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This data set includes results for hormone and pharmaceutical compounds analyzed in environmental and quality-control samples collected by the USGS National Water-Quality Assessment Project during 2013 through 2015 for a study of groundwater resources used for drinking-water supply across the United States. Hormone and pharmaceutical results are provided for environmental samples collected at 1,120 wells or springs; selected ancillary data, such as principal aquifer, well depth, and land-use information also are provided for the sampled sites. The types of quality-control samples included in this data set are blanks, matrix spikes, and replicates collected at field sites or field offices. Included in this data...
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Water-quality data for groundwater samples collected from 4,824 sites between 1991 through 2018, and ancillary data and information on sampled wells and principal aquifers, were used to assess the occurrence and distribution of strontium in U.S. groundwater from 32 principal aquifers. This data release includes one tab-delimited text file detailing these data. Table: Chemical data from the U.S. Geological Survey National Water Information System and ancillary data considered for assessment of strontium concentration in U.S. groundwater.
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Concentrations of inorganic constituents, dissolved organic carbon (DOC), tritium, per- and polyfluoroalkyl substances (PFAS), volatile organic compounds (VOCs), and pharmaceuticals were measured in groundwater samples collected from 254 wells in 2019 and 2020. Concentrations of inorganic constituents, DOC, VOCs, and pharmaceuticals were measured at the U.S. Geological Survey (USGS) National Water Quality Laboratory in Lakewood, Colorado. Concentrations of tritium were measured at the USGS Tritium Laboratory in Menlo Park, California. Concentrations of PFAS were measured at SGS Laboratory in Orlando, Florida. In addition, several geospatial parameters were determined, including: percentages of selected land uses...
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Groundwater quality data were collected in 5,000 wells between 1988-2001 by the National Water-Quality Assessment Project. About 1,500 of these wells were sampled again between 2002-2012 to evaluate decadal changes in groundwater quality. Monitoring wells, domestic supply wells, and some public supply wells were included in this study. All water was collected prior to treatment. Groundwater samples used to evaluate decadal change were collected from networks of wells with similar characteristics. Some networks, consisting of domestic or public supply wells, were used to assess changes in the quality of groundwater used for drinking water supply. Other networks, consisting of monitoring wells, assessed changes in...
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Data provided here describe geochemical correction of carbon-14 in dissolved inorganic carbon (DIC) for groundwater age dating. Datasets include major ion chemistry of groundwater samples, model parameter inputs, and final corrected carbon-14 in DIC. Geochemical correction was completed in two phases: determination of reactive phase mole transfers through an inverse geochemical model (PHREEQC; Parkhurst and Appleo, 1992) and tracking of isotopic mass transfer among phases (NetpathXL; Parkhusrtand Charlton, 2008). Parkhurst, D.L., and Appelo, C.A.J., 2013, Description of input and examples for PHREEQC version 3—A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical...
Tags: Cenozoic, Connecticut, Holocene, Idaho, Illinois, All tags...
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This data release documents nine Microsoft Excel tables that contain data for understanding groundwater ages in the Glacial aquifer system. Results for the three sample networks (PAS, principal aquifer study; MSS, modeling support study; FPS, flow path study) are described by three tables each: dissolved gas modeling results, environmental tracer concentrations (tritium, tritiogenic helium-3, sulfur hexafluoride, carbon-14, and radiogenic helium-4), and results for the mean age and age distribution. Tables are labeled by network and data type (as described below) separated by an underscore (_). For example, dissolved gas modeling results from the PAS network is label ‘PAS_NGmodel’. Dissolved gas modeling results...
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This data release documents eight Microsoft Excel tables; four which contain data for understanding groundwater ages in the South East Coastal Plain (SECP), Coastal Lowlands (CLOW) and Mississippi Embayment and Texas Coastal Uplands (METX) aquifer systems and four that describe the data fields. Results described include dissolved gas modeling results, environmental tracer concentrations (tritium, tritiogenic helium-3, sulfur hexafluoride, and radiogenic helium-4), mean age and age distribution, and carbon-14 geochmical modeling results Dissolved gas modeling results (DGmodel) contains detailed information on the calibration of dissolved gas models to dissolved gas concentrations (neon, argon, krypton, xenon, and...
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Galvanic corrosion of lead in water distribution systems can occur when lead pipe or lead solder is in contact with a dissimilar metal such as copper. If the source water entering those systems has a relatively elevated chloride-to-sulfate mass ratio (CSMR), the potential for galvanic corrosion to occur is elevated (Gregory 1985; Edwards and Triantafyllidou, 2007), especially in water with low values of alkalinity (Nguyen and others, 2011). Values of CSMR were computed for untreated groundwater samples from 26,631 locations in the United States. Three levels, identified by Nguyen and others (2011), were used to classify CSMR values relative to their potential for promoting galvanic corrosion of lead. The three-level...
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This data set includes sample information and results for third-party performance assessment samples analyzed for hormones and pharmaceuticals during the same general time period as environmental samples collected by the National Water-Quality Assessment (NAWQA) Project for a study of groundwater resources used for drinking-water supply across the United States, 2013 through 2015. Hormone and pharmaceutical results are provided for spiked and unspiked samples submitted by the Quality Systems Branch (QSB) Organic Blind Sample Project (OBSP), providing information regarding analyte recovery and occurrence of false positive and false negative results. Included in this data release are the following data tables: Table...
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Continuous monitoring and discrete water-quality sampling were coupled in a karst aquifer to assess drivers and timescales of water-quality change. Water-quality data included environmental tracers of groundwater age (tritium [3H], tritiogenic helium-3 [3He-trit], sulfur hexafluoride [SF6], carbon-14 [14C], and radiogenic helium-4 [4He-rad]). All water quality data is available from the U.S. Geological Survey NWIS database (U.S. Geological Survey, 2019). Groundwater ages were estimated by calibration of environmental tracers to lumped parameter models of groundwater age for multiple samples collected at six groundwater wells using the program TracerLPM (Jurgens and others, 2012). The final estimates for mean groundwater...
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A boosted regression tree (BRT) model was developed to predict pH conditions in three-dimensions throughout the glacial aquifer system (GLAC) of the contiguous United States using pH measurements in samples from 18,258 wells and predictor variables that represent aspects of the hydrogeologic setting. Model results indicate that the carbonate content of soils and aquifer materials strongly controls pH and when coupled with long flow paths, results in the most alkaline conditions. Conversely, in areas where glacial sediments are thin and carbonate-poor, pH conditions remain acidic. At depths typical of drinking-water supplies, predicted pH > 7.5 – which is associated with arsenic mobilization – occurs more frequently...
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This data release documents three Microsoft Excel tables that contain data for understanding environmental tracer concentrations in groundwater of the High Plains aquifer system. Results of dissolved-gas modeling using environmental tracer concentrations (tritium, tritiogenic helium-3, and radiogenic helium-4), for the sample network (VPFS, vertical flow path study) are described. Dissolved gas modeling results (ModOut) contains detailed information on the calibration of dissolved gas models to measured dissolved-gas concentrations (neon, argon, krypton, xenon, and nitrogen). Calibration was done using methods described by Aeschbach-Hertig and others (1999 & 2000) with modifications to include nitrogen gas (Weiss,...
Groundwater-quality data were collected from 648 wells as part of the National Water-Quality Assessment Project of the U.S. Geological Survey National Water-Quality Program and are included in this report. Most of the wells (514) were sampled from January through December 2016 and 60 of them were sampled in 2013 and 74 in 2014. The data were collected from seven types of well networks: principal aquifer study networks, which are used to assess the quality of groundwater used for public water supply; land-use study networks, which are used to assess land-use effects on shallow groundwater quality; major aquifer study networks, which are used to assess the quality of groundwater used for domestic supply; enhanced...
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This data release consists of data (in four tables) for assessing the time scales of arsenic variability in three production wells in New Hampshire; tables that describe the data fields in the data tables are also included in the data release. High-frequency (every 5 to 15 minutes) and bi-monthly water-quality monitoring of a bedrock-aquifer domestic well (425651070573701), a bedrock-aquifer public-supply well (425400070545401), and a glacial-aquifer public-supply well (425311070535801) was completed between 2014 and 2018. Concentrations of arsenic and other geochemical constituents and dissolved gases, as tracers of groundwater age, were measured on a bimonthly basis; physicochemical data, including specific conductance,...
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Samples for analysis were selected from 1) archived rotosonic cores drilled by the Minnesota Geological Survey and archived at the Lands and Minerals Drill Core Library, Minnesota Department of Natural Resources, Hibbing, Minnesota, USA; or b) freshly collected rotosonic cores, collected on-site at the time of coring. Cores in the sample archive are stored in wooden core-boxes in ambient air. Cores have supporting geology, stratigraphy, geochemistry, and hydrogeology data as published in County Geologic Atlases, Parts A and B, by the Minnesota Geological Survey (MGS) and the Minnesota Department of Natural Resources (MDNR); or in Regional Hydrogeologic Assessments, MGS. Included in this data release are: Core_Chem_Locations.pdf:...
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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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Lithium concentrations in untreated groundwater from 1,464 public-supply wells, 1,676 domestic-supply wells, and 1,560 monitoring wells distributed across 33 principal aquifers in the United States were evaluated for spatial variations and possible explanatory factors. For context, lithium concentrations are compared to a drinking-water only threshold (60 micrograms per liter) and a Health-Based Screening Level (HBSL, 10 micrograms per liter). These thresholds were exceeded in 9% and 45% of samples from public-supply wells and in 6% and 37% from domestic-supply wells, respectively. Exceedances were most frequent for arid regions and older groundwater. Groundwater lithium concentrations were highest in unconsolidated...
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Categorical classification of groundwater age based on concentrations of tritium (3H) in groundwater can provide useful information for the assessment and understanding of groundwater resources. These data present a three-part groundwater age classification system for the continental United States based on tritium thresholds that vary in space and time: modern (recharged after 1952), if the measured value is larger than an upper threshold; premodern (recharged prior to 1953) if the measured value is smaller than a lower threshold; or mixed if the measured value is between the two thresholds. Inclusion of spatially-varying that vary geographically on the basis of the location of the sample rather than a single threshold...
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Evaluating Decadal Changes in Groundwater Quality: Groundwater quality data were collected from 5,000 wells between 1988-2001 by the National Water-Quality Assessment Project. Samples are collected in groups of 20-30 wells with similar characteristics called networks. About 1,500 of these wells in 67 networks were sampled about 10 years later between 2002-2012 (second sampling event) to evaluate decadal changes in groundwater quality. Between 2012 and 2016 (third sampling event), a subset of these networks has been sampled again, allowing additional results to be displayed on the web page: Decadal changes in groundwater quality. This is the third iteration of data added to the website, so this data release is referred...
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Three wells in New Hampshire were sampled bimonthly over three years to evaluate the temporal variability of arsenic concentrations and groundwater age. All samples had measurable concentrations of arsenic throughout the entire sampling period and concentrations in individual wells varied, on average, by more than 7 µg/L. High arsenic concentrations (>10 µg/L) were measured in wells KFW-87 and SGW-93, consistent with the high pH and low dissolved oxygen typically found in bedrock wells. Lower arsenic concentrations (< 10 µg/L) at well SGW-65 were consistent with lower pH typical of the glacial aquifer. The well producing the oldest water, public bedrock well SGW-93, was not the well with the highest arsenic concentrations;...


map background search result map search result map Classification of Chloride-to-Sulfate Mass Ratio for U.S. Groundwater With Respect to the Potential to Promote Galvanic Corrosion of Lead, 1991-2015; Water Well Data and Characteristic Values for States Data from Decadal Change in Groundwater Quality Web Site, 1988-2012 Geochemical Correction of Carbon-14 in Dissolved Inorganic Carbon used for Groundwater Age Dating in the Glacial Aquifer System, Conterminous United States Dissolved Gas, Environmental Tracer Concentrations, and Lumped Parameter Modeling Results for Groundwater Age Dating in the Glacial Aquifer System, Conterminous United States Data for Arsenic Variability and Groundwater Age in Three Water-Supply Wells in Southeast New Hampshire Environmental and Quality-Control Data Collected by the USGS National Water-Quality Assessment Project for Hormones and Pharmaceuticals in Groundwater Used as a Source of Drinking Water Across the United States, 2013-15 Third-party performance assessment data encompassing the time period of analysis of groundwater samples collected for hormones and pharmaceuticals by the National Water-Quality Assessment Project in 2013-15 Data for Groundwater Age and Susceptibility of Poorly Consolidated Sedimentary Aquifers of the United States Gulf Coast: Results from the Southeast Coastal Plain (SECP), Coastal Lowland (CLOW), Mississippi Embayment and Texas Coastal Upland (METX) Principal Aquifer Networks Data for Tritium as an Indicator of Modern, Mixed and Premodern Groundwater Age Data for timescales of water-quality change in a karst aquifer, south-central Texas Data from Decadal Change in Groundwater Quality Web Site, 1988-2016 Data for Time Scales of Arsenic Variability and the Role of High-Frequency Monitoring at Three Water-Supply Wells in New Hampshire, USA Dissolved Gas and Tracer Concentrations for the High Plains Aquifer, Vertical Flowpath Study Network Till geochemistry from rotosonic cores in Minnesota, USA Data for three-dimensional distribution of groundwater residence time metrics in the glaciated United States using metamodels trained on general numerical simulation models Data for machine learning predictions of pH in the glacial aquifer system, northern USA Data for the occurrence and distribution of strontium in U.S. groundwater Inorganic Constituent and Ancillary Data for Evaluation of Lithium in Groundwater in the United States, 1991-2018 Geochemical and Geospatial Data for Per- and Polyfluoroalkyl Substances (PFAS) in Groundwater Used as a Source of Drinking Water in the Eastern United States Data for Arsenic Variability and Groundwater Age in Three Water-Supply Wells in Southeast New Hampshire Data for Time Scales of Arsenic Variability and the Role of High-Frequency Monitoring at Three Water-Supply Wells in New Hampshire, USA Data for timescales of water-quality change in a karst aquifer, south-central Texas Dissolved Gas and Tracer Concentrations for the High Plains Aquifer, Vertical Flowpath Study Network Till geochemistry from rotosonic cores in Minnesota, USA Data for Groundwater Age and Susceptibility of Poorly Consolidated Sedimentary Aquifers of the United States Gulf Coast: Results from the Southeast Coastal Plain (SECP), Coastal Lowland (CLOW), Mississippi Embayment and Texas Coastal Upland (METX) Principal Aquifer Networks Geochemical and Geospatial Data for Per- and Polyfluoroalkyl Substances (PFAS) in Groundwater Used as a Source of Drinking Water in the Eastern United States Dissolved Gas, Environmental Tracer Concentrations, and Lumped Parameter Modeling Results for Groundwater Age Dating in the Glacial Aquifer System, Conterminous United States Geochemical Correction of Carbon-14 in Dissolved Inorganic Carbon used for Groundwater Age Dating in the Glacial Aquifer System, Conterminous United States Data for machine learning predictions of pH in the glacial aquifer system, northern USA Data for three-dimensional distribution of groundwater residence time metrics in the glaciated United States using metamodels trained on general numerical simulation models Data for Tritium as an Indicator of Modern, Mixed and Premodern Groundwater Age Environmental and Quality-Control Data Collected by the USGS National Water-Quality Assessment Project for Hormones and Pharmaceuticals in Groundwater Used as a Source of Drinking Water Across the United States, 2013-15 Third-party performance assessment data encompassing the time period of analysis of groundwater samples collected for hormones and pharmaceuticals by the National Water-Quality Assessment Project in 2013-15 Data from Decadal Change in Groundwater Quality Web Site, 1988-2012 Data from Decadal Change in Groundwater Quality Web Site, 1988-2016 Inorganic Constituent and Ancillary Data for Evaluation of Lithium in Groundwater in the United States, 1991-2018 Data for the occurrence and distribution of strontium in U.S. groundwater Classification of Chloride-to-Sulfate Mass Ratio for U.S. Groundwater With Respect to the Potential to Promote Galvanic Corrosion of Lead, 1991-2015; Water Well Data and Characteristic Values for States