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Groundwater age distributions and susceptibility to natural and anthropogenic contaminants were assessed for selected wells, streambed piezometers, and springs in southeastern Minnesota. The data provide information to understand how long it will take to observe groundwater quality improvements from best management practices implemented at land surface to reduce losses of nitrate (and other chemicals) from agricultural practices. Nineteen water samples were collected from ten wells, three streambed piezometers, and four springs between August 2020 and September 2022. Two of these samples are field replicate samples collected from a spring site and a well site. A child item contains historical data from 15 water...
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We computed mean groundwater ages and age distributions at eight wells by calibrating lumped parameter models (LPMs) to concentrations of tracers (3H, CFCs, SF6) in samples using the computer program TracerLPM (Jurgens and others, 2012). We also measured 14C but all samples contained ancient carbonate from the limestone bedrock, and we were unable to resolve the atmospherically-derived 14C sufficiently to use it as a tracer. Tritium was below the detection level in two of the eight well-water samples, indicating the water was recharged prior to about 1950. Groundwater from the other six wells could be fitted to LPMs that were either piston flow models (PFM), exponential – piston flow models (EPM), or binary mixing...
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Groundwater age distributions and susceptibility to natural and anthropogenic contaminants were assessed for selected wells across Minnesota. The data provide information to understand how long it will take to observe groundwater quality improvements from best management practices implemented at land surface to reduce losses of nitrate (and other chemicals) from agricultural practices. A total of 13 age estimates were done on samples collected from 8 wells between July 1996 and May 1997. Groundwater ages were estimated from dissolved gas (argon and nitrogen) and environmental tracer data (tritium, chlorofluorocarbons, and tritiogenic helium-3) from field samples using the equations available in TracerLPM (an Excel®...
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The U.S. Geological Survey (USGS), in cooperation with the Bureau of Reclamation, began hydrogeologic investigations in 2009 in the Paradox Valley in Colorado. In June 2011, nine groundwater samples were collected from selected wells and springs in the study area. The samples were analyzed for a suite of environmental tracers and dissolved gases that were used to model recharge temperatures and groundwater ages. All geochemical and environmental tracer results used in the models are available in the USGS National Water Information System (NWIS) using USGS station numbers. This data release presents the data and modeling results in four CSV files. The file C14_age_models.csv presents laboratory results for carbon-14...
    map background search result map search result map Groundwater Age-Tracing Data and Models in a PFOA-Contaminated Bedrock Aquifer, North Bennington, Vermont Groundwater data and age information from samples collected in Minnesota (ver. 2.0, January 2024) Recharge temperatures and groundwater-age models for the Paradox Valley alluvial aquifer, 2011, Colorado Groundwater data and age information from samples collected in Minnesota, 1996-1997 Groundwater Age-Tracing Data and Models in a PFOA-Contaminated Bedrock Aquifer, North Bennington, Vermont Recharge temperatures and groundwater-age models for the Paradox Valley alluvial aquifer, 2011, Colorado Groundwater data and age information from samples collected in Minnesota, 1996-1997 Groundwater data and age information from samples collected in Minnesota (ver. 2.0, January 2024)