Since 1992, DNR staff have collected water samples as part of each atlas or assessment project. The dataset presently includes data from more than 1,500 samples. The majority of samples have been from wells; other samples were obtained from springs, lakes and other sources. The sites sampled in each project area were selected to include samples from the primary aquifers and were distributed throughout each project area. Samples were analyzed for constituents describing the natural chemistry of the water sample and the parameters groups analyzed generally include primary chemistry, trace elements, tritium, stable isotopes, and carbon-14. Not all parameter groups were analyzed for all samples. Sample analyses did not include contaminant suites of chemicals such as volatile organics or pesticides as the project focus is natural chemistry. The chemistry data for all DNR atlas and assessment projects currently resides in a MS Access database.
The map shows the location of chemistry samples collected by the DNR for county atlas or regional assessment projects. For all atlas and assessment projects please see the county atlas and regional assessment status maps showing all projects in the series.
The following table lists the categories of data that have been collected as part of the DNR County Geologic Atlas and Regional Hydrogeologic Assessment Program and the chemistry data that may be available. Not all parameters were sampled at each site.
The definition of each parameter is described in the Water Chemistry Data Dictionary which lists names and descriptions of fields in the chemistry database. The data dictionary lists all possible chemistry parameters; some data may not be available in specific study areas.
|Chemistry Data Category||Chemistry Data Available|
|Geographic and site information
||Aquifer, location, GPS coordinates, site identifer, site type, project, surface elevation, well depth|
|Measured in the field||Alkalinity, conductivity, dissolved oxygen, oxidation-reduction potential, pH, temperature|
|Cations||Aluminum, barium, calcium, iron, magnesium, manganese, phosphorus, potassium, silicon, sodium, strontium, sulfur|
|Anions||Bromide, chloride, fluoride, nitrate, nitrite, phosphate, sulfate, thiosulfate|
|Trace elements||Antimony, arsenic, beryllium, boron, cadmium, cesium, chromium, cobalt, copper, iodine, lead, lithium, molybdenum, nickel, rubidium, selenium, thallium, tin, titanium, tungsten, uranium, vanadium, zinc, zirconium|
|Isotopes||Carbon-14, deuterium, oxygen-18, tritium|
The chemistry data is provided in six dbf files: geographic and site information; parameters measured in the field; cations; anions; trace elements; and isotopes. To download the desired data, click on the corresponding link below. The data is also provided as a zip file of all six files. The chemistry data available for download is current as of July 2015.
Depending on a user's specific needs, a custom query from the database can be requested. Please contact staff listed below for assistance.
At the completion of each project the MS Access database is updated, the chemistry files for download are updated, and project GIS coverages are made available on the web. These updates occur about once or twice a year. Check the program status map for completed atlas or assessment reports.
Each atlas or assessment prepared by DNR Waters also provides separate Geographic Information System (GIS) files, including a coverage of chemistry data. However, the GIS coverages for the chemistry data are report based and may not in all cases include complete sample data. GIS users interested in a specific project area may first wish to check the project GIS coverage and contents for chemistry ( see the chempt.shp shapefile for each project) to determine if the shapefile contents meets their needs. To access project GIS data, locate the area of interest on the program status map for completed projects.
For more information regarding the atlas program chemistry database and assistance in accessing the data, please contact Todd Petersen, Hydrologist, (651) 259-5698 firstname.lastname@example.org.
Disclaimer: The data are provided "as is" and the Department of Natural Resources does not warrant the accuracy, completeness, or any implied uses of these data.