This dataset includes over 49,000 well records from the state well drillers databases in Minnesota, Wisconsin, and Michigan. Each state well has at a minimum the well depth and a static water level. Static water levels were mostly determined when the well was constructed. Data included in this shapefile include the well construction date, well depth, well elevation (if determined), type of well, the methods used for determining the well location and elevation (if determined), casing and screen depths (where reported), the static water level and a date, and the year the well was constructed. The field names from each of the state databases were harmonized to merge the data, and a table of the original field names is included. Tabular files are included with codes describing the original field names mapped to the combined field names, and descriptions of codes used to describe the well location method, well depth method, and well type for each state. The USGS wells in this dataset were pulled from the National Water Information System (NWIS) and have at least one water level measurement. Additional data for the NWIS wells can be retrieved from the USGS National Water Dashboard https://dashboard.waterdata.usgs.gov/app/nwd/en/?region=lower48&aoi=default.

This Open Geospatial Consortium (OGC) GeoPackage (.gpkg) contains water-well point features and associated tables for the state of Minnesota that have been reformatted based on a USGS profile of the OGC GroundWaterML2 (GWML2) standard (https://docs.ogc.org/is/19-013/19-013.html). Additionally, the water-well records have been quality-assured to remove or nullify parts of water-well records found to be erroneous or logically inconsistent, harmonized via the assignment of common data codes in the lithologic log, and supplemented with estimates of transmissivity from the analysis of specific-capacity data. The National Water-Well Database (NWWDB) is a compilation of water-well records from state-managed databases that have been standardized to a common format for consistency across state and administrative boundaries. Water-well completion reports that are submitted to permitting state agencies by licensed drillers constitute a large source of hydrogeologic information, including the locations and distribution of water wells, construction materials and completion depths, lithologic logs, groundwater levels, and the results of pumping or aquifer tests.

This Open Geospatial Consortium (OGC) GeoPackage (.gpkg) contains water-well point features and associated tables for the state of Minnesota that have been reformatted based on a USGS profile of the OGC GroundWaterML2 (GWML2) standard (https://docs.ogc.org/is/19-013/19-013.html). Additionally, the water-well records have been quality-assured to remove or nullify parts of water-well records found to be erroneous or logically inconsistent, harmonized via the assignment of common data codes in the lithologic log, and supplemented with estimates of transmissivity from the analysis of specific-capacity data. The National Water-Well Database (NWWDB) is a compilation of water-well records from state-managed databases that have been standardized to a common format for consistency across state and administrative boundaries. Water-well completion reports that are submitted to permitting state agencies by licensed drillers constitute a large source of hydrogeologic information, including the locations and distribution of water wells, construction materials and completion depths, lithologic logs, groundwater levels, and the results of pumping or aquifer tests.

This Open Geospatial Consortium (OGC) GeoPackage (.gpkg) contains water-well point features and associated tables for the state of Minnesota that have been reformatted based on a USGS profile of the OGC GroundWaterML2 (GWML2) standard (https://docs.ogc.org/is/19-013/19-013.html). The water-well records provided in this data set have not received additional processing or interpretation by the USGS beyond the GWML2 standardization. The National Water-Well Database (NWWDB) is a compilation of water-well records from state-managed databases that have been standardized to a common format for consistency across state and administrative boundaries. Water-well completion reports that are submitted to permitting state agencies by licensed drillers constitute a large source of hydrogeologic information, including the locations and distribution of water wells, construction materials and completion depths, lithologic logs, groundwater levels, and the results of pumping or aquifer tests.

This Open Geospatial Consortium (OGC) GeoPackage (.gpkg) contains water-well point features and associated tables for the state of Minnesota that have been reformatted based on a USGS profile of the OGC GroundWaterML2 (GWML2) standard (https://docs.ogc.org/is/19-013/19-013.html). The water-well records provided in this data set have not received additional processing or interpretation by the USGS beyond the GWML2 standardization. The National Water-Well Database (NWWDB) is a compilation of water-well records from state-managed databases that have been standardized to a common format for consistency across state and administrative boundaries. Water-well completion reports that are submitted to permitting state agencies by licensed drillers constitute a large source of hydrogeologic information, including the locations and distribution of water wells, construction materials and completion depths, lithologic logs, groundwater levels, and the results of pumping or aquifer tests.

This child item contains geology and hydrogeology data used in the hydrogeologic characterization of the Lake Superior watershed and a shapefile of water budget zones for reporting water budget terms for Lake Superior. The geology data include shapefiles of bedrock units from the USGS Geologic map database (Horton, 2017) and surficial geology units from Soller and others (2012). A compilation of hydrogeologic properties (hydraulic conductivity and transmissivity) from a variety of studies in and around the Lake Superior basin and from a field study conducted in 2021 is included in a data table and the values are applied to the bedrock and surficial unit shapefiles. We also include here a zipped grid of simulated groundwater discharge to surface water (rivers and streams) extracted from the Zell and Sanford (2020) MODFLOW6 model of the shallow groundwater in the United States. The sources of data used in the compilation of properties also are included.

This child item contains geology and hydrogeology data used in the hydrogeologic characterization of the Lake Superior watershed and a shapefile of water budget zones for reporting water budget terms for Lake Superior. The geology data include shapefiles of bedrock units from the USGS Geologic map database (Horton, 2017) and surficial geology units from Soller and others (2012). A compilation of hydrogeologic properties (hydraulic conductivity and transmissivity) from a variety of studies in and around the Lake Superior basin and from a field study conducted in 2021 is included in a data table and the values are applied to the bedrock and surficial unit shapefiles. We also include here a zipped grid of simulated groundwater discharge to surface water (rivers and streams) extracted from the Zell and Sanford (2020) MODFLOW6 model of the shallow groundwater in the United States. The sources of data used in the compilation of properties also are included.

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 samples from 10 wells between July 1996 to May 1997. Groundwater ages were estimated from dissolved gas (neon, argon, krypton, and xenon) and environmental tracer data (tritium, sulfur hexafluoride, chlorofluorocarbons, and tritiogenic helium-3) from field samples using the equations available in TracerLPM (an Excel® workbook for interpreting groundwater age distributions from environmental tracer data) and DGMETA (an Excel® workbook for dissolved gas modeling and environmental tracer analysis); groundwater age estimates are reported in Table_1_Age_Information.txt. DGMETA was used to compute the optimal water temperature, excess air, entrapped air, fractionation of gases, and excess nitrogen gas (mainly from denitrification) for the measured dissolved gases in a sample; condensed results are reported in Table_1_Age_Information.txt and these results are reported in detail in Table_2_Dissolved_Gases.txt. These values were then used to convert the raw measured concentrations of environmental tracers into a form appropriate for age dating analysis; these results are reported in Table_3_Computed_Tracer_Concentrations.txt. Calculated concentrations of environmental tracers that were used in groundwater age calculations are the dry air mixing ratio of sulfur hexafluoride or chlorofluorocarbons, and tritiogenic helium-3, which is the concentration of helium-3 from the decay of tritium. Table_4_Site_And_Background_Information.txt reports additional site information and field parameters. In addition to these four tables, two ancillary tables are included to provide more detailed information about the fields and the abbreviations used in tables 1-4. A readme file is provided that describes each table in more detail and processes to use the data in this data release to view age distributions in TracerLPM and to set up TracerLPM to run scenarios for other chemicals of interest.

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 samples from 10 wells between July 1996 to May 1997. Groundwater ages were estimated from dissolved gas (neon, argon, krypton, and xenon) and environmental tracer data (tritium, sulfur hexafluoride, chlorofluorocarbons, and tritiogenic helium-3) from field samples using the equations available in TracerLPM (an Excel® workbook for interpreting groundwater age distributions from environmental tracer data) and DGMETA (an Excel® workbook for dissolved gas modeling and environmental tracer analysis); groundwater age estimates are reported in Table_1_Age_Information.txt. DGMETA was used to compute the optimal water temperature, excess air, entrapped air, fractionation of gases, and excess nitrogen gas (mainly from denitrification) for the measured dissolved gases in a sample; condensed results are reported in Table_1_Age_Information.txt and these results are reported in detail in Table_2_Dissolved_Gases.txt. These values were then used to convert the raw measured concentrations of environmental tracers into a form appropriate for age dating analysis; these results are reported in Table_3_Computed_Tracer_Concentrations.txt. Calculated concentrations of environmental tracers that were used in groundwater age calculations are the dry air mixing ratio of sulfur hexafluoride or chlorofluorocarbons, and tritiogenic helium-3, which is the concentration of helium-3 from the decay of tritium. Table_4_Site_And_Background_Information.txt reports additional site information and field parameters. In addition to these four tables, two ancillary tables are included to provide more detailed information about the fields and the abbreviations used in tables 1-4. A readme file is provided that describes each table in more detail and processes to use the data in this data release to view age distributions in TracerLPM and to set up TracerLPM to run scenarios for other chemicals of interest.

These data include base flow separation estimates for 64 USGS streamflow gages in the Lake Superior watershed from 1945 to 2020, shapefiles of the gaging stations and watersheds for each gaging station, and a zipped folder of graphics of the base flow separation results. The base flow separation estimates were calculated using the U.S. Geological Survey Groundwater Toolbox (Barlow and others, 2014) for any complete water years of record for these gages from 1945 to 2020. The shapefile of the gaging stations includes the starting and ending years of data for each station, the number of years of record. The watersheds shapefile includes the source for the watershed delineation, the watershed area, and the number of upstream and(or) downstream gaging stations on the same river system. If there are upstream gaging stations in the river system, the watershed delineated is only the incremental part of the watershed between gaging stations. The baseflow separation estimates for each gaging station include daily, monthly, and annual output from the Groundwater Toolbox for six estimation methods included in the software (full references are available in Barlow and others, 2014): the baseflow Index-Standard method, HySep Fixed Interval, HySep Local Minimum, HySep Sliding Interval, baseflow Index-Modified, PART, and BFLOW. A summary of the annual baseflow estimates for all the gaging stations using all the methods is provided also is included in this data release. This data release is one of three child items under the overall data release at https://doi.org/10.5066/P9084UKQ.