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USGS2013

Arsenic in New Jersey Coastal Plain streams, sediments, and shallow groundwater: effects from different geologic sources and anthropogenic inputs on biogeochemical and physical mobilization processes

Arsenic (As) concentrations in New Jersey Coastal Plain streams generally exceed the State Surface Water Quality Standard (0.017 micrograms per liter (µg/L)), but concentrations seldom exceed 1 µg/L in filtered stream-water samples, regardless of geologic contributions or anthropogenic inputs. Nevertheless, As concentrations in unfiltered stream water indicate substantial variation because of particle inputs from soils and sediments with differing As contents, and because of discharges from groundwater of widely varying chemistry. In the Inner Coastal Plain, streams draining to lower reaches of the Delaware River traverse As-rich glauconitic sediments of marine origin in which As contents typically are about 20 milligrams per kilogram (mg/kg) or greater. In some of these sedimentary units, As concentrations exceed the New Jersey drinking-water maximum contaminant level (5 µg/L) in shallow groundwater that discharges to streams. Microbes, fueled by organic carbon beneath the streambed, reduce iron (Fe) and As, releasing As and Fe into solution in the shallow groundwater from geologic materials that likely include (in addition to glauconite) other phyllosilicates, apatite, and siderite. When the groundwater discharges to the stream, the dissolved Fe and As are oxidized, the Fe precipitates as a hydroxide, and the As sorbs or co-precipitates with the Fe. Because of the oxidation/precipitation process, dissolved As concentrations measured in filtered stream waters of the Inner Coastal Plain are about 1 µg/L, but the total As concentrations (and loads) are greater, substantially amplified by As-bearing suspended sediment in stormflows. In the Outer Coastal Plain, streams draining to the Atlantic Ocean traverse quartz-rich sediments of mainly deltaic origin where the As content generally is low (<8 mg/kg). In unfiltered and filtered water samples, As concentrations typically are less than 1 µg/L in the acidic stream water and groundwater of the Outer Coastal Plain, but are greater in waters from urban areas. Despite the generally small geologic contributions to Outer Coastal Plain groundwater, where wastewater inputs were indicated, concentrations of As in unfiltered shallow groundwater discharging to small urban streams exceeded the maximum contaminant level. With a history of agriculture in the New Jersey Coastal Plain, anthropogenic inputs of As, such as residues from former pesticide applications in soils, can amplify any geogenic As in runoff. Such inputs contribute to an increased total As load to a stream at high stages of flow. As a result of yet another anthropogenic influence, microbes that reduce and mobilize As beneath the streambeds are stimulated by inputs of dissolved organic carbon (DOC). Although DOC is naturally occurring, anthropogenic contributions from wastewater inputs may deliver increased levels of DOC to subsurface soils and ultimately groundwater. Arsenic concentrations may increase with the increases in pH of groundwater and stream water in developed areas receiving wastewater inputs, as As mobilization caused by pH-controlled sorption and desorption reactions are likely to occur in waters of neutral or alkaline pH (for example, Nimick and others, 1998; Barringer and others, 2007b). Because of the difference in As content of the geologic materials in the two sub-provinces of the Coastal Plain, the amount of As that is mobile in groundwater and stream water is, potentially, substantially greater in the Inner Coastal Plain than in the Outer Coastal Plain. In turn, streams within the Inner and Outer Coastal Plain can receive substantially more As in groundwater discharge from developed areas than from environments where DOC appears to be of natural origin.

New Jersey↗

USGS2015

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

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 km 2 . 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.

California↗

USGS2009

Toxicological significance of soil ingestion by wild and domestic animals

Most wild and domestic animals ingest some soil or sediment, and some species may routinely, or under special circumstances, ingest considerable amounts. Ingested soil supplies nutrients, exposes animals to parasites and pathogens, and may play a role in developing immune systems. 1 Soil ingestion is also sometimes the principal route of exposure to various environmental contaminants. 2-7 Ingestion of soil and earthy material is defined as geophagy and may be either intentional or unintentional, occurring as an animal eats or grooms.

Book chapter↗

USGS1994

Effect of atrazine on potential denitrification in aquifer sediments

Agriculturaf use of fertilizers and herbicides has often resulted in nitrate and atrazine contamination of the shallow aquifers that underlay cultivated fields. In several cases, the concentrations of atrazine and nitrate dissolved in ground water are positively correlated (Spalding ef al., 1979; Chen and Druliner, 1987; Spalding et al., 1989). Because simultaneous application of nitrate fertilizers and the herbicide, atrazine, is common, the co-occurrence of these contaminants in ground water is not entirely unexpected. However, the possibility also exists that this co-occurrence may ret&t interactions of atrazine with nitrate in the subsurface environment. R&ton and Cervelh (1980), McElhannon ei al. (1984) and Mills (1984) have reported that atrazine inhibits denitrification in‘soil’lf this i‘s indeed the case, atrazine contamination may contribute to nitrate preservation and accumulation in anaerobic aquifers by inhibiting denitrification, the principal mechanism for nitrate removal in anaerobic systems. Huwever, the effect of atrazine on the rate of denit~ficat~on in soils remains controversial, because atrazine has been reported variously to enhance denitrification (Cervelli and Ralston, 1983) or to have no effect on denitrification in soils (Bollag and Henninger, 1976; Yeomans and Bremner, IQ85, 1987). Moreover, the effect of dissolved atrazine concentrations on the rate of denitrification in aquifer sediments has not been reported. Our purpose was to determine the elects of dissolved atrazine concentrations on potential rates ofdenitri~~t~on in aquifer sediments from two different agricultural areas to evaluate the hypothesis that, by inhibiting denitrification, atrazine contributes to nitrate preservation in anaerobic aquifer systems.

Soil Biology and Biochemistry↗

USGS2011

Assessment of soil-gas, seep, and soil contamination at the North Range Road Landfill, Fort Gordon, Georgia, 2008-2009

Soil gas, seeps, and soil were assessed for contaminants at the North Range Road Landfill at Fort Gordon, Georgia, from October 2008 to September 2009. The assessment included delineating organic contaminants present in soil-gas samples beneath the area estimated to be the landfill and in water samples collected from three seeps at the base of the landfill. Inorganic contaminants were determined in three seep samples and in soil samples. This assessment was conducted to provide environmental contamination data to Fort Gordon pursuant to requirements for the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. All soil-gas samples collected contained total petroleum hydrocarbons above the method detection level. The highest total petroleum hydrocarbon mass detected was nearly 50 micrograms (μg) in a soil-gas sample from one of the three seeps. The highest BTEX mass detected was 0.83 μg in a soil-gas sample collected near the same seep. Some soil-gas samples had perchloroethylene (known as PCE) mass greater than the method detection level of 0.01 microgram. The highest PCE mass detected was 0.73 μg, and PCE mass was detected in soil gas in areas upgradient of the seeps and indicates that the seep contamination may be related to previous waste-disposal activities upgradient of the seeps No organic or semivolatile compounds in the seep samples were detected above their respective maximum contaminant levels established in the U.S. Environmental Protection Agency National Primary Drinking Water Standards. PCE was detected in water from all three seeps at concentrations between 0.85 and 0.95 microgram per liter. Trimethylsilanol was detected in water collected from all three seeps and may be related to the degradation of silicone-based materials commonly disposed of in landfills. Inorganic concentrations in water samples from one seep did not exceed any maximum contaminant levels in the National Secondary Drinking Water Standards. In water from one seep, however, iron was detected at 865 micrograms per liter, which exceeds the maximum contaminant level for iron in the Secondary Drinking Water Standard, and in water from the other seep, iron and manganese were detected at 492,000 and 10,700 micrograms per liter, repectively, both of which exceed the respective maximum contaminant levels for the Secondary Drinking Water Standard. Water from one of the seeps had concentrations of cadmium, copper, and zinc that exceed Georgia standards for in-stream water quality, and concentrations of arsenic and lead that exceed their respective maximum contaminant levels for the Primary Drinking Water Standards. Inorganic concentrations in all four soil samples did not exceed regional screening levels established by the U.S. Environmental Protection Agency. Barium concentrations, however, were two to three times higher than the background concentrations reported in similar Coastal Plain sediments of South Carolina.

Open-File Report↗

USGS1996

South Florida wetlands ecosystem; biogeochemical processes in peat

The South Florida wetlands ecosystem is an environment of great size and ecological diversity (figs. 1 and 2). The landscape diversity and subtropical setting of this ecosystem provide a habitat for an abundance of plants and wildlife, some of which are unique to South Florida. South Florida wetlands are currently in crisis, however, due to the combined effects of agriculture, urbanization, and nearly 100 years of water management. Serious problems facing this ecosystem include (1) phosphorus contamination producing nutrient enrichment, which is causing changes in the native vegetation, (2) methylmercury contamination of fish and other wildlife, which poses a potential threat to human health, (3) changes in the natural flow of water in the region, resulting in more frequent drying of wetlands, loss of organic soils, and a reduction in freshwater flow to Florida Bay, (4) hypersalinity, massive algal blooms, and seagrass loss in parts of Florida Bay, and (5) a decrease in wildlife populations, especially those of wading birds. This U.S. Geological Survey (USGS) project focuses on the role of organic-rich sediments (peat) of South Florida wetlands in regulating the concentrations and impact of important chemical species in the environment. The cycling of carbon, nitrogen, phosphorus, and sulfur in peat is an important factor in the regulation of water quality in the South Florida wetlands ecosystem. These elements are central to many of the contamination issues facing South Florida wetlands, such as nutrient enrichment, mercury toxicity, and loss of peat. Many important chemical and biological reactions occur in peat and control the fate of chemical species in wetlands. Wetland scientists often refer to these reactions as biogeochemical processes, because they are chemical reactions usually mediated by microorganisms in a geological environment. An understanding of the biogeochemical processes in peat of South Florida wetlands will provide a basis for evaluating the effects on water quality of (1) constructing buffer wetlands to alleviate nutrient contamination and (2) replumbing the ecosystem to restore natural water flow. The results may also suggest new approaches for solving problems of contamination and water quality in these wetlands. A second focus of this project will be on the geochemical history of the South Florida ecosystem. Peat is a repository of the history of past environmental conditions in the wetland. Before effective action can be taken to correct many of the problems facing these wetlands, we must first study the biogeochemistry of the peat at depth in order to understand whether current problems are the result of recent human activity or are part of a long-term natural cycle. Coordination with other (USGS) projects for South Florida is ongoing. These projects are studying the biological history of the ecosystem by using pollen and shells buried in the peat, together with procedures for dating the peat at various depths, to develop an overall ecosystem history model, with emphasis on the last 100 years.

Fact Sheet↗

USGS2013

Potential Environmental and Environmental-Health Implications of the SAFRR Tsunami Scenario in California: Chapter F in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

The California Tsunami Scenario models the impacts of a hypothetical, yet plausible, tsunami caused by an earthquake offshore from the Alaska Peninsula. In this chapter, we interpret plausible tsunami-related contamination, environmental impacts, potential for human exposures to contaminants and hazardous materials, and implications for remediation and recovery. Inundation-related damages to major ports, boat yards, and many marinas could release complex debris, crude oil, various fuel types and other petroleum products, some liquid bulk cargo and dry bulk cargo, and diverse other pollutants into nearby coastal marine environments and onshore in the inundation zone. Tsunami-induced erosion of contaminated harbor bottom sediments could re-expose previously sequestered metal and organic pollutants (for example, organotin or DDT). Inundation-related damage to many older buildings could produce debris containing lead paint, asbestos, pesticides, and other legacy contaminants. Intermingled household debris and externally derived debris and sediments would be left in flooded buildings. Post tsunami, mold would likely develop in inundated houses, buildings, and debris piles. Tsunamigenic fires in spilled oil, debris, cargo, vehicles, vegetation, and residential, commercial, or industrial buildings and their contents would produce potentially toxic gases and smoke, airborne ash, and residual ash/debris containing caustic alkali solids, metal toxicants, asbestos, and various organic toxicants. Inundation of and damage to wastewater treatment plants in many coastal cities could release raw sewage containing fecal solids, pathogens, and waste chemicals, as well as chemicals used to treat wastewaters. Tsunami-related physical damages, debris, and contamination could have short- and longer-term impacts on the environment and the health of coastal marine and terrestrial ecosystems. Marine habitats in intertidal zones, marshes, sloughs, and lagoons could be damaged by erosion or sedimentation, and could receive an influx of debris, metal and organic contaminants, and sewage-related pathogens. Debris and re-exposed contaminated sediments would be a source of sea- or rain-water-leachable metal and organic contaminants that could pose chronic toxicity threats to ecosystems. If human populations are successfully evacuated prior to the tsunami arrival, there would be no or limited numbers of drownings, other casualties, or related injuries, wounds, and infections. Immediately after the tsunami, human populations away from the inundation zone could be transiently exposed to airborne gases, smoke, and ash from tsunamigenic fires. Cleanup and disposal, particularly of hazardous materials, would pose substantial logistical challenges and economic costs. Given the high value of the coastal residential and commercial properties in the inundation zone, it can be postulated that there would be substantial insurance claims for environmental restoration, mold mitigation, disposal of debris that contains hazardous materials, and costs of litigation related to environmental liability. Post-tsunami cleanup, if done with appropriate mitigation (for example, dust control), personal protection, and disposal measures, would help reduce the potential for cleanup-worker and resident exposures to toxicants and pathogens in harbor waters, debris, soils, ponded waters, and buildings. A number of other steps can be taken by governments, businesses, and residents to help reduce the environmental impacts of tsunamis and to recover more quickly from these environmental impacts. For example, development of State and local policies that foster rapid assessment of potential contamination, as well as rapid decision making for disposal options should hazardous debris or sediment be identified, would help enhance recovery by speeding cleanup.

California↗

USGS2007

A framework for assessing the sustainability of monitored natural attenuation

The sustainability of monitored natural attenuation (MNA) over time depends upon (1) the presence of chemical/biochemical processes that transform wastes to innocuous byproducts, and (2) the availability of energy to drive these processes to completion. The presence or absence of contaminant-transforming chemical/biochemical processes can be determined by observing contaminant mass loss over time and space (mass balance). The energy available to drive these processes to completion can be assessed by measuring the pool of metabolizable organic carbon available in a system, and by tracing the flow of this energy to available electron acceptors (energy balance). For the special case of chlorinated ethenes in ground-water systems, for which a variety of contaminant-transforming biochemical processes exist, natural attenuation is sustainable when the pool of bioavailable organic carbon is large relative to the carbon flux needed to drive biodegradation to completion. These principles are illustrated by assessing the sustainability of MNA at a chlorinated ethene-contaminated site in Kings Bay, Georgia. Approximately 1,000 kilograms of perchloroethene (PCE) was released to a municipal landfill in the 1978-1980 timeframe, and the resulting plume of chlorinated ethenes migrated toward a nearby housing development. A numerical model, built using the sequential electron acceptor model code (SEAM3D), was used to quantify mass and energy balance in this system. The model considered the dissolution of non-aqueous phase liquid (NAPL) as the source of the PCE, and was designed to trace energy flow from dissolved organic carbon to available electron acceptors in the sequence oxygen > chlorinated ethenes > ferric iron > sulfate > carbon dioxide. The model was constrained by (1) comparing simulated and measured rates of ground-water flow, (2) reproducing the observed distribution of electron-accepting processes in the aquifer, (3) comparing observed and measured concentrations of chlorinated ethenes, and (4) reproducing the observed production and subsequent dilution of dissolved chloride, a final degradation product of chloroethene biodegradation. Simulations using the constrained model indicated that an average flux of 5 milligrams per liter per day of organic carbon (CH2O) per model cell (25 square meters) is required to support the short-term sustainability of MNA. Because this flux is small relative to the pool of renewable organic carbon (about 4.7 x 107 milligrams [mg] per model cell) present in the soil zone and non-renewable carbon (about 6.9 x 108 mg per model cell) in an organic-rich sediment layer overlying the aquifer, the long-term sustainability of MNA is similarly large. This study illustrates that the short- and long-term sustainability of MNA can be assessed by: 1. Estimating the time required for contaminants to dissolve/disperse/degrade under ambient hydrologic conditions (time of remediation). 2. Quantifying the organic carbon flux to the system needed to consume competing electron acceptors (oxygen) and direct electron flow toward chloroethene degradation (short-term sustainability). 3. Comparing the required flux of organic carbon to the pool of renewable and non-renewable organic carbon given the estimated time of remediation (long-term sustainability). These are general principles that can be used to assess the sustainability of MNA in any hydrologic system.

Circular↗

USGS1993

Arsenate inhibition of denitrification in nitrate contaminated sediments

Short-term and chronic exposure effects of arsenic on sediment denitrification were evaluated. N 2 O production rates were determined for As-contaminated (chronic treatment) and uncontaminated (short-term treatment) sediments exposed to a range of As concentrations. The As-containing sediments, collected from an herbicide-contaminated shallow aquifer, exhibited significantly lower rates of denitrification with increasing As concentration. With glucose amendment, denitrification rates were ca 10nmol N 2 Og −1 h −1 higher than in unamended treatments, but a similar trend of decreasing N 2 O production with increasing As concentration was observed. For the uncontaminated sediment, short-term increases in As concentration reduced the rate of denitrification only under glucose amended conditions. This response suggests that carbon limitation is also an important factor influencing denitrification in these sediments. These results indicate that by inhibiting the denitrification potential of the in situ microbial community, As contamination may contribute to nitrate accumulation in shallow aquifers, which underlie cultivated land.

Soil Biology and Biochemistry↗

USGS2013

Variable contributions of mercury from groundwater to a first-order urban coastal plain stream in New Jersey, USA

Filtered total mercury (FTHg) concentrations in a rapidly urbanizing area ranged from 50 to 250 ng/L in surface waters of the Squankum Branch, a tributary to a major river (Great Egg Harbor River (GEHR)) traversing both urban and forested/wetland areas in the Coastal Plain of New Jersey. An unsewered residential area with Hg-contaminated well water (one of many in the region) is adjacent to the stream’s left bank. Although the region’s groundwater contains total Hg (THg) at background levels of <10 ng/L, water from about 700 domestic wells in urbanized areas completed in the acidic, quartzose unconfined aquifer typically at depths 20 to 30 m below land surface has been found to exceed 2,000 ng/L (the USEPA maximum contaminant level). Within urbanized areas, THg concentrations in shallow groundwater (<20 m below land surface at or near the water table) and the potential for Hg transport were not well known, representing a considerable knowledge gap. Sampling of streamwater in, and groundwater discharge to, the Squankum Branch watershed revealed that concentrations of THg generally were in the range of 1 to 10 ng/L, but narrow plumes (“plumelets”) of shallow groundwater discharging to the stream from the opposing banks contained FTHg at a concentration > 5,000 ng/L (left bank) and nearly 2,000 ng/L (right bank). The Hg content of bankside soils and sediments was high (up to 12 mg/kg) and mostly acid leachable where groundwater with high Hg concentrations discharged, indicating contributions of Hg by both runoff and shallow groundwater. Elevated concentrations of nutrients and chloride in some groundwater plumelets likely indicated inputs from septic-system effluent and (or) fertilizer applications. The Hg probably derives mainly from mercurial pesticide applications to the former agricultural land being urbanized. The study results show that soil disturbance and introduction of anthropogenic substances can mobilize Hg from soils to shallow groundwater and the Hg contamination travels in narrow plumelets to discharge points such as stream tributaries. In the entire GEHR watershed, THg concentrations in groundwater discharging to streams in urban areas tended to be higher than concentrations in water discharging to streams of forested areas, consistent with the results from this small watershed. Other areas with similar quartzose coastal aquifers, land-use history, and hydrogeology may be similarly vulnerable to Hg contamination of shallow groundwater and associated surface water.

New Jersey↗

USGS2015

Trace-metal and organic constituent concentrations in bed sediment at Big Base and Little Base Lakes, Little Rock Air Force Base, Arkansas—Comparisons to sediment-quality guidelines and indications for timing of exposure

This report compares concentrations for a wide range of inorganic and organic constituents in bed sediment from Big Base Lake and Little Base Lake, which are located on Little Rock Air Force Base, Arkansas, to sediment-quality guidelines. This report also compares trace-metal concentrations in a bed-sediment core sample to sediment age to determine when the highest concentrations of trace metals were deposited in Big Base Lake. Trace-metal results often were higher than background concentrations in the surrounding Pulaski County area, and concentrations of arsenic, cadmium, cobalt, copper, lead, manganese, mercury, nickel, and zinc at one or more of three study sites were higher than median concentrations for a study involving 98 urban streams in seven metropolitan areas of the United States. Concentrations for most polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides in all three bed-sediment samples were less than the laboratory reporting limit or were detected at low concentrations. Some contaminants were detected at concentrations that are potentially toxic to sediment-dwelling biota; however, in general, the analyses suggest that the risk of sediment toxicity may be relatively low. Threshold effect concentrations were exceeded for 14 constituents—arsenic, copper, lead, nickel, and zinc, five polycyclic aromatic hydrocarbons compounds, chlordane, and all three dichlorodiphenyltrichloroethane (DDT) congeners—which suggests potential toxicity to some sediment-dwelling biota. Only two constituents had concentrations that exceeded published probable effect concentrations—arsenic (at the deepest site in Big Base Lake, NS6) and p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE; at both sites in Big Base Lake, NS5 and NS6). Regarding highest concentrations and associated timing of exposure, trace metals analyzed in the sediment core seem to indicate three fairly distinct exposure patterns. For 11 trace metals that had the highest concentration measured in the shallowest and most recently deposited sediment, the most likely explanation is recent exposure by anthropogenic activities. Most of the 11 trace metals with highest concentrations in shallow sediment are relatively innocuous; however, arsenic, copper, selenium, and zinc are among the U.S. Environmental Protection Agency’s 126 priority pollutants. For three trace metals (cadmium, lead, and mercury), for which concentrations were highest in sediments that were 16–20 centimeters down the core, it is likely that a source associated with those contaminants during the period when those sediments were deposited, was reduced or eliminated. The eight remaining trace metals, for which concentrations were highest in sediments that were just below the prereservoir surface, likely had sources that were eliminated soon after lake construction or occurred at relatively high background concentrations in soils in the area around Little Rock Air Force Base.

Arkansas↗

USGS2020

Groundwater quality and geochemistry of West Virginia’s southern coal fields

Coal mining has been the dominant industry and land use in West Virginia’s southern coal fields since the mid-1800s. Mortality rates for a variety of serious chronic conditions, such as diabetes, heart disease, and some forms of cancer in Appalachian coal mining regions, are higher than in areas lacking substantial coal mining activity within the Appalachian Region or elsewhere in the United States. Causes of the increased mortality and morbidity are not clear, but poor diet, high rates of smoking, socioeconomic factors, and the quality of groundwater used by area residents are all possible contributing factors. This study was conducted by the U.S. Geological Survey in cooperation with the West Virginia Department of Health and Human Resources and the West Virginia Department of Environmental Protection, with grant support from the Centers for Disease Control and Prevention (CDC) to assess the quality of groundwater in southern West Virginia. The data from this assessment of groundwater quality may be used by the CDC and other agencies to potentially investigate the role or lack thereof of groundwater quality with respect to mortality and morbidity rates in the region. The study was conducted in a region where a high density of current or past coal mining combined with a lack of advanced sewage treatment could affect concentrations of commonly occurring constituents plus contaminants, including nitrate, trace metals, major ions, indicator bacteria, radon, hydrogen sulfide, and dissolved hydrocarbons. Because rural residential wells and mine outfalls are considered private sources of water in the region, and are therefore unregulated and unmonitored, water-quality data are sparse. To fill the data gap and assess the groundwater quality in the region, water-quality samples were collected from 60 sites in a 10-county area. The 60 sites sampled included 46 rural residential homeowner wells and 14 mine outfall discharges used for residential supply. For this study, all samples were collected prior to any filtration or other treatments, typically at the pressure tank, and are indicative of total and dissolved constituents in the untreated water. Generally, data for the 60 sites indicate that most waters sampled do not exceed thresholds for most U.S. Environmental Protection Agency (EPA) drinking-water standards and U.S. Geological Survey (USGS) drinking-water screening criteria. However, there were several notable exceptions. Turbidity exceeded the 5-Nephelometric Turbidity Unit (NTU) EPA treatment technique (TT) drinking-water standard in 14 of 60 (23 percent) sites sampled and exceeded the 1-NTU TT standard in 51 of 60 (85 percent) sites sampled. Turbidity is common in many wells in southern West Virginia and may be attributed to iron oxyhydroxide precipitates, sediment carried into the aquifers from the shallow soil zone due to improperly constructed or cased wells or transported to the aquifer in shallow stress-relief fracture zones or through permeable bedding-plane partings. For the sites sampled, 31 of 60 (52 percent) had pH values at, above, or below the upper and lower range of the EPA Secondary Maximum Contaminant Level (SMCL, 6.5–8.5 standard units). Of those 31 sites, 28 (90 percent) were indicative of acidic corrosive water and 3 (10 percent) were indicative of alkaline water. The Langelier Saturation Index (LSI), which is a measure of the corrosivity of the water, was computed for all sites sampled for the study. Eighty-two percent of the sites sampled had waters that were classified as corrosive, based on a LSI less than −0.5. Corrosive water has the potential to leach lead, copper, and other metals from lead, copper, galvanized, or lead-tin soldered connections in water lines. The chloride to sulfate mass ratio also was assessed with the alkalinity to indicate the potential to promote galvanic corrosion (PPGC) of water lines and plumbing fixtures. Only one of the sites (1.7 percent) classified as a corrosive water site, had a PPGC considered high; the remaining sites were classified as having either a moderate (53.3 percent) or low (45 percent) PPGC. Therefore, the type of plumbing systems sampled for this study may be affected by corrosive water, but the potential for leaching trace metals and other constituents from residential plumbing systems containing older galvanized pipes or lead-tin soldered copper pipes is moderate to low. The indicator bacteria total coliform and Escherichia coli ( E. coli ) also were detected in groundwater samples to varying degrees. Total coliforms, which are a broad class of indicator bacteria, are common in groundwater in southern West Virginia and were detected in 39 of the 60 sites (65 percent) sampled. The presence of total coliform bacteria is a potential indicator of surface contamination, due to improperly constructed or cased wells, or infiltration of soil or other surface contaminants into the aquifer or well bore. E. coli bacteria, however, are much more indicative of fecal contamination of groundwater from either human or animal sources, and 14 of the 60 (23 percent) sites sampled had detections of E. coli . Although only a few strains of E. coli are known pathogens, their presence in groundwater may be an indicator of other related pathogens such as viruses and should be regarded as a serious potential issue. Water treatment such as chlorination, ozonation, or ultraviolet light may be appropriate to kill potential pathogenic bacteria or viruses in the source water. Manganese and iron were prevalent contaminants in the groundwater samples collected for this study, with 30 of 60 (50 percent) sites analyzed for manganese and 25 of 60 (42 percent) sites analyzed for iron exceeding the proposed 50- and 300-micrograms per liter (µg/L) SMCL drinking-water standards, respectively, for aesthetic criteria such as taste, odor, or staining of plumbing fixtures. Fourteen of the 60 sites sampled (23 percent) had concentrations of manganese that exceeded the 300-µg/L USGS health-based screening level, and 1 site exceeded the 1,600-µg/L EPA drinking-water equivalent level, which is based on a lifetime exposure level. Sodium is another common constituent in groundwater within the study area. Sodium has an EPA health-based value (HBV) of 20 milligrams per liter (mg/L) for individuals who are on a sodium-restricted diet for blood pressure or other health reasons. Sodium concentrations exceeded the 20-mg/L EPA HBV in 27 of 60 (45 percent) samples. Radon, a naturally occurring carcinogenic radioactive gas known to cause lung cancer, was detected at concentrations at or exceeding the proposed 300-picocuries per liter (pCi/L) EPA Maximum Contaminant Level (MCL) in 12 of the 60 (20 percent) sites sampled. Sites with radon gas concentrations exceeding the 300-pCi/L proposed MCL have the potential for airborne concentrations of radon to exceed the 4-pCi/L indoor air standard. Inhalation of radon can cause lung cancer, and the 4-pCi/L indoor air standard is based on an inhalation standard. Therefore, homeowners whose wells have radon gas concentrations exceeding 300 pCi/L may be advised to have their indoor air tested to determine if indoor air concentrations exceed the 4-pCi/L indoor air standard established by the EPA. Various factors were analyzed statistically and graphically to determine whether they have an influence on groundwater quality within the study area, including topographic setting, well depth, type of mining (surface or underground), type of site (well or mine outfall), and geologic formation. Only geologic formation and the type of site sampled had strong statistical correlations with one or more of the constituents of concern for this study. The overall chemistry of outfalls (mine outfalls) and wells was significantly different, with a much higher dissolved oxygen content in outfalls than in wells. The dissolved oxygen content is the primary component driving the oxidation and reduction of minerals, and the precipitation of minerals that are saturated or super saturated with respect to various cations and anions. Median dissolved oxygen concentrations for the outfalls sampled was 8.75 mg/L, and only 0.4 mg/L for the wells sampled. Median concentrations of sulfate and selenium were much higher in waters from the outfalls sampled, with median concentrations of 73.75 mg/L and 2.35 µg/L, respectively, compared to the wells sampled, which had median concentrations of 18.3 mg/L and less than (<) the 0.05-µg/L method detection limit, respectively. The maximum selenium concentration was for a well, with a concentration of 16.6 µg/L. The geochemical processes that control sulfate and selenium concentrations in groundwater are similar and are the result of the oxidation of sulfide minerals such as pyrite and ferroselite. Iron and manganese concentrations were elevated in most of the wells sampled, with median concentrations of 269.5 and 124.5 µg/L, respectively, but were rarely detected in the outfalls sampled, with median concentrations of < 4.0 and < 0.4 µg/L, respectively. The difference in iron and manganese between wells and outfalls is indicative of the role of dissolved oxygen on processes controlling groundwater chemistry in the region. Three principal geologic formations were assessed for the study, and the overall chemistry for the Pocahontas, New River, and Kanawha Formations varied substantially with respect to several constituents. Concentrations of calcium, magnesium, and total dissolved solids were highest for sites sampled in the Pocahontas Formation, with median concentrations of 41.9, 18.6, and 312 mg/L, respectively. For constituents that are commonly associated with mining activity, the highest concentrations were for sites sampled in the New River Formation, with median concentrations of iron and manganese of 2,450 µg/L and 482 µg/L, respectively, and a median pH of 6.35 standard units. Concentrations of barium also were elevated in samples collected from sites in the New River Formation, with a median barium concentration of 184 µg/L. The source of the barium is not fully known but may be associated with commingling of shallow groundwater with deeper brines or dissolution of the mineral barite. The highest median sulfate concentrations were from sites sampled in the Pocahontas Formation, with a median concentration of 64.0 mg/L. Of the 12 sites at or exceeding the 300-pCi/L proposed drinking-water standard for radon, 8 (67 percent of MCL exceedances) were for sites deriving water from the Kanawha Formation, 3 (25 percent of MCL exceedances) were for sites deriving water from the New River Formation, and only 1 site was for water from the Pocahontas Formation (8 percent of proposed MCL exceedances). Dissolved hydrocarbons, including methane, ethane, propane, propene, n - and i -butane, 1-butene, n - and i -pentane, pentane, 2- and 3-ethyl pentane, hexane, and benzene were analyzed in samples collected from 59 of the 60 sites to assess the potential occurrence and sources of these trace gases in groundwater within the study area. Results of the analysis indicate that most of the gas is of shallow biogenic origin, possibly associated with coal-bed methane, but a subset of samples has a gas signature and a chloride to bromide ratio indicative of potential mixing with deeper thermogenic gases. Only 2 of the 59 (3.3 percent) sites sampled had concentrations of methane gas, which is a highly combustible and explosive gas, exceeding the 10 milligrams per kilogram level of concern established by the U.S. Office of Surface Mining Reclamation and Enforcement. Principal components analysis was used to assess the primary geochemical processes occurring in the aquifers sampled. The first principal component had significant positive loadings for bromide, chloride, silica, ammonia, barium, iron, manganese, and arsenic, and significant negative loadings for dissolved oxygen, potassium, nitrate, and uranium, and reflects reduction and oxidation (redox) processes occurring in deeper anoxic groundwater or shallow oxic groundwater. The strong positive loadings for iron, manganese, barium, and arsenic are correlated with reducing conditions often found deeper in the aquifer. More oxic water is correlated with oxidation of nitrogen species to nitrate and environmental mobilization of uranium and sulfate in shallow wells and mine outfalls.

West Virginia↗

USGS2012

Groundwater quality in the Columbia Plateau, Snake River Plain, and Oahu basaltic-rock and basin-fill aquifers in the Northwestern United States and Hawaii, 1992-2010

This assessment of groundwater-quality conditions of the Columbia Plateau, Snake River Plain, and Oahu for the period 1992–2010 is part of the U.S. Geological Survey’s National Water Quality Assessment (NAWQA) program. It shows where, when, why, and how specific water-quality conditions occur in groundwater of the three study areas and yields science-based implications for assessing and managing the quality of these water resources. The primary aquifers in the Columbia Plateau, Snake River Plain, and Oahu are mostly composed of fractured basalt, which makes their hydrology and geochemistry similar. In spite of the hydrogeologic similarities, there are climatic differences that affect the agricultural practices overlying the aquifers, which in turn affect the groundwater quality. Understanding groundwater-quality conditions and the natural and human factors that control groundwater quality is important because of the implications to human health, the sustainability of rural agricultural economies, and the substantial costs associated with land and water management, conservation, and regulation. The principal regional aquifers of the Columbia Plateau, Snake River Plain, and Oahu are highly vulnerable to contamination by chemicals applied at the land surface; essentially, they are as vulnerable as many shallow surficial aquifers elsewhere. The permeable and largely unconfined character of principal aquifers in the Columbia Plateau, Snake River Plain, and Oahu allow water and chemicals to infiltrate to the water table despite depths to water commonly in the hundreds of feet. The aquifers are essentially unconfined over large areas, having few extensive clay layers to impede infiltration through permeable volcanic rock and alluvial sediments. Agriculture is intensive in all three study areas, and heavy irrigation has imposed large artificial flows of irrigation recharge that rival or exceed natural recharge rates. Fertilizers and pesticides applied at land surface are leached from soil and transported to deep water tables with the infiltrating irrigation recharge, resulting in a layer of degraded water quality overlying better quality regional groundwater beneath. This “irrigation-recharge layer” is best known on Oahu, where it has been studied since the 1960s; however, the extent of nitrate and pesticide contamination in the Columbia Plateau and Snake River Plain indicate that the same situation exists in those areas. Contamination from agricultural and urban activities is present not only at shallow depths in surficial materials of the three areas, but extends regionally in the deep, principal bedrock aquifers that are tapped for drinking water by domestic and public-supply wells. Naturally occurring constituents and nitrate concentrations above human-health benchmarks—Maximum Contaminant Levels (MCLs), and Health-Based Screening Levels (HBSLs)—were more common in the Columbia Plateau and the Snake River Plain than in Oahu. Concentrations of anthropogenic constituents (constituents related to human activities) above human-health benchmarks were more common in Oahu. Naturally occurring contaminants, such as arsenic and radon, may be present in groundwater at concentrations of potential concern for human health in relatively undeveloped settings that otherwise may not be perceived as susceptible to contamination. Even though the median depth to groundwater in Oahu is more than 300 feet, the common occurrence of anthropogenic compounds in groundwater indicates that Oahu has a high susceptibility to contamination. Nitrate concentrations in groundwater were above the national background concentrations of 1 milligram per liter (mg/L) in all three study areas. In the Columbia Plateau, nitrate exceeded the human-health benchmark of 10 mg/L in 20 percent of the wells sampled. In the Snake River Plain, nitrate exceeded the human-health benchmark of 10 mg/L in 3 percent of the wells sampled. Nitrate can persist in groundwater for years and even decades in the oxygen-rich groundwater of the Columbia Plateau and the Snake River Plain, so prudent groundwater protection measures are critical to protect drinking water resources by reducing nitrate leaching from the land surface. Nitrate logistic regression models indicated that areas with a high percentage of land in crops (such as potatoes or sugarcane) and soils with low amounts of organic matter are most likely to have elevated nitrate concentrations in the groundwater. Areas where agricultural activities were absent had much lower probabilities of detecting elevated nitrate concentrations. The Columbia Plateau had a much higher probability of having elevated nitrate concentrations, with most of the land area having greater than a 50 percent probability of elevated nitrate concentrations. Oahu and the Snake River Plain had a much lower probability of having elevated nitrate concentrations because of their lower percentage of agricultural land. Pesticides were detected at many sites in groundwater of the Columbia Plateau, Snake River Plain, and Oahu but generally at low concentrations below human-health benchmarks. Atrazine and its degradate (a compound produced from the breakdown of a parent pesticide), deethylatrazine, were the most commonly detected pesticides in groundwater sampled in the Columbia Plateau and Snake River Plain. Bromacil was the most commonly detected pesticide on Oahu. The other pesticides most commonly detected in the study areas include simazine, hexazinone, metribuzin, diuron, prometon, metolachlor, p,p’ -DDE, dieldrin, 2-4-D, and alachlor. DDE (a degradate of DDT) and dieldrin are still being detected in groundwater despite having been banned for more than 30 years. Codetection of multiple pesticides in water from a single well was common. The widespread occurrence of pesticides in groundwater in the study areas indicates that the groundwater is highly susceptible to pesticide contamination. Some pesticides were detected in groundwater samples from all three study areas, but other pesticides were detected only in samples from Oahu, or only in samples from the Columbia Plateau and Snake River Plain. This is because some pesticides (such as atrazine) are broad-spectrum pesticides that are used on many crops in many different areas of the United States. Other pesticides (such as simazine, metribuzin, and metolachlor) are used on row crops (such as potatoes, barley, and alfalfa) grown in the Columbia Plateau and Snake River Plain, but not on pineapple or sugarcane grown in Oahu. Atrazine logistic-regression models indicate that areas with a high percentage of land in crops (such as potatoes or sugarcane), a low percentage of fallow land, and highly permeable soils with low amounts of organic matter are most likely to have atrazine detected in the groundwater. Areas where agricultural activities were absent had much lower probabilities of atrazine being detected. The Snake River Plain had a much higher probability of atrazine detections, with more than 50 percent of the land area having greater than a 50 percent probability of atrazine contamination. Oahu had a much lower probability of atrazine contamination, with only 24 percent of the land area having greater than a 50 percent probability of atrazine contamination. Oahu and the Columbia Plateau had some of the highest percentages of soil fumigant detections in groundwater in the United States. Soil fumigants are volatile organic compounds (VOCs) used as pesticides, which are applied to soils to reduce populations of plant parasitic nematodes (harmful rootworms), weeds, fungal pathogens, and other soil-borne microorganisms. They are used in Oahu and the Columbia Plateau on crops such as pineapple and potatoes. All three areas (Columbia Plateau, Snake River Plain, and Oahu) had fumigant concentrations exceeding human-health benchmarks for drinking water.

Hawai'i, Idaho, Nevada, Oregon, Utah, Washington, ↗

USGS1995

Handbook of ecotoxicology

The Handbook of Ecotoxicology offers 34 chapters with contributions from over 50 selected international experts. The book is divided into four major sections: I. Quantifying and Measuring Ecotoxicological Effects, II. Contaminant Sources and Effects, III. Case Histories and Ecosystem Surveys, and IV. Methods for Making Estimates and Predictability in Ecotoxicology. Concepts and methodology are presented for many types of aquatic and terrestrial ecotoxicity test protocols for both controlled and field assessments. Chapters are offered on such diverse topics as sediment and soil ecotoxicity, landscape indicators, biomonitoring, and use of current bioindicators. The roles of deforestation and global warming, pathogens and disease in ecotoxicology, abiotic factors, urban runoff, predictive ecotoxicology, population modeling, and restoration ecology are discussed. This book was designed to serve as a reference book for students entering the fields of ecotoxicology, aquatic toxicology, terrestrial wildlife toxicology, and other environmental sciences. Many portions of this handbook will serve as a convenient reference text for established investigators, resource managers, and those involved in risk assessment and risk management within regulatory agencies and the private sector.

Book↗

USGS1977

Water-quality study of Tulpehocken Creek, Berks County, Pennsylvania, prior to impoundment of Blue Marsh Lake

Blue Marsh Lake is planned as a multipurpose impoundment to be constructed on Tulpehocken Creek near Bernville, Berks County, Pennsylvania. Prior to construction, samples of water, bed material, and soil were collected throughout the impoundment site to determine concentrations of nutrients, insecticides, trace metals, suspended sediment, and bacteria. Analyses of water suggest the Tulpehocken Creek basin to be a highly fertile environment. Nitrogen and phosphorus concentrations near the proposed dam site had median values of 4.5 and 0.13 mg/L, respectively. Suspended sediment discharges average between 100 and 200 tons (90.7 to 181.4 metric tons) per day during normal flows but may exceed 10,000 tons (9,070 metric tons) per day during storm runoff. Highest yields were measured during winter and early spring. Concentrations range from 3 mg/L to more than 500 mg/L. Bed material samples contain trace quantities of aldrin, DDT, DDD, DDE, dieldrin, and chlordane. Polychlorinated biphyenyls (PCB's) ranged from 10 to 100 μg/kg. Soils at the impoundment site are of average fertility. However, the silt loam texture is ideal for attachment and growth of aquatic plants. Bacteria populations indicative of recent fecal contamination are prevalent in the major inflows to the proposed lake. Fecal Coliform exceeded the standards recommended by the Federal Water Pollution Administration Committee on Water Quality Criteria for public water supply in 29 percent of the monthly samples, and exceeded the recommended public bathing waters standard in 83 percent of the samples collected from June to September. Arsenic from an industrial waste was found in the water, suspended sediment, and bed material of Tulpehocken Creek in concentrations of 0 to 30 μg/l, 2 to 879 μg/l, and 1 to 79 μg/g, respectively. It represents a potential environmental hazard; however, the measured concentrations are less than that known to be harmful to man, fish, or wildlife, according to published water quality criteria.

Pennsylvania↗

USGS1993

Distribution of volatile organic compounds in soil vapor in the vicinity of a defense fuel supply point, Hanahan, South Carolina

Two passive soil-vapor sampling techniques were used in the vicinity of a defense fuel supply point in Hanahan, South Carolina, to identify areas of potential contamination of the shallow water table aquifer by volatile organic compounds (VOC's). Both techniques involved the burial of samplers in the vadose zone and the saturated bottom sediments of nearby streams. One method, the empty-tube technique, allowed vapors to pass through a permeable membrane and accumulate inside an inverted empty test tube. A sample was extracted and analyzed on site by using a portable gas chromatograph. As a comparison to this method, an activated-carbon technique, also was used in certain areas. This method uses a vapor collector consisting of a test tube containing activated carbon as a sorbent for VOC's.

Water-Resources Investigations Report↗

USGS2011

Assessment of soil-gas and soil contamination at the South Prong Creek Disposal Area, Fort Gordon, Georgia, 2009-2010

Soil gas and soil were assessed for contaminants at the South Prong Creek Disposal Area at Fort Gordon, Georgia, from October 2009 to September 2010. The assessment included identifying and delineating organic contaminants present in soil-gas and inorganic contaminants present in soil samples collected from the area estimated to be the South Prong Creek Disposal Area, including two seeps and the hyporheic zone. This assessment was conducted to provide environmental contamination data to Fort Gordon personnel pursuant to requirements for the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. All soil-gas samplers in the two seeps and the hyporheic zone contained total petroleum hydrocarbons above the method detection level. The highest total petroleum hydrocarbon concentration detected from the two seeps was 54.23 micrograms per liter, and the highest concentration in the hyporheic zone was 344.41 micrograms per liter. The soil-gas samplers within the boundary of the South Prong Creek Disposal Area and along the unnamed road contained total petroleum hydrocarbon mass above the method detection level. The highest total petroleum hydrocarbon mass detected was 147.09 micrograms in a soil-gas sampler near the middle of the unnamed road that traverses the South Prong Creek Disposal Area. The highest undecane mass detected was 4.48 micrograms near the location of the highest total petroleum hydrocarbon mass. Some soil-gas samplers detected undecane mass greater than the method detection level of 0.04 micrograms, with the highest detection of toluene mass of 109.72 micrograms in the same location as the highest total petroleum hydrocarbon mass. Soil-gas samplers installed in areas of high contaminant mass had no detections of explosives and chemical agents above their respective method detection levels. Inorganic concentrations in five soil samples did not exceed regional screening levels established by the U.S. Environmental Protection Agency. Barium concentrations, however, were up to four times higher than the background concentrations reported in similar Coastal Plain sediments of South Carolina.

Open-File Report↗

USGS2007

Assessment of contamination from arsenical pesticide use on orchards in the great valley region, Virginia and West Virginia, USA

Lead arsenate pesticides were widely used in apple orchards from 1925 to 1955. Soils from historic orchards in four counties in Virginia and West Virginia contained elevated concentrations of As and Pb, consistent with an arsenical pesticide source. Arsenic concentrations in approximately 50% of the orchard site soils and approximately 1% of reference site soils exceed the USEPA Preliminary Remediation Goal (PRG) screening guideline of 22 mg kg-1 for As in residential soi, defined on the basis of combined chronic exposure risk. Approximately 5% of orchard site soils exceed the USEPA PRG for Pb of 400 mg kg-1 in residential soil; no reference site soils sampled exceed this value. A variety of statistical methods were used to characterize the occurrence, distribution, and dispersion of arsenical pesticide residues in soils, stream sediments, and ground waters relative to landscape features and likely background conditions. Concentrations of Zn, Pb, and Cu were most strongly associated with high developed land density and population density, whereas elevated concentrations of As were weakly correlated with high orchard density, consistent with a pesticide residue source. Arsenic concentrations in ground water wells in the region are generally <0.005 mg L-1. There was no spatial association between As concentrations in ground water and proximity to orchards. Arsenic had limited mobility into ground water from surface soils contaminated with arsenical pesticide residues at concentrations typically found in orchards.

Journal of Environmental Quality↗