine, Philippines

USGS Publications Warehouse

Gray, J.E.; Greaves, I.A.; Bustos, D.M.; Krabbenhoft, D.P.

2003-01-01

The Palawan Quicksilver mine, Philippines, produced about 2,900 t of mercury during mining of cinnabar ore from 1953 to 1976. More than 2,000,000 t of mine-waste calcines (retorted ore) were produced during mining, much of which were used to construct a jetty in nearby Honda Bay. Since 1995, high Hg contents have been found in several people living near the mine, and 21 of these people were treated for mercury poisoning. Samples of mine-waste calcine contain high total Hg concentrations ranging from 43-660 ??g/g, whereas total Hg concentrations in sediment samples collected from a mine pit lake and local stream vary from 3.7-400 ??g/g. Mine water flowing through the calcines is acidic, pH 3.1-4.3, and total Hg concentrations ranging from 18-31 ??g/l in this water significantly exceed the 1.0-??g/l drinking water standard for Hg recommended by the World Health Organization (WHO). Total Hg contents are generally lower in water samples collected from surrounding domestic wells, the mine pit lake, Honda Bay, and the nearby stream, varying from 0.008-1.4 ??g/l. Methylmercury concentrations in water draining mine calcines range from <0.02-1.4 ng/l, but methylmercury is highest in the pit lake water, ranging from 1.7-3.1 ng/l. Mercury methylation at the Palawan mine is similar to or higher than that found in other mercury mines worldwide. Much of the methylmercury generated in Palawan mine-waste calcines and those in Honda Bay is transferred to water, and then to marine fish and seafood. A food source pathway of Hg to humans is most likely in this coastal, high fish-consuming population.

Spatial and temporal relationships among watershed mining, water quality, and freshwater mussel status in an eastern USA river.

PubMed

Zipper, Carl E; Donovan, Patricia F; Jones, Jess W; Li, Jing; Price, Jennifer E; Stewart, Roger E

2016-01-15

The Powell River of southwestern Virginia and northeastern Tennessee, USA, drains a watershed with extensive coal surface mining, and it hosts exceptional biological richness, including at-risk species of freshwater mussels, downstream of mining-disturbed watershed areas. We investigated spatial and temporal patterns of watershed mining disturbance; their relationship to water quality change in the section of the river that connects mining areas to mussel habitat; and relationships of mining-related water constituents to measures of recent and past mussel status. Freshwater mussels in the Powell River have experienced significant declines over the past 3.5 decades. Over that same period, surface coal mining has influenced the watershed. Water-monitoring data collected by state and federal agencies demonstrate that dissolved solids and associated constituents that are commonly influenced by Appalachian mining (specific conductance, pH, hardness and sulfates) have experienced increasing temporal trends from the 1960s through ~2008; but, of those constituents, only dissolved solids concentrations are available widely within the Powell River since ~2008. Dissolved solids concentrations have stabilized in recent years. Dissolved solids, specific conductance, pH, and sulfates also exhibited spatial patterns that are consistent with dilution of mining influence with increasing distance from mined areas. Freshwater mussel status indicators are correlated negatively with dissolved solids concentrations, spatially and temporally, but the direct causal mechanisms responsible for mussel declines remain unknown. Copyright © 2015 Elsevier B.V. All rights reserved.

Environmental risk assessment of lead-zinc mining: a case study of Adudu metallogenic province, middle Benue Trough, Nigeria.

PubMed

Igwe, Ogbonnaya; Una, Chuku Okoro; Abu, Ezekiel; Adepehin, Ekundayo Joseph

2017-09-07

Assessment of the impacts of lead-zinc mining in Adudu-Imon metallogenic province was carried out. Reconnaissance and detailed field studies were done. Lithologies, stream sediments, farmland soils, mine tailings, artificial pond water, stream water, well water, and borehole water were collected and subjected to atomic absorption spectrometry (AAS) and X-ray fluorescence (XRF) analyses. Geochemical maps were generated using ArcGIS 10.1. Significant contamination with cadmium (Cd), iron (Fe), and lead (Pb) was recorded in the collected water samples. Virtually all collected soil samples were observed to be highly contaminated when compared with the European Union environmental policy standard. The discharge of mining effluents through farmlands to the Bakebu stream, which drains the area, further exposes the dwellers of this environment to the accumulation of potentially harmful metals (PHMs) in their bodies through the consumption of food crops, aquatic animals, and domestic uses of the water collected from the stream channels. The study revealed non-conformity of past mining operations in the Adudu-Imon province to existing mining laws in Nigeria. Inhabitants of this region should stop farming in the vicinity of the mines, fishing from the Bakebu stream channels should be discouraged, and domestic use of the water should be condemned, even as concerned government agencies put necessary mercenaries in place to ensure conformity of miners to standard mining regulations in Nigeria.

Effects of potential surface coal mining on dissolved solids in Otter Creek and in the Otter Creek alluvial aquifer, southeastern Montana

USGS Publications Warehouse

Cannon, M.R.

1985-01-01

Otter Creek drains an area of 709 square miles in the coal-rich Powder River structural basin of southeastern Montana. The Knobloch coal beds in the Tongue River Member of the Paleocene Fort Union Formation is a shallow aquifer and a target for future surface mining in the downstream part of the Otter Creek basin. A mass-balance model was used to estimate the effects of potential mining on the dissolved solids concentration in Otter Creek and in the alluvial aquifer in the Otter Creek valley. With extensive mining of the Knobloch coal beds, the annual load of dissolved solids to Otter Creek at Ashland at median streamflow could increase by 2,873 tons, or a 32-percent increase compared to the annual pre-mining load. Increased monthly loads of Otter Creek, at the median streamflow, could range from 15 percent in February to 208 percent in August. The post-mining dissolved solids load to the subirrigated part of the alluvial valley could increase by 71 percent. The median dissolved solids concentration in the subirrigated part of the valley could be 4,430 milligrams per liter, compared to the pre-mining median concentration of 2,590 milligrams per liter. Post-mining loads from the potentially mined landscape were calculated using saturated-paste-extract data from 506 overburdened samples collected from 26 wells and test holes. Post-mining loads to the Otter Creek valley likely would continue at increased rates for hundreds of years after mining. If the actual area of Knobloch coal disturbed by mining were less than that used in the model, post-mining loads to the Otter Creek valley would be proportionally smaller. (USGS)

Tree rings record 100 years of hydrologic change within a wetland

USGS Publications Warehouse

Yanosky, Thomas M.; Kappel, William M.

1997-01-01

Hydrology and tree growth were investigated within a small wetland in the Tully Valley of central New York, about 20 miles south of Syracuse. In late 1994 it was noted that some wetland trees were dying, and local residents reported that flow of a small stream draining the wetland seemingly increased and became more brackish since the mid to late 1980s. The wetland is about 3 miles north of an extensive salt mining operation known to have degraded local water quality, but no effects of mining had been confirmed previously near the wetland. The oldest wetland trees started to grow before the onset of mining in 1889, and thus tree-ring studies were undertaken not only to investi-gate recent hydrologic change within the wetland, but also to search for evidence of any other changes during the last 100 years.

Speciation and Release Kinetics of Cadmium in an Alkaline Paddy Soil Under Various Flooding Periods and Draining Conditions

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

S Khaokaew; R Chaney; G Landrot

2011-12-31

This study determined Cd speciation and release kinetics in a Cd-Zn cocontaminated alkaline paddy soil, under various flooding periods and draining conditions, by employing synchrotron-based techniques, and a stirred-flow kinetic method. Results revealed that varying flooding periods and draining conditions affected Cd speciation and its release kinetics. Linear least-squares fitting (LLSF) of bulk X-ray absorption fine structure (XAFS) spectra of the air-dried, and the 1 day-flooded soil samples, showed that at least 50% of Cd was bound to humic acid. Cadmium carbonates were found as the major species at most flooding periods, while a small amount of cadmium sulfide wasmore » found after the soils were flooded for longer periods. Under all flooding and draining conditions, at least 14 mg/kg Cd was desorbed from the soil after a 2-hour desorption experiment. The results obtained by micro X-ray fluorescence ({mu}-XRF) spectroscopy showed that Cd was less associated with Zn than Ca, in most soil samples. Therefore, it is more likely that Cd and Ca will be present in the same mineral phases rather than Cd and Zn, although the source of these two latter elements may originate from the same surrounding Zn mines in the Mae Sot district.« less

Ecological impacts of lead mining on Ozark streams: toxicity of sediment and pore water.

PubMed

Besser, John M; Brumbaugh, William G; Allert, Ann L; Poulton, Barry C; Schmitt, Christopher J; Ingersoll, Christopher G

2009-02-01

We studied the toxicity of sediments downstream of lead-zinc mining areas in southeast Missouri, using chronic sediment toxicity tests with the amphipod, Hyalella azteca, and pore-water toxicity tests with the daphnid, Ceriodaphnia dubia. Tests conducted in 2002 documented reduced survival of amphipods in stream sediments collected near mining areas and reduced survival and reproduction of daphnids in most pore waters tested. Additional amphipod tests conducted in 2004 documented significant toxic effects of sediments from three streams downstream of mining areas: Strother Creek, West Fork Black River, and Bee Fork. Greatest toxicity occurred in sediments from a 6-km reach of upper Strother Creek, but significant toxic effects occurred in sediments collected at least 14 km downstream of mining in all three watersheds. Toxic effects were significantly correlated with metal concentrations (nickel, zinc, cadmium, and lead) in sediments and pore waters and were generally consistent with predictions of metal toxicity risks based on sediment quality guidelines, although ammonia and manganese may also have contributed to toxicity at a few sites. Responses of amphipods in sediment toxicity tests were significantly correlated with characteristics of benthic invertebrate communities in study streams. These results indicate that toxicity of metals associated with sediments contributes to adverse ecological effects in streams draining the Viburnum Trend mining district.

Impact of AMD on water quality in critical watershed in the Hudson River drainage basin: Phillips Mine, Hudson Highlands, New York

USGS Publications Warehouse

Gilchrist, S.; Gates, A.; Szabo, Z.; Lamothe, P.J.

2009-01-01

A sulfur and trace element enriched U-Th-laced tailings pile at the abandoned Phillips Mine in Garrison, New York, releases acid mine drainage (AMD, generally pH < 3, minimum pH 1.78) into the first-order Copper Mine Brook (CMB) that drains into the Hudson River. The pyrrhotite-rich Phillips Mine is located in the Highlands region, a critical water source for the New York metro area. A conceptual model for derivation/dissolution, sequestration, transport and dilution of contaminants is proposed. The acidic water interacts with the tailings, leaching and dissolving the trace metals. AMD evaporation during dry periods concentrates solid phase trace metals and sulfate, forming melanterite (FeSO4.7H2O) on sulfide-rich tailings surfaces. Wet periods dissolve these concentrates/precipitates, releasing stored acidity and trace metals into the CMB. Sediments along CMB are enriched in iron hydroxides which act as sinks for metals, indicating progressive sequestration that correlates with dilution and sharp rise in pH when mine water mixes with tributaries. Seasonal variations in metal concentrations were partly attributable to dissolution of the efflorescent salts with their sorbed metals and additional metals from surging acidic seepage induced by precipitation.

Ecological impacts of lead mining on Ozark streams: Toxicity of sediment and pore water

USGS Publications Warehouse

Besser, J.M.; Brumbaugh, W.G.; Allert, A.L.; Poulton, B.C.; Schmitt, C.J.; Ingersoll, C.G.

2009-01-01

We studied the toxicity of sediments downstream of lead-zinc mining areas in southeast Missouri, using chronic sediment toxicity tests with the amphipod, Hyalella azteca, and pore-water toxicity tests with the daphnid, Ceriodaphnia dubia. Tests conducted in 2002 documented reduced survival of amphipods in stream sediments collected near mining areas and reduced survival and reproduction of daphnids in most pore waters tested. Additional amphipod tests conducted in 2004 documented significant toxic effects of sediments from three streams downstream of mining areas: Strother Creek, West Fork Black River, and Bee Fork. Greatest toxicity occurred in sediments from a 6-km reach of upper Strother Creek, but significant toxic effects occurred in sediments collected at least 14 km downstream of mining in all three watersheds. Toxic effects were significantly correlated with metal concentrations (nickel, zinc, cadmium, and lead) in sediments and pore waters and were generally consistent with predictions of metal toxicity risks based on sediment quality guidelines, although ammonia and manganese may also have contributed to toxicity at a few sites. Responses of amphipods in sediment toxicity tests were significantly correlated with characteristics of benthic invertebrate communities in study streams. These results indicate that toxicity of metals associated with sediments contributes to adverse ecological effects in streams draining the Viburnum Trend mining district.

Spatial Variation and Assessment of Heavy Metal and Radioactive Risk in Farmland around a Retired Uranium Mine

NASA Astrophysics Data System (ADS)

Liang, Jie; Shi, Chen-hao; Zeng, Guang-ming; Zhong, Min-zhou; Yuan, Yu-jie

2017-07-01

In recent years, heavy metal contamination in the environment has been attracted worldwide attention due to their toxicity, persistence,extensive sources and non-biodegradable properties. We herein investigate variation trend and risk of heavy metal and radiation distribution in the former mine stope, former mineral ore stockyard, and mine road with surface soils of a retired uranium mine in the mid-south of China. The mean concentrations (mg/kg) of Pb,Cd,Cu,Zn,As,Hg,Cr,Mn,Ni,U, and 232Th were analyzed according to the corresponding background values in Hunan, China. The Geo-accumulation index (Igeo ) were used for the assessment of pollution level of heavy metals and the radioactive elements of U and 232Th. Then, Pollution load index (PLI) and GIS techniquewere integrated to assess spatial distribution of heavy metal contamination and radioactive contamination. Results confirmed that three areas in the retired uranium mine was a primary source of pollution, which showed anthropogenic origin mainly from agricultural runoff, hydrometallurgy from chemical industries, radioactive tailings, and electroplating industriesfinally drained into Zishui River and Xiangjiang River. Based on the actual situation, some suggestions were put forward for the treatment of the retired uranium mine in conclusion.

Effects of historical lead–zinc mining on riffle-dwelling benthic fish and crayfish in the Big River of southeastern Missouri, USA

USGS Publications Warehouse

Allert, A.L.; DiStefano, R.J.; Fairchild, J.F.; Schmitt, C.J.; McKee, M.J.; Girondo, J.A.; Brumbaugh, W.G.; May, T.W.

2013-01-01

The Big River (BGR) drains much of the Old Lead Belt mining district (OLB) in southeastern Missouri, USA, which was historically among the largest producers of lead–zinc (Pb–Zn) ore in the world. We sampled benthic fish and crayfish in riffle habitats at eight sites in the BGR and conducted 56-day in situ exposures to the woodland crayfish (Orconectes hylas) and golden crayfish (Orconectes luteus) in cages at four sites affected to differing degrees by mining. Densities of fish and crayfish, physical habitat and water quality, and the survival and growth of caged crayfish were examined at sites with no known upstream mining activities (i.e., reference sites) and at sites downstream of mining areas (i.e., mining and downstream sites). Lead, zinc, and cadmium were analyzed in surface and pore water, sediment, detritus, fish, crayfish, and other benthic macro-invertebrates. Metals concentrations in all materials analyzed were greater at mining and downstream sites than at reference sites. Ten species of fish and four species of crayfish were collected. Fish and crayfish densities were significantly greater at reference than mining or downstream sites, and densities were greater at downstream than mining sites. Survival of caged crayfish was significantly lower at mining sites than reference sites; downstream sites were not tested. Chronic toxic-unit scores and sediment probable effects quotients indicated significant risk of toxicity to fish and crayfish, and metals concentrations in crayfish were sufficiently high to represent a risk to wildlife at mining and downstream sites. Collectively, the results provided direct evidence that metals associated with historical mining activities in the OLB continue to affect aquatic life in the BGR.

Sources and fates of heavy metals in a mining-impacted stream: Temporal variability and the role of iron oxides

PubMed Central

Schaider, Laurel A.; Senn, David B.; Estes, Emily R.; Brabander, Daniel J.; Shine, James P.

2014-01-01

Heavy metal contamination of surface waters at mining sites often involves complex interactions of multiple sources and varying biogeochemical conditions. We compared surface and subsurface metal loading from mine waste pile runoff and mine drainage discharge and characterized the influence of iron oxides on metal fate along a 0.9-km stretch of Tar Creek (Oklahoma, USA), which drains an abandoned Zn/Pb mining area. The importance of each source varied by metal: mine waste pile runoff contributed 70% of Cd, while mine drainage contributed 90% of Pb, and both sources contributed similarly to Zn loading. Subsurface inputs accounted for 40% of flow and 40-70% of metal loading along this stretch. Streambed iron oxide aggregate material contained highly elevated Zn (up to 27,000 μg g−1), Pb (up to 550 μg g−1) and Cd (up to 200 μg g−1) and was characterized as a heterogeneous mixture of iron oxides, fine-grain mine waste, and organic material. Sequential extractions confirmed preferential sequestration of Pb by iron oxides, as well as substantial concentrations of Zn and Cd in iron oxide fractions, with additional accumulation of Zn, Pb, and Cd during downstream transport. Comparisons with historical data show that while metal concentrations in mine drainage have decreased by more than an order of magnitude in recent decades, the chemical composition of mine waste pile runoff has remained relatively constant, indicating less attenuation and increased relative importance of pile runoff. These results highlight the importance of monitoring temporal changes at contaminated sites associated with evolving speciation and simultaneously addressing surface and subsurface contamination from both mine waste piles and mine drainage. PMID:24867708

An assessment of The Effects of Elevation and Aspect on Deposition of Airborne Pollution and Water Quality in an Alpine Critical Zone: San Juan Mountains, Colorado, USA

NASA Astrophysics Data System (ADS)

Price, A.; Giardino, J. R.; Marcantonio, F.

2015-12-01

The alpine critical zone is affected by various inputs, storages, pathways, and outputs. Unfortunately, many of these processes distribute the pollutants beyond the immediate area and into the surrounding biological and anthropogenic communities. Years of mining and improper disposal of the tailings and acid-mine drainage have degraded the quality of surface water within the San Juan Mountains. However, mining may not be the only factor significantly affecting the surface water quality in this high-elevation environment. As a high elevation system, this area is a fragile ecosystem with inputs ranging from local mining to atmospheric transport and deposition. Studies from around the world have shown atmospheric transport and deposition affect high-elevation systems. Thus, a significant question arises: does elevation or aspect affect the volume and rate of atmospheric deposition of pollutants? We assume atmospheric deposition occurs on the slopes in addition to in streams, lakes, and ponds. Deposition on slopes can be transported to nearby surface waters and increase the impact of the atmospheric pollutants along with residence time. Atmospheric deposition data were collected for aluminum, iron, manganese, nitrate, phosphate, and sulfate. Water chemistry data were collected for the same constituents as the atmospheric deposition with the addition of temperature, dissolved oxygen, pH, and specific conductance. Deposition samples were collected on a five-day sampling regime during two summers. Water quality samples were collected in-stream adjacent to the deposition-ample collectors. Collection sites were located on opposite sides of Red Mountain at five equal elevations providing two different aspects. The north side is drained by Red Mountain Creek and the south side is drained by Mineral Creek. Differences in atmospheric deposition and water quality at different elevations and aspects suggest there is a relationship between aspect and elevation on atmospheric pollution deposition. It is suggested that degradation of water quality in the San Juan Mountains is affected by atmospheric deposition along with the damage sustained from local mining activities. These results facilitate a better understanding of this high-elevation critical-zone system.

Influence of Geological Structure on Coal and Gas Outburst Occurrences in Turkish Underground Coal Mines

NASA Astrophysics Data System (ADS)

Esen, Olgun; Özer, Samet Can; Fişne, Abdullah

2015-04-01

Coal and gas outbursts are sudden and violent releases of gas and in company with coal that result from a complex function of geology, stress regime with gas pressure and gas content of the coal seam. The phenomena is referred to as instantaneous outbursts and have occurred in virtually all the major coal producing countries and have been the cause of major disasters in the world mining industry. All structures from faults to joints and cleats may supply gas or lead to it draining away. Most geological structures influence the way in which gas can drain within coal seams. From among all the geological factors two groups can be distinguished: parameters characterising directly the occurrence and geometry of the coal seams; parameters characterising the tectonic disturbances of the coal seams and neighbouring rocks. Also dykes may act as gas barriers. When the production of the coal seam is advanced in mine working areas, these barriers are failed mostly in the weak and mylonitized zones. Geology also plays a very important role in the outburst process. Coal seams of complex geological structure including faults, folds, and fractured rocks are liable to outbursts if coal seams and neighbouring rocks have high gas content level. The purpose of the study is to enlighten the coal industry in Turkey to improving mine safety in underground coal production and decrease of coal and gas outburst events due to increasing depth of mining process. In Turkey; the years between 1969 and 2013, the number of 90 coal and gas outbursts took place in Zonguldak Hard Coal Basin in both Kozlu and Karadon Collieries. In this study the liability to coal and gas outburst of the coal seams are investigated by measuring the strength of coal and the rock pressure. The correlation between these measurements and the event locations shows that the geological structures resulted in 52 events out of 90 events; 19 events close to the fault zones, 25 events thorough the fault zones and 8 events in the zones where sudden changes of inclination and/or thickness of the coal seam.

Acid mine drainage in the Iberian Pyrite Belt: 1. Hydrochemical characteristics and pollutant load of the Tinto and Odiel rivers.

PubMed

Nieto, Jose M; Sarmiento, Aguasanta M; Canovas, Carlos R; Olias, Manuel; Ayora, Carlos

2013-11-01

Acid mine drainage in the Iberian Pyrite Belt is probably the worst case in the world of surface water pollution associated with mining of sulphide mineral deposits. The Iberian Pyrite Belt is located in SW Iberian Peninsula, and it has been mined during the last 4,500 years. The central and eastern part of the Iberian Pyrite Belt is drained by the Tinto and Odiel rivers, which receive most of the acidic leachates from the mining areas. As a result, the main channels of the Tinto and Odiel rivers are very rich in metals and highly acidic until reaching the Atlantic Ocean. A significant amount of the pollutant load transported by these two rivers is delivered during the rainy season, as is usual in rivers of Mediterranean climate regions. Therefore, in order to have an accurate estimation of the pollutant loads transported by the Tinto and Odiel rivers, a systematic sampling on a weekly basis and a high temporal resolution sampling of floods events were both performed. Results obtained show that metal fluxes are strongly dependent on the study period, highlighting the importance of inter-annual studies involving dry and wet years.

Environmental Impact of the Contact and Sonoma Mercury Mines on Water, Sediment, and Biota in Anna Belcher and Little Sulphur Creek Watersheds, Sonoma County, California

USGS Publications Warehouse

Rytuba, James J.; Hothem, Roger L.; May, Jason T.; Kim, Christopher S.; Lawler, David; Goldstein, Daniel

2009-01-01

The Contact and Sonoma mercury (Hg) deposits are among the youngest Hg deposits in the Coast Range Hg mineral belt and are located in the western part of the Clear Lake volcanic field in Sonoma County, California. The mine workings and tailings are located in the headwaters of Anna Belcher Creek, which is a tributary to Little Sulphur Creek. The Contact Hg mine produced about 1,000 flasks of Hg, and the Sonoma mine produced considerably less. Waste rock and tailings eroded from the Contact and Sonoma mines have contributed Hg-enriched mine waste material to the headwaters of Anna Belcher Creek. The mines are located on federal land managed by the U.S. Bureau of Land Management (USBLM). The USBLM requested that the U.S. Geological Survey (USGS) measure and characterize Hg and other geochemical constituents in tailings, sediment, water, and biota at the Contact and Sonoma mines and in Anna Belcher and Little Sulphur Creeks. This report is made in response to the USBLM request, the lead agency mandated to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - Removal Site Investigation (RSI). The RSI applies to removal of Hg-contaminated mine waste from the Contact and Sonoma mines as a means of reducing Hg transport to Anna Belcher and Little Sulphur Creeks. This report summarizes data obtained from field sampling of mine tailings, waste rock, sediment, and water at the Contact and Sonoma mines that was initiated on April 20 during a storm event, and on June 19, 2001. Further sampling of water, sediment, and biota in a pond and tributaries that drain from the mine area was completed on April 1, 2003. Our results permit a preliminary assessment of the mining sources of Hg and associated chemical constituents that could elevate levels of monomethyl Hg (MMeHg) in tributaries and biota that are impacted by historic mining.

Long-Term Changes In The Shallow Water Table In A Mining Area: The Lubin-Glogow Copper Region, Southwestern Poland

NASA Astrophysics Data System (ADS)

Bochenska, T.; Limisiewicz, P.; Loprawski, L.

1995-03-01

In regions of intense mining, shortages of water are common. Increased water demand is normally associated with industry in mining areas, and mine unwatering has negative effects on the natural groundwater balance. The study area occupies 3,300 square kilometers within the copper mining region of Lubin-Glogow, southwestern Poland. Pumping of groundwater to drain mines has created a cone of depression that underlies 2,500 square kilometers. The lowering of potentiometric surfaces has occurred in deep aquifers, which are isolated from the surface by thick confining units (loams and clays). Changes of hydraulic head in the shallow aquifer have not previously been observed. In this study, the authors analyzed the water-table changes in the shallow aquifer. The statistical analysis of the water table was based on two sets of water-level measurements in about 1,200 farm wells during dry seasons. The first set was done in the fall of 1986, the second in the fall of 1991. In addition to these measurements, multi-seasonal observations were made by the mining survey in several tens of wells. During five years, the head declined an average of 0.4 meter. Locally, the lowering was as great as five meters. The regional decline of head resulted in a loss of water resources about 2×108 cubic meters. Regionally, this loss is not directly related to the dewatering of copper mines. Locally, however, mining activity strongly influences the water table. The general trend of the decline is probably an effect of decreasing precipitation.

Stormflow hydrochemistry of a river draining an abandoned metal mine: the Afon Twymyn, central Wales.

PubMed

Byrne, Patrick; Reid, Ian; Wood, Paul J

2013-03-01

Contaminated drainage from metal mines is a serious water-quality problem facing nations that exploit metal mineral resources. Measurements of river hydrochemistry during baseflow are common at mine sites, whilst detailed hydrochemical information regarding stormflow is limited and often confined to a single event. This study investigates the seasonal evolution of stormflow hydrochemistry at an abandoned metal mine in central Wales, UK, and the possible sources and mechanisms of metal release. Significant flushing of metals was observed during stormflow events, resulting in concentrations that severely exceeded water-quality guidelines. The relationship between metal concentrations and river discharge suggests dissolution of efflorescent metal sulphates on the surface of the mine spoil as the principal source of the contamination. High fluxes of Pb during stormflows are linked to extended periods of dry weather prior to storm events that produced water table drawdown and encouraged oxidation of Pb sulphide in the mine spoil. However, some Pb flushing also occurred following wet antecedent conditions. It is suggested that Fe oxide reduction in mine spoil and translatory flows involving metal-rich pore waters results in flushing during wetter periods. Detailed measurements of stormflow hydrochemistry at mine sites are essential for accurate forecasting of long-term trends in metals flux to understand metal sources and mechanisms of release, to assess potential risks to water quality and instream ecology, and to gauge the potential effectiveness of remediation. In order to protect riverine and riparian ecosystems, it is suggested that routine monitoring of stormflows becomes part of catchment management in mining-impacted regions.

Hydrologic characteristics of surface-mined land reclaimed by sludge irrigation, Fulton County, Illinois

USGS Publications Warehouse

Patterson, G.L.; Fuentes, R.F.; Toler, L.G.

1982-01-01

Analyses of water samples collected at four stream-monitoring stations, in an area surface mined for coal and being reclaimed by sludge irrigation, show the principal metals are sodium, calcium, and magnesium and principal non-metals are chloride, sulfate, and bicarbonate. Comparing yearly mean chemical concentrations shows no changing trends since reclamation began, nor are there differences between stations upstream and downstream from the site. Yearly suspended-sediment loads and discharge relations upstream and downstream from the site also show no differences. Discharge hydrographs of two streams draining the site show a delayed response to precipitation due to the storage capacity of several upstream strip-mine lakes. The water-table surface generally follows the irregular topography. Monthly water-level fluctuations were dependent on the surface material (mined or unmined) and proximity to surface discharge. The largest fluctuations were in unmined land away from discharge while the smallest were in mined land near discharge. The water table is closer to the surface in unmined land. Analyses of water samples from 70 wells within or adjacent to the reclamation site showed no differences in water quality which could be attributed to sludge or supernatant application. Samples from wells in mined land, however, had higher concentrations of dissolved sulfate, calcium, magnesium, chloride, iron, zinc, and manganese than samples from wells in unmined land. (USGS)

High contents of rare earth elements (REEs) in stream waters of a Cu-Pb-Zn mining area.

PubMed

Protano, G; Riccobono, F

2002-01-01

Stream waters draining an old mining area present very high rare earth element (REE) contents, reaching 928 microg/l as the maximum total value (sigmaREE). The middle rare earth elements (MREEs) are usually enriched with respect to both the light (LREEs) and heavy (HREEs) elements of this group, producing a characteristic "roof-shaped" pattern of the shale Post-Archean Australian Shales-normalized concentrations. At the Fenice Capanne Mine (FCM), the most important base metal mine of the study area, the REE source coincides with the mine tailings, mostly the oldest ones composed of iron-rich materials. The geochemical history of the REEs released into Noni stream from wastes in the FCM area is strictly determined by the pH, which controls the REE speciation and in-stream processes. The formation of Al-rich and mainly Fe-rich flocs effectively scavenges the REEs, which are readily and drastically removed from the solution when the pH approaches neutrality. Leaching experiments performed on flocs and waste materials demonstrate that Fe-oxides/oxyhydroxides play a key role in the release of lanthanide elements into stream waters. The origin of the "roof-shaped" REE distribution pattern as well as the peculiar geochemical behavior of some lanthanide elements in the aqueous system are discussed.

Distribution of biota in a stream polluted by acid mine-drainage

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

Warner, R.W.

1971-01-01

Acidic water draining from coal mines has severly restricted the diversity of biota inhabiting Roaring Creek, eastern West Virginia. Polluted reaches of the stream (median pH values ranging from 2.8 to 3.8) were inhabited by 3 to 12 genera of bottom-dwelling invertebrates and 10 to 19 species of periphytic algae. Invertebrates tolerant of the pollution included Sialis sp., chironomus plumosus and other Chironomidae, dytiscid beetles, and Ptilostomis sp. Predominant among the tolerant periphyton were Ulothrix tenerrima, Pinnularia termitina, Eunotia exigua, and Euglena mutabilis. Six other species of algae were tolerant of the acid mine-pollution, but were never numerous. Sections ofmore » Roaring Creek not severely polluted by acid drainage (pH medians of 4.5 or higher) supported diverse communities of 25 or more kinds of benthic animals and 27 or more species of periphytic algae. These stream reaches were inhibited by blackflies, crayfish, mayflies, stoneflies, and many species of caddisflies; these forms did not inhabit the more acidic stream reaches. Because of the complex and varying chemical composition of the acid mine-drainage, and also because of possible physical influences, measurements of pH values in the stream seemed to provide the most reliable, as well as unique, index of the effects of acid mine-drainage on aquatic life.« less

Approach for environmental baseline water sampling

USGS Publications Warehouse

Smith, K.S.

2011-01-01

Samples collected during the exploration phase of mining represent baseline conditions at the site. As such, they can be very important in forecasting potential environmental impacts should mining proceed, and can become measurements against which future changes are compared. Constituents in stream water draining mined and mineralized areas tend to be geochemically, spatially, and temporally variable, which presents challenges in collecting both exploration and baseline water-quality samples. Because short-term (daily) variations can complicate long-term trends, it is important to consider recent findings concerning geochemical variability of stream-water constituents at short-term timescales in designing sampling plans. Also, adequate water-quality information is key to forecasting potential ecological impacts from mining. Therefore, it is useful to collect baseline water samples adequate tor geochemical and toxicological modeling. This requires complete chemical analyses of dissolved constituents that include major and minor chemical elements as well as physicochemical properties (including pH, specific conductance, dissolved oxygen) and dissolved organic carbon. Applying chemical-equilibrium and appropriate toxicological models to water-quality information leads to an understanding of the speciation, transport, sequestration, bioavailability, and aquatic toxicity of potential contaminants. Insights gained from geochemical and toxicological modeling of water-quality data can be used to design appropriate mitigation and for economic planning for future mining activities.

Surface water monitoring in the mercury mining district of Asturias (Spain).

PubMed

Loredo, Jorge; Petit-Domínguez, María Dolores; Ordóñez, Almudena; Galán, María Pilar; Fernández-Martínez, Rodolfo; Alvarez, Rodrigo; Rucandio, María Isabel

2010-04-15

Systematic monitoring of surface waters in the area of abandoned mine sites constitutes an essential step in the characterisation of pollution from historic mine sites. The analytical data collected throughout a hydrologic period can be used for hydrological modelling and also to select appropriate preventive and/or corrective measures in order to avoid pollution of watercourses. Caudal River drains the main abandoned Hg mine sites (located in Mieres and Pola de Lena districts) in Central Asturias (NW Spain). This paper describes a systematic monitoring of physical and chemical parameters in eighteen selected sampling points within the Caudal River catchment. At each sampling station, water flow, pH, specific conductance, dissolved oxygen, salinity, temperature, redox potential and turbidity were controlled "in situ" and major and trace elements were analysed in the laboratory. In the Hg-mineralised areas, As is present in the form of As-rich pyrite, realgar and occasionally arsenopyrite. Mine drainage and leachates from spoil heaps exhibit in some cases acidic conditions and high As contents, and they are incorporated to Caudal River tributaries. Multivariate statistical analysis aids to the interpretation of the spatial and temporary variations found in the sampled areas, as part of a methodology applicable to different environmental and geological studies. 2009 Elsevier B.V. All rights reserved.

Hydrology and subsidence potential of proposed coal-lease tracts in Delta County, Colorado

USGS Publications Warehouse

Brooks, Tom

1983-01-01

Potential subsidence from underground coal mining and associated hydrologic impacts were investigated at two coal-lease tracts in Delta County, Colorado. Alteration of existing flow systems could affect water users in the surrounding area. The Mesaverde Formation transmits little ground water because of the neglibile transmissivity of the 1,300 feet of fine-grained sandstone, coal , and shale comprising the formation. The transmissivities of coal beds within the lower Mesaverde Formation ranged from 1.5 to 16.7 feet squared per day, and the transmissivity of the upper Mesaverde Formation, based on a single test, was 0.33 foot squared per day. Transmissivities of the alluvium ranged from 108 to 230 feet squared per day. The transmissivity of unconsolidated Quaternary deposits, determined from an aquifer test, was about 1,900 feet squared per day. Mining beneath Stevens Gulch and East Roatcap Creek could produce surface expressions of subsidence. Subsidence fractures could partly drain alluvial valley aquifers or streamflow in these mines. (USGS)

Data on Streamflow and Quality of Water and Bottom Sediment in and near Humboldt Wildlife Management Area, Churchill and Pershing Counties, Nevada, 1998-2000

USGS Publications Warehouse

Paul, Angela P.; Thodal, Carl E.

2003-01-01

This study was initiated to expand upon previous findings that indicated concentrations of dissolved solids, arsenic, boron, mercury, molybdenum, selenium, and uranium were either above geochemical background concentrations or were approaching or exceeding ecological criteria in the lower Humboldt River system. Data were collected from May 1998 to September 2000 to further characterize streamflow and surface-water and bottom-sediment quality in the lower Humboldt River, selected agricultural drains, Upper Humboldt Lake, and Lower Humboldt Drain (ephemeral outflow from Humboldt Sink). During this study, flow in the lower Humboldt River was either at or above average. Flows in Army and Toulon Drains generally were higher than reported in previous investigations. An unnamed agricultural drain contributed a small amount to the flow measured in Army Drain. In general, measured concentrations of sodium, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium were higher in water from agricultural drains than in Humboldt River water during this study. Mercury concentrations in water samples collected during the study period typically were below the laboratory reporting level. However, low-level mercury analyses showed that samples collected in August 1999 from Army Drain had higher mercury concentrations than those collected from the river or Toulon Drain or the Lower Humboldt Drain. Ecological criteria and effect concentrations for sodium, chloride, dissolved solids, arsenic, boron, mercury, and molybdenum were exceeded in some water samples collected as part of this study. Although water samples from the agricultural drains typically contained higher concentrations of sodium, chloride, dissolved solids, arsenic, boron, and uranium, greater instantaneous loads of these constituents were carried in the river near Lovelock than in agricultural drains during periods of high flow or non-irrigation. During this study, the high flows in the lower Humboldt River produced the maximum instantaneous loads of sodium, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium at all river-sampling sites, except molybdenum near Imlay. Nevada Division of Environmental Protection monitoring reports on mine-dewatering discharge for permitted releases of treated effluent to the surface waters of the Humboldt River and its tributaries were reviewed for reported discharges and trace-element concentrations from June 1998 to September 1999. These data were compared with similar information for the river near Imlay. In all bottom sediments collected for this study, arsenic concentrations exceeded the Canadian Freshwater Interim Sediment-Quality Guideline for the protection of aquatic life and probable-effect level (concentration). Sediments collected near Imlay, Rye Patch Reservoir, Lovelock, and from Toulon Drain and Army Drain were found to contain cadmium and chromium concentrations that exceeded Canadian criteria. Chromium concentrations in sediments collected from these sites also exceeded the consensus-based threshold-effect concentration. The Canadian criterion for sediment copper concentration was exceeded in sediments collected from the Humboldt River near Lovelock and from Toulon, Army, and the unnamed agricultural drains. Mercury in sediments collected near Imlay and from Toulon Drain in August 1999 exceeded the U.S. Department of the Interior sediment probable-effect level. Nickel concentrations in sediments collected during this study were above the consensus-based threshold-effect concentration. All other river and drain sediments had constituent concentrations below protective criteria and toxicity thresholds. In Upper Humboldt Lake, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium concentrations in surface-water samples collected near the mouth of the Humboldt River generally were higher than in samples collected near the mouth of Army Drain. Ecological criteria or effect con

Island of Luzon, Philippines

NASA Technical Reports Server (NTRS)

1990-01-01

In this north to south view of the Island of Luzon, Philippines (13.0N, 120.0E), the prominent Cordillera Central mountain range where gold, copper and silver are mined. The several large rivers that drain this region normally carry a heavy silt load to the sea but the absence of sediment plumes in this view is evidence of hot dry weather and lack of recent rains. Manila, the capital city is just visible at the south end of the island.

Control of groundwater in surface mining

NASA Astrophysics Data System (ADS)

Brawner, C. O.

1982-03-01

The presence of groundwater in surface mining operations often creates serious problems. The most important is generally a reduction in stability of the pit slopes. This is caused by pore water pressures and hydrodynamic shock due to blasting which reduce the shear strength and seepage pressures, water in tension cracks and increased unit weight which increase the shear stress. Groundwater and seepage also increase the cost of pit drainage, shipping, drilling and blasting, tyre wear and equipment maintenance. Surface erosion may also be increased and, in northern climates, ice flows on the slopes may occur. Procedures have been developed in the field of soil mechanics and engineering of dams to obtain quantitative data on pore water pressures and rock permeability, to evaluate the influence of pore water and seepage pressures on stability and to estimate the magnitude of ground-water flow. Based on field investigations, a design can be prepared for the control of groundwater in the slope and in the pit. Methods of control include the use of horizontal drains, blasted toe drains, construction of adits or drainage tunnels and pumping from wells in or outside of the pit. Recent research indicates that subsurface drainage can be augmented by applying a vacuum or by selective blasting. Instrumentation should be installed to monitor the groundwater changes created by drainage. Typical case histories are described that indicate the approach used to evaluate groundwater conditions.

Overview of mine drainage geochemistry at historical mines, Humboldt River basin and adjacent mining areas, Nevada. Chapter E.

USGS Publications Warehouse

Nash, J. Thomas; Stillings, Lisa L.

2004-01-01

Reconnaissance hydrogeochemical studies of the Humboldt River basin and adjacent areas of northern Nevada have identified local sources of acidic waters generated by historical mine workings and mine waste. The mine-related acidic waters are rare and generally flow less than a kilometer before being neutralized by natural processes. Where waters have a pH of less than about 3, particularly in the presence of sulfide minerals, the waters take on high to extremely high concentrations of many potentially toxic metals. The processes that create these acidic, metal-rich waters in Nevada are the same as for other parts of the world, but the scale of transport and the fate of metals are much more localized because of the ubiquitous presence of caliche soils. Acid mine drainage is rare in historical mining districts of northern Nevada, and the volume of drainage rarely exceeds about 20 gpm. My findings are in close agreement with those of Price and others (1995) who estimated that less than 0.05 percent of inactive and abandoned mines in Nevada are likely to be a concern for acid mine drainage. Most historical mining districts have no draining mines. Only in two districts (Hilltop and National) does water affected by mining flow into streams of significant size and length (more than 8 km). Water quality in even the worst cases is naturally attenuated to meet water-quality standards within about 1 km of the source. Only a few historical mines release acidic water with elevated metal concentrations to small streams that reach the Humboldt River, and these contaminants and are not detectable in the Humboldt. These reconnaissance studies offer encouraging evidence that abandoned mines in Nevada create only minimal and local water-quality problems. Natural attenuation processes are sufficient to compensate for these relatively small sources of contamination. These results may provide useful analogs for future mining in the Humboldt River basin, but attention must be given to matters of scale: larger volumes of waste and larger volumes of water could easily overwhelm the delicate balance of natural attenuation described here.

Recent Developments for Remediating Acidic Mine Waters Using Sulfidogenic Bacteria

PubMed Central

Bitencourt, José A. P.; Sahoo, Prafulla K.; Alves, Joner Oliveira; Siqueira, José O.

2017-01-01

Acidic mine drainage (AMD) is regarded as a pollutant and considered as potential source of valuable metals. With diminishing metal resources and ever-increasing demand on industry, recovering AMD metals is a sustainable initiative, despite facing major challenges. AMD refers to effluents draining from abandoned mines and mine wastes usually highly acidic that contain a variety of dissolved metals (Fe, Mn, Cu, Ni, and Zn) in much greater concentration than what is found in natural water bodies. There are numerous remediation treatments including chemical (lime treatment) or biological methods (aerobic wetlands and compost bioreactors) used for metal precipitation and removal from AMD. However, controlled biomineralization and selective recovering of metals using sulfidogenic bacteria are advantageous, reducing costs and environmental risks of sludge disposal. The increased understanding of the microbiology of acid-tolerant sulfidogenic bacteria will lead to the development of novel approaches to AMD treatment. We present and discuss several important recent approaches using low sulfidogenic bioreactors to both remediate and selectively recover metal sulfides from AMD. This work also highlights the efficiency and drawbacks of these types of treatments for metal recovery and points to future research for enhancing the use of novel acidophilic and acid-tolerant sulfidogenic microorganisms in AMD treatment. PMID:29119111

Chemical quality, benthic organisms, and sedimentation in streams draining coal-mined lands in Raccoon Creek basin, Ohio, July 1984 through September 1986

USGS Publications Warehouse

Wilson, K.S.

1988-01-01

The Ohio Department of Natural Resources, Division of Reclamation, plans widespread reclamation of abandoned coal mines in the Raccoon Creek basin in southeastern Ohio. Throughout Raccoon Creek basin, chemical, biological, and suspended-sediment data were collected from July 1984 through September 1986. Chemical and biological data collected at 17 sites indicate that the East Branch, Brushy Creek, Hewett Fork, and Little Raccoon Creek subbasins, including Flint Run, are affected by drainage from abandoned coal mines. In these basins, median pH values ranged from 2.6 to 5.1, median acidity values ranged from 20 to 1,040 mg/L (milligrams per liter) as CaCo3, and median alkalinity values ranged from 0 to 4 mg/L as CaCo3. Biological data indicate that these basins do not support diverse populations because of degraded water systems. Suspended-sediment yields of 70.7 tons per square mile per year at the headwaters of Raccoon Creek and 54.5 tons per square mile per year near the month of Raccoon Creek indicate that cumulative sedimentation from erosion of abandoned-mine lands is not excessive in the basin.

Resistivity profiling to locate an infiltration area and the possible recovery of the dried Andara lake (Picos de Europa National Park, Spain)

NASA Astrophysics Data System (ADS)

Gallastegui, Jorge; Olona, Javier; Farias, Pedro; González-Cortina, Juan Manuel; Fernández-Viejo, Gabriela; López, Carlos; Cadenas, Patricia

2013-04-01

The Ándara Lake constituted the third mass of water by extension (approximately 19000 m2) within the calcareous Picos de Europa Massif in NW Spain, but only a small pond remains today (about 1250 m2). The lake developed in a former glacial valley and its sudden draining occurred in the second decade of the 20th century, during the development of underground Pb-Zn mining, between 1889 and 1929, in the vicinity. Old mining maps show that there were shallow galleries active below the bottom of the ancient lake. The present study was requested by the Picos de Europa National Park Administration (Spanish Ministry of Environment) with the purpose of: i) localizing the areas of water infiltration and ii) establishing the cause of the draining, specially its possible relation with the mining activity in the surroundings. With this aim a geological study of the substrate of the lake was made, followed by a series of electrical resistivity profiles. Three resistivity parallel profiles were recorded along the axis of the dried lake on the 29th July. Each profile included 56 electrodes with 5 m spacing for a total profile length of 275 m. Data was recorded in both dipole-dipole and Schlumberger array configuration. The western profile had been recorded earlier in the summer (30th June) and was also repeated towards the end of the season (3rd September) in order to evaluate the evolution of the infiltrations. The results showed two areas of infiltration to the NE and SW of the present-day pond. Both of them cut across the underlying carboniferous limestone. However. the southwestern anomaly does not reach the surface and may be related with water flowing in karstic conduits in the limestone. The northeastern one reached the surface and the anomaly decreased as the pond dried during the summer allowing us to interpret it as the main area of infiltration. This area coincides with the intersection of two seams exploited both on the surface and by underground mining. This corroborates the relationship between the water disappearance and the mining activities, which is an indispensable condition for the National Park management to consider taking any future actions aimed to a possible recovery of the original water mass.

Water quality of streams draining abandoned and reclaimed mined lands in the Kantishna Hills area, Denali National Park and Preserve, Alaska, 2008–11

USGS Publications Warehouse

Brabets, Timothy P.; Ourso, Robert T.

2013-01-01

The Kantishna Hills are an area of low elevation mountains in the northwest part of Denali National Park and Preserve, Alaska. Streams draining the Kantishna Hills are clearwater streams that support several species of fish and are derived from rain, snowmelt, and subsurface aquifers. However, the water quality of many of these streams has been degraded by mining. Past mining practices generated acid mine drainage and excessive sediment loads that affected water quality and aquatic habitat. Because recovery through natural processes is limited owing to a short growing season, several reclamation projects have been implemented on several streams in the Kantishna Hills region. To assess the current water quality of streams in the Kantishna Hills area and to determine if reclamation efforts have improved water quality, a cooperative study between the U.S. Geological Survey and the National Park Service was undertaken during 2008-11. High levels of turbidity, an indicator of high concentrations of suspended sediment, were documented in water-quality data collected in the mid-1980s when mining was active. Mining ceased in 1985 and water-quality data collected during this study indicate that levels of turbidity have declined significantly. Turbidity levels generally were less than 2 Formazin Nephelometric Units and suspended sediment concentrations generally were less than 1 milligram per liter during the current study. Daily turbidity data at Rock Creek, an unmined stream, and at Caribou Creek, a mined stream, documented nearly identical patterns of turbidity in 2009, indicating that reclamation as well as natural revegetation in mined streams has improved water quality. Specific conductance and concentrations of dissolved solids and major ions were highest from streams that had been mined. Most of these streams flow into Moose Creek, which functions as an integrator stream, and dilutes the specific conductance and ion concentrations. Calcium and magnesium are the dominant cations, and bicarbonate and sulfate are the dominant anions. Water samples indicate that the water from Rock Creek, Moose Creek, Slate Creek, and Eldorado Creek is a calcium bicarbonate-type water. The remaining sites are a calcium sulfate type water. U.S. Environmental Protection Agency guidelines for arsenic and antimony in drinking water were exceeded in water at Slate Creek and Eureka Creek. Concentrations of arsenic, cadmium, chromium, copper, lead, nickel, and zinc in streambed sediments at many sites exceed sediment quality guideline thresholds that could be toxic to aquatic life. However, assessment of these concentrations, along with the level of organic carbon detected in the sediment, indicate that only concentrations of arsenic and chromium may be toxic to aquatic life at many sites. In 2008 and 2009, 104 macroinvertebrate taxa and 164 algae taxa were identified from samples collected from seven sites. Of the macroinvertebrates, 86 percent were insects and most of the algae consisted of diatoms. Based on the National Community Index, Rock Creek, a reference site, and Caribou Creek, and a mined stream that had undergone some reclamation, exhibited the best overall stream conditions; whereas Slate Creek and Friday Creek, two small streams that were mined extensively, exhibited the worst stream conditions. A non-metric multi-dimensional scaling analysis of the macroinvertebrate and algae data showed a distinct grouping between the 2008 and 2009 samples, likely because of differences between a wet, cool summer in 2008 and a dry, warm summer in 2009.

Questa baseline and pre-mining ground-water quality investigation. 23. Quantification of mass loading from mined and unmined areas along the Red River, New Mexico

USGS Publications Warehouse

Kimball, Briant A.; Nordstrom, D. Kirk; Runkel, Robert L.; Vincent, Kirk R.; Verplanck, Phillip L.

2006-01-01

Along the course of the Red River, between the town of Red River, New Mexico, and the U.S. Geological Survey streamflow-gaging station near Questa, New Mexico, there are several catchments that contain hydrothermally altered bedrock. Some of these alteration zones have been mined and others have not, presenting an opportunity to evaluate differences that may exist in the mass loading of metals from mined and unmined sections. Such differences may help to define pre-mining conditions. Spatially detailed chemical sampling at stream and inflow sites occurred during low-flow conditions in 2001 and 2002, and during the synoptic sampling, stream discharge was calculated by tracer dilution. Discharge from most catchments, particularly those with alteration scars, occurred as ground water in large debris fans, which generally traveled downstream in an alluvial aquifer until geomorphic constraints caused it to discharge at several locations along the study reach. Locations of discharge zones were indicated by the occurrence of numerous inflows as seeps and springs. Inflows were classified into four groups, based on differences in chemical character, which ranged from near-neutral water showing no influence of mining or alteration weathering to acidic water with high concentrations of metals and sulfate. Acidic, metal-rich inflows occurred from mined and unmined areas, but the most-acidic inflow water that had the highest concentrations of metals and sulfate only occurred downstream from the mine. Locations of ground-water inflow also corresponded to substantial changes in stream chemistry and mass loading of metals and sulfate. The greatest loading occurred in the Cabin Springs, Thunder Bridge, and Capulin Canyon sections, which all occur downstream from the mine. A distinct chemical character and substantially greater loading in water downstream from the mine suggest that there could be impacts from mining that can be distinguished from the water draining from unmined areas.

Abandoned mine drainage in the Swatara Creek Basin, southern anthracite coalfield, Pennsylvania, USA: 2. performance of treatment systems

USGS Publications Warehouse

Cravotta, Charles A.

2010-01-01

A variety of passive and semi-passive treatment systems were constructed by state and local agencies to neutralize acidic mine drainage (AMD) and reduce the transport of dissolved metals in the upper Swatara Creek Basin in the Southern Anthracite Coalfield in eastern Pennsylvania. To evaluate the effectiveness of selected treatment systems installed during 1995–2001, the US Geological Survey collected water-quality data at upstream and downstream locations relative to each system eight or more times annually for a minimum of 3 years at each site during 1996–2007. Performance was normalized among treatment types by dividing the acid load removed by the size of the treatment system. For the limestone sand, open limestone channel, oxic limestone drain, anoxic limestone drain (ALD), and limestone diversion well treatment systems, the size was indicated by the total mass of limestone; for the aerobic wetland systems, the size was indicated by the total surface area of ponds and wetlands. Additionally, the approximate cost per tonne of acid treated over an assumed service life of 20 years was computed. On the basis of these performance metrics, the limestone sand, ALD, oxic limestone drain, and limestone diversion wells had similar ranges of acid-removal efficiency and cost efficiency. However, the open limestone channel had lower removal efficiency and higher cost per ton of acid treated. The wetlands effectively attenuated metals transport but were relatively expensive considering metrics that evaluated acid removal and cost efficiency. Although the water-quality data indicated that all treatments reduced the acidity load from AMD, the ALD was most effective at producing near-neutral pH and attenuating acidity and dissolved metals. The diversion wells were effective at removing acidity and increasing pH of downstream water and exhibited unique potential to treat moderate to high flows associated with storm flow conditions.

Water quality and discharge of streams in the Lehigh River Basin, Pennsylvania

USGS Publications Warehouse

McCarren, Edward F.; Keighton, Walter B.

1969-01-01

The Lehigh River, 100 miles long, is the second largest tributary to the Delaware River. It drains 1,364 square miles in four physiographic provinces. The Lehigh River basin includes mountainous and forested areas, broad agricultural valleys and areas of urban and industrial development. In the headwaters the water is of good quality and has a low concentration of solutes. Downstream, some tributaries receive coal-mine drainage and become acidic; others drain areas underlain by limestone and acquire alkaline characteristics. The alkaline streams neutralize and dilute the acid mine water where they mix. The dissolved-oxygen content of river water, which is high in the upper reaches of the stream, is reduced in the lower reaches because of lower turbulence, higher temperature, and the respiration of organisms. The Lehigh is used for public supply, recreation, waterpower, irrigation, and mining and other industrial purposes. Because the river is shallow in its upper reaches, most of the water comes in contact with the atmosphere as it churns over rocks and around islets and large boulders. Aeration of the water is rapid. When water that was low in dissolved-oxygen concentration was released from the lower strata of the Francis E. Walter Reservoir in June 1966, it quickly became aerated in the Lehigh River, and for 40 miles downstream from the dam the water was nearly saturated with oxygen. Most of the river water requires only moderate treatment for industrial use and public distribution throughout the Lehigh River valley. At times, however, some segments of the main river and its tributaries transport industrial wastes and acid coal-mine drainage. Usually the relatively high concentrations of solutes in water and the ensuing damage caused to quality by such waste discharges are more extensive and prolonged during droughts and other periods of low streamflow. For many years the Lehigh River flow has been continuously measured and its water chemically analyzed. Since May 1966 an instrument installed by the U.S. Geological Survey at Easton, Pa., has continuously recorded such water-quality parameters as specific conductance, temperature, and dissolved oxygen content.

Platinum group elements in stream sediments of mining zones: The Hex River (Bushveld Igneous Complex, South Africa)

NASA Astrophysics Data System (ADS)

Almécija, Clara; Cobelo-García, Antonio; Wepener, Victor; Prego, Ricardo

2017-05-01

Assessment of the environmental impact of platinum group elements (PGE) and other trace elements from mining activities is essential to prevent potential environmental risks. This study evaluates the concentrations of PGE in stream sediments of the Hex River, which drains the mining area of the Bushveld Igneous Complex (South Africa), at four sampling points. Major, minor and trace elements (Fe, Ca, Al, Mg, Mn, V, Cr, Zn, Cu, As, Co, Ni, Cd, and Pb) were analyzed by FAAS and ETAAS in suspended particulate matter and different sediment fractions (<63, 63-500 and 500-2000 μm), and Pt, Pd, Rh, and Ir were measured by ICP-MS after removal of interfering elements (cation exchange resin 50W-DOWEX-X8). Procedures were blank-corrected and accuracy checked using reference materials. Nickel, Cr, Pt, Pd, Rh and Ir show concentrations 3-, 13- 18-, 28-, 48- and 44- fold the typical upper continental crust levels, respectively, although lower than concentrations reported for the parent rocks. The highest concentrations were observed closer to the mining area, decreasing with distance and in the <63 μm fraction, probably derived from atmospheric deposition and surface runoff of PGE-rich particles released from mining activities. Thus, mining activities are causing some disturbance of the surface PGE geochemical cycle, increasing the presence of PGE in the fine fraction of river sediments. We propose that indicators such as airborne particulate matter, and soil and river sediment quality, should be added to the protocols for evaluating the sustainability of mining activities.

Environmental consequences of the Retsof Salt Mine roof collapse

USGS Publications Warehouse

Yager, Richard M.

2013-01-01

In 1994, the largest salt mine in North America, which had been in operation for more than 100 years, catastrophically flooded when the mine ceiling collapsed. In addition to causing the loss of the mine and the mineral resources it provided, this event formed sinkholes, caused widespread subsidence to land, caused structures to crack and subside, and changed stream flow and erosion patterns. Subsequent flooding of the mine drained overlying aquifers, changed the groundwater salinity distribution (rendering domestic wells unusable), and allowed locally present natural gas to enter dwellings through water wells. Investigations including exploratory drilling, hydrologic and water-quality monitoring, geologic and geophysical studies, and numerical simulation of groundwater flow, salinity, and subsidence have been effective tools in understanding the environmental consequences of the mine collapse and informing decisions about management of those consequences for the future. Salt mines are generally dry, but are susceptible to leaks and can become flooded if groundwater from overlying aquifers or surface water finds a way downward into the mined cavity through hundreds of feet of rock. With its potential to flood the entire mine cavity, groundwater is a constant source of concern for mine operators. The problem is compounded by the viscous nature of salt and the fact that salt mines commonly lie beneath water-bearing aquifers. Salt (for example halite or potash) deforms and “creeps” into the mined openings over time spans that range from years to centuries. This movement of salt can destabilize the overlying rock layers and lead to their eventual sagging and collapse, creating permeable pathways for leakage of water and depressions or openings at land surface, such as sinkholes. Salt is also highly soluble in water; therefore, whenever water begins to flow into a salt mine, the channels through which it flows increase in diameter as the surrounding salt dissolves. Some mines leak at a slow rate for decades before a section of rock gives way, allowing what initially was a trickle of water to suddenly become a cascade and finally a torrent. Other mines become flooded and are destroyed when an errant drill hole punctures the mine ceiling, allowing water from overlying sources to flow into the mine. Either scenario can cause catastrophic flooding and permanent loss of the mine. Occasionally, a mine that has remained dry for a century will undergo a roof collapse that results in flooding.

Method of gas emission control for safe working of flat gassy coal seams

NASA Astrophysics Data System (ADS)

Vinogradov, E. A.; Yaroshenko, V. V.; Kislicyn, M. S.

2017-10-01

The main problems at intensive flat gassy coal seam longwall mining are considered. For example, mine Kotinskaja JSC “SUEK-Kuzbass” shows that when conducting the work on the gassy coal seams, methane emission control by means of ventilation, degassing and insulated drain of methane-air mixture is not effective and stable enough. It is not always possible to remove the coal production restrictions by the gas factor, which leads to financial losses because of incomplete using of longwall equipment and the reduction of the technical and economic indicators of mining. To solve the problems, the authors used a complex method that includes the compilation and analysis of the theory and practice of intensive flat gassy coal seam longwall mining. Based on the results of field and numerical researches, the effect of parameters of technological schemes on efficiency of methane emission control on longwall panels, the non-linear dependence of the permissible according to gas factor longwall productivity on parameters of technological schemes, ventilation and degassing during intensive mining flat gassy coal seams was established. The number of recommendations on the choice of the location and the size of the intermediate section of coal heading to control gassing in the mining extracted area, and guidelines for choosing the parameters of ventilation of extracted area with the help of two air supply entries and removal of isolated methane-air mixture are presented in the paper. The technological scheme, using intermediate entry for fresh air intake, ensuring effective management gassing and allowing one to refuse from drilling wells from the surface to the mined-out space for mining gas-bearing coal seams, was developed.

The National Shipbuilding Research Program. Survey of Air and Water Quality Pollution Prevention and Control Technology Used in Shipyards and Similar Industries

DTIC Science & Technology

1998-01-09

vehicle washing 3. TSP and citric acid for bilge cleaning 1. no capture and filtration of weld fumes 8 1. black beauty abrasives 2...treatment 1. not treated N/A 12 N/A 1. treated on-site. with gravity oil water separator, acid cracking of the emulsion layer and parallel...less energy-intensive treatment technologies such as constructed wetlands for sewage treatment and anoxic limestone drains for acid mine drainage

Mercury speciation in the Mt. Amiata mining district (Italy): interplay between urban activities and mercury contamination

USGS Publications Warehouse

Rimondi, Valentina; Bardelli, Fabrizio; Benvenuti, Marco; Costagliola, Pilario; Gray, John E.; Lattanzi, Pierfranco

2014-01-01

A fundamental step to evaluate the biogeochemical and eco-toxicological significance of Hg dispersion in the environment is to determine speciation of Hg in solid matrices. In this study, several analytical techniques such as scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), sequential chemical extractions (SCEs), and X-ray absorption spectroscopy (XANES) were used to identify Hg compounds and Hg speciation in samples collected from the Mt. Amiata Hg mining district, southern Tuscany, Italy. Different geological materials, such as mine waste calcine (retorted ore), soil, stream sediment, and stream water suspended particulate matter were analyzed. Results show that the samples were generally composed of highly insoluble Hg compounds such as sulphides (HgS, cinnabar and metacinnabar), and more soluble Hg halides such as those associated with the mosesite group. Other moderately soluble Hg compounds, HgCl2, HgO and Hg0, were also identified in stream sediments draining the mining area. The presence of these minerals suggests active and continuous runoff of soluble Hg compounds from calcines, where such Hg compounds form during retorting, or later in secondary processes. Specifically, we suggest that, due to the proximity of Hg mines to the urban center of Abbadia San Salvatore, the influence of other anthropogenic activities was a key factor for Hg speciation, resulting in the formation of unusual Hg-minerals such as mosesite.

Earth Observations taken by the Expedition 13 crew

NASA Image and Video Library

2006-08-02

ISS013-E-63766 (2 Aug. 2006) --- Berkeley Pit and Butte, Montana are featured in this image photographed by an Expedition 13 crewmember on the International Space Station. The city of Butte, Montana has long been a center of mining activity. Underground mining of copper began in Butte in the 1870s, and by 1901 underground workings had extended to the groundwater table. Thus began the creation of an intricate complex of underground drains and pumps to lower the groundwater level and continue the extraction of copper. Water extracted from the mines was so rich in dissolved copper sulfate that it was also "mined" (by chemical precipitation) for the copper it contained. In 1955, the Anaconda Copper Mining Company began open-pit mining for copper in what is now know as the Berkeley Pit (dark oblong area in center). The mine took advantage of the existing subterranean drainage and pump network to lower groundwater until 1982, when the new owner ARCO suspended operations at the mine. The groundwater level swiftly rose, and today water in the Pit is more than 900 feet deep. Many features of the mine workings are visible in this image such as the many terraced levels and access roadways of the open mine pits (gray and tan sculptured surfaces). A large gray tailings pile of waste rock and an adjacent tailings pond are visible to the north of the Berkeley Pit. Color changes in the tailings pond are due primarily to changing water depth. The Berkeley Pit is listed as a federal Superfund site due to its highly acidic water, which contains high concentrations of metals such as copper and zinc. The Berkeley Pit receives groundwater flowing through the surrounding bedrock and acts as a "terminal pit" or sink for these heavy metal-laden waters. Ongoing efforts include regulation of water flow into the pit to reduce filling of the Pit and potential release of contaminated water into local aquifers or surface streams.

Hydrology of the North Fork of the Right Fork of Miller Creek, Carbon County, Utah, before, during, and after underground coal mining

USGS Publications Warehouse

Slaughter, C.B.; Freethey, G.W.; Spangler, L.E.

1995-01-01

From 1988-92 the U.S. Geological Survey, in cooperation with the Utah Division of Oil, Gas, and Mining, studied the effects of underground coal mining and the resulting subsidence on the hydrologic system near the North Fork of the Right Fork of Miller Creek, Carbon County, Utah. The subsidence caused open fractures at land surface, debris slides, and rockfalls in the canyon above the mined area. Land surface subsided and moved several feet horizontally. The perennial stream and a tributary upstream from the mined area were diverted below the ground by surface fractures where the overburden thickness above the Wattis coal seam is 300 to 500 feet. The reach downstream was dry but flow resumed where the channel traversed the Star Point Sandstone, which forms the aquifer below the coal seams where ground-water discharge provides new base flow. Concentrations of dissolved constituents in the stream water sampled just downstream from the mined area increased from about 300 mg/L (milligrams per liter) to more than 1,500 mg/L, and the water changed from primarily a magnesium calcium bicarbonate to primarily a magnesium sulfate type. Monitored water levels in two wells completed in the perched aquifer(s) above the mine indicate that fractures from subsidence- related deformation drained the perched aquifer in the Blackhawk Formation. The deformation also could have contributed to the decrease in discharge of three springs above the mined area, but discharge from other springs in the area did not change ubstantially; thus, the relation between subsidence and spring discharge, if any, is not clear. No significant changes in the chemical character of water discharging from springs were detected, but the dissolved-solids concentration in water collected from a perched sandstone aquifer overlying the mined coal seams increased during mining activity.

Size and performance of anoxic limestone drains to neutralize acdic mine drainagei

USGS Publications Warehouse

Cravotta, C.A.

2003-01-01

Acidic mine drainage (AMD) can be neutralized effectively in underground, anoxic limestone drains (ALDs). Owing to reaction between the AMD and limestone (CaCO3), the pH and concentrations of alkalinity and calcium increase asymptotically with detention time in the ALD, while concentrations of sulfate, ferrous iron, and manganese typically are unaffected. This paper introduces a method to predict the alkalinity produced within an ALD and to estimate the mass of limestone required for its construction on the basis of data from short-term, closed-container (cubitainer) tests. The cubitainer tests, which used an initial mass of 4 kg crushed limestone completely inundated with 2.8 L AMD, were conducted for 11 to 16 d and provided estimates for the initial and maximum alkalinities and corresponding rates of alkalinity production and limestone dissolution. Long-term (5-11 yr) data for alkalinity and CaCO3 flux at the Howe Bridge, Morrison, and Buck Mountain ALDs in Pennsylvania, USA, indicate that rates of alkalinity production and limestone dissolution under field conditions were comparable with those in cubitainers filled with limestone and AMD from each site. The alkalinity of effluent and intermediate samples along the flow path through the ALDs and long-term trends in the residual mass of limestone and the effluent alkalinity were estimated as a function of the computed detention time within the ALD and second-order dissolution rate models for cubitainer tests. Thus, cubitainer tests can be a useful tool for designing ALDs and predicting their performance.

Occurrence, distribution, and volume of metals-contaminated sediment of selected streams draining the Tri-State Mining District, Missouri, Oklahoma, and Kansas, 2011–12

USGS Publications Warehouse

Smith, D. Charlie

2016-12-14

Lead and zinc were mined in the Tri-State Mining District (TSMD) of southwest Missouri, northeast Oklahoma, and southeast Kansas for more than 100 years. The effects of mining on the landscape are still evident, nearly 50 years after the last mine ceased operation. The legacies of mining are the mine waste and discharge of groundwater from underground mines. The mine-waste piles and underground mines are continuous sources of trace metals (primarily lead, zinc, and cadmium) to the streams that drain the TSMD. Many previous studies characterized the horizontal extent of mine-waste contamination in streams but little information exists on the depth of mine-waste contamination in these streams. Characterizing the vertical extent of contamination is difficult because of the large amount of coarse-grained material, ranging from coarse gravel to boulders, within channel sediment. The U.S. Geological Survey, in cooperation with U.S. Fish and Wildlife service, collected channel-sediment samples at depth for subsequent analyses that would allow attainment of the following goals: (1) determination of the relation between concentration and depth for lead, zinc and cadmium in channel sediments and flood-plain sediments, and (2) determination of the volume of gravel-bar sediment from the surface to the maximum depth with concentrations of these metals that exceeded sediment-quality guidelines. For the purpose of this report, volume of gravel-bar sediment is considered to be distributed in two forms, gravel bars and the wetted channel, and this study focused on gravel bars. Concentrations of lead, zinc, and cadmium in samples were compared to the consensus probable effects concentration (CPEC) and Tri-State Mining District specific probable effects concentration (TPEC) sediment-quality guidelines.During the study, more than 700 sediment samples were collected from borings at multiple sites, including gravel bars and flood plains, along Center Creek, Turkey Creek, Shoal Creek, Tar Creek, and Spring River in order to characterize the vertical extent of mine waste in select streams in the TSMD. The largest concentrations of lead, zinc, and cadmium in gravel bar-sediment samples generally were detected in Turkey Creek and Tar Creek and the smallest concentrations were detected in Shoal Creek followed by the Spring River. Gravel bar-sediment samples from Turkey Creek exceeded the CPEC for cadmium (minimum of 70 percent of samples), lead (94 percent), and zinc (99 percent) at a slightly higher frequency than similar samples from Tar Creek (69 percent, 88 percent, and 96 percent, respectively). Gravel bar-sediment samples from Turkey Creek also contained the largest concentrations of cadmium (174 milligrams per kilogram [mg/kg]) and lead (7,520 mg/kg) detected; however, the largest zinc concentration (46,600 mg/kg) was detected in a gravel bar-sediment sample from Tar Creek. In contrast, none of the 65 gravel bar-sediment samples from Shoal Creek contained cadmium above the x-ray fluorescence reporting level of 12 mg/kg, and lead and zinc exceeded the CPEC in only 12 percent and 74 percent of samples, respectively. In most cases, concentrations of lead and zinc above the CPEC or TPEC were present at the maximum depth of boring, which indicated that nearly the entire thickness of sediment in the stream has been contaminated by mine wastes. Approximately 284,000 cubic yards of channel sediment from land surface to the maximum depth that exceeded the CPEC and approximately 236,000 cubic yards of channel sediment from land surface to the maximum depth that exceeded the TPEC were estimated along 37.6 of the 55.1 miles of Center Creek, Turkey Creek, Shoal Creek, and Tar Creek examined in this study. Mine-waste contamination reported along additional reaches of these streams is beyond the scope of this study. Flood-plain cores collected in the TSMD generally only had exceedances of the CPEC and TPEC for lead and zinc in the top 1 or 2 feet of soil with a few exceptions, such as cores in low areas near the stream or cores in areas disturbed by past mining.

Deep Impact: Effects of Mountaintop Mining on Surface Topography, Bedrock Structure, and Downstream Waters.

PubMed

Ross, Matthew R V; McGlynn, Brian L; Bernhardt, Emily S

2016-02-16

Land use impacts are commonly quantified and compared using 2D maps, limiting the scale of their reported impacts to surface area estimates. Yet, nearly all land use involves disturbances below the land surface. Incorporating this third dimension into our estimates of land use impact is especially important when examining the impacts of mining. Mountaintop mining is the most common form of coal mining in the Central Appalachian ecoregion. Previous estimates suggest that active, reclaimed, or abandoned mountaintop mines cover ∼7% of Central Appalachia. While this is double the areal extent of development in the ecoregion (estimated to occupy <3% of the land area), the impacts are far more extensive than areal estimates alone can convey as the impacts of mines extend 10s to 100s of meters below the current land surface. Here, we provide the first estimates for the total volumetric and topographic disturbance associated with mining in an 11 500 km(2) region of southern West Virginia. We find that the cutting of ridges and filling of valleys has lowered the median slope of mined landscapes in the region by nearly 10 degrees while increasing their average elevation by 3 m as a result of expansive valley filling. We estimate that in southern West Virginia, more than 6.4km(3) of bedrock has been broken apart and deposited into 1544 headwater valley fills. We used NPDES monitoring datatsets available for 91 of these valley fills to explore whether fill characteristics could explain variation in the pH or selenium concentrations reported for streams draining these fills. We found that the volume of overburden in individual valley fills correlates with stream pH and selenium concentration, and suggest that a three-dimensional assessment of mountaintop mining impacts is necessary to predict both the severity and the longevity of the resulting environmental impacts.

Metal contamination and post-remediation recovery in the Boulder River watershed, Jefferson County, Montana

USGS Publications Warehouse

Unruh, Daniel M.; Church, Stanley E; Nimick, David A.; Fey, David L.

2009-01-01

The legacy of acid mine drainage and toxic trace metals left in streams by historical mining is being addressed by many important yet costly remediation efforts. Monitoring of environmental conditions frequently is not performed but is essential to evaluate remediation effectiveness, determine whether clean-up goals have been met, and assess which remediation strategies are most effective. Extensive pre- and post-remediation data for water and sediment quality for the Boulder River watershed in southwestern Montana provide an unusual opportunity to demonstrate the importance of monitoring. The most extensive restoration in the watershed occurred at the Comet mine on High Ore Creek and resulted in the most dramatic improvement in aquatic habitat. Removal of contaminated sediment and tailings, and stream-channel reconstruction reduced Cd and Zn concentrations in water such that fish are now present, and reduced metal concentrations in streambed sediment by a factor of c. 10, the largest improvement in the district. Waste removals at the Buckeye/Enterprise and Bullion mine sites produced limited or no improvement in water and sediment quality, and acidic drainage from mine adits continues to degrade stream aquatic habitat. Recontouring of hillslopes that had funnelled runoff into the workings of the Crystal mine substantially reduced metal concentrations in Uncle Sam Gulch, but did not eliminate all of the acidic adit drainage. Lead isotopic evidence suggests that the Crystal mine rather than the Comet mine is now the largest source of metals in streambed sediment of the Boulder River. The completed removal actions prevent additional contaminants from entering the stream, but it may take many years for erosional processes to diminish the effects of contaminated sediment already in streams. Although significant strides have been made, additional efforts to seal draining adits or treat the adit effluent at the Bullion and Crystal mines would need to be completed to achieve the desired restoration.

Hydrology and model study of the proposed Prosperity Reservoir, Center Creek Basin, southwestern Missouri

USGS Publications Warehouse

Harvey, Edward Joseph; Emmett, Leo F.

1980-01-01

A dam and reservoir have been proposed for construction on Center Creek, Jasper County, in southwestern Missouri. Ground-water levels in the hills adjacent to the reservoir will rise when the impoundment is completed. One of the problems is that the proposed site of Prosperity Reservoir is a few miles upstream from the lead-zinc mining area known as the Oronogo-Duenweg belt. In this belt transmissivities are variable but appear to be higher than they are in the immediate area of the reservoir.Grove Creek lies down-gradient from the reservoir area and separates it from the mining belt. A model study indicates that inflow from the proposed reservoir to the water table could cause water level rises varying from about 20 feet near the reservoir to 0.5 to 1.0 foot in the southern part of Grove Creek drainage basin. These rises will cause significant changes to the natural ground-water flow system. Increased ground-water elevations in the reservoir area could result in increased ground-water gradients and discharge to Grove and Center Creeks. The increase in ground-water discharge to Grove Creek, and in turn Center Creek, will have the beneficial effect of diluting mine-water discharge from the Oronogo-Duenweg belt during periods of low flow.However, if Grove Creek does not act as an effective drain and if conduits extend beneath Grove Creek to transfer the increased water available to the Oronogo-Duenweg belt, the flow regimen could change in the mining belt west of Grove Creek increasing mine-water discharge to Center Creek downstream from the reservoir.Bedrock in the area is Mississippian limestone, the deeply solutioned formation that contained the ore deposits. The limestone in the mining district was greatly altered by solution prior to ore deposition while the limestone in the area of the reservoir was altered less. The extent of the alteration is related to the aquifer characteristics in that high and low values of transmissivity and storage coefficient correspond to greatly altered brecciated rocks in the mining district and less altered, less brecciated rocks in the reservoir area, respectively.The authors suggest that an ancestral east-flowing White River drained the area about Joplin in Late Mississippian time. This is based on the configuration of the contact between Meramecian and Osagean rocks of Mississippian age. A high topographic area existed in the region about Joplin in which the water table stood 200 feet below the land surface when sinkholes and caverns of that depth were formed. The large number of Pennsylvanian-filled sinkholes in the Joplin area and the smaller number to the east suggest a higher land surface to the west than that to the east. The distribution of paleokarst sinkholes supports the conclusion based on the configuration of the Meramecian-Osagean contact.

Factors controlling localization of uranium deposits in the Dakota Sandstone, Gallup and Ambrosia Lake mining districts, McKinley County, New Mexico

USGS Publications Warehouse

Pierson, Charles Thomas; Green, Morris W.

1977-01-01

Geologic studies were made at all of the uranium mines and prospects in the Dakota Sandstone of Early(?) and Late Cretaceous age in the Gallup mining district, McKinley County, New Mexico. Dakota mines in the adjacent Ambrosia Lake mining district were visited briefly for comparative purposes. Mines in the eastern part of the Gallup district, and in the Ambrosia Lake district, are on the Chaco slope of the southern San Juan Basin in strata which dip gently northward toward the central part of the basin. Mines in the western part of the Gallup district are along the Gallup hogback (Nutria monocline) in strata which dip steeply westward into the Gallup sag. Geologic factors which controlled formation of the uranium deposits in the Dakota Sandstone are: (1) a source of uranium, believed to be uranium deposits of the underlying Morrison Formation of Late Jurassic age; (2) the accessibility to the Dakota of uranium-bearing solutions from the Morrison; (3) the presence in the Dakota of permeable sandstone beds overlain by impermeable carbonaceous shale beds; and (4) the occurrence within the permeable Dakota sandstone beds of carbonaceous reducing material as bedding-plane laminae, or as pockets of carbonaceous trash. Most of the Dakota uranium deposits are found in the lower part of the formation in marginal-marine distributary-channel sandstones which were deposited in the backshore environment. However, the Hogback no. 4 (Hyde) Mine (Gallup district) occurs in sandy paludal shale of the backshore environment, and another deposit, the Silver Spur (Ambrosia Lake district), is found in what is interpreted to be a massive beach or barrier-bar sandstone of the foreshore environment in the upper part of the Dakota. The sedimentary depositional environment most favorable for the accumulation of uranium is that of backshore areas lateral to main distributary channels, where levee, splay, and some distributary-channel sandstones intertongue with gray carbonaceous shales and siltstones of the well-drained swamp environment. Deposits of black carbonaceous shale which were formed in the poorly drained swamp deposits of the interfluve area are not favorable host rocks for uranium. The depositional energy levels of the various environments in which the sandstone and shale beds of the Dakota were deposited govern the relative favorability of the strata as uranium host rocks. In the report area, uranium usually occurs in carbonaceous sandstone deposited under low- to medium-energy fluvial conditions within distributary channels. A prerequisite, however, is that such sandstone be overlain by impermeable carbonaceous shale beds. Low- to medium-energy fluvial conditions result in the deposition of sandstone beds having detrital carbonaceous material distributed in laminae or in trash pockets on bedding planes. The carbonaceous laminae and trash pockets provide the necessary reductant to cause precipitation of uranium from solution. High-energy fluvial conditions result in the deposition of sandstones having little or no carbonaceous material included to provide a reductant. Very low energy swampy conditions result in carbonaceous shale deposits, which are generally barren of uranium because of their relative impermeability to migrating uranium-bearing solutions.

Formation of a low-crystalline Zn-silicate in a stream in SW Sardinia, Italy

USGS Publications Warehouse

Wanty, Richard B.; De Giudici, G.; Onnis, P.; Rutherford, D.; Kimball, B.A.; Podda, F.; Cidu, R.; Lattanzi, P.; Medas, D.

2013-01-01

n southwestern Sardinia, Italy, the Rio Naracauli drains a catchment that includes several abandoned mines. The drainage from the mines and associated waste rocks has led to extreme concentrations of dissolved Zn, but because of the near-neutral pH, concentrations of other metals remain low. In the reach from approximately 2300 to 3000 m downstream from the headwaters area, an amorphous Zn-silicate precipitates from the water. In this reach, concentrations of both Zn and silica remain nearly constant, but the loads (measured in mass/time) of both increase, suggesting that new Zn and silica are supplied to the stream, likely from emerging groundwater. Zinc isotope signatures of the solid are heavier than the dissolved Zn by about 0.5 permil in 66/64Zn, suggesting that an extracellular biologically mediated adsorption process may be involved in the formation of the Zn-silicate.

Detecting change in water quality from implementation of limestone treatment systems in a coal-minded watershed

USGS Publications Warehouse

Cravotta,, Charles A.; Weitzel, Jeffrey B.

2000-01-01

During 1996-97, a variety of limestone-based treatment systems were implemented to neutralize acidic mine drainage and reduce the transport of dissolved metals in the northern part of the Swatara Creek watershed, which drains a 43-mi2 (112-km2) area in the Southern Anthracite Field upstream from Ravine, Pa. Since 1996, the current project has monitored water quality upstream and downstream of each treatment and at integrator sites on lower reaches of Swatara Creek. Continuous measurements of pH and specific conductance and periodic sampling for alkalinity, acidity, sulfate, and metals upstream and downstream of each treatment system show that (1) open limestone channels and limestone-sand dosing generally had negligible effects on water quality and (2) limestone diversion wells and limestone drains generally were effective at producing near-neutral pH and attenuating dissolved metals during baseflow but were less effective during stormflow conditions. Storm runoff in this area commonly is acidic, and, as streamflow volume increases during stormflow conditions, a smaller fraction of total flow is treated and (or) residence time in the treatment system is reduced. Monitoring on the mainstem of Swatara Creek indicates watershed-scale effects owing primarily to changes in mining practices and secondarily to watershed-wide implementation of treatment systems. Most underground mines in the Swatara Creek Basin were abandoned before 1960 and are presently flooded. Drainage from these mines contributes substantially to baseflow in Swatara Creek. For Swatara Creek at Ravine, Pa., which is immediately downstream of the mined area, long-term data collected since 1959 indicate sulfate concentration declined from about 150 mg/L in 1959 to 75 mg/L in 1999; pH increased sharply from 3.5-4.4 (median ~4) to 4.6-7.0 (median ~6) after 1975. These trends resulted from a decline in pyrite oxidation and the onset of carbonate buffering. Because these long-term attenuation processes have had such a pronounced effect on water quality in Swatara Creek, the effects of recent implementation of limestone treatments are difficult to detect at a watershed scale. Nevertheless, during ecological surveys prior to 1991, no fish were found in Swatara Creek at Ravine. Only six species of fish were found in 1994 and 1996. However, increasing numbers of fish have been found annually since 1996. In 1999, 21 species of fish were documented. The recent monitoring on the mainstem of Swatara Creek indicates the limestone treatments mitigate extreme fluctuations in pH during storm events; however, additional buffering capacity is needed to maintain near-neutral pH of Swatara Creek during large storm events. Concentration 2 of sulfate, specific conductance, and pH are inversely related to streamflow at Ravine, indicating dilution and acidification during stormflow. Declines in stream-water pH to values approaching 5.0 could result in the remobilization of adsorbed or precipitated metals associated with sediments; declines in pH below 5.0 could cause injury to aquatic organisms. Generally, to maintain stream pH during storms, additional or larger limestone diversion wells could be constructed to begin or increase alkalinity production as the stream stage rises and/or additional or larger limestone drains could be constructed to produce greater amounts of alkalinity and enhance the buffering capacity of baseflow.

Cyanide

USGS Publications Warehouse

Creekmore, Lynn H.

1999-01-01

Cyanide poisoning of birds is caused by exposure to cyanide in two forms: inorganic salts and hydrogen cyanide gas (HCN). Two sources of cyanide have been associated with bird mortalities: gold and silver mines that use cyanide in the extraction process and a predator control device called the M-44 sodium cyanide ejector, which uses cyanide as the toxic agent.Most of the cyanide mortality documented in birds is a result of exposure to cyanide used in heap leach and carbonin-pulp mill gold or silver mining processes. At these mines, the animals are exposed when they ingest water that contains cyanide salts used in mining processes or, possibly, when they inhale HCN gas. In heap leach mining operations, the ore is placed on an impermeable pad over which a cyanide solution is sprayed or dripped. The cyanide solution dissolves and attaches to or “leaches out” the gold. The cyanide and gold solution is then drained to a plastic-lined pond, which is commonly called the pregnant pond. The gold is extracted, and the remaining solution is moved into another lined pond, which is commonly called the barren pond. The cyanide concentration in this pond is increased so that the solution is again suitable for use in the leaching process, and the solution is used again on the ore heap (Fig. 46.1). Bird use of the HCN-contaminated water in the ponds (Fig. 46.2) or contaminated water on or at the base of the heap leach pads (Fig. 46.3) can result in mortality.

Water-quality assessment of the Cypress Creek watershed, Warrick County, Indiana

USGS Publications Warehouse

Bobo, Linda L.; Peters, Charles A.

1980-01-01

The U.S. Soil Conservation Service needs chemical, biological, microbiological, and hydrological data to prepare an environmental evaluation of the water quality in the Cypress Creek watershed, Warrick County, Ind., before plans can be devised to (1) improve water quality, (2) minimize flooding, (3) reduce sedimentation, and (4) provide adequate outlets for drainage in the watershed. The U.S. Geological Survey obtained these data for the Soil Conservation Service in a water-quality survey of the watershed from March to August 1979. Past and present surface coal mining is the factor having the greatest impact on water quality in the watershed. The upper reaches of Cypress Creek receive acid-mine drainage from a coal-mine waste slurry during periods of intense rainfall. All the remaining tributaries, except Summer Pecka ditch, drain mined or reclaimed lands. The general water type of Cypress Creek and most of its tributaries is calcium and magnesium sulfate. In contrast, the water type at background site 21 on Summer Pecka ditch is calcium sulfate. Specific conductance ranged from 470 to 4,730 micromhos per centimeter at 25 degrees Celsius, and pH ranged from 1.2 to 8.8. Specific conductance, hardness, and concentrations of major ions and dissolved solids were highest in tributaries affected by mining. The pH was lowest in the same tributaries. Concentrations of iron, manganese, and sulfate in water samples and chlordane, DDT, and PCB 's in streambed samples exceeded water-quality limits set by the U.S. Environmental Protection Agency. (USGS)

Antimony isotopic composition in river waters affected by ancient mining activity.

PubMed

Resongles, Eléonore; Freydier, Rémi; Casiot, Corinne; Viers, Jérôme; Chmeleff, Jérôme; Elbaz-Poulichet, Françoise

2015-11-01

In this study, antimony (Sb) isotopic composition was determined in natural water samples collected along two hydrosystems impacted by historical mining activities: the upper Orb River and the Gardon River watershed (SE, France). Antimony isotope ratio was measured by HG-MC-ICP-MS (Hydride Generation Multi-Collector Inductively Coupled Plasma Mass Spectrometer) after a preconcentration and purification step using a new thiol-cellulose powder (TCP) procedure. The external reproducibility obtained for δ(123)Sb measurements of our in-house Sb isotopic standard solution and a certified reference freshwater was 0.06‰ (2σ). Significant isotopic variations were evident in surface waters from the upper Orb River (-0.06‰≤δ(123)Sb≤+0.11‰) and from the Gardon River watershed (+0.27‰≤δ(123)Sb≤+0.83‰). In particular, streams that drained different former mining sites exploited for Sb or Pb-Zn exhibited contrasted Sb isotopic signature, that may be related to various biogeochemical processes occurring during Sb transfer from rocks, mine wastes and sediments to the water compartment. Nevertheless, Sb isotopic composition appeared to be stable along the Gardon River, which might be attributed to the conservative transport of Sb at distance from mine-impacted streams, due to the relative mobile behavior of Sb(V) in natural oxic waters. This study suggests that Sb isotopic composition could be a useful tool to track pollution sources and/or biogeochemical processes in hydrologic systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Geochemical investigations and interim recommendations for priority abandoned mine sites, BLM lands, upper Animas River watershed, San Juan County, Colorado

USGS Publications Warehouse

Nash, J. Thomas

1999-01-01

Field observations, sampling of mine dumps and mine drainage waters, and laboratory studies of dump materials have been made at mining areas deemed to be on public lands administered by the U. S. Bureau of Land Management (BLM) in the Upper Animas River watershed. Results of chemical analyses of dump materials, leachates of those materials, and surface waters draining mines or dumps provide indications of where acid is generated or consumed, and metal concentrations below mines or dumps. Information on sites previously identified as needing reclamation is reviewed and available geochemical information is used to rank 26 sites into four classes of priority for reclamation. Although there are more than a thousand mining sites (productive mines and prospects) on BLM lands in the Upper Animas River watershed study area, the majority are very small (less than about 70 cubic yards of dump material), are more than 2 miles from a major stream, or so inaccessible as to prohibit reclamation. In the summers of 1997 and 1998 approximately 200 sites were observed and more than 100 of these that appeared to have the potential to geochemically impact the watershed were examined more carefully and sampled. Building upon the prior work of the BLM and associated agencies, this work attempted to identify the most significant sources of mine-related contamination and to rank those sites as to priority for reclamation. These most significant mining areas have been examined within a geologic framework and were evaluated by multiple criteria, including tendency to generate acid and release toxic metals, observed damage to vegetation, potential to release metals based on leach tests, and likelihood of transport into streams of the watershed. No single measurable parameter, such as metal concentration, can be used to rank the sites. Rather, subjective estimates are required to evaluate combinations or interactions among several parameters. The most subjective estimate, while ranking feasibility of reclamation, is the relative amounts of naturally occurring metals and acidity and mine-related contamination at each mining area. Mitigation of natural contributions at mines or unmined areas is beyond the scope of my studies, but should be considered when planning reclamation. Available information for the 26 priority sites is adequate for ranking, but at some sites additional information on groundwater conditions is needed for a more complete site evaluation.

Comparison of Methane Control Methods in Polish and Vietnamese Coal Mines

NASA Astrophysics Data System (ADS)

Borowski, Marek; Kuczera, Zbigniew

2018-03-01

Methane hazard often occurs in hard coal mines and causes very serious accidents and can be the reason of methane or methane and coal dust explosions. History of coal mining shows that methane released from the rock mass to the longwall area was responsible for numerous mining disasters. The main source of methane are coal deposits because it is autochthonous gas and is closely related with carbonification and forming of coal deposits. Degree of methane saturation in coal deposits depends on numerous factors; mainly on presence or lack of insulating layers in cover deposit that allow or do not on degasification and easily methane outflow into surroundings. Hence in coal mining there are coal deposits that contain only low degree of methane saturation in places where is lack of insulating layers till high in methane coal deposits occurring in insulating claystones or in shales. Conducting mining works in coal deposits of high methane hazard without using of special measures to combat (ventilation, methane drainage) could be impossible. Control of methane hazard depends also on other co-occuring natural dangers for which used preventive actions eliminate methane hazard. Safety in mines excavating coal deposits saturated with methane depends on the correct estimation of methane hazard, drawn up forecasts, conducted observations, hazard control as well as undertaken prevention measures. Methane risk prevention includes identification and control methods of methane hazards as well as means of combating the explosive accumulation of methane in longwall workings. The main preventive actions in underground coal mines are: effective ventilation that prevents forming of methane fuses or placed methane accumulation in headings ventilated by airflow created by main fans and in headings with auxiliary ventilation, methane drainage using drain holes that are drilled from underground headings or from the surface, methanometry control of methane concentration in the air; location of the sensors is defined by law, additional ventilation equipment used in places of lower intensity of ventilation and places where methane is concentrated.

A comparison of the dynamics and bioconcentration of mercury in Oregon reservoirs

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

Park, J.; Curtis, L.

1995-12-31

The authors assessed the extent of mercury pollution and its bioconcentration effects in fish in two Oregon reservoirs. Cottage Grove and Dorena Reservoirs are located in same ecoregions but distinguished by the history of mercury mining in the formers watershed. Past mercury mining activity deposited up to 271 {micro}g/g mercury and 2.6 mg/g sulfur in soils of near Black Butte Mine, OR. Sediment mercury concentration in the main tributary of Cottage Grove Reservoir, which drains the tailings of the past mercury mine, was ten times higher than in sediment from other tributaries to the reservoir. However there was no significantlymore » difference between mercury concentration in each tributary of Dorena Reservoir, which has no mercury mining history in its watershed. Average mercury concentration in sediment of Cottage Grove Reservoir (0.67 {micro}g/g dw) was higher than of Dorena Reservoir (0.12 {micro}g/g dw). The authors also determined percent volatile solid and grain size effect in sediment. Maximum mercury concentration exceeded the FDA limit 1 {micro}g/g ww for largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus) in Cottage Grove Reservoir. All fish species (largemouth bass, bluegill, crappie (Pomoxis nigromaculatus), catfish (Ictalurus nebulosus)) from Cottage Grove Reservoir had significantly higher levels of mercury than from Dorena Reservoir. Fish weight and age was positively correlated with mercury concentration in both-reservoirs and seasonal variation of mercury concentration in fish was examined. These results indicate that the Black Butte Mine is the main source of mercury and mercury bioconcentration in fish represents a management problem in Cottage Grove Reservoir.« less

High altitude mine waste remediation -- Implementation of the Idarado remedial action plan

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

Hardy, A.J.; Redmond, J.V.; River, R.A.

1999-07-01

The Idarado Mine in Colorado's San Juan Mountains includes 11 tailing areas, numerous waste rock dumps, and a large number of underground openings connected by over 100 miles of raises and drifts. The tailings and mine wastes were generated from different mining and milling operations between 1975 and 1978. the Idarado Remedial Action Plan (RAP) was an innovative 5-year program developed for remediating the impacts of historic mining activities in the San Miguel River and Red Mountain Creek drainages. The challenges during implementation included seasonal access limitations due to the high altitude construction areas, high volumes of runoff during snowmore » melt, numerous abandoned underground openings and stopped-out veins, and high profile sites adjacent to busy jeep trails and a major ski resort town. Implementation of the RAP has included pioneering efforts in engineering design and construction of remedial measures. Innovative engineering designs included direct revegetation techniques for the stabilization of tailings piles, concrete cutoff walls and French drains to control subsurface flows, underground water controls that included pipelines, weeplines, and portal collection systems, and various underground structures to collect and divert subsurface flows often exceeding 2,000 gpm. Remote work locations have also required the use of innovative construction techniques such as heavy lift helicopters to move construction materials to mines above 10,000 feet. This paper describes the 5-year implementation program which has included over 1,000,000 cubic yards of tailing regrading, application of 5,000 tons of manure and 26,000 tons of limestone, and construction of over 10,000 feet of pipeline and approximately 45,000 feet of diversion channel.« less

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

Byrer, C.W.; Layne, A.W.; Guthrie, H.D.

The U.S. Department of Energy (DOE), at its Morgantown Energy Technology Center, has been involved in natural gas research since the 1970`s. DOE has assessed the potential of gas in coals throughout the U.S. and promoted research and development for recovery and use of methane found in minable and unminable coalbeds. DOE efforts have focused on the use of coal mine methane for regional economic gas self-sufficiency, energy parks, self-help initiatives, and small-power generation. This paper focuses on DOE`s past and present efforts to more effectively and efficiently recover and use this valuable domestic energy source. The Climate Change Actionmore » Plan (CCAP) (1) lists a series of 50 voluntary initiatives designed to reduce greenhouse gas emissions, such as methane from mining operations, to their 1990 levels. Action No. 36 of the CCAP expands the DOE research, development, and demonstration (RD&D) efforts to broaden the range of cost-effective technologies and practices for recovering methane associated with coal mining operations. The major thrust of Action No. 36 is to reduce methane emissions associated with coal mining operations from target year 2000 levels by 1.5 MMT of carbon equivalent. Crosscutting activities in the DOE Natural Gas Program supply the utilization sectors will address RD&D to reduce methane emissions released from various mining operations, focusing on recovery and end use technology systems to effectively drain, capture, and utilize the emitted gas. Pilot projects with industry partners will develop and test the most effective methods and technology systems for economic recovery and utilization of coal mine gas emissions in regions where industry considers efforts to be presently non-economic. These existing RD&D programs focus on near-term gas recovery and gathering systems, gas upgrading, and power generation.« less

Method for distinctive estimation of stored acidity forms in acid mine wastes.

PubMed

Li, Jun; Kawashima, Nobuyuki; Fan, Rong; Schumann, Russell C; Gerson, Andrea R; Smart, Roger St C

2014-10-07

Jarosites and schwertmannite can be formed in the unsaturated oxidation zone of sulfide-containing mine waste rock and tailings together with ferrihydrite and goethite. They are also widely found in process wastes from electrometallurgical smelting and metal bioleaching and within drained coastal lowland soils (acid-sulfate soils). These secondary minerals can temporarily store acidity and metals or remove and immobilize contaminants through adsorption, coprecipitation, or structural incorporation, but release both acidity and toxic metals at pH above about 4. Therefore, they have significant relevance to environmental mineralogy through their role in controlling pollutant concentrations and dynamics in contaminated aqueous environments. Most importantly, they have widely different acid release rates at different pHs and strongly affect drainage water acidity dynamics. A procedure for estimation of the amounts of these different forms of nonsulfide stored acidity in mining wastes is required in order to predict acid release rates at any pH. A four-step extraction procedure to quantify jarosite and schwertmannite separately with various soluble sulfate salts has been developed and validated. Corrections to acid potentials and estimation of acid release rates can be reliably based on this method.

Evaluation of coal-mining impacts using numerical classification of benthic invertebrate data from streams draining a heavily mined basin in eastern Tennessee

USGS Publications Warehouse

Bradfield, A.D.

1986-01-01

Coal-mining impacts on Smoky Creek, eastern Tennessee were evaluated using water quality and benthic invertebrate data. Data from mined sites were also compared with water quality and invertebrate fauna found at Crabapple Branch, an undisturbed stream in a nearby basin. Although differences in water quality constituent concentrations and physical habitat conditions at sampling sites were apparent, commonly used measures of benthic invertebrate sample data such as number of taxa, sample diversity, number of organisms, and biomass were inadequate for determining differences in stream environments. Clustering algorithms were more useful in determining differences in benthic invertebrate community structure and composition. Normal (collections) and inverse (species) analyses based on presence-absence data of species of Ephemeroptera, Plecoptera, and Tricoptera were compared using constancy, fidelity, and relative abundance of species found at stations with similar fauna. These analyses identified differences in benthic community composition due to seasonal variations in invertebrate life histories. When data from a single season were examined, sites on tributary streams generally clustered separately from sites on Smoky Creek. These analyses compared with differences in water quality, stream size, and substrate characteristics between tributary sites and the more degraded main stem sites, indicated that numerical classification of invertebrate data can provide discharge-independent information useful in rapid evaluations of in-stream environmental conditions. (Author 's abstract)

Analytical results for Bullion Mine and Crystal Mine waste samples and bed sediments from a small tributary to Jack Creek and from Uncle Sam Gulch, Boulder River watershed, Montana

USGS Publications Warehouse

Fey, David L.; Church, Stan E.; Finney, Christopher J.

2000-01-01

Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana affect water quality as a result of acid-generation and toxic-metal solubilization. Mine waste and tailings in the unnamed tributary to Jack Creek draining the Bullion mine area and in Uncle Sam Gulch below the Crystal mine are contributors to water quality degradation of Basin Creek and Cataract Creek, Montana. Basin Creek and Cataract Creek are two of three tributaries to the Boulder River in the study area. The bed sediment geochemistry in these two creeks has also been affected by the acidic drainage from these two mines. Geochemical analysis of 42 tailings cores and eleven bed-sediment samples was undertaken to determine the concentrations of Ag, As, Cd, Cu, Pb, and Zn present in these materials. These elements are environmentally significant, in that they can be toxic to fish and/or the invertebrate organisms in the aquatic food chain. Suites of one-inch cores of mine waste and tailings material were taken from two breached tailings impoundments near the site of the Bullion mine and from Uncle Sam Gulch below the Crystal mine. Forty-two core samples were taken and divided into 211 subsamples. The samples were analyzed by ICP-AES (inductively coupled plasma-atomic emission spectroscopy) using a mixed-acid (HC1-HNO3-HC1O4-HF) digestion. Results of the core analyses show that some samples contain moderate to very high concentrations of arsenic (as much as 13,000 ppm), silver (as much as 130 ppm), cadmium (as much as 260 ppm), copper (as much as 9,000 ppm), lead (as much as 11,000 ppm), and zinc (as much as 18,000 ppm). Eleven bed-sediment samples were also subjected to the mixed-acid total digestion, and a warm (50°C) 2M HC1-1% H2O2 leach and analyzed by ICP-AES. Results indicate that bed sediments of the Jack Creek tributary are impacted by past mining at the Bullion and Crystal mines. The contaminating metals are mostly contained in the 2M HC1-1% H2O2 leachable phase, which are the hydrous amorphous iron- and manganese-hydroxide coatings on detrital sediment particles.

Geochemical investigations and interim recommendations for priority abandoned mine sites on U.S.D.A. Forest Service lands, Mineral Creek watershed, San Juan County, Colorado

USGS Publications Warehouse

Nash, J.T.

1999-01-01

Field observations, sampling of mine dumps and mine drainage waters, and laboratory studies of dump materials have been made at mining areas deemed to be on public lands administered by the USDA Forest Service in the Mineral Creek watershed. Results of chemical analyses of dump materials, leachates of those materials, and of surface waters draining mines or dumps provide indications of where acid is generated or consumed, and what metals are mobilized below mines or dumps. Information on 25 sites is reviewed and reclamation priorities are ranked into four classes (high, medium, low priority, or no work required). The western side of the upper Animas watershed (the Mineral Creek watershed) has a history of mining and prospecting for about 130 years. The intensity of miningrelated disturbance is higher than in most parts of the San Juan Mountains region, but actually is much less than the eastern half of the watershed (US BLM lands) and none of the mines moved millions of tons of rock and ore as in some of the eastern mines. The majority of the roughly one thousand mining sites on the USFS lands are very small (less than 100 tons or 70 cubic yards of dump material), are more than 2 miles from a major stream, or are so inaccessible as to prohibit reclamation. Twenty five sites have been considered by others to have significant size and potential for significant environmental degradation. These most significant mining areas were evaluated by multiple criteria, including tendency to generate acid or liberate toxic metals, observed acidic pH or dead vegetation (?kill zones?) below dumps or adits, potential mobility of metals, and likelihood of transport into streams of the watershed. In the author?s opinion, no single measurable parameter, such as metal concentration, is reliable for ranking significance or feasibility of reclamation. Rather, subjective estimates are required to evaluate combinations of, or interactions among, several parameters. The most subjective estimate in ranking feasibility of reclamation is the amount of natural and mine-related contamination at each mining area. Mitigation of natural contributions at mines or unmined areas is beyond the scope of these Abandoned Mine Lands (AML) investigations, but must be considered when planning reclamation. Available information for the 25 problem sites is adequate for ranking, but at some sites additional information on groundwater conditions is needed for a more reliable ranking and evaluation of reclamation methods.

Metal loading in Soda Butte Creek upstream of Yellowstone National Park, Montana and Wyoming; a retrospective analysis of previous research; and quantification of metal loading, August 1999

USGS Publications Warehouse

Boughton, G.K.

2001-01-01

Acid drainage from historic mining activities has affected the water quality and aquatic biota of Soda Butte Creek upstream of Yellowstone National Park. Numerous investigations focusing on metals contamination have been conducted in the Soda Butte Creek basin, but interpretations of how metals contamination is currently impacting Soda Butte Creek differ greatly. A retrospective analysis of previous research on metal loading in Soda Butte Creek was completed to provide summaries of studies pertinent to metal loading in Soda Butte Creek and to identify data gaps warranting further investigation. Identification and quantification of the sources of metal loading to Soda Butte Creek was recognized as a significant data gap. The McLaren Mine tailings impoundment and mill site has long been identified as a source of metals but its contribution relative to the total metal load entering Yellowstone National Park was unknown. A tracer-injection and synoptic-sampling study was designed to determine metal loads upstream of Yellowstone National Park.A tracer-injection and synoptic-sampling study was conducted on an 8,511-meter reach of Soda Butte Creek from upstream of the McLaren Mine tailings impoundment and mill site downstream to the Yellowstone National Park boundary in August 1999. Synoptic-sampling sites were selected to divide the creek into discrete segments. A lithium bromide tracer was injected continuously into Soda Butte Creek for 24.5 hours. Downstream dilution of the tracer and current-meter measurements were used to calculate the stream discharge. Stream discharge values, combined with constituent concentrations obtained by synoptic sampling, were used to quantify constituent loading in each segment of Soda Butte Creek.Loads were calculated for dissolved calcium, silica, and sulfate, as well as for dissolved and total-recoverable iron, aluminum, and manganese. Loads were not calculated for cadmium, copper, lead, and zinc because these elements were infrequently detected in mainstem synoptic samples. All of these elements were detected at high concentrations in the seeps draining the McLaren Mine tailings impoundment. The lack of detection of these elements in the downstream mainstem synoptic samples is probably because of sorption (coprecipitation and adsorption) to metal colloids in the stream.Most of the metal load that entered Soda Butte Creek was contributed by the inflows draining the McLaren Mine tailings impoundment (between 505 meters and 760 meters downstream from the tracer-injection site), Republic Creek (1,859 meters), and Unnamed Tributary (8,267 meters). Results indicate that treatment or removal of the McLaren Mine tailings impoundment would greatly reduce metal loading in Soda Butte Creek upstream of Yellowstone National Park. However, removing only that single source may not reduce metal loads to acceptable levels. The sources of metal loading in Republic Creek and Unnamed Tributary merit further investigation.

Environmental impact assessment of sand mining from the small catchment rivers in the southwestern coast of India: a case study.

PubMed

Sreebha, Sreedharan; Padmalal, Damodaran

2011-01-01

In the past few decades, the demand for construction grade sand is increasing in many parts of the world due to rapid economic development and subsequent growth of building activities. This, in many of the occasions, has resulted in indiscriminate mining of sand from in-stream and floodplain areas leading to severe damages to the river basin environment. The case is rather alarming in the small catchment rivers like those draining the southwestern coast of India due to limited sand resources in their alluvial reaches. Moreover, lack of adequate information on the environmental impact of river sand mining is a major lacuna challenging regulatory efforts in many developing countries. Therefore, a scientific assessment is a pre-requisite in formulating management strategies in the sand mining-hit areas. In this context, a study has been made as a case to address the environmental impact of sand mining from the in-stream and floodplain areas of three important rivers in the southwestern coast of India namely the Chalakudy, Periyar and Muvattupuzha rivers, whose lowlands host one of the fast developing urban-cum-industrial centre, the Kochi city. The study reveals that an amount of 11.527 million ty(-1) of sand (8.764 million ty(-1) of in-stream sand and 2.763 million ty(-1) of floodplain sand) is being mined from the midland and lowland reaches of these rivers for construction of buildings and other infrastructural facilities in Kochi city and its satellite townships. Environmental Impact Assessment (EIA) carried out as a part of this investigation shows that the activities associated with mining and processing of sands have not only affected the health of the river ecosystems but also degraded its overbank areas to a large extent. Considering the degree of degradation caused by sand mining from these rivers, no mining scenario may be opted in the deeper zones of the river channels. Also, a set of suggestions are made for the overall improvement of the rivers and its biophysical environment.

Environmental Impact Assessment of Sand Mining from the Small Catchment Rivers in the Southwestern Coast of India: A Case Study

NASA Astrophysics Data System (ADS)

Sreebha, Sreedharan; Padmalal, Damodaran

2011-01-01

In the past few decades, the demand for construction grade sand is increasing in many parts of the world due to rapid economic development and subsequent growth of building activities. This, in many of the occasions, has resulted in indiscriminate mining of sand from instream and floodplain areas leading to severe damages to the river basin environment. The case is rather alarming in the small catchment rivers like those draining the southwestern coast of India due to limited sand resources in their alluvial reaches. Moreover, lack of adequate information on the environmental impact of river sand mining is a major lacuna challenging regulatory efforts in many developing countries. Therefore, a scientific assessment is a pre-requisite in formulating management strategies in the sand mining-hit areas. In this context, a study has been made as a case to address the environmental impact of sand mining from the instream and floodplain areas of three important rivers in the southwestern coast of India namely the Chalakudy, Periyar and Muvattupuzha rivers, whose lowlands host one of the fast developing urban-cum-industrial centre, the Kochi city. The study reveals that an amount of 11.527 million ty-1 of sand (8.764 million ty-1 of instream sand and 2.763 million ty-1 of floodplain sand) is being mined from the midland and lowland reaches of these rivers for construction of buildings and other infrastructural facilities in Kochi city and its satellite townships. Environmental Impact Assessment (EIA) carried out as a part of this investigation shows that the activities associated with mining and processing of sands have not only affected the health of the river ecosystems but also degraded its overbank areas to a large extent. Considering the degree of degradation caused by sand mining from these rivers, no mining scenario may be opted in the deeper zones of the river channels. Also, a set of suggestions are made for the overall improvement of the rivers and its biophysical environment.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Radioactivity in the environment; a case study of the Puerco and Little Colorado River basins, Arizona and New Mexico

USGS Publications Warehouse

Wirt, Laurie

1994-01-01

This report, written for the nontechnical reader, summarizes the results of a study from 1988-91 of the occurrence and transport of selected radionuclides and other chemical constituents in the Puerco and Little Colorado River basins, Arizona and New Mexico. More than two decades of uranium mining and the 1979 failure of an earthen dam containing mine tailings released high levels of radionuclides and other chemical constituents to the Puerco River, a tributary of the Little Colorado River. Releases caused public concern that ground water and streamflow downstream from mining were contaminated. Study findings show which radioactive elements are present, how these elements are distributed between water and sediment in the environment, how concentrations of radioactive elements vary naturally within basins, and how levels of radioactivity have changed since the end of mining. Although levels of radioactive elements and other trace elements measured in streamflow commonly exceed drinking-water standards, no evidence was found to indicate that the high concentrations were still related to uraniurn mining. Sediment radioactivity was higher at sample sites on streams that drain the eastern part of the Little Colorado River basin than that of samples from the western part. Radioactivity of suspended sediment measured in this study, therefore, represents natural conditions for the streams sampled rather than an effect of mining. Because ground water beneath the Puerco River channel is shallow, the aquifer is vulnerable to contamination. A narrow zone of ground water beneath the Puerco River containing elevated uranium concentrations was identified during the study. The highest concentrations were nearest the mines and in samples collected in the first few feet beneath the streambed. Natuxal radiation levels in a few areas of the underlying sedimentary aquifer not connected to the Puerco River also exceeded water quality standards. Water testing would enable those residents not using public water supplies to determine if their water is safe to use.

Comparison of peak discharges among sites with and without valley fills for the July 8-9, 2001 flood in the headwaters of Clear Fork, Coal River basin, mountaintop coal-mining region, southern West Virginia

USGS Publications Warehouse

Wiley, Jeffrey B.; Brogan, Freddie D.

2003-01-01

The effects of mountaintop-removal mining practices on the peak discharges of streams were investigated in six small drainage basins within a 7-square-mile area in southern West Virginia. Two of the small basins had reclaimed valley fills, one basin had reclaimed and unreclaimed valley fills, and three basins did not have valley fills. Indirect measurements of peak discharge for the flood of July 8-9, 2001, were made at six sites on streams draining the small basins. The sites without valley fills had peak discharges with 10- to 25-year recurrence intervals, indicating that rainfall intensities and totals varied among the study basins. The flood-recurrence intervals for the three basins with valley fills were determined as though the peak discharges were those from rural streams without the influence of valley fills, and ranged from less than 2 years to more than 100 years.

Is air pollution causing landslides in China?

NASA Astrophysics Data System (ADS)

Zhang, Ming; McSaveney, Mauri J.

2018-01-01

Air pollution in China often exceeds "unhealthy" levels, but Chinese air is not only a threat from being breathed: the pollutants may also be causing fatal landslides. Very acid rain from severe air pollution falls widely in southwest China, where coal is a major energy source. We discuss where acid rain may provide an unsuspected link between mining and the fatal 2009 Jiweishan landslide in southwest China; it may have reduced the strength of a thin, calcareous, black sapropelic shale in Jiweishan Mountain by removing cementing carbonate minerals and sapropel matrix. Mining beneath the potential slide mass may not have directly triggered the landslide, but collapse of abandoned adits drained a perched aquifer above a regional black-shale aquiclude. Inflow of acid, oxygenated water and nutrients into the aquiclude may have accelerated the reduction of strength of the weakest rocks and consequently led to rapid sliding of a large rock mass on a layer of weathered shale left composed largely of soft, and slippery talc.

Diel mercury-concentration variations in streams affected by mining and geothermal discharge

USGS Publications Warehouse

Nimick, D.A.; McCleskey, R. Blaine; Gammons, C.H.; Cleasby, T.E.; Parker, S.R.

2007-01-01

Diel variations of concentrations of unfiltered and filtered total Hg and filtered methyl Hg were documented during 24-h sampling episodes in water from Silver Creek, which drains a historical gold-mining district near Helena, Montana, and the Madison River, which drains the geothermal system of Yellowstone National Park. The concentrations of filtered methyl Hg had relatively large diel variations (increases of 68 and 93% from morning minima) in both streams. Unfiltered and filtered (0.1-??m filtration) total Hg in Silver Creek had diel concentration increases of 24% and 7%, respectively. In the Madison River, concentrations of unfiltered and filtered total Hg did not change during the sampling period. The concentration variation of unfiltered total Hg in Silver Creek followed the diel variation in suspended-particle concentration. The concentration variation of filtered total and methyl Hg followed the solar photocycle, with highest concentrations during the early afternoon and evening and lowest concentrations during the morning. None of the diel Hg variations correlated with diel variation in streamflow or major ion concentrations. The diel variation in filtered total Hg could have been produced by adsorption-desorption of Hg2+ or by reduction of Hg(II) to Hg0 and subsequent evasion of Hg0. The diel variation in filtered methyl Hg could have been produced by sunlight- and temperature-dependent methylation. This study is the first to examine diel Hg cycling in streams, and its results reinforce previous conclusions that diel trace-element cycling in streams is widespread but often not recognized and that parts of the biogeochemical Hg cycle respond quickly to the daily photocycle. ?? 2006 Elsevier B.V. All rights reserved.

Effects of Historical Coal Mining and Drainage from Abandoned Mines on Streamflow and Water Quality in Newport and Nanticoke Creeks, Luzerne County, Pennsylvania, 1999-2000

USGS Publications Warehouse

Chaplin, Jeffrey J.; Cravotta,, Charles A.; Weitzel, Jeffrey B.; Klemow, Kenneth M.

2007-01-01

This report characterizes the effects of historical mining and abandoned mine drainage (AMD) on streamflow and water quality and evaluates potential strategies for AMD abatement in the 14-square-mile Newport Creek Basin and 7.6-square-mile Nanticoke Creek Basin. Both basins are mostly within the Northern Anthracite Coal Field and drain to the Susquehanna River in central Luzerne County, Pa. The U.S. Geological Survey (USGS), in cooperation with the Earth Conservancy, conducted an assessment from April 1999 to September 2000 that included (1) continuous stage measurement at 7 sites; (2) synoptic water-quality and flow sampling at 21 sites on June 2-4, 1999, and at 24 sites on October 7-8, 1999; and (3) periodic measurement of flow and water quality at 26 additional sites not included in the synoptic sampling effort. Stream water and surface runoff from the unmined uplands drain northward to the valley, where most of the water is intercepted and diverted into abandoned underground mines. Water that infiltrates into the mine workings becomes loaded with acidity, metals, and sulfate and later discharges as AMD at topographically low points along lower reaches of Newport Creek, Nanticoke Creek, and their tributaries. Differences among streamflows in unmined and mined areas of the watersheds indicated that (1) intermediate stream reaches within the mined area but upgradient of AMD sites generally were either dry or losing reaches, (2) ground water flowing to AMD sites could cross beneath surface-drainage divides, and (3) AMD discharging to the lower stream reaches restored volumes lost in the upstream reaches. The synoptic data for June and October 1999, along with continuous stage data during the study period, indicated flows during synoptic surveys were comparable to average values. The headwaters upstream of the mined area generally were oxygenated (dissolved oxygen range was 4.7 to 11.0 mg/L [milligrams per liter]), near-neutral (pH range was 5.8 to 7.6), and net alkaline (net alkalinity range was 2.0 to 25.0 mg/L CaCO3), with relatively low concentrations of sulfate (6.40 to 24.0 mg/L) and dissolved metals (less than 500 ug/L [micrograms per liter] of iron, manganese, and aluminum). In contrast, the AMD discharges and downstream waters were characterized by elevated concentrations of sulfate and dissolved metals that exceeded Federal and State regulatory limits. The largest AMD sources were the Susquehanna Number 7 Mine discharge entering Newport Creek near its mouth (flow range was 4.7 to 19 ft3/s [cubic feet per second]), the Truesdale Mine Discharge (Dundee Outfall) entering Nanticoke Creek about 0.5 mile upstream of Loomis Park (flow range was 0.00 to 38 ft3/s), and a mine-pit overflow entering near the midpoint of Newport Creek (flow range was 4.0 to 6.9 ft3/s). The three large discharges were poorly oxygenated (dissolved oxygen concentration range was <0.05 to 6.4 mg/L) and had elevated concentrations of sulfate (range was 710 to 890 mg/L) and low concentrations of dissolved aluminum (less than 25 ug/L), but they had distinctive concentrations of net alkalinity and dissolved iron and manganese. Effluent from the Susquehanna Number 7 Mine was near-neutral (pH range was 5.9 to 6.6) and net alkaline (net alkalinity range was 12.0 to 42.0 mg/L CaCO3) with elevated concentrations of sulfate (718 to 1,170 mg/L), dissolved iron (52,500 to 77,400 ug/L), and manganese (5,200 to 5,300 ug/L). Effluent from the Truesdale Mine also was near-neutral (pH range was 5.9 to 6.3) but had variable net alkalinity (-19.0 to 57.0 mg/L CaCO3) with elevated concentrations of sulfate (571 to 740 mg/L), dissolved iron (30,500 to 43,000 ug/L), and manganese (3,600 to 5,200 ug/L). Effluent from the mine-pit overflow in Newport Creek Basin was acidic (pH range was 4.3 to 5.0; net alkalinity range was -42 to -38 mg/L CaCO3) with elevated concentrations of sulfate (800 to 840 mg/L), iron (13,000 to 16,000 ug/L), and manganese (6,800 to 7,000 ug

Hydrology and potential effects of mining in the Quitchupah and Pines coal-lease tracts, central Utah

USGS Publications Warehouse

Thiros, Susan A.; Cordy, G.E.

1991-01-01

Bydrologic data were collected for the proposed Quitchupah and Pines coal-lease tracts in Sevier and Bnery Counties, Utah, in order to describe the hydrology and potential effects of mining on the hydrologic system. The Quitchupah and Pines coal-lease tracts are near the Southern Utah Fuel Company coal mine in an area of the central Wasatch Plateau that is characterized by a relatively flat plateau deeply dissected by steep-sided canyons.Surface water in the Quitchupah and Pines study area drains to two perennial streams, Muddy Creek to the north and Quitchupah Creek to the south. Peak streamflow is usually in May and June in response to snowmelt runoff; however, thunderstorms can cause short-term high flows in late summer and fall. The specific conductance of surface water in and near the study area measured during the 1987 water year ranged from 440 (iS/cm to 860 (iS/cm. Suspended-sediment concentrations ranged from 17 to 10,900 mg/L in the Quitchupah Creek drainage and 34 to 312 mg/L in the Muddy Creek drainage.Stable-isotope studies indicate that recharge to aquifers in the study area is by seepage of snowmelt into rock outcrops. Discharge from the aquifers is at springs, seeps, mines, and zones of seepage in streambeds. The chemical quality of ground water is related to the mineralogy of the formations with which the water has contact. Water from the upper part of the Cast legate Sandstone has the smallest concentration of dissolved solids, 61 mg/L, and water from the North Horn Formation has the largest concentration, 1,080 mg/L.Observed effects of underground coal mining at the nearby active mine are considered indicative of the changes that can be expected in the Quitchupah and Pines coal-lease tracts. Subsidence above the mined area could cause dewatering of the Blackhawk Formation and the Star Point Sandstone, changes in the natural drainage patterns, and alteration of both surface- and ground-water quality. Additional studies are needed to gain a better understanding of the hydrologic effects of underground mining in the Quitchupah and Pines coal-lease tracts.

Aquatic ecosystems in Central Colorado are influenced by mineral forming processes and historical mining

USGS Publications Warehouse

Schmidt, T.S.; Church, S.E.; Clements, W.H.; Mitchell, K.A.; Fey, D. L.; Wanty, R.B.; Verplanck, P.L.; San, Juan C.A.; Klein, T.L.; deWitt, E.H.; Rockwell, B.W.

2009-01-01

Stream water and sediment toxicity to aquatic insects were quantified from central Colorado catchments to distinguish the effect of geologic processes which result in high background metals concentrations from historical mining. Our sampling design targeted small catchments underlain by rocks of a single lithology, which allowed the development of biological and geochemical baselines without the complication of multiple rock types exposed in the catchment. By accounting for geologic sources of metals to the environment, we were able to distinguish between the environmental effects caused by mining and the weathering of different mineralized areas. Elevated metal concentrations in water and sediment were not restricted to mined catchments. Impairment of aquatic communities also occurred in unmined catchments influenced by hydrothermal alteration. Hydrothermal alteration style, deposit type, and mining were important determinants of water and sediment quality and aquatic community structure. Weathering of unmined porphyry Cu-Mo occurrences resulted in water (median toxic unit (TU) = 108) and sediment quality (TU = 1.9) that exceeded concentrations thought to be safe for aquatic ecosystems (TU = 1). Metalsensitive aquatic insects were virtually absent from streams draining catchments with porphyry Cu-Mo occurrences (1.1 individuals/0.1 m2 ). However, water and sediment quality (TU = 0.1, 0.5 water and sediment, respectively) and presence of metalsensitive aquatic insects (204 individuals/0.1 m2 ) for unmined polymetallic vein occurrences were indistinguishable from that for unmined and unaltered streams (TU = 0.1, 0.5 water and sediment, respectively; 201 individuals/0.1 m2 ). In catchments with mined quartz-sericite-pyrite altered polymetallic vein deposits, water (TU = 8.4) and sediment quality (TU = 3.1) were degraded and more toxic to aquatic insects (36 individuals/0.1 m2 ) than water (TU = 0.4) and sediment quality (TU = 1.7) from mined propylitically altered polymetallic vein deposits. The sampling approach taken in this study distinguishes the effects of different mineral deposits on ecosystems and can be used to more accurately quantify the effect of mining on the environment. 

Naturally acidic surface and ground waters draining porphyry-related mineralized areas of the Southern Rocky Mountains, Colorado and New Mexico

USGS Publications Warehouse

Verplanck, P.L.; Nordstrom, D. Kirk; Bove, D.J.; Plumlee, G.S.; Runkel, R.L.

2009-01-01

Acidic, metal-rich waters produced by the oxidative weathering and resulting leaching of major and trace elements from pyritic rocks can adversely affect water quality in receiving streams and riparian ecosystems. Five study areas in the southern Rocky Mountains with naturally acidic waters associated with porphyry mineralization were studied to document variations in water chemistry and processes that control the chemical variations. Study areas include the Upper Animas River watershed, East Alpine Gulch, Mount Emmons, and Handcart Gulch in Colorado and the Red River in New Mexico. Although host-rock lithologies in all these areas range from Precambrian gneisses to Cretaceous sedimentary units to Tertiary volcanic complexes, the mineralization is Tertiary in age and associated with intermediate to felsic composition, porphyritic plutons. Pyrite is ubiquitous, ranging from ???1 to >5 vol.%. Springs and headwater streams have pH values as low as 2.6, SO4 up to 3700 mg/L and high dissolved metal concentrations (for example: Fe up to 400 mg/L; Cu up to 3.5 mg/L; and Zn up to 14.4 mg/L). Intensity of hydrothermal alteration and presence of sulfides are the primary controls of water chemistry of these naturally acidic waters. Subbasins underlain by intensely hydrothermally altered lithologies are poorly vegetated and quite susceptible to storm-induced surface runoff. Within the Red River study area, results from a storm runoff study documented downstream changes in river chemistry: pH decreased from 7.80 to 4.83, alkalinity decreased from 49.4 to <1 mg/L, SO4 increased from 162 to 314 mg/L, dissolved Fe increased from to 0.011 to 0.596 mg/L, and dissolved Zn increased from 0.056 to 0.607 mg/L. Compared to mine drainage in the same study areas, the chemistry of naturally acidic waters tends to overlap but not reach the extreme concentrations of metals and acidity as some mine waters. The chemistry of waters draining these mineralized but unmined areas can be used to estimate premining conditions at sites with similar geologic and hydrologic conditions. For example, the US Geological Survey was asked to estimate premining ground-water chemistry at the Questa Mo mine, and the proximal analog approach was used because a mineralized but unmined area was located adjacent to the mine property. By comparing and contrasting water chemistry from different porphyry mineralized areas, this study not only documents the range in concentrations of constituents of interest but also provides insight into the primary controls of water chemistry.

Colloidal mobilization of arsenic from mining-affected soils by surface runoff.

PubMed

Gomez-Gonzalez, Miguel Angel; Voegelin, Andreas; Garcia-Guinea, Javier; Bolea, Eduardo; Laborda, Francisco; Garrido, Fernando

2016-02-01

Scorodite-rich wastes left as a legacy of mining and smelting operations pose a threat to environmental health. Colloids formed by the weathering of processing wastes may control the release of arsenic (As) into surface waters. At a former mine site in Madrid (Spain), we investigated the mobilization of colloidal As by surface runoff from weathered processing wastes and from sediments in the bed of a draining creek and a downstream sedimentation-pond. Colloids mobilized by surface runoff during simulated rain events were characterized for their composition, structure and mode of As uptake using asymmetric flow field-flow fractionation coupled to inductively plasma mass spectrometry (AF4-ICP-MS) and X-ray absorption spectroscopy (XAS) at the As and Fe K-edges. Colloidal scorodite mobilized in surface runoff from the waste pile is acting as a mobile As carrier. In surface runoff from the river bed and the sedimentation pond, ferrihydrite was identified as the dominant As-bearing colloidal phase. The results from this study suggest that mobilization of As-bearing colloids by surface runoff may play an important role in the dispersion of As from metallurgical wastes deposited above ground and needs to be considered in risk assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Appraisal of ground water in the vicinity of the Leadville drainage tunnel, Lake County, Colorado

USGS Publications Warehouse

Turk, John T.; Taylor, O. James

1979-01-01

Ground water in the Leadville mining district occurs in granite, quartzite, limestone, sandstone, porphyry dikes, and unconsolidated material. These rocks form a single aquifer system because the formations are hydraulically connected through contact, mine workings, faulting, and fracturing. The aquifer is recharged by precipitation and water moves toward California Gulch and probably toward Evans Gulch, in the drainage basin of the Arkansas River. The Leadville drainage tunnel was constructed from 1943 to 1945 and later extended during 1950 to 1952, in order to drain the mine workings. Discharge from the tunnel lowered water levels 30 to 96 feet in mine shafts from 1944 to 1951. Installation of an impervious plug in the tunnel has been proposed in order to reduce the discharge of water containing objectionable concentrations of trace metals into the East Fork Arkansas River. The proposed plug would reduce the discharge from the tunnel, cause water levels east of the town of Leadville to rise, flood some mine workings, and increase ground-water discharge to California Gulch. However, the proposed plug is not expected to cause water levels in Leadville to rise substantially, but more current and detailed data are needed to verify this. Discharge from the Leadville drainage tunnel is probably a mixture of water in equilibrium with carbonate aquifer materials from the mineralized zone, water acidified by the localized oxidation of pyrite from the mineralized zone, and water nearly saturated with calcite from the glacial mantle. Based on limited data, water from the carbonate mineral deposits has a pH of about 7.0 and concentrations of manganese of about 1,800 micrograms per liter and zinc concentrations of about 13,000 micrograms per liter. (USGS)

Analytical and numerical simulation of the steady-state hydrologic effects of mining aggregate in hypothetical sand-and-gravel and fractured crystalline-rock aquifers

USGS Publications Warehouse

Arnold, L.R.; Langer, William H.; Paschke, Suzanne Smith

2003-01-01

Analytical solutions and numerical models were used to predict the extent of steady-state drawdown caused by mining of aggregate below the water table in hypothetical sand-and-gravel and fractured crystalline-rock aquifers representative of hydrogeologic settings in the Front Range area of Colorado. Analytical solutions were used to predict the extent of drawdown under a wide range of hydrologic and mining conditions that assume aquifer homogeneity, isotropy, and infinite extent. Numerical ground-water flow models were used to estimate the extent of drawdown under conditions that consider heterogeneity, anisotropy, and hydrologic boundaries and to simulate complex or unusual conditions not readily simulated using analytical solutions. Analytical simulations indicated that the drawdown radius (or distance) of influence increased as horizontal hydraulic conductivity of the aquifer, mine penetration of the water table, and mine radius increased; radius of influence decreased as aquifer recharge increased. Sensitivity analysis of analytical simulations under intermediate conditions in sand-and-gravel and fractured crystalline-rock aquifers indicated that the drawdown radius of influence was most sensitive to mine penetration of the water table and least sensitive to mine radius. Radius of influence was equally sensitive to changes in horizontal hydraulic conductivity and recharge. Numerical simulations of pits in sand-and- gravel aquifers indicated that the area of influence in a vertically anisotropic sand-and-gravel aquifer of medium size was nearly identical to that in an isotropic aquifer of the same size. Simulated area of influence increased as aquifer size increased and aquifer boundaries were farther away from the pit, and simulated drawdown was greater near the pit when aquifer boundaries were close to the pit. Pits simulated as lined with slurry walls caused mounding to occur upgradient from the pits and drawdown to occur downgradient from the pits. Pits simulated as refilled with water and undergoing evaporative losses had little hydro- logic effect on the aquifer. Numerical sensitivity analyses for simulations of pits in sand-and-gravel aquifers indicated that simulated head was most sensitive to horizontal hydraulic conductivity and the hydraulic conductance of general-head boundaries in the models. Simulated head was less sensitive to riverbed conductance and recharge and relatively insensitive to vertical hydraulic conductivity. Numerical simulations of quarries in fractured crystalline-rock aquifers indicated that the area of influence in a horizontally anisotropic aquifer was elongated in the direction of higher horizontal hydraulic conductivity and shortened in the direction of lower horizontal hydraulic conductivity compared to area of influence in a homogeneous, isotropic aquifer. Area of influence was larger in an aquifer with ground-water flow in deep, low-permeability fractures than in a homogeneous, isotropic aquifer. Area of influence was larger for a quarry intersected by a hydraulically conductive fault zone and smaller for a quarry intersected by a low-conductivity fault zone. Numerical sensitivity analyses for simulations of quarries in fractured crystalline-rock aquifers indicated simulated head was most sensitive to variations in recharge and horizontal hydraulic conductivity, had little sensitivity to vertical hydraulic conductivity and drain cells used to simulate valleys, and was relatively insensitive to drain cells used to simulate the quarry.

Water quality of the Swatara Creek Basin, PA

USGS Publications Warehouse

McCarren, Edward F.; Wark, J.W.; George, J.R.

1964-01-01

The Swatara Creek of the Susquehanna River Basin is the farthest downstream sub-basin that drains acid water (pH of 4.5 or less) from anthracite coal mines. The Swatara Creek drainage area includes 567 square miles of parts of Schuylkill, Berks, Lebanon, and Dauphin Counties in Pennsylvania.To learn what environmental factors and dissolved constituents in water were influencing the quality of Swatara Creek, a reconnaissance of the basin was begun during the summer of 1958. Most of the surface streams and the wells adjacent to the principal tributaries of the Creek were sampled for chemical analysis. Effluents from aquifers underlying the basin were chemically analyzed because ground water is the basic source of supply to surface streams in the Swatara Creek basin. When there is little runoff during droughts, ground water has a dominating influence on the quality of surface water. Field tests showed that all ground water in the basin was non-acidic. However, several streams were acidic. Sources of acidity in these streams were traced to the overflow of impounded water in unworked coal mines.Acidic mine effluents and washings from coal breakers were detected downstream in Swatara Creek as far as Harper Tavern, although the pH at Harper Tavern infrequently went below 6.0. Suspended-sediment sampling at this location showed the mean daily concentration ranged from 2 to 500 ppm. The concentration of suspended sediment is influenced by runoff and land use, and at Harper Tavern it consisted of natural sediments and coal wastes. The average daily suspended-sediment discharge there during the period May 8 to September 30, 1959, was 109 tons per day, and the computed annual suspended-sediment load, 450 tons per square mile. Only moderate treatment would be required to restore the quality of Swatara Creek at Harper Tavern for many uses. Above Ravine, however, the quality of the Creek is generally acidic and, therefore, of limited usefulness to public supplies, industries and recreation. In general, the quality of Swatara Creek improves after it mixes with water from the Upper Little and Lower Little Swatara Creeks, which converge with the main stream near Pine Grove. Jonestown is the first downstream location where Swatara Creek contains bicarbonate ion most of the time, and for the remaining downstream length of the stream, the concentration of bicarbonate progressively increases. Before the stream enters the Susquehanna River, chemical and diluting processes contributed by tributaries change the acidic calcium sulfate water, which characterizes the upper Swatara, to a calcium bicarbonate water.A major tributary to Swatara Creek is Quittapahilla Creek, which drains a limestone region and has alkaline characteristics. Effluents from a sewage treatment plant are discharged into this stream west of Lebanon. Adjacent to the Creek are limestone quarries and during the recovery of limestone, ground water seeps into the mining areas. This water is pumped to upper levels and flows over the land surface into Quittapahilla Creek. As compared with the 1940's, the quality of Swatara Creek is better today, and the water is suitable for more uses. In large part, this improvement is due to curtailment of anthracite coal mining and because of the controls imposed on new mines, stripping mines, and the related coal mining operations, by the Pennsylvania Sanitary Water Board. Thus, today (1962) smaller amounts of coal mine wastes are more effectively flushed and scoured away with each successive runoff during storms that affect the drainage basin. Natural processes neutralizing acid water in the stream by infiltration of alkaline ground water through springs and through the streambed are also indicated.

Geochemical data for core and bottom-sediment samples collected in 2007 from Grand Lake O' the Cherokees, northeast Oklahoma

USGS Publications Warehouse

Fey, David L.; Becker, Mark F.; Smith, Kathleen S.

2010-01-01

Grand Lake O' the Cherokees is a large reservoir in northeast Oklahoma, below the confluence of the Neosho and Spring Rivers, both of which drain the Tri-State Mining District to the north. The Tri-State district covers an area of 1,200 mi2 (3,100 km2) and comprises Mississippi Valley-type lead-zinc deposits. A result of 120 years of mining activity is an estimated 75 million tons of processed mine tailings (chat) remaining in the district. Concerns of sediment quality and the possibility of human exposure to cadmium and lead through eating fish have led to several studies of the sediments in the Tri-State district. In order to record the transport and deposition of metals from the Tri-State district by the Spring and Neosho Rivers into Grand Lake O' the Cherokees, the U.S. Geological Survey collected 11 sediment cores and 15 bottom-sediment samples in September 2007. Subsamples from five selected cores and the bottom-sediment samples were analyzed for major and trace elements and forms of carbon. The sediment samples collected from the sediment-water interface had larger average concentrations of zinc, cadmium, and lead than local background. The core collected from the Spring River had the largest concentrations of mining-related elements. A core collected just south of Twin Bridges State Park, at the confluence of the Spring and Neosho Rivers, showed a mixing zone with more mining-related elements coming from the Spring River side. The element zinc showed the most definitive patterns in graphs depicting concentration-versus-depth profiles. A core collected from the main body of the reservoir showed affected sediment down to a depth of 85 cm (33 in). This core and two others appear to have penetrated to below mining-affected sediment.

A Novel Uncultured Bacterium of the Family Gallionellaceae: Description and Genome Reconstruction Based on the Metagenomic Analysis of Microbial Community in Acid Mine Drainage.

PubMed

Kadnikov, V V; Ivasenko, D A; Beletsky, A V; Mardanov, A V; Danilova, E V; Pimenov, N V; Karnachuk, O V; Ravin, N V

2016-07-01

Drainage waters at the metal mining areas often have low pH and high content of dissolved metals due to oxidation of sulfide minerals. Extreme conditions limit microbial diversity in- such ecosystems. A drainage water microbial community (6.5'C, pH 2.65) in an open pit at the Sherlovaya Gora polymetallic open-cast mine (Transbaikal region, Eastern Siberia, Russia) was studied using metagenomic techniques. Metagenome sequencing provided information for taxonomic and functional characterization of the micro- bial community. The majority of microorganisms belonged to a single uncultured lineage representing a new Betaproteobacteria species of the genus Gallionella. While no.acidophiles are known among the cultured members of the family Gallionellaceae, similar 16S rRNA gene sequences were detected in acid mine drain- ages. Bacteria ofthe genera Thiobacillus, Acidobacterium, Acidisphaera, and Acidithiobacillus,-which are com- mon in acid mine drainage environments, were the minor components of the community. Metagenomic data were -used to determine the almost complete (-3.4 Mb) composite genome of the new bacterial. lineage desig- nated Candidatus Gallionella acididurans ShG14-8. Genome analysis revealed that Fe(II) oxidation probably involved the cytochromes localized on the outer membrane of the cell. The electron transport chain included NADH dehydrogenase, a cytochrome bc1 complex, an alternative complex III, and cytochrome oxidases of the bd, cbb3, and bo3 types. Oxidation of reduced sulfur compounds probably involved the Sox system, sul- fide-quinone oxidoreductase, adenyl sulfate reductase, and sulfate adenyltransferase. The genes required for autotrophic carbon assimilation via the Calvin cycle were present, while no pathway for nitrogen fixation was revealed. High numbers of RND metal transporters and P type ATPases were probably responsible for resis- tance to heavy metals. The new microorganism was an aerobic chemolithoautotroph of the group of psychrotolerant iron- and sulfur-oxidizing acidophiles of the family Gallionellaceae, which are common in acid mine drainages.

Temporal variation and the effect of rainfall on metals flux from the historic Beatson mine, Prince William Sound, Alaska, USA

USGS Publications Warehouse

Stillings, L.L.; Foster, A.L.; Koski, R.A.; Munk, L.; Shanks, Wayne C.

2008-01-01

Several abandoned Cu mines are located along the shore of Prince William Sound, AK, where the effect of mining-related discharge upon shoreline ecosystems is unknown. To determine the magnitude of this effect at the former Beatson mine, the largest Cu mine in the region and a Besshi-type massive sulfide ore deposit, trace metal concentration and flux were measured in surface run-off from remnant, mineralized workings and waste. Samples were collected from seepage waters; a remnant glory hole which is now a pit lake; a braided stream draining an area of mineralized rock, underground mine workings, and waste piles; and a background location upstream of the mine workings and mineralized rock. In the background stream pH averaged ???7.3, specific conductivity (SC) was ???40 ??S/cm, and the aqueous components indicative of sulfide mineral weathering, SO4 and trace metals, were at detection limits or lower. In the braided stream below the mine workings and waste piles, pH usually varied from 6.7 to 7.1, SC varied from 40 to 120 ??S/cm, SO4 had maximum concentrations of 32 mg/L, and the trace metals Cu, Ni, Pb, and Zn showed maximum total acid extractable concentrations of 186, 5.9, 6.2 and 343 ??g/L, respectively. With an annual rainfall of ???340 cm (estimated from the 2006 water year) it was expected that rain water would have a large effect on the chemistry of the braided stream draining the mine site. A linear mixing model with two end members, seepage water from mineralized rock and background water, estimated that the braided stream contained 10-35% mine drainage. After rain events the braided stream showed a decrease in pH, SC, Ca + Mg, SO4, and alkalinity, due to dilution. The trace metals Ni and Zn followed this same pattern. Sodium + K and Cl did not vary between the background and braided stream, nor did they vary with rainfall. At approximately 2 and 3 mg/L, respectively, these concentrations are similar to concentrations found in rainfall on the coasts of North America. High concentrations of total acid extractable Al and Fe were found at near-neutral pH in most of the waters collected at the site. Equilibrium solubility simulations, performed with PHREEQC, show that the stream waters are saturated with respect to Al, Fe and SiO2 solid phases. Because the "dissolved" sample fractions (acid preserved and filtered to 0.45 ??m) show significant concentrations of Al and Fe it is presumed that these are present as colloids. The relationship between concentrations of Al and Fe, and rainfall was the opposite of that observed for the major ions Ca + Mg, SO4, and alkalinity, in that Al and Fe concentrations increased with increasing rainfall. Concentrations of Cu and Pb followed the same pattern. Adsorption calculations were performed with Visual MINTEQ, using the diffuse double layer electrostatic model and surface complexation constants for the ferrihydrite surface. These results suggest that 30-93% of Cu and 58-97% of Pb was adsorbed to ferrihydrite precipitates in the stream waters. Ni and Zn showed little adsorption in this pH range. Flux calculations show that the total mass of trace metals transported from the mine site, during the 60 day study period, was ranked as Zn (196 kg) > Cu (87 kg) > Pb(1.9 kg) ??? Ni(1.9 kg). Nickel and Zn were transported mostly as dissolved species while Cu and Pb were transported mostly as adsorbed species. pH control on adsorption was evident when Cu and Pb isotherms were normalized by ferrihydrite flux. Decreased stream water pH due to periods of frequent and high volume rain events would cause desorption of Cu and Pb from the ferrihydrite surface, thus changing not only their speciation in solution but also their mechanism of transport. ?? 2007 Elsevier Ltd. All rights reserved.

Hydrology and hydraulics of treatment wetlands constructed on drained peatlands

NASA Astrophysics Data System (ADS)

Postila, Heini; Ronkanen, Anna-Kaisa; Kløve, Bjørn

2013-04-01

Treatment wetlands are globally used for wastewater purification purposes. In Finland, these wetlands are commonly peatland-based and are used to treat runoff from peat extraction sites and peatland forestry. Wetlands are also used for polishing municipal wastewaters and mining waters. In peat extraction the structures are usually called overland flow areas (OFAs), which are traditionally established on pristine peatlands. However, nowadays establishing of new peat extraction sites is guided to drained peatland areas due to the Finnish Peat Use Strategy, which leads difficulties to find undisturbed peatland area for OFA. Therefore treatment wetlands have had to construct also on drained peatland areas. In drained areas peat physical properties have changed due to oxidation and subsidence and the water flow pathways differs from OFAs flow patterns, which maybe have effect on purification results. Thus in the present study we aim to clarify the hydrology and hydraulic properties of treatment wetlands constructed on drained peatland areas. For this purposes, 20 treatment wetlands on drained peatland areas across Finland were detailed measured for peat hydraulic conductivity. In selected areas, runoff was continuously monitored, flow distribution at treatment areas was studied and water residence times measured with tracer tests using potassium iodide (KI). Generally, in the study areas, the ditches had been completely blocked, partly blocked e.g with peat dams or not blocked at all. The ditches were located partly parallel to the flow direction and partly perpendicular to it. The distribution of water to the wetlands has been implemented in many different ways e.g. by distribution ditch or by perforated pipes. Based on the results, in majority of the wetlands, the peat drainage has clearly affected the hydraulic properties of wetlands, but not on all sites. In more than half of the wetlands (12), the median hydraulic conductivity of peat drastically decreased at the depth below 20 cm (or 10 cm). Two site it decreased at the depth of 40 cm, and at five sites, it was high at all depth investigated (down to 60-70 cm). The outflow proportion to inflow varied from 20 % to 97 %, which means that the part of the water infiltrated into the groundwater. Evaporation can explain part of the observed reduced water flow especially in dense tree stands. More than half of the wetlands contained also dry areas, meaning that treatment wetlands constructed on drained area have problems with even water distribution to the wetland. Ditches are also potential preferential flow paths and the shortest observed residence time was less than one day, but a much longer residence time was also recorded. The water flow in these treatment wetlands consequently occur only at the surface layer (0-20 cm) of peat, not deeper, or in the ditches, which may have impact on water purification results.

Metals transport in the Sacramento River, California, 1996-1997; Volume 2: Interpretation of metal loads

USGS Publications Warehouse

Alpers, Charles N.; Antweiler, Ronald C.; Taylor, Howard E.; Dileanis, Peter D.; Domagalski, Joseph L.

2000-01-01

Metals transport in the Sacramento River, northern California, from July 1996 to June 1997 was evaluated in terms of metal loads from samples of water and suspended colloids that were collected on up to six occasions at 13 sites in the Sacramento River Basin. Four of the sampling periods (July, September, and November 1996; and May-June 1997) took place during relatively low-flow conditions and two sampling periods (December 1996 and January 1997) took place during high-flow and flooding conditions, respectively. This study focused primarily on loads of cadmium, copper, lead, and zinc, with secondary emphasis on loads of aluminum, iron, and mercury.Trace metals in acid mine drainage from abandoned and inactive base-metal mines, in the East and West Shasta mining districts, enter the Sacramento River system in predominantly dissolved form into both Shasta Lake and Keswick Reservoir. The proportion of trace metals that was dissolved (as opposed to colloidal) in samples collected at Shasta and Keswick dams decreased in the order zinc ≈ cadmium > copper > lead. At four sampling sites on the Sacramento River--71, 256, 360, and 412 kilometers downstream of Keswick Dam--trace-metal loads were predominantly colloidal during both high- and low-flow conditions. The proportion of total cadmium, copper, lead, and zinc loads transported to San Francisco Bay and the Sacramento-San Joaquin Delta estuary (referred to as the Bay-Delta) that is associated with mineralized areas was estimated by dividing loads at Keswick Dam by loads 412 kilometers downstream at Freeport and the Yolo Bypass. During moderately high flows in December 1996, mineralization-related total (dissolved + colloidal) trace-metal loads to the Bay-Delta (as a percentage of total loads measured downstream) were cadmium, 87 percent; copper, 35 percent; lead, 10 percent; and zinc, 51 percent. During flood conditions in January 1997 loads were cadmium, 22 percent; copper, 11 percent; lead, 2 percent; and zinc, 15 percent. During irrigation drainage season from rice fields (May-June 1997) loads were cadmium, 53 percent; copper, 42 percent; lead, 20 percent; and zinc, 75 percent. These estimates must be qualified by the following factors: (1) metal loads at Colusa in December 1996 and at Verona in May-June 1997 generally exceeded those determined at Freeport during those sampling periods. Therefore, the above percentages represent maximum estimates of the apparent total proportion of metals from mineralized areas upstream of Keswick Dam; and (2) for logistics reasons, the Sacramento River was sampled at Tower Bridge instead of at Freeport during January 1997.Available data suggest that trace metal loads from agricultural drainage may be significant during certain flow conditions in areas where metals such as copper and zinc are added as agricultural amendments. Copper loads for sampling periods in July and September 1996 and in May-June 1997 show increases of dissolved and colloidal copper and in colloidal zinc between Colusa and Verona, the reach of the Sacramento River along which the Colusa Basin Drain, the Sacramento Slough, and other agricultural return flows are tributaries. Monthly sampling of these two agricultural drains by the USGS National Water-Quality Assessment Program shows seasonal variations in metal concentrations, reaching maximum concentrations of 4 to 6 micrograms per liter in "dissolved" (0.45-micrometer filtrate) copper concentrations in May 1996, December 1996, and June 1997. The total (dissolved plus colloidal) load of copper from the Colusa Basin Drain in June 1997 was 18 kilograms per day, whereas the copper load in Spring Creek, which drains the inactive mines on Iron Mountain, was 20 kilograms per day during the same sampling period. For comparison, during the January 1997 flood, the copper load in Spring Creek was about 1,100 kilograms per day and the copper load in the Yolo Bypass was about 7,300 kilograms per day. The data clearly indicate that most copper and zinc loads during the January 1997 flood entered the Sacramento River upstream of Colusa, and upstream of the influence of the most intense agricultural drainage return flows in the Sacramento River watershed.This study has demonstrated that some trace metals of environmental significance (cadmium, copper, and zinc) in the Sacramento River are transported largely in dissolved form at upstream sites (below Shasta Dam, below Keswick Dam, and at Bend Bridge) proximal to the mineralized areas of the West Shasta and East Shasta mining districts. In contrast, these trace metals are transported largely in colloidal form at downstream sites (Colusa, Verona, Freeport, and Yolo Bypass). Aluminum, iron, and lead were observed to be transported predominantly in the colloidal phase at all mainstem Sacramento River sampling sites during all sampling periods in this study. Despite continuous water treatment, which has removed 85 to 90 percent of the cadmium, copper, and zinc from the mine drainage at Iron Mountain, Spring Creek remains a significant source of these metals to the Sacramento River system.

Metals in riparian wildlife of the lead mining district of southeastern Missouri

USGS Publications Warehouse

Niethammer, K.R.; Atkinson, R.D.; Baskett, T.S.; Samson, F.B.

1985-01-01

Five species of riparian vertebrates (425 individuals) primarily representing upper trophic levels were collected from the Big River and Black River drainages in two lead mining districts of southeastern Missouri, 1981?82. Big River is subject to metal pollution via erosion and seepage from large tailings piles from inactive lead mines. Black River drains part of a currently mined area. Bullfrogs (Rana catesbeiana), muskrats (Ondatra zibethicus), and green-backed herons (Butorides striatus) collected downstream from the source of metal contamination to Big River had significantly (ANOVA, P<0.05) higher lead and cadmium levels than specimens collected at either an uncontaminated upstream site or on Black River. Northern water snakes (Nerodia sipedon) had elevated lead levels below the tailings source, but did not seem to accumulate cadmium. Levels of lead, cadmium, or zinc in northern rough-winged swallows (Stelgidopteryx serripennis) were not related to collecting locality. Carcasses of ten bank swallows (Riparia riparia) collected from a colony nesting in a tailings pile along the Big River had lead concentrations of 2.0?39 ppm wet weight. Differences between zinc concentrations in vertebrates collected from contaminated and uncontaminated sites were less apparent than differences in lead and cadmium. There was little relationship between metal concentrations in the animals studied and their trophic levels. Bullfrogs are the most promising species examined for monitoring environmental levels of lead, cadmium, and zinc. Downstream from the source of tailings, bullfrogs had markedly higher levels of these metals in most of their tissues. The species is also widely distributed in North America, easily caught, and relatively sedentary.

Hydrological modeling of a watershed affected by acid mine drainage (Odiel River, SW Spain). Assessment of the pollutant contributing areas

NASA Astrophysics Data System (ADS)

Galván, L.; Olías, M.; Cánovas, C. R.; Sarmiento, A. M.; Nieto, J. M.

2016-09-01

The Odiel watershed drains materials belonging to the Iberian Pyrite Belt, where significant massive sulfide deposits have been mined historically. As a result, a huge amount of sulfide-rich wastes are deposited in the watershed, which suffer from oxidation, releasing acidic lixiviates with high sulfate and metal concentrations. In order to reliably estimate the metal loadings along the watershed a complete series of discharge and hydrochemical data are essential. A hydrological model was performed with SWAT (Soil and Water Assessment Tool) to solve the scarcity of gauge stations along the watershed. The model was calibrated and validated from daily discharge data (from 1980 to 2010) at the outlet of the watershed, river inputs into an existent reservoir, and a flow gauge station close to the northern area of the watershed. Discharge data obtained from the hydrological model, together with analytical data, allowed the estimation of the dissolved pollutant load delivered annually by the Odiel River (e.g. 9140 t of Al, 2760 t of Zn). The pollutant load is influenced strongly by the rainfall regime, and can even double during extremely rainy years. Around 50% of total pollution comes from the Riotinto Mining District, so the treatment of Riotinto lixiviates reaching the Odiel watershed would reduce the AMD (Acid Mine Drainages) in a remarkable way, improving the water quality downstream, especially in the reservoir of Alcolea, currently under construction. The information obtained in this study will allow the optimization of remediation efforts in the watershed, in order to improve its water quality.

Mercury concentrations of fish, river water, and sediment in the Río Ramis-Lake Titicaca watershed, Peru.

PubMed

Gammons, Christopher H; Slotton, Darell G; Gerbrandt, Butch; Weight, Willis; Young, Courtney A; McNearny, Richard L; Cámac, Eugenio; Calderón, Ruben; Tapia, Henri

2006-09-15

This study reports the first set of data on the concentration of mercury in muscle tissue of several varieties of fish from Lake Titicaca, including the pejerrey (Basilichthyes bonariensis), the carachi (Orestias), and 2 types of indigenous catfish (Trichomycterus). Approximately 27% of the pejerrey and 75% of the carachi exceeded the US EPA fish tissue-based water quality criterion level of 0.30 microg g(-1). Mercury levels of pejerrey increased with fish size, although this relationship was less apparent for the smaller carachi. The pejerrey and carachi are important food fish for local residents. A synoptic sampling of the Río Ramis--the largest tributary to Lake Titicaca--was conducted in an attempt to determine if mercury releases from artisanal gold mining could be an important source of Hg contamination to Lake Titicaca. Although highly elevated concentrations of Hg and other heavy metals were documented in headwater streams near the mining centers of La Rinconada and Cecilia, the quantity of Hg entering Lake Titicaca that could be attributed to mining in the Ramis watershed was below the quantifiable limit in our July 2002 study. This does not diminish the localized threat to mercury exposure for the artisanal gold miners themselves, as well as their families. Further studies of mercury dynamics in Lake Titicaca are recommended, as well as in the rivers draining into the lake. It is probable that most of the downgradient transport of Hg and other trace metals from the headwater mining centers occurs as suspended sediment during seasonal periods of high-flow.

Stream-sediment geochemistry in mining-impacted streams: Prichard, Eagle, and Beaver creeks, northern Coeur d'Alene Mining District, northern Idaho

USGS Publications Warehouse

Box, Stephen E.; Wallis, John C.; Briggs, Paul H.; Brown, Zoe Ann

2005-01-01

This report presents the results of one aspect of an integrated watershed-characterization study that was undertaken to assess the impacts of historical mining and milling of silver-lead-zinc ores on water and sediment composition and on aquatic biota in streams draining the northern part of the Coeur d?Alene Mining District in northern Idaho. We present the results of chemical analyses of 62 samples of streambed sediment, 19 samples of suspended sediment, 23 samples of streambank soil, and 29 samples of mine- and mill-related artificial- fill material collected from the drainages of Prichard, Eagle, and Beaver Creeks, all tributaries to the North Fork of the Coeur d?Alene River. All samples were sieved into three grain-size fractions (<0.063, 0.063?0.25, and 0.25?1.0 mm) and analyzed for 40 elements after four-acid digestion by inductively coupled plasma atomic-emission spectrometry and for mercury by continuous- flow cold-vapor atomic-absorption spectrometry in the U.S. Geological Survey laboratory in Denver, Colo. Historical mining of silver-lead-zinc ores in the headwater reaches of the Prichard Creek, Eagle Creek, and Beaver Creek drainages has resulted in enrichments of lead, zinc, mercury, arsenic, cadmium, silver, copper, cobalt, and, to a lesser extent, iron and manganese in streambed sediment. Using samples collected from the relatively unimpacted West Fork of Eagle Creek as representative of background compositions, streambed sediment in the vicinity of the mines and millsites has Pb and Zn contents of 20 to 100 times background values, decreasing to 2 to 5 times background values at the mouth of the each stream, 15 to 20 km downstream. Lesser enrichments (<10 times background values) of mercury and arsenic also are generally associated with, and decrease downstream from, historical silver-lead-zinc mining in the drainages. However, enrichments of arsenic and, to a lesser extent, mercury also are areally associated with the lode gold deposits along Prichard Creek near Murray, which were not studied here. Metal contents in samples of unfractionated suspended sediment collected during a high-flow event in April 2000 are generally similar to, but slightly higher than, those in the fine (<0.063- mm grain size) fraction of streambed sediment from the same sampling site. Although metal enrichment in streambed sediment typically begins adjacent to the mine portals and their associated mine-waste rock dumps, volumetrically larger inputs of metal-enriched materials were contributed by the ore-concentration millsites and their associated, more finely ground, more metal rich mill-tailings impoundments.

Environmental assessment of water, sediment, and biota collected from the Bear Creek watershed, Colusa County, California

USGS Publications Warehouse

Rytuba, James J.; Hothem, Roger L.; Brussee, Brianne E.; Goldstein, Daniel; May, Jason T.

2015-01-01

The Cache Creek watershed lies within California's North Coast Range, an area with abundant geologic sources of mercury (Hg) and a long history of Hg contamination (Rytuba, 2000). Bear Creek, Cache Creek, and the North Fork of Cache Creek are the major streams of the Cache Creek watershed, encompassing 2978 km2. The Cache Creek watershed contains soils naturally enriched in Hg as well as natural springs (both hot and cold) with varying levels of aqueous Hg (Domagalski and others, 2004, Suchanek and others, 2004, Holloway and others 2009). All three tributaries are known to be significant sources of anthropogenically derived Hg from historic mines, both Hg and gold (Au), and associated ore storage/processing sites and facilities (Slotton and others, 1995, 2004; CVRWQCB, 2003; Schwarzbach and others, 2001; Gassel and others, 2005; Suchanek and others., 2004, 2008a, 2009). Historically, two of the primary sources of mercury contamination in the upper part of Bear Creek have been the Rathburn and Petray Hg Mines. The Rathburn Hg mine was discovered and initially mined in the early 1890s. The Rathburn and the more recently developed Petray open pit mines are localized along fault zones in serpentinite that has been altered and cut by quartz and chalcedony veins. Cold saline-carbonate springs are located perepheral to the Hg deposits and effluent from the springs locally has high concentrations of Hg (Slowey and Rytuba, 2008). Several ephemeral tributaries to Bear Creek drain the mine area which is located on federal land managed by the U.S. Bureau of Land Management (USBLM). The USBLM requested that the U.S. Geological Survey (USGS) measure and characterize Hg and other geochemical constituents in sediment, water, and biota to establish baseline information prior to remediation of the Rathburn and Petray mines. Samples sites were established in Bear Creek upstream and downstream from the mine area. This report is made in response to the USBLM request, the lead agency mandated to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - Removal Site Investigation (RSI). The RSI applies to the possible removal of Hg-contaminated mine waste from Bear Creek. This report summarizes data obtained from field sampling of water, sediment, and biota in Bear Creek, above input from the mine area and downstream from the Rathburn-Petray mine area to the confluence with Cache Creek. Our results permit a preliminary assessment of the chemical constituents that could elevate levels of monomethyl Hg (MMeHg) in Bear Creek and its uptake by biota and provide baseline information for comparison to conditions after mine remediation is completed.

Assessing the fate of explosives derived nitrate in mine waste rock dumps using the stable isotopes of oxygen and nitrogen.

PubMed

Hendry, M Jim; Wassenaar, Leonard I; Barbour, S Lee; Schabert, Marcie S; Birkham, Tyler K; Fedec, Tony; Schmeling, Erin E

2018-05-29

Ammonium nitrate (NH 4 NO 3 ) mixed with fuel oil is a common blasting agent used to fragment rock into workable size fractions at mines throughout the world. The decomposition and oxidation of undetonated explosives can result in high NO 3 - concentrations in waters emanating from waste rock dumps. We used the stable isotopic composition of NO 3 - (δ 15 N- and δ 18 O-NO 3 - ) to define and quantify the controls on NO 3 - composition in waste rock dumps by studying water-unsaturated and saturated conditions at nine coal waste rock dumps located in the Elk Valley, British Columbia, Canada. Estimates of the extent of nitrification of NH 4 NO 3 in oxic zones in the dumps, initial NO 3 - concentrations prior to denitrification, and the extent of NO 3 - removal by denitrification in sub-oxic to anoxic zones are provided. δ 15 N data from unsaturated waste rock dumps confirm NO 3 - is derived from blasting. δ 15 N- and δ 18 O-NO 3 - data show extensive denitrification can occur in saturated waste rock and in localized zones of elevated water saturation and low oxygen concentrations in unsaturated waste rock. At the mine dump scale, the extent of denitrification in the unsaturated waste rock was inferred from water samples collected from underlying rock drains. Copyright © 2018. Published by Elsevier B.V.

A geochemical approach to the restoration plans for the Odiel River basin (SW Spain), a watershed deeply polluted by acid mine drainage.

PubMed

Macías, Francisco; Pérez-López, Rafael; Caraballo, Manuel A; Sarmiento, Aguasanta M; Cánovas, Carlos R; Nieto, Jose M; Olías, Manuel; Ayora, Carlos

2017-02-01

The Odiel River Basin (SW Spain) drains the central part of the Iberian Pyrite Belt (IPB), a world-class example of sulfide mining district and concomitantly of acid mine drainage (AMD) pollution. The severe AMD pollution and the incipient state of remediation strategies implemented in this region, coupled with the proximity of the deadline for compliance with the European Water Framework Directive (WFD), urge to develop a restoration and water resources management strategy. Furthermore, despite the presence of some reservoirs with acid waters in the Odiel basin, the construction of the Alcolea water reservoir has already started. On the basis of the positive results obtained after more than 10 years of developing a specific passive remediation technology (dispersed alkaline substrate (DAS)) for the highly polluted AMD of this region, a restoration strategy is proposed. The implementation of 13 DAS treatment plants in selected acid discharges along the Odiel and Oraque sub-basins and other restoration measurements of two acidic creeks is proposed as essential to obtain a good water quality in the future Alcolea reservoir. This restoration strategy is also suggested as an economically and environmentally sustainable approach to the extreme metal pollution affecting the waters of the region and could be considered the starting point for the future compliance with the WFD in the Odiel River Basin.

Water resources and the hydrologic effects of coal mining in Washington County, Pennsylvania

USGS Publications Warehouse

Williams, Donald R.; Felbinger, John K.; Squillace, Paul J.

1993-01-01

Washington County occupies an area of 864 square miles in southwestern Pennsylvania and lies within the Pittsburgh Plateaus Section of the Appalachian Plateaus physiographic province. About 69 percent of the county population is served by public water-supply systems, and the Monongahela River is the source for 78 percent of the public-supply systems. The remaining 31 percent of the population depends on wells, springs, and cisterns for its domestic water supply. The sedimentary rocks of Pennsylvanian and Permian age that underlie the county include sandstone, siltstone, limestone, shale, and coal. The mean reported yield of bedrock wells ranges from 8.8 gallons per minute in the Pittsburgh .Formation to 46 gallons per minute in the Casselman Formation. Annual water-level fluctuations usually range from less than 3 ft (feet) beneath a valley to about 16 ft beneath a hilltop. Average hydraulic conductivity ranges from 0.01 to 18 ft per day. Water-level fluctuations and aquifer-test results suggest that most ground water circulates within 150 ft of land surface. A three-dimensional computer flow-model analysis indicates 96 percent of the total ground-water recharge remains in the upper 80 to 110 ft of bedrock (shallow aquifer system). The regional flow system (more than 250ft deep in the main valley) receives less than 0.1 percent of the total ground-water recharge from the Brush Run basin. The predominance of the shallow aquifer system is substantiated by driller's reports, which show almost all water bearing zones are less than 150ft below land surface. The modeling of an unmined basin showed that the hydrologic factors that govern regional groundwater flow can differ widely spatially but have little effect on the shallow aquifers that supply water to most domestic wells. However, the shallow aquifers are sensitive to hydrologic factors within this shallow aquifer system (such as ground-water recharge, hydraulic conductivity of the streamaquifer interface, and hydraulic conductivity of the aquifer). A vertical fracture zone would probably increase ground-water availability within the zone and would probably result in a lower head in the shallow aquifers in an upland draw area and an increased head in a valley. l Streams in the northern and western parts of the county drain to the Ohio River and streams in the eastern and southern parts of the county drain to the Monongahela River. The computed 7-day, 10-year low-flow frequencies for the surface-water sites ranged from 0.0 to 55 x 10-3 cubic feet per second per square mile. The lowest low-flow discharges per square mile were in the south-central and southwestern parts of the county. The highest low-flow discharges per square mile were in the eastern and northern parts of the county. The annual water loss at five gaged streams ranged from 52 to 75 percent of the total precipitation. The loss resulted from evaporation, transpiration, diversion, mines, ground-water outflow from the system, and plant and animal consumption. The major ground-water-quality problems are elevated concentrations of iron, manganese, and dissolved solids, and very hard water. Minor groundwater-quality problems include elevated concentrations of fluoride, chloride, and sulfate. Downgradient along the ground-water flow path, principal ions change from mostly calcium, magnesium, sulfate, and bicarbonate to sodium and chloride. Dissolyed-solids concentrations generally increase with residence time .. Elevated concentrations of sulfate and total dissolved solids were common at the surface-water sites in the northern and eastern parts of the county where most of the active and abandohed coal mines are located and where acid mine drainage is most prevalent. However, measured alkalinity at most of the surface-water sites ranged from 86 to 345 milligrams per liter, indicating that these streams would have a neutralizing effect on most inflows of acid mine drainage. The model of the hypothetically mined Brush Run basin shows that the vertical hydraulic conductivity (either existing or induced by mine subsidence) between the shallow ground-water system and the mine, and the depth to the mine are critical controls on the amount of ground water entering the mine. When the vertical hydraulic conductivity was increased by a factor of four for a mine about 250 ft deep in the main valley, inflow to the mine increased almost by the same factor. The model also shows that increasing the depth to a mine by 200 ft (mine about 450 ft deep in main valley) would cause mine inflow to decrease one order of magnitude. Comparisons between stream discharges during low base-flow conditions in a mined basin (Daniels Run) and an unrnined basin (Brush Run) indicated that the deep mining did not substantially lower streamflow. Although streamflow decreased and, at times, completely disappeared in the middle and lower parts of Daniels Run basin, it reappeared again downstream as ground-water discharge and was part of the flow at the mouth of Daniels Run. Comparison of the water-quality characteristics of the two basins showed that concentrations of dissolved solids, sulfate, sodium, chloride, fluoride, and manganese were greater in the mined basin than in the unmined basin. The pH and iron concentrations were similar in both basins.

Laboratory and field evaluation of a flushable oxic limestone drain for treatment of net-acidic drainage from a flooded anthracite mine, Pennsylvania, USA

USGS Publications Warehouse

Cravotta, C.A.

2008-01-01

This paper demonstrates the use of dissolution-rate data obtained in the laboratory to indicate the potential quality of effluent from a field-scale oxic limestone drain (OLD) treatment system for neutralization of dilute acidic mine drainage (AMD). Effluent from the Reevesdale Mine South Dip Tunnel, a large source of AMD and base flow to the Wabash Creek and Little Schuylkill River in the Southern Anthracite Coalfield of east-central Pennsylvania, is representative of AMD with low concentrations but high loadings of dissolved Fe, Al and other metals because of a high flow rate. In January 2003, rapid neutralization of the AMD from the Reevesdale Mine was achieved in laboratory tests of its reaction rate with crushed limestone in closed, collapsible containers (Cubitainers). The tests showed that net-alkaline effluent could be achieved with retention times greater than 3 h and that effluent alkalinities and associated dissolution rates were equivalent for Fe(OH)3-coated and uncoated limestone. On the basis of the laboratory results, a flushable OLD containing 1450 metric tons of high-purity calcitic limestone followed by two 0.7-m deep wetlands were constructed at the Reevesdale Mine. During the first year of operation, monthly data at the inflow, outflow and intermediate points within the treatment system were collected (April 2006-2007). The inflow to the treatment system ranged from 6.8 to 27.4 L/s, with median pH of 4.7, net acidity of 9.1 mg/L CaCO3, and concentrations of dissolved Al, Fe and Mn of 1.0, 1.9 and 0.89 mg/L, respectively. The corresponding effluent from the OLD had computed void-volume retention times of 4.5-18 h, with median pH of 6.6, net acidity of -93.2 mg/L CaCO3, and concentrations of dissolved Al, Fe and Mn of <0.1, 0.08 and 0.52 mg/L, respectively. The wetlands below the OLD were effective for retaining metal-rich solids flushed at monthly or more frequent intervals from the OLD, but otherwise had little effect on the effluent quality. During the first year of operation, approximately 43 metric tons of limestone were dissolved and 2 metric tons of Al, Fe and Mn were precipitated within the OLD. However, because of the accumulation of these metals within the OLD and possibly other debris from the mine, the effectiveness of the treatment system declined. Despite the installation of a flush-pipe network at the base of the OLD to remove precipitated solids, the limestone bed clogged near the inflow. Consequently, a large fraction of the AMD bypassed the treatment system. To promote flow through the OLD, the flush pipes were open continuously during the last 4 months of the study; however, this effluent was only partially treated because short-circuiting through the pipes decreased contact between the effluent and limestone. A reconfiguration of the flow path through the limestone bed from horizontal to vertical upward could increase the limestone surface area exposed to the metal-laden influent, increase the cross-sectional area perpendicular to flow, decrease the flow path for solids removal, and, consequently, decrease potential for clogging.

A Conceptual Hydrogeologic Model of the Vicinity of DUSEL Homestake

NASA Astrophysics Data System (ADS)

Murdoch, L. C.; Germanovich, L. N.; Boutt, D. F.; Kieft, T. L.; Wang, H. F.; Onstott, T. C.

2009-12-01

The Deep Underground Science and Engineering Laboratory (DUSEL) is a research facility planned to occupy the workings of the former Homestake gold mine in the northern Black Hills, South Dakota. The hydrogeology was of minor importance to locating and recovering gold ore, so it was overlooked during mining and is relatively unknown. This knowledge gap hinders planning of the Deep EcoHydrology Experiment at DUSEL and motivated the work described here. The conceptual hydrogeologic model is characterized by permeability that is assumed to be anisotropic and controlled by regional foliation, which strikes approximately N20W and dips steeply to the NE. Permeability is on the order of 0.1 mD in fresh rock, but increases to roughly 100 mD at shallow depths. The permeability distribution is assumed to result from unloading of the foliated rock, and a simple model of stress-dependence explains the permeability distribution and suggests that the more permeable zone is on the order of ~100 m thick. A stream hydrograph from Whitetail Creek (station 06436156) was analyzed to estimate recharge flux and the result indicates an average value of approximately 5 x 10-9 m/s. A numerical model of the vicinity of the mine was developed by representing the mine workings as a dual- porosity inclusion embedded in a single-porosity, anisotropic material. The extent of the dual-porosity medium was advanced downward based on the mining records and the hydraulic head within the material representing the mine workings was adjusted to represent filling and draining of the workings. The results suggest that the groundwater is characterized by a shallow flow system of distributed recharge that mostly discharges to nearby streams. The mine itself acts like a large sink that moves downward and to the southeast during mining, and then is controlled by variations in pumping rate once the mine reaches its greatest depth. The deep flow system consists of (i) a zone of relatively rapid flow from the ground surface to the mine workings overlying the southern part of the mine, and (ii) a much larger ellipsoidal zone extending up to several km from the workings where water has been removed from storage. Maximum downward fluxes in the deep system are less than the recharge rate because flow occurs at unit head gradient and the permeability of the rock is relatively low (~0.1 mD). This explains why dewatering has negligible impact on overlying streams and suggests that the regional water table remains within the shallow flow system. The results also indicate that water on the southern side of the mine is probably quite young (<~1 yr) and influenced by recent recharge, whereas water on the north side is much older and affected by removal from storage in deep pore space. The observed dewatering rate at the mine can be explained without requiring additional inflow from a large open pit or other surficial workings.

Effects of coal-mine discharges on the quality of the Stonycreek River and its tributaries, Somerset and Cambria counties, Pennsylvania

USGS Publications Warehouse

Williams, Donald R.; Sams, James I.; Mulkerrin, Mary E.

1996-01-01

This report describes the results of a study by the U.S. Geological Survey, done in cooperation with the Somerset Conservation District, to locate and sample abandoned coal-mine discharges in the Stonycreek River Basin, to prioritize the mine discharges for remediation, and to determine the effects of the mine discharges on water quality of the Stonycreek River and its major tributaries. From October 1991 through November 1994, 270 abandoned coal-mine discharges were located and sampled. Discharges from 193 mines exceeded U.S. Environmental Protection Agency effluent standards for pH, discharges from 122 mines exceeded effluent standards for total-iron concentration, and discharges from 141 mines exceeded effluent standards for total-manganese concentration. Discharges from 94 mines exceeded effluent standards for all three constituents. Only 40 mine discharges met effluent standards for pH and concentrations of total iron and total manganese.A prioritization index (PI) was developed to rank the mine discharges with respect to their loading capacity on the receiving stream. The PI lists the most severe mine discharges in a descending order for the Stonycreek River Basin and for subbasins that include the Shade Creek, Paint Creek, Wells Creek, Quemahoning Creek, Oven Run, and Pokeytown Run Basins.Passive-treatment systems that include aerobic wetlands, compost wetlands, and anoxic limestone drains (ALD's) are planned to remediate the abandoned mine discharges. The successive alkalinity-producing-system treatment combines ALD technology with the sulfate reduction mechanism of the compost wetland to effectively remediate mine discharge. The water quality and flow of each mine discharge will determine which treatment system or combination of treatment systems would be necessary for remediation.A network of 37 surface-water sampling sites was established to determine stream-water quality during base flow. A series of illustrations show how water quality in the mainstem deteriorates downstream because of inflows from tributaries affected by acidic mine discharges. From the upstream mainstem site (site 801) to the outflow mainstem site (site 805), pH decreased from 6.8 to 4.2, alkalinity was completely depleted by inflow acidities, and total-iron discharges increased from 30 to 684 pounds per day. Total-manganese and total-sulfate discharges increased because neither constituent precipitates readily. Also, discharges of manganese and sulfate entering the mainstem from tributary streams have a cumulative effect.Oven Run and Pokeytown Run are two small tributary streams significantly affected by acidic mine drainage (AMD) that flow into the Stonycreek River near the town of Hooversville. The Pokeytown Run inflow is about 0.5 mile downstream from the Oven Run inflow. These two streams are the first major source of AMD flowing into the Stonycreek River. Data collected on the Stonycreek River above the Oven Run inflow and below the Pokeytown Run inflow show a decrease in pH from 7.6 to 5.1, a decrease in alkalinity concentration from 42 to 2 milligrams per liter, an increase in total sulfate discharge from 18 to 41 tons per day, and an increase in total iron discharge from 29 to 1,770 pounds per day. Data collected at three mainstem sites on the Stonycreek River below Oven Run and Pokeytown Run show a progressive deterioration in river water quality from AMD.Shade Creek and Paint Creek are other tributary streams to the Stonycreek River that have a significant negative effect on water quality of the Stonycreek River. One third of the abandoned-mine discharges sampled were in the Shade Creek and Paint Creek Basins.

Examining microbial community response to a strong chemical gradient: the effects of surface coal mining on stream bacteria

NASA Astrophysics Data System (ADS)

Bier, R.; Lindberg, T. T.; Wang, S.; Ellis, J. C.; Di Giulio, R. T.; Bernhardt, E. S.

2012-12-01

Surface coal mining is the dominant form of land cover change in northern and central Appalachia. In this process, shallow coal seams are exposed by removing overlying rock with explosives. The resulting fragmented carbonate rock and coal residues are disposed of in stream valleys. These valley fills generate alkaline mine drainage (AlkMD), dramatically increasing alkalinity, ionic strength, substrate supply (esp. SO42-), and trace element (Mn, Li, Se, U) concentrations in downstream rivers as well as significant losses of sensitive fish and macroinvertebrate species. In prior work within the Mud River, which drains the largest surface mine complex in Appalachia, we found that concentrations of AlkMD increase proportionally with the extent of upstream mining. Here we ask "How do stream microbial communities change along this strong chemical gradient?" We collected surface water and benthic biofilms from 25 stream reaches throughout the Mud River spanning the full range of surface mining impacts, with 0-96% of the contributing watershed area converted to surface coal mines. Microbial communities were collected from biofilms grown on a common substrate (red maple veneers) that were incubated in each stream reach for four months prior to collection in April, 2011. 16S rRNA genes from microbial communities at each study site were examined using 454 sequencing and compared with a generalized UniFrac distance matrix (674 sequence eveness) that was used in statistical analyses. Water chemistry at the sites was sampled monthly from July 2010 to December 2010 and again in April 2011. In April, surface water concentrations of SO42-, Ca2+, Mg2+, and Se2- increased linearly with the extent of upstream mining (all regressions R2 >0.43; p<0.004), with the resulting gradient in ionic strength extending from low conductivity (average 83 μS cm-1 S.E. 27.4) in unmined streams (n=6) to as high as 899 μS cm-1 in the mainstem and 1889 μS cm-1 immediately below the Connelly Branch valley fill. Across this gradient, we found that microbial community composition varied significantly between sites receiving mine drainage and those that were unexposed (NMDS ordination R2 =0.86; PERMANOVA; p=0.029). Bacterial diversity (OTU richness defined at 3% sequence difference) peaked at intermediate conductivities (600 μS cm-1). Environmental data that correlated significantly with the ordination axes were a variety of surface water ions characteristic of AlkMD (SO42-, Mg2+, Sr2+, Se2-, and U) as well as stream DOC concentrations (p < 0.001).

Integrated approach to assess the environmental impact of mining activities: estimation of the spatial distribution of soil contamination (Panasqueira mining area, Central Portugal).

PubMed

Candeias, Carla; Ávila, Paula F; Ferreira da Silva, Eduardo; Teixeira, João Paulo

2015-03-01

Through the years, mining and beneficiation processes in Panasqueira Sn-W mine (Central Portugal) produced large amounts of As-rich mine wastes laid up in huge tailings and open-air impoundments (Barroca Grande and Rio tailings) that are the main source of pollution in the surrounding area once they are exposed to the weathering conditions leading to the formation of acid mine drainage (AMD) and consequently to the contamination of the surrounding environments, particularly soils. The active mine started the exploration during the nineteenth century. This study aims to look at the extension of the soil pollution due to mining activities and tailing erosion by combining data on the degree of soil contamination that allows a better understanding of the dynamics inherent to leaching, transport, and accumulation of some potential toxic elements in soil and their environmental relevance. Soil samples were collected in the surrounding soils of the mine, were digested in aqua regia, and were analyzed for 36 elements by inductively coupled plasma mass spectrometry (ICP-MS). Selected results are that (a) an association of elements like Ag, As, Bi, Cd, Cu, W, and Zn strongly correlated and controlled by the local sulfide mineralization geochemical signature was revealed; (b) the global area discloses significant concentrations of As, Bi, Cd, and W linked to the exchangeable and acid-soluble bearing phases; and (c) wind promotes the mechanical dispersion of the rejected materials, from the milled waste rocks and the mineral processing plant, with subsequent deposition on soils and waters. Arsenic- and sulfide-related heavy metals (such as Cu and Cd) are associated to the fine materials that are transported in suspension by surface waters or associated to the acidic waters, draining these sites and contaminating the local soils. Part of this fraction, especially for As, Cd, and Cu, is temporally retained in solid phases by precipitation of soluble secondary minerals (through the precipitation of hydrated metal sulfates) in warm, dry periods, but such minerals are easily dissolved during rainy periods. Climate is an important instability factor, and the hot and dry summers and cold, rainy, and windy winters in this region are physical phenomena that enhance the good receptivity of these soils to retain some of the metals present in the primary and also the secondary mineralogy. Considering the obtained results from both the sequential chemical extraction and the environmental risk assessment according to the risk assessment code, Ag, Cd, Cu, and Zn are classified with very high risk while As is classified with medium risk.

The occurrence and distribution of selected trace elements in the upper Rio Grande and tributaries in Colorado and Northern New Mexico

USGS Publications Warehouse

Taylor, Howard E.; Antweiler, Ronald C.; Roth, D.A.; Brinton, T.I.; Peart, D.B.; Healy, D.F.

2001-01-01

Two sampling trips were undertaken in 1994 to determine the distribution of trace elements in the Upper Rio Grande and several of its tributaries. Water discharges decreased in the main stem of the Rio Grande from June to September, whereas dissolved concentrations of trace elements generally increased. This is attributed to dilution of base flow from snowmelt runoff in the June samples. Of the three major mining districts (Creede, Summitville, and Red River) in the Upper Rio Grande drainage basin, only the Creede District appears to impact the Rio Grande in a significant manner, with both waters and sediments having elevated concentrations of some trace elements considerably downriver. For example, dissolved zinc concentrations upriver of Willow Creek, which primarily drains the Creede District, were about 2-3 μg/L; immediately downstream of the Willow Creek confluence, concentrations were above 20 μg/L; and elevated concentrations occurred in the Rio Grande for the next 100 km. The Red River District does not significantly impact the Upper Rio Grande for most trace elements. Because of current water management practices, it is difficult to assess the impact of the Summitville District on the Upper Rio Grande. There are, however, large increases in many dissolved trace element concentrations as the Rio Grande passes through the San Luis Valley, coincident with elevated concentrations of those same trace elements in tributaries. Among these elements are As, B, Cr, Li, Mn, Mo, Ni, Sr, U, and V. None of the trace elements exceeded U.S. EPA primary drinking water standards in either survey, with the exception of cadmium in Willow Creek. Secondary drinking water standards were frequently violated, especially in tributaries draining areas where mining has occurred. Dissolved zinc (in Willow Creek in both June and September) was the only element that exceeded the EPA Water Quality Criteria for aquatic life of 120 μg/L.

Battlefield scrotal trauma: how should it be managed in a deployed military hospital?

PubMed

Williams, R J; Fries, C A; Midwinter, M; Lambert, A W

2013-09-01

There is little documented advice on the management of scrotal trauma sustained in combat. This paper reviews this injury, its present surgical management and makes recommendations for the future. All UK forces sustaining scrotal injuries between 2003 and 2009, in Iraq and Afghanistan, initially treated at a Role 2 (enhanced) or Role 3 deployed military surgical facility were identified from the Joint Theatre Trauma Registry. The cause and extent of the injury, in addition to the surgical management, are reported. Twenty-seven patients sustained trauma to their scrotum; improvised explosive device (IED) (n=21), mine (n=3), rocket propeller grenade (RPG) (n=2), mortar round (n=1). Of those injured by an IED, eleven had traumatic orchidectomies, of which 4 were bilateral, one received fragmentation wounds to the scrotum with a testicular injury that was salvaged and there were six scrotal fragmentation wounds not associated with a testicular injury. Scrotal exploration was performed with testicular salvage in all cases involving mortar, RPG or mines. For all aetiologies the scrotum was debrided with primary closure over a drain (n=7), debridement and subsequent delayed primary closure (DPC) (n=4) or healing by secondary intension (n=6). Skin grafts were applied in two cases of traumatic bilateral orchidectomy. To date there have been two cases of delayed orchidectomy; chronic pain and delayed presentation of a disrupted testis. All reported patients survived. The established principles of debridement should be the mainstay of treatment. Testicular ischaemia, a consequence of cord transaction, necessitates orchidectomy. Salvage of the disrupted testis, with debridement and closure of the tunica rather than orchidectomy, should be performed whenever possible, particularly when there is significant bilateral testicular injury. Scrotal wounds can be treated by closure over a drain, DPC or healing by secondary intention. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hydrogeochemical and stream sediment detailed geochemical survey for Edgemont, South Dakota; Wyoming

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

Butz, T.R.; Dean, N.E.; Bard, C.S.

1980-05-31

Results of the Edgemont detailed geochemical survey are reported. Field and laboratory data are presented for 109 groundwater and 419 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are given. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwaters containing greater than or equal to 7.35 ppB uranium are present in scattered clusters throughout the area sampled. Most of these groundwaters are from wells drilled where the Inyan Kara Group is exposed at themore » surface. The exceptions are a group of samples in the northwestern part of the area sampled and south of the Dewey Terrace. These groundwaters are also produced from the Inyan Kara Group where it is overlain by the Graneros Group and alluvium. The high uranium groundwaters along and to the south of the terrace are characterized by high molybdenum, uranium/specific conductance, and uranium/sulfate values. Many of the groundwaters sampled along the outcrop of the Inyan Kara Group are near uranium mines. Groundwaters have high amounts of uranium and molybdenum. Samples taken downdip are sulfide waters with low values of uranium and high values of arsenic, molybdenum, selenium, and vanadium. Stream sediments containing greater than or equal to 5.50 ppM soluble uranium are concentrated in basins draining the Graneros and Inyan Kara Groups. These values are associated with high values for arsenic, selenium, and vanadium in samples from both groups. Anomalous values for these elements in the Graneros Group may be caused by bentonite beds contained in the rock units. As shown on the geochemical distribution plot, high uranium values that are located in the Inyan Kara Group are almost exclusively draining open-pit uranium mines.« less

Characterizing Ground-Water Flow Paths in High-Altitude Fractured Rock Settings Impacted by Mining Activities

NASA Astrophysics Data System (ADS)

Wireman, M.; Williams, D.

2003-12-01

The Rocky Mountains of the western USA have tens of thousands of abandoned, inactive and active precious-metal(gold,silver,copper)mine sites. Most of these sites occur in fractured rock hydrogeologic settings. Mining activities often resulted in mobilization and transport of associated heavy metals (zinc,cadmium,lead) which pose a significant threat to aquatic communities in mountain streams.Transport of heavy metals from mine related sources (waste rock piles,tailings impoudments,underground workings, mine pits)can occur along numerous hydrological pathways including complex fracture controlled ground-water pathways. Since 1991, the United States Environmental Protection Agency, the Colorado Division of Minerals and Geology and the University of Colorado (INSTAAR)have been conducting applied hydrologic research at the Mary Murphy underground mine. The mine is in the Chalk Creek mining district which is located on the southwestern flanks of the Mount Princeton Batholith, a Tertiary age intrusive comprised primarily of quartz monzonite.The Mount Princeton batholith comprises a large portion of the southern part of the Collegiate Range west of Buena Vista in Chaffee County, CO. Chalk Creek and its 14 tributaries drain about 24,900 hectares of the eastern slopes of the Range including the mining district. Within the mining district, ground-water flow is controlled by the distribution, orientation and permeability of discontinuities within the bedrock. Important discontinuities include faults, joints and weathered zones. Local and intermediate flow systems are perturbed by extensive underground excavations associated with mining (adits, shafts, stopes, drifts,, etc.). During the past 12 years numerous hydrological investigations have been completed. The investigations have been focused on developing tools for characterizing ground-water flow and contaminant transport in the vicinity of hard-rock mines in fractured-rock settings. In addition, the results from these investigations have been used to develop a sound conceptual model of ground-water flow and transport of heavy metals from the mine workings to Chalk Creek. Ground-water tracing techniques (using organic, fluorescent dyes) have been successfully used to delineate ground-water flow paths. Surface-water tracing techniques have been used to acquire very accurate stream flow measuements and to identify ground-water inflow zones to streams. Stable (O18/D)and radioactive (tritium,sulphur 35) isotope anlysis of waters flowing into and out of underground workings have proved useful for conducting end member mixing analysis to determine which inflows and outflows are most significant with respect to metals loading. Hydrogeologic mapping, inverse geochemical modeling (using MINTEQAK code)and helium 3 analysis of ground water have also proven to useful tools. These tools, used in combination have provided multiple lines of evidence regarding the nature, timing and magnitude of ground-water inflow into underground mine workings and the distribution and types of hydrologic pathways that transport metals from the underground workings to Chalk Creek. This paper presents the results of some of the more important hydrologic investigations completed at the site and a conceptual model of ground-water flow in fractured rock settings that have been impacted by underground mining activites.

Preliminary report on mercury geochemistry of placer gold dredge tailings, sediments, bedrock, and waters in the Clear Creek restoration area, Shasta County, California

USGS Publications Warehouse

Ashley, Roger P.; Rytuba, James J.; Rogers, Ronald; Kotlyar, Boris B.; Lawler, David

2002-01-01

Clear Creek, one of the major tributaries of the upper Sacramento River, drains the eastern Trinity Mountains. Alluvial plain and terrace gravels of lower Clear Creek, at the northwest edge of the Sacramento Valley, contain placer gold that has been mined since the Gold Rush by various methods including dredging. In addition, from the 1950s to the 1980s aggregate-mining operations removed gravel from the lower Clear Creek flood plain. Since Clear Creek is an important stream for salmon production, a habitat restoration program is underway to repair damage from mining and improve conditions for spawning. This program includes using dredge tailings to fill in gravel pits in the flood plain, raising the concern that mercury lost to these tailings in the gold recovery process may be released and become available to biota. The purposes of our study are to determine concentrations and speciation of mercury in sediments, tailings, and water in the lower Clear Creek area, and to determine its mobility. Mercury concentrations in bedrock and unmined gravels both within and above the mined area are low, and are taken to represent background concentrations. Bulk mercury values in flood-plain sediments and dry tailings are elevated to several times these background concentrations. Mercury in sediments and tailings is associated with fine size fractions. Although methylmercury levels are generally low in sediments, shallow ponds in the flood plain may have above-normal methylation potential. Stream waters in the area show low mercury and methylmercury levels. Ponds with elevated methylmercury in sediments have more methylmercury in their waters as well. One seep in the area is highly saline, and enriched in mercury, lithium, and boron, similar to connate waters that are expelled along thrust faults to the south on the west side of the Sacramento Valley. This occurrence suggests that mercury in waters may at least in part be from sources other than placer mining.

The use of fluoride as a natural tracer in water and the relationship to geological features: Examples from the Animas River Watershed, San Juan Mountains, Silverton, Colorado

USGS Publications Warehouse

Bove, D.J.; Walton-Day, K.; Kimball, B.A.

2009-01-01

Investigations within the Silverton caldera, in southwestern Colorado, used a combination of traditional geological mapping, alteration-assemblage mapping, and aqueous geochemical sampling that showed a relationship between geological and hydrologic features that may be used to better understand the provenance and evolution of the water. Veins containing fluorite, huebnerite, and elevated molybdenum concentrations are temporally and perhaps genetically associated with the emplacement of high-silica rhyolite intrusions. Both the rhyolites and the fluorite-bearing veins produce waters containing elevated concentrations of F-, K and Be. The identification of water samples with elevated F/Cl molar ratios (> 10) has also aided in the location of water draining F-rich sources, even after these waters have been diluted substantially. These unique aqueous geochemical signatures can be used to relate water chemistry to key geological features and mineralized source areas. Two examples that illustrate this relationship are: (1) surface-water samples containing elevated F-concentrations (> 1.8 mg/l) that closely bracket the extent of several small high-silica rhyolite intrusions; and (2) water samples containing elevated concentrations of F-(> 1.8 mg/ l) that spatially relate to mines or areas that contain late-stage fluorite/huebnerite veins. In two additional cases, the existence of high F-concentrations in water can be used to: (1) infer interaction of the water with mine waste derived from systems known to contain the fluorite/huebnerite association; and (2) relate changes in water quality over time at a high elevation mine tunnel to plugging of a lower elevation mine tunnel and the subsequent rise of the water table into mineralized areas containing fluorite/huebnerite veining. Thus, the unique geochemical signature of the water produced from fluorite veins indicates the location of high-silica rhyolites, mines, and mine waste containing the veins. Existence of high F-concentrations along with K and Be in water in combination with other geological evidence may be used to better understand the provenance of the water. ?? 2009 AAG/Geological Society of London.

Infiltration and soil erosion modelling on Lausatian post mine sites

NASA Astrophysics Data System (ADS)

Kunth, Franziska; Schmidt, Jürgen

2013-04-01

Land management of reclaimed lignite mine sites requires long-term and safe structuring of recultivation areas. Erosion by water leads to explicit soil losses, especially on heavily endangered water repellent and non-vegetated soil surfaces. Beyond that, weathering of pyrite-containing lignite burden dumps causes sulfuric acid-formation, and hence the acidification of groundwater, seepage water and surface waters. Pyrite containing sediment is detached by precipitation and transported into worked-out open cuts by draining runoff. In addition to ground water influence, erosion processes are therefore involved in acidification of surface waters. A model-based approach for the conservation of man-made slopes of post mining sites is the objective of this ongoing study. The study shall be completed by modeling of the effectiveness of different mine site recultivation scenarios. Erosion risks on man-made slopes in recultivation areas should be determined by applying the physical, raster- and event based computer model EROSION 2D/3D (Schmidt, 1991, 1992; v. Werner, 1995). The widely used erosion model is able to predict runoff as well as detachment, transport and deposition of sediments. Lignite burden dumps contain hydrophobic substances that cover soil particles. Consequently, these soils show strong water repellency, which influences the processes of infiltration and soil erosion on non-vegetated, coal containing dump soils. The influence of water repellency had to be implemented into EROSION 2D/3D. Required input data for soil erosion modelling (e.g. physical soil parameters, infiltration rates, calibration factors, etc.) were gained by soil sampling and rainfall experiments on non-vegetated as well as recultivated reclaimed mine sites in the Lusatia lignite mining region (southeast of Berlin, Germany). The measured infiltration rates on the non-vegetated water repellent sites were extremely low. Therefore, a newly developed water repellency-factor was applied to depict infiltration and erosion processes on water repellent dump soils. For infiltration modelling with EROSION 2D calibration factors (e.g. water repellency factor, skin-factor, etc.) were determined in different steps by calibrating computer modelled infiltration, respectively volume rate of flow to the measured data.

Hydrogeology, groundwater flow, and groundwater quality of an abandoned underground coal-mine aquifer, Elkhorn Area, West Virginia

USGS Publications Warehouse

Kozar, Mark D.; McCoy, Kurt J.; Britton, James Q.; Blake, B.M.

2017-01-01

The Pocahontas No. 3 coal seam in southern West Virginia has been extensively mined by underground methods since the 1880’s. An extensive network of abandoned mine entries in the Pocahontas No. 3 has since filled with good-quality water, which is pumped from wells or springs discharging from mine portals (adits), and used as a source of water for public supplies. This report presents results of a three-year investigation of the geology, hydrology, geochemistry, and groundwater flow processes within abandoned underground coal mines used as a source of water for public supply in the Elkhorn area, McDowell County, West Virginia. This study focused on large (> 500 gallon per minute) discharges from the abandoned mines used as public supplies near Elkhorn, West Virginia. Median recharge calculated from base-flow recession of streamflow at Johns Knob Branch and 12 other streamflow gaging stations in McDowell County was 9.1 inches per year. Using drainage area versus mean streamflow relationships from mined and unmined watersheds in McDowell County, the subsurface area along dip of the Pocahontas No. 3 coal-mine aquifer contributing flow to the Turkey Gap mine discharge was determined to be 7.62 square miles (mi2), almost 10 times larger than the 0.81 mi2 surface watershed. Results of this investigation indicate that groundwater flows down dip beneath surface drainage divides from areas up to six miles east in the adjacent Bluestone River watershed. A conceptual model was developed that consisted of a stacked sequence of perched aquifers, controlled by stress-relief and subsidence fractures, overlying a highly permeable abandoned underground coal-mine aquifer, capable of substantial interbasin transfer of water. Groundwater-flow directions are controlled by the dip of the Pocahontas No. 3 coal seam, the geometry of abandoned mine workings, and location of unmined barriers within that seam, rather than surface topography. Seven boreholes were drilled to intersect abandoned mine workings in the Pocahontas No. 3 coal seam and underlying strata in various structural settings of the Turkey Gap and adjacent down-dip mines. Geophysical logging and aquifer testing were conducted on the boreholes to locate the coal- mine aquifers, characterize fracture geometry, and define permeable zones within strata overlying and underlying the Pocahontas No. 3 coal-mine aquifer. Water levels were measured monthly in the wells and showed a relatively static phreatic zone within subsided strata a few feet above the top of or within the Pocahontas No. 3 coal-mine aquifer (PC3MA). A groundwater-flow model was developed to verify and refine the conceptual understanding of groundwater flow and to develop groundwater budgets for the study area. The model consisted of four layers to represent overburden strata, the Pocahontas No. 3 coal-mine aquifer, underlying fractured rock, and fractured rock below regional drainage. Simulation of flow in the flooded abandoned mine entries using highly conductive layers or zones within the model, was unable to realistically simulate interbasin transfer of water. Therefore it was necessary to represent the coal-mine aquifer as an internal boundary condition rather than a contrast in aquifer properties. By representing the coal-mine aquifer with a series of drain nodes and optimizing input parameters with parameter estimation software, model errors were reduced dramatically and discharges for Elkhorn Creek, Johns Knob Branch, and other tributaries were more accurately simulated. Flow in the Elkhorn Creek and Johns Knob Branch watersheds is dependent on interbasin transfer of water, primarily from up dip areas of abandoned mine workings in the Pocahontas No. 3 coal-mine aquifer within the Bluestone River watershed to the east. For the 38th, 70th, and 87th percentile flow duration of streams in the region, mean measured groundwater discharge was estimated to be 1.30, 0.47, and 0.39 cubic feet per square mile (ft3/s/mi2

Hydrology and water-quality monitoring considerations, Jackpile uranium mine, northwestern New Mexico

USGS Publications Warehouse

Zehner, H.H.

1985-01-01

The Jackpile Uranium Mine, which is on the Pueblo of Laguna in northwestern New Mexico, was operated from 1953 to 1980. The mine and facilities have affected 3,141 acres of land, and about 2,656 acres were yet to be reclaimed by late 1980. The intended use of the restored land is stock grazing. Fractured Dakota Sandstone and Mancos Shale of Cretaceous age overlie the Jackpile sandstone and a 200-ft-thick tight mudstone unit of the Brushy Basin Member underlies the Jackpile. The hydraulic conductivity of the Jackpile sandstone probably is about 0.3 ft/day. The small storage coefficients determined from three aquifer tests indicate that the Jackpile sandstone is a confined hydrologic system throughout much of the mine area. Sediment from the Rio Paguate has nearly filled the Paguate Reservoir near Laguna since its construction in 1940. The mean concentrations of uranium, Ra-226, and other trace elements generally were less than permissible limits established in national drinking water regulations or New Mexico State groundwater regulations. No individual surface water samples collected upstream from the mine contained concentrations of Ra-226 in excess of the permissible limits. Ra-226 concentrations in many individual samples collected from the Rio Paguate from near the mouth of the Rio Moquino to the sampling sites along the downstream reach of the Rio Paguate, however, exceeded the recommended permissible concentration of Ra-226 for public drinking water supplies. Concentrations in surface water apparently are changed by groundwater inflow near the confluence of the two streams. The altitude of the water tables in the backfill of the pits will be controlled partly by the water level in the Rio Paguate. Other factors controlling the altitudes of the water tables are the recharge rate to the backfill and the hydraulic conductivities of the backfill, alluvium, Jackpile sandstone, and mudstone unit of the Brushy Basin Member. After reclamation, most of the shallow groundwater probably will discharge to the natural stream channels draining the mine area. Groundwater quality may be monitored as: (1) ' Limited monitoring, ' in which only the change in water quality is determined as the groundwater flows from the mine; or (2) ' thorough monitoring, ' in which specific sources of possible contaminants are described. (Author 's Abstract)

Experimental research on coalbed gas drainage effect and economy of long directional borehole in roof

NASA Astrophysics Data System (ADS)

Yang, Huiming; Hu, Liangping

2017-05-01

In order to study the coalbed gas drainage effect and economy of long directional roof borehole, 2 boreholes were laid out in Xinji No. 2 mine to analyze its gas drainage and investment costs comparing with high position roof borehole and high position roof roadway. The result indicates that the long directional roof borehole save investment by 44.8% and shorten the construction period by 30%, comparing with high position roof roadway for controlling gas in the working face. Investment slightly less and shorten the construction period by 47.5%, comparing with the roof high position borehole. Therefore, the method of the long directional roof borehole to drain coalbed gas in working face is the most cost-effective.

Effects of Abandoned Coal-Mine Drainage on Streamflow and Water Quality in the Mahanoy Creek Basin, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania, 2001

USGS Publications Warehouse

Cravotta,, Charles A.

2004-01-01

This report assesses the contaminant loading, effects to receiving streams, and possible remedial alternatives for abandoned mine drainage (AMD) within the Mahanoy Creek Basin in east-central Pennsylvania. The Mahanoy Creek Basin encompasses an area of 157 square miles (407 square kilometers) including approximately 42 square miles (109 square kilometers) underlain by the Western Middle Anthracite Field. As a result of more than 150 years of anthracite mining in the basin, ground water, surface water, and streambed sediments have been adversely affected. Leakage from streams to underground mines and elevated concentrations (above background levels) of acidity, metals, and sulfate in the AMD from flooded underground mines and (or) unreclaimed culm (waste rock) degrade the aquatic ecosystem and impair uses of the main stem of Mahanoy Creek from its headwaters to its mouth on the Susquehanna River. Various tributaries also are affected, including North Mahanoy Creek, Waste House Run, Shenandoah Creek, Zerbe Run, and two unnamed tributaries locally called Big Mine Run and Big Run. The Little Mahanoy Creek and Schwaben Creek are the only major tributaries not affected by mining. To assess the current hydrological and chemical characteristics of the AMD and its effect on receiving streams, and to identify possible remedial alternatives, the U.S. Geological Survey (USGS) began a study in 2001, in cooperation with the Pennsylvania Department of Environmental Protection and the Schuylkill Conservation District. Aquatic ecological surveys were conducted by the USGS at five stream sites during low base-flow conditions in October 2001. Twenty species of fish were identified in Schwaben Creek near Red Cross, which drains an unmined area of 22.7 square miles (58.8 square kilometers) in the lower part of the Mahanoy Creek Basin. In contrast, 14 species of fish were identified in Mahanoy Creek near its mouth at Kneass, below Schwaben Creek. The diversity and abundance of fish species in Mahanoy Creek decreased progressively upstream from 13 species at Gowen City to only 2 species each at Ashland and Girardville. White sucker (Catostomus commersoni), a pollution-tolerant species, was present at each of the surveyed reaches. The presence of fish at Girardville was unexpected because of the poor water quality and iron-encrusted streambed at this location. Generally, macroinvertebrate diversity and abundance at these sites were diminished compared to Schwaben Creek and other tributaries draining unmined basins, consistent with the observed quality of streamwater and streambed sediment. Data on the flow rate and chemistry for 35 AMD sources and 31 stream sites throughout the Mahanoy Creek Basin were collected by the USGS during high base-flow conditions in March 2001 and low base-flow conditions in August 2001. A majority of the base-flow streamwater samples met water-quality standards for pH (6.0 to 9.0); however, few samples downstream from AMD sources met criteria for acidity less than alkalinity (net alkalinity = 20 milligrams per liter as CaCO3) and concentrations of dissolved iron (0.3 milligram per liter) and total manganese (1.0 milligram per liter). Iron, aluminum, and various trace elements including cobalt, copper, lead, nickel, and zinc, were present in many streamwater samples at concentrations at which continuous exposure can not be tolerated by aquatic organisms without an unacceptable effect. Furthermore, concentrations of sulfate, iron, manganese, aluminum, and (or) beryllium in some samples exceeded drinking-water standards. Other trace elements, including antimony, arsenic, barium, cadmium, chromium, selenium, silver, and thallium, did not exceed water-quality criteria for protection of aquatic organisms or human health. Nevertheless, when considered together, concentrations of iron, manganese, arsenic, cadmium, chromium, copper, lead, nickel, and zinc in a majority of the streambed sediment samples from Mahanoy Creek and

Quantifying biomineralization of zinc in the Rio Naracauli (Sardinia, Italy), using a tracer injection and synoptic sampling

USGS Publications Warehouse

De Giudici, Giovanni; Wanty, Richard B.; Podda, F.; Kimball, Briant A.; Verplanck, Philip L.; Lattanzi, P.; Cidu, R.; Medas, D.

2014-01-01

Streams draining mined areas throughout the world commonly have high concentrations of Zn. Because Zn is not easily removed from stream water and because it can be toxic to aquatic organisms, its presence is a persistent problem. The discovery of biomineralization of Zn-bearing solids in the mine drainage of Rio Naracauli, in Sardinia, Italy, provides insights into strategies for removing Zn and improving water quality in streams affected by mine drainage. Until now, the transport and attenuation of Zn has not been quantified in this stream setting. A continuous tracer injection experiment was conducted to quantify the biomineralization process and to identify the loading of constituents that causes a change from precipitation of hydrozincite [Zn5(CO3)2(OH)6] in the upstream reach to precipitation of a Zn-silicate phase downstream. Based on the mass-load calculations derived from the tracer experiment, about 1.2 kg/day of Zn is sequestered in hydrozincite. This biomineralization represents nearly 90% removal of Zn. Other elements such as Pb and Cd also are sequestered, either in the hydrozincite, or in a separate phase that forms simultaneously. In the lower 600 m of the stream, where the Zn-silicate forms, as much as 0.7 kg/day Zn are sequestered in this solid, but additions of Zn to the stream from groundwater discharge lead to an overall increase in load in that portion of the Rio Naracauli.

Preliminary hydrologic evaluation of the North Horn Mountain coal-resource area, Utah

USGS Publications Warehouse

Graham, M.J.; Tooley, John E.; Price, Don

1981-01-01

North Horn Mountain is part of a deeply dissected plateau in central Utah which is characterized by deep, narrow, steep-walled canyons with local relief of more than 1,000 feet. Geologic units exposed in the North Horn Mountain area range in age from Late Cretaceous to Holocene and contain two mineable seams of Cretaceous coal. The area is in the drainage basin of the San Rafael River, in the Colorado River Basin. Runoff from the mountain is ephemeral. This runoff to the San Rafael River is by way of Cottonwood and Perron Creeks and represents less than 10 percent of their average annual runoff. Probable peak discharges (100-year flood) for the ephemeral streams draining North Horn Mountain are estimated to range from 200 to 380 cubic feet per second.The chemical quality of surface water in the area is good. The water is generally of a calcium magnesium bicarbonate type with average dissolved solids less than 500 milligrams per liter. Annual sediment yield in most of the area ranges from 0.1 to 0.2 acre-foot per square mile but locally is as high as 1.0 acre-foot per square mile. Most of the sediment is eroded during cloudbursts.Most of the ground water above the coal on North Horn Mountain probably is in perched aquifers. These aquifers support the flow of small seeps and springs. In some areas, the regional water table appears to extend upward into the coal. The principal source of recharge is precipitation that probably moves to aquifers along faults, joints, or fractures. This movement is apparently quite rapid. The dissolved-solids concentrations of ground water in the North Horn Mountain area range from less than 500 to about 1,000 milligrams per liter.Coal mining on North Horn Mountain should have minor "effects on the quantity and quality of surface water. The maximum predicted decrease in the annual flow of Ferron and Cottonwood Creeks is less than U percent. The sediment loads of affected streams could be significantly increased if construction were to take place during the summer cloudburst season. Subsidence, which usually follows underground coal mining, could create rock fractures through which a perched aquifer might be drained, thus depleting the flow of seeps or springs fed by that aquifer. It is considered unlikely that the mining will adversely affect the chemical quality of the ground water.

Rare earth and trace element signatures for assessing an impact of rock mining and processing on the environment: Wiśniówka case study, south-central Poland.

PubMed

Migaszewski, Zdzisław M; Gałuszka, Agnieszka; Dołęgowska, Sabina

2016-12-01

A detailed hydrogeochemical study was performed in the Wiśniówka mining area (south-central Poland). This covered three acid pit bodies, historic tailings acid ponds, acid pools, and additionally two neighboring rivers. All these acid mine drainage (AMD) waters are characterized by the pH in the range of 1.7 (pools) to 3.5 (tailings ponds). The most interesting is the Podwiśniówka acid pit lake that shows a very low pH (2.2-2.5) and very high concentrations of SO 4 2- (2720-5460 mg/L), Fe (545-1140 mg/L), Al (86.2 mg/L), As (9603-24,883 μg/L), Co (1317-3458 μg/L), Cr (753-2047 μg/L), Cu (6307-18,879 μg/L), Ni (1168-3127 μg/L), and rare earth element (REE) (589-1341 μg/L). In addition, seeps that drain the Podwiśniówka mine tailings and partly aggregate piles form strong acid pools in the mining area. Along with these pools, in which As and REE contents reach 369,726 and 6288 μg/L, respectively, these waters are among the most distinctive As- and REE-rich AMD surface waters across the world. It is noteworthy that the Podwiśniówka acid pit lake and Wiśniówka Duża acid pit sump exhibit different element signatures and REE concentration patterns normalized to North American Composite Shale (NASC): the Podwiśniówka acid pit lake always shows a characteristic roof-shaped medium REE (MREE) profile with distinct enrichments in Gd, Eu, and Tb whereas the other one displays a step-shaped heavy REE (HREE) profile with positive Tb and Gd anomalies. The REE undergo fractionation during weathering and the subsequent leaching of dissolved and suspended fractions from rocks to acid water bodies where these and other elements are further fractionated by geochemical processes. This study shows that the individual REE have greater affinities for Mn, HREE for Fe and SO 4 2- , and only La and Ce for Al. This specific water geochemistry has enabled us to (i) pinpoint the location of AMD "hot spots" originated from quartzite mining and processing operations conducted by current and previous mining companies, (ii) predict the directions and effects of future strip mining for quartzites in the Wiśniówka Duża and Podwiśniówka open pits, and (iii) evaluate the potential impact of mining and processing effluents on the quality of rivers.

Tracing ancient hydrogeological fracture network age and compartmentalisation using noble gases

NASA Astrophysics Data System (ADS)

Warr, Oliver; Sherwood Lollar, Barbara; Fellowes, Jonathan; Sutcliffe, Chelsea N.; McDermott, Jill M.; Holland, Greg; Mabry, Jennifer C.; Ballentine, Christopher J.

2018-02-01

We show that fluid volumes residing within the Precambrian crystalline basement account for ca 30% of the total groundwater inventory of the Earth (> 30 million km3). The residence times and scientific importance of this groundwater are only now receiving attention with ancient fracture fluids identified in Canada and South Africa showing: (1) microbial life which has existed in isolation for millions of years; (2) significant hydrogen and hydrocarbon production via water-rock reactions; and (3) preserving noble gas components from the early atmosphere. Noble gas (He, Ne, Ar, Kr, Xe) abundance and isotopic compositions provide the primary evidence for fluid mean residence time (MRT). Here we extend the noble gas data from the Kidd Creek Mine in Timmins Ontario Canada, a volcanogenic massive sulfide (VMS) deposit formed at 2.7 Ga, in which fracture fluids with MRTs of 1.1-1.7 Ga were identified at 2.4 km depth (Holland et al., 2013); to fracture fluids at 2.9 km depth. We compare here the Kidd Creek Mine study with noble gas compositions determined in fracture fluids taken from two mines (Mine 1 & Mine 2) at 1.7 and 1.4 km depth below surface in the Sudbury Basin formed by a meteorite impact at 1.849 Ga. The 2.9 km samples at Kidd Creek Mine show the highest radiogenic isotopic ratios observed to date in free fluids (e.g. 21Ne/22Ne = 0.6 and 40Ar/36Ar = 102,000) and have MRTs of 1.0-2.2 Ga. In contrast, resampled 2.4 km fluids indicated a less ancient MRT (0.2-0.6 Ga) compared with the previous study (1.1-1.7 Ga). This is consistent with a change in the age distribution of fluids feeding the fractures as they drain, with a decreasing proportion of the most ancient end-member fluids. 129Xe/136Xe ratios for these fluids confirm that boreholes at 2.4 km versus 2.9 km are sourced from hydrogeologically distinct systems. In contrast, results for the Sudbury mines have MRTs of 0.2-0.6 and 0.2-0.9 Ga for Mines 1 and 2 respectively. While still old compared to almost all groundwaters reported in the literature to date, these younger residence times compared to Kidd Creek Mine are consistent with significant fracturing created by the impact event, facilitating more hydrogeologic connection and mixing of fluids in the basin. In all samples from both Kidd Creek Mine and Sudbury, a 124-128Xe excess is identified over modern air values. This is attributed to an early atmospheric xenon component, previously identified at Kidd Creek Mine but which has to date not been observed in fluids with a residence time as recent as 0.2-0.6 Ga. The temporal and spatial sampling at Kidd Creek Mine is also used to verify our proposed conceptual model which provides key constraints regarding distribution, volumes and residence times of fracture fluids on the smaller, regional, scale.

Chemical Data for Rock, Sediment, Biological, Precipitate, and Water Samples from Abandoned Copper Mines in Prince William Sound, Alaska

USGS Publications Warehouse

Koski, Randolph A.; Munk, LeeAnn

2007-01-01

In the early 20th century, approximately 6 million metric tons of copper ore were mined from numerous deposits located along the shorelines of fjords and islands in Prince William Sound, Alaska. At the Beatson, Ellamar, and Threeman mine sites (fig. 1), rocks containing Fe, Cu, Zn, and Pb sulfide minerals are exposed to chemical weathering in abandoned mine workings and remnant waste piles that extend into the littoral zone. Field investigations in 2003 and 2005 as well as analytical data for rock, sediment, precipitate, water, and biological samples reveal that the oxidation of sulfides at these sites is resulting in the generation of acid mine drainage and the transport of metals into the marine environment (Koski and others, 2008; Stillings and others, 2008). At the Ellamar and Threeman sites, plumes of acidic and metal-enriched water are flowing through beach gravels into the shallow offshore environment. Interstitial water samples collected from beach sediment at Ellamar have low pH levels (to ~3) and high concentrations of metals including iron, copper, zinc, cobalt, lead, and mercury. The abundant precipitation of the iron sulfate mineral jarosite in the Ellamar gravels also signifies a low-pH environment. At the Beatson mine site (the largest copper mine in the region) seeps containing iron-rich microbial precipitates drain into the intertidal zone below mine dumps (Foster and others, 2008). A stream flowing down to the shoreline from underground mine workings at Beatson has near-neutral pH, but elevated levels of zinc, copper, and lead (Stillings and others, 2008). Offshore sediment samples at Beatson are enriched in these metals. Preliminary chemical data for tissue from marine mussels collected near the Ellamar, Threeman, and Beatson sites reveal elevated levels of copper, zinc, and lead compared to tissue in mussels from other locations in Prince William Sound (Koski and others, 2008). Three papers presenting results of this ongoing investigation of sulfide oxidation in Prince William Sound are in press. Koski and others (2008) provide an overview of rock alteration, surface water chemistry, and the distribution of metals at the Ellamar, Threeman, and Beatson mine sites. Based on a 60-day, stream-discharge experiment at Beatson in 2005, Stillings and others (2008) analyze changes in water chemistry during storm events and the flux of metals to the shoreline. Foster and others (2008) investigate the biomass and diversity of microbial communities present in surface waters (streams, seeps, pore waters) using fatty acid methyl ester (FAMES) data and principal component analysis. The publications cited above contain a subset of the total chemical data for rock, sediment, biological, precipitate, and water samples collected from the three mine sites in 2003 and 2005. The purpose of this report is the presentation of complete chemical data sets for all samples collected during the two field periods of fieldwork. Data for a small number of samples collected at two other mines (Schlosser and Fidalgo, fig. 1), visited in 2003, are also included in the tables.

Chemical Data for Rock, Sediment, Biological, Precipitate, and Water Samples from Abandoned Copper Mines in Prince William Sound, Alaska

USGS Publications Warehouse

Koski, Randolph A.; Munk, LeeAnn

2007-01-01

Introduction In the early 20th century, approximately 6 million metric tons of copper ore were mined from numerous deposits located along the shorelines of fjords and islands in Prince William Sound, Alaska. At the Beatson, Ellamar, and Threeman mine sites (fig. 1), rocks containing Fe, Cu, Zn, and Pb sulfide minerals are exposed to chemical weathering in abandoned mine workings and remnant waste piles that extend into the littoral zone. Field investigations in 2003 and 2005 as well as analytical data for rock, sediment, precipitate, water, and biological samples reveal that the oxidation of sulfides at these sites is resulting in the generation of acid mine drainage and the transport of metals into the marine environment (Koski and others, 2008; Stillings and others, 2008). At the Ellamar and Threeman sites, plumes of acidic and metal-enriched water are flowing through beach gravels into the shallow offshore environment. Interstitial water samples collected from beach sediment at Ellamar have low pH levels (to ~3) and high concentrations of metals including iron, copper, zinc, cobalt, lead, and mercury. The abundant precipitation of the iron sulfate mineral jarosite in the Ellamar gravels also signifies a low-pH environment. At the Beatson mine site (the largest copper mine in the region) seeps containing iron-rich microbial precipitates drain into the intertidal zone below mine dumps (Foster and others, 2008). A stream flowing down to the shoreline from underground mine workings at Beatson has near-neutral pH, but elevated levels of zinc, copper, and lead (Stillings and others, 2008). Offshore sediment samples at Beatson are enriched in these metals. Preliminary chemical data for tissue from marine mussels collected near the Ellamar, Threeman, and Beatson sites reveal elevated levels of copper, zinc, and lead compared to tissue in mussels from other locations in Prince William Sound (Koski and others, 2008). Three papers presenting results of this ongoing investigation of sulfide oxidation in Prince William Sound are in press. Koski and others (2008) provide an overview of rock alteration, surface water chemistry, and the distribution of metals at the Ellamar, Threeman, and Beatson mine sites. Based on a 60-day, stream-discharge experiment at Beatson in 2005, Stillings and others (2008) analyze changes in water chemistry during storm events and the flux of metals to the shoreline. Foster and others (2008) investigate the biomass and diversity of microbial communities present in surface waters (streams, seeps, pore waters) using fatty acid methyl ester (FAMES) data and principal component analysis. The publications cited above contain a subset of the total chemical data for rock, sediment, biological, precipitate, and water samples collected from the three mine sites in 2003 and 2005. The purpose of this report is the presentation of complete chemical data sets for all samples collected during the two field periods of fieldwork. Data for a small number of samples collected at two other mines (Schlosser and Fidalgo, fig. 1), visited in 2003, are also included in the tables.

Concentrations of selected metals in Quaternary-age fluvial deposits along the lower Cheyenne and middle Belle Fourche Rivers, western South Dakota, 2009-10

USGS Publications Warehouse

Stamm, John F.; Hoogestraat, Galen K.

2012-01-01

The headwaters of the Cheyenne and Belle Fourche Rivers drain the Black Hills of South Dakota and Wyoming, an area that has been affected by mining and ore-milling operations since the discovery of gold in 1875. A tributary to the Belle Fourche River is Whitewood Creek, which drains the area of the Homestake Mine, a gold mine that operated from 1876 to 2001. Tailings discharged into Whitewood Creek contained arsenopyrite, an arsenic-rich variety of pyrite associated with gold ore, and mercury used as an amalgam during the gold-extraction process. Approximately 18 percent of the tailings that were discharged remain in fluvial deposits on the flood plain along Whitewood Creek, and approximately 25 percent remain in fluvial deposits on the flood plain along the Belle Fourche River, downstream from Whitewood Creek. In 1983, a 29-kilometer (18-mile) reach of Whitewood Creek and the adjacent flood plain was included in the U.S. Environmental Protection Agency's National Priority List of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, commonly referred to as a "Superfund site." Listing of this reach of Whitewood Creek was primarily in response to arsenic toxicity of fluvial deposits on the flood plain. Lands along the lower Cheyenne River were transferred to adjoining States and Tribes in response to the Water Resources Development Act (WRDA) of 1999. An amendment in 2000 to WRDA required a study of sediment contamination of the Cheyenne River. In response to the WRDA amendment, the U.S. Geological Survey completed field sampling of reference sites (not affected by mine-tailing disposal) along the lower Belle Fourche and lower Cheyenne Rivers. Reference sites were located on stream terraces that were elevated well above historical stream stages to ensure no contamination from historical mining activity. Sampling of potentially contaminated sites was performed on transects of the active flood plain and adjacent terraces that could potentially be inundated during high-flow events. Sampling began in 2009 and was completed in 2010. A total of 74 geochemical samples were collected from fluvial deposits at reference sites, and 473 samples were collected from potentially contaminated sites. Sediment samples collected were analyzed for 23 metals, including arsenic and mercury. Sequential replicate, split duplicate, and field quality-control samples were analyzed for quality assurance of data-collection methods. The metal concentrations in sediment samples and location information are presented in this report in electronic format (Microsoft Excel), along with non-parametric summary statistics of those data. Cross-sectional topography is graphed with arsenic and mercury concentrations on transects at the potentially contaminated sites. The mean arsenic concentration in reference sediment samples was 8 milligrams per kilogram (mg/kg), compared to 250, 650, and 76 mg/kg for potentially contaminated sediment samples at the surface of the middle Belle Fourche River site, the subsurface of the middle Belle Fourche River site, and the surface of the lower Cheyenne River site, respectively. The mean mercury concentration in reference sediment samples was 16 micrograms per kilogram (μg/kg), compared to 130, 370, and 71 μg/kg for potentially contaminated sediment samples at the surface of the middle Belle Fourche River site, the subsurface of the middle Belle Fourche River site, and the surface of the lower Cheyenne River site, respectively.

Randomized Controlled Trial to Reduce Bacterial Colonization of Surgical Drains After Breast and Axillary Operations

PubMed Central

Degnim, Amy C.; Scow, Jeffrey S.; Hoskin, Tanya L.; Miller, Joyce P.; Loprinzi, Margie; Boughey, Judy C.; Jakub, James W.; Throckmorton, Alyssa; Patel, Robin; Baddour, Larry M.

2014-01-01

Objective To determine if bacterial colonization of drains can be reduced by local antiseptic interventions. Summary Background Drains are a potential source of bacterial entry into surgical wounds and may contribute to surgical site infection (SSI) after breast surgery. Methods Following IRB approval, patients undergoing total mastectomy and/or axillary lymph node dissection were randomized to standard drain care (control) or drain antisepsis (treated). Standard drain care comprised twice daily cleansing with alcohol swabs. Antisepsis drain care included 1) a chlorhexidine disc at the drain exit site and 2) irrigation of the drain bulb twice daily with dilute sodium hypochlorite (Dakin’s) solution. Cultures results of drain fluid and tubing were compared between control and antisepsis groups. Results Overall, 100 patients with 125 drains completed the study with 48 patients (58 drains) in the control group and 52 patients (67 drains) in the antisepsis group. Cultures of drain bulb fluid at one week were positive (1+ or greater growth) in 66% (38/58) of control drains compared to 21% of antisepsis drains (14/67), (p=0.0001). Drain tubing cultures demonstrated >50 CFU in 19% (8/43) of control drains versus 0% (0/53) of treated drains (p=0.004). SSI was diagnosed in 6 patients (6%) - 5 patients in the control group and 1 patient in the antisepsis group (p=0.06). Conclusions Simple and inexpensive local antiseptic interventions with a chlorhexidine disc and hypochlorite solution reduce bacterial colonization of drains. Based on these data, further study of drain antisepsis and its potential impact on SSI rate is warranted. PMID:23518704

Evidence of Mercurial Contamination and Denundation Downstream of New Idria Mercury Mine, San Benito County, California

NASA Astrophysics Data System (ADS)

Letsinger, H. E.; Sharma, R. K.; Weinman, B.

2014-12-01

California's Central Valley water quality and soils are essential to the survival of the valley's communities and agriculture. Therefore, detection of possible contaminants within the valley streams and soils are paramount to the protection of this land and the people that depend upon it. Here we explore the impact of the contaminated stream beds near the New Idria Mercury Mine site, San Benito County, California. Previous work by Ganguli et al. (2000) has been done in this area to determine the mercury levels associated with the water that flows near the ghost town of New Idria. We performed geochemical analyses on the finer bed sediments from channels draining the area, as well as the coarser sediments taken from along the channel banks, to determine mercury transport downriver from the source. Using a novel application of tau, a mass transfer coefficient typically used in critical zone studies or soil production and weathering rates, we determine downstream weathering, accumulation, and transport of mercury. Our initial geochemical data showed higher tau values upstream as well as within the banks of the contaminated streambed and a greater accumulation of mercury near the pollution source (i.e., mine tailings, (τ ~ 103)). Tau results also show elevated mercurial levels existing downstream, with accumulations in mid- (τ ~ 102) and down-stream (τ ~ 10) reaches. Combining tau results with more traditional indices of chemical weathering (CIA) support consistent overall Hg-weathering processes with low levels of chemical weathering and higher dominance of coupled physical-anthropogenic weathering.

[Ecological vulnerability of coal mining area: a case study of Shengli Coalfield in Xilinguole of Inner Mongolia, China].

PubMed

Quan, Zhan-Jun; Li, Yuan; Li, Jun-Sheng; Han, Yu; Xiao, Neng-Wen; Fu, Meng-Di

2013-06-01

In this paper, an ecological vulnerability evaluation index system for the Shengli Coalfield in Xilinguole of Inner Mongolia was established, which included 16 factors in ecological sensitivity, natural and social pressure, and ecological recovery capacity, respectively. Based on the expert scoring method and analytic hierarchy process (AHP), an ecological vulnerability model was built for the calculation of the regional ecological vulnerability by means of RS and GIS spatial analysis. An analysis of the relationships between land use and ecological vulnerability was also made, and the results were tested by spatial auto-correlation analysis. Overall, the ecological vulnerability of the study area was at medium-high level. The exploitation of four opencast areas in the Coalfield caused a significant increase of ecological vulnerability. Moreover, due to the effects of mine drained water and human activities, the 300 -2000 m around the opencast areas was turning into higher ecologically fragile area. With further exploitation, the whole Coalfield was evolved into moderate and heavy ecological vulnerability area, and the coal resources mining was a key factor in this process. The cluster analysis showed that the spatial distribution of the ecological vulnerability in the study area had reasonable clustering characteristics. To decrease the population density, control the grazing capacity of grassland, and regulate the ratios of construction land and cultivated land could be the optimal ways for resolving the natural and social pressure, and to increase the investment and improve the vegetation recovery coefficient could be the fundamental measures for decreasing the ecological vulnerability of the study area.

A water-quality assessment of the Busseron Creek watershed, Sullivan, Vigo, Greene, and Clay Counties, Indiana

USGS Publications Warehouse

Eikenberry, Stephen E.

1978-01-01

Chemical quality of surface water in the 237-square mile Busseron Creek watershed, in Indiana, is significantly affected by drainage from coal mines and municipalities. Drainage from coal mines is primarily a problem of higher than normal dissolved-solids concentration, whereas, drainage from municipalities is generally a problem of bacteria and phytoplankton. Generally, the water is calcium bicarbonate type, except in streams affected by drainage from coal mines, where the water is a mixed calcium and magnesium sulfate type. Ranges of concentration (in milligrams per liter) of dissolved solids and of some of the chemical constituents dissolved in streams from September 1975 to July 1976 were: dissolved solids, from 104 to 2,610; iron, from 0.00 to 150; sulfate, from 14 to 1,900; chloride, from 3.3 to 130; nitrate (as nitroglen), from 0.01 to 5.3; phosphate (as phosphorus), from 0.1 to 1.7; and total organic carbon, from 2.4 to 60. Range of pH was from 2.7 to 9.6 Ranges of concentration of chlorinated hydrocarbons (in micrograms per kilogram) detected in bed material of streams were: aldrin, from 0.2 to 0.4; chlordane, from 0 to 13; DDE, from 0.0 to 0.3; dieldrin, from 0.0 to 9.8; and heptachlor epoxide, from 0 to 1.0. Streams draining municipalities had high populations of fecal coliform bacteria (as many as 46,000 colonies per 100 milliliter) and phytoplankton (as many as 190 ,000 cells per milliliter). Dissolved-oxygen concentration ranged from 2.8 to 15.0 milligrams per liter. 

Groundwater intensive exploitation and mining in Gran Canaria and Tenerife, Canary Islands, Spain: Hydrogeological, environmental, economic and social aspects.

PubMed

Custodio, Emilio; Cabrera, María Del Carmen; Poncela, Roberto; Puga, Luis-Olavo; Skupien, Elzbieta; Del Villar, Alberto

2016-07-01

Intensive exploitation and continuous consumption of groundwater reserves (groundwater mining) have been real facts for decades in arid and semiarid areas. A summary of experience in the hydrogeological, economic, social and ethical consequences of groundwater intensive and mining exploitation in Gran Canaria and Tenerife Islands, in the Canarian Archipelago, is presented. Groundwater abstraction is less than recharge, but a significant outflow of groundwater to the sea cannot be avoided, especially in Tenerife, due to its younger volcanic coastal formations. Consequently, the intensive aquifer groundwater development by means of wells and water galleries (tunnels) has produced a groundwater reserve depletion of about 2km(3). Should current groundwater abstraction cease, the recovery time to close-to-natural conditions is from decades to one century, except in the mid and high elevations of Tenerife, where this recovery is not possible as aquifer formations will remain permanently drained by the numerous long water galleries. The socio-economic circumstances are complex due to a long standing history of water resources exploitation, successive social changes on each island, and well-established groundwater water trading, with complex relationships that affect water governance and the resulting ethical concerns. Gran Canaria and Tenerife are in an advanced groundwater exploitation stage and have a large water demand. They are good examples that allow drawing guidelines to evaluate groundwater development on other small high islands. After presenting the hydrogeological background, the socio-economic results are discussed to derive general knowledge to guide on water governance. Copyright © 2016 Elsevier B.V. All rights reserved.

Abandoned mine drainage in the Swatara Creek Basin, southern anthracite coalfield, Pennsylvania, USA: 1. stream quality trends coinciding with the return of fish

USGS Publications Warehouse

Cravotta, Charles A.; Brightbill, Robin A.; Langland, Michael J.

2010-01-01

Acidic mine drainage (AMD) from legacy anthracite mines has contaminated Swatara Creek in eastern Pennsylvania. Intermittently collected base-flow data for 1959–1986 indicate that fish were absent immediately downstream from the mined area where pH ranged from 3.5 to 7.2 and concentrations of sulfate, dissolved iron, and dissolved aluminum were as high as 250, 2.0, and 4.7 mg/L, respectively. However, in the 1990s, fish returned to upper Swatara Creek, coinciding with the implementation of AMD treatment (limestone drains, limestone diversion wells, limestone sand, constructed wetlands) in the watershed. During 1996–2006, as many as 25 species of fish were identified in the reach downstream from the mined area, with base-flow pH from 5.8 to 7.6 and concentrations of sulfate, dissolved iron, and dissolved aluminum as high as 120, 1.2, and 0.43 mg/L, respectively. Several of the fish taxa are intolerant of pollution and low pH, such as river chub (Nocomis icropogon) and longnose dace (Rhinichthys cataractae). Cold-water species such as brook trout (Salvelinus fontinalis) and warm-water species such as rock bass (Ambloplites rupestris) varied in predominance depending on stream flow and stream temperature. Storm flow data for 1996–2007 indicated pH, alkalinity, and sulfate concentrations decreased as the stream flow and associated storm-runoff component increased, whereas iron and other metal concentrations were poorly correlated with stream flow because of hysteresis effects (greater metal concentrations during rising stage than falling stage). Prior to 1999, pH\\5.0 was recorded during several storm events; however, since the implementation of AMD treatments, pH has been maintained near neutral. Flow-adjusted trends for1997–2006 indicated significant increases in calcium; decreases in hydrogen ion, dissolved aluminum, dissolved and total manganese, and total iron; and no change in sulfate or dissolved iron in Swatara Creek immediately downstream from the mined area. The increased pH and calcium from limestone in treatment systems can be important for mitigating toxic effects of dissolved metals. Thus, treatment of AMD during the 1990s improved pH buffering, reduced metals transport, and helped to decrease metals toxicity to fish.

Reservoir-flooded river mouth areas as sediment traps revealing erosion from peat mining areas - Jukajoki case study in eastern Finland

NASA Astrophysics Data System (ADS)

Tahvanainen, Teemu; Meriläinen, Henna-Kaisa; Haraguchi, Akira; Simola, Heikki

2016-04-01

Many types of soil-disturbing land use have caused excess sedimentation in Finnish lakes. Identification and quantification of catchment sources of sediment material is crucial in cases where demands for remediation measures are considered. We studied recent (50 yr) sediments of four small rivers, all draining to a reservoir impounded in 1971. Catchments of two of the rivers had had peat mining activities from early 1980s until recently, exposing large areas of peat surfaces to erosion. The water level of the reservoir had risen to the river mouth areas of all rivers, while in each case, the river mouth areas still form riverine narrows separable from the main reservoir, hence collecting sedimentation from their own catchments. The original soils under the reservoir water level could readily be observed in core samples, providing a dated horizon under recent sediments. In addition, we used 137Cs-stratigraphies for dating of samples from original river bed locations. As expected, recent sediments of rivers with peat mining influence differed from others e.g. by high organic content and C:N ratios. Stable isotopes 13C and 15N both correlated with C:N (r = 0.799 and r = -0.717, respectively) and they also differentiated the peat-mining influenced samples from other river sediments. Principal components of the physical-chemical variables revealed clearer distinction than any variables separately. Light-microscopy revealed abundance of leafs of Sphagnum mosses in peat-mining influenced river sediments that were nearly absent from other rivers. Spores of Sphagnum were, however, abundant in all river sediments indicating their predominantly airborne origin. We find that combination of several physical-chemical characters rather than any single variable and microscopy of plant remains can result in reliable recognition of peatland-origin of sediment material when non-impacted sites are available for comparison. Dating of disturbed recent sediments is challenging. River-mouth areas with reservoir history can be particularly useful as the terrestrial soil strata provides a dated horizon under recent sediments.

Natural attenuation of mining pollutants in the transboundary Save River

NASA Astrophysics Data System (ADS)

Meck, M. L.; Masamba, W. R. L.; Atlhopheng, J.; Ringrose, S.

The objective of the study was to investigate the role played by the natural environment in protecting the transboundary Save River from the impacts of metals derived from phosphate mining at Dorowa. The study is a follow up study from a previous one that noted that there is natural attenuation at Dorowa. Water and sediment samples were collected in the Save River and the streams that drain the Dorowa dumps. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the cations (Na +, K +, Ca 2+, Mg 2+, Cu 2+, Co 2+, Fe 2+, Ni 2+, Zn 2+, Pb 2+, Sn 2+, Mn 2+, Cd 2+) in the samples. Major anions Cl -, SO42- and NO3- were analyzed by standard chromatography whilst CO32- and HCO3- were determined by titration. pH was measured on site. Geochemical modeling of the water composition was conducted with Visual Minteq. The results show that natural attenuation is being achieved through precipitation of solids from the water and subsequent deposition onto the sediments. Six of the metals are almost completely precipitated (Cu 99.99%, Fe 99.39%, Ni 91.24%, Pb 99.87%, Sn 99.99% and Zn 88.66%). However Mn, Co and Cd remain in solution. Thus the natural environment is protecting the Save River which is a transboundary river from the impacts of mining through precipitation of the metals. Users downstream of Dorowa mine are therefore not being affected by mining pollution. This study demonstrates that besides being a legitimate and important user of water, the natural environment can also play a significant role in protecting water quality by attenuating metals naturally. By analyzing costs incurred in several places where alternative methods are employed to remediate metal related pollution the study concludes that natural remediation at Dorowa is saving the nation in environmental costs. Therefore the paper advocates for appreciation of the role that the natural environment plays in protecting ecosystems from the impact of human developments and environmental costs. Subsequently, this calls for recognition of natural environment’s role in water resources management for the sustenance of ecosystems and peoples livelihoods.

Assessment, water-quality trends, and options for remediation of acidic drainage from abandoned coal mines near Huntsville, Missouri, 2003-2004

USGS Publications Warehouse

Christensen, Eric D.

2005-01-01

Water from abandoned underground coal mines acidifies receiving streams in the Sugar Creek Basin and Mitchell Mine Basin near Huntsville, Missouri. A 4.35-kilometer (2.7-mile) reach of Sugar Creek has been classified as impaired based on Missouri's Water Quality Standards because of small pH values [< (less than) 6.5]. Samples collected from Sugar Creek from July 2003 to June 2004 did not have pH values outside of the specified range of 6.5 to 9.0. However, large concentrations of iron [416 to 2,320 mg/L (milligrams per liter)], manganese (8.36 to 33.5 mg/L), aluminum (0.870 to 428 mg/L), and sulfate (2,990 to 13,700 mg/L) in acidic mine drainage (AMD) from two mine springs as well as small and diffuse seeps were observed to have an effect on water quality in Sugar Creek. Metal and sulfate loads increased and pH decreased immediately downstream from Sugar Creek's confluence with the Calfee Slope and Huntsville Gob drainages that discharge AMD into Sugar Creek. Similar effects were observed in the Mitchell Mine drainage that receives AMD from a large mine spring. Comparisons of water-quality samples from this study and two previous studies by the U.S. Geological Survey in 1987-1988 and the Missouri Department of Natural Resources in 2000-2002 indicate that AMD generation in the Sugar Creek Basin and Mitchell Mine Basin is declining, but the data are insufficient to quantify any trends or time frame. AMD samples from the largest mine spring in the Calfee Slope subbasin indicated a modest but significant increase in median pH from 4.8 to 5.2 using the Wilcoxan rank-sum test (p <0.05) and a decrease in median specific conductance from 5,000 to 3,540 ?S/cm (microsiemens per centimeter at 25 degrees Celsius) during a 17-year period. AMD samples from the largest mine spring in the Mitchell Mine Basin indicated an increase in median pH values from 5.6 to 6.0 and a decrease in median specific conductance from 3,050 to 2,450 ?S/cm during the same period. Remediation of AMD at or near the sites of the three largest mine springs is geochemically feasible based on alkalinity addition rates and increased pH determined by cubitainer experiments and geochemical mixing experiments using the computer model PHREEQCI. Alkalinity values for seven cubitainer experiments conducted to simulate anoxic treatment options exceeded the targeted value for alkalinity [90 mg/L as calcium carbonate (CaCO3)] specified in Missouri's Total Maximum Daily Load program by 18 percent or more, but maximum pH values were between 6.2 and 6.3, which is less than the targeted pH value of 6.5. Treatment of AMD by mixing with stream water or sewage effluent can further increase pH as indicated by geochemical modeling, but will not totally achieve water-quality goals because of limited discharges. A combination of treatments including settling ponds, oxic or anoxic limestone drains, and possibly successive alkalinity producing systems to remediate AMD will likely be required in the Sugar Creek Basin and Mitchell Mine Basin to consistently meet Missouri's Water Quality Standards.

Mercury and methylmercury in water and sediment of the Sacramento River Basin, California

USGS Publications Warehouse

Domagalski, Joseph L.

2001-01-01

Mercury (Hg) and methylmercury (CH3Hg+) concentrations in streambed sediment and water were determined at 27 locations throughout the Sacramento River Basin, CA. Mercury in sediment was elevated at locations downstream of either Hg mining or Au mining activities where Hg was used in the recovery of Au. Methylmercury in sediment was highest (2.84 ng/g) at a location with the greatest wetland land cover, in spite of lower total Hg at that site relative to other river sites. Mercury in unfiltered water was measured at 4 locations on the Sacramento River and at tributaries draining the mining regions, as well as agricultural regions. The highest levels of Hg in unfiltered water (2248 ng/l) were measured at a site downstream of a historic Hg mining area, and the highest levels at all sites were measured in samples collected during high streamflow when the levels of suspended sediment were also elevated. Mercury in unfiltered water exceeded the current federal and state recommended criterion for protection of aquatic life (50 ng/l as total Hg in unfiltered water) only during high streamflow conditions. The highest loading of Hg to the San Francisco Bay system was attributed to sources within the Cache Creek watershed, which are downstream of historic Hg mines, and to an unknown source or sources to the mainstem of the Sacramento River upstream of historic Au mining regions. That unknown source is possibly associated with a volcanic deposit. Methylmercury concentrations also were dependent on season and hydrologic conditions. The highest levels (1.98 ng/l) in the Sacramento River, during the period of study, were measured during a major flood event. The reactivity of Hg in unfiltered water was assessed by measuring the amount available for reaction by a strong reducing agent. Although most Hg was found to be nonreactive, the highest reactivity (7.8% of the total Hg in water) was measured in the sample collected from the same site with high CH3Hg+ in sediment, and during the time of year when that site was under continual flooded conditions. Although Hg concentrations in water downstream of the Hg mining operations were measured as high as 2248 ng/l during stormwater runoff events, the transported Hg was found to have a low potential for geochemical transformations, as indicated by the low reactivity to the reducing agent (0.0001% of the total), probably because most of the Hg in the unfiltered water sample was in the mercury sulfide form.

Occurrence and transport of total mercury and methyl mercury in the Sacramento River Basin, California

USGS Publications Warehouse

Domagalski, Joseph L.

1999-01-01

Mercury poses a water-quality problem for California's Sacramento River, a large river with a mean annual discharge of over 650 m3/s. This river discharges into the San Francisco Bay, and numerous fish species of the bay and river contain mercury levels high enough to affect human health if consumed. Two possible sources of mercury are the mercury mines in the Coast Ranges and the gold mines in the Sierra Nevada. Mercury was once mined in the Coast Ranges, west of the Sacramento River, and used to process gold in the Sierra Nevada, east of the river. The mineralogy of the Coast Ranges mercury deposits is mainly cinnabar (HgS), but elemental mercury was used to process gold in the Sierra Nevada. Residual mercury from mineral processing in the Sierra Nevada is mainly in elemental form or in association with oxide particles or organic matter and is biologically available. Recent bed-sediment sampling, at sites below large reservoirs, showed elevated levels of total mercury (median concentration 0.28 ??g/g) in every large river (the Feather, Yuba, Bear, and American rivers) draining the Sierra Nevada gold region. Monthly sampling for mercury in unfiltered water shows relatively low concentrations during the nonrainy season in samples collected throughout the Sacramento River Basin, but significantly higher concentrations following storm-water runoff. Measured concentrations, following storm-water runoff, frequently exceeded the state of California standards for the protection of aquatic life. Results from the first year of a 2-year program of sampling for methyl mercury in unfiltered water showed similar median concentrations (0.1 ng/l) at all sampling locations, but with apparent high seasonal concentrations measured during autumn and winter. Methyl mercury concentrations were not significantly higher in rice field runoff water, even though rice production involves the creation of seasonal wetlands: higher rates of methylation are known to occur in stagnant wetland environments that have high dissolved carbon.Mercury poses a water-quality problem for California's Sacramento River, a large river with a mean annual discharge of over 650 m3/s. This river discharges into the San Francisco Bay, and numerous fish species of the bay and river contain mercury levels high enough to affect human health if consumed. Two possible sources of mercury are the mercury mines in the Coast Ranges and the gold mines in the Sierra Nevada. Mercury was once mined in the Coast Ranges, west of the Sacramento River, and used to process gold in the Sierra Nevada east of the river. The mineralogy of the Coast Ranges mercury deposits is mainly cinnabar (HgS), but elemental mercury was used to process gold in the Sierra Nevada. Residual mercury from mineral processing in the Sierra Nevada is mainly in elemental form or in association with oxide particles or organic matter and is biologically available. Recent bed-sediment sampling, at sites below large reservoirs, showed elevated levels of total mercury (median concentration 0.28 ??g/g) in every large river (the Feather, Yuba, Bear, and American rivers) draining the Sierra Nevada gold region. Monthly sampling for mercury in unfiltered water shows relatively low concentrations during the nonrainy season in samples collected throughout the Sacramento River Basin, but significantly higher concentrations following storm-water runoff. Measured concentrations, following storm-water runoff, frequently exceeded the state of California standards for the protection of aquatic life. Results from the first year of a 2-year program of sampling for methyl mercury in unfiltered water showed similar median concentrations (0.1 ng/l) at all sampling locations, but with apparent high seasonal concentrations measured during autumn and winter. Methyl mercury concentrations were not significantly higher in rice field runoff water, even though rice production involves the creation of seasonal wetlands: higher rates of methylation a

Long-Term Impacts on Macroinvertebrates Downstream of Reclaimed Mountaintop Mining Valley Fills in Central Appalachia

NASA Astrophysics Data System (ADS)

Pond, Gregory J.; Passmore, Margaret E.; Pointon, Nancy D.; Felbinger, John K.; Walker, Craig A.; Krock, Kelly J. G.; Fulton, Jennifer B.; Nash, Whitney L.

2014-10-01

Recent studies have documented adverse effects to biological communities downstream of mountaintop coal mining and valley fills (VF), but few data exist on the longevity of these impacts. We sampled 15 headwater streams with VFs reclaimed 11-33 years prior to 2011 and sampled seven local reference sites that had no VFs. We collected chemical, habitat, and benthic macroinvertebrate data in April 2011; additional chemical samples were collected in September 2011. To assess ecological condition, we compared VF and reference abiotic and biotic data using: (1) ordination to detect multivariate differences, (2) benthic indices (a multimetric index and an observed/expected predictive model) calibrated to state reference conditions to detect impairment, and (3) correlation and regression analysis to detect relationships between biotic and abiotic data. Although VF sites had good instream habitat, nearly 90 % of these streams exhibited biological impairment. VF sites with higher index scores were co-located near unaffected tributaries; we suggest that these tributaries were sources of sensitive taxa as drifting colonists. There were clear losses of expected taxa across most VF sites and two functional feeding groups (% scrapers and %shredders) were significantly altered. Percent VF and forested area were related to biological quality but varied more than individual ions and specific conductance. Within the subset of VF sites, other descriptors (e.g., VF age, site distance from VF, the presence of impoundments, % forest) had no detectable relationships with biological condition. Although these VFs were constructed pursuant to permits and regulatory programs that have as their stated goals that (1) mined land be reclaimed and restored to its original use or a use of higher value, and (2) mining does not cause or contribute to violations of water quality standards, we found sustained ecological damage in headwaters streams draining VFs long after reclamation was completed.

Methane Emissions from Semi-natural, Drained and Re-wetted Peatlands in Germany

NASA Astrophysics Data System (ADS)

Tiemeyer, B.; Bechtold, M.; Albiac Borraz, E.; Augustin, J.; Drösler, M.; Beetz, S.; Beyer, C.; Eickenscheidt, T.; Fiedler, S.; Förster, C.; Giebels, M.; Glatzel, S.; Heinichen, J.; Höper, H.; Leiber-Sauheitl, K.; Peichl-Brak, M.; Rosskopf, N.; Sommer, M.; Zeitz, J.; Freibauer, A.

2014-12-01

Drained peatlands contribute around 5% to the total German greenhouse gas emissions. While these areas are hotspots for carbon dioxide (CO2) and nitrous oxide (N2O) emissions, some re-wetted peatlands may emit large amounts of methane (CH4). To quantify the GHG emission reductions achieved by the re-wetting of peatlands, the reduced CO2 emissions and the potential CH4fluxes need to be balanced. We synthesized methane flux data from 14 peatlands with 122 sites. At each site, methane fluxes were measured for one to three years with static chambers. The sites comprise arable land, intensive and extensive grassland, forest and peat mining areas as well as semi-natural and re-wetted peatlands on both bog peat, fen peat and other soils rich in organic carbon. Besides the groundwater table we consider further potential drivers for the CH4fluxes such as soil properties (carbon, nitrogen, pH, and physical properties), climatic parameters, land use, and vegetation composition. Annual methane fluxes ranged from low uptake rates (around -1 g CH4-C m² a-1) to very high emissions (> 200 g CH4-C m² a-1). Intensively drained sites showed very low emissions, while for annual mean water levels higher than 5-10 cm below ground, elevated emissions of more than 20 g CH4-C may occur. At some re-wetted sites CH4 emissions of more than 100 g CH4-C m² a-1 were measured, which roughly equal the Global Warming Potential of the CO2-emissions from intensively drained agricultural sites. These high fluxes were probably caused by a combination of nutrient-rich conditions, the dieback of poorly adapted plants and a fast accumulation of organic sediments. However, this was the exception and not the rule even for very wet re-wetted sites. Achieving a model efficiency of 0.72 during cross-validation, a boosted regression tree (BRT) model was well able to describe logarithmic CH4-fluxes. Groundwater level, biotope type, soil nitrogen content, and ponding duration during summer were the most important controls. Combining the BRT model with soil, land use, and groundwater table maps as well as weather data, methane fluxes were upscaled for Germany.

Chemical quality of surface water in the West Branch Susquehanna River basin, Pennsylvania

USGS Publications Warehouse

McCarren, Edward F.

1964-01-01

The West Branch Susquehanna River is 228 miles long and drains 6,913 square miles of mountainous area in central Pennsylvania. Much of this area is forestcovered wilderness, part of which is reserved as State game land. Wild animals, such as deer, bear, turkey and grouse, are sheltered there, and many streams contain trout and other game fish. This helps to make the region one of the best hunting and fishing areas in Pennsylvania. The Congress has approved Federal funds for the construction of several reservoirs to prevent flooding of the main river and several of its tributaries. Water stored behind the dams will not be withdrawn below a minimum level designated as conservation pools. These pools will be available for recreation. Several headwater streams, such as Clearfield, Moshannon, and at times Sinnemahoning Creek, that carry drainage from coal mines are acid and contain high concentrations of dissolved solids, especially sulfates. These streams acidify the West Branch Susquehanna River downstream as far as Jersey Shore. One of the most influential tributaries affecting the quality of the West Branch Susquehanna River after they merge is Bald Eagle Creek. Bald Eagle Creek enters the main river downstream from Lock Haven which is approximately 100 river miles from the river's source. Because of its alkaline properties, water of Bald Eagle Creek can neutralize acidic water. Many streams draining small areas and several draining large areas such as Pine Creek, Lycoming Creek, and Loyalsock Creek are clear nearly neutral water low in dissolved solids whose pH is about 7.0 most of the time. These streams have a diluting and neutralizing effect on the quality of the West Branch Susquehanna River, so that from Williamsport downstream the river water is rarely acid, and for most of the time it is of good chemical quality.

Quality of water and sediment in streams affected by historical mining, and quality of Mine Tailings, in the Rio Grande/Rio Bravo Basin, Big Bend Area of the United States and Mexico, August 2002

USGS Publications Warehouse

Lambert, Rebecca B.; Kolbe, Christine M.; Belzer, Wayne

2008-01-01

The U.S. Geological Survey, in cooperation with the International Boundary and Water Commission - U.S. and Mexican Sections, the National Park Service, the Texas Commission on Environmental Quality, the Secretaria de Medio Ambiente y Recursos Naturales in Mexico, the Area de Proteccion de Flora y Fauna Canon de Santa Elena in Mexico, and the Area de Proteccion de Flora y Fauna Maderas del Carmen in Mexico, collected samples of stream water, streambed sediment, and mine tailings during August 2002 for a study to determine whether trace elements from abandoned mines in the area in and around Big Bend National Park have affected the water and sediment quality in the Rio Grande/Rio Bravo Basin of the United States and Mexico. Samples were collected from eight sites on the main stem of the Rio Grande/Rio Bravo, four Rio Grande/Rio Bravo tributary sites downstream from abandoned mines or mine-tailing sites, and 11 mine-tailing sites. Mines in the area were operated to produce fluorite, germanium, iron, lead, mercury, silver, and zinc during the late 1800s through at least the late 1970s. Moderate (relatively neutral) pHs in stream-water samples collected at the 12 Rio Grande/Rio Bravo main-stem and tributary sites indicate that water is well mixed, diluted, and buffered with respect to the solubility of trace elements. The highest sulfate concentrations were in water samples from tributaries draining the Terlingua mining district. Only the sample from the Rough Run Draw site exceeded the Texas Surface Water Quality Standards general-use protection criterion for sulfate. All chloride and dissolved solids concentrations in water samples were less than the general-use protection criteria. Aluminum, copper, mercury, nickel, selenium, and zinc were detected in all water samples for which each element was analyzed. Cadmium, chromium, and lead were detected in samples less frequently, and silver was not detected in any of the samples. None of the sample concentrations of aluminum, cadmium, chromium, nickel, selenium, and zinc exceeded the Texas Surface Water Quality Standards criteria for aquatic life-use protection or human health. The only trace elements detected in the water samples at concentrations exceeding the Texas Surface Water Quality Standards criterion for human health (fish consumption use) was lead at one site and mercury at 10 of 12 sites. Relatively high mercury concentrations distributed throughout the area might indicate sources of mercury in addition to abandoned mining areas. Streambed-sediment samples were collected from 12 sites and analyzed for 44 major and trace elements. In general, the trace elements detected in streambed-sediment samples were low in concentration, interpreted as consistent with background concentrations. Concentrations at two sites, however, were elevated compared to Texas Commission on Environmental Quality criteria. Concentrations of antimony, arsenic, cadmium, lead, silver, and zinc in the sample from San Carlos Creek downstream from La Esperanza (San Carlos) Mine exceeded the Texas Commission on Environmental Quality screening levels for sediment. The sample from Rough Run Draw, downstream from the Study Butte Mine, also showed elevated concentrations of arsenic, cadmium, and lead, but these concentrations were much lower than those in the San Carlos Creek sample and did not exceed screening levels. Elevated concentrations of multiple trace elements in streambed-sediment samples from San Carlos Creek and Rough Run Draw indicate that San Carlos Creek, and probably Rough Run Draw, have been adversely affected by mining activities. Fourteen mine-tailing samples from 11 mines were analyzed for 25 major and trace elements. All trace elements except selenium and thallium were detected in one or more samples. The highest lead concentrations were detected in tailings samples from the Boquillas, Puerto Rico, La Esperanza (San Carlos), and Tres Marias Mines, as might be expected because the tailings ar

Physical and hydrologic environments of the Mulberry coal reserves in eastern Kansas

USGS Publications Warehouse

Kenny, J.F.; Bevans, H.E.; Diaz, A.M.

1982-01-01

Strippable reserves of Mulberry coal underlie an area of approximately 300 square miles of Miami, Linn, and Bourbon Counties of eastern Kansas. Although subject to State reclamation law, current and projected strip mining of this relatively thin coal seam could alter and hydrologic environment of the study area. Drained by the Marais des Cygnes and Little Osage Rivers and their tributaries, this area is characterized by low relief and moderately impermeable soils. Streamflows are poorly sustained by ground-water discharge and fluctuate widely due to climatic extremes and usage of surface-water supplies. Because ground-water supplies are generally unreliable in quantity and quality, surface water is used to meet most water requirements in the study area. Primary used of surface waters are for domestic supplies, maintenance of wildlife and recreational areas, and cooling needs at LaCygne Power Plant. The prevailing chemical type of the natural streamflow is calcium bicarbonate, with concentrations of dissolved solids generally less than 500 milligrams per liter and pH near neutral. Additional streamflow and water-quality data are needed to evaluate the premining characteristics of and the anticipated changes in the hydrologic environment as strip mining proceeds within the study area. A network of data-collection stations and a sampling scheme have been established to acquire this additional information. (USGS)

Geohydrologic reconnaissance of drainage wells in Florida; an interim report

USGS Publications Warehouse

Kimrey, Joel O.; Fayard, Larry D.

1982-01-01

Drainage wells are used to inject surface waters directly into an aquifer, or shallow ground waters directly into a deeper aquifer, primarily by gravity. Such wells in Florida may be grouped into two broad types: (1) Surface-water injection wells, and (2) interaquifer connector wells. Surface-water injection wells are commonly used to supplement drainage for urban areas in karst terranes of central and north Florida. Data are available for 25 wells in the Ocala, Live Oak, and Orlando areas that allow comparison of the quality of water samples from these Floridan aquifer drainage wells with allowable contaminant levels. Comparison indicates that maximum contaminant levels for turbidity, color, and iron, manganese, and lead concentrations are equaled or exceeded in some drainage-well samples, and relatively high counts for coliform bacteria are present in most wells. Interaquifer connector wells are used in the phosphate mining areas of Polk and Hillsborough Counties, to drain mining operations and recharge the Floridan aquifer. Water-quality data available from 13 connector wells indicate that samples from most of these wells exceed standards values for iron concentration and turbidity. One well yielded a highly mineralized water, and samples from 6 of the other 12 wells exceed standards values for gross alpha concentrations. (USGS)

Sedimentary processes in the Carnot Formation (Central African Republic) related to the palaeogeographic framework of Central Africa

NASA Astrophysics Data System (ADS)

Censier, Claude; Lang, Jacques

1999-08-01

The depositional environment, provenance and processes of emplacement of the detrital material of the Mesozoic Carnot Formation are defined, by bedding and sedimentological analysis of its main facies, and are reconstructed within the palaeogeographic framework of Central Africa. The clastic material was laid down between probably the Albian and the end of the Cretaceous, in a NNW-oriented braided stream fluvial system that drained into the Doba Trough (Chad) and probably also into the Touboro Basin (Cameroon). The material was derived from weathering of the underlying Devonian-Carboniferous Mambéré Glacial Formation and of the Precambrian schist-quartzite complex located to the south of the Carnot Formation. These results provide useful indications as to the provenance of diamonds mined in the southwest Central African Republic.

14 CFR 23.1021 - Oil system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil system drains. 23.1021 Section 23.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain...

14 CFR 23.1021 - Oil system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil system drains. 23.1021 Section 23.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain...

A prospective randomized study of use of drain versus no drain after burr-hole evacuation of chronic subdural hematoma.

PubMed

Singh, Amit Kumar; Suryanarayanan, Bhaskar; Choudhary, Ajay; Prasad, Akhila; Singh, Sachin; Gupta, Laxmi Narayan

2014-01-01

Chronic subdural hematoma (CSDH) recurs after surgical evacuation in 5-30% of patients. Inserting subdural drain might reduce the recurrence rate, but is not commonly practiced. There are few prospective studies to evaluate the effect of subdural drains. A prospective randomized study to investigate the effect of subdural drains in the on recurrence rates and clinical outcome following burr-hole drainage (BHD) of CSDH was undertaken. During the study period, 246 patients with CSDH were assessed for eligibility. Among 200 patients fulfilling the eligibility criteria, 100 each were assigned to "drain group" (drain inserted into the subdural space following BHD) and "without drain group" (subdural drain was not inserted following BHD) using random allocation software. The primary end point was recurrence needing re-drainage up to a period of 6 months from surgery. Recurrence occurred in 9 of 100 patients with a drain, and 26 of 100 patients in without drain group (P = 0.002). The mortality was 5% in patients with drain and 4% in patients without drain group (P = 0.744). The medical and surgical complications were comparable between the two study groups. Use of a subdural drain after burr-hole evacuation of a CSDH reduces the recurrence rate and is not associated with increased complications.

14 CFR 23.1021 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil system drains. 23.1021 Section 23.1021... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Oil System § 23.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain...

14 CFR 29.1021 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil system drains. 29.1021 Section 29.1021... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 27.1021 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil system drains. 27.1021 Section 27.1021... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible; and (b...

14 CFR 25.1021 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil system drains. 25.1021 Section 25.1021... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 25.1021 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil system drains. 25.1021 Section 25.1021... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 23.1021 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil system drains. 23.1021 Section 23.1021... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Oil System § 23.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain...

14 CFR 29.1021 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil system drains. 29.1021 Section 29.1021... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 27.1021 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil system drains. 27.1021 Section 27.1021... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible; and (b...

Mass loads of dissolved and particulate mercury and other trace elements in the Mt. Amiata mining district, Southern Tuscany (Italy)

USGS Publications Warehouse

Rimondi, V.; Costagliola, P.; Gray, J.E.; Lattanzi, P.; Nannucci, M.; Paolieri, M.; Salvadori, A.

2014-01-01

Total dissolved and particulate mercury (Hg), arsenic (As), and antimony (Sb) mass loads were estimated in different seasons (March and September 2011 and March 2012) in the Paglia River basin (PRB) (central Italy). The Paglia River drains the Mt. Amiata Hg district, one of the largest Hg-rich regions worldwide. Quantification of Hg, As, and Sb mass loads in this watershed allowed (1) identification of the contamination sources, (2) evaluation of the effects of Hg on the environment, and (3) determination of processes affecting Hg transport. The dominant source of Hg in the Paglia River is runoff from Hg mines in the Mt. Amiata region. The maximum Hg mass load was found to be related to runoff from the inactive Abbadia San Salvatore Mine (ASSM), and up to 30 g day−1 of Hg, dominantly in the particulate form, was transported both in high and low flow conditions in 2011. In addition, enrichment factors (EFs) calculated for suspended particulate matter (SPM) were similar in different seasons indicating that water discharge controls the quantities of Hg transported in the PRB, and considerable Hg was transported in all seasons studied. Overall, as much as 11 kg of Hg are discharged annually in the PRB and this Hg is transported downstream to the Tiber River, and eventually to the Mediterranean Sea. Similar to Hg, maximum mass loads for As and Sb were found in March 2011, when as much as 190 g day−1 each of As and Sb were measured from sites downstream from the ASSM. Therefore, the Paglia River represents a significant source of Hg, Sb, and As to the Mediterranean Sea.

Changing trends of rainfall and sediment fluxes in the Kinta River catchment, Malaysia

NASA Astrophysics Data System (ADS)

Ismail, W. R.; Hashim, M.

2015-03-01

The Kinta River, draining an area of 2566 km2, originates in the Korbu Mountain in Perak, Malaysia, and flows through heterogeneous, mixed land uses ranging from extensive forests to mining, rubber and oil palm plantations, and urban development. A land use change analysis of the Kinta River catchment was carried out together with assessment of the long-term trend in rainfall and sediment fluxes. The Mann-Kendall test was used to examine and assess the long-term trends in rainfall and its relationship with the sediment discharge trend. The land use analysis shows that forests, water bodies and mining land declined whilst built and agricultural land use increased significantly. This has influenced the sediment flux of the catchment. However, most of the rainfall stations and river gauging stations are experiencing an increasing trends, except at Kinta river at Tg. Rambutan. Sediment flux shows a net erosion for the period from 1961 to 1969. The total annual sediment discharge in the Kinta River catchment was low with an average rate of 1,757 t/km2/year. From 1970 to 1985, the annual sediment yield rose to an average rate of 4062 t/km2/year. Afterwards, from 1986 to 1993, the total annual sediment discharge decreased to an average rate of 1,306 t/km2/year and increased back during the period 1994 to 2000 to 2109 t/km2/year. From 2001 to 2006 the average sediment flux rate declined to 865 t/km2/year. The decline was almost 80% from the 1970s. High sediment flux in the early 1970s is partly associated with reduced tin mining activities in the area. This decreasing trend in sediment delivery leaving the Kinta River catchment is expected to continue dropping in the future.

Diminished Metal Accumulation in Riverine Fishes Exposed to Acid Mine Drainage over Five Decades

PubMed Central

Jeffree, Ross A.; Markich, Scott J.; Twining, John R.

2014-01-01

Bony bream (Nematalosa erebi) and black catfish (Neosilurus ater) were sampled from the fresh surface waters of the Finniss River in tropical northern Australia, along a metal pollution gradient draining the Rum Jungle copper/uranium mine, a contaminant source for over five decades. Paradoxically, populations of both fish species exposed to the highest concentrations of mine-related metals (cobalt, copper, lead, manganese, nickel, uranium and zinc) in surface water and sediment had the lowest tissue (bone, liver and muscle) concentrations of these metals. The degree of reduction in tissue concentrations of exposed populations was also specific to each metal and inversely related to its degree of environmental increase above background. Several explanations for diminished metal bioaccumulation in fishes from the contaminated region were evaluated. Geochemical speciation modeling of metal bioavailability in surface water showed no differences between the contaminated region and the control sites. Also, the macro-nutrient (calcium, magnesium and sodium) water concentrations, that may competitively inhibit metal uptake, were not elevated with trace metal contamination. Reduced exposure to contaminants due to avoidance behavior was unlikely due to the absence of refugial water bodies with the requisite metal concentrations lower than the control sites and very reduced connectivity at time of sampling. The most plausible interpretation of these results is that populations of both fish species have modified kinetics within their metal bioaccumulation physiology, via adaptation or tolerance responses, to reduce their body burdens of metals. This hypothesis is consistent with (i) reduced tissue concentrations of calcium, magnesium and sodium (macro-nutrients), in exposed populations of both species, (ii) experimental findings for other fish species from the Finniss River and other contaminated regions, and (iii) the number of generations exposed to likely selection pressure over 50 years. PMID:24663964

The respiratory health hazard of tephra from the 2010 Centennial eruption of Merapi with implications for occupational mining of deposits

NASA Astrophysics Data System (ADS)

Damby, D. E.; Horwell, C. J.; Baxter, P. J.; Delmelle, P.; Donaldson, K.; Dunster, C.; Fubini, B.; Murphy, F. A.; Nattrass, C.; Sweeney, S.; Tetley, T. D.; Tomatis, M.

2013-07-01

Ashfall into heavily populated areas during the October-November 2010 eruption of Merapi volcano, Indonesia created anxiety regarding the growing impacts to health as the eruption escalated and the hazard zone widened. We made a preliminary assessment of the respiratory hazards to human health of the tephra deposits (ashfall, lahar, and PDC surge) from the eruption using a laboratory protocol specifically developed to study the toxic potential of volcanic ash particles. Twenty samples collected from a range of locations were analysed for health-pertinent mineralogical parameters (grain size, crystalline silica content, morphology, surface area, bulk chemistry, and leachable elements) and bio-reactivity (hydroxyl radical generation, haemolytic potential, oxidative capacity, pro-inflammatory response). The grain size pertinent to respiratory health was variable, ranging from 1.4-15.6 vol.% sub-4 μm and 3.0-28.9 vol.% sub-10 μm diameter material. No fibre-like particles were observed. Cristobalite was present in all samples, ranging from 1.9-9.5 wt.%, but surface reactivity and in vitro toxicity assays showed low reactivity for all samples tested. The risk of direct exposure to ash from fallout was in any case low due to seasonal rains limiting its re-suspension and the immediate and effective clean-up of communities by local people who supplied the ash to the Indonesian construction industry for use as aggregate. However, mining of the lahar and thick PDC deposits in the valleys draining the volcano is performed on a vast, industrial scale, which could result in high occupational exposure to thousands of sand miners at Merapi during the dry seasons. Further study of the health hazard of the mined Merapi deposits is warranted.

Stable, geochemically mediated biospheres in the Deep Mine Microbial Observatory, SD, USA

NASA Astrophysics Data System (ADS)

Osburn, M. R.; Casar, C. P.; Kruger, B.; Flynn, T. M.

2017-12-01

The terrestrial subsurface is a vast reservoir of life, hosting diverse microbial ecosystems with varying levels of connectivity to surface inputs. Understanding long term ecosystem dynamics within the subsurface biosphere is very challenging due to limitations in accessibility, sample availability, and slow microbial growth rates. The establishment of the Deep Mine Microbial Observatory (DeMMO) at the Sanford Underground Research Facility, SD, USA has allowed for bimonthly sampling for nearly two years at six sites spanning 250 to 1500 m below the surface. Here we present a time-resolved analysis of the geomicrobiology of the six DeMMO sites, which have been created from legacy mine boreholes modified to allow for controlled sampling. Our interdisciplinary approach includes analysis of passively draining fracture fluid for aqueous and gas geochemistry, DNA sequencing, microscopy, and isotopic measurements of organic and inorganic substrates. Fluid geochemistry varies significantly between sites, but is relatively stable over time for a given site, even through significant external perturbations such as drilling and installation of permanent sampling devices into the boreholes. The fluid-hosted microbial diversity follows these trends, with consistent populations present at each site through time, even through drilling events. For instance, the shallowest site (DeMMO 1) consistently hosts >30% uncharacterized phyla and >25% Omnitrophica whereas the deepest site (DeMMO 6) is dominated by Firmicutes and Bacterioidetes. Microbial diversity appears to respond to the availability of energy sources such as organic carbon, sulfate, sulfide, hydrogen, and iron. Carbon isotopic measurements reveal closed system behavior with significant recycling of organic carbon into the DIC pool. Together these observations suggest DeMMO hosts isolated subsurface microbial populations adapted to local geochemistry that are stable on yearlong timescales.

Timing of Re-Transfusion Drain Removal Following Total Knee Replacement

PubMed Central

Leeman, MF; Costa, ML; Costello, E; Edwards, D

2006-01-01

INTRODUCTION The use of postoperative drains following total knee replacement (TKR) has recently been modified by the use of re-transfusion drains. The aim of our study was to investigate the optimal time for removal of re-transfusion drains following TKR. PATIENTS AND METHODS The medical records of 66 patients who had a TKR performed between October 2003 and October 2004 were reviewed; blood drained before 6 h and the total volume of blood drained was recorded. RESULTS A total of 56 patients had complete records of postoperative drainage. The mean volume of blood collected in the drain in the first 6 h was 442 ml. The mean total volume of blood in the drain was 595 ml. Therefore, of the blood drained, 78% was available for transfusion. CONCLUSION Re-transfusion drains should be removed after 6 h, when no further re-transfusion is permissible. PMID:16551400

A Brief History of Two Common Surgical Drains.

PubMed

Meyerson, Joseph M

2016-01-01

The use of surgical drains is commonplace in all types of surgical procedures, and rarely do we take the time to contemplate or investigate the origins of these critical devices. Every surgeon should be familiar with the Jackson-Pratt drain and Blake drain, 2 of the most frequently used closed suction, negative-pressure drainage devices in surgery. These drains are used throughout the body in a wide variety of surgical procedures. The development and differences between these 2 devices are seldom known by the practicing surgeon. In this article, we delve into the ancient history of drains, the creation and alterations of the closed suction, negative-pressure drain that paved the way for the Jackson-Pratt and Blake drain. Finally, we will discuss the variety of reservoirs that attach to these drains and the origin of the well-known adage of when to pull a drain.

A study of the complications of small bore 'Seldinger' intercostal chest drains.

PubMed

Davies, Helen E; Merchant, Shairoz; McGown, Anne

2008-06-01

Use of small bore chest drains (<14F), inserted via the Seldinger technique, has increased globally over the last few years. They are now used as first line interventions in most acute medical situations when thoracostomy is required. Limited data are available on the associated complications. In this study, the frequency of complications associated with 12F chest drains, inserted using the Seldinger technique, was quantified. A retrospective case note audit was performed of consecutive patients requiring pleural drainage over a 12-month period. One hundred consecutive small bore Seldinger (12F) chest drain insertions were evaluated. Few serious complications occurred. However, 21% of the chest drains were displaced ('fell out') and 9% of the drains became blocked. This contributed to high morbidity rates, with 13% of patients requiring repeat pleural procedures. The frequency of drain blockage in pleural effusion was reduced by administration of regular normal saline drain flushes (odds ratio for blockage in flushed drains compared with non-flushed drains 0.04, 95% CI: 0.01-0.37, P < 0.001). Regular chest drain flushes are advocated in order to reduce rates of drain blockage, and further studies are needed to determine optimal fixation strategies that may reduce associated patient morbidity.

Comparison of a large and small-calibre tube drain for managing spontaneous pneumothoraces.

PubMed

Benton, Ian J; Benfield, Grant F A

2009-10-01

To compare treatment success of large- and small-bore chest drains in the treatment of spontaneous pneumothoraces the case-notes were reviewed of those admitted to our hospital with a total of 73 pneumothoraces and who were treated by trainee doctors of varying experience. Both a large- and a small-bore intercostal tube drain system were in use during the two-year period reviewed. Similar pneumothorax profile and numbers treated with both drains were recorded, resulting in a similar drain time and numbers of successful and failed re-expansion of pneumothoraces. Successful pneumothorax resolution was the same for both drain types and the negligible tube drain complications observed with the small-bore drain reflected previously reported experiences. However the large-bore drain was associated with a high complication rate (32%) with more infectious complications (24%). The small-bore drain was prone to displacement (21%). There was generally no evidence of an increased failure and morbidity, reflecting poorer expertise, in the non-specialist trainees managing the pneumothoraces. A practical finding however was that in those large pneumothoraces where re-expansion failed, the tip of the drain had not been sited at the apex of the pleural cavity irrespective of the drain type inserted.

Analytical Results for 35 Mine-Waste Tailings Cores and Six Bed-Sediment Samples, and An Estimate of the Volume of Contaminated Material at Buckeye Meadow on Upper Basin Creek, Northern Jefferson County, Montana

USGS Publications Warehouse

Fey, David L.; Church, Stan E.; Finney, Christopher J.

1999-01-01

Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana have been implicated in their detrimental effects on water quality with regard to acid-generation and toxic-metal solubilization. Flotation-mill tailings in the meadow below the Buckeye mine, hereafter referred to as the Buckeye mill-tailings site, have been identified as significant contributors to water quality degradation of Basin Creek, Montana. Basin Creek is one of three tributaries to the Boulder River in the study area; bed sediments and waters draining from the Buckeye mine have also been implicated. Geochemical analysis of 35 tailings cores and six bed-sediment samples was undertaken to determine the concentrations of Ag, As, Cd, Cu, Pb,and Zn present in these materials. These elements are environmentally significant, in that they can be toxic to fish and/or the invertebrate organisms that constitute their food. A suite of one-inch cores of dispersed flotation-mill tailings and underlying premining material was taken from a large, flat area north of Basin Creek near the site of the Buckeye mine. Thirty-five core samples were taken and divided into 204 subsamples. The samples were analyzed by ICP-AES (inductively coupled plasma-atomic emission spectroscopy) using a mixed-acid digestion. Results of the core analyses show that the elements listed above are present at moderate to very high concentrations (arsenic to 63,000 ppm, silver to 290 ppm, cadmium to 370 ppm, copper to 4,800 ppm, lead to 93,000 ppm, and zinc to 23,000 ppm). Volume calculations indicate that an estimated 8,400 metric tons of contaminated material are present at the site. Six bed-sediment samples were also subjected to the mixed-acid total digestion, and a warm (50°C) 2M HCl-1% H2O2 leach and analyzed by ICP-AES. Results indicate that bed sediments of Basin Creek are only slightly impacted by past mining above the Buckeye-Enterprise complex, moderately impacted at the upper (eastern) end of the tailings area, and heavily impacted at the lower (western) end of the area and downstream. The metals are mostly contained in the 2M HCl-1% H2O2 leachable phase, which are the hydrous amorphous iron- and manganese-hydroxide coatings on detrital sediment particles.

Deconvolution of trace element (As, Cr, Mo, Th, U) sources and pathways to surface waters of a gold mining-influenced watershed.

PubMed

Grosbois, C; Schäfer, J; Bril, H; Blanc, G; Bossy, A

2009-03-01

The Upper Isle River (SW France) drains the second most productive gold-mining district of France. A high resolution survey during one hydrological year of As, Cl(-), Cr, Fe, Mn, Mo, SO(4)(2-), Th and U dissolved concentrations in surface water aimed to better understand pathways of trace element export to the river system downstream from the mining district. Dissolved concentrations of As (up to 35000 ng/L) and Mo (up to 292 ng/L) were about 3-fold higher than the regional dissolved background and showed a negative logarithmic relation with discharge. Dissolved concentrations of Cr (up to 483 ng/L), Th (up to 48 ng/L) and U (up to 184 ng/L) increased with discharge. Geochemical relationships between molar ratios in surface water, geochemical background as well as rain- and groundwater data were combined. The contrasting behavior of distinct element groups was explained by a scenario involving three seasonal components: (i) The high flow component is poorly concentrated in As and Mo but highly concentrated in Cr, Th, U. This has been attributed to diffuse sources such as water-soil interactions, atmospheric inputs, bedrock and bed sediment weathering. Although this component probably also includes a contribution by weathering of sulfide veins, this signal is masked by dilution. (ii) One low flow component presents high SO(4)(2-), Fe, As and Mo and moderate Cr, Th and U concentrations. This component has been attributed to point sources such as mine gallery effluents, mining waste weathering and groundwater inputs from natural and/or mining-induced sulfide oxidation in the ore deposit. (iii) A second low flow component showing high As plus Mo concentrations associated with very low SO(4)(2-), Fe, Cr, Th and U concentrations, probably reflects trace element scavenging by ferric oxyhydroxide formation in the adjacent aquifer. This is supported by the decrease of Fe, Cr, Th and U in surface waters. Flux estimates suggest contrasting element-specific impacts on annual dissolved fluxes. Runoff may account for the major part of annual dissolved As, Mo, Th and U fluxes in the Upper Isle River. Inputs related to sulfide oxidation respectively contributed approximately 30% and approximately 24% to annual As and Mo fluxes. The formation of ferric oxyhydroxides strongly retained Cr, Th and U during the low flow, limiting their dissolved concentrations in surface waters. If this process may eventually decrease As mobility, its impact on dissolved As concentrations in surface water may be limited or/and counterbalanced by As release during sulfide oxidation.

Mine blast injuries: ocular and social aspects

PubMed Central

Muzaffar, W.; Khan, M. D.; Akbar, M; Khan, M. D.; Malik, A. M.; Durrani, O.

2000-01-01

BACKGROUND/AIMS—Landmines have long been used in conventional warfare. These are antipersonnel mines which continue to injure people long after a ceasefire without differentiating between friend or foe, soldier or civilian, women or children. This study focuses on Afghan non-combatants engaged in mine clearing operations in Afghanistan in the aftermath of the Russo-Afghan war. The patterns and types of injuries seen are described and experiences in their management, ways, and means to prevent them, and recommendations for the rehabilitation of the affected individuals are given.
METHODS—It is a retrospective and analytical study of 84 patients aged 19-56 years who sustained mine blast injuries during mine clearing operations in Afghanistan from November 1992 to January 1996. The study was carried out at a military hospital with tertiary care facilities. The patients were divided into three groups on the basis of their injuries. Group 1 required only general surgical attention, group 2 sustained only ocular injuries, while group 3 had combined ocular and general injuries. Patients in groups 2 and 3 were treated in two phases. The first phase aimed at immediate restoration of the anatomy, while restoration of function wherever possible was done in subsequent surgical procedures in the second phase.
RESULTS—It was observed that 51 out of 84 patients (60.7%) had sustained ocular trauma of a variable degree as a result of the blasts. The mean age of the victims was 29 years and they were all male. A total of 91 eyes of 51 patients (89.2%) had been damaged. Bilaterality of damage was seen in 40 (78.4%) patients. Most, 34 (37.3%), eyes became totally blind (NPL). Only a few escaped with injury mild enough not to impair vision. Foreign bodies, small and multiple, were found in the majority of eyes; most, however, were found in the anterior segment, and posterior segment injuries were proportionally less.
CONCLUSIONS—The prevalence of blindness caused by mine blast injuries is quite high. The resulting psychosocial trauma to the patients and their families is tremendous and has not been adequately highlighted. These injuries are a great drain on the country's resources. Enforcement of preventive measures and the use of protective gear and sophisticated equipment by the mine clearing personnel would prove to be far more economical in terms of human life as well as medical and economic resources. There is also need for greater attention towards the establishment of support groups and rehabilitation programmes for these individuals.

 PMID:10837390

Oxic limestone drains for treatment of dilute, acidic mine drainage

USGS Publications Warehouse

Cravotta, Charles A.

1998-01-01

Limestone treatment systems can be effective for remediation of acidic mine drainage (AMD) that contains moderate concentrations of dissolved O2 , Fe3+ , or A13+ (1‐5 mg‐L‐1 ). Samples of water and limestone were collected periodically for 1 year at inflow, outflow, and intermediate points within underground, oxic limestone drains (OLDs) in Pennsylvania to evaluate the transport of dissolved metals and the effect of pH and Fe‐ and Al‐hydrolysis products on the rate of limestone dissolution. The influent was acidic and relatively dilute (pH <4; acidity < 90 mg‐L‐1 ) but contained 1‐4 mg‐L‐1 Of O2 , Fe3+ , A13+ , and Mn2+ . The total retention time in the OLDs ranged from 1.0 to 3.1 hours. Effluent remained oxic (02 >1 mg‐L‐1 ) but was near neutral (pH = 6.2‐7.0); Fe and Al decreased to less than 5% of influent concentrations. As pH increased near the inflow, hydrous Fe and Al oxides precipitated in the OLDs. The hydrous oxides, nominally Fe(OH)3 and AI(OH)3, were visible as loosely bound, orange‐yellow coatings on limestone near the inflow. As time elapsed, Fe(OH)3 and AI(OH)3 particles were transported downflow. During the first 6 months of the experiment, Mn 2+ was transported conservatively through the OLDs; however, during the second 6 months, concentrations of Mn in effluent decreased by about 50% relative to influent. The accumulation of hydrous oxides and elevated pH (>5) in the downflow part of the OLDs promoted sorption and coprecipitation of Mn as indicated by its enrichment relative to Fe in hydrous‐oxide particles and coatings on limestone. Despite thick (~1 mm) hydrous‐oxide coatings on limestone near the inflow, CaCO3 dissolution was more rapid near the inflow than at downflow points within the OLD where the limestone was not coated. The rate of limestone dissolution decreased with increased residence time, pH, and concentrations of Ca2+ and HCO3‐ and decreased PCO2. The following overall reaction shows alkalinity as an ultimate product of the iron hydrolysis reaction in an OLD:Fe2+ + 0.25 O2 +CaCO3 + 2.5 H2O --> Fe(OH)3 + 2 Ca2+ + 2 HCO3-where 2 moles of CaCO3 dissolve for each mole of Fe(OH)3 produced. Hence, in an OLD, rapidly dissolving limestone surfaces are not stable substrates for Fe(OH)3 attachment and armoring. Because overall efficiency is increased by combining neutralization and hydrolysis reactions, an OLD followed by a settling pond requires less land area than needed for a two‐stage treatment system consisting of an anoxic limestone drain an oxidation‐settling pond or wetland. To facilitate removal of hydrous‐oxide sludge, a perforated‐pipe subdrain can be installed within an OLD.

Chest Drain Fall-Out Rate According to Suturing Practices: A Retrospective Direct Comparison.

PubMed

Asciak, Rachelle; Addala, Dinesh; Karimjee, Juzer; Rana, Maaz Suhail; Tsikrika, Stamatoula; Hassan, Maged Fayed; Mercer, Rachel Mary; Hallifax, Robert John; Wrightson, John Matthew; Psallidas, Ioannis; Benamore, Rachel; Rahman, Najib Mahboob

2018-06-14

Chest drains often become displaced and require replacement, adding unnecessary risks to patients. Simple measures such as suturing of the drain may reduce fall-out rates; however, there is no direct data to demonstrate this and no standardized recommended practice that is evidence based. The study aimed to analyze the rate of chest drain fall out according to suturing practice. Retrospective analysis of all chest drain insertions (radiology and pleural teams) in 2015-2016. Details of chest drain fall out were collected from patient electronic records. Drain "fall out" was pre-hoc defined as the drain tip becoming dislodged outside the pleural cavity unintentionally before a clinical decision was taken to remove the drain. A total of 369 chest drains were inserted: sutured (n = 106, 28.7%; 44 male [41.5%], median age 74 [interquartile range (IQR) 21] years), and unsutured (n = 263, 71.3%; 139 male [52.9%], median age 68 [IQR 21] years). Of the sutured drains, 7 (6.6%) fell out after a mean of 3.3 days (SD 2.6) compared to 39 (14.8%; p = 0.04) unsutured drains falling out after a mean of 2.7 days (SD 2.0; p = 0.8). Within the limits of this retrospective analysis, these results -suggest that suturing of drains is associated with lower fall-out rates. © 2018 S. Karger AG, Basel.

Might digital drains speed up the time to thoracic drain removal?

PubMed

Afoke, Jonathan; Tan, Carol; Hunt, Ian; Zakkar, Mustafa

2014-07-01

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: might digital drains speed up the time to thoracic drain removal in terms of time till chest drain removal, hospital stay and overall cost? A total of 296 papers were identified as a result of the search as described below. Of these, five papers provided the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of the papers are tabulated. A literature search revealed that several single-centre prospective randomized studies have shown significantly earlier removal of chest drains with digital drains ranging between 0.8 and 2.1 days sooner. However, there was heterogeneity in studies in the management protocol of chest drains in terms of the use of suction, number of drains and assessment for drain removal. Some protocols such as routinely keeping drains irrespective of the presence of air leak or drain output may have skewed results. Differences in exclusion criteria and protocols for discharging home with portable devices may have biased results. Due to heterogeneity in the management protocol of chest drains, there is conflicting evidence regarding hospital stay. The limited data on cost suggest that there may be significantly lower postoperative costs in the digital drain group. All the studies were single-centre series generally including patients with good preoperative lung function tests. Further larger studies with more robust chest drain management protocols are required especially to assess length of hospital stay, cost and whether the results are applicable to a larger patient population. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Stream water quality in coal mined areas of the lower Cheat River Basin, West Virginia and Pennsylvania, during low-flow conditions, July 1997

USGS Publications Warehouse

Williams, Donald R.; Clark, Mary E.; Brown, Juliane B.

1999-01-01

IntroductionThe Cheat River Basin is in the Allegheny Plateau and Allegheny Mountain Sections of the Appalachian Plateau Physiographic Province (Fenneman, 1946) and is almost entirely within the state of West Virginia. The Cheat River drains an area of 1,422 square miles in Randolph, Tucker, Preston, and Monongalia Counties in West Virginia and Fayette County in Pennsylvania. From its headwaters in Randolph County, W.Va., the Cheat River flows 157 miles north to the Pennsylvania state line, where it enters the Monongahela River. The Cheat River drainage comprises approximately 19 percent of the total Monongahela River Basin. The Cheat River and streams within the Cheat River Basin are characterized by steep gradients, rock channels, and high flow velocities that have created a thriving white-water rafting industry for the area. The headwaters of the Cheat River contain some of the most pristine and aesthetic streams in West Virginia. The attraction to the area, particularly the lower part of the Cheat River Basin (the lower 412 square miles of the basin), has been suppressed because of poor water quality. The economy of the Lower Cheat River Basin has been dominated by coal mining over many decades. As a result, many abandoned deep and surface mines discharge untreated acid mine drainage (AMD), which degrades water quality, into the Cheat River and many of its tributary streams. Approximately 60 regulated mine-related discharges (West Virginia Department of Environmental Protection, 1996) and 185 abandoned mine sites (U.S. Office of Surface Mining, 1998) discharge treated and untreated AMD into the Cheat River and its tributaries.The West Virginia Department of Environmental Protection (WVDEP) Office of Abandoned Mine Lands and Reclamation (AML&R) has recently completed several AMD reclamation projects throughout the Cheat River Basin that have collectively improved the mainstem water quality. The AML&R office is currently involved in acquiring grant funds and designing treatment facilities for several additional AMD sites that adversely affect the Cheat River and its tributaries. To obtain the baseline water-quality information necessary to evaluate instream treatment and alternative methods for remediating AMD and its effects, the U.S. Geological Survey (USGS), in cooperation with the WVDEP, collected stream water samples at 111 sites throughout the Lower Cheat River Basin during low-flow conditions from July 16-18, 1997. The data also will provide information on stream water quality in areas affected by AMD and thus would point to priority areas of focus, such as the sources of the AMD. This report presents the results of analyses of the samples collected in July 1997 and describes a process for ranking of stream water-quality degradation as a guide to water-resource managers considering AMD remediation activities.

Charge plasma based source/drain engineered Schottky Barrier MOSFET: Ambipolar suppression and improvement of the RF performance

NASA Astrophysics Data System (ADS)

Kale, Sumit; Kondekar, Pravin N.

2018-01-01

This paper reports a novel device structure for charge plasma based Schottky Barrier (SB) MOSFET on ultrathin SOI to suppress the ambipolar leakage current and improvement of the radio frequency (RF) performance. In the proposed device, we employ dual material for the source and drain formation. Therefore, source/drain is divided into two parts as main source/drain and source/drain extension. Erbium silicide (ErSi1.7) is used as main source/drain material and Hafnium metal is used as source/drain extension material. The source extension induces the electron plasma in the ultrathin SOI body resulting reduction of SB width at the source side. Similarly, drain extension also induces the electron plasma at the drain side. This significantly increases the SB width due to increased depletion at the drain end. As a result, the ambipolar leakage current can be suppressed. In addition, drain extension also reduces the parasitic capacitances of the proposed device to improve the RF performance. The optimization of length and work function of metal used in the drain extension is performed to achieve improvement in device performance. Moreover, the proposed device makes fabrication simpler, requires low thermal budget and free from random dopant fluctuations.

Mercury and methylmercury related to historical mercury mining in three tributaries to Lake Berryessa, Putah Creek Watershed, California

NASA Astrophysics Data System (ADS)

Sparks, G. C.; Horner, T.; Cornwell, K.; Izzo, V.; Alpers, C. N.

2014-12-01

This study examined the relative contribution of total mercury (THg) and mono-methylmercury (MMHg) from upstream historical mercury-mining districts to Lake Berryessa, a reservoir with impaired water quality because of mercury. The third and fourth largest historical mercury-producing mining districts in California are within Lake Berryessa's three largest tributary watersheds: Pope, (Upper) Putah, and Knoxville-Eticuera Creeks. Downstream of the reservoir, Putah Creek drains into the Yolo Bypass, a major source of THg and MMHg to the Sacramento-San Joaquin Delta. Water samples were collected from October 2012 to May 2014 during 37 non-storm and 8 storm events along Pope, (Upper) Putah, and Knoxville-Eticuera Creeks and analyzed for field parameters (temperature, pH, specific conductance, dissolved oxygen, and turbidity). Additionally, water samples collected during five of the non-storm and storm events were analyzed for unfiltered THg and MMHg and total suspended solids (TSS). Discharge was measured during sampling to calculate instantaneous loads. More than 120 streambed sediment samples were collected to determine the spatial variation of THg and organic carbon content (loss on ignition). Across the watersheds, unfiltered THg (in water) samples ranged from 2.3 to 125 ng/L and unfiltered MMHg (in water) samples from 0.12 to 1.0 ng/L. Concentrations of THg ranged from less than 0.0001 to 122 mg/kg in streambed sediment. Tributary reaches with elevated mercury concentrations ("hot spots") are near or downstream of historical mercury mines and have: (1) strong positive correlations between THg (in water) or MMHg (in water) and TSS (R2> 0.88, n=5); (2) higher instantaneous loads of suspended sediment, THg and MMHg than reaches with low THg and MMHg concentrations; and (3) elevated sediment organic carbon content. Tributary reaches with weaker correlations among THg, MMHg, and TSS in unfiltered water may reflect non-mining sources of dissolved THg and MMHg, such as geothermal springs and groundwater influx from shallow aquifers. The importance of suspended particulate matter relative to THg and MMHg transport in the most contaminated stream reaches indicates that erosion control is likely to be a critical factor in successful remediation efforts in the Upper Putah Creek watershed.

Interaction of acid mine drainage with Ordinary Portland Cement blended solid residues generated from active treatment of acid mine drainage with coal fly ash.

PubMed

Gitari, Wilson M; Petrik, Leslie F; Key, David L; Okujeni, Charles

2011-01-01

Fly ash (FA) has been investigated as a possible treatment agent for Acid mine drainage (AMD) and established to be an alternative, cheap and economically viable agent compared to the conventional alkaline agents. However, this treatment option also leads to generation of solid residues (SR) that require disposal and one of the proposed disposal method is a backfill in coal mine voids. In this study, the interaction of the SR with AMD that is likely to be present in such backfill scenario was simulated by draining columns packed with SR and SR + 6% Ordinary Portland Cement (OPC) unsaturated with simulated AMD over a 6 month period. The evolving geochemistry of the liquid/solid (L/S) system was evaluated in-terms of the mineral phases likely or controlling contaminants attenuation at the different pH regimes generated. Stepwise acidification of the percolates was observed as the drainage progressed. Two pH buffer zones were observed (7.5-9 and 3-4) for SR and (11.2-11.3 and 3.5-4) for SR + 6% OPC. The solid residue cores (SR) appeared to have a significant buffering capacity, maintaining a neutral to slightly alkaline pH in the leachates for an extended period of time (97 days: L/S 4.3) while SR + 6% OPC reduced this neutralization capacity to 22 days (L/S 1.9). Interaction of AMD with SR or SR + 6% OPC generated alkaline conditions that favored precipitation of Fe, Al, Mn-(oxy) hydroxides, Fe and Ca-Al hydroxysulphates that greatly contributed to the contaminants removal. However, precipitation of these phases was restricted to the pH of the leachates remaining at neutral to circum-neutral levels. Backfill of mine voids with SR promises to be a feasible technology for the disposal of the SR but its success will greatly depend on the disposal scenario, AMD generated and the alkalinity generating potential of the SR. A disadvantage would be the possible re-dissolution of the precipitated phases at pH < 4 that would release the contaminants back to the water column. However extrapolation of this concept to a field scenario can greatly enhance beneficial application of fly ash (FA) and solid residues (SR) generated from treatment of AMD.

Drain Insertion in Chronic Subdural Hematoma: An International Survey of Practice.

PubMed

Soleman, Jehuda; Kamenova, Maria; Lutz, Katharina; Guzman, Raphael; Fandino, Javier; Mariani, Luigi

2017-08-01

To investigate whether, after the publication of grade I evidence that it reduces recurrence rates, the practice of drain insertion after burr-hole drainage of chronic subdural hematoma has changed. Further, we aimed to document various practice modalities concerning the insertion of a drain adopted by neurosurgeons internationally. We administered a survey to neurosurgeons worldwide with questions relating to the surgical treatment of chronic subdural hematoma, with an emphasis on their practices concerning the use of a drain. The preferred surgical technique was burr-hole drainage (89%). Most surgeons prefer to place a drain (80%), whereas in 56% of the cases the reason for not placing a drain was brain expansion after evacuation. Subdural drains are placed by 50% and subperiosteal drains by 27% of the responders, whereas 23% place primarily a subdural drain if possible and otherwise a subperiosteal drain. Three quarters of the responders leave the drain for 48 hours and give prophylactic antibiotic treatment, mostly a single-shot dose intraoperatively (70%). Routine postoperative computed tomography is done by 59% mostly within 24-48 hours after surgery (94%). Adjunct treatment to surgery rarely is used (4%). The publication of grade I evidence in favor of drain use influenced positively this practice worldwide. Some surgeons are still reluctant to insert a drain, especially when the subdural space is narrow after drainage of the hematoma. The insertion of a subperiosteal drain could be a good alternative solution. However, its outcome and efficacy must be evaluated in larger studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Novel Split Chest Tube Improves Post-Surgical Thoracic Drainage

PubMed Central

Olivencia-Yurvati, Albert H; Cherry, Brandon H; Gurji, Hunaid A; White, Daniel W; Newton, J Tyler; Scott, Gary F; Hoxha, Besim; Gourlay, Terence; Mallet, Robert T

2014-01-01

Objective Conventional, separate mediastinal and pleural tubes are often inefficient at draining thoracic effusions. Description We developed a Y-shaped chest tube with split ends that divide within the thoracic cavity, permitting separate intrathoracic placement and requiring a single exit port. In this study, thoracic drainage by the split drain vs. that of separate drains was tested. Methods After sternotomy, pericardiotomy, and left pleurotomy, pigs were fitted with separate chest drains (n=10) or a split tube prototype (n=9) with internal openings positioned in the mediastinum and in the costo-diaphragmatic recess. Separate series of experiments were conducted to test drainage of D5W or 0.58 M sucrose, an aqueous solution with viscosity approximating that of plasma. One litre of fluid was infused into the thorax, and suction was applied at −20 cm H2O for 30 min. Results When D5W was infused, the split drain left a residual volume of 53 ± 99 ml (mean value ± SD) vs. 148 ± 120 for the separate drain (P=0.007), representing a drainage efficiency (i.e. drained vol/[drained + residual vol]) of 95 ± 10% vs. 86 ± 12% for the separate drains (P = 0.011). In the second series, the split drain evacuated more 0.58 M sucrose in the first minute (967 ± 129 ml) than the separate drains (680 ± 192 ml, P<0.001). By 30 min, the split drain evacuated a similar volume of sucrose vs. the conventional drain (1089 ± 72 vs. 1056 ± 78 ml; P = 0.5). Residual volume tended to be lower (25 ± 10 vs. 62 ± 72 ml; P = 0.128) and drainage efficiency tended to be higher (98 ± 1 vs. 95 ± 6%; P = 0.111) with the split drain vs. conventional separate drains. Conclusion The split chest tube drained the thoracic cavity at least as effectively as conventional separate tubes. This new device could potentially alleviate postoperative complications. PMID:25478289

Novel Split Chest Tube Improves Post-Surgical Thoracic Drainage.

PubMed

Olivencia-Yurvati, Albert H; Cherry, Brandon H; Gurji, Hunaid A; White, Daniel W; Newton, J Tyler; Scott, Gary F; Hoxha, Besim; Gourlay, Terence; Mallet, Robert T

2014-01-01

Conventional, separate mediastinal and pleural tubes are often inefficient at draining thoracic effusions. We developed a Y-shaped chest tube with split ends that divide within the thoracic cavity, permitting separate intrathoracic placement and requiring a single exit port. In this study, thoracic drainage by the split drain vs. that of separate drains was tested. After sternotomy, pericardiotomy, and left pleurotomy, pigs were fitted with separate chest drains (n=10) or a split tube prototype (n=9) with internal openings positioned in the mediastinum and in the costo-diaphragmatic recess. Separate series of experiments were conducted to test drainage of D5W or 0.58 M sucrose, an aqueous solution with viscosity approximating that of plasma. One litre of fluid was infused into the thorax, and suction was applied at -20 cm H2O for 30 min. When D5W was infused, the split drain left a residual volume of 53 ± 99 ml (mean value ± SD) vs. 148 ± 120 for the separate drain (P=0.007), representing a drainage efficiency (i.e. drained vol/[drained + residual vol]) of 95 ± 10% vs. 86 ± 12% for the separate drains (P = 0.011). In the second series, the split drain evacuated more 0.58 M sucrose in the first minute (967 ± 129 ml) than the separate drains (680 ± 192 ml, P<0.001). By 30 min, the split drain evacuated a similar volume of sucrose vs. the conventional drain (1089 ± 72 vs. 1056 ± 78 ml; P = 0.5). Residual volume tended to be lower (25 ± 10 vs. 62 ± 72 ml; P = 0.128) and drainage efficiency tended to be higher (98 ± 1 vs. 95 ± 6%; P = 0.111) with the split drain vs. conventional separate drains. The split chest tube drained the thoracic cavity at least as effectively as conventional separate tubes. This new device could potentially alleviate postoperative complications.

Diel cycles in dissolved metal concentrations in streams: Occurrence and possible causes

USGS Publications Warehouse

Nimick, David A.; Gammons, Christopher H.; Cleasby, Thomas E.; Madison, James P.; Skaar, Don; Brick, Christine M.

2003-01-01

Substantial diel (24‐hour) cycles in dissolved (0.1‐μm filtration) metal concentrations were observed during low flow for 18 sampling episodes at 14 sites on 12 neutral and alkaline streams draining historical mining areas in Montana and Idaho. At some sites, concentrations of Cd, Mn, Ni, and Zn increased as much as 119, 306, 167, and 500%, respectively, from afternoon minimum values to maximum values shortly after sunrise. Arsenic concentrations exhibited the inverse temporal pattern with increases of up to 54%. Variations in Cu concentrations were small and inconsistent. Diel metal cycles are widespread and persistent, occur over a wide range of metal concentrations, and likely are caused primarily by instream geochemical processes. Adsorption is the only process that can explain the inverse temporal patterns of As and the divalent metals. Diel metal cycles have important implications for many types of water‐quality studies and for understanding trace‐metal mobility.

Numerical modeling of consolidation processes in hydraulically deposited soils

NASA Astrophysics Data System (ADS)

Brink, Nicholas Robert

Hydraulically deposited soils are encountered in many common engineering applications including mine tailing and geotextile tube fills, though the consolidation process for such soils is highly nonlinear and requires the use of advanced numerical techniques to provide accurate predictions. Several commercially available finite element codes poses the ability to model soil consolidation, and it was the goal of this research to assess the ability of two of these codes, ABAQUS and PLAXIS, to model the large-strain, two-dimensional consolidation processes which occur in hydraulically deposited soils. A series of one- and two-dimensionally drained rectangular models were first created to assess the limitations of ABAQUS and PLAXIS when modeling consolidation of highly compressible soils. Then, geotextile tube and TSF models were created to represent actual scenarios which might be encountered in engineering practice. Several limitations were discovered, including the existence of a minimum preconsolidation stress below which numerical solutions become unstable.

3. DRAINING & DRYING BUILDING, REINFORCED CONCRETE MUSHROOM COLUMNS WITH ...

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

3. DRAINING & DRYING BUILDING, REINFORCED CONCRETE MUSHROOM COLUMNS WITH DROP PANELS SUPPORTING DRAINING BINS (IRON VALVES OF DRAINING BINS ARE EMBEDDED IN THE CEILING), VIEW LOOKING WEST - Mill "C" Complex, Sand Draining & Drying Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

Evisceration of Appendix through the Drain Site: A Rare Case Report.

PubMed

Ravishankaran, Praveen; Rajamani, A

2013-06-01

Placing a drain after surgery is a usual procedure in any emergency abdominal operation. The drain is removed as soon as its purpose of draining the intraabdominal collection in served. Evisceration of intraabdominal organs through the drain site is a rare occurance. This case report is about an 12 year old girl who was admitted with blunt trauma abdomen. After completion of emergency laparotomy a drain was placed in the right lower quadrant. When the drain was removed on the 6th post operative day, the appendix eviscerated out of the drain site. The wound was extended a little and an appendectomy was done. This case is presented for its rarity as only two similar instances have been reported in literature so far.

A forgotten retained drain inside a knee for 10 years: A case report.

PubMed

Koaban, Saeed; Alatassi, Raheef; Alogayyel, Nawaf

2018-05-29

Surgical drains are inserted into the wound after an arthroscopic knee procedure mainly to decrease fluid collection after the operation. The use of postoperative surgical drains remains controversial. This report presents a rare case of a forgotten retained drain that was accidentally found inside a knee 10 years after an arthroscopic procedure. The drain was removed without any complications. A retained and broken drain during removal is a very rare and preventable complication that can be stressful for both the patient and surgeon. Most of the literature supports that retained drains in the soft tissues do not affect long-term outcomes, but if the drain fragment is in the intra-articular area, it might cause complications. Furthermore, there are several preventive measures to avoid retained surgical drains. By reporting this case of a forgotten drain retained inside a knee for approximately 10 years, we aim to illustrate the potential risk of leaving a drain inside the joint following an arthroscopic procedure. Furthermore, we advise that surgeons maintain a high index of suspicion for iatrogenic complications when a patient continues to complain about unexplained pain at the surgical site. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Concentration trends for lead and calcium-normalized lead in fish fillets from the Big River, a mining-contaminated stream in southeastern Missouri USA

USGS Publications Warehouse

Schmitt, Christopher J.; McKee, Michael J.

2016-01-01

Lead (Pb) and calcium (Ca) concentrations were measured in fillet samples of longear sunfish (Lepomis megalotis) and redhorse suckers (Moxostoma spp.) collected in 2005–2012 from the Big River, which drains a historical mining area in southeastern Missouri and where a consumption advisory is in effect due to elevated Pb concentrations in fish. Lead tends to accumulated in Ca-rich tissues such as bone and scale. Concentrations of Pb in fish muscle are typically low, but can become elevated in fillets from Pb-contaminated sites depending in part on how much bone, scale, and skin is included in the sample. We used analysis-of-covariance to normalize Pb concentration to the geometric mean Ca concentration (415 ug/g wet weight, ww), which reduced variation between taxa, sites, and years, as was the number of samples that exceeded Missouri consumption advisory threshold (300 ng/g ww). Concentrations of Pb in 2005–2012 were lower than in the past, especially after Ca-normalization, but the consumption advisory is still warranted because concentrations were >300 ng/g ww in samples of both taxa from contaminated sites. For monitoring purposes, a simple linear regression model is proposed for estimating Ca-normalized Pb concentrations in fillets from Pb:Ca molar ratios as a way of reducing the effects of differing preparation methods on fillet Pb variation.

Concentration Trends for Lead and Calcium-Normalized Lead in Fish Fillets from the Big River, a Mining-Contaminated Stream in Southeastern Missouri USA.

PubMed

Schmitt, Christopher J; McKee, Michael J

2016-11-01

Lead (Pb) and calcium (Ca) concentrations were measured in fillet samples of longear sunfish (Lepomis megalotis) and redhorse suckers (Moxostoma spp.) collected in 2005-2012 from the Big River, which drains a historical mining area in southeastern Missouri and where a consumption advisory is in effect due to elevated Pb concentrations in fish. Lead tends to accumulated in Ca-rich tissues such as bone and scale. Concentrations of Pb in fish muscle are typically low, but can become elevated in fillets from Pb-contaminated sites depending in part on how much bone, scale, and skin is included in the sample. We used analysis-of-covariance to normalize Pb concentration to the geometric mean Ca concentration (415 ug/g wet weight, ww), which reduced variation between taxa, sites, and years, as was the number of samples that exceeded Missouri consumption advisory threshold (300 ng/g ww). Concentrations of Pb in 2005-2012 were lower than in the past, especially after Ca-normalization, but the consumption advisory is still warranted because concentrations were >300 ng/g ww in samples of both taxa from contaminated sites. For monitoring purposes, a simple linear regression model is proposed for estimating Ca-normalized Pb concentrations in fillets from Pb:Ca molar ratios as a way of reducing the effects of differing preparation methods on fillet Pb variation.

Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

NASA Astrophysics Data System (ADS)

Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

2018-01-01

Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

CZO perspective in Central Africa : The Lopé watershed, Lopé National Park, Ogooué River basin, Gabon.

NASA Astrophysics Data System (ADS)

Braun, J. J.; Jeffery, K.; Koumba Pambo, A. F.; Paiz, M. C.; Richter, D., Jr.; John, P.; Jerome, G.

2015-12-01

Critical Zone Observatories (CZO) in equatorial regions are seldom (see e. g. http://www.czen.org/, USA and http://rnbv.ipgp.fr/, France). The equatorial zone of Central Africa is almost free of them with the exception of the CZO of the Upper Nyong river basin (organic-rich river on the lateritic plateau of South Cameroon; SO BVET, http://bvet.omp.obs-mip.fr/). On both sides of the Equator line, the Ogooué River Basin (215,000 km2) stretches on about 80% of the total area of Gabon and drains various geological and morpho-pedological contexts and feeds the sedimentation areas of the Central African passive margin (Guillochaux et al., 2014). The Upper Ogooué (up to Lambaréné) drains the stepped planation surface of the Congo craton while the Lower Ogooué drains Mesozoic and Cenozoic sedimentary terrains. The climate is equatorial (Pmean = 2500 mm/yr; Tmean = 26 °; %humidity > 80%). Continuous hydro-climatic chronicles exist for the period 1953-1974 (managed by ORSTOM, now IRD). The runoff at Lambaréné (92% of the basin area) is very high (714 mm/yr). With a rural density of 1 inhabitant/km2, it is one of the last largely pristine tropical forested ecosystems on the Planet. In addition, the basin will be, in the coming decades, the theatre of important anthropogenic changes (dams, agriculture, mining, urbanisation, …). However, a conservation plan with an ambitious sustainable development policy is set up. This plan articulates the environmental issues related to the emergence of the country. Because of these characteristics, the basin offers ideal conditions for studying the changes in equatorial region of hydro-climate, weathering/erosion regimes and regolith production based on morpho-pedological contexts and associated physical, chemical and biological processes. It is thus germane to launch an integrated CZO initiative at both regional scale and local scale. At the regional scale, we plan to reactivate some of the hydro-climatic stations located on the planation surface (Franceville, Ayem, and Lambaréné). At the local scale, we plan to set up a small experimental watershed on the Lopé stream draining the northern part of the Lopé National Park, which is covered by a mosaic of forest and savannah. The Ogooué CZO will be highly complementary to the Nyong CZO, Cameroon, and a major asset for the international community.

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

21 CFR 868.5995 - Tee drain (water trap).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

21 CFR 868.5995 - Tee drain (water trap).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

21 CFR 868.5995 - Tee drain (water trap).

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

21 CFR 868.5995 - Tee drain (water trap).

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

A mathematical model to optimize the drain phase in gravity-based peritoneal dialysis systems.

PubMed

Akonur, Alp; Lo, Ying-Cheng; Cizman, Borut

2010-01-01

Use of patient-specific drain-phase parameters has previously been suggested to improve peritoneal dialysis (PD) adequacy. Improving management of the drain period may also help to minimize intraperitoneal volume (IPV). A typical gravity-based drain profile consists of a relatively constant initial fast-flow period, followed by a transition period and a decaying slow-flow period. That profile was modeled using the equation VD(t) = (V(D0) - Q(MAX) x t) xphi + (V(D0) x e(-alphat)) x (1 - phi), where V(D)(t) is the time-dependent dialysate volume; V(D0), the dialysate volume at the start of the drain; Q(MAX), the maximum drain flow rate; alpha, the exponential drain constant; and phi, the unit step function with respect to the flow transition. We simulated the effects of the assumed patient-specific maximum drain flow (Q(MAX)) and transition volume (psi), and the peritoneal volume percentage when transition occurs,for fixed device-specific drain parameters. Average patient transport parameters were assumed during 5-exchange therapy with 10 L of PD solution. Changes in therapy performance strongly depended on the drain parameters. Comparing 400 mL/85% with 200 mL/65% (Q(MAX/psi), drain time (7.5 min vs. 13.5 min) and IPV (2769 mL vs. 2355 mL) increased when the initial drain flow was low and the transition quick. Ultrafiltration and solute clearances remained relatively similar. Such differences were augmented up to a drain time of 22 minutes and an IPV of more than 3 L when Q(MAX) was 100 mL/min. The ability to model individual drain conditions together with water and solute transport may help to prevent patient discomfort with gravity-based PD. However, it is essential to note that practical difficulties such as displaced catheters and obstructed flow paths cause variability in drain characteristics even for the same patient, limiting the clinical applicability of this model.

Bacterial diversity of floor drain biofilms and drain waters in a Listeria monocytogenes contaminated food processing environment.

PubMed

Dzieciol, Monika; Schornsteiner, Elisa; Muhterem-Uyar, Meryem; Stessl, Beatrix; Wagner, Martin; Schmitz-Esser, Stephan

2016-04-16

Sanitation protocols are applied on a daily basis in food processing facilities to prevent the risk of cross-contamination with spoilage organisms. Floor drain water serves along with product-associated samples (slicer dust, brine or cheese smear) as an important hygiene indicator in monitoring Listeria monocytogenes in food processing facilities. Microbial communities of floor drains are representative for each processing area and are influenced to a large degree by food residues, liquid effluents and washing water. The microbial communities of drain water are steadily changing, whereas drain biofilms provide more stable niches. Bacterial communities of four floor drains were characterized using 16S rRNA gene pyrosequencing to better understand the composition and exchange of drain water and drain biofilm communities. Furthermore, the L. monocytogenes contamination status of each floor drain was determined by applying cultivation-independent real-time PCR quantification and cultivation-dependent detection according to ISO11290-1. Pyrosequencing of 16S rRNA genes of drain water and drain biofilm bacterial communities yielded 50,611 reads, which were clustered into 641 operational taxonomic units (OTUs), affiliated to 16 phyla dominated by Proteobacteria, Firmicutes and Bacteroidetes. The most abundant OTUs represented either product- (Lactococcus lactis) or fermentation- and food spoilage-associated phylotypes (Pseudomonas mucidolens, Pseudomonas fragi, Leuconostoc citreum, and Acetobacter tropicalis). The microbial communities in DW and DB samples were distinct in each sample type and throughout the whole processing plant, indicating the presence of indigenous specific microbial communities in each processing compartment. The microbiota of drain biofilms was largely different from the microbiota of the drain water. A sampling approach based on drain water alone may thus only provide reliable information on planktonic bacterial cells but might not allow conclusions on the bacterial composition of the microbiota in biofilms. Copyright © 2016. Published by Elsevier B.V.

[Outpatient Drain Management in Patients with Clinically Relevant Postoperative Pancreatic Fistula (CR-POPF) - Current Status in Germany].

PubMed

Hempel, Sebastian; Püttmann, Pamela; Kahlert, Christoph; Seifert, Lena; Mees, Sören Torge; Welsch, Thilo; Weitz, Jürgen; Distler, Marius

2018-06-01

Postoperative pancreatic fistula (POPF) is a common complication after pancreatic surgery and is associated with extended hospitalisation, increased medical costs, and reduced quality of life. The aim of the present study was to assess the treatment of POPF in Germany, with a special focus on outpatient drain management in patients with clinically relevant POPF (CR-POPF). A questionnaire evaluating postoperative management once a CR-POPF is diagnosed - especially focusing on ambulatory drain management - was developed and sent to 211 German hospitals performing > 12 pancreatic operations per year. Statistical analysis was carried out using SPSS 21. The final response rate was 62% (n = 131). Outpatient drainage management is performed by most of the responding hospitals (n = 100, 76.3%). However, 30% of hospitals (n = 40) perform outpatient treatment only in 5% of their cases with clinically relevant POPF. There was no correlation between case load of the pancreatic centres and frequency of outpatient drain management. In general, discharge criteria for patients with drained POPF (n = 98, 74.8%), the drain management itself (n = 95, 72.5%) and criteria for drain removal (n = 74, 56.5%) are not standardised but made individually. In centres with standardised drain management criteria for drain removal, these criteria were drain volume < 20 ml (29.8%), no fluid collection (25.2%), no elevation of drain amylase/lipase (25.2%) and no specific symptoms (22.1%). This is the first survey in Germany evaluating outpatient drain management in patients with CR-POPF. Although the data in the literature are rare, the majority of German pancreatic surgeons perform outpatient drain management. However, discharge criteria, outpatient care and drain removal are standardised in only the minority of centres. Therefore, we recommend the evaluation of discharge criteria and a management algorithm for patients with drained CR-POPF to improve the perioperative course. Georg Thieme Verlag KG Stuttgart · New York.

Drivers of variability in tree transpiration in a Boreal Black Spruce Forest Chronosequence

NASA Astrophysics Data System (ADS)

Angstmann, J. L.; Ewers, B. E.; Kwon, H.

2009-12-01

Boreal forests are of particular interest in climate change studies because of their large land area and ability to sequester and store carbon, which is controlled by water availability. Heterogeneity of these forests is predicted to increase with climate change through the impact of more frequent wildfires, warmer, longer growing seasons, and potential drainage of forested wetlands. This study aims to quantify the influence of stand age, drainage condition, and species on tree transpiration and its drivers in a central Canadian black spruce boreal forest. Heat dissipation sensors were installed in 113 trees (69 Picea mariana (black spruce), 25 Populus tremuloides (trembling aspen), and 19 Pinus banksiana (jack pine) at four stand ages, each containing a well- and poorly-drained site over three growing seasons (2006-2008). Sap flux per unit xylem area, JS, was expressed as transpiration per unit ground area, EC, and transpiration per unit leaf area, EL, using site- and species-specific allometry to obtain sapwood area (AS)and leaf area(AL)per unit ground area. Well-drained, younger Picea mariana daily JS was 47-64% greater than the older well-drained burn ages and younger poorly-drained stands were 64-68% greater than the two oldest poorly-drained stands. Daily EL in the well-drained Picea mariana stands was on average 12-33% higher in younger stand than in the two oldest stands whereas young, poorly-drained Picea mariana had 71% greater daily EL than the older stands. Well-drained Picea mariana trees had 52% higher daily EC than older trees and poorly-drained Picea mariana in the 1964 burn had 42-81% higher daily EC than the oldest stands. Populus tremuloides located in the two youngest stands had daily JS 38-58% greater rates than the 1930 burn, whereas daily EL and EC had no distint differences due to high interannual variability. Pinus banksiana experienced 21-33% greater daily JS in the 1989 burn than in the older 1964 burn for well- and poorly-drained sites. Poorly-drained Pinus banksiana trees from the older 1964 burn had 23-48% greater daily EL and 26-39% higher daily EC than the 1989 burn. Poorly-drained Picea mariana had 17-31% higher daily JS than the well-drained sites. Poorly-drained Picea mariana had 29-58% higher daily EL 42-50% higher daily EC than the well-drained trees. Poorly-drained Pinus banksiana on average had 27-28% higher daily JS than well-drained trees. Poorly-drained Pinus banskiana had 23.25% higher daily EL than well-drained trees and daily EC 32-67% lower than the well-drained trees. Drivers of these differences include midday leaf water potential, AS, and AL.

A screening-level assessment of lead, cadmium, and zinc in fish and crayfish from northeastern Oklahoma, USA

USGS Publications Warehouse

Schmitt, C.J.; Brumbaugh, W.G.; Linder, G.L.; Hinck, J.E.

2006-01-01

The objective of this study was to evaluate potential human and ecological risks associated with metals in fish and crayfish from mining in the Tri-States Mining District (TSMD). Crayfish (Orconectes spp.) and fish of six frequently consumed species (common carp, Cyprinus carpio; channel catfish, Ictalurus punctatus; flathead catfish, Pylodictis olivaris; largemouth bass, Micropterus salmoides; spotted bass, M. punctulatus; and white crappie, Pomoxis annularis) were collected in 2001-2002 from the Oklahoma waters of the Spring River (SR) and Neosho River (NR), which drain the TSMD. Samples from a mining-contaminated site in eastern Missouri and from reference sites were also analyzed. Individual fish were prepared for human consumption in the manner used locally by Native Americans (headed, eviscerated, and scaled) and analyzed for lead, cadmium, and zinc. Whole crayfish were analyzed as composite samples of 5-60 animals. Metals concentrations were typically higher in samples from sites most heavily affected by mining and lowest in reference samples. Within the TSMD, most metals concentrations were higher at sites on the SR than on the NR and were typically highest in common carp and crayfish than in other taxa. Higher concentrations and greater risk were associated with fish and crayfish from heavily contaminated SR tributaries than the SR or NR mainstems. Based on the results of this and previous studies, the human consumption of carp and crayfish could be restricted based on current criteria for lead, cadmium, and zinc, and the consumption of channel catfish could be restricted due to lead. Metals concentrations were uniformly low in Micropterus spp. and crappie and would not warrant restriction, however. Some risk to carnivorous avian wildlife from lead and zinc in TSMD fish and invertebrates was also indicated, as was risk to the fish themselves. Overall, the wildlife assessment is consistent with previously reported biological effects attributed to metals from the TSMD. The results demonstrate the potential for adverse effects in fish, wildlife, and humans and indicate that further investigation of human health and ecological risks, to include additional exposure pathways and endpoints, is warranted. ?? Springer Science+Business Media B.V. 2006.

Major and trace-element analyses of acid mine waters in the Leviathan Mine drainage basin, California/Nevada; October, 1981 to October, 1982

USGS Publications Warehouse

Ball, J.W.; Nordstrom, D. Kirk

1985-01-01

Water issuing from the inactive Leviathan open-pit sulfur mine has caused serious degradation of the water quality in the Leviathan/Bryant Creek drainage basin which drains into the East Fork of the Carson River. As part of a pollution abatement project of the California Regional Water Quality Control Board, the U.S. Geological Survey collected hydrologic and water quality data for the basin during 1981-82. During this period a comprehensive sampling survey was completed to provide information on trace metal attenuation during downstream transport and to provide data for interpreting geochemical processes. This report presents the analytical results from this sampling survey. Sixty-seven water samples were filtered and preserved on-site at 45 locations and at 3 different times. Temperature, discharge, pH, and Eh and specific conductance were measured on-site. Concentrations of 37 major and trace constituents were determined later in the laboratory on preserved samples. The quality of the analyses was checked by using two or more techniques to determine the concentrations including d.c.-argon plasma emission spectrometry (DCP), flame and flameless atomic absorption spectrophotometry, UV-visible spectrophotometry, hydride-generation atomic absorption spectrophotometry and ion chromatography. Additional quality control was obtained by comparing measured to calculated conductance, comparing measured to calculated Eh (from Fe-2 +/Fe-3+ determinations), charge balance calculations and mass balance calculations for conservative constituents at confluence points. Leviathan acid mine waters contain mg/L concentrations of As, Cr, Co, Cu, Mn, Ni, T1, V and Zn, and hundreds to thousands of mg/L concentrations of Al, Fe, and sulfate at pH values as low as 1.8. Other elements including Ba, B, Be, Bi, Cd , Mo, Sb, Se and Te are elevated above normal background concentrations and fall in the microgram/L range. The chemical and 34 S/32 S isotopic analyses demonstrate that these acid waters are derived from pyrite oxidation and not from the oxidation of elemental sulfur. (Author 's abstract)

Controlling the ambipolarity and improvement of RF performance using Gaussian Drain Doped TFET

NASA Astrophysics Data System (ADS)

Nigam, Kaushal; Gupta, Sarthak; Pandey, Sunil; Kondekar, P. N.; Sharma, Dheeraj

2018-05-01

Ambipolar conduction in tunnel field-effect transistors (TFETs) has been occurred as an inherent issue due to drain-channel tunneling. It makes TFET less efficient and restricts its application in complementary digital circuits. Therefore, this manuscript reports the application of Gaussian doping profile on nanometer regime silicon channel TFETs to completely eliminate the ambipolarity. For this, Gaussian doping is used in the drain region of conventional gate-drain overlap TFET to control the tunneling of electrons from the valence band of channel to the conduction band of drain. As a result, barrier width at the drain/channel junction increases significantly leading to the suppression of an ambipolar current even when higher doping concentration (1 ? 10 ? cm ?) is considered in the drain region. However, significant improvement in terms of RF figure-of-merits such as cut-off frequency (f ?), gain bandwidth product (GBW), and gate-to-drain capacitance (C ?) is achieved with Gaussian doped gate on drain overlap TFET as compared to its counterpart TFET.

Effect of abdominopelvic abscess drain size on drainage time and probability of occlusion

PubMed Central

Rotman, Jessica A.; Getrajdman, George I.; Maybody, Majid; Erinjeri, Joseph P.; Yarmohammadi, Hooman; Sofocleous, Constantinos T.; Solomon, Stephen B.; Boas, F. Edward

2016-01-01

Background The purpose of this study is to determine whether larger abdominopelvic abscess drains reduce the time required for abscess resolution, or the probability of tube occlusion. Methods 144 consecutive patients who underwent abscess drainage at a single institution were reviewed retrospectively. Results: Larger initial drain size did not reduce drainage time, drain occlusion, or drain exchanges (p>0.05). Subgroup analysis did not find any type of collection that benefitted from larger drains. A multivariate model predicting drainage time showed that large collections (>200 ml) required 16 days longer drainage time than small collections (<50 ml). Collections with a fistula to bowel required 17 days longer drainage time than collections without a fistula. Initial drain size and the viscosity of the fluid in the collection had no significant effect on drainage time in the multivariate model. Conclusions 8 F drains are adequate for initial drainage of most serous and serosanguineous collections. 10 F drains are adequate for initial drainage of most purulent or bloody collections. PMID:27634422

Drain tube migration into the anastomotic site of an esophagojejunostomy for gastric small cell carcinoma: short report

PubMed Central

2010-01-01

Background Intraluminal migration of a drain through an anastomotic site is a rare complication of gastric surgery. Case Presentation We herein report the intraluminal migration of a drain placed after a lower esophagectomy and total gastrectomy with Roux-en-Y anastomosis for gastric small cell carcinoma. Persistent drainage was noted 1 month after surgery, and radiographic studies were consistent with drain tube migration. Endoscopy revealed the drain had migrated into the esophagojejunostomy anastomotic site. The drain was removed from outside of abdominal wound while observing the anastomotic site endoscopically. The patient was treated with suction via a nasogastric tube drain for 5 days, and thereafter had an uneventful recovery. Conclusions Though drain tube migration is a rare occurrence, it should be considered in patients with persistent drainage who have undergone gastric surgery. PMID:20492665

Drain tube migration into the anastomotic site of an esophagojejunostomy for gastric small cell carcinoma: short report.

PubMed

Lai, Peng-Sheng; Lo, Chiao; Lin, Long-Wei; Lee, Po-Chu

2010-05-21

Intraluminal migration of a drain through an anastomotic site is a rare complication of gastric surgery. We herein report the intraluminal migration of a drain placed after a lower esophagectomy and total gastrectomy with Roux-en-Y anastomosis for gastric small cell carcinoma. Persistent drainage was noted 1 month after surgery, and radiographic studies were consistent with drain tube migration. Endoscopy revealed the drain had migrated into the esophagojejunostomy anastomotic site. The drain was removed from outside of abdominal wound while observing the anastomotic site endoscopically. The patient was treated with suction via a nasogastric tube drain for 5 days, and thereafter had an uneventful recovery. Though drain tube migration is a rare occurrence, it should be considered in patients with persistent drainage who have undergone gastric surgery.

Drain site evisceration of fallopian tube, another reason to discourage abdominal drain: report of a case and brief review of literature.

PubMed

Saini, Pradeep; Faridi, M S; Agarwal, Nitin; Gupta, Arun; Kaur, Navneet

2012-04-01

Placement of a drain following abdominal surgery is common despite a lack of convincing evidence in the current literature to support this practice. The use of intra-abdominal drain is associated with many potential and serious complications. We report a drain site evisceration of the right fallopian tube after the removal of an intra-abdominal drain. The drain was placed in the right iliac fossa in a patient who underwent a lower segment Caesarean section (LSCS) for meconium liquor with fetal distress. The Pfannenstiel incision made for LSCS was reopened and the protruding inflamed fimbrial end of the right fallopian tube was excised. The patient made an uneventful recovery. Routine intra-abdominal prophylactic drain following an abdominal surgery including LSCS should be discouraged.

An elevated source/drain-on-insulator structure to maximize the intrinsic performance of extremely scaled MOSFETs

NASA Astrophysics Data System (ADS)

Zhang, Zhikuan; Zhang, Shengdong; Feng, Chuguang; Chan, Mansun

2003-10-01

In this paper, a source/drain structure separated from the silicon substrate by oxide isolation is fabricated and studied. The source/drain diffusion regions are connected to the shallow source/drain extension through a smaller opening defined by a double spacer process. Experimental results indicate that the source/drain on insulator significantly reduces the parasitic capacitance. Further optimization by simulation indicates a reduction of series resistance and band-to-band drain leakage at off-state can be achieved in extremely scaled devices. Compared with the conventional planner source/drain structure, the reduction of parasitic capacitance and series resistance can be as much as 80% and 30% respectively.

Prospective Validation of Optimal Drain Management "The 3 × 3 Rule" after Liver Resection.

PubMed

Mitsuka, Yusuke; Yamazaki, Shintaro; Yoshida, Nao; Masamichi, Moriguchi; Higaki, Tokio; Takayama, Tadatoshi

2016-09-01

We previously established an optimal postoperative drain management rule after liver resection (i.e., drain removal on postoperative day 3 if the drain fluid bilirubin concentration is <3 mg/dl) from the results of 514 drains of 316 consecutive patients. This test set predicts that 274 of 316 patients (87.0 %) will be safely managed without adverse events when drain management is performed without deviation from the rule. To validate the feasibility of our rule in recent time period. The data from 493 drains of 274 consecutive patients were prospectively collected. Drain fluid volumes, bilirubin levels, and bacteriological cultures were measured on postoperative days (POD) 1, 3, 5, and 7. The drains were removed according to the management rule. The achievement rate of the rule, postoperative adverse events, hospital stay, medical costs, and predictive value for reoperation according to the rule were validated. The rule was achieved in 255 of 274 (93.1 %) patients. The drain removal time was significantly shorter [3 days (1-30) vs. 7 (2-105), p < 0.01], drain fluid infection was less frequent [4 patients (1.5 %) vs. 58 (18.4 %), p < 0.01], postoperative hospital stay was shorter [11 days (6-73) vs. 16 (9-59), p = 0.04], and medical costs were decreased [1453 USD (968-6859) vs. 1847 (4667-9498), p < 0.01] in the validation set compared with the test set. Five patients who required reoperation were predicted by the drain-based information and treated within 2 days after operation. Our 3 × 3 rule is clinically feasible and allows for the early removal of the drain tube with minimum infection risk after liver resection.

Assessment of the use of selected chemical and microbiological constituents as indicators of wastewater in curtain drains from home sewage-treatment systems in Medina County, Ohio

USGS Publications Warehouse

Dumouchelle, Denise H.

2006-01-01

Many home sewage-treatment systems (HSTS) in Ohio use curtain or perimeter drains to depress the level of the subsurface water in and around the systems. These drains could possibly intercept partially untreated wastewater and release potential pathogens to ground-water and surface-water bodies. The quality of water in curtain drains from two different HSTS designs in Medina County, Ohio, was investigated using several methods. Six evaporation-transpiration-absorption (ETA) and five leach-line (LL) systems were investigated by determining nutrient concentrations, chloride/bromide ratios (Cl/Br), Escherichia coli (E. coli ) concentrations, coliphage genotyping, and genetic fingerprinting of E. coli. Water samples were collected at 11 sites and included samples from curtain drains, septic tanks, and residential water wells. Nitrate concentrations in the curtain drains ranged from 0.03 to 3.53 mg/L (milligrams per liter), as N. Concentrations of chloride in 10 of the 11 curtain drains ranged from 5.5 to 21 mg/L; the chloride concentration in the eleventh curtain drain was 340 mg/L. Bromide concentrations in 11 curtain drains ranged from 0.01 to 0.22 mg/L. Cl/Br ratios ranged from 86 to 2,000. F-specific coliphage were not found in any curtain-drain samples. Concentrations of E. coli in the curtain drains ranged from 1 to 760 colonies per 100 milliliters. The curtain-drain water-quality data were evaluated to determine whether HSTS-derived water was present in the curtain drains. Nutrient concentrations were too low to be of use in the determination. The Cl/Br ratios appear promising. Coliphage was not detected in the curtain drains, so genotyping could not be attempted. E. coli concentrations in the curtain drains were all less than those from the corresponding HSTS; only one sample exceeded the Ohio secondary-contact water-quality standard. The genetic fingerprinting data were inconclusive because multiple links between unrelated sites were found. Although the curtain-drain samples from the ETA systems showed somewhat more evidence of the presence of HSTS water than did the LL systems, most of the approaches were inconclusive by themselves. The best evidence of HSTS water, from the Cl/Br ratios, indicates that the water in 10 of the 11 curtain drains, at both HSTS types, was a mixture of dilute ground water and HSTS-derived water; the 11th drain also show some effects of the HSTS, although road salt-affected water may be present. Therefore, it appears that there is no difference between the ETA and LL systems with respect to the water quality in curtain drains.

Safety drain system for fluid reservoir

NASA Technical Reports Server (NTRS)

England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)

2012-01-01

A safety drain system includes a plurality of drain sections, each of which defines distinct fluid flow paths. At least a portion of the fluid flow paths commence at a side of the drain section that is in fluid communication with a reservoir's fluid. Each fluid flow path at the side communicating with the reservoir's fluid defines an opening having a smallest dimension not to exceed approximately one centimeter. The drain sections are distributed over at least one surface of the reservoir. A manifold is coupled to the drain sections.

Mercury at the Oat Hill Extension Mine and James Creek, Napa County, California: Tailings, Sediment, Water, and Biota, 2003-2004

USGS Publications Warehouse

Slowey, Aaron J.; Rytuba, James J.; Hothem, Roger L.; May, Jason T.

2007-01-01

Executive Summary The Oat Hill Extension (OHE) Mine is one of several mercury mines located in the James Creek/Pope Creek watershed that produced mercury from the 1870's until 1944 (U.S. Bureau of Mines, 1965). The OHE Mine developed veins and mineralized fault zones hosted in sandstone that extended eastward from the Oat Hill Mine. Waste material from the Oat Hill Mine was reprocessed at the OHE Mine using gravity separation methods to obtain cinnabar concentrates that were processed in a retort. The U.S. Bureau of Land Management requested that the U.S. Geological Survey measure and characterize mercury and other chemical constituents that are potentially relevant to ecological impairment of biota in tailings, sediment, and water at the OHE Mine and in the tributaries of James Creek that drain the mine area (termed Drainage A and B) (Figs. 1 and 2). This report summarizes such data obtained from sampling of tailings and sediments at the OHE on October 17, 2003; water, sediment, and biota from James Creek on May 20, 2004; and biota on October 29, 2004. These data are interpreted to provide a preliminary assessment of the potential ecological impact of the mine on the James Creek watershed. The mine tailings are unusual in that they have not been roasted and contain relatively high concentrations of mercury (400 to 1200 ppm) compared to unroasted waste rock at other mines. These tailings have contaminated a tributary to James Creek with mercury primarily by erosion, on the basis of higher concentration of mercury (780 ng/L) measured in unfiltered (total mercury, HgT) spring water flowing from the OHE to James Creek compared to 5 to 14 ng/L HgT measured in James Creek itself. Tailing piles (presumably from past Oat Hill mine dumping) near the USBLM property boundary and upstream of the main OHE mine drainage channel (Drainage A; Fig. 2) also likely emit mercury, on the basis of their mercury composition (930 to 1200 ppm). The OHE spring water is likely an appreciable source of sulfate and carbonate to James Creek, because the spring water was enriched in sulfate (130 mg/L) and carbonate (430 mg/L as CaCO3) compared to James Creek water (70 to 100 mg/L SO42- and 110 to 170 mg/L as CaCO3) at the time of sampling. Concentrations of mercury in active channel sediment from James Creek are variable and potentially high, on the basis of chemical analysis (2.5 to 17 _g/g-wet sediment) and easily visible cinnabar grains in panned concentrates. Average (geometric mean) organic mercury (presumably monomethyl mercury (MMHg); ?2.3.3) concentrations in several invertebrate taxa collected from the James Creek watershed locations were higher than invertebrates taken from a Northern California location lacking a known point source of mercury. The mean proportion of MMHg to total mercury in James Creek predatory insect samples was 40 percent (1 standard deviation = 30 percent); only 40 percent of all insect samples had a MMHg/HgT proportion greater than 0.5. The low proportions of MMHg measured in invertebrates in James Creek and the presence of cinnabar in the creek suggest that some invertebrates may have anomolously high Hg concentrations as a result of the injestion or adhesion of extremely fine-grained cinnabar particles. Interpretation of HgT in frogs and fish as an indicator of mercury reactivity, biouptake, or trophic transfer is limited, pending MMHg measuremens, by the possibility of these whole-body samples having contained cinnabar particles at the time of analysis. To minimize this limitation, the gastrointestinal tracts and external surfaces of all amphibians, where cinnabar most likely resides, were carefully flushed to remove any visible particles. However, extremely fine-grained, invisible, adhesive cinnabar particles likely exist in the amphibians' habitats. HgT in foothill yellow-legged frogs collected from the James Creek study area, ranging from 0.1 to 0.6 ug/g Hg, was on average twice that of an extensive

Containment vessel drain system

DOEpatents

Harris, Scott G.

2018-01-30

A system for draining a containment vessel may include a drain inlet located in a lower portion of the containment vessel. The containment vessel may be at least partially filled with a liquid, and the drain inlet may be located below a surface of the liquid. The system may further comprise an inlet located in an upper portion of the containment vessel. The inlet may be configured to insert pressurized gas into the containment vessel to form a pressurized region above the surface of the liquid, and the pressurized region may operate to apply a surface pressure that forces the liquid into the drain inlet. Additionally, a fluid separation device may be operatively connected to the drain inlet. The fluid separation device may be configured to separate the liquid from the pressurized gas that enters the drain inlet after the surface of the liquid falls below the drain inlet.

Evaluation of wick drain performance in Virginia soils.

DOT National Transportation Integrated Search

2003-01-01

Prefabricated vertical drains (PVD), also known as wick drains, are commonly used to accelerate the consolidation of fine-grained soils in order to reduce future settlements and increase shear strength. Various drain designs are currently on the mark...

Effect of abdominopelvic abscess drain size on drainage time and probability of occlusion.

PubMed

Rotman, Jessica A; Getrajdman, George I; Maybody, Majid; Erinjeri, Joseph P; Yarmohammadi, Hooman; Sofocleous, Constantinos T; Solomon, Stephen B; Boas, F Edward

2017-04-01

The purpose of this study is to determine whether larger abdominopelvic abscess drains reduce the time required for abscess resolution or the probability of tube occlusion. 144 consecutive patients who underwent abscess drainage at a single institution were reviewed retrospectively. Larger initial drain size did not reduce drainage time, drain occlusion, or drain exchanges (P > .05). Subgroup analysis did not find any type of collection that benefitted from larger drains. A multivariate model predicting drainage time showed that large collections (>200 mL) required 16 days longer drainage time than small collections (<50 mL). Collections with a fistula to bowel required 17 days longer drainage time than collections without a fistula. Initial drain size and the viscosity of the fluid in the collection had no significant effect on drainage time in the multivariate model. 8 F drains are adequate for initial drainage of most serous and serosanguineous collections. 10 F drains are adequate for initial drainage of most purulent or bloody collections. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors affecting the transformation of a pyritic tailing: scaled-up column tests.

PubMed

García, C; Ballester, A; González, F; Blázquez, M L

2005-02-14

Two different methods for predicting the quality of the water draining from a pyritic tailing are compared; for this, a static test (ABA test) and a kinetic test in large columns were chosen. The different results obtained in the two experimental set-ups show the necessity of being careful in selecting both the adequate predictive method and the conclusions and extrapolations derived from them. The tailing chosen for the weathering tests (previously tested in shake flasks and in small weathering columns) was a pyritic residue produced in a flotation plant of complex polymetallic sulphides (Huelva, Spain). The ABA test was a modification of the conventional ABA test reported in bibliography. The modification consisted in the soft conditions employed in the digestion phase. For column tests, two identical methacrylate columns (150 cm high and 15 cm diameter) were used to study the chemical and microbiological processes controlling the leaching of pyrite. The results obtained in the two tests were very different. The static test predicted a strong potential acidity for the tailing. On the contrary, pH value in the effluents draining from the columns reached values of only 5 units, being the concentration of metals (<600 mg/L) and sulphate ions (<17,000 mg/L) very small and far from the values of a typical acid mine drainage. In consequence, the static test may oversize the potential acidity of the tailing; whereas large columns may be saturated in water, displacing the oxygen and inhibiting the microbial activity necessary to catalyse mineral oxidation.

Preferential flow estimates to an agricultural tile drain with implications for glyphosate transport

USGS Publications Warehouse

Stone, W.W.; Wilson, J.T.

2006-01-01

Agricultural subsurface drains, commonly referred to as tile drains, are potentially significant pathways for the movement of fertilizers and pesticides to streams and ditches in much of the Midwest. Preferential flow in the unsaturated zone provides a route for water and solutes to bypass the soil matrix and reach tile drains faster than predicted by traditional displacement theory. This paper uses chloride concentrations to estimate preferential flow contributions to a tile drain during two storms in May 2004. Chloride, a conservative anion, was selected as the tracer because of differences in chloride concentrations between the two sources of water to the tile drain, preferential and matrix flow. A strong correlation between specific conductance and chloride concentration provided a mechanism to estimate chloride concentrations in the tile drain throughout the storm hydrographs. A simple mixing analysis was used to identify the preferential flow component of the storm hydrograph. During two storms, preferential flow contributed 11 and 51% of total storm tile drain flow; the peak contributions, 40 and 81%, coincided with the peak tile drain flow. Positive relations between glyphosate [N-(phosphonomethyl)glycine] concentrations and preferential flow for the two storms suggest that preferential flow is an important transport pathway to the tile drain. ?? ASA, CSSA, SSSA.

Aquatic assessment of the Pike Hill Copper Mine Superfund site, Corinth, Vermont

USGS Publications Warehouse

Piatak, Nadine M.; Argue, Denise M.; Seal, Robert R.; Kiah, Richard G.; Besser, John M.; Coles, James F.; Hammarstrom, Jane M.; Levitan, Denise M.; Deacon, Jeffrey R.; Ingersoll, Christopher G.

2013-01-01

The Pike Hill Copper Mine Superfund site in Corinth, Orange County, Vermont, includes the Eureka, Union, and Smith mines along with areas of downstream aquatic ecosystem impairment. The site was placed on the U.S. Environmental Protection Agency (USEPA) National Priorities List in 2004. The mines, which operated from about 1847 to 1919, contain underground workings, foundations from historical structures, several waste-rock piles, and some flotation tailings. The mine site is drained to the northeast by Pike Hill Brook, which includes several wetland areas, and to the southeast by an unnamed tributary that flows to the south and enters Cookville Brook. Both brooks eventually drain into the Waits River, which flows into the Connecticut River. The aquatic ecosystem at the site was assessed using a variety of approaches that investigated surface-water quality, sediment quality, and various ecological indicators of stream-ecosystem health. The degradation of surface-water quality is caused by elevated concentrations of copper, and to a lesser extent cadmium, with localized effects caused by aluminum, iron, and zinc. Copper concentrations in surface waters reached or exceeded the USEPA national recommended chronic water-quality criteria for the protection of aquatic life in all of the Pike Hill Brook sampling locations except for the location farthest downstream, in half of the locations sampled in the tributary to Cookville Brook, and in about half of the locations in one wetland area located in Pike Hill Brook. Most of these same locations also contained concentrations of cadmium that exceeded the chronic water-quality criteria. In contrast, surface waters at background sampling locations were below these criteria for copper and cadmium. Comparison of hardness-based and Biotic Ligand Model (BLM)-based criteria for copper yields similar results with respect to the extent or number of stations impaired for surface waters in the affected area. However, the BLM-based criteria are commonly lower values than the hardness-based criteria and thus suggest a greater degree or magnitude of impairment at the sampling locations. The riffle-habitat benthic invertebrate richness and abundance data correlate strongly with the extent of impact based on water quality for both brooks. Similarly, the fish community assessments document degraded conditions throughout most of Pike Hill Brook, whereas the data for the tributary to Cookville Brook suggest less degradation to this brook. The sediment environment shows similar extents of impairment to the surface-water environment, with most sampling locations in Pike Hill Brook, including the wetland areas, and the tributary to Cookville Brook affected. Sediment impairment is caused by elevated copper concentrations, although localized degradation due to elevated cadmium and zinc concentrations was documented on the basis of exceedances of probable effects concentrations (PECs). In contrast to impairment determined by exceedances of PECs, equilibrium-partitioning sediment benchmarks (based on simultaneously extracted metals, acid volatile sulfides, and total organic carbon) predict no toxic effects in sediments at the background locations and uncertain toxic effects throughout Pike Hill Brook and the tributary to Cookville Brook, with the exception of the most downstream Cookville Brook location, which indicated no toxic effects. Acute laboratory toxicity testing using the amphipod Hyalella azteca and the midge Chironomus dilutus on pore waters extracted from sediment in situ indicate impairment (based on tests with H. azteca) at only one location in Pike Hill Brook and no impairment in the tributary to Cookville Brook. Chronic laboratory sediment toxicity testing using H. azteca and C. dilutus indicated toxicity in Pike Hill Brook at several locations in the lower reach and two locations in the tributary to Cookville Brook. Toxicity was not indicated for either species in sediment from the most acidic metal-rich location, likely due to the low lability of copper in that sediment, as indicated by a low proportion of extractable copper (simultaneously extracted metal (SEM) copper only 5 percent of total copper) and due to the flushing of acidic metal-rich pore water from experimental chambers as overlying test water was introduced before and replaced periodically during the toxicity tests. Depositional habitat invertebrate richness and abundance data generally agreed with the results of toxicity tests and with the extent of impact in the watersheds on the basis of sediment and pore waters. The information was used to develop an overall assessment of the impact of mine drainage on the aquatic system downstream from the Pike Hill copper mines. Most of Pike Hill Brook, including several wetland areas that are all downstream from the Eureka and Union mines, was found to be impaired on the basis of water-quality data and biological assessments of fish or benthic invertebrate communities. In contrast, only one location in the tributary to Cookville Brook, downstream from the Smith mine, is definitively impaired. The biological community begins to recover at the most downstream locations in both brooks due to natural attenuation from mixing with unimpaired streams. On the basis of water quality and biological assessment, the reference locations were of good quality. The sediment toxicity, chemistry, and aquatic community survey data suggest that the sediments could be a source of toxicity in Pike Hill Brook and the tributary to Cookville Brook. On the basis of water quality, sediment quality, and biologic communities, the impacts of mine drainage on the aquatic ecosystem health of the watersheds in the study area are generally consistent with the toxicity suggested from laboratory toxicity testing on pore water and sediments.

Phytoplankton abundance and structure as indicator of water quality in the drainage system of the Burullus Lagoon, southern Mediterranean coast, Egypt.

PubMed

El-Kassas, Hala Yassin; Gharib, Samiha Mahmoud

2016-09-01

This study represents the first detailed account of phytoplankton community structure and seasonal succession in eight drain sites and the Brimbal Canal influx into the Burullus Lagoon. The phytoplankton characteristics were studied based on the data collected seasonally over 4 years, from summer 2012 to spring 2016. Various indices such as Palmer's and Shannon's biotic indices were used for the assessment of the water quality of the different drains. There were a total of 194 species belonging to 65 genera and 6 groups: Bacillariophyceae (76 species), Chlorophyceae (59 species), Cyanophyceae (30 species), Euglenophyceae (25 species), Dinophyceae (3 species), and Xanthophyceae (1 species). The phytoplankton community was dominated with diatoms, green algae, and euglenoids such as Cyclotella, Scenedesmus, Navicula, Nitzschia, Ankistrodesmus, Chlorella, and Euglena. Maximum and minimum phytoplankton abundance was recorded at the Brimbal Canal and Hooks Drain. Maximum and minimum species diversities (H') were found at the Hooks Drain (2.564) and Burullus Drain (2.055). Species evenness fluctuated between 0.595 (Burullus Drain) and 0.750 (West Burullus Drain). The total score of algal genus pollution index and the algal species pollution index at the different drains showed that Drain 7 and the West Burullus Drain had moderate pollution, and the total score of the other drains were greater than 20 indicating the confirmed high organic pollution. Thus, the present investigation can be considered an attempt to use the phytoplankton community as a bioindicator of organic pollution.

Mercury Geochemistry of Gold Placer Tailings, Sediments, Bedrock, and Waters in the Lower Clear Creek Area, Shasta County, California - Report of Investigations, 2001-2003

USGS Publications Warehouse

Ashley, Roger P.; Rytuba, James J.

2008-01-01

Clear Creek, one of the major tributaries of the upper Sacramento River, drains the eastern Trinity Mountains. Alluvial plain and terrace gravels of lower Clear Creek, at the northwest edge of the Sacramento Valley, contain placer gold that has been mined since the Gold Rush by various methods including hydraulic mining and dredging. In addition, from the 1950s to the 1980s aggregate-mining operations removed gravel from the lower Clear Creek flood plain. Since Clear Creek is an important stream for salmon production, a habitat restoration program is underway to repair damage from mining and improve conditions for spawning. This program includes moving dredge tailings to increase the area of spawning gravel and to fill gravel pits in the flood plain, raising the concern that mercury lost to these tailings in the gold recovery process may be released and become available to biota. The purposes of our study are to identify sources, transport, and dispersal of mercury in the lower Clear Creek area and identify environments in which bioavailable methylmercury is produced. Analytical data acquired include total mercury and methylmercury concentrations in sediments, tailings, and water. Mercury concentrations in bedrock and unmined gravels in and around the mined area are low and are taken to represent background concentrations. Bulk mercury values in placer mining tailings range from near-background in coarse dry materials to more than 40 times background in sands and silts exposed to mercury in sluices. Tailings are entrained in flood-plain sediments and active stream sediments; consequently, mercury concentrations in these materials range from background to about two to three times background. Mercury in sediments and tailings is associated with fine size fractions. The source of most of this mercury is historical gold mining in the Clear Creek watershed. Although methylmercury levels are low in most of these tailings and sediments, flood-plain sediment in shallow flood-plain ponds, tailings in a dredge pond, and active stream sediment in a Clear Creek backwater have elevated levels of methylmercury. Stream waters in the area show low mercury levels during both summer and winter base-flow conditions. During winter high flows total mercury increases by about one order of magnitude; this additional mercury is associated with suspended particulate material. Methylmercury is low in stream waters. Ponds in various environments generally have higher total mercury levels in waters than Clear Creek under base-flow conditions and higher methylmercury levels in both sediments and waters. Ponds are probably the main source of bioavailable mercury in the lower Clear Creek area. Several saline springs occur in the area. The saline waters are enriched in lithium, boron, and mercury, similar to connate waters that are expelled along thrust faults to the south on the west side of the Sacramento Valley. Saline springs may locally contribute some mercury to pond and drainage waters.

Discharge characteristics of four highway drainage systems in Ohio

USGS Publications Warehouse

Straub, D.E.

1995-01-01

Excessive water in the subbase of high-way combined with large traffic volumes and heavy loads is a major cause of road deterioration. Prompt removal of any excess water in a subbase will decrease the road deterioration and extend the effective life of a highway. This study presents discharge characteristics of four highway subbase drainage systems. These systems consisted of shallow, longitudal trenches with geocomposite drain materials (edge drains made from a polyethylene core surrounded by a geotextile filter fabric) that underline the joint between the shoulder and the traffic lane of State Route 16, approximately 1.0 mile southeast of Granville, Ohio. For selected rainfall-runoff events the maximum discharge, discharge characteristics from April 1991 through November 1993 were computed for three geocomposite products- a post type, an oblong-pipe type, and a cusp type-and a conventional perforated pipe edge drain. In general, the discharge characteristics of the conventional edge drain and that of the oblong-pipe edge drain were similar for most of the rainfall-runoff event characteristics. Both produced most of the highest maximum discharges and largest discharge volumes among the four longitudal edge drains. The post edge drain produced smaller maximum discharge and volumes than the conventional and oblong-pipe edge drains, but it had the shortest lag times for most of the event characteristics. The cusp edge drain produced small maximum discharges and small volumes similar to those from the post edge drain, but it had the longest lag times of all the edge drains for most of the event characteristics. The cusp edge drain may have also had some problems during installation which could have affected the discharge characteristics.

Fallopian Tube Herniation through Left Sided Abdominal Drain Site.

PubMed

Hussain, Khalid; Masood, Jovaria

2016-06-01

Intra-abdominal drains have been used since long to prevent intra-abdominal collection, and detect any anastomotic leaks. We report a case of left sided fallopian tube herniation from a left lower abdominal drain site in a 27-year female who underwent caesarian section for breach presentation. Several complications related to drain usage has been described but left sided fallopian tube prolapse through drain site has not been reported in literature.

Drain Management after Pancreatoduodenectomy: Reappraisal of a Prospective Randomized Trial Using Risk Stratification.

PubMed

McMillan, Matthew T; Malleo, Giuseppe; Bassi, Claudio; Butturini, Giovanni; Salvia, Roberto; Roses, Robert E; Lee, Major K; Fraker, Douglas L; Drebin, Jeffrey A; Vollmer, Charles M

2015-10-01

A recent randomized trial used the Fistula Risk Score (FRS) to develop guidelines for selective drainage based on clinically relevant fistula (CR-POPF) risk. Additionally, postoperative day (POD) 1 drain and serum amylase have been identified as accurate postoperative predictors of CR-POPF. This study sought to identify patients who may benefit from selective drainage, as well as the optimal timing for drain removal after pancreatoduodenectomy. One hundred six pancreatoduodenectomies from a previously reported RCT were assessed using risk-adjustment. The incidence of CR-POPF was compared between FRS risk cohorts. Drain and serum amylase values from POD 1 were evaluated using receiver operating characteristic (ROC) analysis to establish cut-offs predictive of CR-POPF occurrence. A regression analysis compared drain removal randomizations (POD 3 vs POD 5). Three-quarters of patients had moderate/high CR-POPF risk. This group had a CR-POPF rate of 36.3% vs 7.7% among negligible/low risk patients (p = 0.005). The areas under the ROC curve for CR-POPF prediction using POD 1 drain and serum amylase values were 0.800 (p = 0.000001; 95% CI 0.70-0.90) and 0.655 (p = 0.012; 95% CI 0.55-0.77), respectively. No significant serum amylase cut-offs were identified. Moderate/high risk patients with POD 1 drain amylase ≤ 5,000 U/L had significantly lower rates of CR-POPF when randomized to POD 3 drain removal (4.2% vs 38.5%; p = 0.003); moreover, these patients experienced fewer complications and shorter hospital stays. A clinical care protocol is proposed whereby drains are recommended for moderate/high FRS risk patients, but may be omitted in patients with negligible/low risk. Drain amylase values in moderate/high risk patients should then be evaluated on POD 1 to determine the optimal timing for drain removal. Moderate/high risk patients with POD 1 drain amylase ≤ 5,000 U/L have lower rates of CR-POPF with POD 3 (vs POD ≥ 5) drain removal; early drain removal is recommended for these patients. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Effect of polluted water on soil and plant contamination by heavy metals in El-Mahla El-Kobra, Egypt

NASA Astrophysics Data System (ADS)

Kasem Mahmoud, Esawy; Ghoneim, Adel Mohamed

2016-04-01

The discharge of untreated waste water in Zefta drain and drain no. 5 is becoming a problem for many farmers in the El-Mahla El-Kobra area, Egypt. The discharged water contains high levels of contaminants considered hazardous to the ecosystem. Some plants, soil, water, and sediment samples were collected from the El-Mahla El-Kobra area to evaluate the contamination by heavy metals. The results showed that the heavy metals, pH, sodium adsorption ratio (SAR), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) in the water of Zefta drain and drain no. 5 exceeded permissible limits for irrigation. In rice and maize shoots grown in soils irrigated by contaminated water from Zefta drain and drain no. 5, the bioaccumulation factors for Cd, Pb, Zn, Cu, and Mn were higher than 1.0. The heavy metals content of irrigated soils from Zefta drain and drain no. 5 exceeded the upper limit of background heavy metals. In this study, the mean contaminant factor values of the drain no. 5 sediments revealed that Zn, Mn, Cu, Cd, Pb, and Ni > 6, indicating very high contamination. The bioaccumulation coefficient values of Cynodon dactylon, Phragmites australis, and Typha domingensis aquatic plants growing in Zefta drain are high. These species can be considered as hyperaccumulators for the decontamination of contaminated water.

A novel thin-film transistor with step gate-overlapped lightly doped drain and raised source/drain design

NASA Astrophysics Data System (ADS)

Chien, Feng-Tso; Chen, Jian-Liang; Chen, Chien-Ming; Chen, Chii-Wen; Cheng, Ching-Hwa; Chiu, Hsien-Chin

2017-11-01

In this paper, a novel step gate-overlapped lightly doped drain (GOLDD) with raised source/drain (RSD) structure (SGORSD) is proposed for TFT electronic device application. The new SGORSD structure could obtain a low electric field at channel near the drain side owing to a step GOLDD design. Compared to the conventional device, the SGORSD TFT exhibits a better kink effect and higher breakdown performance due to the reduced drain electric field (D-EF). In addition, the leakage current also can be suppressed. Moreover, the device stability, such as the threshold voltage shift and drain current degradation under a high gate bias, is improved by the design of SGORSD structure. Therefore, this novel step GOLDD structure can be a promising design to be used in active-matrix flat panel electronics.

Landscape geochemistry near mineralized areas of eastern Alaska: Chapter H in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

USGS Publications Warehouse

Wang, Bronwen; Gough, Larry P.; Wanty, Richard B.; Crock, James G.; Lee, Gregory K.; Day, Warren C.; Vohden, Jim

2007-01-01

The Pogo lode gold deposit was discovered in eastern Alaska in the early 1990s and provided the opportunity to study elemental distribution and mobility in the natural environment prior to mine development. Studying mineralized systems prior to mining allows us to compare the natural biogeochemical signature in mineralized versus nonmineralized areas. The resultant data and interpretation also provide a baseline for evaluating what, if any, changes in elemental distribution result from development. This report investigates the chemistry of stream water, streambed sediment, and soil in the context of regional bedrock geology. The major-ion chemistry of the waters reflects a rock-dominated aqueous system, and the waters are classified as Ca2+ and Mg2+ - HCO3- to Ca2+ and Mg2+ - SO4-2 waters. Creeks draining the gneissic lithologies tend to be more sulfate dominated than those draining the intrusive units. Sulfate also dominated creeks draining mineralized areas; however, the underlying paragneiss unit could be contributing substantially to the sulfate concentration, and the sulfate concentration in these creeks may reflect a complex baltholith-paragneiss boundary rather than mineralization. Arsenic concentrations in bed sediments were elevated in mineralized areas relative to nonmineralized areas. Elevated concentrations of nickel, chromium, iron, manganese, and cobalt appear to reflect the presence of ultramafic rocks in the drainage. In general, aqueous metal concentrations were below the State of Alaska’s Aquatic Life Criteria and Drinking Water Standards, with the exception of arsenic in stream water, which ranged in concentration from less than 1 to 14 micrograms per liter (μg/L) and exceeded the drinking water standard at one site. The arsenic and antimony concentration in the A, B, and C soil horizons ranged from 3 to 410 milligrams per kilogram (mg/kg), 6.1 to 440 mg/kg, and 2 to 300 mg/kg, respectively, for arsenic and 0.4 to 24 mg/kg, 0.6 to 25 mg/kg, and 0.2 to 16 mg/kg, respectively, for antimony. The arsenic and antimony concentrations in stream waters correlate well with the concentrations in soils. However, significantly less arsenic and antimony was extracted from C horizon soils in water leaching experiments, indicating that the arsenic and antimony in the C horizon is present in a less available form than in the A or B horizons. Arsenic and antimony uptake by grayleaf willow (Salix glauca L.) appears minimal, with arsenic concentrations ranging from less than 0.01 to 0.14 mg/kg and antimony concentrations ranging from less than 0.003 to 0.23 mg/kg in willow leaves. In general, the highest concentrations of both arsenic and antimony in water and soils were found near mineralized areas. Elevated arsenic concentrations were also found in bed sediments from mineralized areas. In these sample matrices, the presence of arsenic and (or) antimony was a good indicator of contact with mineralized rock units.

Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery.

PubMed

Connolly, J; Holden, N M

2017-12-01

Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA) was performed on a very high resolution satellite image (Geoeye-1) to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality (CCQ) were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA) of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95-97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO 2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of drains on a blanket bog in the west of Ireland. The results show that information on drain extent and location can be extracted from high resolution imagery and mapped with a high degree of accuracy. Under Article 3.4 of the Kyoto Protocol Annex 1 parties can account for greenhouse gas emission by sources and removals by sinks resulting from "wetlands drainage and rewetting". The ability to map the spatial extent, density and location of peatlands drains means that Annex 1 parties can develop strategies for drain blocking to aid reduction of CO 2 emissions, DOC runoff and water discoloration. This paper highlights some uncertainty around using one-size-fits-all emission factors for GHG in drained peatlands and re-wetting scenarios. However, the OBIA method is robust and accurate and could be used to assess the extent of drains in peatlands across the globe aiding the refinement of peatland carbon dynamics .

Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery.

PubMed

Connolly, J; Holden, N M

2017-12-01

Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA) was performed on a very high resolution satellite image (Geoeye-1) to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality ( CCQ ) were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA) of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95-97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO 2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of drains on a blanket bog in the west of Ireland. The results show that information on drain extent and location can be extracted from high resolution imagery and mapped with a high degree of accuracy. Under Article 3.4 of the Kyoto Protocol Annex 1 parties can account for greenhouse gas emission by sources and removals by sinks resulting from "wetlands drainage and rewetting". The ability to map the spatial extent, density and location of peatlands drains means that Annex 1 parties can develop strategies for drain blocking to aid reduction of CO 2 emissions, DOC runoff and water discoloration. This paper highlights some uncertainty around using one-size-fits-all emission factors for GHG in drained peatlands and re-wetting scenarios. However, the OBIA method is robust and accurate and could be used to assess the extent of drains in peatlands across the globe aiding the refinement of peatland carbon dynamics .

Comparative effect of tube drain on post operative inflammatory complications of impacted mandibular third molar surgery College Hospital, Ibadan, Nigeria.

PubMed

Obimakinde, O S; Fasola, A O; Arotiba, J T; Okoje, V N; Obiechina, A E

2010-09-01

Swelling, pain and trismus are acute reversible inflammatory complications of impacted mandibular third molar (M3) surgery. They contribute to the deterioration of quality of life and loss of several useful working hours. This study aimed to investigate whether the use of a surgical drain following M3 surgery can minimise these inflammatory complications. Eighty consecutive patients who gave consent were enrolled into the study. Patients were assigned into two groups (drain and no drain) by systematic sampling method which was modified to ensure matching of patients by age, sex and spatial relationship of the impacted mandibular third molar. The patients in the drain group (n=40) had a Foley's catheter drain inserted into the wound after the surgical procedure while the patients in the no drain group (n=40) had their wound closed without the use of drain. All patients had primary wound closure with 3.0 black silk sutures after the procedure. Demographic data, cheek dimension and maximal mouth opening were recorded before the procedure. Pain, swelling and trismus were evaluated in the two groups at 24 hours, 48 hours and 7th day after surgery. Post operative swelling and visual analogue scale score for pain were comparatively lesser in the drain group patients. The maximal interincisal distance was also more in the drain group patients. The findings from this study indicated that there is a significant benefit of using a surgical drain in minimising postoperative oedema, pain and trismus following surgical removal of impacted mandibular third molar.

77 FR 70382 - Airworthiness Directives; Eurocopter France Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

... the fuel tank draining system. This proposed AD is prompted by a closed fuel tank drain that, in the... fuel tank compartments' draining system. FAA's Determination These helicopters have been approved by... buoyancy fixed parts, the ASBs describe procedures to modify the fuel tank draining system by removing...

14 CFR 29.1021 - Oil system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil system drains. 29.1021 Section 29.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 25.1021 - Oil system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil system drains. 25.1021 Section 25.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 29.1021 - Oil system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil system drains. 29.1021 Section 29.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 25.1021 - Oil system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil system drains. 25.1021 Section 25.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 125.139 - Oil system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Oil system drains. 125.139 Section 125.139....139 Oil system drains. Accessible drains incorporating either a manual or automatic means for positive locking in the closed position must be provided to allow safe drainage of the entire oil system. ...

14 CFR 125.139 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Oil system drains. 125.139 Section 125.139....139 Oil system drains. Accessible drains incorporating either a manual or automatic means for positive locking in the closed position must be provided to allow safe drainage of the entire oil system. ...

14 CFR 125.139 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Oil system drains. 125.139 Section 125.139....139 Oil system drains. Accessible drains incorporating either a manual or automatic means for positive locking in the closed position must be provided to allow safe drainage of the entire oil system. ...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

Hydrology and subsidence potential of proposed coal-lease tracts in Delta County, Colorado

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

Brooks, T.

Potential subsidence from underground coal mining and associated hydrologic impacts were investigated at two potential coal-lease tracts in Delta County, Colorado. Alteration of existing flow systems could affect water users in the surrounding area. An inventory was made of 20 wells (18 in the Paonia study area and 2 in the Cedaredge study area) and 16 springs in the Paonia study area. Wells completed in the Mesaverde Formation yielded a sodium bicarbonate type water. Water levels in wells ranged from 149 to 2209 feet below the land surface in the Paonia study area and were 25 and 217 feet belowmore » the land surface in the Cedaredge study area. Spring discharges in the Paonia study area ranged from 0.02 to 8.41 gallons per minute. The waters were of the calcium sodium bicarbonate type. Tests conducted in October 1982 indicated that Terror Creek in the Paonia study area lost 0.59 cubic foot per second along about 1.5 miles of thin alluvium overlying the lower Mesaverde Formation. Measurements in the same week indicated that Oak Creek in the Cedaredge study area gained 0.92 cubic foot per second along about 1.5 miles of thick alluvium overlying the Mesaverde Formation. The stream waters were a calcium bicarbonate type. Mining beneath Stevens Gulch and East Roatcap Creek could produce surface expressions of subsidence. Subsidence could partly drain alluvial valley aquifers or streamflow in these drainages. 21 refs.« less

Pontine infarction caused by medial branch injury of the basilar artery as a rare complication of cisternal drain placement.

PubMed

Horiuchi, Tetsuyoshi; Yamamoto, Yasunaga; Kuroiwa, Masafumi; Rahmah, Nunung Nur; Hongo, Kazuhiro

2012-04-01

We present a rare complication of cisternal drain placement during aneurysm surgery. A ruptured anterior communicating artery aneurysm was clipped through a right pterional approach. A cisternal drain was inserted from the retro-carotid to the prepontine cistern. Postoperatively, a left-sided paresis of the upper extremity had developed. A CT brain scan revealed that the drain was located between the pons and the basilar artery, resulting in a pontine infarction. Vascular neurosurgeons should keep this complication in mind when placing a cisternal drain tube. The drain tube should not be inserted too deep into the prepontine cistern. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

Han, Dong-Suk; Kang, Yu-Jin; Park, Jae-Hyung

Highlights: • We developed and investigated source/drain electrodes in oxide TFTs. • The Mo S/D electrodes showed good output characteristics. • Intrinsic TFT parameters were calculated by the transmission line method. - Abstract: This paper investigates the feasibility of a low-resistivity electrode material (Mo) for source/drain (S/D) electrodes in thin film transistors (TFTs). The effective resistances between Mo source/drain electrodes and amorphous zinc–tin-oxide (a-ZTO) thin film transistors were studied. Intrinsic TFT parameters were calculated by the transmission line method (TLM) using a series of TFTs with different channel lengths measured at a low source/drain voltage. The TFTs fabricated with Momore » source/drain electrodes showed good transfer characteristics with a field-effect mobility of 10.23 cm{sup 2}/V s. In spite of slight current crowding effects, the Mo source/drain electrodes showed good output characteristics with a steep rise in the low drain-to-source voltage (V{sub DS}) region.« less

Rupture disc

DOEpatents

Newton, Robert G.

1977-01-01

The intermediate heat transport system for a sodium-cooled fast breeder reactor includes a device for rapidly draining the sodium therefrom should a sodium-water reaction occur within the system. This device includes a rupturable member in a drain line in the system and means for cutting a large opening therein and for positively removing the sheared-out portion from the opening cut in the rupturable member. According to the preferred embodiment of the invention the rupturable member includes a solid head seated in the end of the drain line having a rim extending peripherally therearound, the rim being clamped against the end of the drain line by a clamp ring having an interior shearing edge, the bottom of the rupturable member being convex and extending into the drain line. Means are provided to draw the rupturable member away from the drain line against the shearing edge to clear the drain line for outflow of sodium therethrough.

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

Nutrient Drain Associated with Hardwood Plantation Culture

Treesearch

James B. Baker

1978-01-01

Past research and a tentative evaluation indicate that nutrient drain and possible site degradation could occur in southern hardwood plantations. The extent of nutrient drain on a given site would depend on the species, length of the rotation, and harvesting system used. The evaluation for cottonwood plantations in Mississippi indicates that nutrient drain is most...

The management of vacuum neck drains in head and neck surgery and the comparison of two different practice protocols for drain removal.

PubMed

Kasbekar, A V; Davies, F; Upile, N; Ho, M W; Roland, N J

2016-01-01

Introduction The management of vacuum neck drains in head and neck surgery is varied. We aimed to improve early drain removal and therefore patient discharge in a safe and effective manner. Methods The postoperative management of head and neck surgical patients with vacuum neck drains was reviewed retrospectively. A new policy was then implemented to measure drainage three times daily (midnight, 6am, midday). The decision for drain removal was based on the most recent drainage period (at <3ml per hour). A further patient cohort was subsequently assessed prospectively. The length of hospital stay was compared between the cohorts. Results The retrospective audit included 51 patients while the prospective audit included 47. The latter saw 16 patients (33%) discharged at least one day earlier than they would have been under the previous policy. No adverse effects were noted from earlier drain removal. Conclusions Measuring drainage volumes three times daily allows for more accurate assessment of wound drainage, and this can lead to earlier removal of neck drains and safe discharge.

The health workforce crisis: the brain drain scourge.

PubMed

Ike, Samuel O

2007-01-01

The magnitude of the health workforce crisis engendered by brain drain particularly in Africa, and nay more especially Nigeria, has been assuming increasingly alarming proportions in the past three decades. The challenge it poses in meeting the manpower needs in the healthcare sector as well as in the larger economy of the sending countries is enormous. This paper thus sets out to highlight the scope of this brain drain, its effects and the reasons sustaining it, as well as makes concrete suggestions to help stern the tide. A review of the literature on brain drain with particular emphasis on the health workforce sector was done, with focus on Africa, and specifically Nigeria. Literature search was done using mainly the Medline, as well as local journals. The historical perspectives, with the scope of external and internal brain drain are explored. The glaring effects of brain drain both in the global workforce terrain and specifically in the health sectors are portrayed. The countries affected most and the reasons for brain drain are outlined. Strategic steps to redress the brain drain crisis are proffered in this paper. The health workforce crisis resulting from brain drain must be brought to the front-burner of strategic policy decisions leading to paradigm shift in political, social and economic conditions that would serve as incentives to curb the scourge.

Drain Tube-Induced Jejunal Penetration Masquerading as Bile Leak following Whipple's Operation.

PubMed

Bae, Sang Ho; Lee, Tae Hoon; Lee, Sae Hwan; Lee, Suck-Ho; Park, Sang-Heum; Kim, Sun-Joo; Kim, Chang Ho

2011-05-01

A 70-year-old man had undergone pancreaticoduodenectomy due to a distal common bile duct malignancy. After the operation, serous fluid discharge decreased from two drain tubes in the retroperitoneum. Over four weeks, the appearance of the serous fluid changed to a greenish bile color and the patient persistently drained over 300 ml/day. Viewed as bile leak at the choledochojejunostomy, treatment called for endoscopic diagnosis and therapy. Cap-fitted forward-viewing endoscopy demonstrated that the distal tip of a pancreatic drain catheter inserted at the pancreaticojejunostomy site had penetrated the opposite jejunum wall. One of the drain tubes primarily placed in the retroperitoneum had also penetrated the jejunum wall, with the distal tip positioned near the choledochojejunostomy site. No leak of contrast appeared beyond the jejunum or anastomosis site. Following repositioning of a penetrating catheter of the pancreaticojejunostomy, four days later, the patient underwent removal of two drain tubes without additional complications. In conclusion, the distal tip of the catheter, placed to drain pancreatic juice, penetrated the jejunum wall and may have caused localized perijejunal inflammation. The other drain tube, placed in the retroperitoneal space, might then have penetrated the inflamed wall of the jejunum, allowing persistent bile drainage via the drain tube. The results masqueraded as bile leakage following pancreaticoduodenectomy.

Drain blocking: an effective treatment for reducing dissolved organic carbon loss and water discolouration in a drained peatland.

PubMed

Wallage, Zoe E; Holden, Joseph; McDonald, Adrian T

2006-08-31

Peatlands are an important terrestrial carbon store. However, heightened levels of degradation in response to environmental change have resulted in an increased loss of dissolved organic carbon (DOC) and an associated rise in the level of discolouration in catchment waters. A significant threat to peatland sustainability has been the installation of artificial drainage ditches. However, recent restoration schemes have pursued drain blocking as a possible strategy for reducing degradation, fluvial carbon loss and water discolouration. This paper investigates the effect of open cut drainage and the impact of drain blocking on DOC and colour dynamics in blanket peat soil-water solutions. Three treatments (intact peat, drained peat and drain-blocked peat) were monitored in an upland blanket peat catchment in the UK. DOC and colour values were significantly higher on the drained slopes compared with those of the intact peat, which in turn had greater DOC and colour values than the drain-blocked slopes. Consequently, drain blocking is shown to be a highly successful technique in reducing both the DOC concentration and level of discolouration in soil waters, even to values lower than those observed for the intact site, which suggests a process of store exhaustion and flushing may operate. The colour per carbon unit (C/C) ratio was significantly higher at the drain-blocked site than either the intact or the drained treatments, while the E4/E6 ratio (fulvic acid/humic acid) was significantly lower at the blocked site compared to the two other treatments. The high C/C and low E4/E6 ratios indicate that drain blocking also modifies the composition of DOC, such that darker-coloured humic substances become more dominant compared to the intact site. This implies disturbance to DOC production and/or transportation processes operating within the peat.

Generation of airborne Listeria innocua from model floor drains.

PubMed

Berrang, Mark E; Frank, Joseph F

2012-07-01

Listeria monocytogenes can colonize floor drains in poultry processing and further processing facilities, remaining present even after cleaning and disinfection. Therefore, during wash down, workers exercise caution to avoid spraying hoses directly into drains in an effort to prevent the escape and transfer of drain microflora to food contact surfaces. The objective of this study was to examine the extent to which an inadvertent water spray into a colonized floor drain can cause the spread of airborne Listeria. Listeria innocua was used to inoculate a polyvinyl chloride model floor drain, resulting in approximately 10(8) cells per ml of phosphate-buffered saline and 10(4) attached cells per square centimeter of inner surface. Each model drain was subjected to a 2-s spray of tap water at 68.9 kPa from a distance of 1 m. Drains were sprayed while filled and again after emptying. Airborne cells were collected by using sedimentation plates containing Listeria selective agar which were placed on the floor and walls of a contained room at incremental horizontal and vertical distances of 0.6, 1.2, 2.4, or 4.0 m from the drain. Sedimentation plates were exposed for 10 min. A mechanical sampler was used to also collect air by impaction on the surface of Listeria selective agar to determine the number of cells per liter of air. The experiment was conducted in triplicate rooms for each of four replications. L. innocua was detected on sedimentation plates on the floor as far as 4.0 m from the drain and on walls as high as 2.4 m above the floor and 4 m from the drain. A 2-s spray with a water hose into a contaminated drain can cause airborne spread of Listeria, resulting in the potential for cross-contamination of food contact surfaces, equipment, and exposed product.

Drain placement can be safely omitted after the majority of robotic partial nephrectomies.

PubMed

Abaza, Ronney; Prall, David

2013-03-01

Drain placement after partial nephrectomy is considered standard but it is based on routine and not on evidence. With experience we performed robotic partial nephrectomy and routinely omitted a drain even with significant collecting system violation. We have rarely used drains after robotic partial nephrectomy for several years, and we report our outcomes. We reviewed a single surgeon, prospective database of all robotic partial nephrectomies from February 2008 to March 2012, including the characteristics of those with and without a drain. The 150 patients underwent a total of 160 robotic partial nephrectomy procedures with a drain used in 11 patients and omitted in 93%. Mean patient age was 57 years (range 22 to 89), mean American Society of Anesthesiologists score was 2.8 (range 2 to 4) and mean body mass index was 32 kg/m(2) (range 18 to 54). Values were similar in patients with and without a drain. In patients without a drain and in those with a drain mean tumor size was 3.5 cm (range 1.0 to 11.0) and 4.6 cm (range 1.1 to 8.6), and mean R.E.N.A.L. (radius, exophytic/endophytic, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar lines, hilar tumor touching main renal artery or vein) nephrometry score was 7.8 (range 4 to 12) and 8.8 (range 6 to 11), respectively. Collecting system violation occurred in 88 patients (59%), including 78 without a drain. Two patients (1.3%) required transfusion with no intervention for bleeding. All except 5 patients (97%) were discharged home on postoperative day 1 with all drains removed before discharge. In 2 patients (1.3%) without a drain small urinomas without infection developed more than 2 weeks postoperatively, which were treated with a week of Foley catheter drainage and percutaneous drainage, respectively. Drain placement after robotic partial nephrectomy can be routinely omitted with a low rate of urine leaks, which can be managed safely when they rarely occur. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2012 CFR

2012-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2013 CFR

2013-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2011 CFR

2011-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2014 CFR

2014-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

Responses of Young Slash Pine on Poorly Drained to Somewhat Poorly Drained Silt Loam Soils to Site Preparation and Fertilization Treatments

Treesearch

James D. Haywood

1995-01-01

Slash pines (Pinus elliottii Engelm. var. elliottii) were planted on poorly drained Wrightsville and somewhat poorly drained Vidrine silt loam soils in southwest Louisiana. Neither flat disking nor bedding increased pine growth and yield substantially after nine growing seasons, but broadcast application of triple superphoshate...

7 CFR 58.416 - Cheese vats, tanks and drain tables.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Cheese vats, tanks and drain tables. 58.416 Section 58... Service 1 Equipment and Utensils § 58.416 Cheese vats, tanks and drain tables. (a) The vats, tanks and drain tables used for making cheese should be of metal construction with adequate jacket capacity for...

7 CFR 58.416 - Cheese vats, tanks and drain tables.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Cheese vats, tanks and drain tables. 58.416 Section 58... Service 1 Equipment and Utensils § 58.416 Cheese vats, tanks and drain tables. (a) The vats, tanks and drain tables used for making cheese should be of metal construction with adequate jacket capacity for...

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2010 CFR

2010-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

Method of draining water through a solid waste site without leaching

DOEpatents

Treat, Russell L.; Gee, Glendon W.; Whyatt, Greg A.

1993-01-01

The present invention is a method of preventing water from leaching solid waste sites by preventing atmospheric precipitation from contacting waste as the water flows through a solid waste site. The method comprises placing at least one drain hole through the solid waste site. The drain hole is seated to prevent waste material from entering the drain hole, and the solid waste site cover material is layered and graded to direct water to flow toward the drain hole and to soil beneath the waste site.

Minimally invasive surgical technique for tethered surgical drains

PubMed Central

Hess, Shane R; Satpathy, Jibanananda; Waligora, Andrew C; Ugwu-Oju, Obinna

2017-01-01

A feared complication of temporary surgical drain placement is from the technical error of accidentally suturing the surgical drain into the wound. Postoperative discovery of a tethered drain can frequently necessitate return to the operating room if it cannot be successfully removed with nonoperative techniques. Formal wound exploration increases anesthesia and infection risk as well as cost and is best avoided if possible. We present a minimally invasive surgical technique that can avoid the morbidity associated with a full surgical wound exploration to remove a tethered drain when other nonoperative techniques fail. PMID:28400669

Method of draining water through a solid waste site without leaching

DOEpatents

Treat, R.L.; Gee, G.W.; Whyatt, G.A.

1993-02-02

The present invention is a method of preventing water from leaching solid waste sites by preventing atmospheric precipitation from contacting waste as the water flows through a solid waste site. The method comprises placing at least one drain hole through the solid waste site. The drain hole is seated to prevent waste material from entering the drain hole, and the solid waste site cover material is layered and graded to direct water to flow toward the drain hole and to soil beneath the waste site.

Abdominal drainage following cholecystectomy: high, low, or no suction?

PubMed Central

McCormack, T. T.; Abel, P. D.; Collins, C. D.

1983-01-01

A prospective trial to assess the effect of suction in an abdominal drain following cholecystectomy was carried out. Three types of closed drainage system were compared: a simple tube drain, a low negative pressure drain, and a high negative pressure drain: 120 consecutive patients undergoing cholecystectomy were randomly allocated to one of the three drainage groups. There was no significant difference in postoperative pyrexia, wound infection, chest infection, or hospital stay. This study failed to demonstrate any clinically useful difference between high negative pressure, low negative pressure, and static drainage system were compared: a simple tube drain, a low negative used, suction is not necessary and a simple tube drain (greater than 6 mm internal diameter) is the most effective form of drainage. PMID:6614773

Leakage current conduction in metal gate junctionless nanowire transistors

NASA Astrophysics Data System (ADS)

Oproglidis, T. A.; Karatsori, T. A.; Barraud, S.; Ghibaudo, G.; Dimitriadis, C. A.

2017-05-01

In this paper, the experimental off-state drain leakage current behavior is systematically explored in n- and p-channel junctionless nanowire transistors with HfSiON/TiN/p+-polysilicon gate stack. The analysis of the drain leakage current is based on experimental data of the gate leakage current. It has been shown that the off-state drain leakage current in n-channel devices is negligible, whereas in p-channel devices it is significant and dramatically increases with drain voltage. The overall results indicate that the off-state drain leakage current in p-channel devices is mainly due to trap-assisted Fowler-Nordheim tunneling of electrons through the gate oxide of electrons from the metal gate to the silicon layer near the drain region.

Insights into the history and timing of post-European land use disturbance on sedimentation rates in catchments draining to the Great Barrier Reef.

PubMed

Bartley, Rebecca; Thompson, Chris; Croke, Jacky; Pietsch, Tim; Baker, Brett; Hughes, Kate; Kinsey-Henderson, Anne

2018-06-01

Sediment runoff has been cited as a major contributor to the declining health of the Great Barrier Reef (GBR), however, climate and land use drivers have not been jointly evaluated. This study used alluvial archives from fluvial benches in two tributaries of the Upper Burdekin catchment together with the best available land use history and climate proxy records to provide insights into the timing of depositional events in this region over the past 500 years. This study suggests that mining and the increased runoff variability in the latter half of the nineteenth century are the likely sources of the original excess sediment that was used to build the bench features in these catchments. Grazing also contributed to increased bench sedimentation prior to 1900, however, the contribution of grazing was likely more significant in the second half of the 20th century, and continues to be a dominant land use contributor today. Copyright © 2018 Elsevier Ltd. All rights reserved.

Improved long-term survival with subdural drains following evacuation of chronic subdural haematoma.

PubMed

Guilfoyle, Mathew R; Hutchinson, Peter J A; Santarius, Thomas

2017-05-01

Chronic subdural haematoma (CSDH) is a common condition that is effectively managed by burrhole drainage but requires repeat surgery in a significant minority of patients. The Cambridge Chronic Subdural Haematoma Trial (CCSHT) was a randomised controlled study that showed placement of subdural drains for 48 h following burrhole evacuation significantly reduces the incidence of reoperation and improves survival at 6 months. The present study examined the long-term survival of the patients in the trial. In the original trial patients at a single neurosurgical centre from 2004-2007 were randomly assigned to receive a drain (n = 108) or no drain (n = 107) following burrhole drainage of CSDH. We ascertained whether the trial patients were alive in February 2016-a minimum of 8 years following enrollment-via the UK NHS tracing service. Survival was compared between the trial groups and against expected survival for the UK general population matched for age and sex. At 5 years following surgery the drain group continued to have significantly better survival than the no drain patients (p = 0.027), but this was no longer apparent at 10 years. Survival of patients in the drain group did not differ significantly from that of the general population whereas patients who did not receive a drain had significantly lower survival than expected (p = 0.0006). Subdural drains following CSDH evacuation are associated with improved long-term survival, which appears similar to that expected for the general population of the same age and sex. All patients having burrhole CSDH evacuation should receive a drain as standard practice unless specifically contraindicated.

A novel method for electronic measurement and recording of surgical drain output.

PubMed

van Duren, Bernard Hendrik; van Boxel, Gijsbert Isaac

2017-04-01

Surgical drains are used to collect and measure fluids (e.g. serous fluid, lymph, blood, etc.). The volume of fluid in the container is measured using graded markings on the container and then recorded manually on a "drain chart" allowing for manual rate calculations. This method is dependant on regularly checking the volume of the drain and recording the value accurately; unfortunately, this is often not feasible due to staffing levels and time constraints. This results in inaccurate "drain charts" making clinical decisions based on these figures unreliable. Often the lack of confidence in these measurements leads to delayed drain removal with consequent increased infection risks and potential delayed discharge. Accurate digital measurement of drain content would have a significant impact on clinical care. This paper describes a digital technology to measure volume, making use of a positive terminal at the lowest point of the vessel and negative (sensor) terminals placed at accurate intervals along an axis of the vessel. A proof-of-concept prototype was developed using commercially available electronic components to test the feasibility of a technology for electronic measurement and recording of surgical drain content. In a simulated environment, the proposed technology was shown to be effective and accurate. The proposed electronic drain has a number of advantages over currently used devices in saving time and easing pressure on nursing staff, reduce disturbance of patients, and allows for preset alarms.

Short-Channel Tunneling Field-Effect Transistor with Drain-Overlap and Dual-Metal Gate Structure for Low-Power and High-Speed Operations.

PubMed

Yoon, Young Jun; Eun, Hye Rim; Seo, Jae Hwa; Kang, Hee-Sung; Lee, Seong Min; Lee, Jeongmin; Cho, Seongjae; Tae, Heung-Sik; Lee, Jung-Hee; Kang, In Man

2015-10-01

We have investigated and proposed a highly scaled tunneling field-effect transistor (TFET) based on Ge/GaAs heterojunction with a drain overlap to suppress drain-induced barrier thinning (DIBT) and improve low-power (LP) performance. The highly scaled TFET with a drain overlap achieves lower leakage tunneling current because of the decrease in tunneling events between the source and drain, whereas a typical short-channel TFET suffers from a great deal of tunneling leakage current due to the DIBT at the off-state. However, the drain overlap inevitably increases the gate-to-drain capacitance (Cgd) because of the increase in the overlap capacitance (Cov) and inversion capacitance (Cinv). Thus, in this work, a dual-metal gate structure is additionally applied along with the drain overlap. The current performance and the total gate capacitance (Cgg) of the device with a dual-metal gate can be possibly controlled by adjusting the metal gate workfunction (φgate) and φoverlap-gate in the overlapping regions. As a result, the intrinsic delay time (τ) is greatly reduced by obtaining lower Cgg divided by the on-state current (Ion), i.e., Cgg/Ion. We have successfully demonstrated excellent LP and high-speed performance of a highly scaled TFET by adopting both drain overlap and dual-metal gate with DIBT minimization.

Water table dynamics in undisturbed, drained and restored blanket peat

NASA Astrophysics Data System (ADS)

Holden, J.; Wallage, Z. E.; Lane, S. N.; McDonald, A. T.

2011-05-01

SummaryPeatland water table depth is an important control on runoff production, plant growth and carbon cycling. Many peatlands have been drained but are now subject to activities that might lead to their restoration including the damming of artificial drains. This paper investigates water table dynamics on intact, drained and restored peatland slopes in a blanket peat in northern England using transects of automated water table recorders. Long-term (18 month), seasonal and short-term (storm event) records are explored. The restored site had drains blocked 6 years prior to monitoring commencing. The spatially-weighted mean water table depths over an 18 month period were -5.8 cm, -8.9 cm and -11.5 cm at the intact, restored and drained sites respectively. Most components of water table behaviour at the restored site, including depth exceedance probability curves, seasonality of water table variability, and water table responses to individual rainfall events were intermediate between that of the drained and intact sites. Responses also depended on location with respect to the drains. The results show that restoration of drained blanket peat is difficult and the water table dynamics may not function in the same way as those in undisturbed blanket peat even many years after management intervention. Further measurement of hydrological processes and water table responses to peatland restoration are required to inform land managers of the hydrological success of those projects.

Nurses’ knowledge of care of chest drain: A survey in a Nigerian semiurban university hospital

PubMed Central

Kesieme, Emeka Blessius; Essu, Ifeanyichukwu Stanley; Arekhandia, Bruno Jeneru; Welcker, Katrin; Prisadov, Georgi

2016-01-01

Background/Objective: Inefficient nursing care of chest drains may associated with unacceptable and sometimes life-threatening complications. This report aims to ascertain the level of knowledge of care of chest drains among nurses working in wards in a teaching hospital in Nigeria. Methods: A cross-sectional study among nurses at teaching hospital using pretested self-administered questionnaires. Results: The majority were respondents aged between 31 and 40 years (45.4%) and those who have nursing experience between 6 and 10 years. Only 37 respondents (26.2%) had a good knowledge of nursing care of chest drains. Knowledge was relatively higher among nurses who cared for chest drains daily, nurses who have a work experience of <10 years, low-rank nurses and those working in the female medical ward; however, the relationship cant (P > 0.05). Performance was poor on the questions on position of drainage system were not statistically significant with relationship to waist level while mobilizing the patient, application of suction to chest drains, daily changing of dressing over chest drain insertion site, milking of tubes and drainage system with dependent loop. Conclusion: The knowledge of care of chest drains among nurses is poor, especially in the key post procedural care. There is an urgent need to train them so as to improve the nursing care of patients managed with chest drains. PMID:26857934

Growth and Seed Production of Sawtooth Oak (Quercus acutissima) 22 Years After Direct Seeding

Treesearch

J.C.G. Goelz; D.W. Carlson

1997-01-01

Sawtooth oak (Quercus acutissima Carruth.) was direct seeded at two locations, one with a poorly drained clay soil and the other with a well-drained silty clay loam. For comparison, Nuttall oak (Q. nuttallii Palmer) was direct seeded on the poorly drained clay soil. On the well-drained silty clay loam, sawtooth oak was 18 ft...

Interaction of the Bored Sand and Gravel Drain Pile with the Surrounding Compacted Loam Soil and Foundation Raft Taking into Account Rheological Properties of the Loam Soil and Non-Linear Properties of the Drain Pile

NASA Astrophysics Data System (ADS)

Ter-Martirosyan, Z. G.; Ter-Martirosyan, A. Z.; Anzhelo, G. O.; Buslov, A. S.

2018-01-01

The task of the interaction of the sand and gravel drain pile with the surrounding loam soil after its preliminary deep compaction and formation of the composite ground cylinder from the drain pile and surrounding compacted loam soil (cells) is considered in the article. It is seen that the subsidence and carrying capacity of such cell considerably depends on physical and mechanical properties of the compacted drain piles and surrounding loam soil as well as their diameter and intercellular distance. The strain-stress state of the cell is considered not taking into account its component elements, but taking into account linear and elastic-plastic properties of the drain pile and creep flow of the surrounding loam soil. It is stated that depending on these properties the distribution and redistribution of the load on a cell takes place from the foundation raft between the drain pile and surrounding soil. Based on the results of task solving the formulas and charts are given demonstrating the ratio of the load between the drain pile and surrounding loam soil in time.

Si1-yGey or Ge1-zSnz Source/Drain Stressors on Strained Si1-xGex-Channel P-Type Field-Effect Transistors: A Technology Computer-Aided Design Study

NASA Astrophysics Data System (ADS)

Eneman, Geert; De Keersgieter, An; Witters, Liesbeth; Mitard, Jerome; Vincent, Benjamin; Hikavyy, Andriy; Loo, Roger; Horiguchi, Naoto; Collaert, Nadine; Thean, Aaron

2013-04-01

The interaction between two stress techniques, strain-relaxed buffers (SRBs) and epitaxial source/drain stressors, is studied on short, Si1-xGex- and Ge-channel planar transistors. This work focuses on the longitudinal channel stress generated by these two techniques. Unlike for unstrained silicon-channel transistors, for strained channels on top of a strain-relaxed buffer a source/drain stressor without recess generates similar longitudinal channel stress than source/drain stressors with a deep recess. The least efficient stress transfer is obtained for source/drain stressors with a small recess that removes only the strained channel, not the substrate underneath. These trends are explained by a trade-off between elastic relaxation of the strained-channel during source/drain recess and the increased stress generation of thicker source/drain stressors. For Ge-channel pFETs, GeSn source/drains and Si1-xGex strain-relaxed buffers are efficient stressors for mobility enhancement. The former is more efficient for gate-last schemes than for gate-first, while the stress generated by the SRB is found to be independent of the gate-scheme.

Enhanced performance of amorphous In-Ga-Zn-O thin-film transistors using different metals for source/drain electrodes

NASA Astrophysics Data System (ADS)

Pyo, Ju-Young; Cho, Won-Ju

2017-09-01

In this paper, we propose an amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) with off-planed source/drain electrodes. We applied different metals for the source/drain electrodes with Ni and Ti to control the work function as high and low. When we measured the configuration of Ni to drain and source to Ti, the a-IGZO TFT showed increased driving current, decreased leakage current, a high on/off current ratio, low subthreshold swing, and high mobility. In addition, we conducted a reliability test with a gate bias stress test at various temperatures. The results of the reliability test showed the Ni drain and Ti drain had an equivalent effective energy barrier height. Thus, we confirmed that the proposed off-planed structure improved the electrical characteristics of the fabricated devices without any degradation of characteristics. Through the a-IGZO TFT with different source/drain electrode metal engineering, we realized high-performance TFTs for next-generation display devices.

Necessity of suction drains in gynecomastia surgery.

PubMed

Keskin, Mustafa; Sutcu, Mustafa; Cigsar, Bulent; Karacaoglan, Naci

2014-05-01

The aim of gynecomastia surgery is to restore a normal chest contour with minimal signs of breast surgery. The authors examine the rate of complications in gynecomastia surgery when no closed-suction drains are placed. One hundred thirty-eight consecutive male patients who underwent gynecomastia surgery without drains were retrospectively analyzed to determine whether the absence of drains adversely affected patient outcomes. Patients were managed by ultrasonic-assisted liposuction both with and without the pull-through technique. The mean age of the patients was 29 years, and the mean volume of breast tissue aspirated was 350 mL per beast. Pull-through was needed in 23 cases. There was only 1 postoperative hematoma. These results are comparable with previously published data for gynecomastia surgery in which drains were placed, suggesting that the absence of drains does not adversely affect postoperative recovery. Routine closed-suction drainage after gynecomastia surgery is unnecessary, and it may be appropriate to omit drains after gynecomastia surgery.

Hot-Electron-Induced Device Degradation during Gate-Induced Drain Leakage Stress

NASA Astrophysics Data System (ADS)

Kim, Kwang-Soo; Han, Chang-Hoon; Lee, Jun-Ki; Kim, Dong-Soo; Kim, Hyong-Joon; Shin, Joong-Shik; Lee, Hea-Beoum; Choi, Byoung-Deog

2012-11-01

We studied the interface state generation and electron trapping by hot electrons under gate-induced drain leakage (GIDL) stress in p-type metal oxide semiconductor field-effect transistors (P-MOSFETs), which are used as the high-voltage core circuit of flash memory devices. When negative voltage was applied to a drain in the off-state, a GIDL current was generated, but when high voltage was applied to the drain, electrons had a high energy. The hot electrons produced the interface state and electron trapping. As a result, the threshold voltage shifted and the off-state leakage current (trap-assisted drain junction leakage current) increased. On the other hand, electron trapping mitigated the energy band bending near the drain and thus suppressed the GIDL current generation.

Geochemical baseline studies and relations between water quality and streamflow in the upper Blackfoot Watershed, Montana: data for July 1997-December 1998

USGS Publications Warehouse

Nagorski, Sonia A.; Moore, Johnnie N.; Smith, David B.

2001-01-01

We used ultraclean sampling techniques to study the solute (operationally defined as <0.2 ?m) surface water geochemistry at five sites along the Upper Blackfoot River and four sites along the Landers Fork, some in more detail and more regularly than others. We collected samples also from Hogum Creek, a tributary to the Blackfoot, from Copper Creek, a tributary to the Landers Fork, and from ground water seeps contributing to the flow along the Landers Fork. To better define the physical dynamics of the hydrologic system and to determine geochemical loads, we measured streamflow at all the sites where we took samples for water quality analysis. The Upper Blackfoot River, which drains historic mines ca. 20 Km upstream of the study area, had higher trace metal concentrations than did the Landers Fork, which drains the pristine Scapegoat Wilderness area. In both rivers, many of the major elements were inversely related to streamflow, and at some sites, several show a hysteresis effect in which the concentrations were lower on the rising limb of the hydrograph than on the falling limb. However, many of the trace elements followed far more irregular trends, especially in the Blackfoot River. Elements such as As, Cu, Fe, Mn, S, and Zn exhibited complex and variable temporal patterns, which included almost no response to streamflow differences, increased concentrations following a summer storm and at the start of snowmelt in the spring, and/or increased concentrations throughout the course of spring runoff. In summary, complex interactions between the timing and magnitude of streamflow with physical and chemical processes within the watershed appeared to greatly influence the geochemistry at the sites, and streamflow values alone were not good predictors of solute concentrations in the rivers.

Jet-controlled freeze valve for use in a glass melter

DOEpatents

Routt, K.R.

1985-07-29

A drain valve for use in furnace for the melting of thermoplastic material is disclosed. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace.

Effect of an intervention in storm drains to prevent Aedes aegypti reproduction in Salvador, Brazil.

PubMed

Souza, Raquel Lima; Mugabe, Vánio André; Paploski, Igor Adolfo Dexheimer; Rodrigues, Moreno S; Moreira, Patrícia Sousa Dos Santos; Nascimento, Leile Camila Jacob; Roundy, Christopher Michael; Weaver, Scott C; Reis, Mitermayer Galvão; Kitron, Uriel; Ribeiro, Guilherme Sousa

2017-07-11

Aedes aegypti, the principal vector for dengue, chikungunya and Zika viruses, is a synanthropic species that uses stagnant water to complete its reproductive cycle. In urban settings, rainfall water draining structures, such as storm drains, may retain water and serve as a larval development site for Aedes spp. reproduction. Herein, we describe the effect of a community-based intervention on preventing standing water accumulation in storm drains and their consequent infestation by adult and immature Ae. aegypti and other mosquitoes. Between April and May of 2016, local residents association of Salvador, Brazil, after being informed of water accumulation and Ae. aegypti infestation in the storm drains in their area, performed an intervention on 52 storm drains. The intervention consisted of placing concrete at the bottom of the storm drains to elevate their base to the level of the outflow tube, avoiding water accumulation, and placement of a metal mesh covering the outflow tube to avoid its clogging with debris. To determine the impact of the intervention, we compared the frequency at which the 52 storm drains contained water, as well as adult and immature mosquitoes using data from two surveys performed before and two surveys performed after the intervention. During the pre-intervention period, water accumulated in 48 (92.3%) of the storm drains, and immature Ae. aegypti were found in 11 (21.2%) and adults in 10 (19.2%). After the intervention, water accumulated in 5 (9.6%) of the storm drains (P < 0.001), none (0.0%) had immatures (P < 0.001), and 3 (5.8%) contained adults (P = 0.039). The total number of Ae. aegypti immatures collected decreased from 109 to 0 (P < 0.001) and adults decreased from 37 to 8 (P = 0.011) after the intervention. Collection of immature and adult non-Aedes mosquitoes (mainly Culex spp.) in the storm drains also decreased after the intervention. This study exemplifies how a simple intervention targeting storm drains can result in a major reduction of water retention, and, consequently, impact Ae. aegypti larval populations. Larger and multi-center evaluations are needed to confirm the potential of citywide structural modifications of storm drains to reduce Aedes spp. infestation level.

Digital Map of Surficial Geology, Wetlands, and Deepwater Habitats, Coeur d'Alene River Valley, Idaho

USGS Publications Warehouse

Bookstrom, Arthur A.; Box, Stephen E.; Jackson, Berne L.; Brandt, Theodore R.; Derkey, Pamela D.; Munts, Steven R.

1999-01-01

The Coeur d'Alene (CdA) River channel and its floodplain in north Idaho are mostly covered by metal-enriched sediments, partially derived from upstream mining, milling and smelting wastes. Relative to uncontaminated sediments of the region, metal-enriched sediments are highly enriched in silver, lead, zinc, arsenic, antimony and mercury, copper, cadmium, manganese, and iron. Widespread distribution of metal-enriched sediments has resulted from over a century of mining in the CdA mining district (upstream), poor mine-waste containment practices during the first 80 years of mining, and an ongoing series of over-bank floods. Previously deposited metal-enriched sediments continue to be eroded and transported down-valley and onto the floodplain during floods. The centerpiece of this report is a Digital Map Surficial Geology, Wetlands and Deepwater Habitats of the Coeur d'Alene (CdA) River valley (sheets 1 and 2). The map covers the river, its floodplain, and adjacent hills, from the confluence of the North and South Forks of the CdA River to its mouth and delta front on CdA Lake, 43 linear km (26 mi) to the southwest (river distance 58 km or 36 mi). Also included are the following derivative theme maps: 1. Wetland System Map; 2. Wetland Class Map; 3. Wetland Subclass Map; 4. Floodplain Map; 5. Water Regime Map; 6. Sediment-Type Map; 7. Redox Map; 8. pH Map; and 9. Agricultural Land Map. The CdA River is braided and has a cobble-gravel bottom from the confluence to Cataldo Flats, 8 linear km (5 mi) down-valley. Erosional remnants of up to four alluvial terraces are present locally, and all are within the floodplain, as defined by the area flooded in February of 1996. High-water (overflow) channels and partly filled channel scars braid across some alluvial terraces, toward down-valley marshes and (or) oxbow ponds, which drain back to the river. Near Cataldo Flats, the river gradient flattens, and the river coalesces into a single channel with a large friction-dominated central sand bar at Cataldo Landing. Metal-enriched sediments that were dredged from the central sand bar were deposited on Cataldo Flats, to form extensive dredge-spoil deposits. From the central sand bar to CdA Lake, thick deposits of metal-enriched sand partially fill the middle of the pre-mining-era channel along straight reaches, and form point-bars along the inside margins of meander bends. Metal-enriched sand and silt form oxidized bank-wedge deposits along riverside margins of pre-mining-era levees of gray silty mud. Metal-enriched levee sand deposits extend across bank wedges and natural levees, generally thinning and fining away from the river, toward lateral marshes and lakes, where dark gray metal-enriched silt and mud overlie silty peat, deposited before the mining era. Distributary streams and man-made canals locally diverge from the river, connecting it to lateral marshes and lakes, and metal-enriched sand splays locally fan out across the floodplain. At the mouth of the river, a bouyancy-dominated river-mouth bar crests beyond the ends of the emergent levees. Thick delta-front deposits of metal-enriched sand slope from the river-mouth bar to the bottom of CdA Lake.

Ground-water flow model of the Boone formation at the Tar Creek superfund site, Oklahoma and Kansas

USGS Publications Warehouse

Reed, T.B.; Czarnecki, John B.

2006-01-01

Extensive mining activities conducted at the Tar Creek Superfund site, one of the largest Superfund sites in the United States, pose substantial health and safety risks. Mining activities removed a total of about 6,000,000 tons of lead and zinc by 1949. To evaluate the effect of this mining on the ground-water flow, a MODFLOW 2000 digital model has been developed to simulate ground-water flow in the carbonate formations of Mississippian age underlying the Tar Creek Superfund site. The model consists of three layers of variable thickness and a grid of 580 rows by 680 columns of cells 164 feet (50 meters) on a side. Model flux boundary conditions are specified for rivers and general head boundaries along the northern boundary of the Boone Formation. Selected cells in layer 1 are simulated as drain cells. Model calibration has been performed to minimize the difference between simulated and observed water levels in the Boone Formation. Hydraulic conductivity values specified during calibration range from 1.3 to 35 feet per day for the Boone Formation with the larger values occurring along the axis of the Miami Syncline where horizontal anisotropy is specified as 10 to 1. Hydraulic conductivity associated with the mine void is set at 50,000 feet per day and a specific yield of 1.0 is specified to represent that the mine void is filled completely with water. Residuals (the difference between measured and simulated ground-water altitudes) has a root-mean-squared value of 8.53 feet and an absolute mean value of 7.29 feet for 17 observed values of water levels in the Boone Formation. The utility of the model for simulating and evaluating the possible consequences of remediation activities has been demonstrated. The model was used to simulate the emplacement of chat (mine waste consisting of fines and fragments of chert) back into the mine. Scenarios using 1,800,000 and 6,500,000 tons of chat were run. Hydraulic conductivity was reduced from 50,000 feet per day to 35 feet per day in the model cells corresponding to chat emplacement locations. A comparison of the simulated baseline conditions and conditions after simulated chat emplacement revealed little change in water levels, drainage and stream flux, and ground-water flow velocity. Using the calibrated flow model, particle tracks were simulated using MODPATH to evaluate the simultaneous movement of particles with water in the vicinity of four potential sites at which various volumes of chat might be emplaced in the underground mine workings as part of potential remediation efforts at the site. Particle tracks were generated to follow the rate and direction of water movement for a simulated period of 100 years. In general, chat emplacement had minimal effect on the direction and rate of movement when compared to baseline (current) flow conditions. Water-level differences between baseline and chat-emplacement scenarios showed declines as much as 2 to 3 feet in areas immediately downgradient from the chat emplacement cells and little or no head change upgradient. Chat emplacements had minimal effect on changes in surfacewater flux with the largest simulated difference in one cell between baseline and chat emplacement scenarios being about 3.5 gallons per minute.

Intra-abdominal drain fracture following pancreatic necrosectomy.

PubMed

Campbell, W; Wallace, W; Gibson, E; McCallion, K

2011-06-01

We describe a rare case of iatrogenic fracture of an intra-abdominal tube drain (Portex Robinson drain, Smiths Medical, Kent, UK) in a 74-year-old man. The fracture occurred at the level of an additionally placed fenestration and was identified on CT scanning prior to retrieval at planned re-laparotomy. This case highlights the potential dangers of modifying pre-formed drains and recommends against this practice.

Effectiveness of Postoperative Wound Drains in One- and Two-Level Cervical Spine Fusions

PubMed Central

Poorman, Caroline E.; Bianco, Kristina M.; Boniello, Anthony; Yang, Sun; Gerling, Michael C.

2014-01-01

Background Cervical drains have historically been used to avoid postoperative wound and respiratory complications such as excessive edema, hematoma, infection, re-intubation, delayed extubation, or respiratory distress. Recently, some surgeons have ceased using drains because they may prolong hospital stay, operative time, or patient discomfort. The objective of this retrospective case-control series is to investigate the effectiveness of postoperative drains following one- and two-level cervical fusions. Methods A chart review was conducted at a single institution from 2010-2013. Outcome measures included operative time, hospital stay, estimated blood loss and incidence of wound complications (infection, hematoma, edema, and complications with wound healing or evacuation), respiratory complications (delayed extubation, re-intubation, and respiratory treatment), and overall complications (wound complications, respiratory complications, dysphagia, and other complications). Statistical analyses including independent samples t-test, chi-square, analysis of covariance, and linear regression were used to compare patients who received a postoperative drain to those who did not. Results The study population included 39 patients who received a postoperative drain and 42 patients who did not. There were no differences in demographics between the two groups. Patients with drains showed increased operative time (100.1 vs 69.3 min, p < 0.001), hospital stay (38.9 vs. 31.7 hrs, p = 0.021), and blood loss (62.7 vs 29.1 mL, p < 0.001) compared to patients without drains. The frequency of wound complications, respiratory complications, and overall complications did not vary significantly between groups. Conclusions/Level of Evidence Cervical drains may not be necessary for patients undergoing one- and two-level cervical fusion. While there were no differences in incidence of complications between groups, patients treated with drains had significantly longer operative time and length of hospital stay. Clinical relevance This could contribute to excessive costs for patients treated with drains, despite the lack of compelling evidence of the advantages of this treatment in the literature and in the current study. PMID:25694927

Remote sensing for assessing the zone of benefit where deep drains improve productivity of land affected by shallow saline groundwater.

PubMed

Kobryn, H T; Lantzke, R; Bell, R; Admiraal, R

2015-03-01

The installation of deep drains is an engineering approach to remediate land salinised by the influence of shallow groundwater. It is a costly treatment and its economic viability is, in part, dependent on the lateral extent to which the drain increases biological productivity by lowering water tables and soil salinity (referred to as the drains' zone of benefit). Such zones may be determined by assessing the biological productivity response of adjacent vegetation over time. We tested a multi-temporal satellite remote sensing method to analyse temporal and spatial changes in vegetation condition surrounding deep drainage sites at five locations in the Western Australian wheatbelt affected by dryland salinity-Morawa, Pithara, Beacon, Narembeen and Dumbleyung. Vegetation condition as a surrogate for biological productivity was assessed by Normalised Difference Vegetation Index (NDVI) during the peak growing season. Analysis was at the site scale within a 1000 m buffer zone from the drains. There was clear evidence of NDVI increasing with elevation, slope and distance from the drain. After accounting for elevation, slope and distance from the drain, there was a significant increase in NDVI across the five locations after installation of deep drains. Changes in NDVI after drainage were broadly consistent with measured changes at each site in groundwater levels after installation of the deep drains. However, this study assessed the lateral extent of benefit for biological productivity and gave a measure of the area of benefit along the entire length of the drain. The method demonstrated the utility of spring NDVI images for rapid and relatively simple assessment of the change in site condition after implementation of drainage, but approaches for further improvement of the procedure were identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantification of non-stormwater flow entries into storm drains using a water balance approach.

PubMed

Xu, Zuxin; Yin, Hailong; Li, Huaizheng

2014-07-15

To make decisions about correcting illicit or inappropriate connections to storm drains, quantification of non-stormwater entries into storm drains was performed using a water flow balance approach, based on data analysis from 2008 to 2011 in a separate storm drainage system in a Shanghai downtown area of 374 ha. The study revealed severe sewage connections to storm drains; meanwhile, misconnections between surface water and storm drains were found to drive frequent non-stormwater pumping discharges at the outfall, producing a much larger volume of outfall flows in a short period. This paper presented a methodology to estimate quantities of inappropriate sewage flow, groundwater infiltration and river water backflow into the storm drains. It was concluded that inappropriate sewage discharge and groundwater seepage into storm drains were approximately 17,860 m(3)/d (i.e., up to 51% of the total sewage flow in the catchment) and 3,624 m(3)/d, respectively, and surface water backflow was up to an average 28,593 m(3)/d. On the basis of this work, end-of-storm pipe interceptor sewers of 0.25 m(3)/s (i.e., 21,600 m(3)/d) would be effective to tackle the problem of sewage connections and groundwater seepage to storm drains. Under this circumstance, the follow-up non-stormwater outfall pumping events indicate misconnections between surface water and storm drains, featuring pumping discharge equivalent to surface water backflow; hence the misconnections should be repaired. The information provided here is helpful in estimating the magnitude of non-stormwater flow entries into storm drains and designing the necessary pollution control activities, as well as combating city floods in storm events. Copyright © 2014. Published by Elsevier B.V.

Continuous 'Passive' Registration of Non-Point Contaminant Loads Via Agricultural Subsurface Drain Tubes

NASA Astrophysics Data System (ADS)

Rozemeijer, J.; Jansen, S.; de Jonge, H.; Lindblad Vendelboe, A.

2014-12-01

Considering their crucial role in water and solute transport, enhanced monitoring and modeling of agricultural subsurface tube drain systems is important for adequate water quality management. For example, previous work in lowland agricultural catchments has shown that subsurface tube drain effluent contributed up to 80% of the annual discharge and 90-92% of the annual NO3 loads from agricultural fields towards the surface water. However, existing monitoring techniques for flow and contaminant loads from tube drains are expensive and labor-intensive. Therefore, despite the unambiguous relevance of this transport route, tube drain monitoring data are scarce. The presented study aimed developing a cheap, simple, and robust method to monitor loads from tube drains. We are now ready to introduce the Flowcap that can be attached to the outlet of tube drains and is capable of registering total flow, contaminant loads, and flow-averaged concentrations. The Flowcap builds on the existing SorbiCells, a modern passive sampling technique that measures average concentrations over longer periods of time (days to months) for various substances. By mounting SorbiCells in our Flowcap, a flow-proportional part of the drain effluent is sampled from the main stream. Laboratory testing yielded good linear relations (R-squared of 0.98) between drainage flow rates and sampling rates. The Flowcap was tested in practice for measuring NO3 loads from two agricultural fields and one glasshouse in the Netherlands. The Flowcap registers contaminant loads from tube drains without any need for housing, electricity, or maintenance. This enables large-scale monitoring of non-point contaminant loads via tube drains, which would facilitate the improvement of contaminant transport models and would yield valuable information for the selection and evaluation of mitigation options to improve water quality.

Quantification of metal loads by tracer injection and synoptic sampling in Daisy Creek and the Stillwater River, Park County, Montana, August 1999

USGS Publications Warehouse

Nimick, David A.; Cleasby, Thomas E.

2001-01-01

A metal-loading study using tracer-injection and synoptic-sampling methods was conducted in Daisy Creek and a short reach of the Stillwater River during baseflow in August 1999 to quantify the metal inputs from acid rock drainage in the New World Mining District near Yellowstone National Park and to examine the downstream transport of these metals into the Stillwater River. Loads were calculated for many mainstem and inflow sites by combining streamflow determined using the tracer-injection method with concentrations of major ions and metals that were determined in synoptic water-quality samples. Water quality and aquatic habitat in Daisy Creek have been affected adversely by drainage derived from waste rock and adit discharge at the McLaren Mine as well as from natural weathering of pyrite-rich mineralized rock that comprises and surrounds the ore zones. However, the specific sources and transport pathways are not well understood. Knowledge of the main sources and transport pathways of metals and acid can aid resource managers in planning and conducting effective and cost-efficient remediation activities. The metals cadmium, copper, lead, and zinc occur at concentrations that are sufficiently elevated to be potentially lethal to aquatic life in Daisy Creek and to pose a toxicity risk in part of the Stillwater River. Copper is of most concern in Daisy Creek because it occurs at higher concentrations than the other metals. Acidic surface inflows had dissolved concentrations as high as 20.6 micrograms per liter (?g/L) cadmium, 26,900 ?g/L copper, 76.4 ?g/L lead, and 3,000 ?g/L zinc. These inflows resulted in maximum dissolved concentrations in Daisy Creek of 5.8 ?g/L cadmium, 5,790 ?g/L copper, 3.8 ?g/L lead, and 848 ?g/L zinc. Significant copper loading to Daisy Creek occurred only in the upper half of the stream. Sources included subsurface inflow and right-bank (mined side) surface inflows. Copper loads in left-bank (unmined side) surface inflows were negligible. Most (71 percent) of the total copper loading in the study reach occurred along a 341-foot reach near the stream?s headwaters. About 53 percent of the total copper load was contributed by five surface inflows that drain a manganese bog and the southern part of the McLaren Mine. Copper loading from subsurface inflow was substantial, contributing 46 percent of the total dissolved copper load to Daisy Creek. More than half of this subsurface copper loading occurred downstream from the reaches that received significant surface loading. Flow through the shallow subsurface appears to be the main copper-transport pathway from the McLaren Mine and surrounding altered and mineralized bedrock to Daisy Creek during base-flow conditions. Little is known about the source of acid and copper in this subsurface flow. However, possible sources include the mineralized rocks of Fisher Mountain upgradient of the McLaren Mine area, the surficial waste rock at the mine, and the underlying pyritic bedrock.

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

The fabrication of carbon nanotube field-effect transistors with semiconductors as the source and drain contact materials.

PubMed

Xiao, Z; Camino, F E

2009-04-01

Sb(2)Te(3) and Bi(2)Te(2)Se semiconductor materials were used as the source and drain contact materials in the fabrication of carbon nanotube field-effect transistors (CNTFETs). Ultra-purified single-walled carbon nanotubes (SWCNTs) were ultrasonically dispersed in N-methyl pyrrolidone solvent. Dielectrophoresis was used to deposit and align SWCNTs for fabrication of CNTFETs. The Sb(2)Te(3)- and Bi(2)Te(2)Se-based CNTFETs demonstrate p-type metal-oxide-silicon-like I-V curves with high on/off drain-source current ratio at large drain-source voltages and good saturation of drain-source current with increasing drain-source voltage. The fabrication process developed is novel and has general meaning, and could be used for the fabrication of SWCNT-based integrated devices and systems with semiconductor contact materials.

Cannulation for veno-venous extracorporeal membrane oxygenation

PubMed Central

2018-01-01

Extracorporeal membrane oxygenation (ECMO) is described as a modified, smaller cardiopulmonary bypass circuit. The veno-venous (VV) ECMO circuit drains venous blood, oxygenate the blood, and pump the blood back into the same venous compartment. Draining and reinfusing in the same compartment means there are a risk of recirculation. The draining position within the venous system, ECMO pump flow, return flow position within the venous system and the patients cardiac output (CO) all have an impact on recirculation. Using two single lumen cannulas or one dual lumen cannula, but also the design of the venous cannula, can have an impact on where within the venous system the cannula is draining blood and will affect the efficiency of the ECMO circuit. VV ECMO can be performed with different cannulation strategies. The use of two single lumen cannulas draining in inferior vena cava (IVC) and reinfusing in superior vena cava (SVC) or draining in SVC and reinfusing in IVC, or one dual lumen cannula inserted in right jugular vein is all possible cannulation strategies. Independent of cannulation strategy there will be a risk of recirculation. Efficiency can be reasonable in either strategy if the cannulas are carefully positioned and monitored during the dynamic procedure of pulmonary disease. The disadvantage draining from IVC only occurs when there is a need for converting from VV to veno-arterial (VA) ECMO, reinfusing in the femoral artery. Then draining from SVC is the most efficient strategy, draining low saturated venous blood, and also means low risk of dual circulation. PMID:29732177

Comparison consequences of Jackson-Pratt drain versus chest tube after coronary artery bypass grafting: A randomized controlled clinical trial.

PubMed

Mirmohammad-Sadeghi, Mohsen; Pourazari, Pejman; Akbari, Mojtaba

2017-01-01

Chest tubes are used in every case of coronary artery bypass grafting (CABG) to evacuate shed blood from around the heart and lungs. This study was designed to assess the effective of Jackson-Pratt drain in compare with conventional chest drains after CABG. This was a randomized controlled trial that conducted on 218 patients in Chamran hospital from February to December 2016. Eligible patients were randomized in a 1:1 ratio. Jackson-Pratt drain group had 109 patients who received a chest tube insertion in the pleural space of the left lung and a Jackson-Pratt drain in mediastinum, and Chest tube drainage group had 109 patients who received double chest tube insertion in the pleural space of the left lung and the mediastinum. The incidence of pleural effusions in Jackson-Pratt drain group and chest tube group were not statistically different. The pain score at 2-h in Drain group was significantly higher than chest tube group ( P = 0.001), but the trend of pain score between groups was not significantly different ( P = 0.097). The frequency of tamponade and atrial fibrillation (AF) were significantly lower in Jackson-Pratt drain group ( P < 0.05). The Jackson-Pratt drain is equally effective for preventing cardiac tamponade, pleural effusions, and pain intensity in patients after CABG when compared with conventional chest tubes, but was significantly superior regarding efficacy to hospital and Intensive Care Unit length of stay and the incidence of AF.

Integrated Water Basin Management Including a Large Pit Lake and a Water Supply Reservoir: The Mero-Barcés Basin

NASA Astrophysics Data System (ADS)

Delgado, Jordi; Juncosa-Rivera, Ricardo; Hernández-Anguiano, Horacio; Muñoz-Ibáñez, Andrea

2016-04-01

Water resource managers attempt to minimize conflicts among users, preserve the environment as much as possible, and satisfy user necessities at a minimum cost. Several European directives indirectly address mine restoration policies, with a goal of minimizing negative impacts and adding social and environmental value where possible. Water management must consider water sources, ecological flows, flood control, and variability in the demands for urban, industrial, and agricultural uses. In the context of the present study, the city of A Coruña is located in Galicia (NW Spain). The water supply system for this city and surrounding municipalities (~400.000 inhabitants) is based on the Abegondo-Cecebre reservoir. In cases when precipitation is scarce (e.g. no rain for more than seven consecutive months) and there is a seasonal increase in demand significantly stress the supply system so that, as occurred in 2010, shortages and water supply restrictions need to be considered. This is a clear indication of that, at present, the Abegondo-Cecebre reservoir has not enough capacity to cope with a scenario of increasing water demand (due to the vegetative and seasonal increase of population) and hydric stress likely connected with the widely acknowledged climate change. In the present context of monetary resources scarcity and society concern with respect large new public work projects, the construction of a new dam is challenging. However the opportunity provided by the recent flooding of the Meirama open pit (a large mine void that has been forced-flooded for its reclamation and it is located in the headwaters of one of the rivers draining towards the Abegondo-Cecebre reservoir) proves to be a significant new asset that will help to improve the future water management scenarios under the acknowledged uncertain conditions. In this study we have studied in detail the hydrochemistry of the affected systems (lake, river and reservoir) in order to make clear whether or not the use of lake water is acceptable from different points of view (water quality, legal constrains, etc.). Our results indicate that the joint use of the lake/reservoir system is feasible. Based on this and other complementary study, the basin water authorities has developed a project by which a 2.1 km uptake tunnel will be excavated in the next years to drain water from the lake towards the Barcés river and complement the water supply necessities of the Abegondo-Cecebre reservoir in case of hydric emergencies.

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

USGS Publications Warehouse

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

2009-01-01

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

Carbon Dioxide Flux from Rice Paddy Soils in Central China: Effects of Intermittent Flooding and Draining Cycles

PubMed Central

Liu, Yi; Wan, Kai-yuan; Tao, Yong; Li, Zhi-guo; Zhang, Guo-shi; Li, Shuang-lai; Chen, Fang

2013-01-01

A field experiment was conducted to (i) examine the diurnal and seasonal soil carbon dioxide (CO2) fluxes pattern in rice paddy fields in central China and (ii) assess the role of floodwater in controlling the emissions of CO2 from soil and floodwater in intermittently draining rice paddy soil. The soil CO2 flux rates ranged from −0.45 to 8.62 µmol.m−2.s−1 during the rice-growing season. The net effluxes of CO2 from the paddy soil were lower when the paddy was flooded than when it was drained. The CO2 emissions for the drained conditions showed distinct diurnal variation with a maximum efflux observed in the afternoon. When the paddy was flooded, daytime soil CO2 fluxes reversed with a peak negative efflux just after midday. In draining/flooding alternating periods, a sudden pulse-like event of rapidly increasing CO2 efflux occured in response to re-flooding after draining. Correlation analysis showed a negative relation between soil CO2 flux and temperature under flooded conditions, but a positive relation was found under drained conditions. The results showed that draining and flooding cycles play a vital role in controlling CO2 emissions from paddy soils. PMID:23437170

Drain amylase aids detection of anastomotic leak after esophagectomy.

PubMed

Baker, Erin H; Hill, Joshua S; Reames, Mark K; Symanowski, James; Hurley, Susie C; Salo, Jonathan C

2016-04-01

Anastomotic leak following esophagectomy is associated with significant morbidity and mortality. As hospital length of stay decreases, the timely diagnosis of leak becomes more important. We evaluated CT esophagram, white blood count (WBC), and drain amylase levels in the early detection of anastomotic leak. The diagnostic performance of CT esophagram, drain amylase >800 IU/L, and WBC >12,000/µL within the first 10 days after surgery in predicting leak at any time after esophagectomy was calculated. Anastomotic leak occurred in 13 patients (13%). CT esophagram performed within 10 days of surgery diagnosed six of these leaks with a sensitivity of 0.54. Elevation in drain amylase level within 10 days of surgery diagnosed anastomotic leak with a sensitivity of 0.38. When the CT esophagram and drain amylase were combined, the sensitivity rose to 0.69 with a specificity of 0.98. WBC elevation had a sensitivity of 0.92, with a specificity of 0.34. Among 30 patients with normal drain amylase and a normal WBC, one developed an anastomotic leak. Drain amylase adds to the sensitivity of CT esophagram in the early detection of anastomotic leak. Selected patients with normal drain amylase levels and normal WBC may be able to safely forgo CT esophagram.

Placement of percutaneous transhepatic biliary stent using a silicone drain with channels

PubMed Central

Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Mineta, Sho; Mizuguchi, Yoshiaki; Kawano, Yoichi; Sasaki, Junpei; Nakamura, Yoshiharu; Aimoto, Takayuki; Tajiri, Takashi

2009-01-01

This report describes a method for percutaneous transhepatic biliary stenting with a BLAKE Silicone Drain, and discusses the usefulness of placement of the drain connected to a J-VAC Suction Reservoir for the treatment of stenotic hepaticojejunostomy. Percutaneous transhepatic biliary drainage was performed under ultrasonographic guidance in a patient with stenotic hepaticojejunostomy after hepatectomy for hepatic hilum malignancy. The technique used was as follows. After dilatation of the drainage root, an 11-Fr tube with several side holes was passed through the stenosis of the hepaticojejunostomy. A 10-Fr BLAKE Silicone Drain is flexible, which precludes one-step insertion. One week after insertion of the 11-Fr tube, a 0.035-inch guidewire was inserted into the tube. After removal of the 11-Fr tube, the guidewire was put into the channel of a 10-Fr BLAKE Silicone Drain. The drain was inserted into the jejunal limb through the intrahepatic bile duct and was connected to a J-VAC Suction Reservoir. Low-pressure continued suction was applied. Patients can be discharged after insertion of the 10-Fr BLAKE Silicone Drain connected to the J-VAC Suction Reservoir. Placement of a percutaneous transhepatic biliary stent using a 10-Fr BLAKE Silicone Drain connected to a J-VAC Suction Reservoir is useful for the treatment of stenotic hepaticojejunostomy. PMID:19725159

Assessment of water resources in lead-zinc mined areas in Cherokee County, Kansas, and adjacent areas

USGS Publications Warehouse

Spruill, Timothy B.

1987-01-01

A study was conducted to evaluate water-resources problems related to abandoned lead and zinc mines in Cherokee County, Kansas, and adjacent areas in Missouri and Oklahoma. Past mining activities have caused changes in the hydrogeology of the area. Lead and zinc mining has caused discontinuities and perforations in the confining shale west of the Pennsylvanian-Mississippian geologic contact (referred to as the western area), which have created artificial ground-water recharge and discharge areas. Recharge to the shallow aquifer (rocks of Mississippian age) through collapses, shafts, and drill holes in the shale has caused the formation of a ground-water 'mound' in the vicinity of the Picher Field in Kansas and Oklahoma. Discharge of mine-contaminated ground water to Tar Creek occurs in Oklahoma from drill holes and shafts where the potentiometric surface of the shallow aquifer is above the land surface. Mining of ore in the shallow aquifer has resulted in extensive fracturing and removal of material, which has created highly transmissive zones and voids and increased ground-water storage properties of the aquifer. In the area east of the Pennsylvanian-Mississippian geologic contact (referred to as the eastern area), fractured rock and tailings on the land surface increased the amount of water available for infiltration to the shallow aquifer; in the western area, tailings on the impermeable shale created artificial, perched aquifer systems that slowly drain to surface streams. Pumping of the deep aquifer (rocks of Cambrian and Ordovician age) by towns and industries, which developed as a result of the mining industry, has resulted in a potential for downward movement of water from the shallow aquifer. The potential is greatest in Ottawa County, Oklahoma. Because of the large volume of water that may be transported from the shallow to the deep aquifer, open drill holes or casings present the greatest contamination hazard to water supplies in the deep aquifer. Mining allowed oxidation of ore deposits which, on saturation with water, resulted in poor-quality water that generally contains large concentrations of sulfate and trace metals. Water from mines in the eastern area contained dissolved-solids concentrations of less than 500 mg/L (milligrams per liter), a median pH of 3.9, sulfate concentrations that ranged between 98 and 290 mg/L, and median concentrations for zinc of 37,600 micrograms/L (micrograms per liter), for lead of 240 micrograms/L, for cadmium of 180 micrograms/L, for iron of 70 micrograms/L, for manganese of 240 micrograms/L, and for silica of 15 mg/L. Water from mines in the western area contained dissolved-solids concentrations of generally more than 500 mg/L, a median pH of 6.8, sulfate concentrations that ranged between 170 and 2,150 mg/L, and median concentrations for zinc of 3,200 micrograms/L, for lead of 0 micrograms/L (minimum detection limit is 10 micrograms/L), for cadmium of 6 micrograms/L, for iron of 840 micrograms/L, for manganese of 440 micrograms/L, and for silica of 11 mg/L. No conclusive evidence of lateral migration of water from the mines into domestic well-water supplies in the shallow aquifer was found in the study area in Kansas. Analyses of water from public-supply wells tapping the deep aquifer did not indicate contamination with trace metals, although chemical analyses from four of six wells exhibited increasing trends through time in sulfate concentrations. These increases probably reflect localized leakage of water from the shallow aquifer along corroded or leaky well casings. Effects of abandoned lead and zinc mines on tributaries of the Spring River in the eastern area are most severe in Short Creek. Compared with water samples from three other major streams in the eastern area, a sample collected from Short Creek, 2 miles west of Galena, Kansas, during August 1981, contained the largest concentrations of dissolved sulfate (240 mg/L), zinc (25,000 micrograms/L), ca

Thoracic Trauma: Which Chest Tube When and Where?

PubMed

Molnar, Tamas F

2017-02-01

Clinical suspicion of hemo/pneumothorax: when in doubt, drain the chest. Stable chest trauma with hemo/pneumothorax: drain and wait. Unstable patient with dislocated trachea must be approached with drain in hand and scalpel ready. Massive hemo/pneumothorax may be controlled by drainage alone. The surgeon should not hesitate to open the chest if too much blood drains over a short period. The chest drainage procedure does not end with the last stitch; the second half of the match is still ahead. The drained patient is in need of physiotherapy and proper pain relief with an extended pleural space: control the suction system. Copyright © 2016 Elsevier Inc. All rights reserved.

Numerical Simulation of Liquids Draining From a Tank Using OpenFOAM

NASA Astrophysics Data System (ADS)

Sakri, Fadhilah Mohd; Sukri Mat Ali, Mohamed; Zaki Shaikh Salim, Sheikh Ahmad; Muhamad, Sallehuddin

2017-08-01

Accurate simulation of liquids draining is a challenging task. It involves two phases flow, i.e. liquid and air. In this study draining a liquid from a cylindrical tank is numerically simulated using OpenFOAM. OpenFOAM is an open source CFD package and it becomes increasingly popular among the academician and also industries. Comparisons with theoretical and results from previous published data confirmed that OpenFOAM is able to simulate the liquids draining very well. This is done using the gas-liquid interface solver available in the standard library of OpenFOAM. Additionally, this study was also able to explain the physics flow of the draining tank.

Closed flume inlet efficiency : [summary].

DOT National Transportation Integrated Search

2014-04-01

The storm drain is an inconspicuous but critical : part of the roadway, especially in Florida. Drains : look deceptively simple, but they must capture : water as efficiently as possible. To help assure : the performance of storm drains, the Florida :...

Statistical variability study of random dopant fluctuation on gate-all-around inversion-mode silicon nanowire field-effect transistors

NASA Astrophysics Data System (ADS)

Yoon, Jun-Sik; Rim, Taiuk; Kim, Jungsik; Kim, Kihyun; Baek, Chang-Ki; Jeong, Yoon-Ha

2015-03-01

Random dopant fluctuation effects of gate-all-around inversion-mode silicon nanowire field-effect transistors (FETs) with different diameters and extension lengths are investigated. The nanowire FETs with smaller diameter and longer extension length reduce average values and variations of subthreshold swing and drain-induced barrier lowering, thus improving short channel immunity. Relative variations of the drain currents increase as the diameter decreases because of decreased current drivability from narrower channel cross-sections. Absolute variations of the drain currents decrease critically as the extension length increases due to decreasing the number of arsenic dopants penetrating into the channel region. To understand variability origins of the drain currents, variations of source/drain series resistance and low-field mobility are investigated. All these two parameters affect the variations of the drain currents concurrently. The nanowire FETs having extension lengths sufficient to prevent dopant penetration into the channel regions and maintaining relatively large cross-sections are suggested to achieve suitable short channel immunity and small variations of the drain currents.

Cleanup Verification Package for the 118-H-6:2, 105-H Reactor Ancillary Support Areas, Below-Grade Structures, and Underlying Soils; the 118-H-6:3, 105-H Reactor Fuel Storage Basin and Underlying Soils; The 118-H-6:3 Fuel Storage Basin Deep Zone Side Slope Soils; the 100-H-9, 100-H-10, and 100-H-13 French Drains; the 100-H-11 and 100-H-12 Expansion Box French Drains; and the 100-H-14 and 100-H-31 Surface Contamination Zones

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

M. J. Appel

2006-06-29

This cleanup verification package documents completion of removal actions for the 105-H Reactor Ancillary Support Areas, Below-Grade Structures, and Underlying Soils (subsite 118-H-6:2); 105-H Reactor Fuel Storage Basin and Underlying Soils (118-H-6:3); and Fuel Storage Basin Deep Zone Side Slope Soils. This CVP also documents remedial actions for the following seven additional waste sties: French Drain C (100-H-9), French Drain D (100-H-10), Expansion Box French Drain E (100-H-11), Expansion Box French Drain F (100-H-12), French Drain G (100-H-13), Surface Contamination Zone H (100-H-14), and the Polychlorinated Biphenyl Surface Contamination Zone (100-H-31).

Randomised clinical trial of chest drainage systems.

PubMed Central

Graham, A N; Cosgrove, A P; Gibbons, J R; McGuigan, J A

1992-01-01

BACKGROUND: Problems in the management of thoracic trauma have stimulated the search for an alternative to underwater seals for drainage of the pleural cavity. A chest drainage bag incorporating a one way flutter valve has been compared with underwater seal drains in a randomised clinical trial. METHODS: During June-December 1989 119 patients undergoing elective thoracotomy were randomised to receive postoperative chest drainage by drainage bags (56 patients, 87 drains) or by underwater seal drains (63 patients, 98 drains). Daily drainage volumes, the requirement for pleural suction, mobility, and complications were recorded prospectively. RESULTS: There was no significant difference between the two groups in the mean volume drained, the requirements for pleural suction, or the occurrence of complications. Patients with drainage bags were fully mobile 23 hours (95% confidence interval 0-47 hours) earlier than the others. CONCLUSIONS: When used after elective thoracotomy drainage bags are safe and effective and permit earlier mobility than underwater seal drains. PMID:1496507

p-MOSFET total dose dosimeter

NASA Technical Reports Server (NTRS)

Buehler, Martin G. (Inventor); Blaes, Brent R. (Inventor)

1994-01-01

A p-MOSFET total dose dosimeter where the gate voltage is proportional to the incident radiation dose. It is configured in an n-WELL of a p-BODY substrate. It is operated in the saturation region which is ensured by connecting the gate to the drain. The n-well is connected to zero bias. Current flow from source to drain, rather than from peripheral leakage, is ensured by configuring the device as an edgeless MOSFET where the source completely surrounds the drain. The drain junction is the only junction not connected to zero bias. The MOSFET is connected as part of the feedback loop of an operational amplifier. The operational amplifier holds the drain current fixed at a level which minimizes temperature dependence and also fixes the drain voltage. The sensitivity to radiation is made maximum by operating the MOSFET in the OFF state during radiation soak.

Corrective Action Plan for Corrective Action Unit 562: Waste Systems, Nevada National Security Site, Nevada

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

NSTec Environmental Restoration

2011-04-30

This Corrective Action Plan has been prepared for Corrective Action Unit (CAU) 562, Waste Systems, in accordance with the Federal Facility Agreement and Consent Order (1996; as amended March 2010). CAU 562 consists of 13 Corrective Action Sites (CASs) located in Areas 2, 23, and 25 of the Nevada National Security Site. Site characterization activities were performed in 2009 and 2010, and the results are presented in Appendix A of the Corrective Action Decision Document for CAU 562. The scope of work required to implement the recommended closure alternatives is summarized. (1) CAS 02-26-11, Lead Shot, will be clean closedmore » by removing shot. (2) CAS 02-44-02, Paint Spills and French Drain, will be clean closed by removing paint and contaminated soil. As a best management practice (BMP), asbestos tile will be removed. (3) CAS 02-59-01, Septic System, will be clean closed by removing septic tank contents. As a BMP, the septic tank will be removed. (4) CAS 02-60-01, Concrete Drain, contains no contaminants of concern (COCs) above action levels. No further action is required; however, as a BMP, the concrete drain will be removed. (5) CAS 02-60-02, French Drain, was clean closed. Corrective actions were completed during corrective action investigation activities. As a BMP, the drain grates and drain pipe will be removed. (6) CAS 02-60-03, Steam Cleaning Drain, will be clean closed by removing contaminated soil. As a BMP, the steam cleaning sump grate and outfall pipe will be removed. (7) CAS 02-60-04, French Drain, was clean closed. Corrective actions were completed during corrective action investigation activities. (8) CAS 02-60-05, French Drain, will be clean closed by removing contaminated soil. (9) CAS 02-60-06, French Drain, contains no COCs above action levels. No further action is required. (10) CAS 02-60-07, French Drain, requires no further action. The french drain identified in historical documentation was not located during corrective action investigation activities. (11) CAS 23-60-01, Mud Trap Drain and Outfall, will be clean closed by removing sediment from the mud trap. As a BMP, the mud trap and outfall pipe will be removed. (12) CAS 23-99-06, Grease Trap, will be clean closed by removing sediment from the grease trap and backfilling the grease trap with grout. (13) CAS 25-60-04, Building 3123 Outfalls, will be clean closed by removing contaminated soil and the sludge-containing outfall pipe.« less

Comparative Evaluation of Immediate Post-Operative Sequelae after Surgical Removal of Impacted Mandibular Third Molar with or without Tube Drain - Split-Mouth Study.

PubMed

Kumar, Barun; Bhate, Kalyani; Dolas, R S; Kumar, Sn Santhosh; Waknis, Pushkar

2016-12-01

Third molar surgery is one of the most common surgical procedures performed in general dentistry. Post-operative variables such as pain, swelling and trismus are major concerns after impacted mandibular third molar surgery. Use of passive tube drain is supposed to help reduce these immediate post-operative sequelae. The current study was designed to compare the effect of tube drain on immediate post-operative sequelae following impacted mandibular third molar surgery. To compare the post-operative sequelae after surgical removal of impacted mandibular third molar surgery with or without tube drain. Thirty patients with bilateral impacted mandibular third molars were divided into two groups: Test (with tube drain) and control (without tube drain) group. In the test group, a tube drain was inserted through the releasing incision, and kept in place for three days. The control group was left without a tube drain. The post-operative variables like, pain, swelling, and trismus were calculated after 24 hours, 72 hours, 7 days, and 15 days in both the groups and analyzed statistically using chi-square and t-test analysis. The test group showed lesser swelling as compared to control group, with the swelling variable showing statistically significant difference at post-operative day 3 and 7 (p≤ 0.05) in both groups. There were no statistically significant differences in pain and trismus variables in both the groups. The use of tube drain helps to control swelling following impacted mandibular third molar surgery. However, it does not have much effect on pain or trismus.

Abdominal Drainage and Amylase Measurement for Detection of Leakage After Gastrectomy for Gastric Cancer.

PubMed

Schots, Judith P M; Luyer, Misha D P; Nieuwenhuijzen, Grard A P

2018-05-07

To investigate the value of daily measurement of drain amylase for detecting leakage in gastric cancer surgery. This was a retrospective analysis including all patients who underwent a gastrectomy for gastric cancer. From January 2013 until December 2015, an intra-abdominal drain was routinely placed. Drain amylase was measured daily. Receiver operator characteristic curves were created to assess the ability of amylase to predict leakage. Sensitivity, specificity, and negative and positive predictive value of amylase in drain fluid were determined. Leakage of the gastrojejunostomy or esophagojejunostomy, enteroenterostomy, duodenal stump, or pancreas was diagnosed by CT scan, endoscopy, or during re-operation. From January 2016 until April 2017, no drain was inserted. Surgical outcome and postoperative complications were compared between both groups. Median drain amylase concentrations were higher for each postoperative day in patients with leakage. The optimal cutoff value was 1000 IU/L (sensitivity 77.8%, specificity 98.2%, negative predictive value 96.6%). Sixty-seven consecutive procedures were performed with a drain and 40 procedures without. No differences in group characteristics were observed except for gender. Fourteen patients (13.1%) had a leakage. The incidence and severity of leakage were not different between the patients with and without a drain. There was no significant difference in time to diagnosis (1 vs. 0 days; p 0.34), mortality rate (7.5 vs. 2.5%; p 0.41), and median length of hospital stay (9 days in both groups; p 0.46). Daily amylase measurement in drain fluid does not influence the early recognition and management of leakage in gastric cancer surgery.

Current practice patterns of drain usage amongst UK and Irish surgeons performing bilateral breast reductions: Evidence down the drain.

PubMed

Sugrue, Conor M; McInerney, Niall; Joyce, Cormac W; Jones, Deidre; Hussey, Alan J; Kelly, Jack L; Kerin, Michael J; Regan, Padraic J

2015-01-01

Bilateral breast reduction (BBR) is one of the most frequently performed female breast operations. Despite no evidence supporting efficacy of drain usage in BBRs, postoperative insertion is common. Recent high quality evidence demonstrating potential harm from drain use has subsequently challenged this traditional practice. The aim of this study is to assess the current practice patterns of drains usage by Plastic & Reconstructive and Breast Surgeons in UK and Ireland performing BBRs. An 18 question survey was created evaluating various aspects of BBR practice. UK and Irish Plastic & Reconstructive and Breast Surgeons were invited to participate by an email containing a link to a web-based survey. Statistical analysis was performed with student t-test and chi-square test. Two hundred and eleven responding surgeons were analysed, including 80.1% (171/211) Plastic Surgeons and 18.9% (40/211) Breast Surgeons. Of the responding surgeons, 71.6% (151/211) routinely inserted postoperative drains, for a mean of 1.32 days. Drains were used significantly less by surgeons performing ≥20 BBRs (p = 0.02). With the majority of BBRs performed as an inpatient procedure, there was a trend towards less drain usage in surgeons performing this procedure as an outpatient; however, this was not statistically significant (p = 0.07). Even with the high level of evidence demonstrating the safety of BBR without drains, they are still routinely utilised. In an era of evidence- based medicine, surgeons performing breast reductions must adopt the results from scientific research into their clinical practice.

Multiple variations of the renal and testicular vessels: possible embryological basis and clinical importance.

PubMed

Mazengenya, Pedzisai

2016-08-01

During routine dissection of the abdominal cavity of a 55-year-old African male cadaver, multiple anomalies including renal and testicular vessels were encountered. The right kidney was supplied by three right hilar renal arteries arising from the abdominal aorta at different vertebral levels whereas only one left renal artery supplied the left kidney. On the right three renal veins drained the kidney into the inferior vena cava. In contrast, the left kidney was drained by a single renal vein which received a large primary posterior tributary. The primary posterior tributary had three tributaries from the posterior lumbar region. The right testis had two sources of arterial supply; one from the subcostal artery and another from the abdominal aorta. The left testis was supplied normally by a single testicular artery. The right testis was drained by four testicular veins as follows: one drained into the subcostal vein, the other two drained separately for a longer course and joined shortly before draining into the right main renal vein, the fourth one drained into the anterior aspect of the inferior vena cava at the level of the second lumbar vertebra. On the left, the testicle was drained by two testicular veins which travelled separately from the deep inguinal ring and joined shortly before they drain into the left renal vein. This variation may represent an immature form of complicated development of kidneys and testes. Additionally, emphasis must be put on preoperative vascular examination to avoid surgical complications from variant vessels in this region.

Comparison consequences of Jackson-Pratt drain versus chest tube after coronary artery bypass grafting: A randomized controlled clinical trial

PubMed Central

Mirmohammad-Sadeghi, Mohsen; Pourazari, Pejman; Akbari, Mojtaba

2017-01-01

Background: Chest tubes are used in every case of coronary artery bypass grafting (CABG) to evacuate shed blood from around the heart and lungs. This study was designed to assess the effective of Jackson-Pratt drain in compare with conventional chest drains after CABG. Materials and Methods: This was a randomized controlled trial that conducted on 218 patients in Chamran hospital from February to December 2016. Eligible patients were randomized in a 1:1 ratio. Jackson-Pratt drain group had 109 patients who received a chest tube insertion in the pleural space of the left lung and a Jackson-Pratt drain in mediastinum, and Chest tube drainage group had 109 patients who received double chest tube insertion in the pleural space of the left lung and the mediastinum. Results: The incidence of pleural effusions in Jackson-Pratt drain group and chest tube group were not statistically different. The pain score at 2-h in Drain group was significantly higher than chest tube group (P = 0.001), but the trend of pain score between groups was not significantly different (P = 0.097). The frequency of tamponade and atrial fibrillation (AF) were significantly lower in Jackson-Pratt drain group (P < 0.05). Conclusion: The Jackson-Pratt drain is equally effective for preventing cardiac tamponade, pleural effusions, and pain intensity in patients after CABG when compared with conventional chest tubes, but was significantly superior regarding efficacy to hospital and Intensive Care Unit length of stay and the incidence of AF. PMID:29387121

Impact of Drain Insertion After Perforated Peptic Ulcer Repair in a Japanese Nationwide Database Analysis.

PubMed

Okumura, K; Hida, K; Kunisawa, S; Nishigori, T; Hosogi, H; Sakai, Y; Imanaka, Y

2018-03-01

Many perforated peptic ulcers (PPUs) require surgical repair due to diffuse peritonitis. However, few studies have examined the clinical effects of postoperative drainage after PPU repair. This study aimed to investigate the drain insertion rates in patients who underwent PPU repair in Japan, and to clarify the impact of drain insertion on the postoperative clinical course. A retrospective nationwide cohort study was performed using administrative claims data of patients who had undergone PPU repair between 2010 and 2016. These patients were divided into two groups based on whether or not they had received a postoperative abdominal drain. Using propensity score matching, we compared the incidences of postoperative interventions for abdominal complications between both groups. A total of 4869 patients from 324 hospitals were analyzed. At the hospital level, drains were placed in all PPU repair patients in 229 (70.7%) hospitals. At the patient level, 4401 patients (90.4%) had drains inserted. The drain group was associated with a higher emergency admission rate, poorer preoperative shock status, longer anesthetic time, and a higher amount of intra-abdominal irrigation. In the propensity score-matched patients, the drain group had a significantly lower incidence of postoperative interventions than the no-drain group (1.9 vs. 5.6%; risk ratio = 0.35; 95% confidence interval 0.16-0.73; P = 0.003). Postoperative drainage was performed in the majority of patients who underwent PPU repair in Japan. Drainage following PPU repair may facilitate patient recovery by reducing the need for postoperative interventions.

Using Smoke Injection in Drains to Identify Potential Preferential Pathways in a Drained Arable Field

NASA Astrophysics Data System (ADS)

Nielsen, M. H.; Petersen, C. T.; Hansen, S.

2014-12-01

Macropores forming a continuous pathway between the soil surface and subsurface drains favour the transport of many contaminants from agricultural fields to surface waters. The smoke injection method presented by Shipitalo and Gibbs (2000) used for demonstrating and quantifying such pathways has been further developed and used on a drained Danish sandy loam. In order to identify the preferential pathways to drains, smoke was injected in three 1.15 m deep tile drains (total drain length 93 m), and smoke emitting macropores (SEMP) at the soil surface were counted and characterized as producing either strong or weak plumes compared to reference plumes from 3 and 6 mm wide tubes. In the two situations investigated in the present study - an early spring and an autumn situation, smoke only penetrated the soil surface layer via earthworm burrows located in a 1.0 m wide belt directly above the drain lines. However, it is known from previous studies that desiccation fractures in a dry summer situation also can contribute to the smoke pattern. The distance between SEMP measured along the drain lines was on average 0.46 m whereas the average spacing between SEMP with strong plumes was 2.3 m. Ponded water was applied in 6 cm wide rings placed above 52 burrows including 17 reference burrows which did not emit smoke. Thirteen pathways in the soil were examined using dye tracer and profile excavation. SEMP with strong plumes marked the entrance of highly efficient transport pathways conducting surface applied water and dye tracer into the drain. However, no single burrow was traced all the way from the surface into the drain, the dye patterns branched off in a network of other macropores. Water infiltration rates were significantly higher (P < 0.05) in SEMP with strong plumes (average rate: 247 mL min-1 n = 19) compared to SEMP with weak plumes (average rate: 87 mL min-1 n = 16) and no plumes (average rate: 56 mL min-1 n = 17). The results suggest that the smoke injection method is useful for identification of potentially efficient pathways for surface applied contaminants to drains and surface waters, pathways being associated primarily with unevenly distributed SEMP producing strong smoke plumes.

A theoretical approach to study the optical sensitivity of a MESFET

NASA Astrophysics Data System (ADS)

Dutta, Sutanu

2018-05-01

A theoretical model to study the optical sensitivity of a metal-semiconductor field effect transistor has been proposed for a relatively high drain field. An analytical expression of drain current of the device has been derived for a MESFET under optical illumination considering field dependent mobility of electrons across the channel. The variation of drain current with and without optical illumination has been studied with drain and gate voltages. The optical sensitivity of the drain current has been studied for different biasing conditions and gate lengths. In addition, the shift in threshold voltage of a MESFET under optical illumination is determined and optical sensitivity of the device in terms of its threshold voltage has been studied.

Enhancement of capacitance benefit by drain offset structure in tunnel field-effect transistor circuit speed associated with tunneling probability increase

NASA Astrophysics Data System (ADS)

Asai, Hidehiro; Mori, Takahiro; Matsukawa, Takashi; Hattori, Junichi; Endo, Kazuhiko; Fukuda, Koichi

2018-04-01

The effect of a drain offset structure on the operation speed of a tunnel field-effect transistor (TFET) ring oscillator is investigated by technology computer-aided design (TCAD) simulation. We demonstrate that the reduction of gate-drain capacitance by the drain offset structure dramatically increases the operation speed of the ring oscillators. Interestingly, we find that this capacitance benefit to operation speed is enhanced by the increase in band-to-band tunneling probability. The “synergistic” speed enhancement by the drain offset structure and the tunneling rate increase will have promising application to the significant improvement of the operation speed of TFET circuits.

Modeling the risk of water pollution by pesticides from imbalanced data.

PubMed

Trajanov, Aneta; Kuzmanovski, Vladimir; Real, Benoit; Perreau, Jonathan Marks; Džeroski, Sašo; Debeljak, Marko

2018-04-30

The pollution of ground and surface waters with pesticides is a serious ecological issue that requires adequate treatment. Most of the existing water pollution models are mechanistic mathematical models. While they have made a significant contribution to understanding the transfer processes, they face the problem of validation because of their complexity, the user subjectivity in their parameterization, and the lack of empirical data for validation. In addition, the data describing water pollution with pesticides are, in most cases, very imbalanced. This is due to strict regulations for pesticide applications, which lead to only a few pollution events. In this study, we propose the use of data mining to build models for assessing the risk of water pollution by pesticides in field-drained outflow water. Unlike the mechanistic models, the models generated by data mining are based on easily obtainable empirical data, while the parameterization of the models is not influenced by the subjectivity of ecological modelers. We used empirical data from field trials at the La Jaillière experimental site in France and applied the random forests algorithm to build predictive models that predict "risky" and "not-risky" pesticide application events. To address the problems of the imbalanced classes in the data, cost-sensitive learning and different measures of predictive performance were used. Despite the high imbalance between risky and not-risky application events, we managed to build predictive models that make reliable predictions. The proposed modeling approach can be easily applied to other ecological modeling problems where we encounter empirical data with highly imbalanced classes.

Remote sensing investigations at a hazardous-waste landfill

USGS Publications Warehouse

Stohr, C.; Su, W.-J.; DuMontelle, P.B.; Griffin, R.A.

1987-01-01

In 1976 state licensed landfilling of industrial chemicals was begun above an abandoned, underground coal mine in Illinois. Five years later organic chemical pollutants were discovered in a monitoring well, suggesting migration 100 to 1000 times faster than predicted by laboratory tests. Remote sensing contributed to the determination of the causes of faster-than-predicted pollutant migration at the hazardous-waste landfill. Aerial and satellite imagery were employed to supplement field studies of local surface and groundwater hydrology, and to chronicle site history. Drainage impediments and depressions in the trench covers collected runoff, allowing rapid recharge of surface waters to some burial trenches. These features can be more effectively identified by photointerpretation than by conventional field reconnaissance. A ground-based, post-sunset survey of the trench covers that showed that a distinction between depressions which hold moisture at the surface from freely-draining depressions which permit rapid recharge to the burial trenches could be made using thermal infrared imagery.In 1976 state licensed landfilling of industrial chemicals was begun above an abandoned, underground coal mine in Illinois. Five years later organic chemical pollutants were discovered in a monitoring well, suggesting migration 100 to 1000 times faster than predicted by laboratory tests. Remote sensing contributed to the determination of the causes of faster-than-predicted pollutant migration at the hazardous-waste landfill. Aerial and satellite imagery were employed to supplement field studies of local surface and groundwater hydrology, and to chronicle site history. Drainage impediments and depressions in the trench covers collected runoff, allowing rapid recharge of surface waters to some burial trenches.

The Regulation of CH4 and N2O fluxes by Wetlands at Landscape Level

NASA Astrophysics Data System (ADS)

Soosaar, K.; Maddison, M.; Salm, J. O.; Järveoja, J.; Hansen, R.; Mander, Ü.

2012-04-01

The world's wetlands, despite being only about 5% of the terrestrial landscape, are currently significant net sinks of more than 1 Pg yr-1 of carbon (Mitsch et al 2012). At landscape level wetlands and riparian zones are important regulators of nutrient transport (Zedler 2003). However, they can be also significant hot spots of greenhouse gas (GHG) emissions (Teiter&Mander 2005). Swedish experience shows that the nationally planned wetland creation (12,000 ha) could make a significant contribution to the targeted reduction of N fluxes (up to 27% of the Swedish environmental objective), at an environmental risk equalling 0.04% of the national anthropogenic GHG emission (Thiere et al 2011). Only few studies consider the potential GHG emission throughout both natural and created wetlands. The main objective of this study was to clarify the potential of various wetland ecosystem and riparian zones of northern rural landscapes in regulation of GHG emissions. Monthly-based measurements of GHG emissions using closed chamber method were performed from October 2007 to October 2011 in 47 study sites in Estonia. The study sites cover various wetlands and riparian forests as well as reference areas on automorphic soils. In general, wetlands' drainage was the most significant disturbance factor influencing GHG fluxes, causing significant increase of N2O emission as well as decreasing CH4 emission. However, we also observed significantly high CH4 flux from drained peatlands. In most of the soils with ground/soil water levels deeper than 30 cm from the surface, a significant decrease of CH4 fluxes were detected. The highest CH4 emissions (up to 5060 kg CH4-C ha-1 yr-1) were detected from drained fen grasslands. In the case of N2O, no clear differences were found between colder and warmer periods. Relatively higher N2O fluxes were measured from the drained fen grassland, the fertilized arable land, the riparian forest on automorphic soil, and the drained transition fen forest: median values 4.2, 1.4, 1.1, and 0.9 kg N2O-N ha-1 y-1, respectively. In peatlands, median values of CH4-C were 85.2, 23.7, 0.07 and 0.12 kg ha-1 yr-1, and N2O-N -0.05, -0.01, 0.18 and 0.19 kg ha-1 yr-1, respectively. There were significantly higher emissions of N2O from abandoned and active peat mining areas, whereas CH4 emissions were significantly higher in natural and drained areas. We also found that the buffering capacity of long-term loaded riparian alder forests in agricultural landscapes will decrease over time, which calls for the careful management of these riparian forests. Mitsch, W.J, Zhang, L., Stefanik, K.C., Nahlik, A.M., Anderson, C.J., Bernal, B., Hernandez, M., Song, K. 2012. Creating wetlands: Primary succession, water quality changes, and self-design over 15 years. BioScience in press Zedler, JB. 2003. Wetlands at your service: reducing impacts of agriculture at the watershed scale. Front. Ecol. Environ., 1, pp. 65-72 Teiter, S., Mander, U. 2005. Emission of N2O, N2, CH4, and CO2 from constructed wetlands for wastewater treatment and from riparian buffer zones. Ecol. Eng., 25, pp. 528-541 Thiere, G., Stadmark, J., Weisner, SEB. 2011. Nitrogen retention versus methane emission: Environmental benefits and risks of large-scale wetland creation. Ecol. Eng., 37, pp. 6-15

Homogenization of one-dimensional draining through heterogeneous porous media including higher-order approximations

NASA Astrophysics Data System (ADS)

Anderson, Daniel M.; McLaughlin, Richard M.; Miller, Cass T.

2018-02-01

We examine a mathematical model of one-dimensional draining of a fluid through a periodically-layered porous medium. A porous medium, initially saturated with a fluid of a high density is assumed to drain out the bottom of the porous medium with a second lighter fluid replacing the draining fluid. We assume that the draining layer is sufficiently dense that the dynamics of the lighter fluid can be neglected with respect to the dynamics of the heavier draining fluid and that the height of the draining fluid, represented as a free boundary in the model, evolves in time. In this context, we neglect interfacial tension effects at the boundary between the two fluids. We show that this problem admits an exact solution. Our primary objective is to develop a homogenization theory in which we find not only leading-order, or effective, trends but also capture higher-order corrections to these effective draining rates. The approximate solution obtained by this homogenization theory is compared to the exact solution for two cases: (1) the permeability of the porous medium varies smoothly but rapidly and (2) the permeability varies as a piecewise constant function representing discrete layers of alternating high/low permeability. In both cases we are able to show that the corrections in the homogenization theory accurately predict the position of the free boundary moving through the porous medium.

Effects of pond draining on biodiversity and water quality of farm ponds.

PubMed

Usio, Nisikawa; Imada, Miho; Nakagawa, Megumi; Akasaka, Munemitsu; Takamura, Noriko

2013-12-01

Farm ponds have high conservation value because they contribute significantly to regional biodiversity and ecosystem services. In Japan pond draining is a traditional management method that is widely believed to improve water quality and eradicate invasive fish. In addition, fishing by means of pond draining has significant cultural value for local people, serving as a social event. However, there is a widespread belief that pond draining reduces freshwater biodiversity through the extirpation of aquatic animals, but scientific evaluation of the effectiveness of pond draining is lacking. We conducted a large-scale field study to evaluate the effects of pond draining on invasive animal control, water quality, and aquatic biodiversity relative to different pond-management practices, pond physicochemistry, and surrounding land use. The results of boosted regression-tree models and analyses of similarity showed that pond draining had little effect on invasive fish control, water quality, or aquatic biodiversity. Draining even facilitated the colonization of farm ponds by invasive red swamp crayfish (Procambarus clarkii), which in turn may have detrimental effects on the biodiversity and water quality of farm ponds. Our results highlight the need for reconsidering current pond management and developing management plans with respect to multifunctionality of such ponds. Efectos del Drenado de Estanques sobre la Biodiversidad y la Calidad del Agua en Estanques de Cultivo. © 2013 Society for Conservation Biology.

Drain Current Modulation of a Single Drain MOSFET by Lorentz Force for Magnetic Sensing Application.

PubMed

Chatterjee, Prasenjit; Chow, Hwang-Cherng; Feng, Wu-Shiung

2016-08-30

This paper reports a detailed analysis of the drain current modulation of a single-drain normal-gate n channel metal-oxide semiconductor field effect transistor (n-MOSFET) under an on-chip magnetic field. A single-drain n-MOSFET has been fabricated and placed in the center of a square-shaped metal loop which generates the on-chip magnetic field. The proposed device designed is much smaller in size with respect to the metal loop, which ensures that the generated magnetic field is approximately uniform. The change of drain current and change of bulk current per micron device width has been measured. The result shows that the difference drain current is about 145 µA for the maximum applied magnetic field. Such changes occur from the applied Lorentz force to push out the carriers from the channel. Based on the drain current difference, the change in effective mobility has been detected up to 4.227%. Furthermore, a detailed investigation reveals that the device behavior is quite different in subthreshold and saturation region. A change of 50.24 µA bulk current has also been measured. Finally, the device has been verified for use as a magnetic sensor with sensitivity 4.084% (29.6 T(-1)), which is very effective as compared to other previously reported works for a single device.

Mechanisms of surface runoff genesis on a subsurface drained soil affected by surface crusting: A field investigation

NASA Astrophysics Data System (ADS)

Augeard, Bénédicte; Kao, Cyril; Chaumont, Cédric; Vauclin, Michel

Artificial drainage has been subject to widespread criticism because of its impact on water quality and because there is suspicion that it may have detrimental effects on flood genesis. The present work aims at a better understanding of the mechanisms controlling infiltration and surface runoff genesis, particularly in soils with artificial drainage and affected by surface crusting. A field experiment was conducted during one drainage season (November 2003-March 2004) in the Brie region (80 km east of Paris, France) on a subsurface drained silty soil. Water table elevation and surface runoff were monitored above the drain and at midpoint between drains. Soil water pressure head was measured at various depths and locations between the midpoint and the drain. Soil surface characteristics (microtopography and degree of structural and sedimentary crust development) were recorded regularly on the experimental site and on other plots of various drainage intensities. The results show that the first surface runoff events were induced by high water table. However, runoff was higher at midpoint between the drains because water table reached the soil surface at that point, thus considerably reducing infiltration capacity compared to that above the drain. Comparing different plots, the area with older drainage installation (1948) yielded the most surface runoff. Wider drain spacing, smaller drain depth and possible plugging may have led to a greater area of saturated soil between drains. During the winter period, the impact of raindrops induced the formation of a structural crust on the soil surface. Furthermore, the development of the sedimentary crust, which was favored by water actually flowing on the soil surface during the high water table periods could be correlated with surface runoff volume. The formation of this crust had a significant impact on runoff occurrence at the end of the winter. Therefore, poorly drained fields presented more favorable conditions for both Horton type runoff and saturation excess runoff. Drainage effectively reduces surface runoff occurrences not only by lowering the water table in winter but also by limiting soil surface sealing.

Experimental utilization of tire shreds to enhance highway drainage.

DOT National Transportation Integrated Search

2001-03-01

This project investigates the practical benefits of using shredded tires as a free draining material : in a subsurface French drain to enhance drainage along a section of highway. French drains are : below-grade structures designed to re-direct groun...

Reduction in wick drain effectiveness with spacing for Utah silts and clays.

DOT National Transportation Integrated Search

2012-04-01

Although decreasing the spacing of vertical drains usually decreases the time for consolidation, previous field tests have shown that there is a critical drain spacing for which tighter spacing does not decrease the time for consolidation. This...

Generation of airborne listeria from floor drain

USDA-ARS?s Scientific Manuscript database

Listeria monocytogenes can colonize in floor drains in poultry processing plants and further throughout processing facilities, remaining present even after cleaning and disinfection of the plant. Therefore, during wash down, workers exercise caution to prevent escape and transfer of drain microflor...

Efficacy of tranexamic acid plus drain-clamping to reduce blood loss in total knee arthroplasty: A meta-analysis.

PubMed

Zhang, Yan; Zhang, Jun-Wei; Wang, Bao-Hua

2017-06-01

Perioperative blood loss is still an unsolved problem in total knee arthroplasty (TKA). The efficacy of the preoperative use of tranexamic acid (TXA) plus drain-clamping to reduce blood loss in TKA has been debated. This meta-analysis aimed to illustrate the efficacy of TXA plus drain-clamping to reduce blood loss in patients who underwent a TKA. In February 2017, a systematic computer-based search was conducted in PubMed, EMBASE, Web of Science, the Cochrane Database of Systematic Reviews, and Google Scholar. Data from patients prepared for TKA in studies that compared TXA plus drain-clamping versus TXA alone, drain-clamping alone, or controls were retrieved. The primary endpoint was the need for transfusion. The secondary outcomes were total blood loss, blood loss in drainage, the decrease in hemoglobin, and the occurrence of deep venous thrombosis. After testing for publication bias and heterogeneity between studies, data were aggregated for random-effects models when necessary. Ultimately, 5 clinical studies with 618 patients (TXA plus drain-clamping group = 249, control group = 130, TXA-alone group = 60, and drain-clamping group = 179) were included. TXA plus drain-clamping could decrease the need for transfusion, total blood loss, blood loss in drainage, and the decrease in hemoglobin than could the control group, the TXA-alone group, and the drain-clamping group (P < .05). There was no significant difference between the occurrence of deep venous thrombosis between the included groups (P > .05). TXA plus drain-clamping can achieve the maximum effects of hemostasis in patients prepared for primary TKA. Because the number and the quality of the included studies were limited, more high-quality randomized controlled trials are needed to identify the optimal dose of TXA and the clamping hours in patients prepared for TKA.

Nitrate and phosphorus transport through subsurface drains under free and controlled drainage.

PubMed

Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

2018-05-28

Controlled drainage (CD) is a structural conservation practice in which the drainage outlet is managed in order to reduce drain flow volume and nutrient loads to water bodies. The goal of this study was to evaluate the potential of CD to improve water quality for two different seasons and levels of outlet control, using ten years of data collected from an agricultural drained field in eastern Indiana with two sets of paired plots. The Rank Sum test was used to quantify the impact of CD on cumulative annual drain flow and nitrate-N and phosphorus loads. CD plots had a statistically significant (at 5% level) lower annual drain flow (eastern pair: 39%; western pair: 25%) and nitrate load (eastern pair: 43%; western pair: 26%) compared to free draining (FD) plots, while annual soluble reactive phosphorus (SRP) and total phosphorus (TP) loads were not significantly different. An ANCOVA model was used to evaluate the impact of CD on daily drain flow, nitrate-N, SRP and TP concentrations and loads during the two different periods of control. The average percent reduction of daily drain flow was 68% in the eastern pair and 58% in the western pair during controlled drainage at the higher outlet level (winter) and 64% and 58% at the lower outlet level (summer) in the eastern and western pairs, respectively. Nitrate load reduction was similar to drain flow reduction, while the effect of CD on SRP and TP loads was not significant except for the increase in SRP in one pair. These results from a decade-long field monitoring and two different statistical methods enhance our knowledge about water quality impacts of CD system and support this management practice as a reliable system for reducing nitrate loss through subsurface drains, mainly caused by flow reduction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Efficacy of tranexamic acid plus drain-clamping to reduce blood loss in total knee arthroplasty

PubMed Central

Zhang, Yan; Zhang, Jun-Wei; Wang, Bao-Hua

2017-01-01

Abstract Background: Perioperative blood loss is still an unsolved problem in total knee arthroplasty (TKA). The efficacy of the preoperative use of tranexamic acid (TXA) plus drain-clamping to reduce blood loss in TKA has been debated. This meta-analysis aimed to illustrate the efficacy of TXA plus drain-clamping to reduce blood loss in patients who underwent a TKA. Methods: In February 2017, a systematic computer-based search was conducted in PubMed, EMBASE, Web of Science, the Cochrane Database of Systematic Reviews, and Google Scholar. Data from patients prepared for TKA in studies that compared TXA plus drain-clamping versus TXA alone, drain-clamping alone, or controls were retrieved. The primary endpoint was the need for transfusion. The secondary outcomes were total blood loss, blood loss in drainage, the decrease in hemoglobin, and the occurrence of deep venous thrombosis. After testing for publication bias and heterogeneity between studies, data were aggregated for random-effects models when necessary. Results: Ultimately, 5 clinical studies with 618 patients (TXA plus drain-clamping group = 249, control group = 130, TXA-alone group = 60, and drain-clamping group = 179) were included. TXA plus drain-clamping could decrease the need for transfusion, total blood loss, blood loss in drainage, and the decrease in hemoglobin than could the control group, the TXA-alone group, and the drain-clamping group (P < .05). There was no significant difference between the occurrence of deep venous thrombosis between the included groups (P > .05). Conclusions: TXA plus drain-clamping can achieve the maximum effects of hemostasis in patients prepared for primary TKA. Because the number and the quality of the included studies were limited, more high-quality randomized controlled trials are needed to identify the optimal dose of TXA and the clamping hours in patients prepared for TKA. PMID:28658157

Drain placement can safely be omitted for open partial nephrectomy: Results from a prospective randomized trial.

PubMed

Kriegmair, Maximilian C; Mandel, Philipp; Krombach, Patrick; Dönmez, Hasan; John, Axel; Häcker, Axel; Michel, Maurice S

2016-05-01

To examine the benefit of drain placement during open partial nephrectomy. Overall, 106 patients treated with open partial nephrectomy were enrolled in a prospective randomized trial. Based on the randomization, a drain was placed or omitted. Complications were assessed according to the Clavien classification. Pain level and requirement for analgesics was evaluated according to a customized pattern. There was no significant difference in the two groups regarding age, body mass index, American Society of Anesthesiologists score, tumor size and nephrometry (preoperative aspects and dimensions used for an anatomical classification). In terms of overall and drain-related complications, no advantage of placing a drain could be proven (P = 0.249). Patients with a drain suffered from a significantly higher pain level (P = 0.01) and showed prolonged mobilization (P < 0.001). There was no difference in bowel movements and requirement of additional analgesics (P = 0.347 and 0.11). The results of the study suggest that drain placement during open partial nephrectomy can safely be omitted, even in cases with violation of the collecting system. © 2016 The Japanese Urological Association.

Minimally invasive retrieval of a retained Jackson--Pratt drainage tube using the Sachse urethrotome.

PubMed

Fariña-Perez, Luis Angel; Pesqueira-Santiago, Daniel

2012-05-01

A retained postoperative drain tube, trapped by one or more of the sutures of the abdominal wall closure, is a rare complication of frustrating consequences and potential legal repercussions. There are few reports of techniques for minimally invasive removal of an anchored postoperative drain tube, which not infrequently has been treated by reopening the wound. A 75 years-old man with a left T2-T3N0M0 renal carcinoma was treated with transperitoneal laparoscopic nephrectomy and a Jackson-Pratt drain was left in place. Drain removal the day after revealed impossible, as if being caught with fascial suture. With the patient under sedation, we introduced a Sachse urethrotome parallel to the drain, and the abdominal fascia was identified, then the polyglycolic stitch anchoring it to the wall could be severed, freeing the drain. Percutaneous extraction with the Sachse urethrotome of an anchored postoperative drain, should be the first option, before trying a forced traction or using more complex options. This technique is for the first time published in the Spanish bibliography, and we think this possibility should be disclosed to abdominal surgeons.

A novel gate and drain engineered charge plasma tunnel field-effect transistor for low sub-threshold swing and ambipolar nature

NASA Astrophysics Data System (ADS)

Yadav, Dharmendra Singh; Raad, Bhagwan Ram; Sharma, Dheeraj

2016-12-01

In this paper, we focus on the improvement of figures of merit for charge plasma based tunnel field-effect transistor (TFET) in terms of ON-state current, threshold voltage, sub-threshold swing, ambipolar nature, and gate to drain capacitance which provides better channel controlling of the device with improved high frequency response at ultra-low supply voltages. Regarding this, we simultaneously employ work function engineering on the drain and gate electrode of the charge plasma TFET. The use of gate work function engineering modulates the barrier on the source/channel interface leads to improvement in the ON-state current, threshold voltage, and sub-threshold swing. Apart from this, for the first time use of work function engineering on the drain electrode increases the tunneling barrier for the flow of holes on the drain/channel interface, it results into suppression of ambipolar behavior. The lowering of gate to drain capacitance therefore enhanced high frequency parameters. Whereas, the presence of dual work functionality at the gate electrode and over the drain region improves the overall performance of the charge plasma based TFET.

33 CFR 149.145 - What are the requirements for curbs, gutters, drains, and reservoirs?

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION..., drains, and reservoirs? Each pumping platform complex must have enough curbs, gutters, drains, and... ocean according to the port's National Pollution Discharge Elimination System permit. ...

33 CFR 149.145 - What are the requirements for curbs, gutters, drains, and reservoirs?

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION..., drains, and reservoirs? Each pumping platform complex must have enough curbs, gutters, drains, and... ocean according to the port's National Pollution Discharge Elimination System permit. ...

Evaluation of trench and slotted drain maintenance and cleaning : Phase 1 : final report.

DOT National Transportation Integrated Search

2017-03-01

Trench and slotted drains are increasingly being used by ODOT to remove storm water from the roadways. These drains have to be properly cleaned and maintained to prevent vehicles from hydroplaning, eliminate flooding and avoid premature roadway failu...

Comparative Evaluation of Immediate Post-Operative Sequelae after Surgical Removal of Impacted Mandibular Third Molar with or without Tube Drain - Split-Mouth Study

PubMed Central

Bhate, Kalyani; Dolas, RS; Kumar, SN Santhosh; Waknis, Pushkar

2016-01-01

Introduction Third molar surgery is one of the most common surgical procedures performed in general dentistry. Post-operative variables such as pain, swelling and trismus are major concerns after impacted mandibular third molar surgery. Use of passive tube drain is supposed to help reduce these immediate post-operative sequelae. The current study was designed to compare the effect of tube drain on immediate post-operative sequelae following impacted mandibular third molar surgery. Aim To compare the post-operative sequelae after surgical removal of impacted mandibular third molar surgery with or without tube drain. Materials and Methods Thirty patients with bilateral impacted mandibular third molars were divided into two groups: Test (with tube drain) and control (without tube drain) group. In the test group, a tube drain was inserted through the releasing incision, and kept in place for three days. The control group was left without a tube drain. The post-operative variables like, pain, swelling, and trismus were calculated after 24 hours, 72 hours, 7 days, and 15 days in both the groups and analyzed statistically using chi-square and t-test analysis. Results The test group showed lesser swelling as compared to control group, with the swelling variable showing statistically significant difference at post-operative day 3 and 7 (p≤ 0.05) in both groups. There were no statistically significant differences in pain and trismus variables in both the groups. Conclusion The use of tube drain helps to control swelling following impacted mandibular third molar surgery. However, it does not have much effect on pain or trismus. PMID:28209003

Analysis of immune cells draining from the abdominal cavity as a novel tool to study intestinal transplant immunobiology.

PubMed

Meier, D; Cagnola, H; Ramisch, D; Rumbo, C; Chirdo, F; Docena, G; Gondolesi, G E; Rumbo, M

2010-10-01

During intestinal transplant (ITx) operation, intestinal lymphatics are not reconstituted. Consequently, trafficking immune cells drain freely into the abdominal cavity. Our aim was to evaluate whether leucocytes migrating from a transplanted intestine could be recovered from the abdominal draining fluid collected by a peritoneal drainage system in the early post-ITx period, and to determine potential applications of the assessment of draining cellular populations. The cell composition of the abdominal draining fluid was analysed during the first 11 post-ITx days. Using flow cytometry, immune cells from blood and draining fluid samples obtained the same day showed an almost complete lymphopenia in peripheral blood, whereas CD3(+) CD4(+) CD8(-) , CD3(+) CD4(-) CD8(+) and human leucocyte antigen D-related (HLA-DR)(+) CD19(+) lymphocytes were the main populations in the draining fluid. Non-complicated recipients evolved from a mixed leucocyte pattern including granulocytes, monocytes and lymphocytes to an exclusively lymphocytic pattern along the first post-ITx week. At days 1-2 post-Itx, analysis by short tandem repeats fingerprinting of CD3(+) CD8(+) sorted T cells from draining fluid indicated that 50% of cells were from graft origin, whereas by day 11 post-ITx this proportion decreased to fewer than 1%. Our results show for the first time that the abdominal drainage fluid contains mainly immune cells trafficking from the implanted intestine, providing the opportunity to sample lymphocytes draining from the grafted organ along the post-ITx period. Therefore, this analysis may provide information useful for understanding ITx immunobiology and eventually could also be of interest for clinical management. © 2010 The Authors. Clinical and Experimental Immunology © 2010 British Society for Immunology.

Analysis of immune cells draining from the abdominal cavity as a novel tool to study intestinal transplant immunobiology

PubMed Central

Meier, D; Cagnola, H; Ramisch, D; Rumbo, C; Chirdo, F; Docena, G; Gondolesi, G E; Rumbo, M

2010-01-01

During intestinal transplant (ITx) operation, intestinal lymphatics are not reconstituted. Consequently, trafficking immune cells drain freely into the abdominal cavity. Our aim was to evaluate whether leucocytes migrating from a transplanted intestine could be recovered from the abdominal draining fluid collected by a peritoneal drainage system in the early post-ITx period, and to determine potential applications of the assessment of draining cellular populations. The cell composition of the abdominal draining fluid was analysed during the first 11 post-ITx days. Using flow cytometry, immune cells from blood and draining fluid samples obtained the same day showed an almost complete lymphopenia in peripheral blood, whereas CD3+CD4+CD8-, CD3+CD4-CD8+ and human leucocyte antigen D-related (HLA-DR)+CD19+ lymphocytes were the main populations in the draining fluid. Non-complicated recipients evolved from a mixed leucocyte pattern including granulocytes, monocytes and lymphocytes to an exclusively lymphocytic pattern along the first post-ITx week. At days 1–2 post-Itx, analysis by short tandem repeats fingerprinting of CD3+CD8+ sorted T cells from draining fluid indicated that 50% of cells were from graft origin, whereas by day 11 post-ITx this proportion decreased to fewer than 1%. Our results show for the first time that the abdominal drainage fluid contains mainly immune cells trafficking from the implanted intestine, providing the opportunity to sample lymphocytes draining from the grafted organ along the post-ITx period. Therefore, this analysis may provide information useful for understanding ITx immunobiology and eventually could also be of interest for clinical management. PMID:20831713

Concentrations and loads of suspended sediment and nutrients in surface water of the Yakima River basin, Washington, 1999-2000 [electronic resource] : with an analysis of trends in concentrations

USGS Publications Warehouse

Ebbert, James C.; Embrey, Sandra S.; Kelley, Janet A.

2003-01-01

Spatial and temporal variations in concentrations and loads of suspended sediment and nutrients in surface water of the Yakima River Basin were assessed using data collected during 1999?2000 as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program. Samples were collected at 34 sites located throughout the Basin in August 1999 using a Lagrangian sampling design, and also were collected weekly and monthly from May 1999 through January 2000 at three of the sites. Nutrient and sediment data collected at various time intervals from 1973 through 2001 by the USGS, Bureau of Reclamation, Washington State Department of Ecology, and Roza-Sunnyside Board of Joint Control were used to assess trends in concentrations. During irrigation season (mid-March to mid-October), concentrations of suspended sediment and nutrients in the Yakima River increase as relatively pristine water from the forested headwaters moves downstream and mixes with discharges from streams, agricultural drains, and wastewater treatment plants. Concentrations of nutrients also depend partly on the proportions of mixing between river water and discharges: in years of ample water supply in headwater reservoirs, more water is released during irrigation season and there is more dilution of nutrients discharged to the river downstream. For example, streamflow from river mile (RM) 103.7 to RM 72 in August 1999 exceeded streamflow in July 1988 by a factor of almost 2.5, but loads of total nitrogen and phosphorus discharged to the reach from streams, drains, and wastewater treatment plants were only 1.2 and 1.1 times larger. In years of ample water supply, canal water, which is diverted from either the Yakima or Naches River, makes up more of the flow in drains and streams carrying agricultural return flows. The canal water dilutes nutrients (especially nitrate) transported to the drains and streams in runoff from fields and in discharges from subsurface field drains and the shallow ground-water system. The average concentration of total nitrogen in drains and streams discharging to the Yakima River from RM 103.7 to RM 72 in August 1999 was 2.63 mg/L, and in July 1988 was 3.16 mg/L; average concentrations of total phosphorus were 0.20 and 0.26 mg/L. After irrigation season, streamflow in agricultural drains decreases because irrigation water is no longer diverted from the Yakima and Naches Rivers. As a result, concentrations of total nitrogen in drains increase because nitrate, which constitutes much of total nitrogen, continues to enter the drains from subsurface drains and shallow ground water. Concentrations of total phosphorus and suspended sediment often decrease, because they are transported to the drains in runoff of irrigation water from fields. In Granger Drain, concentrations of total nitrogen ranged from 2-4 mg/L during irrigation season and increased to about 6 mg/L after irrigation season, and concentrations of total phosphorus, as high as 1 mg/L, decreased to about 0.2 mg/L. In calendar year 1999, Moxee Drain transported an average of 28,000 lb/d (pounds per day) of suspended sediment, 380 lb/d of total nitrogen, and 46 lb/d of total phosphorus to the Yakima River. These loads were about half the average loads transported by Granger Drain during the same period. Average streamflows were similar for the two drains, so the difference in loads was due to differences in constituent concentrations: those in Moxee Drain were about 40-60 percent less than those in Granger Drain. Loads of suspended sediment and total phosphorus in Moxee and Granger Drains were nearly four times higher during irrigation season than during the non-irrigation season because with increased flow during irrigation season, concentrations of suspended sediment and total phosphorus are usually higher. Loads of nitrate in the drains were about the same in both seasons because nitrate concentrations are higher during the non-irrigation season.

Towards evidence-based emergency medicine: best BETs from the Manchester Royal Infirmary. BET 4: does size matter? Chest drains in haemothorax following trauma.

PubMed

2013-11-01

A short-cut review was carried out to establish whether the size of chest drain inserted is important in haemothoraces. Forty-nine papers were found of which four presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are shown in table 4. The clinical bottom line is that while the available evidence suggests that small bore drains may be as effective as large bore drains in resolving traumatic haemothoraces without additional complications, there is insufficient evidence currently available to recommend a change to standard practice (ie, large bore drains).

Effects of drain bias on the statistical variation of double-gate tunnel field-effect transistors

NASA Astrophysics Data System (ADS)

Choi, Woo Young

2017-04-01

The effects of drain bias on the statistical variation of double-gate (DG) tunnel field-effect transistors (TFETs) are discussed in comparison with DG metal-oxide-semiconductor FETs (MOSFETs). Statistical variation corresponds to the variation of threshold voltage (V th), subthreshold swing (SS), and drain-induced barrier thinning (DIBT). The unique statistical variation characteristics of DG TFETs and DG MOSFETs with the variation of drain bias are analyzed by using full three-dimensional technology computer-aided design (TCAD) simulation in terms of the three dominant variation sources: line-edge roughness (LER), random dopant fluctuation (RDF) and workfunction variation (WFV). It is observed than DG TFETs suffer from less severe statistical variation as drain voltage increases unlike DG MOSFETs.

Metals transport in the Sacramento River, California, 1996-1997; Volume 1, Methods and data

USGS Publications Warehouse

Alpers, Charles N.; Taylor, Howard E.; Domagalski, Joseph L.

2000-01-01

Metals transport in the Sacramento River, northern California, was evaluated on the basis of samples of water, suspended colloids, streambed sediment, and caddisfly larvae that were collected on one to six occasions at 19 sites in the Sacramento River Basin from July 1996 to June 1997. Four of the sampling periods (July, September, and November 1996; and May-June 1997) took place during relatively low-flow conditions and two sampling periods (December 1996 and January 1997) took place during high-flow and flooding conditions; respectively. Tangential-flow ultrafiltration with 10,000 nominal molecular weight limit, or daltons (0.005 micrometer equivalent), pore-size membranes was used to separate metals in streamwater into ultrafiltrate (operationally defined dissolved fraction) and retentate (colloidal fraction) components, respectively. Conventional filtration with capsule filters (0.45 micrometer pore-size) and membrane filters (0.40 micrometer pore-size) and total-recoverable analysis of unfiltered (whole-body) samples were done for comparison at all sites. Because the total-recoverable analysis involves an incomplete digestion of particulate matter, a more reliable measurement of whole-water concentrations is derived from the sum of the dissolved component that is based on the ultrafiltrate plus the suspended component that is based on a total digestion of colloid concentrates from the ultra-filtration retentate. Metals in caddisfly larvae were determined for whole-body samples and cytosol extracts, which are intercellular solutions that provide a more sensitive indication of the metals that have been bioaccumulated. Trace metals in acidic, metal-rich drainage from abandoned and inactive sulfide mines were observed to enter the Sacramento River system (specifically, into both Shasta Lake and Keswick Reservoir) in predominantly dissolved form, as operationally defined using ultrafiltrates. The predominant source of acid mine drainage to Keswick Reservoir is Spring Creek, which drains the Iron Mountain mine area. Copper concentrations in filtered samples from Spring Creek taken during December 1996, January 1997, and May 1997 ranged from 420 to 560 micrograms per liter. Below Keswick Dam, copper concentrations in conventionally filtered samples ranged from 0.5 micrograms per liter during September 1996 to 9.4 micrograms per liter during January 1997; the latter concentration exceeded the applicable water-quality standard. The proportion of trace metals that was dissolved (versus colloidal) in samples collected at Shasta and Keswick dams decreased in the order cadmium zinc > copper > aluminum iron lead mercury. At four sampling sites on the Sacramento River at various distances downstream of Keswick Dam (Bend Bridge, 71 kilometers; Colusa, 256 kilometers; Verona, 360 kilometers; and Freeport, 412 kilometers) concentrations of these seven metals were predominantly colloidal during both high- and low-flow conditions. Because copper compounds are used extensively as algaecides in rice farming, agricultural drainage at the Colusa Basin Drain was sampled in June 1997 during a period shortly after copper applications to newly planted rice fields. Copper concentrations ranged from 1.3 to 3.0 micrograms per liter in filtered samples and from 12 to 13 micrograms per liter in whole-water samples (total recoverable analysis). These results are consistent with earlier work by the U.S. Geological Survey indicating that copper in rice-field drainage likely represents a detectable, but relatively minor source of copper to the Sacramento River. Lead isotope data from suspended colloids and streambed sediments collected during October and November 1996 indicate that lead from acid mine drainage sources became a relatively minor component of the total lead at the site located 71 kilometers downstream of Keswick Dam and beyond. Cadmium, copper, and zinc concentrations in caddisfly larvae were elevated at several sites downstream of Keswick Dam,

76 FR 76060 - Final Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-06

... Port Georgetown. Sheldon Street. At the confluence with +646 Knight Intercounty Drain. Bliss Creek.... Georgetown. At the downstream side of +616 Kenowa Avenue Southwest. Knight Intercounty Drain At the... River/Black Creek of Zeeland Approximately 0.8 mile +584 Charter Township of Drain. upstream of River...

14 CFR 121.241 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Oil system drains. 121.241 Section 121.241..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.241 Oil system drains... position, must be provided to allow safe drainage of the entire oil system. ...

14 CFR 121.241 - Oil system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Oil system drains. 121.241 Section 121.241..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.241 Oil system drains... position, must be provided to allow safe drainage of the entire oil system. ...

14 CFR 121.241 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Oil system drains. 121.241 Section 121.241..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.241 Oil system drains... position, must be provided to allow safe drainage of the entire oil system. ...

Charge-Dissipative Electrical Cables

NASA Technical Reports Server (NTRS)

Kolasinski, John R.; Wollack, Edward J.

2004-01-01

Electrical cables that dissipate spurious static electric charges, in addition to performing their main functions of conducting signals, have been developed. These cables are intended for use in trapped-ion or ionizing-radiation environments, in which electric charges tend to accumulate within, and on the surfaces of, dielectric layers of cables. If the charging rate exceeds the dissipation rate, charges can accumulate in excessive amounts, giving rise to high-current discharges that can damage electronic circuitry and/or systems connected to it. The basic idea of design and operation of charge-dissipative electrical cables is to drain spurious charges to ground by use of lossy (slightly electrically conductive) dielectric layers, possibly in conjunction with drain wires and/or drain shields (see figure). In typical cases, the drain wires and/or drain shields could be electrically grounded via the connector assemblies at the ends of the cables, in any of the conventional techniques for grounding signal conductors and signal shields. In some cases, signal shields could double as drain shields.

Slit-lamp technique of draining interface fluid following Descemet's stripping endothelial keratoplasty.

PubMed

Srinivasan, Sathish; Rootman, David S

2007-09-01

To describe a new slit-lamp technique for draining interface fluid to manage complete donor disc detachments following Descemet's stripping (automated) endothelial keratoplasty (DSEK/DSAEK). Interventional case series. Five DSEK/DSAEK patients presented on the first postoperative day with complete detachment of the donor lenticule. Slit-lamp biomicroscopy showed interface fluid preventing attachment of the donor disc to the host stromal bed. A new slit-lamp technique is described to drain the interface fluid. This technique involved completely filling the anterior chamber with an air bubble using a 30-gauge needle on a 3 ml syringe. Following this, a 0.12 forceps was used to open the inferior mid-peripheral corneal drainage slit to drain the interface fluid. This technique was successful in draining the interface fluid in all five patients, leading to immediate complete reattachment of the donor disc. Donor disc detachments following DSEK/DSAEK can be successfully managed by this slit-lamp technique of draining the interface fluid.

Pupal productivity & nutrient reserves of Aedes mosquitoes breeding in sewage drains & other habitats of Kolkata, India: Implications for habitat expansion & vector management.

PubMed

Banerjee, Soumyajit; Mohan, Sushree; Saha, Nabaneeta; Mohanty, Siba Prasad; Saha, Goutam K; Aditya, Gautam

2015-12-01

The quality of breeding sites is reflected through the pupal productivity and the life history traits of Aedes mosquitoes. Using nutrient reserves and pupal productivity of Aedes as indicators, the larval habitats including sewage drains were characterized to highlight the habitat expansion and vector management. The pupae and adults collected from the containers and sewage drains were characterized in terms of biomass and nutrient reserves and the data were subjected to three way factorial ANOVA. Discriminant function analyses were performed to highlight the differences among the habitats for sustenance of Aedes mosquitoes. Survey of larval habitats from the study area revealed significant differences (P<0.05) in the pupal productivity of Aedes among the habitats and months. Despite sewage drains being comparatively less utilized for breeding, the pupae were of higher biomass with corresponding adults having longer wings in contrast to other habitats. The nutrient reserve of the adults emerging from pupae of sewage drains was significantly higher (P<0.05), compared to other habitats, as reflected through the discriminant function analysis. The present results showed that for both Ae. aegypti and Ae. albopictus, sewage drains were equally congenial habitat as were plastic, porcelain and earthen habitats. Availability of Aedes immature in sewage drains poses increased risk of dengue, and thus vector control programme should consider inclusion of sewage drains as breeding habitat of dengue vector mosquitoes.

Jet-controlled freeze valve for use in a glass melter

DOEpatents

Routt, Kenneth R.

1986-09-02

A drain valve for use in a furnace for the melting of thermoplastic material. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The flow member is adapted to fit in mating relationship in the drain cavity. A freeze valve member is disposed adjacent the outlet of the flow member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct streams of pressurized air at the outlet to control the flow of thermoplastic material through the flow members. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace. The drain valve includes a flow tube member having an inlet and outlet, and having heating and cooling means. The tube member is adapted to fit in mating relationship with the drain cavity. A freeze valve member is disposed at the outlet of the flow tube member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct a stream of pressurized air at the outlet to control the flow of glass through the flow tube member.

Comparison of natural drainage group and negative drainage groups after total thyroidectomy: prospective randomized controlled study.

PubMed

Woo, Seung Hoon; Kim, Jin Pyeong; Park, Jung Je; Shim, Hyun Seok; Lee, Sang Ha; Lee, Ho Joong; Won, Seong Jun; Son, Hee Young; Kim, Rock Bum; Son, Young-Ik

2013-01-01

The aim of this study was to compare a negative pressure drain with a natural drain in order to determine whether a negative pressure drainage tube causes an increase in the drainage volume. Sixty-two patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC) were enrolled in the study between March 2010 and August 2010 at Gyeongsang National University Hospital. The patients were prospectively and randomly assigned to two groups, a negative pressure drainage group (n=32) and natural drainage group (n=30). Every 3 hours, the volume of drainage was checked in the two groups until the tube was removed. The amount of drainage during the first 24 hours postoperatively was 41.68 ± 3.93 mL in the negative drain group and 25.3 ± 2.68 mL in the natural drain group (p<0.001). After 24 additional hours, the negative drain group was 35.19 ± 4.26 mL and natural drain groups 21.53 ± 2.90 mL (p<0.001). However, the drainage at postoperative day 3 was not statistically different between the two groups. In addition, the vocal cord palsy and temporary and permanent hypocalcemia were not different between the two groups. These results indicate that a negative pressure drain may increase the amount of drainage during the first 24-48 hours postoperatively. Therefore, it is not necessary to place a closed suction drain when only a total thyroidectomy is done.

Jet-controlled freeze valve for use in a glass melter

DOEpatents

Routt, Kenneth R.

1986-01-01

A drain valve for use in a furnace for the melting of thermoplastic material. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The flow member is adapted to fit in mating relationship in the drain cavity. A freeze valve member is disposed adjacent the outlet of the flow member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct streams of pressurized air at the outlet to control the flow of thermoplastic material through the flow members. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace. The drain valve includes a flow tube member having an inlet and outlet, and having heating and cooling means. The tube member is adapted to fit in mating relationship with the drain cavity. A freeze valve member is disposed at the outlet of the flow tube member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct a stream of pressurized air at the outlet to control the flow of glass through the flow tube member.

Evaluation of the Environmental Fate of Munition Compounds in Soil.

DTIC Science & Technology

1979-06-01

temperature in- duction furnace. Nitrate Water samples were analyzed for nitrate (NO:T) by a Dion -X System Ten ion chromatograph. Nitrite Water samples...moderately well drained Celins , somewhat poorly drained Crosby and Conover, and very poorly drained Kokomo form a drainage sequence with the

The Draining Cylinder

ERIC Educational Resources Information Center

James Graham-Eagle

2009-01-01

This article explores the time it takes for a liquid to drain from a cylindrical container through a hole in the bottom. Using dimensional analysis and some thought experiments this time is determined and Torricelli's law derived as a consequence. Finally, the effect of pouring liquid into the container as it drains is considered.

Toxic-Waste Disposal by Drain-in-Furnace Technique

NASA Technical Reports Server (NTRS)

Compton, L. E.; Stephens, J. B.; Moynihan, P. I.; Houseman, J.; Kalvinskas, J. J.

1986-01-01

Compact furnace moved from site to site. Toxic industrial waste destroyed using furnace concept developed for disposal of toxic munitions. Toxic waste drained into furnace where incinerated immediately. In furnace toxic agent rapidly drained and destroyed in small combustion chamber between upper and lower layers of hot ceramic balls

75 FR 61999 - Airworthiness Directives; The Boeing Company Model 767 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-07

..., for certain airplanes, reworking the bonding jumper assemblies on the drain tube assemblies of the... inspections of the drain tube assemblies of the slat track housing of the wings to find discrepancies... would also require replacing the drain tube assemblies. For certain airplanes, this proposed AD would...

14 CFR 27.1021 - Oil system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil system drains. 27.1021 Section 27.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS...) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible; and (b...

14 CFR 27.1021 - Oil system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil system drains. 27.1021 Section 27.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS...) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible; and (b...

Treatment of phosphorus transported from tile and ditch-drained agricultural fields using sorption materials

USDA-ARS?s Scientific Manuscript database

Many flat, poorly drained soils, such as the Delmarva Peninsula, the upper Midwest, and certain areas of Europe such as Denmark and Netherlands, have been extensively drained through the construction of artificial drainage ditches and tiles to allow agriculture and other human activities. In additi...

Theory of Maxwell's fish eye with mutually interacting sources and drains

NASA Astrophysics Data System (ADS)

Leonhardt, Ulf; Sahebdivan, Sahar

2015-11-01

Maxwell's fish eye is predicted to image with a resolution not limited by the wavelength of light. However, interactions between sources and drains may ruin the subwavelength imaging capabilities of this and similar absolute optical instruments. Nevertheless, as we show in this paper, at resonance frequencies of the device, an array of drains may resolve a single source, or alternatively, a single drain may scan an array of sources, no matter how narrowly spaced they are. It seems that near-field information can be obtained from far-field distances.

High efficiency FET microwave detector design

NASA Astrophysics Data System (ADS)

Luglio, Juan; Ishii, Thomas Koryu

1990-12-01

The work is based on an assumption that very little microwave power would be consumed at a negatively biased gate of a microwave FET, yet significant detected signals would be obtained at the drain if the bias is given. By analyzing a Taylor-series expansion of the drain-current equation in the vicinity of a fixed gate-bias voltage, the bias voltage is found to maximize the second derivative of the drain current, the gate-bias voltage characteristic curve for the maximum detected drain current under a given fixed drain-bias voltage. Based on these findings, a high-efficiency microwave detector is designed, fabricated, and tested at 8.6 GHz, and it is shown that the audio power over absorbed microwave power ratio of the detector is 135 percent due to the positive gain.

Successful Removal of Malpositioned Chest Drain Within the Liver by Embolization of the Transhepatic Track

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

Tait, Paul; Waheed, Umeer; Bell, Suzanne, E-mail: drsuzy29@hotmail.co

2009-07-15

The insertion of a chest drain catheter for the management of a pneumothorax in an 82-year-old woman resulted in the unusual complication of liver penetration. The position of the drain was assessed by contrast-enhanced computed tomographic scan. Because the patient was hemodynamically stable and no damage to major vessels was seen on computed tomographic scan, the patient was treated in a nonoperative manner. A procedure was performed under controlled conditions using techniques used during transhepatic liver biopsies but with the addition of a balloon catheter. Embolization of the liver track was performed during chest drain removal. The drain was successfullymore » removed without the complication of bleeding in a patient unsuitable for a general anesthetic.« less

How to remove a chest drain.

PubMed

Allibone, Elizabeth

2015-10-07

RATIONALE AND KEY POINTS: This article aims to help nurses to undertake the removal of a chest drain in a safe, effective and patient-centred manner. This procedure requires two practitioners. The chest drain will have been inserted aseptically to remove air, blood, fluid or pus from the pleural cavity. ▶ Chest drains may be small or wide bore depending on the underlying condition and clinical setting. They may be secured with a mattress suture and/or an anchor suture. ▶ Chest drains are usually removed under medical instructions when the patient's lung has inflated, the underlying condition has resolved, there is no evidence of respiratory compromise or failure, and their anticoagulation status has been assessed as satisfactory. ▶ Chest drains secured with a mattress suture should be removed by two practitioners. One practitioner is required to remove the tube and the other to tie the mattress suture (if present) and secure the site. REFLECTIVE ACTIVITY: Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. How reading this article will change your practice. 2. How this article could be used to educate patients with chest drains. Subscribers can upload their reflective accounts at: rcni.com/portfolio .

Autotransfusion after total knee arthroplasty. Effects on blood cells, plasma chemistry, and whole blood rheology.

PubMed

Dalén, T; Broström, L A; Engström, K G

1997-08-01

Postoperative drain blood was collected and reinfused using the ConstaVac system (Stryker, Kalamazoo, MI) in 30 patients after total knee arthroplasty. Of the total 1.1-L volume of postoperative bleeding, 60% was reinfused. No clinical complications were observed. Differences between venous blood and drain blood and between venous blood and drain blood after separate incubation were studied with respect to acidic and inflammatory effects on blood cells, plasma chemistry, and whole blood rheology. In drain blood, leukocyte and platelet counts were reduced (P < .001), probably as a result of consumption in the wound. Acidic incubation occurs in the drain container because of production of lactate from glucose, with a minimum pH at 5 hours of 7.2. The low pH caused slight but significant erythrocyte swelling (P < .01). The complement C3d indicated leukocyte activation, although of modest magnitude. Despite incubation and complement activation, maximum erythrocyte hemolysis after 24 hours of incubation was less than 1%. Drain blood showed a lower resistance against micropore filtration than venous blood (P < .001), mainly because of the reduced number of leukocytes, and remained unchanged with incubation. Although the autotransfusion system can be improved with respect to blood quality, filtered drain blood should be considered acceptable for reinfusion.

Linking selenium sources to ecosystems: San Francisco Bay-Delta Model

USGS Publications Warehouse

Presser, Theresa S.; Luoma, Samuel N.

2004-01-01

Marine sedimentary rocks of the Coast Ranges contribute selenium to soil, surface water, and ground water in the western San Joaquin Valley, California. Irrigation funnels selenium into a network of subsurface drains and canals. Proposals to build a master drain (i.e., San Luis Drain) to discharge into the San Francisco Bay-Delta Estuary remain as controversial today as they were in the 1950s, when drainage outside the San Joaquin Valley was first considered. An existing 85-mile portion of the San Luis Drain was closed in 1986 after fish mortality and deformities in ducks, grebes and coots were discovered at Kesterson National Wildlife Refuge, the temporary terminus of the drain. A 28-mile portion of the drain now conveys drainage from 100,000 acres into the San Joaquin River and eventually into the Bay-Delta. If the San Luis Drain is extended directly to the Bay-Delta, as is now being proposed as an alternative to sustain agriculture, it could receive drainage from an estimated one-million acres of farmland affected by rising water tables and increasing salinity. In addition to agricultural sources, oil refineries also discharge selenium to the Bay-Delta, although those discharges have declined in recent years. To understand the effects of changing selenium inputs, scientists have developed the Bay-Delta Selenium Model.

Developing an evidence-based nursing protocol on wound drain management for total joint arthroplasty.

PubMed

Tsang, Lap Fung

2015-05-01

Although various drains have long been used for many years in total joint replacement, there is a paucity of evidence for the benefit of drain applications. Evidence suggests inconsistent practice in the use of drainage systems, whether intermittently applying suction or free of suction in the application of drainage systems, as well as the optimal timing for wound drain removal. It aimed to perform a systematic review to develop an evidence-based nursing protocol to manage wound drainage following total joint arthroplasty. A comprehensive systematic review of available evidence up to 2013. Searches of the EMBASE, Cochrane library, CINAHL, Medline electronic databases and an internet search by Yahoo and Google engine returned 2840 records, of which 11 met the inclusion criteria for this review. A further two papers were obtained through scanning the reference lists of those articles included from the initial literature search. Different clamping times were retrieved from the literature. A protocol was adapted for clinical application according to the summary of the retrieved information. It is suggested that clamping is performed 1 h after the insertion of suction drains post-operatively in the operating theatre. Wound drains should be clamped for 1 h if blood loss is more than 600 ml in 6 h in first 24 h. Wound drains should be clamped for 1 h if blood loss is more than 800 ml in 8 h thereafter. It is suggested that the drainage reservoir bottle should be mark and findings recorded in line with the principle of drain clamping. This means that the amount of drainage is measured and recorded every 6 h in first 24 h and every 8 h thereafter. It is suggested that wound drains should be remove before 48 h after TJR. If blood loss is less than 50 ml in past 6 h or less than 70 ml in past 8 h, the drain should be remove and the wound site should be monitored closely. This paper has guided nurses to develop an evidence-based protocol to improve patient care on wound drain management. Further study is necessary to evaluate the effectiveness of the protocol. Copyright © 2014 Elsevier Ltd. All rights reserved.

Gummel Symmetry Test on charge based drain current expression using modified first-order hyperbolic velocity-field expression

NASA Astrophysics Data System (ADS)

Singh, Kirmender; Bhattacharyya, A. B.

2017-03-01

Gummel Symmetry Test (GST) has been a benchmark industry standard for MOSFET models and is considered as one of important tests by the modeling community. BSIM4 MOSFET model fails to pass GST as the drain current equation is not symmetrical because drain and source potentials are not referenced to bulk. BSIM6 MOSFET model overcomes this limitation by taking all terminal biases with reference to bulk and using proper velocity saturation (v -E) model. The drain current equation in BSIM6 is charge based and continuous in all regions of operation. It, however, adopts a complicated method to compute source and drain charges. In this work we propose to use conventional charge based method formulated by Enz for obtaining simpler analytical drain current expression that passes GST. For this purpose we adopt two steps: (i) In the first step we use a modified first-order hyperbolic v -E model with adjustable coefficients which is integrable, simple and accurate, and (ii) In the second we use a multiplying factor in the modified first-order hyperbolic v -E expression to obtain correct monotonic asymptotic behavior around the origin of lateral electric field. This factor is of empirical form, which is a function of drain voltage (vd) and source voltage (vs) . After considering both the above steps we obtain drain current expression whose accuracy is similar to that obtained from second-order hyperbolic v -E model. In modified first-order hyperbolic v -E expression if vd and vs is replaced by smoothing functions for the effective drain voltage (vdeff) and effective source voltage (vseff), it will as well take care of discontinuity between linear to saturation regions of operation. The condition of symmetry is shown to be satisfied by drain current and its higher order derivatives, as both of them are odd functions and their even order derivatives smoothly pass through the origin. In strong inversion region and technology node of 22 nm the GST is shown to pass till sixth-order derivative and for weak inversion it is shown till fifth-order derivative. In the expression of drain current major short channel phenomena like vertical field mobility reduction, velocity saturation and velocity overshoot have been taken into consideration.

Effects of Post-fire Succession and Edaphic Conditions on Tree Transpiration in a Boreal Black Spruce Forest

NASA Astrophysics Data System (ADS)

Angstmann, J. L.; Ewers, B. E.; Kwon, H.; Bond-Lamberty, B.; Amiro, B.; Gower, S. T.

2007-12-01

Boreal forest ecosystems play an integral role in global climate change because of their large land area and ability to store large quantities of carbon. Quantifying and explaining tree water use in both well- and poorly- drained soils and across successional development is critical in understanding the influence of physiological processes on carbon, water, and energy cycling. Four black spruce stands burned in 1850, 1930, 1964, and 1989 were chosen for this research because they had been shown in previous studies to represent critical stages of forest development that capture the successional impacts of both leaf area and species composition change. We hypothesized that tree transpiration will differ between well- and poorly-drained areas and with age due to 1) tree size and age and edaphic-related hydraulic adjustments and 2) tree size will be explained by species specific growth differences from edaphic conditions. Sap flux, leaf water potential (\\PsiL), site specific allometric relationships between sapwood area and leaf area and soil properties such as texture and organic matter depth in each of the four burn ages were utilized to test these hypotheses. Results show that sap flux for Picea mariana at the 1964 burn age differed between well- and poorly-drained soils when scaled per unit xylem area with trees located on poorly-drained soils experiencing higher sap flux rates than trees in well- drained areas (101.79 & 83.02 g cm-2 day-1 respectively). However, when scaled to transpiration on a per tree basis, taking tree size into account, trees on well-drained soils had higher rates than those in poorly- drained locations (366.96 & 216.82 g tree-1 day-1 respectively). The presence of Pinus banksiana and Populus tremuloides in the well-drained areas increased stand transpiration rates for these areas considerably as compared to the poorly-drained areas. Midday \\PsiL for all four burns show no significant difference between well- and poorly-drained (average midday \\PsiL = -1.23 & -1.29 MPa respectively) sites for Picea mariana (t-value = -0.591, df = 6, p-value = 0.576). This indicates that tree size, which is constrained by growth and anaerobic conditions, drives differences in tree transpiration for well- and poorly-drained soils.

Characterizing subsurface water flow to artificial drain lines using fiber-optic distributed temperature sensing

NASA Astrophysics Data System (ADS)

Shults, D.; Brooks, E. S.; Heinse, R.; Keller, C. K.

2017-12-01

Over the last several years growers have experienced increasingly wet spring conditions in the Palouse Region located in North Idaho, Eastern Washington and Eastern Oregon. As a result more artificial drain lines are being installed so growers can access their fields earlier in the growing season. Additionally there has been increasing adoption of no-tillage practices among growers in order minimize erosion and runoff in the region. There is a growing body of evidence that suggests long-term no-tillage may lead to the establishment of large macropore networks through increased earthworm activity and the preservation of root channels. These macropore networks, in conjunctions with the presence of artificial drains lines, may create connected preferential flow paths from agricultural fields to receiving streams. This connectivity of flow paths from agricultural fields to receiving water bodies may increase the loading of nutrients and agricultural chemicals as some flow paths may largely bypass soil matrix interaction where materials can be sequestered. Our primary objective for this study was to characterize subsurface flow to two artificial drain lines, one under conventional tillage and the other under no-tillage, using distributed temperature sensing (DTS) technology. During the study (November 2016-April 2017) the near surface soil-water temperature was consistently colder than that of deeper depths. Temperature was thus used as a tracer as snow melt and soil-water moved from the near surface to the drain lines during snowmelt and precipitation events. The spatial and temporal variability of the temperature along the artificial drain line under no-tillage practices was found to be greater than that of the conventional tilled field. It is hypothesized that preferential flow paths are responsible for the increased variability of temperature seen in the drain line under long term no-till management. The temperature along the conventional till drain line showed a dampened response to snow melt and precipitation events during the winter indicating matrix flow was the predominate flow mechanism. In addition to temperature traces, water chemistry (electrical conductivity, pH and nitrate) and discharge measurements were collected at the outlet of each drain line as well as at access ports along the drain lines.

Storm drains as larval development and adult resting sites for Aedes aegypti and Aedes albopictus in Salvador, Brazil.

PubMed

Paploski, Igor Adolfo Dexheimer; Rodrigues, Moreno S; Mugabe, Vánio André; Kikuti, Mariana; Tavares, Aline S; Reis, Mitermayer Galvão; Kitron, Uriel; Ribeiro, Guilherme Sousa

2016-07-27

Dengue (DENV), Chikungunya (CHIKV), Zika (ZIKV), as well as yellow fever (YFV) viruses are transmitted to humans by Aedes spp. females. In Salvador, the largest urban center in north-eastern Brazil, the four DENV types have been circulating, and more recently, CHIKV and ZIKV have also become common. We studied the role of storm drains as Aedes larval development and adult resting sites in four neighbourhoods of Salvador, representing different socioeconomic, infrastructure and topographic conditions. A sample of 122 storm drains in the four study sites were surveyed twice during a 4-month period in 2015; in 49.0 % of the visits, the storm drains contained water. Adults and immatures of Aedes aegypti were captured in two of the four sites, and adults and immatures of Aedes albopictus were captured in one of these two sites. A total of 468 specimens were collected: 148 Ae. aegypti (38 adults and 110 immatures), 79 Ae. albopictus (48 adults and 31 immatures), and 241 non-Aedes (mainly Culex spp.) mosquitoes (42 adults and 199 immatures). The presence of adults or immatures of Ae. aegypti in storm drains was independently associated with the presence of non-Aedes mosquitoes and with rainfall of ≤ 50 mm during the preceding week. We found that in Salvador, one of the epicentres of the 2015 ZIKV outbreak, storm drains often accumulate water and serve as larval development sites and adult resting areas for both Ae. aegypti and Ae. albopictus. Vector control campaigns usually overlook storm drains, as most of the effort to prevent Ae. agypti reproduction is directed towards containers in the domicile environment. While further studies are needed to determine the added contribution of storm drains for the maintenance of Aedes spp. populations, we advocate that vector control programs incorporate actions directed at storm drains, including regular inspections and use of larvicides, and that human and capital resources are mobilized to modify storm drains, so that they do not serves as larval development sites for Aedes (and other) mosquitoes.

Tracking an Unusual Carbapenemase-producing Organism from Drains to Patient Using Whole Genome Sequencing

PubMed Central

Ramsburg, Amanda M; Weingarten, Rebecca A; Conlan, Sean P; Dekker, John P; Michelin, Angela V; Odom, Robin T; Bordner, MaryAnn; Zellmer, Caroline J; Henderson, David K; Segre, Julia A; Frank, Karen M; Palmore, Tara N

2017-01-01

Abstract Background The NIH Clinical Center conducts patient and environmental surveillance for carbapenemase-producing organisms (CPO). Previous investigation revealed that sink drains can become colonized with CPO. Subsequent surveillance targets included potential aqueous reservoirs, such as floor drains of environmental services (EVS) closets. Methods Premoistened swabs were used to culture sink drains, floor drains, and equipment for CPO. Perirectal swabs were ordered monthly for all patients in non-behavioral health wards. Specimens were plated to CRE- and ESBL-selective media, and colonies identified by MALDI-TOF. The presence of the blaKPC gene was confirmed by PCR. When environmental CPO isolates were detected, EVS procedures and practices were reviewed. Results In June 2016, blaKPC+ Leclercia adecarboxylata was isolated from an EVS closet floor drain, and in August 2016, from drains in four additional closets. In the previous 10 years, Leclercia sp. was isolated just once from a clinical culture. In September 2016, routine surveillance revealed new-onset blaKPC+ L. adecarboxylata colonization in a stem cell transplant recipient. Investigation included 33 cultures collected from sink and floor drains, EVS equipment, and other items. EVS equipment, especially mop buckets, were identified as a likely point source due to their use in patient care areas and closets with contaminated floor drains. Among seven mop buckets sampled, one grew blaKPC+ L. adecarboxylata. Whole genome sequencing demonstrated genetic relatedness of the Leclercia isolates. Floor cleaner was changed to a disinfectant solution. Extensive decontamination of 67 EVS closets and equipment was performed urgently. No further patient or environmental cultures have grown blaKPC+ L. adecarboxylata. Conclusion The recovery of a highly unusual organism, rarely found in clinical specimens, that was also carrying a blaKPC+ plasmid, allowed us to detect environmental spread of this organism in the hospital. The ability to track this organism using genome sequencing provided strong evidence of the mode of spread, leading to effective remediation. No evidence-based methods exist for remediating drain contamination, which can serve as a potential reservoir for transmission. Disclosures All authors: No reported disclosures.

Surface runoff and subsurface tile drain losses of neonicotinoids and companion herbicides at edge-of-field.

PubMed

Chrétien, François; Giroux, Isabelle; Thériault, Georges; Gagnon, Patrick; Corriveau, Julie

2017-05-01

With their application as seed coatings, the use of neonicotinoid insecticides increased dramatically during the last decade. They are now frequently detected in aquatic ecosystems at concentrations susceptible to harm aquatic invertebrates at individual and population levels. This study intent was to document surface runoff and subsurface tile drain losses of two common neonicotinoids (thiamethoxam and clothianidin) compared to those of companion herbicides (atrazine, glyphosate, S-metolachlor and mesotrione) at the edge of a 22.5-ha field under a corn-soybean rotation. A total of 14 surface runoff and tile drain discharge events were sampled over two years. Events and annual unit mass losses were computed using flow-weighted concentrations and total surface runoff and tile drain flow volumes. Detection frequencies close to 100% in edge-of-field surface runoff and tile drain water samples were observed for thiamethoxam and clothianidin even though only thiamethoxam had been applied in the first year. In 2014, thiamethoxam median concentrations in surface runoff and tile drain samples were respectively 0.46 and 0.16 μg/L, while respective maximum concentrations of 2.20 and 0.44 μg/L were measured in surface runoff and tile drain samples during the first post-seeding storm event. For clothianidin, median concentrations in surface runoff and tile drain samples were 0.02 and 0.01, μg/L, and respective maximum concentrations were 0.07 μg/L and 0.05 μg/L. Surface runoff and tile drain discharge were key transport mechanisms with similar contributions of 53 and 47% of measured mass losses, respectively. Even if thiamethoxam was applied at a relatively low rate and had a low mass exportation value (0.3%), the relative toxicity was one to two orders of magnitude higher than those of the other chemicals applied in 2014 and 2015. Companion herbicides, except glyphosate in tile drains, exceeded their water quality guideline during one sampling campaign after application but rapidly resumed below these limits. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Sources and temporal dynamics of arsenic in a New Jersey watershed, USA

USGS Publications Warehouse

Barringer, J.L.; Bonin, J.L.; DeLuca, M.J.; Romagna, T.; Cenno, K.; Alebus, M.; Kratzer, T.; Hirst, B.

2007-01-01

We examined potential sources and the temporal dynamics of arsenic (As) in the slightly alkaline waters of the Wallkill River, northwestern New Jersey, where violations of water-quality standards have occurred. The study design included synoptic sampling of stream water and bed sediments in tributaries and the mainstem, hyporheic-zone/ground water on the mainstem, and seasonal and diurnal sampling of water at selected mainstem sites. The river valley is bordered by gneiss and granite highlands and shale lowlands and underlain by glacial deposits over faulted dolomites and the Franklin Marble. Ore bodies in the Marble, which have been mined for rare Zn ore minerals, also contain As minerals. Tributaries, which drain predominantly forested and agricultural land, contributed relatively little As to the river. The highest concentrations of As (up to 34????g/L) emanated from the outlet of man-made Lake Mohawk at the river's headwaters; these inputs varied substantially with season-high during warm months, low during cold months, apparently because of biological activity in the lake. Dissolved As concentrations were lower (3.3????g/L) in river water than those in ground water discharging into the riverbed (22????g/L) near the now-closed Franklin Mine. High total As concentrations (100-190??mg/kg) on the < 0.63????m fraction of bed sediments near the mine apparently result from sorption of the As in the ground-water discharge as well as from the As minerals in the streambed. As concentrations in river water were diluted during high stream flow in fall, winter and spring, and concentrated during low flow in summer. In unfiltered samples from a wetlands site, diurnal cycles in trace-element concentrations occurred; As concentrations appeared to peak during late afternoon as pH increased, but Fe, Mn, and Zn concentrations peaked shortly after midnight. The temporal variability of As and its presence at elevated concentrations in ground water and sediments as well as streamwater demonstrate the importance of (1) sampling a variety of media and (2) determining the time scales of As variability to fully characterize its passage through a river system. ?? 2007 Elsevier B.V. All rights reserved.

Heavy metal anomalies in the Tinto and Odiel River and estuary system, Spain

USGS Publications Warehouse

Nelson, C.H.; Lamothe, P.J.

1993-01-01

The Tinto and Odiel rivers drain 100 km from the Rio Tinto sulphide mining district, and join at a 20-km long estuary entering the Atlantic Ocean. A reconnaissance study of heavy metal anomalies in channel sand and overbank mud of the river and estuary by semi-quantitative emission dc-arc spectrographic analysis shows the following upstream to downstream ranges in ppm (??g g-1): As 3,000 to <200, Cd 30 to <0.1, Cu 1,500 to 10, Pb 2,000 to <10, Sb 3000 to <150, and Zn 3,000 to <200. Organic-rich (1.3-2.6% total organic carbon, TOC), sandysilty overbank clay has been analyzed to represent suspended load materials. The high content of heavy metals in the overbank clay throughout the river and estuary systems indicates the importance of suspended sediment transport for dispersing heavy metals from natural erosion and anthropogenic mining activities of the sulfide deposit. The organic-poor (0.21-0.37% TOC) river bed sand has been analyzed to represent bedload transport of naturally-occurring sulfide minerals. The sand has high concentrations of metals upstream but these decrease an order of magnitude in the lower estuary. Although heavy metal contamination of estuary mouth beach sand has been diluted to background levels estuary mud exhibits increased contamination apparently related to finer grain size, higher organic carbon content, precipitation of river-borne dissolved solids, and input of anthropogenic heavy metals from industrial sources. The contaminated estuary mud disperses to the inner shelf mud belt and offshore suspended sediment, which exhibit metal anomalies from natural erosion and mining of upstream Rio Tinto sulphide lode sources (Pb, Cu, Zn) and industrial activities within the estuary (Fe, Cr, Ti). Because heavy metal contamination of Tinto-Odiel river sediment reaches or exceeds the highest levels encountered in other river sediments of Spain and Europe, a detailed analysis of metals in water and suspended sediment throughout the system, and epidemiological analysis of heavy metal effects in humans is appropriate. ?? 1993 Estuarine Research Federation.

Comparison of Natural Drainage Group and Negative Drainage Groups after Total Thyroidectomy: Prospective Randomized Controlled Study

PubMed Central

Woo, Seung Hoon; Kim, Jin Pyeong; Park, Jung Je; Shim, Hyun Seok; Lee, Sang Ha; Lee, Ho Joong; Won, Seong Jun; Son, Hee Young; Kim, Rock Bum

2013-01-01

Purpose The aim of this study was to compare a negative pressure drain with a natural drain in order to determine whether a negative pressure drainage tube causes an increase in the drainage volume. Materials and Methods Sixty-two patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC) were enrolled in the study between March 2010 and August 2010 at Gyeongsang National University Hospital. The patients were prospectively and randomly assigned to two groups, a negative pressure drainage group (n=32) and natural drainage group (n=30). Every 3 hours, the volume of drainage was checked in the two groups until the tube was removed. Results The amount of drainage during the first 24 hours postoperatively was 41.68±3.93 mL in the negative drain group and 25.3±2.68 mL in the natural drain group (p<0.001). After 24 additional hours, the negative drain group was 35.19±4.26 mL and natural drain groups 21.53±2.90 mL (p<0.001). However, the drainage at postoperative day 3 was not statistically different between the two groups. In addition, the vocal cord palsy and temporary and permanent hypocalcemia were not different between the two groups. Conclusion These results indicate that a negative pressure drain may increase the amount of drainage during the first 24-48 hours postoperatively. Therefore, it is not necessary to place a closed suction drain when only a total thyroidectomy is done. PMID:23225820

Use of drains versus no drains after burr-hole evacuation of chronic subdural haematoma: a randomised controlled trial.

PubMed

Santarius, Thomas; Kirkpatrick, Peter J; Ganesan, Dharmendra; Chia, Hui Ling; Jalloh, Ibrahim; Smielewski, Peter; Richards, Hugh K; Marcus, Hani; Parker, Richard A; Price, Stephen J; Kirollos, Ramez W; Pickard, John D; Hutchinson, Peter J

2009-09-26

Chronic subdural haematoma causes serious morbidity and mortality. It recurs after surgical evacuation in 5-30% of patients. Drains might reduce recurrence but are not used routinely. Our aim was to investigate the effect of drains on recurrence rates and clinical outcomes. We did a randomised controlled trial at one UK centre between November, 2004, and November, 2007. 269 patients aged 18 years and older with a chronic subdural haematoma for burr-hole drainage were assessed for eligibility. 108 were randomly assigned by block randomisation to receive a drain inserted into the subdural space and 107 to no drain after evacuation. The primary endpoint was recurrence needing redrainage. The trial was stopped early because of a significant benefit in reduction of recurrence. Analyses were done on an intention-to-treat basis. This study is registered with the International Standard Randomised Controlled Trial Register (ISRCTN 97314294). Recurrence occurred in ten of 108 (9.3%) people with a drain, and 26 of 107 (24%) without (p=0.003; 95% CI 0.14-0.70). At 6 months mortality was nine of 105 (8.6%) and 19 of 105 (18.1%), respectively (p=0.042; 95% CI 0.1-0.99). Medical and surgical complications were much the same between the study groups. Use of a drain after burr-hole drainage of chronic subdural haematoma is safe and associated with reduced recurrence and mortality at 6 months. Academy of Medical Sciences, Health Foundation, and NIHR Biomedical Research Centre (Neurosciences Theme).

Pancreatic resection without routine intraperitoneal drainage

PubMed Central

Fisher, William E; Hodges, Sally E; Silberfein, Eric J; Artinyan, Avo; Ahern, Charlotte H; Jo, Eunji; Brunicardi, F Charles

2011-01-01

Background Most surgeons routinely place intraperitoneal drains at the time of pancreatic resection but this practice has recently been challenged. Objective Evaluate the outcome when pancreatic resection is performed without operatively placed intraperitoneal drains. Methods In all, 226 consecutive patients underwent pancreatic resection. In 179 patients drains were routinely placed at the time of surgery and in 47 no drains were placed. Outcomes for these two cohorts were recorded in a prospective database and compared using the χ2- /Fisher's exact test for categorical variables, and Wilcoxon's test for continuous variables. Results Demographic, surgical and pathological details were similar between the two cohorts. Elimination of routine intraperitoneal drainage did not increase the frequency or severity of serious complications. However, when all grades of complications were considered, the number of patients that experienced any complication (65% vs. 47%, P = 0.020) and the median complication severity grade (1 vs. 0, P = 0.027) were increased in the group that had drains placed at the time of surgery. Eliminating intra-operative drains was associated with decreased delayed gastric emptying (24% vs. 9%, P = 0.020) and a trend towards decreased wound infection (12% vs. 2%, P = 0.054). The readmission rate (9% vs. 17% P = 0.007) and number of patients requiring post-operative percutaneous drains (2% vs. 11%, P = 0.001) was higher in patients who did not have operatively placed drains but there was no difference in the re-operation rate (4% vs. 0%, P = 0.210). Conclusion Abandoning the practice of routine intraperitoneal drainage after pancreatic resection may not increase the incidence or severity of severe post-operative complications. PMID:21689234

40 CFR 86.532-78 - Vehicle preconditioning.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 1978 and Later New Motorcycles; Test Procedures § 86.532-78 Vehicle preconditioning. (a) The vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be drained through the provided fuel tank(s) drain(s) and charged with the specified test fuel, § 86.513, to...

40 CFR 86.532-78 - Vehicle preconditioning.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 1978 and Later New Motorcycles; Test Procedures § 86.532-78 Vehicle preconditioning. (a) The vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be drained through the provided fuel tank(s) drain(s) and charged with the specified test fuel, § 86.513, to...

40 CFR 86.532-78 - Vehicle preconditioning.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 1978 and Later New Motorcycles; Test Procedures § 86.532-78 Vehicle preconditioning. (a) The vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be drained through the provided fuel tank(s) drain(s) and charged with the specified test fuel, § 86.513, to...

40 CFR 86.532-78 - Vehicle preconditioning.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 1978 and Later New Motorcycles; Test Procedures § 86.532-78 Vehicle preconditioning. (a) The vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be drained through the provided fuel tank(s) drain(s) and charged with the specified test fuel, § 86.513, to...

40 CFR 86.532-78 - Vehicle preconditioning.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 1978 and Later New Motorcycles; Test Procedures § 86.532-78 Vehicle preconditioning. (a) The vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be drained through the provided fuel tank(s) drain(s) and charged with the specified test fuel, § 86.513, to...

Dissolved organic carbon loading from the field to watershed scale in tile-drained landscapes

USDA-ARS?s Scientific Manuscript database

Dissolved organic carbon (DOC) is an integral part to the functioning of aquatic ecosystems; yet, there is a paucity of data on DOC delivery and management in tile-drained agricultural headwater watersheds. The objective of this study was to quantify the contribution of subsurface tile drains to wat...

Surface Water and Groundwater Nitrogen Dynamics in a Well Drained Riparian Forest within a Poorly Drained Agricultural Landscape

EPA Science Inventory

The effectiveness of riparian zones in mitigating nutrients in ground and surface water depends on the climate, management and hydrogeomorphology of a site. The purpose of this study was to determine the efficacy of a well-drained, mixed-deciduous riparian forest to buffer a ri...

24 CFR 3280.611 - Vents and venting.

Code of Federal Regulations, 2014 CFR

2014-04-01

... drain piping for each toilet shall be vented by a 11/2 inch minimum diameter vent or rectangular vent of..., connected to the toilet drain by one of the following methods: (i) A 11/2 inch diameter (min.) individual vent pipe or equivalent directly connected to the toilet drain within the distance allowed in § 3280...

Leaf litter decomposition and macroinvertebrate communities in headwater streams draining pine and hardwood catchments

Treesearch

Matt R. Whiles; J. Bruce Wallace

1997-01-01

Benthic invertebrates, litter decomposition, and litterbag invertebrates were examined in streams draining pine monoculture and undisturbed hardwood catchments at the Coweeta Hydrologic Laboratory in the southern Appalachian Mountains, USA. Bimonthly benthic samples were collected from a stream draining a pine catchment at Coweeta during 1992, and compared to...

Rethinking "Brain Drain" in the Era of Globalisation

ERIC Educational Resources Information Center

Rizvi, Fazal

2005-01-01

This paper discusses a range of issues concerning the idea of "brain drain" within the context of recent thinking on transnational mobility. It argues that the traditional analyses of brain drain are not sufficient, and that we can usefully approach the topic from a postcolonial perspective concerned with issues of identity, national…

Greenhouse gas fluxes of drained organic and flooded mineral agricultural soils in the United States

USDA-ARS?s Scientific Manuscript database

Drained organic soils for agriculture represent less than 1% of the area used for crops in the United States (US). However, emission of carbon dioxide (CO2) from microbial oxidation of drained organic soils offsets almost half of the contributions that carbon sequestration of other cropping systems ...

Water movement and isoproturon behaviour in a drained heavy clay soil: 1. Preferential flow processes

NASA Astrophysics Data System (ADS)

Haria, A. H.; Johnson, A. C.; Bell, J. P.; Batchelor, C. H.

1994-12-01

The processes and mechanisms that control pesticide transport from drained heavy clay catchments are being studied at Wytham Farm (Oxford University) in southern England. In the first field season field-drain water contained high concentrations of pesticide. Soil studies demonstrated that the main mechanism for pesticide translocation was by preferential flow processes, both over the soil surface and through the soil profile via a macropore system that effectively by-passed the soil matrix. This macropore system included worm holes, shrinkage cracks and cracks resulting from ploughing. Rainfall events in early winter rapidly created a layer of saturation in the A horizon perched above a B horizon of very low hydraulic conductivity. Drain flow was initiated when the saturated layer in the A horizon extended into the upper 0.06m of the soil profile; thereafter water moved down slope via horizontal macropores possibly through a band of incorporated straw residues. These horizontal pathways for water movement connected with the fracture system of the mole drains, thus feeding the drains. Overland flow occurred infrequently during the season.

A comparative study of surgical drain placement and the use of kinesiologic tape to reduce postoperative morbidity after third molar surgery.

PubMed

Genc, Aysenur; Cakarer, Sirmahan; Yalcin, Basak Keskin; Kilic, Beril Berivan; Isler, Sabri Cemil; Keskin, Cengizhan

2018-04-19

Our aim was to compare the effects of the surgical drain and kinesiotape applications on postoperative morbidity after mandibular third molar surgery in a split-mouth study design. A single-centre, split-mouth study was performed in 23 patients who needed surgical removal of bilateral mandibular third molars. Each patient was treated with a drain tube on one side of the mandible and Kinesio tape (KT) on the contralateral side. Swelling was significantly greater in the KT group than in the drain group throughout the study period. The groups did not differ significantly in the amount of trismus at any time point. The Visual Analogue Scale (VAS)-measured pain intensity was significantly lower in the drainage group. Patients with KT had greater postoperative discomfort than those with a drain tube. All patients were generally satisfied with their treatments. Although both treatments were useful, a surgical drain was significantly more effective at reducing swelling and pain intensity than Kinesio tape. The effects of both on trismus were similar.

A Low Complexity System Based on Multiple Weighted Decision Trees for Indoor Localization

PubMed Central

Sánchez-Rodríguez, David; Hernández-Morera, Pablo; Quinteiro, José Ma.; Alonso-González, Itziar

2015-01-01

Indoor position estimation has become an attractive research topic due to growing interest in location-aware services. Nevertheless, satisfying solutions have not been found with the considerations of both accuracy and system complexity. From the perspective of lightweight mobile devices, they are extremely important characteristics, because both the processor power and energy availability are limited. Hence, an indoor localization system with high computational complexity can cause complete battery drain within a few hours. In our research, we use a data mining technique named boosting to develop a localization system based on multiple weighted decision trees to predict the device location, since it has high accuracy and low computational complexity. The localization system is built using a dataset from sensor fusion, which combines the strength of radio signals from different wireless local area network access points and device orientation information from a digital compass built-in mobile device, so that extra sensors are unnecessary. Experimental results indicate that the proposed system leads to substantial improvements on computational complexity over the widely-used traditional fingerprinting methods, and it has a better accuracy than they have. PMID:26110413

Weathering of primary minerals and mobility of major elements in soils affected by an accidental spill of pyrite tailing.

PubMed

Martín, Francisco; Diez, María; García, Inés; Simón, Mariano; Dorronsoro, Carlos; Iriarte, Angel; Aguilar, José

2007-05-25

In the present work, soil profiles were sampled 40 days and three years after an accidental pyrite tailing spill from the Aznalcóllar mine (S Spain) in order to figure out the effects of the acidic solution draining from the tailing. The composition of the acidic solution, the mineralogy, and the total and soluble content of the major elements were analysed at varying depths. The results show a weathering process of carbonates and of primary silicates. Calcium released is leached or reacts with the sulphate ions to form gypsum. Magnesium, aluminium and potassium tend to leach from the uppermost millimetres of the soil, accumulating where the pH>/=5.0; also the iron, probably forming more or less complex hydroxysulphates, precipitate in the upper 5 cm. The strong releasing of soluble salts increases the electrical conductivity, while the soluble potassium tends to decrease in the uppermost part of the soil due to the neoformation of jarosite. Iron is soluble only where the pH

A two dimensional analytical modeling of surface potential in triple metal gate (TMG) fully-depleted Recessed-Source/Drain (Re-S/D) SOI MOSFET

NASA Astrophysics Data System (ADS)

Priya, Anjali; Mishra, Ram Awadh

2016-04-01

In this paper, analytical modeling of surface potential is proposed for new Triple Metal Gate (TMG) fully depleted Recessed-Source/Dain Silicon On Insulator (SOI) Metal Oxide Semiconductor Field Effect Transistor (MOSFET). The metal with the highest work function is arranged near the source region and the lowest one near the drain. Since Recessed-Source/Drain SOI MOSFET has higher drain current as compared to conventional SOI MOSFET due to large source and drain region. The surface potential model developed by 2D Poisson's equation is verified by comparison to the simulation result of 2-dimensional ATLAS simulator. The model is compared with DMG and SMG devices and analysed for different device parameters. The ratio of metal gate length is varied to optimize the result.

The contribution of rice agriculture to methylmercury in surface waters: A review of data from the Sacramento Valley, California

USGS Publications Warehouse

Tanner, K. Christy; Windham-Myers, Lisamarie; Fleck, Jacob; Tate, Kenneth W.; McCord, Stephen A.; Linquist, Bruce A.

2017-01-01

Methylmercury (MeHg) is a bioaccumulative pollutant produced in and exported from flooded soils, including those used for rice (Oriza sativa L.) production. Using unfiltered aqueous MeHg data from MeHg monitoring programs in the Sacramento River watershed from 1996 to 2007, we assessed the MeHg contribution from rice systems to the Sacramento River. Using a mixed-effects regression analysis, we compared MeHg concentrations in agricultural drainage water from rice-dominated regions (AgDrain) to MeHg concentrations in the Sacramento and Feather Rivers, both upstream and downstream of AgDrain inputs. We also calculated MeHg loads from AgDrains and the Sacramento and Feather Rivers. Seasonally, MeHg concentrations were higher during November through May than during June through October, but the differences varied by location. Relative to upstream, November through May AgDrain least-squares mean MeHg concentration (0.18 ng L−1, range 0.15–0.23 ng L−1) was 2.3-fold higher, while June through October AgDrain mean concentration (0.097 ng L−1, range 0.6–1.6 ng L−1) was not significantly different from upstream. June through October AgDrain MeHg loads contributed 10.7 to 14.8% of the total Sacramento River MeHg load. Missing flow data prevented calculation of the percent contribution of AgDrains in November through May. At sites where calculation was possible, November through May loads made up 70 to 90% of the total annual load. Elevated flow and MeHg concentration in November through May both contribute to the majority of the AgDrain MeHg load occurring during this period. Methylmercury reduction efforts should target elevated November through May MeHg concentrations in AgDrains. However, our findings suggest that the contribution and environmental impact of rice is an order of magnitude lower than previous studies in the California Yolo Bypass.

Small-bore wire-guided chest drains: safety, tolerability, and effectiveness in pneumothorax, malignant effusions, and pleural empyema.

PubMed

Cafarotti, Stefano; Dall'Armi, Valentina; Cusumano, Giacomo; Margaritora, Stefano; Meacci, Elisa; Lococo, F; Vita, M L; Porziella, V; Bonassi, S; Cesario, Alfredo; Granone, Pierluigi

2011-03-01

The use of small-bore wire-guided chest drains for pleural effusions and pneumothorax has become popular; however, limited data are available on its efficacy and morbidity. The aim of this retrospective study is to measure, via the analysis of the so far largest reported cohort, the efficacy, safety, and tolerability of this approach in different clinical conditions. In the period from January 2002 to December 2008, 1092 patients have undergone the positioning of a small-bore wire-guided chest drain (12F) for the evidence of pneumothorax or pleural effusion and have been monitored over time for morbidity, pain at the time of insertion (measured via the visual analogue scale), and drain failure for misplacement or blockage. Patients with trauma were excluded from this study. Male/female ratio and mean age were respectively 418:674 and 55.85 ± 18.6. Three-hundred ninety-nine (36.5%) drains were inserted for pneumothorax, 324 (29.7%) for malignant effusion, 97 (8.9%) for empyema, and 272 (24.9%) for nonmalignant effusion. The pain experience was on average "very mild" (mean visual analogue scale = 4.6 mm). The overall drain failure rate was 12.9%. The percentage of successful cases was 93.8% in malignant effusion, 93% in pneumothorax, and 92.3% in nonmalignant effusion; in the cases of pathologically diagnosed empyema, drains were more likely to get blocked (74.2%). We recorded 1 serious complication within the malignant effusion group. Wire-guided 12F Seldinger-type drains are a well-tolerated and effective method of treating pneumothorax and uncomplicated pleural effusions (malignant and nonmalignant) with acceptable morbidity. The use of 12F small-bore chest drain is not indicated for the treatment of empyema. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Determining optimal fluid and air leak cut off values for chest drain management in general thoracic surgery

PubMed Central

Mesa-Guzman, Miguel; Periklis, Perikleous; Niwaz, Zakiyah; Socci, Laura; Raubenheimer, Hilgardt; Adams, Ben; Gurung, Lokesh; Uzzaman, Mohsin

2015-01-01

Background Chest drain duration is one of the most important influencing aspects of hospital stay but the management is perhaps one of the most variable aspects of thoracic surgical care. The aim of our study is to report outcomes associated with increasing fluid and air leak criteria of protocol based management. Methods A 6-year retrospective analysis of protocolised chest drain management starting in 2007 with a fluid criteria of 3 mL/kg increasing to 7 mL/kg in 2011 to no fluid criteria in 2012, and an air leak criteria of 24 hours without leak till 2012 when digital air leak monitoring was introduced with a criteria of <20 mL/min of air leak for more than 6 hours. Patient data were obtained from electronic hospital records and digital chest films were reviewed to determine the duration of chest tube drainage and post-drain removal complications. Results From 2009 to 2012, 626 consecutive patients underwent thoracic surgery procedures under a single consultant. A total of 160 did not require a chest drain and data was missing in 22, leaving 444 for analysis. The mean age [standard deviation (SD)] was 57±19 years and 272 (61%) were men. There were no differences in the incidence of pneumothoraces (P=0.191), effusion (P=0.344) or re-interventions (P=0.431) for drain re-insertions as progressively permissive criteria were applied. The median drain duration dropped from 1-3 days (P<0.001) and accordingly hospital stay reduced from 4-6 days (P<0.001). Conclusions Our results show that chest drains can be safely removed without fluid criteria and air leak of less than 20 mL/min with median drain duration of 1 day, associated with a reduced length of hospital stay. PMID:26716045

Difference in growth and coalescing patterns of droplets on bi-philic surfaces with varying spatial distribution.

PubMed

Garimella, Martand Mayukh; Koppu, Sudheer; Kadlaskar, Shantanu Shrikant; Pillutla, Venkata; Abhijeet; Choi, Wonjae

2017-11-01

This paper reports the condensation and subsequent motion of water droplets on bi-philic surfaces, surfaces that are patterned with regions of different wettability. Bi-philic surfaces can enhance the water collection efficiency: droplets condensing on hydrophobic regions wick into hydrophilic drain channels when droplets grow to a certain size, renewing the condensation on the dry hydrophobic region. The onset of drain phenomenon can be triggered by multiple events with distinct nature ranging from gravity, direct contact between a droplet and a drain channel, to a mutual coalescence between droplets. This paper focuses on the effect of the length scale of hydrophobic regions on the dynamics of mutual coalescence between droplets and subsequent drainage. The main hypothesis was that, when the drop size is sufficient, the kinetic energy associated with a coalescence of droplets may cause dynamic advancing of a newly formed drop, leading to further coalescence with nearby droplets and ultimately to a chain reaction. We fabricate bi-philic surfaces with hydrophilic and hydrophobic stripes, and the result confirms that coalescing droplets, when the length scale of droplets increases beyond 0.2mm, indeed display dynamic expansion and chain reaction. Multiple droplets can thus migrate to hydrophilic drain simultaneously even when the initial motion of the droplets was not triggered by the direct contact between the droplet and the hydrophilic drain. Efficiency of drain due to mutual coalescence of droplets varies depending on the length scale of bi-philic patterns, and the drain phenomenon reaches its peak when the width of hydrophobic stripes is between 800μm and 1mm. The Ohnesorge number of droplets draining on noted surfaces is between 0.0042 and 0.0037 respectively. The observed length scale of bi-philic patterns matches that on the Stenocara beetle's fog harvesting back surface. This match between length scales suggests that the surface of the insect is optimized for the drain of harvested water. Copyright © 2017 Elsevier Inc. All rights reserved.

Ecotoxicologic impacts of agricultural drain water in the Salinas River, California, USA.

PubMed

Anderson, Brian S; Hunt, John W; Phillips, Bryn M; Nicely, Patricia A; Gilbert, Kristine D; de Vlaming, Victor; Connor, Valerie; Richard, Nancy; Tjeerdema, Ronald S

2003-10-01

The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California (USA). Large areas of this watershed are cultivated year-round in row crops, and previous laboratory studies have demonstrated that acute toxicity of agricultural drain water to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. We investigated chemical contamination and toxicity in waters and sediments in the river downstream of an agricultural drain water input. Ecological impacts of drain water were investigated by using bioassessments of macroinvertebrate community structure. Toxicity identification evaluations were used to characterize chemicals responsible for toxicity. Salinas River water downstream of the agricultural drain was acutely toxic to the cladoceran Ceriodaphnia dubia, and toxicity to C. dubia was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to the amphipod Hyalella azteca, a resident invertebrate. Toxicity identification evaluations (TIEs) conducted on sediment pore water suggested that toxicity to amphipods was due in part to OP pesticides; concentrations of chlorpyrifos in pore water sometimes exceeded the 10-d mean lethal concentration (LC50) for H. azteca. Potentiation of toxicity with addition of the metabolic inhibitor piperonyl butoxide suggested that sediment toxicity also was due to other non-metabolically activated compounds. Macroinvertebrate community structure was highly impacted downstream of the agricultural drain input, and a number of macroinvertebrate community metrics were negatively correlated with combined TUs of chlorpyrifos and diazinon, as well as turbidity associated with the drain water. Some macroinvertebrate metrics were also correlated with bank vegetation cover. This study suggests that pesticide pollution is the likely cause of ecological damage in the Salinas River, and this factor may interact with other stressors associated with agricultural drain water to impact the macroinvertebrate community in the system.

Draining characteristics of hemispherically bottomed cylinders in a low-gravity environment

NASA Technical Reports Server (NTRS)

Symons, E. P.

1978-01-01

An experimental investigation was conducted to study the phenomenon of vapor ingestion during the draining of a scale model, hemispherically bottomed cylindrical tank in a low-gravity environment. Where possible, experimental results are compared with previously obtained numerical predictions. It was observed that certain combinations of Weber and Bond number resulted in draining-induced axisymmetric slosh motion. The periods of the slosh waves were correlated with the square root of the draining parameter, the ratio (Weber number)/(Bond number plus one), as was the quantity of liquid remaining in the tank when vapor was ingested into the outlet line.

Advances in chest drain management in thoracic disease

PubMed Central

George, Robert S.

2016-01-01

An adequate chest drainage system aims to drain fluid and air and restore the negative pleural pressure facilitating lung expansion. In thoracic surgery the post-operative use of the conventional underwater seal chest drainage system fulfills these requirements, however they allow great variability amongst practices. In addition they do not offer accurate data and they are often inconvenient to both patients and hospital staff. This article aims to simplify the myths surrounding the management of chest drains following chest surgery, review current experience and explore the advantages of modern digital chest drain systems and address their disease-specific use. PMID:26941971

N Channel JFET Based Digital Logic Gate Structure

NASA Technical Reports Server (NTRS)

Krasowski, Michael J (Inventor)

2013-01-01

An apparatus is provided that includes a first field effect transistor with a source tied to zero volts and a drain tied to voltage drain drain (Vdd) through a first resistor. The apparatus also includes a first node configured to tie a second resistor to a third resistor and connect to an input of a gate of the first field effect transistor in order for the first field effect transistor to receive a signal. The apparatus also includes a second field effect transistor configured as a unity gain buffer having a drain tied to Vdd and an uncommitted source.

The effects of vault drainage on postoperative morbidity after vaginal hysterectomy for benign gynaecological disease: a randomised controlled trial.

PubMed

Dua, A; Galimberti, A; Subramaniam, M; Popli, G; Radley, S

2012-02-01

To evaluate the efficacy of vault drainage in reducing the immediate postoperative morbidity associated with vaginal hysterectomy carried out for benign gynaecological conditions. Randomised controlled trial. A tertiary referral gynaecology centre in UK. A total of 272 women who underwent vaginal hysterectomy for benign conditions between March 2005 and June 2010. The 272 women were randomised to have a drain inserted or not inserted, 'drain' or 'no drain', respectively, before vault closure during vaginal hysterectomy, using a sealed envelope technique. The surgical procedures were performed using the surgeons' standard technique and postoperative care was delivered according to the unit's protocol. The primary outcome measure was reduction in postoperative febrile morbidity. Secondary outcome measures were hospital readmission rate, blood transfusion, change in postoperative haemoglobin and length of stay. In all, 135 women were randomised to have a drain and 137 to 'no drain'. There were no differences in the incidence of febrile morbidity, length of stay, change in haemoglobin or need for postoperative blood transfusion between the two groups. The routine use of vault drain at vaginal hysterectomy for benign disorders has no significant effect on postoperative morbidity. The use of vault drain in this context is not recommended. © 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.

Meta-Analysis of Drainage Versus No Drainage After Laparoscopic Cholecystectomy

PubMed Central

Lucarelli, Pierino; Di Filippo, Annalisa; De Angelis, Francesco; Stipa, Francesco; Spaziani, Erasmo

2014-01-01

Background and Objectives: Routine drainage after laparoscopic cholecystectomy is still controversial. This meta-analysis was performed to assess the role of drains in reducing complications in laparoscopic cholecystectomy. Methods: An electronic search of Medline, Science Citation Index Expanded, Scopus, and the Cochrane Library database from January 1990 to June 2013 was performed to identify randomized clinical trials that compare prophylactic drainage with no drainage in laparoscopic cholecystectomy. The odds ratio for qualitative variables and standardized mean difference for continuous variables were calculated. Results: Twelve randomized controlled trials were included in the meta-analysis, involving 1939 patients randomized to a drain (960) versus no drain (979). The morbidity rate was lower in the no drain group (odds ratio, 1.97; 95% confidence interval, 1.26 to 3.10; P = .003). The wound infection rate was lower in the no drain group (odds ratio, 2.35; 95% confidence interval, 1.22 to 4.51; P = .01). Abdominal pain 24 hours after surgery was less severe in the no drain group (standardized mean difference, 2.30; 95% confidence interval, 1.27 to 3.34; P < .0001). No significant difference was present with respect to the presence and quantity of subhepatic fluid collection, shoulder tip pain, parenteral ketorolac consumption, nausea, vomiting, and hospital stay. Conclusion: This study was unable to prove that drains were useful in reducing complications in laparoscopic cholecystectomy. PMID:25516708

Non-equilibrium Green's functions study of discrete dopants variability on an ultra-scaled FinFET

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

Valin, R., E-mail: r.valinferreiro@swansea.ac.uk; Martinez, A., E-mail: a.e.Martinez@swansea.ac.uk; Barker, J. R., E-mail: john.barker@glasgow.ac.uk

In this paper, we study the effect of random discrete dopants on the performance of a 6.6 nm channel length silicon FinFET. The discrete dopants have been distributed randomly in the source/drain region of the device. Due to the small dimensions of the FinFET, a quantum transport formalism based on the non-equilibrium Green's functions has been deployed. The transfer characteristics for several devices that differ in location and number of dopants have been calculated. Our results demonstrate that discrete dopants modify the effective channel length and the height of the source/drain barrier, consequently changing the channel control of the charge. Thismore » effect becomes more significant at high drain bias. As a consequence, there is a strong effect on the variability of the on-current, off-current, sub-threshold slope, and threshold voltage. Finally, we have also calculated the mean and standard deviation of these parameters to quantify their variability. The obtained results show that the variability at high drain bias is 1.75 larger than at low drain bias. However, the variability of the on-current, off-current, and sub-threshold slope remains independent of the drain bias. In addition, we have found that a large source to drain current by tunnelling current occurs at low gate bias.« less

Method of making self-aligned lightly-doped-drain structure for MOS transistors

DOEpatents

Weiner, Kurt H.; Carey, Paul G.

2001-01-01

A process for fabricating lightly-doped-drains (LDD) for short-channel metal oxide semiconductor (MOS) transistors. The process utilizes a pulsed laser process to incorporate the dopants, thus eliminating the prior oxide deposition and etching steps. During the process, the silicon in the source/drain region is melted by the laser energy. Impurities from the gas phase diffuse into the molten silicon to appropriately dope the source/drain regions. By controlling the energy of the laser, a lightly-doped-drain can be formed in one processing step. This is accomplished by first using a single high energy laser pulse to melt the silicon to a significant depth and thus the amount of dopants incorporated into the silicon is small. Furthermore, the dopants incorporated during this step diffuse to the edge of the MOS transistor gate structure. Next, many low energy laser pulses are used to heavily dope the source/drain silicon only in a very shallow region. Because of two-dimensional heat transfer at the MOS transistor gate edge, the low energy pulses are inset from the region initially doped by the high energy pulse. By computer control of the laser energy, the single high energy laser pulse and the subsequent low energy laser pulses are carried out in a single operational step to produce a self-aligned lightly-doped-drain-structure.

Effect of defect creation and migration on hump characteristics of a-InGaZnO thin film transistors under long-term drain bias stress with light illumination

NASA Astrophysics Data System (ADS)

Cho, Yong-Jung; Kim, Woo-Sic; Lee, Yeol-Hyeong; Park, Jeong Ki; Kim, Geon Tae; Kim, Ohyun

2018-06-01

We investigated the mechanism of formation of the hump that occurs in the current-voltage I-V characteristics of amorphous InGaZnO (a-IGZO) thin film transistors (TFTs) that are exposed to long-term drain bias stress under illumination. Transfer characteristics showed two-stage degradation under the stress. At the beginning of the stress, the I-V characteristics shifted in the negative direction with a degradation of subthreshold slope, but the hump phenomenon developed over time in the I-V characteristics. The development of the hump was related to creation of defects, especially ionized oxygen vacancies which act as shallow donor-like states near the conduction-band minimum in a-IGZO. To further investigate the hump phenomenon we measured a capacitance-voltage C-V curve and performed two-dimensional device simulation. Stretched-out C-V for the gate-to-drain capacitance and simulated electric field distribution which exhibited large electric field near the drain side of TFT indicated that VO2+ were generated near the drain side of TFT, but the hump was not induced when VO2+ only existed near the drain side. Therefore, the degradation behavior under DBITS occurred because VO2+ were created near the drain side, then were migrated to the source side of the TFT.

Tracking natural and anthropogenic origins of dissolved arsenic during surface and groundwater interaction in a post-closure mining context: Isotopic constraints.

PubMed

Khaska, Mahmoud; Le Gal La Salle, Corinne; Verdoux, Patrick; Boutin, René

2015-01-01

Arsenic contamination of stream waters and groundwater is a real issue in Au-As mine environments. At the Salsigne Au-As mine, southern France, arsenic contamination persists after closure and remediation of the site. In this study, natural and anthropogenic arsenic inputs in surface water and groundwater are identified based on (87)Sr/(86)Sr, and δ(18)O and δ(2)H isotopic composition of water. In the wet season, downstream of the remediated zone, the arsenic contents in stream water and alluvial aquifer groundwater are high, with values in the order of 36 μg/L and 40 μg/L respectively, while upstream natural background average concentrations are around 4 μg/L. Locally down-gradient of the reclaimed area, arsenic concentrations in stream water showed 2 peaks, one during an important rainy event (101 mm) in the wet season in May, and a longer one over the dry period, reaching 120 and 110 μg/L respectively. The temporal variations in arsenic content in stream water can be explained i) during the dry season, by release of arsenic stored in the alluvial sediments through increased contribution from base flow and decreased stream flow and ii) during major rainy events, by mobilization of arsenic associated with important surface runoff. The (87)Sr/(86)Sr ratios associated with increasing arsenic content in stream waters downstream of the reclaimed area are significantly lower than that of the natural Sr inherited from Variscan formations. These low (87)Sr/(86)Sr ratios are likely to be associated with the decontaminating water treatment processes, used in the past and still at present, where CaO, produced from marine limestone and therefore showing a low (87)Sr/(86)Sr ratios, is used to precipitate Ca3(AsO4)2. The low Sr isotope signatures will then impact on the Sr isotope ratio of (1) the Ca-arsenate stored in tailing dams, (2) effluent currently produced by water treatment process and (3) groundwater draining from the overall site. Furthermore, Δ(2)H shows that the low (87)Sr/(86)Sr ratio, arsenic rich water is characterized by an evaporated signature suggesting a potential influence of water impacted by evaporation during storage in decantation lagoons. This study shows the suitability of Sr and stable isotopes of water as tracers to differentiate natural and anthropogenic sources of arsenic release or other trace elements from mining context where CaO is used for water treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

Tracking natural and anthropogenic origins of dissolved arsenic during surface and groundwater interaction in a post-closure mining context: Isotopic constraints

NASA Astrophysics Data System (ADS)

Khaska, Mahmoud; Le Gal La Salle, Corinne; Verdoux, Patrick; Boutin, René

2015-06-01

Arsenic contamination of stream waters and groundwater is a real issue in Au-As mine environments. At the Salsigne Au-As mine, southern France, arsenic contamination persists after closure and remediation of the site. In this study, natural and anthropogenic arsenic inputs in surface water and groundwater are identified based on 87Sr/86Sr, and δ18O and δ2H isotopic composition of water. In the wet season, downstream of the remediated zone, the arsenic contents in stream water and alluvial aquifer groundwater are high, with values in the order of 36 μg/L and 40 μg/L respectively, while upstream natural background average concentrations are around 4 μg/L. Locally down-gradient of the reclaimed area, arsenic concentrations in stream water showed 2 peaks, one during an important rainy event (101 mm) in the wet season in May, and a longer one over the dry period, reaching 120 and 110 μg/L respectively. The temporal variations in arsenic content in stream water can be explained i) during the dry season, by release of arsenic stored in the alluvial sediments through increased contribution from base flow and decreased stream flow and ii) during major rainy events, by mobilization of arsenic associated with important surface runoff. The 87Sr/86Sr ratios associated with increasing arsenic content in stream waters downstream of the reclaimed area are significantly lower than that of the natural Sr inherited from Variscan formations. These low 87Sr/86Sr ratios are likely to be associated with the decontaminating water treatment processes, used in the past and still at present, where CaO, produced from marine limestone and therefore showing a low 87Sr/86Sr ratios, is used to precipitate Ca3(AsO4)2. The low Sr isotope signatures will then impact on the Sr isotope ratio of (1) the Ca-arsenate stored in tailing dams, (2) effluent currently produced by water treatment process and (3) groundwater draining from the overall site. Furthermore, Δ2H shows that the low 87Sr/86Sr ratio, arsenic rich water is characterized by an evaporated signature suggesting a potential influence of water impacted by evaporation during storage in decantation lagoons. This study shows the suitability of Sr and stable isotopes of water as tracers to differentiate natural and anthropogenic sources of arsenic release or other trace elements from mining context where CaO is used for water treatment.

The Crystals Cave in a test tube

NASA Astrophysics Data System (ADS)

Puig, C.; Romero, M. L.

2012-04-01

It's quite easy to understand formation of crystals in Nature by evaporation of the solutions that contain minerals, but many times we have realised that our pupils hardly understand that precipitation is a process mostly caused by changing parameters in a solution, like pH, temperature, etc. and not necessarily depending on evaporation. We propose a hands-on activity using the context of the Cave of the Crystals in Naica's mine, Mexico. The Crystals Cave is a wonderful place where giant crystals of selenite (gypsum) have grown feeding from a supersaturated anhydrite solution1. Miners discovered the cave filled with hot water, and drained it to explore the gallery. The cave is now a giant laboratory where scientists are looking for the keys to understand geological processes. Teaching sequence (for students 15 years old) is as follows: DISCOVERING A MARVELLOUS PLACE: We showed our pupils several images and a short video of the Cave of the Crystals and ask them about the process that may have caused the phenomenon. Whole-class discussion. PRESENTING A CHALLENGE TO OUR STUDENTS: "COULD WE CREATE A CRYSTALS CAVE IN A TEST TUBE?" EXPERIMENTING TO IMITATE NATURE: Students tried to grow crystals simulating the same conditions as those in Naica's mine. We have chosen KNO3, a salt more soluble than gypsum. We added 85 g of salt to 200 ml of water (solubility of KNO3 at 25°C is 36 g per 100 gr of water) and heated it until it is dissolved. Afterwards, we poured the solution into some test tubes and other recipients and let them cool at room temperature. And they got a beautiful crystals cave!! THINKING A LITTLE MORE: we asked pupils some questions to make them think about the process and to predict what would happen in different situations. For example: a) What would happen with crystals if we heated the tubes again? or b) What would happen if we took the remaining solution from the tubes and keep it in the fridge? PROVING A NEW HYPOTHESIS: Pupils collected the remaining solutions from all the containers, poured them in a Petri dish and let them inside the fridge for a day: New crystals grew at the bottom of the Petri dishes!!! LOOKING FOR THE SCIENTIFIC EXPLANATIONS: We made them work in pairs in order to find an explanation about giant crystals in Naica's mine, by using short videos2, a scientific article or any information they can find on line. THINKING OF FUTURE: Should we close Naica's mine in order to preserve it? Whole-class discussion

Controlling attachment and growth of Listeria monocytogenes in PVC model floor drains using a peroxide chemical, chitosan/arginine or heat

USDA-ARS?s Scientific Manuscript database

Listeria monocytogenes enters a poultry further processing plant with raw product and colonizes the plant as a resident in floor drains. We have shown that L. monocytogenes can escape floor drains, becoming airborne during wash down, creating potential for contamination of fully cooked product. Li...

Controlling attachment and growth of listeria monocytogenes in polyvinyl chloride model floor drains using a peroxide chemical, chitosan-arginine, or heat

USDA-ARS?s Scientific Manuscript database

Listeria monocytogenes can colonize a poultry processing or further processing plant as a resident in floor drains. Limiting growth and attachment to drain surfaces may help lessen the potential for cross contamination of product. The objective of this study was to compare a synthetic hydrogen per...

30 CFR 816.72 - Disposal of excess spoil: Valley fills/head-of-hollow fills.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., 6-hour precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a... as the fill is not located in an area containing intermittent or perennial streams. A rock-core... upstream drainage is diverted around the fill. The alternative rock-core chimney drain system shall be...

30 CFR 816.72 - Disposal of excess spoil: Valley fills/head-of-hollow fills.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., 6-hour precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a... as the fill is not located in an area containing intermittent or perennial streams. A rock-core... upstream drainage is diverted around the fill. The alternative rock-core chimney drain system shall be...

30 CFR 816.72 - Disposal of excess spoil: Valley fills/head-of-hollow fills.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., 6-hour precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a... as the fill is not located in an area containing intermittent or perennial streams. A rock-core... upstream drainage is diverted around the fill. The alternative rock-core chimney drain system shall be...

30 CFR 816.72 - Disposal of excess spoil: Valley fills/head-of-hollow fills.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., 6-hour precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a... as the fill is not located in an area containing intermittent or perennial streams. A rock-core... upstream drainage is diverted around the fill. The alternative rock-core chimney drain system shall be...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2013 CFR

2013-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2012 CFR

2012-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2014 CFR

2014-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2010 CFR

2010-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2011 CFR

2011-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

An Exact Solution to the Draining Reservoir Problem of the Incompressible and Non-Viscous Liquid

ERIC Educational Resources Information Center

Hong, Seok-In

2009-01-01

The exact expressions for the drain time and the height, velocity and acceleration of the free surface are found for the draining reservoir problem of the incompressible and non-viscous liquid. Contrary to the conventional approximate results, they correctly describe the initial time dependence of the liquid velocity and acceleration. Torricelli's…

Development of Thermal Bridging Factors for Use in Energy Models

DTIC Science & Technology

2015-06-20

assemblies. 5.2.2 Drainage : Drained systems Drained (Figure 5-6) and screened enclosures assume some rainwater will penetrate the outer surface...38 5.2.2 Drainage : Drained systems ...layer (e.g., drainage plane and gap or waterproofing) 2. Airflow control layer (e.g., an air barrier system ) 3. Thermal control layer (e.g., insulation

Novel pod for chlorine dioxide generation and delivery to control aerobic bacteria on the inner surface of floor drains

USDA-ARS?s Scientific Manuscript database

Floor drains in poultry processing and further processing plants are a harborage site for bacteria both free swimming and in biofilms. This population can include Listeria monocytogenes which has been shown to have potential for airborne spreading from mishandled open drains. Chlorine dioxide (ClO...

75 FR 29520 - Agency Information Collection Activities; Submission for Office of Management and Budget Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-26

... section 1404(b) of the Act (``Drain Cover Standard''). In addition to the anti-entrapment devices or... system; gravity drainage system; automatic pump shut-off system or drain disablement. The Pool and Spa... the drain covers, anti-entrapment device/systems, sump or equalizer lines at the site; and report on...

Influence of thinning operations on the hydrology of a drained coastal plantation watershed

Treesearch

Johnny M. Grace; R.W. Skaggs; H.R. Malcom; G.M. Chescheir; D.K. Cassel

2003-01-01

Forest management activities such as harvesting, thinning, and site preparation can affect the hydrologic behavior of watersheds on poorly drained soils. The effects of thinning on hydrology are presented for an artificially drained pine plantation paired watershed in eastern North Carolina. Outflow and water table depths were monitored over a 3-year study period...

30 CFR 816.72 - Disposal of excess spoil: Valley fills/head-of-hollow fills.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., 6-hour precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a... as the fill is not located in an area containing intermittent or perennial streams. A rock-core... upstream drainage is diverted around the fill. The alternative rock-core chimney drain system shall be...

Disinfection of drain water of tomato by means of UV radiation and slow sand filtration in real greenhouse circumstances.

PubMed

De Rocker, E; Goen, K; Van Poucke, K

2006-01-01

The efficiency of the disinfection of drain water was tested at 11 greenhouses with tomato cultivation on rockwool substrate in Flanders (Belgium) by means of mycological analysis. In addition the presence of phytopathogenic fungi in the drain water was analysed at 2 supplementary greenhouses with recirculation without disinfection.

77 FR 70357 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

... replacing the drain tube assemblies and support clamps on the aft fairing of the engine struts. This new AD requires replacing the drain tube assembly of the left and right engine strut aft fairings with a new one... require replacing the drain tube assembly of the left and right engine strut aft fairings with a new one...

Volatilization of low vapor pressure--volatile organic compounds (LVP-VOCs) during three cleaning products-associated activities: Potential contributions to ozone formation.

PubMed

Shin, Hyeong-Moo; McKone, Thomas E; Bennett, Deborah H

2016-06-01

There have been many studies to reduce ozone formation mostly from volatile organic compound (VOC) sources. However, the role of low vapor pressure (LVP)-VOCs from consumer products remains mostly unexplored and unaddressed. This study explores the impact of high production volume LVP-VOCs on ozone formation from three cleaning products-associated activities (dishwashing, clothes washing, and surface cleaning). We develop a model framework to account for the portion available for ozone formation during the use phase and from the down-the-drain disposal. We apply experimental studies that measured emission rates or models that were developed for estimating emission rates of organic compounds during the use phase. Then, the fraction volatilized (fvolatilized) and the fraction disposed down the drain (fdown-the-drain) are multiplied by the portion available for ozone formation for releases to the outdoor air (fO3|volatilized) and down-the-drain (fO3|down-the-drain), respectively. Overall, for chemicals used in three specific cleaning-product uses, fvolatilized is less than 0.6% for all studied LVP-VOCs. Because greater than 99.4% of compounds are disposed of down the drain during the use phase, when combined with fO3|volatilized and fO3|down-the-drain, the portion available for ozone formation from the direct releases to outdoor air and the down-the-drain disposal is less than 0.4% and 0.2%, respectively. The results from this study indicate that the impact of the studied LVP-VOCs on ozone formation is very sensitive to what occurs during the use phase and suggest the need for future research on experimental work at the point of use. Copyright © 2016 Elsevier Ltd. All rights reserved.