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USGS2013

Challenge theme 2: assuring water availability and quality in the 21st century: Chapter 4 in United States-Mexican Borderlands: Facing tomorrow's challenges through USGS science

Along the United States–Mexican border, the health of communities, economies, and ecosystems is inextricably intertwined with the availability and quality of water, but effective water management in the Borderlands is complicated. Water users compete for resources, and their needs are increasing. Managers are faced with issues such as finding a balance between agriculture and rapidly growing cities or maintaining public supplies while ensuring sufficient resources for aquatic ecosystems. In addition to human factors, the dry climate of the Borderlands, as compared to more temperate regions, also increases the challenge of balancing water supplies between humans and ecosystems. Warmer, drier, and more variable conditions across the southwestern United States—the projected results of climate change (Seager and others, 2007)—would further stress water supplies.

United States-Mexico Borderlands↗

USGS2003

Hazards, Disasters, and The National Map

Governments depend on base geographic information that describes the Earth's surface and locates features. They use this information for economic and community development, land and natural resource management, delivery of health services, and ensuring public safety. It is also the foundation for studying and solving geographically based problems. Geographic information underpins an increasingly large part of the Nation's economy. It is an important part of our national infrastructure in the same way that the Interstate Highway System is an essential element of our transportation network. Federal, State, and local response and management personnel must have current, reliable, and easily accessible geographic information and maps to prepare for, respond to, or recover from emergency situations. In life-threatening events, such as earthquakes, floods, or wildland fires, geographic information is essential for locating critical infrastructure and carrying out evacuation and rescue operations.

Fact Sheet↗

USGS2014

The quality of our Nation's waters: Water quality in the Denver Basin aquifer system, Colorado, 2003-05

Availability and sustainability of groundwater in the Denver Basin aquifer system depend on water quantity and water quality. The Denver Basin aquifer system underlies about 7,000 square miles of the Great Plains in eastern Colorado and is the primary or sole source of water for domestic and public supply in many areas of the basin. Use of groundwater from the Denver Basin sandstone aquifers has been instrumental for development of the south Denver metropolitan area and other areas, but has resulted in a decline in water levels in some parts of the system. Human activities in many areas have adversely affected the quality of water in the aquifer system, especially the shallow parts. Groundwater in deeper parts of the system used for drinking water, once considered isolated from the effects of overlying land use, is increasingly vulnerable to contamination from human activities and geologic materials. Availability and sustainability of high-quality groundwater are vital to the economic health of the Denver Basin area.

Colorado↗

USGS2013

Water-quality and related aquatic biological characterization of Fish Creek, Teton County, Wyoming, 2007-2011

Fish Creek, in western Wyoming near the town of Wilson, is a key feature in the area because it is used for irrigation, fishing, and other recreation, and adds scenic value to properties it runs through. Public concern about nuisance growths of aquatic plants in Fish Creek has been increasing since the early 2000s. To address these concerns, the U.S. Geological Survey, in cooperation with the Teton Conservation District, began studying Fish Creek in 2004 to describe the hydrology of the stream and later (2007–11) to characterize the water quality and the biological communities. In particular, the study was designed to address three specific questions: •Is algal growth in Fish Creek typical for a stream of its size and geographic area? •Are nutrients entering Fish Creek from nearby land use? •What is the quality of the water in Fish Creek and the health of its biological communities?

Wyoming↗

USGS2012

Estimated probability of arsenic in groundwater from bedrock aquifers in New Hampshire, 2011

Probabilities of arsenic occurrence in groundwater from bedrock aquifers at concentrations of 1, 5, and 10 micrograms per liter (µg/L) were estimated during 2011 using multivariate logistic regression. These estimates were developed for use by the New Hampshire Environmental Public Health Tracking Program. About 39 percent of New Hampshire bedrock groundwater was identified as having at least a 50 percent chance of containing an arsenic concentration greater than or equal to 1 µg/L. This compares to about 7 percent of New Hampshire bedrock groundwater having at least a 50 percent chance of containing an arsenic concentration equaling or exceeding 5 µg/L and about 5 percent of the State having at least a 50 percent chance for its bedrock groundwater to contain concentrations at or above 10 µg/L. The southeastern counties of Merrimack, Strafford, Hillsborough, and Rockingham have the greatest potential for having arsenic concentrations above 5 and 10 µg/L in bedrock groundwater. Significant predictors of arsenic in groundwater from bedrock aquifers for all three thresholds analyzed included geologic, geochemical, land use, hydrologic, topographic, and demographic factors. Among the three thresholds evaluated, there were some differences in explanatory variables, but many variables were the same. More than 250 individual predictor variables were assembled for this study and tested as potential predictor variables for the models. More than 1,700 individual measurements of arsenic concentration from a combination of public and private water-supply wells served as the dependent (or predicted) variable in the models. The statewide maps generated by the probability models are not designed to predict arsenic concentration in any single well, but they are expected to provide useful information in areas of the State that currently contain little to no data on arsenic concentration. They also may aid in resource decision making, in determining potential risk for private wells, and in ecological-level analysis of disease outcomes. The approach for modeling arsenic in groundwater could also be applied to other environmental contaminants that have potential implications for human health, such as uranium, radon, fluoride, manganese, volatile organic compounds, nitrate, and bacteria.

New Hampshire↗

USGS2013

Groundwater-quality data in the Cascade Range and Modoc Plateau study unit, 2010-Results from the California GAMA Program

Groundwater quality in the 39,000-square-kilometer Cascade Range and Modoc Plateau (CAMP) study unit was investigated by the U.S. Geological Survey (USGS) from July through October 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The CAMP study unit is the thirty-second study unit to be sampled as part of the GAMA PBP. The GAMA CAMP study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system and to facilitate statistically consistent comparisons of untreated-groundwater quality throughout California. The primary aquifer system is defined as that part of the aquifer corresponding to the open or screened intervals of wells listed in the California Department of Public Health (CDPH) database for the CAMP study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from the quality of groundwater in the primary aquifer system; shallow groundwater may be more vulnerable to surficial contamination. In the CAMP study unit, groundwater samples were collected from 90 wells and springs in 6 study areas (Sacramento Valley Eastside, Honey Lake Valley, Cascade Range and Modoc Plateau Low Use Basins, Shasta Valley and Mount Shasta Volcanic Area, Quaternary Volcanic Areas, and Tertiary Volcanic Areas) in Butte, Lassen, Modoc, Plumas, Shasta, Siskiyou, and Tehama Counties. Wells and springs were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells). Groundwater samples were analyzed for field water-quality indicators, organic constituents, perchlorate, inorganic constituents, radioactive constituents, and microbial indicators. Naturally occurring isotopes and dissolved noble gases also were measured to provide a dataset that will be used to help interpret the sources and ages of the sampled groundwater in subsequent reports. In total, 221 constituents were investigated for this study. Three types of quality-control samples (blanks, replicates, and matrix spikes) were collected at approximately 10 percent of the wells in the CAMP study unit, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Blanks rarely contained detectable concentrations of any constituent, suggesting that contamination from sample collection procedures was not a significant source of bias in the data for the groundwater samples. Replicate samples generally were within the limits of acceptable analytical reproducibility. Matrix-spike recoveries were within the acceptable range (70 to 130 percent) for approximately 90 percent of the compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, untreated groundwater typically is treated, disinfected, and (or) blended with other waters to maintain water quality. Regulatory benchmarks apply to water that is served to the consumer, not to untreated groundwater. However, to provide some context for the results, concentrations of constituents measured in the untreated groundwater were compared with regulatory and non-regulatory health-based benchmarks established by the U.S. Environmental Protection Agency (USEPA) and CDPH, and to non-regulatory benchmarks established for aesthetic concerns by CDPH. Comparisons between data collected for this study and benchmarks for drinking water are for illustrative purposes only and are not indicative of compliance or non-compliance with those benchmarks. All organic constituents and most inorganic constituents that were detected in groundwater samples from the 90 grid wells in the CAMP study unit were detected at concentrations less than drinking-water benchmarks. Of the 148 organic constituents analyzed, 27 were detected in groundwater samples; concentrations of all detected constituents were less than regulatory and nonregulatory health-based benchmarks, and all were less than 1/10 of benchmark levels. One or more organic constituents were detected in 52 percent of the grid wells in the CAMP study unit: VOCs were detected in 30 percent, and pesticides and pesticide degradates were detected in 31 percent. Trace elements, major ions, nutrients, and radioactive constituents were sampled for at 90 grid wells in the CAMP study unit, and most detected concentrations were less than health-based benchmarks. Exceptions include three detections of arsenic greater than the USEPA maximum contaminant level (MCL-US) of 10 micrograms per liter (µg/L), two detections of boron greater than the CDPH notification level (NL-CA) of 1,000 µg/L, two detections of molybdenum greater than the USEPA lifetime health advisory level (HAL-US) of 40 µg/L, two detections of vanadium greater than the CDPH notification level (NL-CA) of 50 µg/L, one detection of nitrate, as nitrogen, greater than the MCL-US of 10 milligrams per liter (mg/L), two detections of uranium greater than the MCL-US of 30 µg/L and the MCL-CA of 20 picocuries per liter (pCi/L), one detection of radon-222 greater than the proposed MCL-US of 4,000 pCi/L, and two detections of gross alpha particle activity greater than the MCL-US of 15 pCi/L. Results for inorganic constituents with non-regulatory benchmarks set for aesthetic concerns showed that iron concentrations greater than the CDPH secondary maximum contaminant level (SMCL-CA) of 300 µg/L were detected in four grid wells. Manganese concentrations greater than the SMCL-CA of 50 µg/L were detected in nine grid wells. Chloride and TDS were detected at concentrations greater than the upper SMCL-CA benchmarks of 500 mg/L and 1,000 mg/L, respectively, in one grid well. Microbial indicators (total coliform and Escherichia coli [E. coli]) were detected in 11 percent of the 83 grid wells sampled for these analyses in the CAMP study unit. The presence of total coliform was detected in nine grid wells, and the presence of E. coli was detected in one of these same grid wells.

California↗

USGS2002

Data on occurrence of selected trace metals, organochlorines, and semivolatile organic compounds in edible fish tissues from Lake Worth, Fort Worth, Texas, 1999

A public-health assessment conducted for the Texas Department of Health and the Agency for Toxic Substances and Disease Registry concluded that exposure to contaminants through the aquatic food chain is an indeterminate human-health hazard in Lake Worth, Fort Worth, Texas. In 1999, the U.S. Geological Survey, in cooperation with the U.S. Air Force and in collaboration with the Texas Department of Health, collected samples of edible fish tissues from Lake Worth for analysis of selected trace metals, organochlorines, and semivolatile organic compounds to support a human-health risk assessment. Left-side, skin-off fillet samples were collected from 10 individuals each of channel catfish, common carp, freshwater drum (gaspergou), largemouth bass, and white crappie but only from five smallmouth buffalo. The U.S. Geological Survey National Water Quality Laboratory analyzed the samples for 22 trace metals, 40 organochlorine pesticides and polychlorinated biphenyls, and 75 semivolatile organic compounds.

Texas↗

USGS2007

The National Map - Orthoimagery Layer

Many Federal, State, and local agencies use a common set of framework geographic information databases as a tool for economic and community development, land and natural resource management, and health and safety services. Emergency management and homeland security applications rely on this information. Private industry, nongovernmental organizations, and individual citizens use the same geographic data. Geographic information underpins an increasingly large part of the Nation's economy. The U.S. Geological Survey (USGS) is developing The National Map to be a seamless, continually maintained, and nationally consistent set of online, public domain, framework geographic information databases. The National Map will serve as a foundation for integrating, sharing, and using data easily and consistently. The data will be the source of revised paper topographic maps. The National Map includes digital orthorectified imagery; elevation data; vector data for hydrography, transportation, boundary, and structure features; geographic names; and land cover information.

Fact Sheet↗

USGS2012

Lake water quality: Chapter 4 in A synthesis of aquatic science for management of Lakes Mead and Mohave

Given the importance of the availability and quality of water in Lake Mead, it has become one of the most intensely sampled and studied bodies of water in the United States. As a result, data are available from sampling stations across the lake (fig. 4-1 and see U.S. Geological Survey Automated Water-Quality Platforms) to provide information on past and current (2012) water-quality conditions and on invasive species that influence—and are affected by—water quality. Water quality in Lakes Mead and Mohave generally exceeds standards set by the State of Nevada to protect water supplies for public uses: drinking water, aquatic ecosystem health, recreation, or agricultural irrigation. In comparison to other reservoirs studied by the U.S. Environmental Protection Agency (USEPA) for a national lake assessment (U.S. Environmental Protection Agency, 2010), Lake Mead is well within the highest or ‘good’ category for recreation and aquatic health (see U.S. Environmental Protection Agency National Lakes Assessment and Lake Mead for more details). While a small part of the lake, particularly Las Vegas Bay, is locally influenced by runoff from urbanized tributaries such as Las Vegas Wash, contaminant loading in the lake as a whole is low compared to other reservoirs in the nation, which are influenced by runoff from more heavily urbanized watersheds (Rosen and Van Metre, 2010).

Circular↗

USGS2004

Hydrogeologic characteristics of four public drinking-water supply springs in northern Arkansas

In October 2000, a study was undertaken by the U.S. Geological Survey (USGS) in cooperation with the Arkansas Department of Health to determine the hydrogeologic characteristics, including the extent of the recharge areas, for Hughes Spring, Stark Spring, Evening Shade Spring, and Roaring Spring, which are used for public-water supply in northern Arkansas. Information pertaining to each spring can be used to enable development of effective management plans to protect these water resources and public health. An integrated approach to determine the ground-water characteristics and the extent of the local recharge areas of the four springs incorporated tools and methods of hydrology, structural geology, geomorphology, geophysics, and geochemistry. Analyses of discharge, temperature, and water quality were completed to describe ground-water flow characteristics, source-water characteristics, and connectivity of the ground-water system with surface runoff. Water-level contour maps were constructed to determine ground-water flow directions and ground-water tracer tests were conducted to determine the extent of the recharge areas and ground-water flow velocities. Hughes Spring supplies water for the city of Marshall, Arkansas, and the surrounding area. The mean annual discharge for Hughes Spring was 2.9 and 5.2 cubic feet per second for water years 2001 and 2002, respectively. Recharge to the spring occurs mainly from the Boone Formation (Springfield Plateau aquifer). Ground-water tracer tests indicate the recharge area for Hughes Spring generally coincides with the surface drainage area (15.8 square miles) and that Hughes Spring is connected directly to the surface flow in Brush Creek. The geochemistry of Hughes Spring demonstrated variations with flow conditions and the influence of surface-runoff in the recharge area. Calcite saturation indices, total dissolved solids concentrations, and hardness demonstrate noticeable differences with flow conditions reflecting the reduced residence time and interaction of water with the source rock within the ground-water system at higher discharges for Hughes Spring. Concentrations of fecal indicator bacteria also demonstrated a substantial increase during high-flow conditions, suggesting that a non-point source of bacteria possibly from livestock may enter the system. Conversely, nutrient concentrations did not vary with flow and were similar to concentrations reported for undeveloped sites in the Springfield Plateau and Ozark aquifers in northern Arkansas and southern Missouri. Deuterium and oxygen-18 data show that the Hughes Spring discharge is representative of direct precipitation and not influenced by water enriched in oxygen-18 through evaporation. Discharge data show that Hughes Spring is dominated by conduit type ground-water flow, but a considerable component of diffuse flow also exists in the ground-water system. Carbon-13 data indicate a substantial component of the recharge water interacts with the surface material (soil and regolith) in the recharge area before entering the ground-water system for Hughes Spring. Tritium data for Hughes Spring indicate that the discharge water is a mixture of recent recharge and sub-modern water (recharged prior to 1952). Stark Spring supplies water for the city of Cushman, Arkansas, and the surrounding area. 2 Hydrogeologic Characteristics of Four Public Drinking-Water Supply Springs in Northern Arkansas The mean annual discharge for Stark Spring was 0.5 and 1.5 cubic feet per second for water years 2001 and 2002, respectively. The discharge and water-quality data show the ground-water system for Stark Spring is dominated by rapid recharge from surface runoff and mainly consists of a conduit- type flow system with little diffuse-type flow. Analyses of discharge data show that the estimated recharge area (0.79 square mile) is larger than the surface drainage area (0.34 square mile). Ground-water tracer tests and the outcrop of the

Water-Resources Investigations Report↗

USGS2012

Status of groundwater quality in the San Fernando--San Gabriel study unit, 2005--California GAMA Priority Basin Project

Groundwater quality in the approximately 460-square-mile San Fernando--San Gabriel (FG) study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study area is in Los Angeles County and includes Tertiary-Quaternary sedimentary basins situated within the Transverse Ranges of southern California. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA FG study was designed to provide a spatially unbiased assessment of the quality of untreated (raw) groundwater in the primary aquifer systems (hereinafter referred to as primary aquifers) throughout California. The assessment is based on water-quality and ancillary data collected in 2005 by the USGS from 35 wells and on water-quality data from the California Department of Public Health (CDPH) database. The primary aquifers were defined by the depth interval of the wells listed in the CDPH database for the FG study unit. The quality of groundwater in primary aquifers may be different from that in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. This study assesses the status of the current quality of the groundwater resource by using data from samples analyzed for volatile organic compounds (VOCs), pesticides, and naturally occurring inorganic constituents, such as major ions and trace elements. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifers of the FG study unit, not the treated drinking water delivered to consumers by water purveyors.

California↗

USGS2024

Assessment of per- and polyfluoroalkyl substances in water resources of New Mexico, 2020–21

Per- and polyfluoroalkyl substances (PFAS) have been detected in public and private drinking-water wells, springs, and surface waters in New Mexico; however, the presence and distribution of PFAS in water resources across the State are not well characterized. From August 2020 to October 2021, the U.S. Geological Survey, in cooperation with the New Mexico Environment Department, collected water-quality samples from groundwater and surface-water sites throughout New Mexico. One hundred and seventeen groundwater wells were sampled from unconfined water-table aquifers for PFAS and a geochemical suite including major ions, trace elements, nutrients, dissolved organic carbon (DOC), stable isotopes of oxygen and hydrogen, tritium, and carbon-14 to provide context for groundwater age and geochemical evolution. Eighteen surface-water samples were analyzed for PFAS, and select samples were analyzed for wastewater tracers, major ions, trace elements, and DOC. Blanks and replicates indicated low bias and variability for PFAS, wastewater tracers, and geochemical compounds. Twenty-seven of the 117 groundwater sites had PFAS concentrations reported above the detection level, and there were no exceedances of the 2016 U.S. Environmental Protection Agency health advisory of 70 nanograms per liter (ng/L) perfluorooctanoic acid plus perfluorooctane sulfonic acid. Twenty-two sites were resampled and showed similar signatures, excluding some springs. Total PFAS concentrations ranged from 0.91 to 80.3 ng/L. The most frequently detected PFAS at groundwater sites were perfluorobutanesulfonic acid (PFBS; 11 sites), perfluoropentanoic acid (10 sites), and perfluorohexanoic acid (9 sites). Correlations were found between certain PFAS compounds that suggest similar sources. PFAS were also correlated with tritium, DOC, and nitrate, which indicated that a presence of anthropogenic compounds could in turn indicate a likelihood of PFAS occurrence. In addition, a cluster analysis showed that varying geochemical processes and sources of anthropogenic compounds likely contribute to the PFAS signature of each groundwater sample. Surface-water samples showed variable total PFAS concentrations ranging from 1.0 to 155.4 ng/L. Sites downstream from urban areas showed numerous PFAS detections. Some undeveloped areas where minimal PFAS detections would be expected had PFAS detections. Correlations between PFAS were found that suggested similar sources. Perfluoropentanoic acid and PFBS were the most frequently detected PFAS, and PFBS had the highest single concentration of 93 ng/L. Results of the study provide an overview of PFAS occurrences in the water resources of New Mexico along with geochemical context and are used to identify areas for further scientific investigations that could further characterize PFAS occurrences in New Mexico.

New Mexico↗

USGS2010

Understanding beach health throughout the Great Lakes-Entering a new era of investigations

For over a decade, the U.S. Geological Survey (USGS) has been a leader in the science of beach health. The overall mission of this work is to provide science-based information and methods that will allow beach managers to more accurately make beach closure and advisory decisions, understand the sources and physical processes affecting beach contaminants, and understand how science-based information can be used to mitigate and restore beaches and protect the public. The work consists of four science elements-real-time assessments; pathogens and microbial source tracking; coastal processes; and data analysis, interpretation, and communication - which are described in this fact sheet. Some of the key questions for USGS beach research are the following: Are there better ways to inform the public whether they can use a beach without risking their health? How do new rapid analytical methods compare to traditional methods for determining concentrations of fecal-indicator bacteria at beaches? Are pathogens present at beaches and, if so, how do they get to the beach, and what is their source? How do sand movement and wave action on the beach affect fecal-indicator-bacteria and pathogen concentrations in the lake water? What are the best indicators of pathogenic microorganisms? With so many potential sources of fecal contamination at a beach, what methods can be used to distinguish the contributions from humans? What characteristics of beaches contribute most to influencing bacterial indicator and pathogen concentrations in beach sands and groundwater?

Fact Sheet↗

USGS2012

Data resources for range-wide assessment of livestock grazing across the sagebrush biome

The data contained in this series were compiled, modified, and analyzed for the U.S. Geological Survey (USGS) report "Range-Wide Assessment of Livestock Grazing Across the Sagebrush Biome." This report can be accessed through the USGS Publications Warehouse (online linkage: http://pubs.usgs.gov/of/2011/1263/). The dataset contains spatial and tabular data related to Bureau of Land Management (BLM) Grazing Allotments. We reviewed the BLM national grazing allotment spatial dataset available from the GeoCommunicator National Integrated Land System (NILS) website in 2007 (http://www.geocommunicator.gov). We identified several limitations in those data and learned that some BLM State and/or field offices had updated their spatial data to rectify these limitations, but maintained the data outside of NILS. We contacted appropriate BLM offices (State or field, 25 in all) to obtain the most recent data, assessed the data, established a data development protocol, and compiled data into a topologically enforced dataset throughout the area of interest for this project (that is, the pre-settlement distribution of Greater Sage-Grouse in the Western United States). The final database includes three spatial datasets: Allotments (BLM Grazing Allotments), OUT_Polygons (nonallotment polygons used to ensure topology), and Duplicate_Polygon_Allotments. See Appendix 1 of the aforementioned report for complete methods. The tabular data presented here consists of information synthesized by the Land Health Standard (LHS) analysis (Appendix 2), and data obtained from the BLM Rangeland Administration System (http://www.blm.gov/ras/). In 2008, available LHS data for all allotments in all regions were compiled by BLM in response to a Freedom of Information Act (FOIA) request made by a private organization. The BLM provided us with a copy of these data. These data provided three major types of information that were of interest: (1) date(s) (if any) of the most recent LHS evaluation for each allotment; (2) whether if evaluated, each region-specific standard (3–8 LHS depending on region) had been met on a given allotment; and (3) whether livestock contributed to any of these standards not being met. A description of how we processed the original data to prepare for analysis is described in Appendix 2, and the synthesized dataset can be found in the table "lhs_x_walk." Permitted use dates, livestock type (horse, sheep or cattle), number of livestock, and Animal Unit Months [the number of animal units (1,000-pound animal equivalents) that can be grazed for 31 days with the available forage in a sustainable manner] are the legal maximum grazing amounts for a given allotment, and legal adjustments to these numbers occur infrequently. We summarized permitted use by BLM allotment in the table "Permitted_Use." Billed use records are used for calculations of permittees' annual grazing bills. We summarized billed use by allotment for BLM grazing year in the table "Billed_Use." All three tables can be joined with the allotment spatial data in a geographic information system (GIS) environment, using the IDENT attribute as the primary key.

Data Series↗

USGS2017

Design and methods of the Pacific Northwest Stream Quality Assessment (PNSQA), 2015

In 2015, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project conducted the Pacific Northwest Stream Quality Assessment (PNSQA) to investigate stream quality across the western part of the Pacific Northwest. The goal of the PNSQA was to assess the health of streams in the region by characterizing multiple water-quality factors that are stressors to in-stream aquatic life and by evaluating the relation between these stressors and the condition of biological communities. The effects of urbanization and agriculture on stream quality for the Puget Lowland and Willamette Valley Level III Ecoregions were the focus of this regional study. Findings will help inform the public and policymakers about human and environmental factors that are the most critical in affecting stream quality and, thus, provide insights into possible strategies to protect or improve the health of streams in the region. Land-use data were used in the study to identify and select sites within the region that ranged in levels of urban and agricultural development. A total of 88 sites were selected across the region—69 were on streams that explicitly spanned a range of urban land use in their watersheds, 8 were on streams in agricultural watersheds, and 11 were reference sites with little or no development in their watersheds. Depending on the type of land use, sites were sampled for contaminants, nutrients, and sediment for either a 4- or 10-week period during April, May, and June 2015. This water-quality “index period” was immediately followed with an ecological survey of all sites that included stream habitat, benthic algae, benthic macroinvertebrates, and fish. Additionally, streambed sediment was collected during the ecological survey for analysis of sediment chemistry and toxicity testing. This report provides a detailed description of the specific study components and methods of the PNSQA, including (1) surveys of stream habitat and aquatic biota, (2) discrete water sampling, (3) deployment of passive polar organic chemical integrative samplers for pesticides and pharmaceuticals, and (4) sampling of streambed sediment. At selected study sites, toxicity testing of streambed sediment, continuous water-quality monitoring, and daily pesticide sampling also were conducted and are described.

Oregon, Washington↗

USGS2014

Arsenic, iron, lead, manganese, and uranium concentrations in private bedrock wells in southeastern New Hampshire, 2012-2013

Trace metals, such as arsenic, iron, lead, manganese, and uranium, in groundwater used for drinking have long been a concern because of the potential adverse effects on human health and the aesthetic or nuisance problems that some present. Moderate to high concentrations of the trace metal arsenic have been identified in drinking water from groundwater sources in southeastern New Hampshire, a rapidly growing region of the State (Montgomery and others, 2003). During the past decade (2000–10), southeastern New Hampshire, which is composed of Hillsborough, Rockingham, and Strafford Counties, has grown in population by nearly 48,700 (or 6.4 percent) to 819,100. These three counties contain 62 percent of the State’s population but encompass only about 22 percent of the land area (New Hampshire Office of Energy and Planning, 2011). According to a 2005 water-use study (Hayes and Horn, 2009), about 39 percent of the population in these three counties in southeastern New Hampshire uses private wells as sources of drinking water, and these wells are not required by the State to be routinely tested for trace metals or other contaminants. Some trace metals have associated human-health benchmarks or nonhealth guidelines that have been established by the U.S. Environmental Protection Agency (EPA) to regulate public water supplies. The EPA has established a maximum contaminant level (MCL) of 10 micrograms per liter (μg/L) for arsenic (As) and a MCL of 30 μg/L for uranium (U) because of associated health risks (U.S. Environmental Protection Agency, 2012). Iron (Fe) and manganese (Mn) are essential for human health, but Mn at high doses may have adverse cognitive effects in children (Bouchard and others, 2011; Agency for Toxic Substances and Disease Registry, 2012); therefore, the EPA has issued a lifetime health advisory (LHA) of 300 μg/L for Mn. Recommended secondary maximum contaminant levels (SMCLs) for Fe (300 μg/L) and Mn (50 μg/L) were established primarily as nonhealth guidelines—based on aesthetic considerations, such as taste or the staining of laundry and plumbing fixtures—because these contaminants, at the SMCLs, are not considered to present risks to human health. Because lead (Pb) contamination of drinking water typically results from corrosion of plumbing materials belonging to water-system customers but still poses a risk to human health, the EPA established an action level (AL) of 15 μg/L for Pb instead of an MCL or SMCL (U.S. Environmental Protection Agency, 2012). The 15-μg/L AL for Pb has been adopted by the New Hampshire Department of Environmental Services for public water systems, and if exceeded, the public water system must inform their customers and undertake additional actions to control corrosion in the pipes of the distribution system (New Hampshire Department of Environmental Services, 2013). Unlike the quality of drinking water provided by public water suppliers, the quality of drinking water obtained from private wells in New Hampshire is not regulated; consequently, private wells are sampled only when individual well owners voluntarily choose to sample them. The U.S. Geological Survey (USGS), in cooperation with the EPA New England, conducted an assessment in 2012–13 to provide private well owners and State and Federal health officials with information on the distribution of trace-metal (As, Fe, Pb, Mn, and U) concentrations in groundwater from bedrock aquifers in the three counties of southeastern New Hampshire. This fact sheet analyzes data from water samples collected by a randomly selected group of private well owners from the three-county study area and describes the major findings for trace-metal concentrations.

New Hampshire↗

USGS2024

Characterizing the areal extent of PFAS contamination in fish species downgradient of AFFF source zones

Most monitoring programs next to large per- and polyfluoroalkyl substances (PFAS) sources focus on drinking water contamination near source zones. However, less is understood about how these sources affect downgradient hydrological systems and food webs. Here, we report paired PFAS measurements in water, sediment, and aquatic biota along a hydrological gradient away from source zones contaminated by the use of legacy aqueous film-forming foam (AFFF) manufactured using electrochemical fluorination. Clustering analysis indicates that the PFAS composition characteristic of AFFF is detectable in water and fishes >8 km from the source. Concentrations of 38 targeted PFAS and extractable organofluorine (EOF) decreased in fishes downgradient of the AFFF-contaminated source zones. However, PFAS concentrations remained above consumption limits at all locations within the affected watershed. Perfluoroalkyl sulfonamide precursors accounted for approximately half of targeted PFAS in fish tissues, which explain >90% of EOF across all sampling locations. Suspect screening analyses revealed the presence of a polyfluoroketone pharmaceutical in fish species, and a fluorinated agrochemical in water that likely does not accumulate in biological tissues, suggesting the presence of diffuse sources such as septic system and agrochemical inputs throughout the watershed in addition to AFFF contamination. Based on these results, monitoring programs that consider all hydrologically connected regions within watersheds affected by large PFAS sources would help ensure public health protection.

Massachusetts↗

USGS2006

Volatile organic compounds in samples from domestic and public wells, 1985-2002

The U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program recently completed a national study of volatile organic compounds (VOCs) in the Nation's ground water (Zogorski and others, 2006). Part of this assessment emphasizes the occurrence of 55 VOCs in samples from 2,401 domestic wells and 1,096 public wells during 1985-2002. Samples were collected prior to any treatment or blending of water. Domestic wells are privately owned, self-supplied sources used for drinking water and household use (Moran and others, 2002). Public wells are privately or publicly owned and supply water to public water systems (PWSs). Samples from public wells in this assessment characterize the quality of water captured by wells that supply drinking water to PWSs. These systems supply drinking water to at least 15 service connections or regularly serve at least 25 individuals daily at least 60 days a year (U.S. Environmental Protection Agency, 2005). For a screening-level assessment, VOC concentrations were compared to human-health benchmarks. Concentrations greater than the U.S. Environmental Protection Agency's (USEPA) Maximum Contamination Levels (MCLs) (U.S. Environmental Protection Agency, 2004) or the USGS's Health-Based Screening Levels (HBSLs) (Zogorski and others, 2006) were considered of potential human-health concern. The findings from the well samples provide an important perspective on the quality of the Nation's ground water used for drinking-water supplies. More information about this national assessment of VOCs is available (http://water.usgs.gov/nawqa/vocs/national_assessment).

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