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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↗

Amphibian occurrence and aquatic invaders in a changing landscape: Implications for wetland mitigation in the Willamette Valley, Oregon

Despite concern about the conservation status of amphibians in western North America, few field studies have documented occurrence patterns of amphibians relative to potential stressors. We surveyed wetland fauna in Oregon's Willamette Valley and used an information theoretic approach (AIC) to rank the associations between native amphibian breeding occurrence and wetland characteristics, non-native aquatic predators, and landscape characteristics in a mixed urban-agricultural landscape. Best predictors varied among the five native amphibians and were generally consistent with life history differences. Pacific tree frog (Pseudacris regilla) and long-toed salamander (Ambystoma macrodactylum) occurrence was best predicted by the absence of non-native fish. Northern red-legged frog (Rana a. aurora) and northwestern salamander (Ambystoma gracile) were most strongly related to wetland vegetative characteristics. The occurrence of rough-skinned newts (Taricha granulosa), a migratory species that makes extensive use of terrestrial habitats, was best predicted by greater forest cover within 1 km. The absence of non-native fish was a strong predictor of occurrence for four of the five native species. In contrast, amphibians were not strongly related to native fish presence. We found little evidence supporting negative effects of the presence of breeding populations of bullfrog (Rana catesbeiana) on any native species. Only the two Ambystoma salamanders were associated with wetland permanence. Northwestern salamanders (which usually have a multi-year larval stage) were associated with permanent waters, while long-toed salamanders were associated with temporary wetlands. Although all the species make some use of upland habitats, only one (rough-skinned newt) was strongly associated with surrounding landscape conditions. Instead, our analysis suggests that within-wetland characteristics best predict amphibian occurrence in this region. We recommend that wetland preservation and mitigation efforts concentrate on sites lacking non-native fish for the conservation of native amphibians in the Willamette Valley and other western lowlands.

Wetlands↗

Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants and their effects on fish in the Mississippi River Basin

We collected, examined, and analyzed 1378 fish of 22 species from 47 sites in the Mississippi River basin (MRB) during 1995 and from a reference site in 1996. The sampling sites in the MRB represented National Contaminant Biomonitoring Program (NCBP) stations situated at key points on major rivers and National Water- Quality Assessment Program (NAWQA) stations located on lower-order rivers and streams in the Eastern Iowa Basins (EIB) and Mississippi Embayment (MSE) Study Units. The reference site was the water supply system of the USGS-Leetown Science Center in rural Jefferson County, WV. Common carp (Cyprinus carpio; carp) and black basses (Micropterus spp.; bass), the targeted species, together represented 82% of the fish collected. Each fish was examined in the field for externally and internally visible gross lesions, selected organs were weighed to compute various ponderal and organo-somatic indices, and selected tissues and fluids were obtained and preserved for analysis of biomarkers. Fish health indicators included splenic macrophage aggregates, lysozyme activity, and hispathological analysis of liver, kidney, and other tissues. Reproductive biomarkers included analysis of plasma concentrations of vitellogenin (vtg) and the sex steroid hormones 17-estradiol (E2) and 11-ketotestosterone (11- kt); and the histological determination of percent oocyte atresia (in female fish) and gonadal stage. Hepatic ethoxyresorufin O-deethylase (EROD) activity was also measured. Composite samples of whole fish from each station were grouped by species and gender and analyzed for persistent organochlorine and elemental contaminants and for dioxin-like activity (TCDD-EQ) using the H4IIE rat hepatoma cell bioassay. Organochlorine and inorganic contaminant concentrations in fish were generally low relative to historical levels at most sites, but remained present at concentrations representing threats to piscivorous wildlife in some locations. Toxaphene and DDT (mostly as p,p?-DDE) concentrations remained elevated in fish from the cottongrowing regions of the lower Mississippi valley, and were generally greater in the smaller streams draining agricultural areas (that is, in the MSE Study Unit) than at large river sites. Cyclodiene pesticide concentrations were also greatest in the EIB Study Unit and elsewhere in the corn-growing regions of the mid-MRB. Former point-sources of organochlorine pesticides also remained evident, especially in the Mississippi River near Memphis, TN. Consistent with previous findings, total PCB concentrations tended to be greatest (1-3 g/g) in the industrialized and urbanized Ohio River and Upper Mississippi sub-basins and at Memphis, TN, and were generally correlated with TCDD-EQ and EROD activity. Conversely, PCB concentrations were low (<0.1 g/g) in the more agricultural parts of the MRB. Concentrations of inorganic contaminants were also relatively low and stable or declining relative to past levels at most sites. Exceptions were Hg and Se; Hg concentrations were slightly elevated (>0.3 g/g) in bass from the Mississippi River at Memphis and several other sites and in carp from one MSE site. Concentrations of Se were also great enough to constitute a hazard to piscivorous wildlife (>0.6 g/g) at several MRB sites in the western parts of the MRB and were especially high (4-5 g/g) in fish from John Martin Reservoir, CO, where elevated concentrations were reported previously. Biomarker results indicated that fish from many stations had been exposed to contaminants, but at no sites did findings indicate exposure to high concentrations of toxic chemicals. Noteworthy among biomarker findings was that 73% of the male smallmouth bass (Micropterus dolomieui) from the Mississippi River at Lake City, MN (Lake Pepin) were intersex as indicated by the histological detection of ovotestes; and the combined EROD and H4IIE results indicated that fish from several rural sites in the

Mississippi River basin↗

Storm runoff as related to urbanization in the Portland, Oregon-Vancouver, Washington Area

A series of equations was developed to provide a better method of determining flood frequencies in the Portland-Vancouver urban area than is now available. The resulting regression equations can be used to compute peak discharge and storm runoff with a standard error of estimate of approximately 30 percent. Basins used to define the regression equations ranged in size from 0.2 to 26 square miles. Those physical basin parameters that proved to be significant are: drainage area, effective impervious area, storage, rainfall intensity, basin slope, and soil infiltration. The equations indicate that total urbanization of an undeveloped basin can increase peak discharge as much as 3? times and almost double the volume of storm runoff. Impervious area, as delineated by mapping techniques, proved to be an inadequate physical parameter for use in the regression equations because builders and planners have devised many methods of routing storm runoff from impervious areas to the main channel (in effect, speeding up or slowing down the response to the storm). In some parts of the study area, storm runoff was diverted into dry wells and never entered the main channel. To define the effect of this rerouting, the digital model was used to find an effective impervious area that would 'best fit' the rainfall-runoff data. Field estimates to verify the effectiveness of the impervious area for two of the basins showed that optimizations were within 20 percent of those shown by the digital model. Users of these data who may find the effective impervious area a difficult, expensive, and time-consuming parameter to obtain have an alternative. The combination of land-use type I (parks, forests, and vacant lots) and Type II (agriculture) proved to be an excellent inverse indicator of impervious area. Land-use types I and II, coupled with the street-gutter density, an indication of effective routing, provide the user with alternative indices of urbanization.

Oregon, Washington↗

Geohydrology of Southeastern Pennsylvania

Rapid population growth in southeastern Pennsylvania has increased the demand for ground water. In an effort to address the increased ground-water needs, a ground-water investigation in a 5,200-square-mile area of southeastern Pennsylvania was initiated. Information on the geohydrologic system of the area and the water-bearing capabilities of 51 geohydrologic units in six physiographic provinces or sections (Coastal Plain, Piedmont Upland, Piedmont Lowland, Gettysburg-Newark Lowland, South Mountain, and Reading Prong) has been summarized. Also included are statistical summaries by geohydrologic unit for well construction and discharge data (according to water use), as well as inorganic and radiochemical ground-water-quality data. Characteristics of the ground-water-flow system in the study area, as well as aquifer hydrologic properties, are related to geology, but can be modified by human development. Ground-water flow in the Coastal Plain Physiographic Province, is through intergranular or primary openings under either unconfined or confined aquifer conditions. Historically, ground-water flowed toward the Delaware and Schuylkill Rivers, but the original flow paths and water quality have been altered significantly by urbanization. In igneous and metamorphic rocks (Piedmont Upland, South Mountain, and Reading Prong), ground-water flows through a network of interconnected secondary openings (fractures, joints, cleavage planes). Ground water in the carbonate rocks (Piedmont Lowland) also flows through a network of secondary openings, but these openings have been enlarged by solution. In the Triassic sedimentary rocks (Gettysburg-Newark Lowland), thin tabular aquifers are separated by much thicker, strata-bound aquitards. The fractured Triassic bedrock forms a very complex, anisotropic, and heterogeneous aquifer with horizontal permeability much greater than vertical permeability. In general, ground-water flow in southeastern Pennsylvania takes place within local flow systems that discharge within days or weeks to adjacent stream valleys or surface-water bodies. Intermediate (South Mountain) and regional (Gettysburg-Newark Lowland) scale systems, however, in which residence times have been measured in months or years discharge to major streams or rivers that are located in different physiographic provinces or sections or tens of miles distant. Well depths, casing lengths, reported yields, and specific capacities can vary significantly by geohydrologic unit, use of well, and topographic setting. Wells drilled in the Weverton and Loudon Formations, undivided, and the Montalto Quartzite Member (South Mountain) have median well and casing lengths of 374 and 130 feet, respectively, significantly greater than in almost every other geohydrologic unit in the study area. Wells drilled in the Peach Bottom Slate and Cardiff Conglomerate, undivided (Piedmont Upland) are typically shallow, with a median well depth of 90 feet. Wells in the Marburg Schist (Piedmont Upland) have the lowest median casing length—5.5 feet. Wells in the Stonehenge Formation (Piedmont Lowland), the most productive unit in the study area, have a median reported yield of 200 gallons per minute and a median specific capacity of 27 gallons per minute per foot. The Cocalico Formation (Piedmont Lowland) is the least productive unit with a median reported well yield of 2.5 gallons per minute and a median specific capacity of 0.01 gallons per minute per foot. In general, high-demand wells are significantly deeper, use significantly more casing, and have significantly greater yields than domestic wells drilled in the same unit. Commonly, wells drilled in valleys will have greater reported yields and specific capacities than wells drilled in the same unit on slopes or hilltops. Except where adversely affected by human activities, the quality of ground water in southeastern Pennsylvania is suitable for most purposes. Yet several water-quality criteria are exceeded in many wells throughout the area. Water from 51 percent of 2,075 wells sampled had a pH higher or lower than the range specified in the U.S. Environmental Protection Agency (USEPA) secondary maximum contaminant level (SMCL). Of water samples analyzed, about 1 percent of 1,623 wells contained concentrations of chloride and 27 percent of 1,624 wells sampled contained concentrations of iron that exceeded the USEPA SMCL. Twenty-seven percent of 1,397 wells sampled contained water with manganese concentrations greater than the USEPA SMCL. Sulfate concentrations in the water of 3 percent of 1,699 wells sampled and total dissolved solids in the water from 10 percent of 1,590 wells sampled exceeded the USEPA SMCL. Concentrations of cadmium, chromium, cyanide, mercury, nickel, radium-226, selenium, and zinc in the water exceeded the USEPA maximum contaminant level (MCL) in less than 5 percent of the 183 to 620 wells sampled. Nine percent of 625 wells sampled contained water with lead concentrations that exceeded the USEPA MCL. Radon concentrations in the water of 92 percent of the 285 wells sampled exceeded the proposed USEPA MCL. Radium-228 in the water of 10 percent of the 240 wells sampled and nitrate in the water of 13 percent of 1,413 wells sampled exceeded the USEPA MCL. Gross-alpha activity in the water was measured only in the Chickies and Harpers Formations of the Piedmont Upland, with 23 percent of the 168 wells sampled exceeding the USEPA MCL.

Water-Resources Investigations Report↗

Hydrogeology and shallow groundwater quality in the tidal Anacostia River watershed, Washington, D.C.

Groundwater hydrology and geochemistry within the tidal Anacostia River watershed of Washington, D.C. are related to natural and human influences. The U.S. Geological Survey, in cooperation with the District Department of Energy & Environment, began investigating the hydrogeology and groundwater quality of the watershed in 2002. Lithologic coring, groundwater-level and tidal monitoring, and water-quality sampling have been conducted to improve understanding of the groundwater-flow system, geochemistry, water quality, and the likely interaction between groundwater and the tidal Anacostia River. The flow and interaction of shallow groundwater with the tidal Anacostia River and other area streams are affected by diversions, pumping, land reclamation, and other human activities in this highly urbanized watershed. The tidal Anacostia River watershed is underlain by a wedge of unconsolidated sediments that is part of the Atlantic Coastal Plain Physiographic Province. These sediments form a system of confined and unconfined aquifers. The coarse sediments of the Potomac Group sand-dominated lithofacies form the Patuxent aquifer. The Patuxent aquifer crops out and subcrops in the northwestern part of the study area, but is confined to the southeast by the overlying Potomac Group clay-dominated lithofacies. Overlying the Potomac Group is a series of interbedded sands and clays that form an unconfined surficial aquifer system. Regional correlation in the unconfined surficial aquifer system is complicated by local heterogeneity in aquifer sediments. Local perched and semi-confined conditions occur in some areas. Recharge of the confined Patuxent aquifer occurs primarily in the outcrop and subcrop area, although some recharge may also occur through overlying confining units. Recharge to the unconfined surficial aquifer system occurs through infiltration of precipitation and possible artificial recharge from structures such as underground water or sewer pipes. In the Patuxent aquifer, hydraulic gradients indicate downward movement in the outcrop area, whereas hydraulic heads beneath the Anacostia River are higher than land surface, indicating an upward hydraulic gradient. In the unconfined surficial aquifer system, groundwater generally flows from upland recharge areas towards discharge areas near the Anacostia River and its tributaries. Groundwater from the confined part of the Patuxent aquifer also may discharge to the Anacostia River in locations where the overlying clay-dominated lithofacies of the Potomac Group is absent as a result of past geologic and (or) alluvial processes. Geochemistry and groundwater quality are affected by hydrologic conditions as well as anthropogenic influences. Local variability in groundwater quality reflects local variability in hydrogeologic conditions and sources of chemicals. Groundwater ranges from anoxic and iron- or calcium-bicarbonate type, to oxic with elevated nitrate. The occurrence and distribution of pesticides, volatile organic compounds, and other selected chemical compounds in groundwater reflect the multitude of sources common to urban areas, as well as variable hydrogeologic and geochemical conditions that affect their fate and transport in the environment. Overall, concentrations of only a few of the over 200 chemical constituents included in laboratory analyses exceeded regulatory standards or guidance values. These include tetrachloroethene and arsenic, which were each detected one time in different wells. There were also several detections of iron and manganese that exceeded regulatory standards or guidance values that are associated with reducing conditions in aquifer sediments.

Washington, D.C.↗

Quality of shallow ground water in areas of recent residential and commercial development, Wichita, Kansas, 2000

Water samples from 30 randomly distributed monitoring wells in areas of recent residential and commercial development (1960–96), Wichita, Kansas, were collected in 2000 as part of the High Plains Regional Ground-Water Study conducted by the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. The samples were analyzed for about 170 water-quality constituents that included chlorofluorocarbons, physical properties, dissolved solids and major ions, nutrients and dissolved organic carbon, trace elements, pesticide compounds, and volatile organic compounds. The purpose of this report is to provide an assessment of water quality in recharge to shallow ground water underlying areas of recent residential and commercial development and to determine the relation of ground-water quality to overlying urban land use. Analyses of water from the 30 monitoring wells for chlorofluorocarbons were used to estimate apparent dates of recharge. Water from 18 wells with nondegraded and uncontaminated chlorofluorocarbon concentrations had calculated apparent recharge dates that ranged from 1979 to 1990 with an average date of 1986. Water from 14 monitoring wells (47 percent) exceeded the 500-milligrams-per-liter Secondary Maximum Contaminant Level established by the U.S. Environmental Protection Agency for dissolved solids in drinking water. The Secondary Maximum Contaminant Levels of 250 milligrams per liter for chloride and sulfate were exceeded in water from one well. The source of the largest concentrations of dissolved solids and associated ions, such as chloride and sulfate, in shallow ground water in the study area probably is highly mineralized water moving out of the Arkansas River into the adjacent, unconsolidated deposits and mixing with the dominant calcium bicarbonate water in the deposits. Concentrations of most nutrients in water from the sampled wells were small, with the exception of nitrate. Although water from the sampled wells did not have nitrate concentrations larger than the 10-milligram-per-liter Maximum Contaminant Level for drinking water, water from 50 percent of the sampled wells showed nitrate enrichment (concentrations greater than 2.0 milligrams per liter). Most trace elements in water from the sampled wells were detected only in small concentrations, and few exceeded respective water-quality standards. Twenty percent of iron concentrations, 40 percent of manganese concentrations, 3 percent of arsenic concentrations, and 13 percent of uranium concentrations exceeded respective Maximum Contaminant Levels or Secondary Maximum Contaminant Levels. A total of 47 pesticide compounds were analyzed in ground-water samples during this study. Water from 73 percent of the wells sampled had detectable concentrations of one or more of 8 of these 47 compounds. The herbicide atrazine or its degradation product deethylatrazine were detected most frequently (in water from 70 percent of the sampled wells). Metolachlor was detected in water from 10 percent of the wells, and simazine was detected in water from 30 percent of the wells sampled. Other pesticides detected included dieldrin, pendimethalin, prometon, and tebuthiuron (each in water from 3 percent of the wells). All concentrations of these compounds were less than established Maximum Contaminant Levels. A total of 85 volatile organic compounds (VOCs) were analyzed in ground-water samples during this study. Water from 43 percent of the wells had a detectable concentration of one or more VOCs. Chloroform was the most frequently detected VOC (23 percent of the wells sampled).Seven other VOCs were detected in water at frequencies of 13 percent or less in the wells sampled. Concentrations of VOCs were less than respective Maximum Contaminant Levels, except one sample with a concentration of 9.0 micrograms per liter for tetrachloroethylene (Maximum Contaminant Level of 5.0 micrograms per liter). An analysis of hydraulic gradient, flow velocity, and residence time of the ground water indicated potential recharge areas that ranged from 0.8 to 2.8 miles upgradient of monitoring-well locations. Nineteen (63 percent) of these potential recharge areas were in agricultural areas or areas in transition from agricultural to residential and (or) commercial land use at the time water sampled from the monitoring wells was recharged to the shallow ground water. The occurrence of atrazine or deethylatrazine in water from 70 percent of the monitoring wells may indicate a historical agricultural land-use relation. This agricultural relation also may affect concentrations of other water-quality constituents of possible agricultural origin such as nitrate, which generally were in excess of background concentrations in shallow ground water.

Kansas↗

The hydrologic system of the south Florida peninsula—Development and application of the Biscayne and Southern Everglades Coastal Transport (BISECT) model

The Biscayne and Southern Everglades Coastal Transport (BISECT) model was developed by the U.S. Geological Survey under the Greater Everglades Priority Ecosystem Studies Initiative to evaluate, both separately and in conjunction, the likely effects on surface-water stages and flows, hydroperiod, and groundwater levels and salinity in south Florida of (1) a vertical Biscayne aquifer barrier to maintain higher wetland levels, (2) possible future changes to current water-management practices, and (3) sea-level rise. The BISECT model is a combination of the Tides and Inflows to the Mangrove Everglades (TIME) and Biscayne models of the western and eastern parts of south Florida including Everglades National Park, the southern Miami-Dade urban area, and the Biscayne Bay coast and simulates hydrodynamic surface-water flow and three-dimensional groundwater conditions dynamically for the period 1996–2004 by using the Flow and Transport in a Linked Overland/Aquifer Density-Dependent System (FTLOADDS) simulator. BISECT includes a number of parameter and algorithmic refinements that improve simulation results relative to the TIME and Biscayne models and represents the hydrologic system more explicitly, including (1) improved topographic representations, (2) refined Manning’s friction coefficients, (3) improved evapotranspiration computation through spatially variable albedo, (4) increased vertical aquifer discretization, and (5) extension of the western boundary farther offshore. Sensitivity analyses demonstrate that simulated flows into Long Sound have a different pattern of response to tidal amplitude, wind, and frictional resistance changes than do other coastal streams in the model; flows at Broad River and Lostmans River are most sensitive to tidal amplitude, wind, and frictional resistance changes; and flow to the Everglades coastal streams is substantially affected by surface-water/groundwater interactions in the eastern urban areas. Insight into the hydrologic system came from scenario simulations that represent proposed management actions, such as grouting of the aquifer to prevent seepage from the wetlands and changes to water deliveries proposed by the Comprehensive Everglades Restoration Plan (CERP), and projected sea-level rise. These scenario management changes are considered separately to isolate their specific effects and also in conjunction with sea-level rise. Scenario simulations show that (1) attempts to prevent seepage from the wetlands by grouting the aquifer along the L 31N levee produce minimal effects on surface-water levels; (2) the increased water deliveries proposed in the CERP redistribute flow to the northwestern coastal part of the study area with a minimal reduction to the southeast and a more substantial reduction in flows in the intervening coastal zones, mitigating some sea-level rise effects; (3) sea-level rise has a larger effect on the hydrology (water levels, flow, and salinity) than does CERP restoration; and (4) support for ecological models and hydrologic studies can be provided by applying BISECT to scenarios influenced by climatic and anthropogenic changes or by meteorological variability, such as extreme wet or dry periods.

Florida↗

Roadway runoff induced acute mortality in juvenile coho salmon during spring storm events

Extensive mortalities of adult coho salmon ( Oncorhynchus kisutch ), often called “Urban Runoff Mortality Syndrome” (URMS), have been documented during the fall in creeks where water quality has been degraded by roadway runoff. The primary cause of mortality is 6PPD-quinone (6PPDQ; N -(1,3-dimethylbutyl)- N ′-phenyl- p -phenylenediamine quinone)–an ozone transformation product that forms on all vehicle tires. Laboratory studies have shown that juvenile coho salmon are highly sensitive to 6PPDQ exposure. Unlike adults, juveniles reside in impacted watersheds year-round, including during the spring when 6PPDQ concentrations can frequently exceed lethal thresholds during storms. To assess the potential incidence of URMS in springtime rearing habitats for juvenile coho salmon, we conducted a paired water quality and toxicology study at Miller Creek, a runoff-impacted watershed in Normandy Park, WA, USA. Using a small field facility, three naïve groups of juvenile coho salmon ( N = 720) were exposed to either creek water or groundwater ( N = 120 per treatment per storm), across three spring storms while comparing water quality and mortality end points. In creek water during exposures, peak 6PPDQ concentrations reached 73–110 ng/L, exceeding reported median lethal concentrations (LC 50 ) for coho salmon. Over each 24–73 h storm exposure period, ∼80% of Miller Creek-exposed juvenile salmon died. No mortality occurred among control fish exposed to groundwater. These results indicate previously unidentified mortality risks for juvenile life stages of coho salmon during spring storms, suggesting substantial and year-round water quality impediments to coho salmon health and recovery across roadway runoff-impacted spawning, rearing, and migratory habitats.

Washington↗

The estimated six-year mercury dry deposition across North America

Dry deposition of atmospheric mercury (Hg) to various land covers surrounding 24 sites in North America was estimated for the years 2009 to 2014. Depending on location, multiyear mean annual Hg dry deposition was estimated to range from 5.1 to 23.8 μg m –2 yr –1 to forested canopies, 2.6 to 20.8 μg m –2 yr –1 to nonforest vegetated canopies, 2.4 to 11.2 μg m –2 yr –1 to urban and built up land covers, and 1.0 to 3.2 μg m –2 yr –1 to water surfaces. In the rural or remote environment in North America, annual Hg dry deposition to vegetated surfaces is dominated by leaf uptake of gaseous elemental mercury (GEM), contrary to what was commonly assumed in earlier studies which frequently omitted GEM dry deposition as an important process. Dry deposition exceeded wet deposition by a large margin in all of the seasons except in the summer at the majority of the sites. GEM dry deposition over vegetated surfaces will not decrease at the same pace, and sometimes may even increase with decreasing anthropogenic emissions, suggesting that Hg emission reductions should be a long-term policy sustained by global cooperation.

Environmental Science & Technology↗

Baseline reference range for trace metal concentrations in whole blood of wild and managed West Indian Manatees ( Trichechus manatus ) in Florida and Belize

The West Indian manatee ( Trichechus manatus ) is exposed to a number of anthropogenic influences, including metals, as they inhabit shallow waters with close proximity to shore. While maintaining homeostasis of many metals is crucial for health, there is currently no baseline reference range that can be used to make clinical and environmental decisions for this endangered species. In this study, whole blood samples from 151 manatees were collected during health assessments performed in Florida and Belize from 2008 through 2011. Whole blood samples (n = 37) from managed care facilities in Florida and Belize from 2009 through 2011 were also used in this study. The concentrations of 17 metals in whole blood were determined, and the data were used to derive a baseline reference range. Impacts of capture location, age, and sex on whole blood metal concentrations were examined. Location and age were related to copper concentrations as values were significantly higher in habitats near urban areas and in calves. Copper may also be a husbandry concern as concentrations were significantly higher in managed manatees (1.17 ± 0.04 ppm) than wild manatees (0.73 ± 0.02 ppm). Zinc (11.20 ± 0.30 ppm) was of special interest as normal concentrations were two to five times higher than other marine mammal species. Arsenic concentrations were higher in Belize (0.43 ± 0.07 ppm), with Placencia Lagoon having twice the concentration of Belize City and Southern Lagoon. Selenium concentrations were lower (0.18 ± 0.09 ppm) than in other marine mammal species. The lowest selenium concentrations were observed in rehabilitating and managed manatees which may warrant additional monitoring in managed care facilities. The established preliminary baseline reference range can be used by clinicians, biologists, and managers to monitor the health of West Indian manatees.

Aquatic Mammals↗

Water resources in a rapidly growing region: Oakland County, Michigan

Oakland County is a suburban county in southeast Michigan. Population and demand for water grew steadily in the county over the 20th century, and these trends are expected to continue in coming decades. Roughly 75 percent of current water demand is met by imported water from the Detroit Water and Sewerage Division (DWSD), but water use from ground-water sources within the county still exceeds 43 million gallons per day. Because much of the population growth is in areas beyond the DWSD system, an additional 20-25 million gallons per day of supply may be necessary to meet future demands. Managing the wastewater produced while also protecting human and ecosystem health also may present challenges. Despite considerable expansion of urban areas, streamflow characteristics at most sites have not been affected. However, at several sites in areas of the county that are both supplied by ground water and sewered, statistically significant downward trends in low-flow stream discharges have been noted between 1970 and 2003. Stream chemistry, compared to a previous study of county water resources prepared in 1972, has generally improved, with marked decreases in concentrations of nitrogen, phosphorus, and sulfate. Chloride concentrations, however, have increased dramatically in river and lake water across the county. Detectable concentrations of personal-care products, flame retardants, and petroleum fuel compounds were identified at all river sites sampled.

Michigan↗

Chemical mixtures and environmental effects: a pilot study to assess ecological exposure and effects in streams

Assessment and management of the risks of exposure to complex chemical mixtures in streams are priorities for human and environmental health organizations around the world. The current lack of information on the composition and variability of environmental mixtures and a limited understanding of their combined effects are fundamental obstacles to timely identification and prevention of adverse human and ecological effects of exposure. This report describes the design of a field-based study of the composition and biological activity of chemical mixtures in U.S. stream waters affected by a wide range of human activities and contaminant sources. The study is a collaborative effort by the U.S. Geological Survey and the U.S. Environmental Protection Agency. Scientists sampled 38 streams spanning 24 States and Puerto Rico. Thirty-four of the sites were located in watersheds impacted by multiple contaminant sources, including industrial and municipal wastewater discharges, crop and animal agricultural runoff, urban runoff, and other point and nonpoint contaminant sources. The remaining four sites were minimally development reference watersheds. All samples underwent comprehensive chemical and biological characterization, including sensitive and specific direct analysis for over 700 dissolved organic and inorganic chemicals and field parameters, identification of unknown contaminants (environmental diagnostics), and a variety of bioassays to evaluate biological activity and toxicity.

Open-File Report↗

Sources and occurrence of chloroform and other trihalomethanes in drinking-water supply wells in the United States, 1986-2001

Chloroform and three other trihalomethanes (THMs)--bromodichloromethane, dibromochloromethane, and bromoform--are disinfection by-products commonly produced during the chlorination of water and wastewater. Samples of untreated ground water from drinking-water supply wells (1,096 public and 2,400 domestic wells) were analyzed for THMs and other volatile organic compounds (VOCs) during 1986-2001, or compiled, as part of the U.S. Geological Survey's National Water-Quality Assessment Program. This report provides a summary of potential sources of THMs and of the occurrence and geographical distribution of THMs in samples from public and domestic wells. Evidence for an anthropogenic source of THMs and implications for future research also are presented. Potential sources of THMs to both public and domestic wells include the discharge of chlorinated drinking water and wastewater that may be intentional or inadvertent. Intentional discharge includes the use of municipally supplied chlorinated water to irrigate lawns, golf courses, parks, gardens, and other areas; the use of septic systems; or the regulated discharge of chlorinated wastewater to surface waters or ground-water recharge facilities. Inadvertent discharge includes leakage of chlorinated water from swimming pools, spas, or distribution systems for drinking water or wastewater sewers. Statistical analyses indicate that population density, the percentage of urban land, and the number of Resource Conservation and Recovery Act hazardous-waste facilities near sampled wells are significantly associated with the probability of detection of chloroform, especially for public wells. Domestic wells may have several other sources of THMs, including the practice of well disinfection through shock chlorination, laundry wastewater containing bleach, and septic system effluent. Chloroform was the most frequently detected VOC in samples from drinking-water supply wells (public and domestic wells) in the United States. Although chloroform was detected frequently in samples from public and domestic wells and the other THMs were detected in some samples, no concentrations in samples from either well type exceeded the U.S. Environmental Protection Agency's Maximum Contaminant Level of 80 micrograms per liter for total THMs. Chloroform was detected in public well samples almost twice as frequently (11 percent) as in domestic well samples (5 percent). The other three THMs also were detected more frequently in public well samples than in domestic well samples. This detection pattern may be attributed to public wells having a higher pumping capacity than domestic wells. The higher capacity wells create a larger capture zone that potentially intercepts more urban and other land uses and associated point and nonpoint sources of contamination than the smaller capacity domestic wells. THM detection frequencies in domestic well samples show a pattern of decreasing frequency with increasing bromide content, that is in the order: chloroform > bromodichloromethane >= dibromochloromethane >= bromoform. This same pattern has been documented in studies of water chlorination, indicating that an important source of chloroform and other THMs in drinking-water supply wells may be the recycling of chlorinated water and wastewater. Mixtures of THMs commonly occur in public well samples, and the most frequently occurring are combinations of the brominated THMs. These THMs have limited industrial production, few natural sources, and small or no reported direct releases to the environment. Therefore, industrial, commercial, or natural sources are not likely sources of the brominated THMs in public and domestic well samples. The THM detection frequency pattern, the co-occurrence of brominated THMs, and other lines of evidence indicate that the recycling of water with a history of chlorination is an important source of these compounds in samples from drinking-water supply wells.

Scientific Investigations Report↗

Occurrence of antibiotic compounds in source water and finished drinking water from the upper Scioto River Basin, Ohio, 2005-6

The occurrence of antibiotics in surface water and groundwater in urban basins has become a topic of increasing interest in recent years. Little is known about the occurrence, fate, or transport of these compounds and the possible health effects in humans and aquatic life. The U.S. Geological Survey, in cooperation with the City of Columbus, Division of Power and Water, did a study to provide a synoptic view of the occurrence of antibiotics in source and finished waters in the upper Scioto River Basin. Water samples were collected seasonally-winter (December 2005), spring (May 2006), summer (August 2006) and fall (October 2006)-at five surface-water sites, one groundwater site, and three water-treatment plants (WTPs). Within the upper Scioto River Basin, sampling at each WTP involved two sampling sites: a source-water intake site and a finished-water site. One or more antibiotics were detected at 11 of the 12 sampling sites. Of the 49 targeted antibiotic compounds, 12 (24 percent) were detected at least one time for a total of 61 detections overall. These compounds were azithromycin, tylosin, erythromycin-H2O, erythromycin, roxithromycin, ciprofloxacin, ofloxacin, sulfamethazine, sulfamethoxazole, iso-chlorotetracycline, lincomycin, and trimethoprim. Detection results were at low levels, with an overall median of 0.014 (u or mu)g/L. Hap Cremean WTP had the fewest detections, with two source-water detections of sulfamethoxazole and azithromycin and no detections in the finished water. Of the total of 61 detections, 31 were in the winter sample run. Sulfamethoxazale and azithromycin detections represent 41 percent of all antibiotic detections. Azithromycin was detected only in the winter sample. Some antibiotics, such as those in the quinoline and tetracycline families, dissipate more quickly in warm water, which may explain why they were detected in the cool months (winter, spring, and fall) and not in the summer. Antibiotic data collected during this study were compared to antibiotic data collected in previous national, regional, and local studies. Many of the same antibiotic compounds detected in the upper Scioto River Basin also were detected in those investigations.

Ohio↗

Water-quality and biological conditions in selected tributaries of the Lower Boise River, southwestern Idaho, water years 2009-12

Water-quality conditions were studied in selected tributaries of the lower Boise River during water years 2009–12, including Fivemile and Tenmile Creeks in 2009, Indian Creek in 2010, and Mason Creek in 2011 and 2012. Biological samples, including periphyton biomass and chlorophyll-a, benthic macroinvertebrates, and fish were collected in Mason Creek in October 2011. Synoptic water-quality sampling events were timed to coincide with the beginning and middle of the irrigation season as well as the non-irrigation season, and showed that land uses and irrigation practices affect water quality in the selected tributaries. Large increases in nutrient and sediment concentrations and loads occurred over relatively short stream reaches and affected nutrient and sediment concentrations downstream of those reaches. Escherichia coli (E. coli) values increased in study reaches adjacent to pastured lands or wastewater treatment plants, but increased E. coli values at upstream locations did not necessarily affect E. coli values at downstream locations. A spatial loading analysis identified source areas for nutrients, sediment, and E. coli , and might be useful in selecting locations for water-quality improvement projects. Effluent from wastewater treatment plants increased nutrient loads in specific reaches in Fivemile and Indian Creeks. Increased suspended-sediment loads were associated with increased discharge from irrigation returns in each of the studied tributaries. Samples collected during or shortly after storms showed that surface runoff, particularly during the winter, may be an important source of nutrients in tributary watersheds with substantial agricultural land use. Concentrations of total phosphorus, suspended sediment, and E. coli exceeded regulatory water-quality targets or trigger levels at one or more monitoring sites in each tributary studied, and exceedences occurred during irrigation season more often than during non-irrigation season. As with water-quality sampling results, bottom-sediment samples analyzed for contaminants of emerging concern indicated that adjacent land uses can affect in-stream conditions. Contaminants of emerging concern were detected in four categories: urban compounds, industrial compounds, fecal steroids, and personal care products. Compounds in one or more of the four contaminant categories were detected at higher concentrations in upstream sites than in downstream sites in the tributaries and in the lower Boise River. High concentrations of compounds in upstream locations indicated that adjacent land use might be an important factor in contributing contaminants of emerging concern to the lower Boise River watershed. Expanded monitoring at Mason Creek near the mouth included a streamgage, a continuous water-quality monitor, and monthly water-quality sample collection. Data collected during expanded monitoring efforts at Mason Creek near the mouth provided information to develop and compare water-quality models. Regression models were developed using turbidity, discharge, and seasonality as surrogates to estimate concentrations of water-quality constituents. Daily streamflow also was used in a load model to estimate daily loads of water-quality constituents. Surrogate regression models may be useful for long-term monitoring and generally performed better than other models to estimate concentrations and loads of total phosphorus, total nitrogen, and suspended sediment in Mason Creek. Biological sampling results from Mason Creek showed low periphyton biomass and chlorophyll-a concentrations compared to those historically measured in the Boise River near Parma, Idaho, during October and November. The most abundant invertebrate found in Mason Creek was the highly tolerant and invasive New Zealand mudsnail ( Potamopyrgus antipodarum ). The presence of small rainbow trout (90 millimeters) may indicate salmonid spawning in Mason Creek. The rangeland-fish-index score of 58 for Mason Creek is comparable to rangeland-fish-index scores calculated for the Boise River near Middleton, indicating intermediate biotic condition.

Idaho↗

Application of a watershed model (HSPF) for evaluating sources and transport of pathogen indicators in the Chino Basin drainage area, San Bernardino County, California

A watershed model using Hydrologic Simulation Program-FORTRAN (HSPF) was developed for the urbanized Chino Basin in southern California to simulate the transport of pathogen indicator bacteria, evaluate the flow-component and land-use contributions to bacteria contamination and water-quality degradation throughout the basin, and develop a better understanding of the potential effects of climate and land-use change on water quality. The calibration of the model for indicator bacteria was supported by historical data collected before this study and by samples collected by the U.S. Geological Survey from targeted land-use areas during storms in water-year 2004. The model was successfully calibrated for streamflow at 5 gage locations representing the Chino Creek and Mill Creek drainages. Although representing pathogens as dissolved constituents limits the model's ability to simulate the transport of pathogen indicator bacteria, the bacteria concentrations measured over the period 1998-2004 were well represented by the simulated concentrations for most locations. Hourly concentrations were more difficult to predict because of high variability in measured bacteria concentrations. In general, model simulations indicated that the residential and commercial land uses were the dominant sources for most of the pathogen indicator bacteria during low streamflows. However, simulations indicated that land used for intensive livestock (dairies and feedlots) and mixed agriculture contributed the most bacteria during storms. The calibrated model was used to evaluate how various land use, air temperature, and precipitation scenarios would affect flow and transport of bacteria. Results indicated that snow pack formation and melt were sensitive to changes in air temperature in the northern, mountainous part of the Chino Basin, causing the timing and magnitude of streamflow to shift in the natural drainages and impact the urbanized areas of the central Chino Basin. The relation between bacteria concentrations and air temperature was more complicated, and did not substantially affect the quality of water discharging from the Chino Basin into the Santa Ana River. Changes in precipitation had a greater basin-wide affect on bacteria concentrations than changes in air temperature, and varied according to location. Drainages representing natural conditions had a decrease in bacteria concentrations in correlation with an increase in precipitation, whereas drainages in the central and southern part of the Chino Basin had an increase in bacteria concentrations. Drier climate conditions tended to result in higher sensitivity of simulated bacteria concentrations to changes in precipitation. Simulated bacteria concentrations in wetter climates were usually less sensitive to changes in precipitation because bacteria transport becomes more dependent on the land-use specified bacteria loading rates and the storage limits. Bacteria contamination from impervious-area runoff is affected to a greater degree by drier climates, whereas contamination from pervious-area runoff is affected to a greater degree by wetter climates. Model results indicated that the relation between precipitation, runoff, and bacteria contamination is complicated because after the initial bacteria washoff and transport from the land surfaces during the beginning of a storm period, subsequent runoff has fewer bacteria available for washoff, which then dilutes the concentrations of bacteria in the downstream reach. It was illustrated that pathogen indicator bacteria transport depends most significantly on the relation of imperviousness to runoff, which controls the frequency, and often the magnitude, of transport, and on the contribution of higher bacteria loading rates used for pervious land areas, especially intensive feedlots, to the infrequent, but very high, peaks of bacteria contamination. The indicator bacteria transport model for the Chino Basin was based on the assumption that no

California↗

Surface-water-quality assessment of the Yakima River basin, Washington: Project description

In April 1986, the U.S. Geological Survey began the National Water Quality Assessment program to: (1) provide a nationally consistent description of the current status of water quality, (2) define water quality trends that have occurred over recent decades, and (3) relate past and present water quality conditions to relevant natural features, the history of land and water use, and land management and waste management practices. At present (1987), The National Water Quality Assessment program is in a pilot studies phase, in which assessment concepts and approaches are being tested and modified to prepare for possible full implementation of the program. Seven pilot projects (four surface water projects and three groundwater projects) have been started. The Yakima River basin in Washington is one of the pilot surface water project areas. The Yakima River basin drains in area of 6,155 sq mi and contains about 1,900 river mi of perennial streams. Major land use activities include growing and harvesting timber, dryland pasture grazing, intense farming and irrigated agriculture, and urbanization. Water quality issues that result from these land uses include potentially large concentrations of suspended sediment, bacteria, nutrients, pesticides, and trace elements that may affect water used for human consumption, fish propagation and passage, contact recreation, livestock watering, and irrigation. Data will be collected in a nine year cycle. The first three years of the cycle will be a period of concentrated data acquisition and interpretation. For the next six years, sample collection will be done at a much lower level of intensity to document the occurrence of any gross changes in water quality. This nine year cycle would then be repeated. Three types of sampling activities will be used for data acquisition: fixed location station sampling, synoptic sampling, and intensive reach studies. (Lantz-PTT)

Washington↗