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Occurrence and distribution of methyl tert-butyl ether and other volatile organic compounds in drinking water in the Northeast and Mid-Atlantic regions of the United States, 1993-98

Data on volatile organic compounds (VOCs) in drinking water supplied by 2,110 randomly selected community water systems (CWSs) in 12 Northeast and Mid-Atlantic States indicate 64 VOC analytes were detected at least once during 1993-98. Selection of the 2,110 CWSs inventoried for this study targeted 20 percent of the 10,479 active CWSs in the region and represented a random subset of the total distribution by State, source of water, and size of system. The data include 21,635 analyses of drinking water collected for compliance monitoring under the Safe Drinking Water Act; the data mostly represent finished drinking water collected at the pointof- entry to, or at more distal locations within, each CWS?s distribution system following any watertreatment processes. VOC detections were more common in drinking water supplied by large systems (serving more than 3,300 people) that tap surface-water sources or both surface- and groundwater sources than in small systems supplied exclusively by ground-water sources. Trihalomethane (THM) compounds, which are potentially formed during the process of disinfecting drinking water with chlorine, were detected in 45 percent of the randomly selected CWSs. Chloroform was the most frequently detected THM, reported in 39 percent of the CWSs. The gasoline additive methyl tert-butyl ether (MTBE) was the most frequently detected VOC in drinking water after the THMs. MTBE was detected in 8.9 percent of the 1,194 randomly selected CWSs that analyzed samples for MTBE at any reporting level, and it was detected in 7.8 percent of the 1,074 CWSs that provided MTBE data at the 1.0-?g/L (microgram per liter) reporting level. As with other VOCs reported in drinking water, most MTBE concentrations were less than 5.0 ?g/L, and less than 1 percent of CWSs reported MTBE concentrations at or above the 20.0-?g/L lower limit recommended by the U.S. Environmental Protection Agency?s Drinking-Water Advisory. The frequency of MTBE detections in drinking water is significantly related to high- MTBE-use patterns. Detections are five times more likely in areas where MTBE is or has been used in gasoline at greater than 5 percent by volume as part of the oxygenated or reformulated (OXY/RFG) fuels program. Detection frequencies of the individual gasoline compounds (benzene, toluene, ethylbenzene, and xylenes (BTEX)) were mostly less than 3 percent of the randomly selected CWSs, but collectively, BTEX compounds were detected in 8.4 percent of CWSs. BTEX concentrations also were low and just three drinkingwater samples contained BTEX at concentrations exceeding 20 ?g/L. Co-occurrence of MTBE and BTEX was rare, and only 0.8 percent of CWSs reported simultaneous detections of MTBE and BTEX compounds. Low concentrations and cooccurrence of MTBE and BTEX indicate most gasoline contaminants in drinking water probably represent nonpoint sources. Solvents were frequently detected in drinking water in the 12-State area. One or more of 27 individual solvent VOCs were detected at any reporting level in 3,080 drinking-water samples from 304 randomly selected CWSs (14 percent) and in 206 CWSs (9.8 percent) at concentrations at or above 1.0 ?g/L. High co-occurrence among solvents probably reflects common sources and the presence of transformation by-products. Other VOCs were relatively rarely detected in drinking water in the 12-State area. Six percent (127) of the 2,110 randomly selected CWSs reported concentrations of 16 VOCs at or above drinking-water criteria. The 127 CWSs collectively serve 2.6 million people. The occurrence of VOCs in drinking water was significantly associated (p<0.0001) with high population- density urban areas. New Jersey, Massachusetts, and Rhode Island, States with substantial urbanization and high population density, had the highest frequency of VOC detections among the 12 States. More than two-thirds of the randomly selected CWSs in New Jersey reported detecting VOC concentrations in drinking water at or above 1

Water-Resources Investigations Report

North Central Climate Adaptation Science Center regional science plan—2023–28

The U.S. Geological Survey North Central Climate Adaptation Science Center (NC CASC), established in 2012, is part of a national network supporting climate-informed decisions that benefit wildlife and habitats. The NC CASC provides climate science for the U.S. Department of the Interior, State agencies, and Tribal nations to support effective resource management. Collaborating with the National and Regional Climate Adaptation Science Center network, the NC CASC addresses multiregion challenges through a partnership involving the U.S. Geological Survey and additional regional partners. Input is collected from an Advisory Committee of State, Federal, and Tribal Government representatives. The center hosts Tribal Climate Resilience Liaisons, which are funded by the Bureau of Indian Affairs Branch of Tribal Climate Resilience and aligned with a Tribal Engagement Strategy. Positioned at the meeting point of scientists and managers and guided by core values, the NC CASC studies diverse ecosystems affected by climate change and empowers resource managers with actionable data and innovative science. This report outlines the 5-year Science Plan (hereafter “the Plan”) for the NC CASC. The center uses stakeholder engagement and coproduction of knowledge for effective collaboration, including engagement of Advisory Committee members and other management partners in the development of the Plan. The Plan provides a high-level overview of the NC CASC, covering the center’s geographical scope, key collaborators, stakeholders, and the strategic framework guiding the application of climate science to make informed management decisions. The Plan also summarizes management challenges and scientific objectives related to the impact of climate change on habitat, ecological drought, wildlife disease, invasives and encroachment, fire, and phenology.

Colorado, Kansas, Montana, North Dakota, Nebraska,

Herbicides and nitrate in near-surface aquifers in the midcontinental United States, 1991

The occurrence and distribution of selected herbicides, atrazine metabolites, and nitrate were determined for near-surface aquifers (within 50 feet of land surface) in the corn- and soybean-producing region of the midcontinental United States. The study region included all or parts of Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. Water samples were collected during the spring and summer of 1991 from 303 wells completed in near-surface unconsolidated and near-surface bedrock aquifers. At least one herbicide or atrazine metabolite was detected in 24 percent of 579 water samples analyzed for herbicides, based on a reporting limit of 0.05 microgram per liter. However, no herbicide concentration exceeded the U.S. Environmental Protection Agency's maximum contaminant levels or health advisory levels for drinking water. The most frequently detected herbicide compound was desethylatrazine, an atrazine metabolite (18.1 percent), followed by atrazine (17.4 percent); deisopropylatrazine, an atrazine metabolite (5.7 percent); prometon (5.0 percent); metolachlor (2.7 percent); alachlor (1.7 percent); simazine (1.0 percent); metribuzin (1.0 percent); and cyanazine (0.7 percent). The herbicides ametryn, prometryn, propazine, and terbutryn were not detected during this study. Nitrate concentrations equal to or greater than 3.0 milligrams per liter (excess nitrate) were detected in 29 percent of the 599 nitrate analyses, and ammonium concentrations equal to or greater than 0.01 milligram per liter were detected in 78 percent of the 584 ammonium analyses. Nitrate concentrations equal to or greater than the U.S. Environmental Protection Agency's maximum contaminant level for drinking water of 10 milligrams per liter were found in 6 percent of the samples. The frequency of herbicide detection was, in part, affected by the analytical method's reporting limit. Results from this study show that the frequency of atrazine detection increases as the reporting limit decreases. Herbicide metabolite concentrations are critical to understanding the detection of herbicide residues. The frequency of detection of atrazine residue (atrazine + desethylatrazine + deisopropylatrazine) was 22.1 percent, which was more than the frequency of detection of atrazine alone (17.4 percent). Prometon was detected more frequently than every other herbicide except atrazine. The prometon appears to be derived from areas of nonagricultural land use, such as golf courses and residential areas. Herbicides and excess nitrate were both rarely detected in the eastern part of the study region, even though this is an area of intense herbicide and nitrogen-fertilizer use. Hydrogeologic factors, land use, agricultural practices, local features, and water chemistry were analyzed for possible relation to herbicide and excess-nitrate detections. Herbicides and excess nitrate were detected more frequently in near-surface unconsolidated aquifers than in nearsurface bedrock aquifers. The depth to the top of the aquifer was inversely related to the frequency of detection of herbicides and excess nitrate. The proximity of streams to sampled wells also affected the frequency of herbicide detection. Significant seasonal differences were determined for the frequency of herbicide detection, but not for the frequency of excess nitrate.

Illinois, Indiana, Iowa, Kansas, Michigan, Minneso

Phytoplankton, taste-and-odor compounds, and cyanotoxin occurrence in four water-supply reservoirs in the Triangle area of North Carolina, April–October 2014

Prior to 2014, local utilities and State agencies monitored for cyanotoxins and taste-and-odor (T&O) compounds and reported occasional detections in three water-supply reservoirs in Wake County, North Carolina. Comparable data for cyanotoxins and T&O compounds were lacking for other water-supply reservoirs in the Triangle area of North Carolina. This report assesses whether cyanotoxins and T&O compounds occurred in four previously unmonitored North Carolina Triangle area water-supply reservoirs at levels that exceed existing North Carolina and U.S. Environmental Protection Agency recreational and drinking water health advisory, guidance, and criterion levels based on data collected during the peak phytoplankton growth period in 2014. Samples were collected from five sites across the study reservoirs (Cane Creek Reservoir, West Fork Eno River Reservoir, B. Everett Jordan Lake, and University Lake) between April and October 2014 and analyzed for physical characteristics, chemical constituents, phytoplankton communities, cyanotoxins, and T&O compounds. Lake stratification during the sampling period in 2014 could indicate that the deep zones of the water column, during stratified anoxic conditions, may serve as possible sources of nutrients and metals for algal growth and other biogeochemical processes. Differences in phytoplankton communities were attributed to variability in environmental conditions across the sites and sampling events. Differences generally were greater among sites than among sampling events for phytoplankton communities and environmental conditions. Phytoplankton community assemblages, within reservoirs, often were dominated by cyanobacteria that contained genera capable of producing T&O compounds and cyanotoxins during summer and fall months. The occurrence and associated biovolumes of potential producers of cyanotoxins and T&O compounds varied across the sites and sampling events. Of 20 samples collected during the study, the T&O compound geosmin and the cyanotoxin microcystin were present in 19 and 18 samples, respectively. While not harmful, the aesthetically displeasing geosmin concentrations periodically exceeded the human detection threshold of 15 nanograms per liter at most sites. The T&O compound 2-methylisoborneol (MIB) was detected in 11 of 20 samples, with concentrations below the human detection threshold of 15 nanograms per liter in all but one sample. The cyanotoxin anatoxin-a was detected in two of the samples. No other cyanotoxins were detected during the study. In general, results did not indicate the biovolume of any given phytoplankton genera in the study was correlated with increased concentrations of MIB, geosmin, or microcystin. Results from this study indicated that microcystin concentrations in the water-supply reservoirs in the Triangle area were below EPA-recommended recreational level of 8 micrograms per liter, but periodically exceeded the EPA finished-water 10-day health advisory level of 0.3 microgram per liter for bottle-fed infants and preschool-age children. This suggests longer term data collection may be necessary to better understand the magnitude and frequency of cyanotoxin concentrations in these four water-supply reservoirs, particularly those with an elevated risk of exceeding the EPA 10-day health advisory levels in the finished drinking water or those with a higher frequency of T&O compound occurrence.

North Carolina

Use of U.S. Geological Survey earth-science products by selected regional agencies in the San Francisco Bay region, California

An inventory of the use of U.S. Geological Survey (USGS) products in studies, plans, implementation, and other planning activities was made for seven selected regional agencies in the San Francisco Bay region -- a region of over five million people. This inventory was designed to determine and document the use of over 100 earth-science products prepared as a part of the San Francisco Bay Region Environment and Resources Planning Study (SFBRS). The inventory showed that: (1) all seven agencies have staff members who are familiar with SFBRS products and make frequent use of them; (2) all seven agencies have prepared planning documents citing SFBRS products; (3) the types of planning applications most often indicated were water-quality and physical resources studies, potential site evaluation, and general reference; (4) almost 80 percent of the over 100 SFBRS products were used at least once, and eleven of the products were used 20 or more times each for various regional planning activities; and (5) at least 46 other USGS products were also used for various regional planning activities. During the inventory, over 50 regional agency. officials, employees, and consultants were interviewed and asked -- among other things -- to indicate any problems they had noted in the use of the SFBRS products, to suggest improvements, and to identify any additional earth-science information needed or desired. The responses showed that: (1) the scales commonly used for "work" maps were 1:62,500 or larger, and for "implementation" maps were 1:24,000 or larger; (2) two agencies have a geologist on their planning staff, others have staff members with training or experience in earth-science or engineering, and all had the benefit of geotechnical services from outside their agency; (3) all seven agencies experienced some problems in using the products, primarily because the scale was too small or the detail not great enough; (4) all seven agencies expressed interest in the topical interpretive reports in preparation and a need or desire for additional earth-science, engineering, or other related information; (5) six of the seven agencies suggested specific improvements to future products -- primarily larger scale or more detail and less technical or more interpretive information; and (6) all seven agencies received educational, advisory or review services from USGS personnel. Fifteen selected examples of the application of SFBRS products to various regional planning activities are discussed and illustrated. These examples include six planning studies, five plans, two implementation activities, and two other types of activities. From the inventory and responses to the interviews, it is concluded that the selected regional agencies in the bay region are familiar with, make frequent use of, and will continue to use SFBRS products for a wide range of regional planning activities. Suggestions to ensure more effective use of earth-science information in the future include: (1) monitoring and analyzing new State and Federal laws or regulations and emerging critical issues so as to anticipate and respond to regional earth-science information needs; (2) creating a users advisory committee to help identify critical issues and needs; (3) providing engineering interpretations and land- and water-use capability ratings to make earth-science information more readily usable; (4) giving priority to areas impacted by development; (5) providing earth-science information at the larger scale and greater detail commonly used and needed by regional agencies; (6) releasing earth-science information faster and according to a formal distribution pattern; and (7) providing educational, advisory, and review services in connection with any earth-science information designed for planners and decisionmakers.

California

Characterization of streamflow and nutrient occurrence in the upper White River Basin, Colorado, 1980–2020

In 2016, Colorado Parks and Wildlife identified filamentous algae collected from the main stem White River as Cladophora glomerata , a pervasive nuisance aquatic alga. Excessive levels of filamentous algae can compromise aesthetic quality, limit recreational activities, and have negative effects on aquatic life including strong fluctuations in dissolved oxygen levels and a reduction in overall biodiversity. To increase understanding of the biology of the upper White River Basin in Colorado, identify potential factors promoting or limiting nuisance algal abundance, and outline information to aid in the understanding and protection of water resources, the U.S. Geological Survey (USGS), in cooperation with the White River and Douglas Creek Conservation Districts and the White River Algae Technical Advisory Group, initiated a study to collect and analyze physical, chemical, and biological information for the upper White River Basin. The report describes long-term changes and spatial variations in streamflow and nutrient concentrations and loads in the upper White River Basin and identifies possible nutrient sources in the basin. Long-term streamflow and nutrient data indicate that conditions in the upper White River Basin have become more favorable to benthic algae over varying timescales. Upward trends in total phosphorus concentrations and loads were found at three sites across the basin from 2000 to 2020. Total phosphorus loads increased around 50 percent, ranging from 18 to 48 pounds per year. Annual estimated concentrations of total phosphorus from 2005 to 2020 were above algal-specific nutrient criteria at the North Fork White River at Buford, Colo., indicating that phosphorus concentrations at this site likely promote algal growth. Discrete concentrations of total phosphorus exceeded algal-specific nutrient criteria on the South Fork and main stem White River during the summer season, though less frequently than samples collected from the North Fork White River. Nitrogen to phosphorus molar ratios collected from July to September indicate movement from colimitation (10–22) to nitrogen limited (less than 13) conditions at the North Fork White River at Buford, Colo. and the South Fork White River at Buford, Colo. starting in 2012. The magnitude of trends in phosphorus loads were generally greater than trends in concentrations across all sites, indicating that the largest changes in concentrations occurred during greater streamflow periods. At White River above Coal Creek, near Meeker, Colo., significant downward trends in streamflow were found in August and September for mean streamflow (15 and 14 percent per decade, respectively) and 7-day minimum streamflows (23 and 22 percent per decade, respectively). Significant downward trends in annual 7-day minimum streamflows of 24 percent per decade, or 66 percent over the 40-year period of analysis, were also observed. Though not significant based on 90-percent confidence intervals, downward trends in 1-day maximum and mean streamflows in May and June and corresponding increases in April may indicate a shift toward earlier snowmelt runoff, as observed across western North America and the Colorado River Basin. Alteration of the annual hydrograph can influence factors that influence algae including nutrient input and dilution potential, water temperature, dissolved oxygen, light availability, and physical disturbance. Results from a synoptic-style sampling identified the lower North Fork White River subbasin as a large source of phosphorus to the downstream system. Large increases in phosphorus loads were observed below Marvine Creek. Synoptic samples and samples collected during spring and summer of 2019 and 2020 also show large increases in total nitrogen, orthophosphate, and total phosphorus occurring at the furthest three downstream sites on the White River. To further evaluate sources of nitrogen in the upper White River Basin, the dual isotopic composition of nitrate was compared across four sites. The isotopic compositions of nitrate were all within the expected range of typical soil-derived nitrate, though the same values can also be derived from a mixture of agricultural fertilizer and manure or septic sources.

Colorado

Determination of total mercury in fillets of sport fishes collected from Folsom and New Melones Reservoirs, California, 2004

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom and New Melones Reservoirs in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fish fillets from Folsom Reservoir ranged from 0.09 to 1.16 micrograms per gram wet weight, and from New Melones Reservoir ranged from 0.03 to 0.94 microgram per gram wet weight. Most of the fish fillets from Folsom Reservoir (87 percent) and 27 percent of the fillets from New Melones Reservoir exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

Open-File Report

Determination of total mercury in fillets of sport fishes collected from Folsom Reservoir, California, 2006

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom Reservoir in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fillets ranged from 0.031 to 0.20 micrograms per gram wet weight in rainbow trout (Oncorhynchus mykiss) samples and 0.071 to 0.16 micrograms per gram wet weight in bluegill (Lepomis macrochirus) samples. Mercury concentration was 0.98 microgram per gram wet weight in a single spotted bass (Micropterus punctulatus) sample, which was the only one in the sample set which exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

Open-File Report

Determination of total mercury in whole-body fish and fish muscle plugs collected from the South Fork of the Humboldt River, Nevada, September 2005

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in whole-body fish and fish muscle plugs from the South Fork of the Humboldt River near Elko in the Te-Moak Indian Reservation. A single muscle plug was collected from beneath the dorsal fin area in each of the three whole-body fish samples. After homogenization and lyophilization of the muscle plugs and whole-body fish samples, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in whole-body fish ranged from 0.048 to 0.061 microgram per gram wet weight, and 0.061 to 0.082 microgram per gram wet weight in muscle plugs. All sample mercury concentrations were well below the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

Open-File Report

Proceedings of the Federal Interagency Sediment Monitoring Instrument and Analysis Research Workshop, September 9-11, 2003, Flagstaff, Arizona

The Advisory Committee on Water Information's Subcommittee on Sedimentation sponsored the Federal Interagency Sediment Monitoring Instrument and Analysis Research Workshop on September 9-11, 2003, at the U.S. Geological Survey Flagstaff Field Center, Arizona. The workshop brought together a diverse group representing most Federal agencies whose mission includes fluvial-sediment issues; academia; the private sector; and others with interests and expertise in fluvial-sediment monitoring ? suspended sediment, bedload, bed material, and bed topography ? and associated data-analysis techniques. The workshop emphasized technological and theoretical advances related to measurements of suspended sediment, bedload, bed material and bed topography, and data analyses. This workshop followed and expanded upon part of the 2002 Federal Interagency Workshop on Turbidity and Other Sediment Surrogates (http://water.usgs.gov/pubs/circ/2003/circ1250/), which initiated a process to provide national standards for measurement and use of turbidity and other sediment-surrogate data. This report provides a description of the salient attributes of the workshop and related information, major deliberations and findings, and principal recommendations. This information is available for evaluation by the Subcommittee on Sedimentation, which may opt to develop an action plan based on the recommendations that it endorses for consideration by the Advisory Committee on Water Information.

Circular

Testing and refining the Ohio Nowcast at two Lake Erie beaches— 2008

The Ohio Nowcast has been providing real-time beach advisories to the public on the basis of predictive models since 2006. In support of the nowcast, data were collected during the recreational season of 2008 to validate and refine predictive models at two Lake Erie beaches. Predictive models yield data on the probability that the single-sample bathing-water standard for E. coli will be exceeded. Field personnel collected or compiled data on Escherichia coli (E. coli) concentrations as well as variables expected to affect these concentrations, including manual and automated measurements of turbidity, wave height, and water temperature; lake level; and radar and airport rainfall amounts. Two new variables were measured during 2008 - photosynthetically-active radiation at Huntington (Bay Village) and foreshore head at Edgewater (Cleveland). (The foreshore is a strip of land along a body of water between low and high water marks.) The performance of the nowcast was monitored during 2008. The Huntington nowcast yielded a greater percentage of correct responses (84.9 percent) than did the previous day's E. coli concentration (75.2 percent). In contrast, at Edgewater, the nowcast yielded a slightly higher percentage of correct responses (61.0 percent) as compared to the previous day's E. coli concentration (56.5 percent), but both percentages were relatively low. Lake levels in 2008 were significantly higher than levels in the data used to develop the Edgewater models (2004-7), confounding their abilities to provide correct responses. At Edgewater during 2008, the strongest relation (as measured by Pearson's correlation) was between E. coli concentrations and the difference in foreshore head over the past 24 hours (r=0.48), a variable not included in the models. At Huntington, photosynthetically-active radiation on the previous day showed a significant negative relation to E. coli concentrations (r=-0.33) during 2008. Refined models were developed for Huntington and Edgewater using data collected from 2005-8. The refined models included the variables wave height, log turbidity, radar or airport rainfall, and day of the year in various combinations for different dated segments of the recreational season. Water-resource managers will determine which models to apply to the Ohio Nowcast for issuing water-quality advisories in 2009.

Ohio

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas — Surface-water quality, shallow ground-water quality, and factors affecting water quality in the Rincon Valley, south-central New Mexico, 1994-95

As part of the National Water-Quality Assessment Program, surface-water and ground-water samples were collected in 1994 and 1995 for analysis of common constituents, nutrients, dissolved organic carbon, trace elements, radioactivity, volatile organic compounds, and pesticides to characterize surface water quality and shallow ground-water quality and to determine factors affecting water quality in the Rincon Valley, south-central New Mexico. Samples of surface water were collected from three sites on the Rio Grande and from sites on three agricultural drains in the Rincon Valley in January 1994 and 1995, April 1994, and October 1994Ground-water samples were collected in late April and early May 1994 from 30 shallow wells that were installed during the investigation. Dissolved-solids concentrations in surface water ranged from 434 to 1,510 milligrams per liter (mg/L). Dissolved-solids concentrations were smallest in water from the Rio Grande below Caballo Dam and largest in the drains. Nitrite plus nitrate concentrations ranged from less than 0.05 to 3.3 mg/L as nitrogen, and ammonia concentrations ranged from less than 0.015 to 0.33 mg/L as nitrogen in surface-water samples. Trace-element concentrations in surface water were significantly smaller than the acute-fisheries standards. One or more pesticides were detected in 34 of 37 surface-water samples. DCPA (dacthal) and metolachlor were the most commonly detected pesticides. No standards have been established for the pesticides analyzed for in this study. Dissolved-solids concentrations in shallow ground water ranged from 481 to 3,630 mg/L. All but 2 of 30 samples exceeded the secondary maximum contaminant level for dissolved solids of 500 mg/L. Water from about 73 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for sulfate, and water from about 7 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for chloride. Nitrite plus nitrate concentrations ranged from less than 0.05 to 33 mg/L as nitrogen in shallow ground water. Water from about 17 percent of the well samples exceeded the maximum contaminant level of 10 mg/L as nitrogen for nitrite plus nitrate. Trace-element concentrations in shallow ground water generally were small (1 to 10 micrograms per liter)The proposed maximum contaminant level of 20 micrograms per liter for uranium was exceeded in about 13 percent of the samples. The secondary maximum contaminant level of 300 micrograms per liter for iron was exceeded in about 17 percent of the samples and of 50 micrograms per liter for manganese was exceeded in about 83 percent of the samples. Samples from about 23 percent of the wells exceeded the maximum contaminant level of 15 picocuries per liter for gross alpha activity. One or more pesticides were detected in water from 12 of 30 wells sampled. The pesticides or pesticide metabolites diazinon, metolachlor, napropamide, p,p’-DDE, and prometon were detected in one or more samples. Metolachlor and prometon were the most commonly detected pesticides. Health advisories for the pesticides detected in shallow ground water (no maximum contaminant levels have been established for the pesticides detected) are 10 to 300 times larger than the concentrations detected. Infiltration, evaporation, and transpiration of irrigation water are important factors affecting the concentrations of common constituents in shallow ground water in the Rincon Valley. Dissolution and precipitation of minerals and mixing of shallow ground water and inflow of ground water from adjacent areas also affect the composition of shallow ground water and water in the drains. Relatively large nitrite plus nitrate concentrations in several shallow ground-water samples indicate leaching of fertilizers in some areas of the Rincon Valley. Molybdenum and uranium concentrations in part of the Rincon Valley are affected by inflow of ground water to the valley from adjacent areas. A large amount of the gross alpha activity in shallow ground water is from uranium isotopes. Gross beta activity increases with dissolved potassium, indicating that part of the dissolved gross beta activity is from potassium-40. The detection of a larger number of different pesticides in surface water than in ground water indicates that pesticides are entering surface water as runoff from fields or that the number of ground-water samples collected and the time of year that the samples were collected did not adequately represent the composition of ground water in the Rincon Valley that discharges to the drains. On the basis of pesticide concentrations detected in shallow ground water in the Rincon Valley, large amounts of the pesticides analyzed for are not leaching from land surface into ground water. There is some indication that several pesticides are leaching downward into shallow ground water (metolachlor and prometon especially); however, the concentrations detected in shallow ground water are significantly smaller than any standards or health advisories issued by the U.S. Environmental Protection Agency.

New Mexico

Surface-water-quality assessment of the upper Illinois River basin in Illinois, Indiana, and Wisconsin; project description

In 1986, the U.S. Geological Survey began a National Water-Quality Assessment program to (1) provide nationally consistent descriptions of the current status of water quality for a large, diverse, and geographically distributed part of the Nation's surface- and ground-water resources; (2) define, where possible, trends in water quality; and (3) identify and describe the relations of both status and trends in water quality to natural factors and the history of land use and land- and waste-management activities. The program is presently in a pilot phase that will test and modify, as necessary, concepts and approaches in preparation for possible full implementation of the program in the future. The upper Illinois River basin is one of four basins selected to test the concepts and approaches of the surface-water-quality element of the national program. The basin drains 10,949 square miles of Illinois, Indiana, and Wisconsin. Three principal tributaries are the Kankakee and Des Plaines Rivers that join to form the Illinois River and the Fox River. Land use is predominantly agricultural; about 75 percent of the basin is cultivated primarily for production of corn and soybeans. About 13 percent of the basin is urban area, most of which is located in the Chicago metropolitan area. The population of the basin is about 7 million. About 6 million people live in the Des Plaines River basin. Many water-quality issues in the upper Illinois River basin are related to sediment, nutrients, potentially toxic inorganic and organic constituents, and to water-management practices. Occurrence of sediment and the chemical constituents in the rivers and lakes within the basin has the potential to adversely affect the water's suitability for aquatic life, recreation, or, through the consumption of fish, human health. The upper Illinois River basin project consists of five major activities. The first activity--analysis of existing information and preparation of a report that describes recent water-quality conditions and trends--is currently underway. The second activity--fixed-station water-quality sampling at eight stations--began in April 1987 and will last at least 3 years. Water-quality data collected at these stations will be used to determine the frequency of occurrence of constituent concentrations, their annual and seasonal loads, and time trends in concentrations for a selected number of constituents. The third activity will be synoptic water-quality studies. Each study will involve sampling many sites at specific flow conditions and for selected water-quality constituents. Information gained from these studies will supplement informa tion gained from fixed-station sampling. A synoptic study of streambed sediments is tentatively planned for the summer of 1987 to describe the occurrence and distribution of trace elements in the basin. The fourth activity will consist of one or more topical subbasin or river-reach studies. The purpose of such studies is to better define certain water-quality conditions in specific areas and gain an understanding of the processes affecting the observed conditions. The fifth activity is the preparation of reports that will describe results from each of the first four activities. Quality assurance and coordination are being provided at both the national and pilot-project levels. A technical quality-assurance plan that addresses all aspects of sample collection, analysis, and reporting is being prepared at the national level. This plan will be appended as needed at the pilot-project level. A National Coordinating Work Group that functions under the auspices of the Interagency Advisory Committee on Water Data and the Advisory Committee on Water Data for Public Use has been established at the national level. A local liaison committee consisting of representatives from Federal, State, and local agencies has been established to enhance communication and to ensure that the scientific information produced by the

Open-File Report

Five-year management plan for establishing and operating NVEWS—The National Volcano Early Warning System

On March 12, 2019, Congress passed the John D. Dingell, Jr., Conservation, Management, and Recreation Act (Public Law 116–9; 133 Stat. 580), in which Title V, §5001 (43 U.S.C. 31k) authorized the establishment of the National Volcano Early Warning and Monitoring System (NVEWS) within the U.S. Geological Survey (USGS). Conceived by the USGS Volcano Hazards Program in 2005, NVEWS is designed to be a proactive, fully integrated national-scale volcano monitoring system to ensure that the 161 potentially active volcanoes in the United States and its territories are monitored at levels commensurate with the threat they pose. The core of this report is the first USGS NVEWS five-year management plan, which was presented to Congress on March 12, 2020, and which details the principal elements of NVEWS that will be developed over the next five years, pending sufficient funding. These elements are improvements and enhancements to the monitoring network, a National Volcano Data Center, an external grants activity, an Advisory Committee, an Implementation Committee, and partnerships, with estimated cost projections and annual milestones.

Northern Mariana Islands

Occurrence and concentrations of selected trace elements and halogenated organic compounds in stream sediments and potential sources of polychlorinated biphenyls, Leon Creek, San Antonio, Texas, 2012–14

The Texas Department of State Health Services issued fish consumption advisories in 2003 and 2010 for Leon Creek in San Antonio, Texas, based on elevated concentrations of polychlorinated biphenyls (PCBs) in fish tissues. The U.S. Geological Survey (USGS) measured elevated PCB concentrations in stream-sediment samples collected during 2007&ndash;9 from Leon Creek at Lackland Air Force Base (now known as Joint Base San Antonio-Lackland; the sampling site at this base is hereinafter referred to as the &ldquo;Joint Base site&rdquo;) and sites on Leon Creek downstream from the base. This report describes the occurrence and concentrations of selected trace elements and halogenated organic compounds (pesticides, flame retardants, and PCBs) and potential sources of PCBs in stream-sediment samples collected from four sites on Leon Creek during 2012&ndash;14. In downstream order, sediment samples were collected from Leon Creek at northwest Interstate Highway 410 (Loop 410), Rodriguez Park, Morey Road, and Joint Base. The USGS periodically collected streambed-sediment samples during low flow and suspended-sediment samples during high flow. Trace element concentrations were low compared to the consensus-based sediment-quality guidelines (SQGs) for the threshold effect concentration (TEC) and probable effect concentration (PEC). Adverse effects to benthic biota are not expected at concentrations less than the TEC and are expected at concentrations greater than the PEC. No trace element concentrations were greater than the PEC in any of the samples. Trace element concentrations were greatest at the Morey Road and Joint Base sites and exceeded the TECs by 41 and 27 percent, respectively. Trace element concentrations were lowest at the Rodriguez Park and Loop 410 sites and exceeded the TECs by 18 and 14 percent, respectively. Pesticides that have been banned for several decades are commonly detected in Leon Creek stream sediments, particularly the chlordane compounds. Chlordane compounds were detected in 84 percent of the samples and at every sample collection site. The samples collected from the Rodriguez Park site had the most pesticide compounds detected. Only samples collected from the Joint Base site had dichlorodiphenyldichloroethane (DDD), dichlorodiphenyldichloroethylene (DDE), or dichlorodiphenyltrichloroethane (DDT) concentrations greater than the TEC, and a few were also greater than the PEC. Flame retardants were found at every site on Leon Creek where stream sediments were collected; however, a few compounds were frequently detected in the laboratory reagent blanks so their detections in the environmental samples may not be from local sources. Consensus-based SQGs were not available for flame retardants so samples were compared to Environment Canada Federal Environmental Quality Guidelines (FEQGs). The concentrations of flame retardants generally were greater in the suspended-sediment samples than the streambed-sediment samples and greater than the FEQGs in many cases. Eighteen PCB congeners were quantified in the sediment samples collected from Leon Creek. The samples collected from the Joint Base site had the most frequent PCB congener detections. Total PCB concentrations, computed as the sum of the 18 congeners by using the Kaplan-Meier method for left-censored environmental data, were much smaller than the TEC of 59.8 micrograms per kilogram (&mu;g/kg). When detected, the concentrations of total PCBs in the stream-sediment samples collected from Leon Creek during 2012&ndash;14 ranged from an estimated 0.2 to 8.7 &mu;g/kg. Sediment samples collected from Leon Creek by the USGS during 2007&ndash;9 and 2012&ndash;14 at a total of eight sites following identical field and laboratory methods were evaluated to determine if potential PCB sources could be identified. Total PCB concentrations in the sediment samples collected upstream from the Joint Base site were low or nondetections; while concentrations in the samples collected on and downstream from the Joint Base site were greater. Congeners 180 and 138 constituted the greatest proportion of the PCB mixture in samples collected upstream from, on, and downstream from the Joint Base site. Upstream from the Joint Base site, congeners 180 and 138 constituted 50 percent and 35 percent respectively of the PCBs congeners found in the samples. On and downstream from the Joint Base site, congeners 180 and 138 constituted 80 percent and 13 percent respectively of the PCBs congeners found in the samples. Chi-square (C2) tests also indicate that samples collected from the Loop 410 site were statistically different from samples collected from the Joint Base site and sites downstream. The PCB congener pattern in the Leon Creek samples is most like the congener mixture in Aroclor 1260, which is chemically similar to the PCBs detected in the fish samples that resulted in the 2003 fish consumption advisory.

Texas

A statistical model and national data set for partioning fish-tissue mercury concentration variation between spatiotemporal and sample characteristic effects

Many Federal, Tribal, State, and local agencies monitor mercury in fish-tissue samples to identify sites with elevated fish-tissue mercury (fish-mercury) concentrations, track changes in fish-mercury concentrations over time, and produce fish-consumption advisories. Interpretation of such monitoring data commonly is impeded by difficulties in separating the effects of sample characteristics (species, tissues sampled, and sizes of fish) from the effects of spatial and temporal trends on fish-mercury concentrations. Without such a separation, variation in fish-mercury concentrations due to differences in the characteristics of samples collected over time or across space can be misattributed to temporal or spatial trends; and/or actual trends in fish-mercury concentration can be misattributed to differences in sample characteristics. This report describes a statistical model and national data set (31,813 samples) for calibrating the aforementioned statistical model that can separate spatiotemporal and sample characteristic effects in fish-mercury concentration data. This model could be useful for evaluating spatial and temporal trends in fishmercury concentrations and developing fish-consumption advisories. The observed fish-mercury concentration data and model predictions can be accessed, displayed geospatially, and downloaded via the World Wide Web (http://emmma.usgs.gov). This report and the associated web site may assist in the interpretation of large amounts of data from widespread fishmercury monitoring efforts.

Scientific Investigations Report

Geologic and hydrogeologic framework of the Espanola basin -- Proceedings of the 4th annual Espanola Basin Workshop, Santa Fe, New Mexico, March 1-3, 2005

This report presents abstracts of technical studies that pertain to the hydrogeologic framework of the This report presents abstracts of technical studies that pertain to the hydrogeologic framework of the Española basin, a major subbasin of the Cenozoic Rio Grande rift. Sediments and interbedded volcanic rocks that fill the Española basin comprise an aquifer system that is an important source of water for many residents of the basin, including people in the cities of Santa Fe, Española, and Los Alamos as well as Native Americans in eleven Pueblos. The abstracts describe results of technical studies that were presented either as poster exhibits or oral presentations at the forth-annual Española basin workshop, held March 1-2 of 2005 in Santa Fe, New Mexico. The principal goal of this workshop was to share information about ongoing studies. The Española basin workshop was hosted by the Española basin technical advisory group (EBTAG) and sponsored by the U.S. Geological Survey, the New Mexico Bureau of Geology and Mineral Resources, and both the Water Research Technical Assistance Office and the Groundwater Protection Program of Los Alamos National Laboratory. Abstracts in this report have been grouped into six information themes: Basic Water Data, Water Quality and Water Chemistry, Water Balance and Stream/Aquifer Interaction, Data Integration and Hydrologic Model Testing, Three-Dimensional Hydrogeological Architecture, and Geologic Framework. Taken together, the abstracts in this report provide a view of the current status of hydrogeologic research within the Española basin. , a major subbasin of the Cenozoic Rio Grande rift. Sediments and interbedded volcanic rocks that fill the Española basin comprise an aquifer system that is an important source of water for many residents of the basin, including people in the cities of Santa Fe, Española, and Los Alamos as well as Native Americans in eleven Pueblos. The abstracts describe results of technical studies that were presented either as poster exhibits or oral presentations at the forth-annual Española basin workshop, held March 1-2 of 2005 in Santa Fe, New Mexico. The principal goal of this workshop was to share information about ongoing studies. The Española basin workshop was hosted by the Española basin technical advisory group (EBTAG) and sponsored by the U.S. Geological Survey, the New Mexico Bureau of Geology and Mineral Resources, and both the Water Research Technical Assistance Office and the Groundwater Protection Program of Los Alamos National Laboratory. Abstracts in this report have been grouped into six information themes: Basic Water Data, Water Quality and Water Chemistry, Water Balance and Stream/Aquifer Interaction, Data Integration and Hydrologic Model Testing, Three-Dimensional Hydrogeological Architecture, and Geologic Framework. Taken together, the abstracts in this report provide a view of the current status of hydrogeologic research within the Española basin.

New Mexico

Ground water resources of the Mille Lacs Lake area, east-central Minnesota

The Mille Lacs Lake study area is a 960 mi 2 area containing the ground-water and surface-water drainages to both Mille Lacs Lake and the first 12 miles of the Rum River. Within this study area, available ground water occurs in saturated, overlapping, discontinuous, partially-connected, glacially-deposited (hereinafter, glacial) aquifers and in bedrock aquifers. No extensive glacial aquifer could be delineated. Surficial aquifers generally are less than 30 feet thick, but may exceed 78 feet. Lake Onamia is hydraulically connected with surficial aquifers on its north and south sides. Ground water enters Lake Onamia from an adjacent surficial aquifer with a hydraulic head of 1.56 feet near its eastern shore. Glacial aquifers buried beneath till form the uppermost confined (hereinafter, buried) aquifers and generally are from 3 to 15 feet thick, but may be as much as 118 feet thick. These buried aquifers generally occur beneath 10 to 60 feet of till and clay, but it may be as thick as 208 feet. Individual aquifers can be partially buried by till and therefore may contain surficial and buried areas. Most buried aquifers are isolated or only partially connected to other aquifers. Recharge water moves horizontally and vertically through other aquifers and through confining units to reach these buried aquifers. Discharge from these aquifers is through well withdrawals, flow to surface-water bodies, and leakage to other aquifers. Buried aquifers may yield as much as 500 gallons per minute in some locations. In most areas, the specific capacity of these aquifers is less than 1 gallon per minute per foot but may reach 41.6 gallons per minute per foot. Ground water from all aquifers is of the calcium magnesium bicarbonate type. Iron, manganese, and sodium in this ground water frequently exceeded U.S. Environmental Protection Agency drinking water standards and health advisories. The sodium health advisory was exceeded in 15 percent of samples.

Minnesota