The quality of water accessed by domestic wells (here referred to as domestic groundwater resources) in the San Joaquin Valley Kern County subbasin (basin number 5-022.14) was assessed as part of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project (GAMA-PBP), in cooperation with the California State Water Resources Control Board. Kern County is at the southern end of the San Joaquin Valley in California, and about 30,000 residents are estimated to use privately owned domestic wells for drinking water. Domestic wells typically draw from shallower parts of the aquifer system than public-supply wells and can be more vulnerable to effects from surface activities. Kern County is host to a highly productive agricultural industry, with Bakersfield as the main urban center. The Kern River runs through Bakersfield from the southern Sierra Nevada and intersects the Kern Water Bank, one of the largest groundwater banking operations in California, at the Kern River Intertie. The section of the Kern River running through the Kern Water Bank is dry most years. Kern County also encompasses some of the most productive oil and gas basins in California, with extensive underground and surface disposal of oil-field wastewater.
This study was based on data collected from 33 sites sampled by the U.S. Geological Survey for the GAMA-PBP in 2022. To provide context for the water quality assessment, measured concentrations were compared to regulatory and non-regulatory health-based and aesthetic benchmarks. A grid-based method was used to estimate the proportions of the groundwater resources used for domestic-supply wells that have water-quality constituents below (low relative concentration), approaching (moderate relative concentration), or above (high relative concentration) benchmark concentrations. At least one measured constituent with a regulatory benchmark was categorized as having a high relative concentration in 72 percent of the aquifer area used for domestic groundwater resources. Inorganic constituents were detected at high concentrations in 45 percent of the domestic groundwater resources, and the constituents detected above regulatory benchmarks were arsenic, nitrate, and uranium. At least one organic constituent was detected at high concentrations in 41 percent of the domestic groundwater resources, and the constituents exceeding regulatory benchmarks were the fumigants 1,2,3-trichloropropane (1,2,3-TCP), 1,2-dibromo-3-chloropropane (dibromochloropropane [DBCP]), 1,2-dibromoethane (EDB), and the per-and polyfluoroalkyl substance (PFAS) perfluorooctanesulfonate. The disinfection by-product chloroform, the fumigant 1,2-dichloropropane, the herbicides atrazine and hexazinone, and the herbicide degradates 2-chloro-6-ethylamino-4-amino-s-triazine, 2-chloro-4,6-diamino-s-triazine, 4-hydroxychlorothalonil, and metolachlor sulfonic acid were detected in more than 10 percent of domestic groundwater resources, but concentrations did not exceed regulatory benchmarks.
Land use, groundwater age (fraction of modern water and mean age), and geochemical environment (oxic or anoxic conditions, pH, alkalinity) were associated with the distribution of high relative concentrations of inorganic and organic constituents. Young, oxygenated water is recharged along the Kern River and adjacent recharge ponds, or as irrigation water in the agricultural areas. High concentrations of nitrate and volatile organic compounds occurred in the oxic water in urban and agricultural areas. The fumigants 1,2,3-TCP, DBCP, and EDB were reported throughout the agricultural areas, whereas chloroform, tetrachloroethene, and PFAS were associated with urban land use. High uranium concentrations were associated with young, modern groundwater in agricultural areas with low pH and high bicarbonate. Total dissolved solids increased with distance from the Kern River, as the contributions of fresh, oxic water decreased. High concentrations of arsenic were present in older anoxic or alkaline groundwater away from areas of recharge. Overall, groundwater age, redox conditions, and the source of recharge as a result of different land uses contribute to large aquifer-scale portions of domestic groundwater resources that exceed health-based benchmarks for nitrate, uranium, and fumigant concentrations.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20265012","collaboration":"Prepared in cooperation with the California State Water Resources Control Board","usgsCitation":"Harkness, J.S., Faulkner, K.E., and Jurgens, B.C., 2026, Status and understanding of groundwater quality\nin the San Joaquin Valley Kern County subbasin domestic- supply aquifer study unit, 2022—California\nGAMA Priority Basin Project: U.S. Geological Survey Scientific Investigations Report 2026–5012, 53 p.,\nhttps://doi.org/10.3133/sir20265012.","productDescription":"Report: x, 53 p.; 3 Data Releases","numberOfPages":"53","onlineOnly":"Y","additionalOnlineFiles":"N","ipdsId":"IP-169250","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":504430,"rank":8,"type":{"id":30,"text":"Data Release"},"url":"https://doi.org/10.5066/P13WQA8P","text":"USGS data release","linkHelpText":"Potential explanatory variables for groundwater quality in the San Joaquin Valley Kern County subbasin domestic well study unit, 2022"},{"id":504429,"rank":7,"type":{"id":30,"text":"Data Release"},"url":"https://doi.org/10.5066/P13ISEGA","text":"USGS data release","linkHelpText":"Data for assessing the susceptibility of groundwater used for domestic- supply, California"},{"id":504428,"rank":6,"type":{"id":30,"text":"Data Release"},"url":"https://doi.org/10.5066/P9GGNIQI","text":"USGS data release","linkHelpText":"Groundwater- quality data in the Kern County Domestic- Supply Aquifer Study Unit, 2022—Results from the California GAMA Priority Basin Project"},{"id":504425,"rank":3,"type":{"id":39,"text":"HTML Document"},"url":"https://pubs.usgs.gov/publication/sir20265012/full","linkFileType":{"id":5,"text":"html"},"description":"OFR 2026-5012 HTML"},{"id":504424,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2026/5012/sir20265012.pdf","text":"Report","size":"37.5 MB","linkFileType":{"id":1,"text":"pdf"},"description":"OFR 2026-5012 PDF"},{"id":504426,"rank":4,"type":{"id":31,"text":"Publication XML"},"url":"https://pubs.usgs.gov/sir/2026/5012/sir20265012.XML","description":"OFR 2026-5012 XML"},{"id":504423,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2026/5012/coverthb.jpg"},{"id":504427,"rank":5,"type":{"id":34,"text":"Image Folder"},"url":"https://pubs.usgs.gov/sir/2026/5012/images"}],"contact":"Director, California Water Science Center
U.S. Geological Survey
6000 J Street, Placer Hall
Sacramento, California 95819
Acknowledgments
Abstract
Introduction
Hydrogeologic Setting
Methods
Status of Groundwater Quality
Factors that Affect Groundwater Quality
Summary
References Cited
Chlorinated solvents, including trichloroethene (TCE) and other chlorinated volatile organic compounds (cVOCs), are widespread contaminants that can be treated by bioremediation approaches that enhance anaerobic reductive dechlorination. Reductive dechlorination can be enhanced either through the addition of an electron donor (biostimulation) or the addition of a known dechlorinating culture (bioaugmentation) along with an electron donor. Although bioremediation has been applied at many TCE-contaminated groundwater sites, application in source zones at sites where residual dense nonaqueous phase liquid (DNAPL) is present is more limited. In this study, laboratory and field treatability tests were completed to evaluate the potential application of anaerobic bioremediation for a shallow groundwater plume containing TCE in a perched alluvial aquifer at Site K, former Twin Cities Army Ammunition Plant, Arden Hills, Minnesota, which was on the National Priorities List as the New Brighton/Arden Hills Superfund site until 2019. In addition to the presence of residual DNAPL at the site, temporal variability in groundwater flow directions and input of oxygenated recharge were possible complicating factors for the application of enhanced anaerobic biodegradation in the shallow plume. The Site K plume extends beneath the footprint of Building 103, which was demolished in 2006, and soil excavations to a maximum depth of 6 feet (ft) below ground surface in 2014 were known to leave some deeper contaminated soil in place in the TCE source area. Groundwater treatment at the site, formalized as part of the 1997 Record of Decision, has been in operation since 1986 and consists of an extraction trench at the downgradient edge of the plume to collect groundwater, which is then pumped to an on-site air stripper. Groundwater concentrations in the plume have been relatively stable since treatment began, indicating a continued source of TCE in the aquifer. The desire for a destructive remedy that would enhance the removal of cVOCs in the aquifer at Site K and shorten the remediation timeframe led the U.S. Army to request that the U.S. Geological Survey conduct a groundwater treatability study to assess bioremediation. This report describes the U.S. Geological Survey bioremediation treatability study conducted during 2020–22, including pre-design site characterization to assist in formulating the bioremediation approach, laboratory experiments to support the design of the field pilot test, and implementation and 1-year performance monitoring results for the pilot test.
Pre-design site characterization included the collection of soil cores for cVOC analysis and lithologic descriptions and the re-installment of three wells to obtain hydrologic measurements and initial groundwater chemistry. Relatively flat head gradients were measured at the site, and substantial decreases in water-level elevations occurred from spring to summer (May–July 2021). Continuous water-level monitoring indicated a rapid response to precipitation. Groundwater flow velocities were consistently less than 0.5 foot per day, and the pilot bioremediation test was therefore designed with short lateral distances (about 5 ft) between injection and individual monitoring points. Soil analyses confirmed that high volatile organic compound contamination was left in place in the source area. The highest concentrations were near or in clay at the base of the perched aquifer. Concentrations of cVOCs measured in the replaced wells were consistent with historical data and had a maximum TCE concentration of 57,700 micrograms per liter (μg/L), indicative of nearby residual DNAPL based on the general rule of observed concentrations exceeding 1 percent of solubility. The primary TCE daughter product detected was 1,2-cis-dichloroethene (cisDCE), which indicated limited reductive dechlorination in the plume. Groundwater in both the source and downgradient areas was relatively reducing during the pre-design characterization, particularly in the source area where methane concentrations greater than 400 μg/L were measured.
Initial laboratory tests conducted using native aquifer microorganisms from the three replacement wells showed that anaerobic TCE biodegradation rates were low when biostimulated with the addition of sodium lactate as an electron donor, also known as a carbon donor, and resulted in the production of only cisDCE. Addition of a known dechlorinating culture, WBC-2, however, resulted in rapid biodegradation and production of ethene, verifying complete reductive dechlorination of TCE. Microcosms constructed with aquifer soil collected from the site were used to evaluate other electron donors besides lactate to support reductive dechlorination by WBC-2, including corn syrup as an alternative fast-release compound and whey, soy-based vegetable oil, and 3-D Microemulsion (Regenesis, San Clemente, California) as slow-release compounds. First-order rate constants for total organic chlorine removal in these WBC-2 amended microcosms were greatest with either lactate or vegetable oil as the donor, ranging between 0.061 and 0.047 per day or corresponding half-lives of 11–15 days. Testing of commercial products in other WBC-2-bioaugmented microcosms led to selection for the field pilot test of an emulsified vegetable oil product that also contained some sodium lactate as a fast-release donor. Delaying the addition of WBC-2 relative to the donor in the microcosms resulted in the most rapid overall biodegradation rates.
The selected design for the pilot test utilized three separate test plots, each about 30-ft wide and 60-ft long: plots GS1 and GS2 in the source area of the plume and plot GS3 in the downgradient area of the plume near the excavation trench. Each test plot had one injection well, one monitoring well upgradient from the injection point, and 12 surrounding monitoring wells in a grid to capture variable groundwater flow directions. Donor injections, which included a bromide tracer, were completed in October 2021, immediately following baseline sampling, and the WBC-2 culture was injected about 40 days later, between November 30 and December 2, 2021. Performance monitoring conducted until December 2022 included hydrologic measurements and analyses of cVOCs, redox-sensitive constituents, dissolved organic carbon, bromide, volatile fatty acids, compound-specific carbon isotopes, and microbial communities.
The biogeochemical data collected during the pilot tests in the three treatment plots showed that enhanced, complete reductive dechlorination of cVOCs in the groundwater was achieved in the GS1 and GS3 plots. In contrast, evidence of distribution of the injected amendments and subsequent biodegradation was limited in GS2, which was in an area of more heterogeneous soil lithology and low water table elevations. The molar composition of volatile organic compounds in the GS1 and GS3 plots was dominated by ethene in wells that were reached by the injected amendments by the end of the monitoring period. In the GS1 and GS3 plots, similar patterns were observed of cVOC concentrations decreasing to near detection levels, or below, at some wells sampled in July and October 2022, whereas ethene became dominant and indicated sustained complete reductive dechlorination. Baseline cVOC concentrations were more than a factor of 10 higher in the groundwater in the GS1 plot than in GS3, but no apparent inhibition of complete dechlorination occurred. As expected from the initial pre-design site data and the laboratory experiments, enhanced dissolution of residual DNAPL coupled to biodegradation was evident in the GS1 plot, where a marked increase in dichloroethene (DCE) above the initial baseline and upgradient TCE and DCE concentrations occurred. DCE concentrations subsequently declined where DNAPL dissolution was evident, concurrent with production of vinyl chloride and then predominantly ethene. Thus, overall biodegradation rates outpaced the DNAPL dissolution and desorption and DCE production in the source area. This success in complete degradation to predominantly ethene was achieved even in areas where the DCE concentrations reached a maximum of about 30,000 μg/L. Compound specific isotope analysis of carbon in TCE, cisDCE, trans-1,2-dichloroethene, and vinyl chloride was conducted to provide another line of evidence of the occurrence and extent of anaerobic biodegradation. Along a flow path in each plot that was affected by the injected amendments, carbon isotopes in the TCE and daughter cVOCs in the groundwater became isotopically heavier, indicating biodegradation.
Enhanced biodegradation rates calculated from the field tests in GS1 and GS3 showed half-lives of 36.9–75.3 days for DCE degradation and 9.48–38.5 days for ethene production. Notably, these ethene production rates calculated from the field tests are consistent with the results of WBC-2-bioaugmented microcosms amended with either lactate or vegetable oil, which had half-lives for total organic chlorine removal that ranged from 11 to 15 days. These rates indicated rapid enhanced biodegradation, which is promising for application of a full-scale bioremediation remedy. Ultimately, however, the mass of residual or sorbed TCE in the aquifer that remains accessible for dissolution and biodegradation would likely control the time required for a full-scale bioremediation effort to achieve performance goals for TCE and cisDCE specified in the Record of Decision for Site K.
The field pilot tests showed that the relatively low hydraulic head gradients and temporal changes in groundwater flow directions in the shallow aquifer would add complexity to a full-scale bioremediation effort. The radius of influence (ROI) at GS1 and GS3 (16.3 ft and 12.7 ft, respectively) were close to the design ROI of 15 ft. The estimated ROI at GS2 was about four times the design ROI, but may be less reliable at this location owing to groundwater flow direction. In addition, the low temperatures following WBC-2 injection in late November to early December 2021, in combination with the low hydraulic head gradients, were probably major factors in the delay observed before the onset of enhanced biodegradation following injection of the culture. Additional test injections could be beneficial to optimize the timing of donor and culture injections with the variable temperatures and hydraulic head in the shallow aquifer.
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The 2018 eruption of Kīlauea volcano in its Lower East Rift Zone began with the discharge of evolved high-Ti basalt as weak lava fountains and short, slow-moving lava flows. The lavas were quickly geochemically recognized as being derived from magmas stored within the rift zone and remobilized by a new intrusion, a sequence that is common at Kīlauea. This initial phase of the 2018 eruption, referred to as phase 1a, lasted for 6 days and was followed by extrusion of mixed magma after a 3-day pause. Even though remobilization of older rift zone magmas is common within Kīlauea’s rift zones, it is difficult to determine which past intrusion(s) may have initially emplaced those stored magmas. This difficulty stems from the tendency for Kīlauea magmas to follow very similar differentiation paths without significant variations in major, minor, or even trace element chemistry. We investigate possible magma sources for the lavas erupted during phase 1a of the 2018 eruption using whole-rock, mineral, and glass major and trace element compositions from historical East Rift Zone eruptions with adjacent fissures. We consider two primary hypotheses for the phase 1a source: magmas associated with the 1955 Lower East Rift Zone eruption or the nine eruptions in the Middle and Upper East Rift Zone during the 1960s. Our results suggest that magma associated with the earliest phases of Kīlauea’s 1955 eruption was the most likely source of the 2018 phase 1a remobilized magma. We determine volatile saturation pressures from melt inclusion chemistry and find similar storage depths for the 2018 phase 1a and early 1955 magmas. The phase 1a and early 1955 lavas are nearly indistinguishable in all of the compositional criteria considered, implying that the leftover 1955 magma body barely cooled and differentiated in the 63 years between eruptions (cooling rates of ~0.1 °C/year). This study sheds light on the potential for protracted storage of eruptible magmas in rift zones at Kīlauea, and highlights some of the challenges and solutions to identifying genetic relationships between magmas at Kīlauea.
","language":"English","publisher":"Oxford Academic","doi":"10.1093/petrology/egag008","usgsCitation":"Gallo, R., Barreau, L., Shea, T., Cluzel, N., Russo, C., Pietruszka, A., Nelson, W., Lerner, A., Wallace, P.J., and Gansecki, C., 2026, Magmatic source of the opening phase of Kīlauea’s 2018 Lower East Rift Zone eruption: Journal of Petrology, v. 67, no. 2, egag008, https://doi.org/10.1093/petrology/egag008.","productDescription":"egag008","ipdsId":"IP-179268","costCenters":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"links":[{"id":500723,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Hawaii","otherGeospatial":"Kīlauea volcano","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -155.2962677550091,\n 19.48026991999376\n ],\n [\n -155.2962677550091,\n 19.388465727050132\n ],\n [\n -155.18401212172833,\n 19.388465727050132\n ],\n [\n -155.18401212172833,\n 19.48026991999376\n ],\n [\n -155.2962677550091,\n 19.48026991999376\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"67","issue":"2","noUsgsAuthors":false,"publicationDate":"2026-01-29","publicationStatus":"PW","contributors":{"authors":[{"text":"Gallo, Rose","contributorId":367112,"corporation":false,"usgs":false,"family":"Gallo","given":"Rose","affiliations":[{"id":39163,"text":"University of Hawaii - 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2026 - Assessing future hydrologic extremes using an integrated hydrology and river operations model in the Russian River watershed","interactions":[],"lastModifiedDate":"2026-01-09T17:31:50.365144","indexId":"70273363","displayToPublicDate":"2026-01-06T11:26:38","publicationYear":"2026","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3823,"text":"Journal of Hydrology: Regional Studies","active":true,"publicationSubtype":{"id":10}},"title":"Assessing future hydrologic extremes using an integrated hydrology and river operations model in the Russian River watershed","docAbstract":"At many petroleum hydrocarbon spill sites, residual spilled product forms a long-term source of groundwater contamination. The phrase source zone natural depletion is used to refer to the mass loss rates. Overall mass lost under environmental conditions was analyzed using conservative biomarker concentrations for a 1979 oil spill in northern Minnesota, USA. After 40–41 years, an average of 50% of the mass was lost with values ranging from 22% to 57% depending on location. It is also important to understand the composition changes in the source. To understand controls on the losses of individual compounds, concentrations of volatile hydrocarbons in oil samples were compared with aqueous solubilities, and pore-space oil saturations. The results of the comparison show that losses of the oil compounds were controlled by pore-space oil saturations, solubility, and susceptibility to degradation under methanogenic conditions. Compounds that degrade under methanogenic conditions, including toluene, o-xylene, and n-alkanes are more depleted compared to benzene, ethylbenzene, and m- and p-xylene for which losses are dominated by dissolution. These rates and compound-specific behaviors form a foundation for improved modeling approaches and risk analyses.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2025WR041964","usgsCitation":"Bekins, B., and Herkelrath, W., 2026, Natural source zone depletion of crude oil in the subsurface: Processes controlling mass losses of individual compounds: Water Resources Research, v. 62, no. 1, e2025WR041964, 19 p., https://doi.org/10.1029/2025WR041964.","productDescription":"e2025WR041964, 19 p.","ipdsId":"IP-139177","costCenters":[{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"links":[{"id":498472,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2025wr041964","text":"Publisher Index Page"},{"id":498361,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Bemidji crude oil site","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -95.0916,\n 47.5742\n ],\n [\n -95.0916,\n 47.5733\n ],\n [\n -95.0895,\n 47.5733\n ],\n [\n -95.0895,\n 47.5742\n ],\n [\n -95.0916,\n 47.5742\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"62","issue":"1","noUsgsAuthors":false,"publicationDate":"2025-12-30","publicationStatus":"PW","contributors":{"authors":[{"text":"Bekins, Barbara 0000-0002-1411-6018 babekins@usgs.gov","orcid":"https://orcid.org/0000-0002-1411-6018","contributorId":139407,"corporation":false,"usgs":true,"family":"Bekins","given":"Barbara","email":"babekins@usgs.gov","affiliations":[{"id":451,"text":"National Water Quality Assessment Program","active":true,"usgs":true},{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":953297,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Herkelrath, William 0000-0002-6149-5524","orcid":"https://orcid.org/0000-0002-6149-5524","contributorId":210576,"corporation":false,"usgs":true,"family":"Herkelrath","given":"William","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":953298,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70275624,"text":"70275624 - 2025 - Source(s) of the smooth Caloris exterior plains on Mercury: Mapping, remote analyses, and scenarios for future testing with BepiColombo data","interactions":[],"lastModifiedDate":"2026-05-06T14:06:34.780928","indexId":"70275624","displayToPublicDate":"2025-12-19T00:00:00","publicationYear":"2025","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3250,"text":"Remote Sensing","active":true,"publicationSubtype":{"id":10}},"title":"Source(s) of the smooth Caloris exterior plains on Mercury: Mapping, remote analyses, and scenarios for future testing with BepiColombo data","docAbstract":"Mercury hosts widespread smooth plains that are concentrated in the Caloris impact basin, in an annulus surrounding the Caloris basin, and in the adjacent northern smooth plains. The origins of these smooth plains are uncertain, although prior work suggests these plains in the northwestern Caloris annulus might reflect volcanic activity, impact ejecta, or a combination of the two. Deciphering the timing and mode of emplacement of these plains would provide a critical constraint on regional late-stage volcanism or impact effects. In this work, the region northwest of Caloris was investigated using geomorphological and color-based mapping, crater counting techniques, and spectral analyses with the goal of placing constraints on the source of the observed units and identifying the primary emplacement mechanism. Mapping and spectral analyses confirm previous findings of two distinct, yet intermingled, units within these plains, each with similar crater count model ages that postdate the formation of the Caloris impact basin. Mapping, spectra analysis, ages, and the identification of potential flow pathways are more consistent with a predominantly volcanic origin for the smooth plains materials, although these data do not rule out contributions from impact ejecta or impact melt. We propose several hypothetical scenarios, including post-emplacement modification by near-surface volatiles, to explain these observations and clarify the emplacement mechanism for these specific smooth plains regions. Further observations from the BepiColombo mission should provide data to potentially address the outstanding questions from this work.
","language":"English","publisher":"MDPI","doi":"10.3390/rs18010019","usgsCitation":"Golder, K.G., Thompson, B.J., Ostrach, L.R., Burr, D.M., Emery, J.P., and Hiesinger, H., 2025, Source(s) of the smooth Caloris exterior plains on Mercury: Mapping, remote analyses, and scenarios for future testing with BepiColombo data: Remote Sensing, v. 18, no. 1, 19, 27 p., https://doi.org/10.3390/rs18010019.","productDescription":"19, 27 p.","ipdsId":"IP-184196","costCenters":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"links":[{"id":504199,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.3390/rs18010019","text":"Publisher Index Page"},{"id":504000,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mercury","volume":"18","issue":"1","noUsgsAuthors":false,"publicationDate":"2025-12-20","publicationStatus":"PW","contributors":{"authors":[{"text":"Golder, Keenan G.","contributorId":371156,"corporation":false,"usgs":false,"family":"Golder","given":"Keenan","middleInitial":"G.","affiliations":[{"id":88105,"text":"Roane State Community College","active":true,"usgs":false}],"preferred":false,"id":961129,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Thompson, Bradley J.","contributorId":371157,"corporation":false,"usgs":false,"family":"Thompson","given":"Bradley","middleInitial":"J.","affiliations":[{"id":63836,"text":"University of Tennessee, Knoxville","active":true,"usgs":false}],"preferred":false,"id":961130,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ostrach, Lillian R. 0000-0002-3107-7321 lostrach@usgs.gov","orcid":"https://orcid.org/0000-0002-3107-7321","contributorId":193078,"corporation":false,"usgs":true,"family":"Ostrach","given":"Lillian","email":"lostrach@usgs.gov","middleInitial":"R.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":961131,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Burr, Devon M.","contributorId":370803,"corporation":false,"usgs":false,"family":"Burr","given":"Devon","middleInitial":"M.","affiliations":[{"id":12698,"text":"Northern Arizona University","active":true,"usgs":false}],"preferred":false,"id":961132,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Emery, Joshua P.","contributorId":370806,"corporation":false,"usgs":false,"family":"Emery","given":"Joshua","middleInitial":"P.","affiliations":[{"id":12698,"text":"Northern Arizona University","active":true,"usgs":false}],"preferred":false,"id":961133,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Hiesinger, Harold","contributorId":238485,"corporation":false,"usgs":false,"family":"Hiesinger","given":"Harold","affiliations":[],"preferred":false,"id":961134,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70273125,"text":"70273125 - 2025 - The anatomy and lethality of the Siberian Traps large igneous province","interactions":[],"lastModifiedDate":"2025-12-16T14:44:45.356438","indexId":"70273125","displayToPublicDate":"2025-12-16T08:37:40","publicationYear":"2025","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":806,"text":"Annual Review of Earth and Planetary Sciences","active":true,"publicationSubtype":{"id":10}},"title":"The anatomy and lethality of the Siberian Traps large igneous province","docAbstract":"Emplacement of the Siberian Traps large igneous province (LIP) around 252 Ma coincided with the most profound environmental disruption of the past 500 million years. The enormous volume of the Siberian Traps, its ability to generate greenhouse gases and other volatiles, and a temporal coincidence with extinction all suggest a causal link. Patterns of marine and terrestrial extinction/recovery are consistent with environmental stresses potentially triggered by the Siberian Traps. However, the nature of causal links between the LIP and mass extinction remains enigmatic. Understanding the origins, anatomy, and forcing potential of the Siberian Traps LIP and the spatiotemporal patterns of resulting stresses represents a critical counterpart to high-resolution fossil and proxy records of Permian–Triassic environmental and biotic shifts. This review provides a summary of recent advances and key questions regarding the Siberian Traps in an effort to illuminate what combination of factors made the Siberian Traps a uniquely deadly LIP.
The Lee Acres Landfill and Giant Bloomfield Refinery are adjacent properties near the City of Farmington, New Mexico, each having undergone monitoring and remediation related to historical site activities. At the landfill, site cleanup has included the installation of a capillary barrier over former liquid waste lagoons and periodic monitoring of groundwater elevations and groundwater quality. At the refinery, remediation has focused on several petrochemical and crude oil release areas and included soil excavation, groundwater treatment, and regular monitoring of groundwater elevations and quality. Groundwater at both sites has higher concentrations of volatile organic compounds and trace metals than background aquifer concentrations. In 2022, the U.S. Geological Survey compiled the Lee Acres-Giant Bloomfield Refinery Database (LAGBRD), which contains publicly available groundwater-elevation data and organic and inorganic groundwater-quality data from both sites, spanning from 1985 to 2020. Data from the LAGBRD and precipitation data from other sources were used to better understand the cause of relatively high manganese concentrations observed in some groundwater wells at the site through comparison of groundwater chemistry to chemical end members, interpretation of spatial and temporal patterns in the groundwater chemistry, and interpretation of groundwater flow properties. In this study, elevated chloride concentrations in groundwater downgradient from the landfill have been attributed to landfill leachate based on the temporal and spatial variability of chloride concentrations and chloride-to-bromide ratios. Installation of a capillary barrier and surface-water runoff controls at the landfill in 2005 appears to have altered infiltration patterns at that site, resulting in a decrease in chloride at some wells but an increase in chloride and dissolved manganese at others. The timing and relation among groundwater elevation, chloride concentration, and manganese concentration suggest that leachate stored in the vadose zone provides a continued source of contamination to groundwater.
Director, New Mexico Water Science Center
U.S. Geological Survey
6700 Edith Blvd. NE
Albuquerque, NM 87113
Contact Us- USGS Publications Warehouse
","tableOfContents":"More than 2 million Californians rely on groundwater from domestic wells for drinking-water supply. This report summarizes a 2022 California Groundwater Ambient Monitoring and Assessment Priority Basin Project (GAMA-PBP) water-quality survey of 33 domestic and small-system drinking-water supply wells in the Gilroy-Hollister Valley groundwater basin and the surrounding areas, where more than 20,000 residents are estimated to utilize privately owned domestic wells. The study area includes the Llagas subbasin in the north, the North San Benito subbasin in the south, and the surrounding uplands. The study was focused on groundwater resources used for domestic drinking-water supply, which are mostly drawn from shallower parts of aquifer systems rather than those of groundwater resources used for public drinking-water supply in the same area. This assessment characterized the quality of ambient groundwater in the aquifer before filtration or treatment, rather than the quality of drinking water delivered to the tap.
To provide context, the measured concentrations of constituents in groundwater were compared to Federal and California State regulatory and non-regulatory benchmarks for drinking-water quality. A grid-based method was used to estimate the areal proportions of groundwater resources used for domestic drinking wells that have water-quality constituents present at high concentrations (above the benchmark), moderate concentrations (between one-half of the benchmark and the benchmark for inorganic constituents, or between one-tenth of the benchmark and the benchmark for organic constituents), and low concentrations (less than one-half or one-tenth the benchmark for inorganic and organic constituents, respectively). This method provides statistically representative results at the study-area scale and permits comparisons to other GAMA-PBP study areas. In the study area, inorganic constituents in groundwater were greater than regulatory benchmarks (U.S. Environmental Protection Agency [EPA] or State of California maximum contaminant levels [MCLs]) for public drinking-water quality in 24 percent of domestic groundwater resources. The inorganic constituents present at concentrations greater than MCLs for drinking water were nitrate (as nitrogen), barium, chromium, and selenium. Total dissolved solids (TDS) or manganese were present at concentrations greater than the secondary maximum contaminant levels (SMCLs) that the State of California uses as aesthetic-based benchmarks in 48 percent of domestic groundwater resources. No volatile organic compounds or pesticide constituents were present at concentrations greater than regulatory benchmarks. Total coliform bacteria and enterococci were detected in 4 percent of domestic groundwater resources. Per- and polyfluoroalkyl substances (PFAS) were detected in 19 percent of domestic groundwater resources, and 10 percent had concentrations greater than recently enacted (April 2024) EPA MCLs.
Physical and chemical factors from natural and anthropogenic sources that could affect the groundwater quality were evaluated using results from statistical testing of associations between constituent concentrations and potential explanatory variables. In this study, relevant physical factors include well construction characteristics, groundwater age, site proximity to groundwater recharge or discharge zones, and potential sources of contamination. Relevant chemical factors include the initial chemistry of the recharge water, the mineralogy of the aquifer sediments, and the subsequent shifts in chemistry as biologic and geologic reactions alter groundwater in the subsurface.
Nitrate concentrations were correlated to agricultural land use, distance from the boundary of the Gilroy-Hollister Valley groundwater basin, and the proportion of modern (post-1950s) water captured by the well. Denitrification under anoxic redox conditions can mitigate some nitrate derived from fertilizer application. Total dissolved solids primarily were derived from water-rock interactions with soils and aquifer materials in the study area, but there were high concentrations where agricultural practices contributed additional TDS. Mineralogy of aquifer sediments and rocks also affect barium, selenium, boron, and chromium concentrations in the Gilroy-Hollister Valley groundwater basin. PFAS were positively correlated with urban land use and the proportion of modern water captured by the well.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20255097","collaboration":"Prepared in cooperation with the California State Water Resources Control Board","usgsCitation":"Faulkner, K.E., and Jurgens, B.C., 2025, Quality of groundwater used for domestic supply in the Gilroy-Hollister basin and surrounding areas, California, 2022: U.S. Geological Survey Scientific Investigations Report 2025–5097, 26 p., https://doi.org/10.3133/sir20255097.","productDescription":"viii, 26 p.","onlineOnly":"Y","ipdsId":"IP-160699","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":496804,"rank":5,"type":{"id":31,"text":"Publication XML"},"url":"https://pubs.usgs.gov/sir/2025/5097/sir20255097.XML"},{"id":496803,"rank":4,"type":{"id":34,"text":"Image Folder"},"url":"https://pubs.usgs.gov/sir/2025/5097/images"},{"id":496801,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2025/5097/sir20255097.pdf","text":"Report","size":"6.2 MB","linkFileType":{"id":1,"text":"pdf"},"description":"SIR 2025-5097"},{"id":496800,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2025/5097/coverthb.jpg"},{"id":496802,"rank":3,"type":{"id":39,"text":"HTML Document"},"url":"https://pubs.usgs.gov/publication/sir20255097/full","text":"Report","linkFileType":{"id":5,"text":"html"},"description":"SIR 2025-5097"},{"id":497802,"rank":6,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_119048.htm"}],"country":"United States","state":"California","otherGeospatial":"Gilroy-Hollister basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -121.61037451371827,\n 37.22507246909019\n ],\n [\n -121.7786749960862,\n 37.08414386069212\n ],\n [\n -121.42503094452843,\n 36.75628159886837\n ],\n [\n -121.29294616762297,\n 36.61961329116167\n ],\n [\n -121.07884238942088,\n 36.64012907347609\n ],\n [\n -121.29720693932853,\n 36.95316849961171\n ],\n [\n -121.61037451371827,\n 37.22507246909019\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","contact":"Director, California Water Science Center
U.S. Geological Survey
6000 J Street, Placer Hall
Sacramento, California 95819
The U.S. Geological Survey works with the California State Water Resources Control Boards’ Groundwater Ambient Monitoring and Assessment Program to study the quality of groundwater used for drinking-water supplies across California. This report examines the quality of groundwater collected from 33 private domestic wells in the Gilroy-Hollister Valley groundwater basin and surrounding area in California’s Central Coast region. Groundwater samples were analyzed for human-made and naturally occurring substances that can be found dissolved in groundwater. They were also analyzed for geochemical tracers that can be used to help determined the age of the groundwater and processes affecting the concentrations of dissolved constituents. The water-quality data were compared to Federal and State benchmarks that are applied to public drinking water, such as regulatory maximum contaminant levels (MCLs). Nitrate was detected at concentrations greater than its Federal MCL benchmark in 17 percent of the groundwater samples. Nitrate concentrations above natural background levels were associated with greater agricultural land use near the well, wells tapping a higher proportion of younger groundwater, and absence of anoxic conditions that promote degradation of nitrate. No volatile organic compounds or pesticide constituents were detected at concentrations greater than MCLs, however per- and polyfluoroalkyl substances (PFAS) were detected at concentrations greater than the Federal MCLs enacted in April 2024 in about 10 percent of the groundwater samples. PFAS are used in many consumer products and industrial processes. Occurrences of these elevated concentrations of PFAS were not associated with known potential sources of PFAS contamination to groundwater but were positively correlated with urban land use and the proportion of younger groundwater tapped by the well. Total dissolved solids (TDS, a measure of salinity) were detected at concentrations about the State nonregulatory upper secondary MCL in 24 percent of the groundwater samples. TDS is primarily derived from natural interactions between water and aquifer materials although agricultural practices may contribute additional TDS is some areas. About 20,000 residents in the Gilroy-Hollister area, and more than 2 million people in California, use private domestic wells for drinking water. Therefore, assessing the quality of groundwater used by domestic wells and understanding the factors affecting that quality is important for protecting public health.
","publicationDate":"2025-12-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Faulkner, Kirsten E. 0000-0003-1628-2877","orcid":"https://orcid.org/0000-0003-1628-2877","contributorId":362930,"corporation":false,"usgs":false,"family":"Faulkner","given":"Kirsten","middleInitial":"E.","affiliations":[{"id":68550,"text":"California Water Science Center","active":true,"usgs":false}],"preferred":false,"id":950836,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jurgens, Bryant C. 0000-0002-1572-113X bjurgens@usgs.gov","orcid":"https://orcid.org/0000-0002-1572-113X","contributorId":127839,"corporation":false,"usgs":true,"family":"Jurgens","given":"Bryant C.","email":"bjurgens@usgs.gov","affiliations":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"preferred":false,"id":950837,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70271966,"text":"ofr20251037 - 2025 - Reconnaissance of potential alternate water supply sources for the City of Gary, West Virginia","interactions":[],"lastModifiedDate":"2026-02-03T16:28:45.074551","indexId":"ofr20251037","displayToPublicDate":"2025-11-14T14:55:00","publicationYear":"2025","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"2025-1037","displayTitle":"Reconnaissance of Potential Alternate Water Supply Sources for the City of Gary, West Virginia","title":"Reconnaissance of potential alternate water supply sources for the City of Gary, West Virginia","docAbstract":"Seven potential sources of water, consisting of free-flowing discharge from abandoned coal mines at six locations and one abandoned flooded underground coal mine air shaft, were sampled for chemical analysis to assess the quality of the groundwater emanating from the seven mine sources. The six free-flowing mine discharge sources were also assessed for discharge by current-meter measurements on two separate occasions. The U.S. Geological Survey assessed these seven sources to provide information to the City of Gary, West Virginia (W. Va.), and the City of Gary’s consulting engineer with groundwater-quality and flow data to allow them to assess the seven sites as potential alternate sources of water for the City of Gary to augment its existing supply.
For the six sites where discharge could be measured, discharge ranged from a minimum of 0.082 cubic feet per second (ft3/s) to a maximum of 3.685 ft3/s. Of the six sites measured, only two, Harmon Branch at Thorpe, W. Va. (USGS site 372201081303501) and the abandoned public-supply water wells near Havaco, W. Va. (USGS site 372358081344601), had discharge in excess of 1.00 ft3/s. Discharge from the abandoned public supply wells was 3.685 ft3/s on September 20, 2023, and 2.888 ft3/s on October 16, 2023, and discharge from Harmon Branch at Thorpe, W. Va., was 1.049 ft3/s on September 22, 2023, and 1.038 ft3/s on October 17, 2023. Discharge in the abandoned underground mine air shaft (USGS site 372224081340901) could not be assessed, but the air shaft drains an abandoned mine that likely contains water stored in approximately 1.7 square miles (mi2) of abandoned underground coal mines in the Pocahontas No. 3 coal seam, and possibly an additional 0.9 mi2 of leakage from the overlying Pocahontas No. 4 coal seam. Discharge for the six sites measured for the study was measured during a period between September 20 and October 18, 2023, and corresponded to the 12th to the 15th percentile of flow-duration statistics for the Tug Fork downstream of Elkhorn Creek at Welch, W. Va. streamgage (USGS site 03212750).
Water-quality data for the seven sites sampled overall were acceptable with respect to drinking water standards. Of the 203 constituents analyzed, only a few failed to meet applicable U.S. Environmental Protection Agency (EPA) drinking water standards. Iron exceeded the 300 micrograms per liter (μg/L) secondary maximum contaminant level (SMCL) at only 1 of the 7 sites (14.3 percent) sampled. Iron concentrations ranged from a minimum of less than (<) 5.00 μg/L to a maximum of 724 μg/L with a median concentration of 7.62 μg/L. Manganese exceeded the 50.0 μg/L SMCL at 2 of the 7 sites (28.6 percent) sampled. Manganese concentrations ranged from a minimum of 1.93 μg/L to a maximum of 271 μg/L with a median concentration of 4.03 μg/L. No sites sampled exceeded the arsenic maximum contaminant level (MCL) of 10 μg/L. Arsenic concentrations ranged from a minimum of <0.100 μg/L to a maximum of 2.35 μg/L with a median arsenic concentration of 0.200 μg/L. None of the seven sites sampled for selenium for this study exceeded the EPA MCL of 50.0 μg/L. Selenium concentrations ranged from a minimum of <0.050 μg/L to a maximum of 5.26 μg/L with a median concentration of 3.21 μg/L.
All seven sites were sampled for volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), and polychlorinated biphenyls (PCBs), but most had concentrations below the detection limit. Of the 10 PCB compounds analyzed for the seven sites sampled, none contained detectable concentrations of PCBs or Aroclor compounds. Of the 44 SVOCs analyzed at each of the seven sites sampled, only 1 SVOC, acenaphthene, was detected, at a concentration of 0.02 μg/L. Of the 96 VOCs analyzed, from each of the seven sites sampled, only two were found at detectable concentrations. Trichloromethane was detected only at 1 of the 7 (14.3 percent) sites sampled at a concentration of 0.027 μg/L, and benzene was detected at the same site and 3 additional sites (4 of the 7 sites or 57.1 percent of the sites sampled) at concentrations of 0.028, 0.029, 0.021, and 0.035 μg/L, but none exceeded the EPA MCL for benzene of 5.00 μg/L.
Total coliform bacteria are ubiquitous in the environment, and their presence only suggests the potential for contamination by near-surface processes. Escherichia coli (E. coli) bacteria are derived from either human or animal fecal material and can be an indicator of potential contamination by pathogenic bacteria or viruses. Total coliform bacteria were detected at all 7 sites sampled at concentrations ranging from 17.5 to greater than (>) 2,420 most probable number per 100 mL (MPN/100 mL) of sample, with a median total coliform concentration of 1,553 MPN/100 mL. Escherichia coli bacteria were detected at 4 of the 7 sites sampled at concentrations ranging from <1 to 11.9 MPN/100 mL, with a median E. coli concentration of 5.1 MPN/100 mL.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/ofr20251037","collaboration":"Prepared in cooperation with the City of Gary, West Virginia","usgsCitation":"Kozar, M.D., and Austin, S.H., 2025, Reconnaissance of potential alternate water supply sources for the City of Gary, West Virginia: U.S. Geological Survey Open-File Report 2025–1037, 27 p., https://doi.org/10.3133/ofr20251037.","productDescription":"Report: viii, 27 p.; Appendix","numberOfPages":"27","onlineOnly":"Y","additionalOnlineFiles":"Y","ipdsId":"IP-176784","costCenters":[{"id":37280,"text":"Virginia and West Virginia Water Science Center ","active":true,"usgs":true}],"links":[{"id":496467,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/2025/1037/ofr20251037.pdf","text":"Report","size":"5.71 MB","linkFileType":{"id":1,"text":"pdf"},"description":"OFR 2025-1037 PDF"},{"id":496466,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/of/2025/1037/coverthb.jpg"},{"id":497789,"rank":7,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_118952.htm"},{"id":496471,"rank":6,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/of/2025/1037/ofr20251037_app2.csv","text":"Appendix 2","size":"222 KB","linkFileType":{"id":7,"text":"csv"},"linkHelpText":"- Water-Quality Data Collected During the Study"},{"id":496470,"rank":5,"type":{"id":31,"text":"Publication XML"},"url":"https://pubs.usgs.gov/of/2025/1037/ofr20251037.XML","linkFileType":{"id":8,"text":"xml"},"description":"OFR 2025-1037 XML"},{"id":496469,"rank":4,"type":{"id":34,"text":"Image Folder"},"url":"https://pubs.usgs.gov/of/2025/1037/images/"},{"id":496468,"rank":3,"type":{"id":39,"text":"HTML Document"},"url":"https://pubs.usgs.gov/publication/ofr20251037/full","text":"Report","linkFileType":{"id":5,"text":"html"},"description":"OFR 2025-1037 HTML"}],"country":"United States","state":"West Virginia","city":"Gary","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -81.616667,\n 37.433333\n ],\n [\n -81.616667,\n 37.25\n ],\n [\n -81.45,\n 37.25\n ],\n [\n -81.45,\n 37.433333\n ],\n [\n -81.616667,\n 37.433333\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","contact":"Director, Virginia and West Virginia Water Science Center
U.S. Geological Survey
1730 East Parham Road
Richmond, Virginia 23228
The drivers of population dynamics are a primary interest of ecologists, and predicting the consequences of climate variability on wildlife populations benefits from an understanding of how weather causes variation in the vital rates of populations. Given recent and projected extremes in annual precipitation in the Sierra Nevada of California, USA, including two severe droughts, we sought to examine the role of snowpack and summer water availability on the population dynamics and potential extirpation of a meadow population of the U.S. Endangered Sierra Nevada yellow-legged frog (Rana sierrae) using a long-term capture-mark-recapture dataset. We found that snowpack and summer water availability affected both survival and recruitment probabilities. Although these variables only explained approximately 17 % of the annual variation in adult survival, they explained 81 % of the variation in recruitment into the adult population. Following two severe, extended droughts and a nearby wildfire, the population consisted of 20 or fewer individuals with >95 % certainty, and 10 or fewer individuals with 64 % certainty. If realized, increased precipitation volatility and extended droughts likely present an additional threat to some meadow populations of this endangered frog.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.ecochg.2025.100099","usgsCitation":"Halstead, B., Kleeman, P.M., Rose, J.P., Grasso, R.L., and Fellers, G.M., 2025, Climatological effects on survival, recruitment, and possible extirpation of a Sierra Nevada anuran: Climate Change Ecology, v. 10, 100099, 11 p., https://doi.org/10.1016/j.ecochg.2025.100099.","productDescription":"100099, 11 p.","ipdsId":"IP-161742","costCenters":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true}],"links":[{"id":497114,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1016/j.ecochg.2025.100099","text":"Publisher Index Page"},{"id":497060,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Summit Meadow, Yosemite National Park","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -119.64672349244009,\n 37.675274534515\n ],\n [\n -119.65704609741877,\n 37.675274534515\n ],\n [\n -119.65704609741877,\n 37.668624663917555\n ],\n [\n -119.64672349244009,\n 37.668624663917555\n ],\n [\n -119.64672349244009,\n 37.675274534515\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"10","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Halstead, Brian J. 0000-0002-5535-6528 bhalstead@usgs.gov","orcid":"https://orcid.org/0000-0002-5535-6528","contributorId":215986,"corporation":false,"usgs":true,"family":"Halstead","given":"Brian","email":"bhalstead@usgs.gov","middleInitial":"J.","affiliations":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true}],"preferred":true,"id":951347,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kleeman, Patrick M. 0000-0001-6567-3239 pkleeman@usgs.gov","orcid":"https://orcid.org/0000-0001-6567-3239","contributorId":3948,"corporation":false,"usgs":true,"family":"Kleeman","given":"Patrick","email":"pkleeman@usgs.gov","middleInitial":"M.","affiliations":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true}],"preferred":true,"id":951348,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rose, Jonathan P. 0000-0003-0874-9166 jprose@usgs.gov","orcid":"https://orcid.org/0000-0003-0874-9166","contributorId":199339,"corporation":false,"usgs":true,"family":"Rose","given":"Jonathan","email":"jprose@usgs.gov","middleInitial":"P.","affiliations":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true}],"preferred":true,"id":951349,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Grasso, Robert L.","contributorId":363246,"corporation":false,"usgs":false,"family":"Grasso","given":"Robert","middleInitial":"L.","affiliations":[{"id":36245,"text":"NPS","active":true,"usgs":false}],"preferred":false,"id":951350,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Fellers, Gary M.","contributorId":209920,"corporation":false,"usgs":false,"family":"Fellers","given":"Gary","email":"","middleInitial":"M.","affiliations":[{"id":38025,"text":"9 Goldfinch Court, Novato, CA 94947; gary_fellers@worldnet.att.net","active":true,"usgs":false}],"preferred":false,"id":951351,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70273772,"text":"70273772 - 2025 - VIPER site analysis","interactions":[],"lastModifiedDate":"2026-01-28T15:34:44.161644","indexId":"70273772","displayToPublicDate":"2025-10-14T08:12:17","publicationYear":"2025","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":8607,"text":"The Planetary Science Journal","active":true,"publicationSubtype":{"id":10}},"title":"VIPER site analysis","docAbstract":"We needed to evaluate available orbital data of NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) mission area in order to derive a variety of maps to help the science team identify scientifically interesting places for the rover to visit and to provide scientific context for our mission. Some of these maps also fulfilled engineering and mission design needs to enable safe and efficient landing and roving. We incorporated data from the Lunar Reconnaissance Orbiter Camera, the Lunar Orbital Laser Altimeter, the Mini-RF instrument, the Chandrayaan-2 Orbital High Resolution Camera, the Korean Pathfinder Lunar Orbiter’s Shadowcam, the Kaguya Spectral Profiler and Multiband Imager, and the Chandrayaan-1 Moon Mineralogy Mapper. We used a variety of techniques to build these maps, including stereogrammetry, shape-from-shading, ice stability depth and surface temperature calculations, and the horizon method for solar illumination and direct-to-Earth communications maps. Altogether, these maps allowed us to survey for boulders, evaluate features in permanently shadowed regions that VIPER might explore, provide mineralogic context for what VIPER’s instruments may learn, estimate the ages and radar properties of craters in the VIPER mission area, and evaluate the potential for gravity traverses with the rover. These data and techniques provided a rich set of information from which both the VIPER science team and engineering teams were able to draw in order to plan a safe landing and to plan a VIPER surface mission that will be both scientifically valuable and robust from an operational perspective.
","language":"English","publisher":"American Astronomical Society","doi":"10.3847/PSJ/ae061a","usgsCitation":"Beyer, R.A., Shirley, M., Colaprete, A., Fassett, C.I., Fernando, B., Himani, T.P., Lemelin, M., Martinez-Comacho, J., Siegler, M., Annex, A., Balaban, E., Bickel, V.T., Coyan, J.A., Deutsch, A.N., Heldmann, J.L., Hirabayashi, M., Keszthelyi, L.P., Lewis, K.W., Lim, D.S., and Dobrea, E., 2025, VIPER site analysis: The Planetary Science Journal, v. 6, 236, 18 p., https://doi.org/10.3847/PSJ/ae061a.","productDescription":"236, 18 p.","ipdsId":"IP-180642","costCenters":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"links":[{"id":499324,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.3847/psj/ae061a","text":"Publisher Index 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Here we present chemical and isotopic analyses of gas samples collected between 2015 and 2023, along with the first comprehensive CO2 flux survey of the SBMM area conducted in 2023. Sampled gases are CO2- and CH4-rich (≥84 and 6 mol% in dry gas, respectively) with high mantle-derived helium contributions (3He/4He = 6.54–7.86 RC/RA). Carbon isotopic compositions of CO2 (δ13C = −10.0 to −9.5 ‰) and CH4 (δ13C = −35.8 ‰) indicate mixed sources, with significant contributions from metamorphism of organic-rich Franciscan Complex rocks hosting the hydrothermal system. Modeling of gas compositions shows that scrubbing by interaction with air-saturated groundwater strongly influences observed compositional variability. From our CO₂ flux measurements, we estimate the deeply derived CO2 emission rate from the SBMM hydrothermal area (0.2 km2) at 240 t d−1, comparable to many quiescently degassing volcanoes worldwide. We also provide a first-order estimate of CH4 emissions at approximately 0.5 t d−1. Our findings establish crucial baseline data for future volcanic monitoring efforts, enhancing detection capabilities for potential changes in this active hydrothermal system. This work contributes to the broader understanding of volatile contributions from volcanic and metamorphic sources to the global carbon budget, while highlighting the strong influence of bedrock geology on gas compositions in the CLVF.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.jvolgeores.2025.108453","usgsCitation":"Lewicki, J.L., Peek, S., Clor, L., and Hunt, A.G., 2025, Gas emissions from the Sulphur Bank Mercury Mine hydrothermal system, Clear Lake volcanic field, California: Journal of Volcanology and Geothermal Research, v. 468, 108453, 11 p., https://doi.org/10.1016/j.jvolgeores.2025.108453.","productDescription":"108453, 11 p.","ipdsId":"IP-177603","costCenters":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"links":[{"id":496226,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Clear Lake Volcanic Field","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -122.93378541824276,\n 39.13626270834021\n ],\n [\n -122.93378541824276,\n 38.65\n ],\n [\n -122.25,\n 38.65\n ],\n [\n -122.25,\n 39.13626270834021\n ],\n [\n -122.93378541824276,\n 39.13626270834021\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"468","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Lewicki, Jennifer L. 0000-0003-1994-9104 jlewicki@usgs.gov","orcid":"https://orcid.org/0000-0003-1994-9104","contributorId":5071,"corporation":false,"usgs":true,"family":"Lewicki","given":"Jennifer","email":"jlewicki@usgs.gov","middleInitial":"L.","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true},{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":949539,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Peek, Sara 0000-0002-9770-6557","orcid":"https://orcid.org/0000-0002-9770-6557","contributorId":209971,"corporation":false,"usgs":true,"family":"Peek","given":"Sara","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":true,"id":949540,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Clor, Laura E. 0000-0003-2633-5100","orcid":"https://orcid.org/0000-0003-2633-5100","contributorId":209969,"corporation":false,"usgs":true,"family":"Clor","given":"Laura E.","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":true,"id":949541,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hunt, Andrew G. 0000-0002-3810-8610 ahunt@usgs.gov","orcid":"https://orcid.org/0000-0002-3810-8610","contributorId":174135,"corporation":false,"usgs":true,"family":"Hunt","given":"Andrew","email":"ahunt@usgs.gov","middleInitial":"G.","affiliations":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true}],"preferred":true,"id":949542,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70271698,"text":"70271698 - 2025 - Ultraviolet and visible remote sensing of volcanic gases","interactions":[],"lastModifiedDate":"2025-09-19T14:52:18.799677","indexId":"70271698","displayToPublicDate":"2025-09-10T09:49:54","publicationYear":"2025","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Ultraviolet and visible remote sensing of volcanic gases","docAbstract":"Freshwater mussels are among the most sensitive species to a variety of chemicals in water exposures. However, few studies have been conducted to evaluate the effect of toxicants in sediments on mussels. Industrial discharges containing polyaromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and metals entered the Kanawha River surrounding Blaine Island, South Charleston, West Virginia, USA; a river which supports eight federally endangered mussel species. We collected sediment samples from a highly contaminated site, a nearby upstream site, and a further upstream reference site to assess the effects of contaminated sediment on the survival and growth of a unionid mussel (fatmucket, Lampsilis siliquoidea) and a commonly tested benthic organism (amphipod, Hyalella azteca) using standard 28-d sediment toxicity tests. We also determined mussel toxicity in a serial dilution of the highly contaminated sediment. Results showed that concentrations of PAHs, VOCs, and metals in the contaminated sediment were consistently greater than the other two sites. The mean survival of mussels and amphipods in the reference sediment was 100% and 95%, respectively, whereas the mean survival of both test species in the contaminated sediment was 0%. In the sediment dilution study, mean survival and biomass of mussels in the ≥6.25% treatment were significantly reduced relative to the control, with a 25% inhibition concentration of 4.1% for survival and 3.6% for biomass. We used sediment screening values and equilibrium partitioning sediment benchmarks to determine that nickel, mercury, and PAH mixture were likely responsible for the toxicity observed to mussels and amphipods and will provide critical data to identify and mitigate the sources of the mixture in contaminated sediment.
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The degree to which streamflow affects nearshore productivity varies as a function of catchment characteristics, internal lake morphometry, and processes. This study investigates the relative influence of streamflow on nearshore metabolism (e.g., gross primary productivity [GPP], ecosystem respiration [ER], and net ecosystem productivity [NEP]) for shores with large, small, or no stream inflows (four locations across two shores) during two contrasting water years (one drought and one wet) in Lake Tahoe (Nevada/California, USA). Using Bayesian structural equation modeling, we found streamflow decreased water temperature, benthic light, and GPP across both years. Compared to the drought year, the subsequent wet year had 54% higher annual streamflow, 37% less light, and lower NEP at locations with large or small inflows (39% Δ −0.32 mmol O₂ m−3 d−1% and 49% Δ −1.19 mmol O₂ m−3 d−1, respectively). During the wet year, we observed a 68% increase in the negative association between streamflow and nearshore GPP at the large inflow and a 62% decrease in the positive association between streamflow and GPP at the small inflow. This work demonstrates how oligotrophic littoral productivity varies across shorelines and in response to hydrological conditions, with streamflow and precipitation exerting contrasting effects depending on the proximity to inflowing streams. Our results suggest future lake responses to climate volatility depend on spatial and temporal hydrologic connectivity to catchments and upland processes.
","language":"English","publisher":"Association for the Sciences of Limnology and Oceanography","doi":"10.1002/lno.70157","usgsCitation":"Loria, K., Lowman, H., Krause, J., Katona, L.R., Naranjo, R.C., Scordo, F., Harpold, A., Chandra, S., and Blaszczak, J., 2025, The influence of mountain streamflow on nearshore ecosystem metabolism in a large, oligotrophic lake across a drought and a wet year: Limnology and Oceanography, v. 70, no. 9, p. 2645-2659, https://doi.org/10.1002/lno.70157.","productDescription":"15 p.","startPage":"2645","endPage":"2659","ipdsId":"IP-171346","costCenters":[{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true}],"links":[{"id":493851,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California, Nevada","otherGeospatial":"Lake Tahoe","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -120.22907288918867,\n 39.27733095987708\n ],\n [\n -120.22907288918867,\n 38.90788242474909\n ],\n [\n -119.85664507888565,\n 38.90788242474909\n ],\n [\n -119.85664507888565,\n 39.27733095987708\n ],\n [\n -120.22907288918867,\n 39.27733095987708\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"70","issue":"9","noUsgsAuthors":false,"publicationDate":"2025-08-06","publicationStatus":"PW","contributors":{"authors":[{"text":"Loria, Kelly 0000-0002-0067-0413","orcid":"https://orcid.org/0000-0002-0067-0413","contributorId":359371,"corporation":false,"usgs":false,"family":"Loria","given":"Kelly","affiliations":[{"id":38163,"text":"UNR","active":true,"usgs":false}],"preferred":false,"id":945205,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lowman, Heili 0000-0002-2939-9225","orcid":"https://orcid.org/0000-0002-2939-9225","contributorId":359373,"corporation":false,"usgs":false,"family":"Lowman","given":"Heili","affiliations":[{"id":12643,"text":"Duke University","active":true,"usgs":false}],"preferred":false,"id":945206,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Krause, Jasimine 0009-0002-2017-0229","orcid":"https://orcid.org/0009-0002-2017-0229","contributorId":359376,"corporation":false,"usgs":false,"family":"Krause","given":"Jasimine","affiliations":[{"id":38163,"text":"UNR","active":true,"usgs":false}],"preferred":false,"id":945207,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Katona, Leon R. 0000-0001-5323-1871","orcid":"https://orcid.org/0000-0001-5323-1871","contributorId":331458,"corporation":false,"usgs":true,"family":"Katona","given":"Leon","email":"","middleInitial":"R.","affiliations":[{"id":37947,"text":"Upper Midwest Water Science Center","active":true,"usgs":true}],"preferred":true,"id":945208,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Naranjo, Ramon C. 0000-0003-4469-6831 rnaranjo@usgs.gov","orcid":"https://orcid.org/0000-0003-4469-6831","contributorId":3391,"corporation":false,"usgs":true,"family":"Naranjo","given":"Ramon","email":"rnaranjo@usgs.gov","middleInitial":"C.","affiliations":[{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true}],"preferred":true,"id":945209,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Scordo, Facundo 0000-0001-6182-7368","orcid":"https://orcid.org/0000-0001-6182-7368","contributorId":359380,"corporation":false,"usgs":false,"family":"Scordo","given":"Facundo","affiliations":[{"id":85780,"text":"Universidad Nacional del Sur, Argentina","active":true,"usgs":false}],"preferred":false,"id":945210,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Harpold, Adrian A. 0000-0002-2566-9574","orcid":"https://orcid.org/0000-0002-2566-9574","contributorId":353577,"corporation":false,"usgs":false,"family":"Harpold","given":"Adrian A.","affiliations":[{"id":84439,"text":"Dept. of Natural Resources and Environmental Science, Univ. of Nevada, Reno, Reno, NV","active":true,"usgs":false}],"preferred":false,"id":945211,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Chandra, Sudeep 0000-0003-1724-5154","orcid":"https://orcid.org/0000-0003-1724-5154","contributorId":359381,"corporation":false,"usgs":false,"family":"Chandra","given":"Sudeep","affiliations":[{"id":38163,"text":"UNR","active":true,"usgs":false}],"preferred":false,"id":945212,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Blaszczak, Joanna 0000-0001-5122-0829","orcid":"https://orcid.org/0000-0001-5122-0829","contributorId":225159,"corporation":false,"usgs":false,"family":"Blaszczak","given":"Joanna","email":"","affiliations":[{"id":41055,"text":"Natural Resources and Environmental Science, University of Nevada, Reno, NV 89557, USA","active":true,"usgs":false}],"preferred":false,"id":945213,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}} ,{"id":70269821,"text":"gip256 - 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It is a “network of networks” with 81 subnetworks being sampled on a decadal time scale. Each year, 8 of the subnetworks are sampled. Subnetworks have 20–30 wells each and include studies of domestic supply wells or shallow groundwater (20–50 feet deep) underlying urban land use or agricultural land use. Currently there are 2,089 wells in the network. All wells are sampled for physical properties, nutrients, major ions, trace elements, per- and polyfluoroalkyl substances (PFAS), and a subset of wells are sampled for pesticides, volatile organic compounds, radionuclides, and microbiological contaminants.
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Observing Systems Division
Water Mission Area
U.S. Geological Survey
12201 Sunrise Valley Drive
Reston, VA 20192
The U.S. Geological Survey (USGS)—in cooperation with the U.S. Department of Energy (DOE) for the Naval Reactors Laboratory Field Office that supports operations for the Naval Reactors Facility (NRF) located at the Idaho National Laboratory (INL)—drilled and constructed well NRF-17 (formerly borehole USGS 151) and well NRF-18 (formerly borehole USGS 152) for stratigraphic framework analyses and water-quality monitoring at the Idaho National Laboratory (INL) near the NRF, in southeastern Idaho. Borehole USGS 151 was continuously cored from about 48 to 1,070 feet (ft) below land surface (BLS); rotary drilled from approximately 1,070 to 1,720 ft BLS; and re-drilled to complete construction as a monitor well NRF-17, completed to 461 ft BLS. Borehole USGS 152 was continuously cored from approximately 19 to 1,259 ft BLS; rotary drilled from approximately 1,259 to 1,630 ft BLS; and re-drilled to complete construction as a monitor well NRF-18, completed to 450 ft BLS.
Geophysical data were examined with photographed core material to record lithologic descriptions and to suggest zones where groundwater flow was anticipated. Basalt flows varied from highly fractured to dense, with high-to-low vesiculation. Well NRF-17 generally was constructed in mostly dense basalt (greater than 75 percent), and well NRF-18 was constructed in primarily fractured and (or) vesicular basalt. In well NRF-17, the well capacity is directly affected by the limited amount of fractured basalt, which serves as the primary pathway for groundwater. This effect was observed during the pumping test conducted after the well's final construction.
Single-well aquifer tests were done at wells NRF-17 and NRF-18 to provide estimates of transmissivity and hydraulic conductivity after final well construction and initial well development. Estimated values of transmissivity and hydraulic conductivity for well NRF-17 were 8.81 feet squared per day (ft2/d) and 1.04×10-2 feet per day (ft/d), respectively. Estimated values of transmissivity and hydraulic conductivity for well NRF-18 were 4.77×103 ft2/d and 5.61 ft/d, respectively. The NRF-17 pump test resulted in 19.41 ft of measured drawdown at a sustained average pumping rate of 3.3 gallons per minute (gal/min). The NRF-18 pump test resulted in 0.55 ft of measured drawdown at a sustained average pumping rate of 31.0 gal/min.
Water-quality samples collected from the two wells were analyzed for cations, anions, metals, nutrients, volatile organic compounds, stable isotopes, and radionuclides. Water samples for select inorganic constituents showed concentrations consistent with signatures from tributary valley groundwater with influences from ephemeral surface-water recharge from the Big Lost River. Water-quality samples analyzed for stable isotopes of oxygen and hydrogen are consistent with signatures from tributary valley groundwater and surface-water recharge inputs to the aquifer. No measured water-quality results were greater than their respective maximum contaminant levels for public drinking-water supplies. Inorganic and nutrient water-quality results for well NRF-17 and well NRF-18 suggest the groundwater in this area is potentially affected by industrial wastewater disposal.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20255049","collaboration":"Prepared in cooperation with the U.S. Department of Energy","programNote":"DOE/ID-22264","usgsCitation":"Twining, B.V., Treinen, K.C., and Zingre, J.A., 2025, Completion summary for monitor wells NRF-17 and NRF-18 at the Naval Reactors Facility, Idaho National Laboratory, Idaho: U.S. Geological Survey Scientific Investigations Report\n2025–5049, 37 p., https://doi.org/10.3133/sir20255049.","productDescription":"Report: vii, 37 p.; Data Release","onlineOnly":"Y","ipdsId":"IP-159224","costCenters":[{"id":343,"text":"Idaho Water Science Center","active":true,"usgs":true}],"links":[{"id":491691,"rank":5,"type":{"id":34,"text":"Image Folder"},"url":"https://pubs.usgs.gov/sir/2025/5049/images"},{"id":499046,"rank":7,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_118682.htm","linkFileType":{"id":5,"text":"html"}},{"id":491692,"rank":6,"type":{"id":31,"text":"Publication XML"},"url":"https://pubs.usgs.gov/sir/2025/5049/sir20255049.XML"},{"id":491689,"rank":3,"type":{"id":39,"text":"HTML Document"},"url":"https://pubs.usgs.gov/publication/sir20255049/full","linkFileType":{"id":5,"text":"html"},"description":"SIR 2025-5049"},{"id":491687,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2025/5049/coverthb.jpg"},{"id":491688,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2025/5049/sir20255049.pdf","size":"3.8 MB","linkFileType":{"id":1,"text":"pdf"},"description":"SIR 2025-5049"},{"id":491690,"rank":4,"type":{"id":30,"text":"Data Release"},"url":"https://doi.org/10.5066/P13URUXF","text":"USGS data release","description":"USGS data release","linkHelpText":"Single-well aquifer test data from wells NRF-17 and NRF-18, Idaho National Laboratory, Idaho"}],"country":"United States","state":"Idaho","otherGeospatial":"Idaho National Laboratory, Naval Reactors Facility","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -112.5,\n 44\n ],\n [\n -113.5,\n 44\n ],\n [\n -113.5,\n 43.25\n ],\n [\n -112.5,\n 43.25\n ],\n [\n -112.5,\n 44\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","contact":"Director, Idaho Water Science Center
U.S. Geological Survey
230 Collins Rd
Boise, Idaho 83702-4520
The Wilcox Oil Company Superfund site (hereinafter referred to as “the site”) was formerly an oil refinery northeast of Bristow in Creek County, Oklahoma. Historical refinery operations contaminated the soil, surface water, streambed sediments, alluvium, and groundwater with refined and stored products at the site. The Wilcox and Lorraine process areas are where the highest concentrations of volatile organic compounds, semivolatile organic compounds, polycyclic aromatic hydrocarbons, and trace elements (including metals) (collectively hereinafter referred to as “contaminants”) were measured in a local shallow perched groundwater system within the alluvium (hereinafter referred to as the “alluvial aquifer”) at the site during previous site assessments. In order to understand the potential migration of contaminants through the soil and groundwater in these areas, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, investigated aquifer characteristics of the alluvial aquifer in the Wilcox and Lorraine process areas of the site to (1) document hydraulic conductivity and other aquifer characteristics of the alluvial aquifer that govern contaminant fate and transport, (2) describe the geospatial extent and concentration of the contaminants in the alluvial aquifer in the Wilcox and Lorraine process areas, and (3) describe the geochemical controls pertaining to oxidation and reduction governing the fate and transport and the degradation potential of contaminants in the groundwater. Various data were compiled and collected to evaluate the aquifer characteristics at the site including the hydrogeologic framework, groundwater-flow system, geochemistry, and hydraulic properties of the aquifer. A total of 20 new (2022) groundwater monitoring wells were installed at the site to collect data used to supplement groundwater-level altitude and groundwater-quality data collected from older, existing groundwater monitoring wells and piezometers. Data compiled and collected for the study were used to evaluate the characteristics of the alluvial aquifer at the site. These aquifer characteristics are defined by the hydrogeologic framework, groundwater-flow system, geochemistry, and hydraulic properties of the aquifer.
Director, Oklahoma-Texas Water Science Center
U.S. Geological Survey
1505 Ferguson Lane
Austin, TX 78754–4501
Contact Us- USGS Publications Warehouse
","tableOfContents":"We present geochemical data from gas samples from ∼1200 km of arc in the Central Volcanic Zone of the Andes (CVZA), the volcanic arc with the thickest (∼70 km) continental crust globally. The primary goals of this study are to characterize and understand how magmatic gases interact with hydrothermal systems, assess the origins of the major gas species, and constrain gas emission rates. To this end, we use gas chemistry, isotope compositions of H, O, He, C, and S, and SO2 fluxes from the CVZA. Gas and isotope ratios (CO2/ST, CO2/CH4, H2O/ST, δ13C, δ34S, 3He/4He) vary dramatically as magmatic gases are progressively affected by hydrothermal processes, reflecting removal and crustal sequestration of reactive species (e.g., S) and addition of less reactive meteoric and crustal components (e.g., He). The observed variations are similar in magnitude to those expected during the magmatic reactivation of volcanoes with hydrothermal systems. Carbon and sulfur isotope compositions of the highest temperature emissions (97–408 °C) are typical of arc magmatic gases. Helium isotope compositions reach values similar to upper mantle in some volcanic gases indicating that transcustal magma systems are effective conduits for volatiles, even through very thick continental crust. However, He isotopes are highly sensitive to even low degrees of hydrothermal interaction and radiogenic overprinting. Previous work has significantly underestimated volatile fluxes from the CVZA; however, emission rates from this study also appear to be lower than typical arcs, which may be related to crustal thickness.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.jvolgeores.2025.108382","usgsCitation":"de Moor, J., Barry, P., Rodriguez, A., Aguilera, F., Aguilera, M., Gonzalez, C., Layana, S., Chiodi, A., Apaza, F., Masias, P., Kern, C., Barnes, J., Cullen, J.T., Bastoni, D., Bastianoni, A., Cascone, M., Jimenez, C., Salas-Navarro, J., Ramirez, C., Jessen, G., Giovannelli, D., and Lloyd, K., 2025, Origins and fluxes of gas emissions from the Central Volcanic Zone of the Andes: Journal of Volcanology and Geothermal Research, v. 466, 108382, 18 p., https://doi.org/10.1016/j.jvolgeores.2025.108382.","productDescription":"108382, 18 p.","ipdsId":"IP-170019","costCenters":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"links":[{"id":490986,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1016/j.jvolgeores.2025.108382","text":"Publisher Index Page"},{"id":490831,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"Argentina, Bolivia, Chile, Peru","otherGeospatial":"Central Volcanic Zone of the Andes","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -74,\n -14\n ],\n [\n -74,\n -28\n ],\n [\n -64,\n -28\n ],\n [\n -64,\n -14\n ],\n [\n -74,\n -14\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"466","noUsgsAuthors":false,"publicationDate":"2025-06-13","publicationStatus":"PW","contributors":{"authors":[{"text":"de Moor, J. 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parental magmas. This discrepancy has defied simple explanation because the partitioning behavior of both elements between sulfide and silicate liquids is very similar. Assimilation of sulfur- and carbon-rich country rocks by mafic and ultramafic magmas is considered a critical, if not essential, step in the formation of magmatic base metal sulfide deposits. Although there is general consensus that the assimilation of external sulfur and carbon promotes sulfide saturation, the effect of carbon assimilation on the solubilities of platinum-group elements in natural S-bearing silicate melt has been overlooked. In this study, we investigate the variations of platinum and palladium solubilities during assimilation of graphite and methane through thermodynamic modeling, in comparison with data from an array of highly distinctive magmatic sulfide ore systems representing ages from Archean to Paleozoic, melt compositions from komatiite to basalt, and magmatic settings including lavas, hypabyssal intrusions, plutonic continental arc roots, and plutonic layered intrusions, namely: Raglan, Norilsk-Talnakh, Lac des Iles, and the J-M Reef of the Stillwater Complex. We model assimilation-fractional crystallization processes to estimate the reduction of oxygen fugacity (fO2) of the melt due to incorporation of graphite and methane. The simulations show that although Pd remains highly soluble during the progressive assimilation of reduced carbon, Pt solubility decreases significantly as the silicate melt becomes increasingly reduced. With less than 8% of sediment assimilation, Pt alloy may saturate and then deviate from sulfide-undersaturated silicate melts, concomitantly increasing the Pd/Pt value of the remaining melts of the Raglan and Norilsk-Talnakh systems. For the Lac des Iles and Stillwater systems, a higher extent of assimilation is needed to reach Pt saturation because of the relatively carbon-poor nature of the lower crustal rocks. The assimilation of methane volatiles is shown to be more effective than graphite assimilation, and it provides a pathway to Pt alloy fractionation in the absence of detectable amounts of bulk host-rock assimilation. High Pd/Pt values have been documented in many world-class magmatic sulfide deposits whose parental magmas have demonstrably experienced crustal contamination. Our model suggests that although anomalous Pd/Pt values may be explained by other mechanisms such as incongruent melting of preexisting sulfide or differences in the diffusivities of the metals within achieving equilibration, the assimilation of graphite or methane may play an important role in the global occurrence of magmatic sulfide ores with elevated Pd/Pt values.
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","language":"English","publisher":"American Astronomical Society","doi":"10.3847/PSJ/adbc6c","usgsCitation":"Coyan, J.A., Siegler, M., Martinez-Comacho, J., Beyer, R.A., and Shirley, M., 2025, Prospectivity modeling of the NASA VIPER landing site at Mons Mouton near the Lunar South Pole: Planetary Science Journal, v. 6, no. 5, 105, 9 p., https://doi.org/10.3847/PSJ/adbc6c.","productDescription":"105, 9 p.","ipdsId":"IP-168617","costCenters":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"links":[{"id":487929,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.3847/psj/adbc6c","text":"Publisher Index Page"},{"id":485333,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mons Mouton, Moon","volume":"6","issue":"5","noUsgsAuthors":false,"publicationDate":"2025-04-25","publicationStatus":"PW","contributors":{"authors":[{"text":"Coyan, Joshua Aaron 0000-0002-8450-7364","orcid":"https://orcid.org/0000-0002-8450-7364","contributorId":247291,"corporation":false,"usgs":true,"family":"Coyan","given":"Joshua","email":"","middleInitial":"Aaron","affiliations":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"preferred":true,"id":935581,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Siegler, Matthew A.","contributorId":237898,"corporation":false,"usgs":false,"family":"Siegler","given":"Matthew","middleInitial":"A.","affiliations":[{"id":24584,"text":"PSI","active":true,"usgs":false}],"preferred":false,"id":935582,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Martinez-Comacho, José 0000-0003-0542-7866","orcid":"https://orcid.org/0000-0003-0542-7866","contributorId":354404,"corporation":false,"usgs":false,"family":"Martinez-Comacho","given":"José","affiliations":[{"id":84624,"text":"University of Hawai’i at Manoa, Hawaii Institute for Geophysics and Planetology, 1680 East-West Road, POST Building, Honolulu, HI 96822","active":true,"usgs":false}],"preferred":false,"id":935583,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Beyer, Ross A.","contributorId":204235,"corporation":false,"usgs":false,"family":"Beyer","given":"Ross","email":"","middleInitial":"A.","affiliations":[{"id":36890,"text":"Sagan Center at the SETI Institute and NASA Ames Research Center","active":true,"usgs":false}],"preferred":false,"id":935584,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Shirley, Mark 0000-0001-8767-1760","orcid":"https://orcid.org/0000-0001-8767-1760","contributorId":354405,"corporation":false,"usgs":false,"family":"Shirley","given":"Mark","affiliations":[{"id":84625,"text":"SETI Institute/NASA Ames Research Center","active":true,"usgs":false}],"preferred":false,"id":935585,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ]}