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Filters: Tags: Groundwater age (X) > Types: OGC WFS Layer (X)

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The Captain Jack Superfund site near Ward, Colorado hosts extensive interconnected underground mine workings, which drain via the Big Five Adit. Drainage from the adit has historically been acidic with elevated concentrations of metals. In 2018 the U.S. Environmental Protection Agency (EPA) utilized a subsurface remediation strategy consisting of the installation of a hydraulic bulkhead within the workings to preclude drainage out of the mine. To understand the processes occurring during water impoundment within the mine workings, the U.S. Geological Survey (USGS), in cooperation with EPA, completed water-quality sampling and analysis during 2020 as water was impounded within the mine workings. The USGS sampling...
The U.S. Geological Survey collected groundwater samples from 17 wells in the Indio subbasin (CA basin designation 7-21.01) of the Coachella Valley and surface water samples from two sites representing sources of recharge to the Indio subbasin in 2021. These samples are intended to provide inorganic water quality data, particularly total dissolved solids (TDS), within areas of the Indio subbasin not sampled for the Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project’s assessment of the quality of groundwater used for domestic and small system drinking water supplies in Coachella Valley (CODA). Other areas of special interest for the Indio salinity study were nearby managed aquifer...
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Residence time distribution (RTD) is a critically important characteristic of groundwater flow systems; however, it cannot be measured directly. RTD can be inferred from tracer data with analytical models (few parameters) or with numerical models (many parameters). The second approach permits more variation in system properties but is used less frequently than the first because large-scale numerical models can be resource intensive. With the data and computer codes in this data release users can (1) reconstruct and run 115 General Simulation Models (GSMs) of groundwater flow, (2) calculate groundwater age metrics at selected GSM cells, (3) train a boosted regression tree model using the provided data, (4) predict...
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A multivariate regression model was developed to predict zero-order oxygen reduction rates (mg/L/yr) in aquifers across the State of Wisconsin. The model used a combination of dissolved oxygen concentrations and mean groundwater ages estimated with sampled age tracers from wells in the U.S. Geological Survey National Water Information System and previously published project reports from state agencies and universities. The multivariate regression model was solved using the Microsoft Excel solver, with 461 wells used for training and 46 wells held-out for validation. A total of 31 predictor variables were used for model development (56 were tested), including basic well characteristics, soil properties, aquifer properties,...
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Thirty water-supply drinking-water wells were sampled during fall 2018 for a set of constituents including PFAS. Groundwater samples were sent to Maxxam Laboratories (RTI Laboratory contract) to be analyzed for eighteen PFAS using USEPA 537m method. Groundwater age data were collected and analyzed as well in the USGS Reston, Va. laboratory. Quality-control samples including equipment and field blanks, sequential replicate samples, and laboratory spikes, were collected to evaluate and estimate potential contamination bias and measure variability from water-quality data-collection processes. No PFAS were detected in equipment or field blanks indicating that selected equipment, cleaning, sampling, and handling procedures...
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This data release provides additional data collected since the original publication of: Busenberg, Eurybiades, Plummer, L.N., Coplen, T.B., Doughten, M.W., Widman, P.K., Casile, G.C., Wayland, J.E., and Nelms, D.L., 2014, A 19-year record of chemical and isotopic composition of water from springs of the Shenandoah National Park, Virginia, 1995–2014: U.S. Geological Survey Data Series 893, 11 p., http://dx.doi.org/10.3133/ds893. ISSN 2327-638X (online) This data release represents to original 2014 U.S. Geological Survey Data Series along with additional data collected in Shenandoah National Park up to April 18, 2017. The data release consists of two files: a spreadsheet consisting of multiple worksheets, and a data...
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The Mississippi River Valley alluvial aquifer (MRVA) overlies and is bounded by several regional aquifers that make up the Mississippi embayment aquifer system (MEAS) in the central United States. The MRVA, which consists of Quaternary alluvium, is one of the most heavily pumped aquifers in the nation and is a major source of groundwater for irrigation. Large groundwater-level declines in portions of the aquifer have raised concerns about sustainable use of this important resource. An aquifer-scale assessment of groundwater-age categories based on tritium concentrations was completed to better understand groundwater availability and susceptibility. The presence of tritium, a radioactive isotope of hydrogen, in a...
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This data release documents three Microsoft Excel tables; one contains noble gas isotopic data, one contains data for understanding groundwater ages in the South Rim of the Grand Canyon, and one that describe the data fields. Results described include raw noble gas concentrations, environmental tracer concentrations (tritium, tritiogenic helium-3, sulfur hexafluoride, carbon-14, and chlorofluorocarbons), and mean age and age distribution. Noble gas isotopes (NobleGas) contain noble gas isotope concentrations measured for South Rim springs. Samples were collected in pinch clousure copper tubes (Weiss, 1968) and analyzed at the University of Utah Dissolved Gas Lab. Mean age and age distribution...
    map background search result map search result map A multi-year record of chemical and isotopic composition of water from springs of the Shenandoah National Park, Virginia Noble gas isotopes and lumped parameter model results for environmental tracer based groundwater ages, South Rim Grand Canyon, Arizona, USA Data for three-dimensional distribution of groundwater residence time metrics in the glaciated United States using metamodels trained on general numerical simulation models Groundwater age categories based on tritium concentrations in samples collected from the Mississippi River Valley alluvial aquifer and aquifers of the Mississippi embayment principal aquifer system Data in support of the occurrence and distribution of per- and polyfluoroalkyl substances in sampled source water of public drinking-water supplies in the surficial aquifer in Delaware, 2018 Hydrologic and Geochemical Data and Models Supporting Integrated Evaluation of the Captain Jack Superfund Site, Boulder County, Colorado Groundwater and surface water data for a regional assessment of groundwater salinity variations and sources in the Indio Subbasin of the Coachella Valley, California Multivariate regression model for predicting oxygen reduction rates in groundwater for the State of Wisconsin Hydrologic and Geochemical Data and Models Supporting Integrated Evaluation of the Captain Jack Superfund Site, Boulder County, Colorado A multi-year record of chemical and isotopic composition of water from springs of the Shenandoah National Park, Virginia Groundwater and surface water data for a regional assessment of groundwater salinity variations and sources in the Indio Subbasin of the Coachella Valley, California Data in support of the occurrence and distribution of per- and polyfluoroalkyl substances in sampled source water of public drinking-water supplies in the surficial aquifer in Delaware, 2018 Noble gas isotopes and lumped parameter model results for environmental tracer based groundwater ages, South Rim Grand Canyon, Arizona, USA Multivariate regression model for predicting oxygen reduction rates in groundwater for the State of Wisconsin Groundwater age categories based on tritium concentrations in samples collected from the Mississippi River Valley alluvial aquifer and aquifers of the Mississippi embayment principal aquifer system Data for three-dimensional distribution of groundwater residence time metrics in the glaciated United States using metamodels trained on general numerical simulation models