The Minnesota Department of Natural Resources will collect water samples from about 90 wells in Dakota County to develop the Groundwater Atlas of Dakota County.
The process involves collecting a water sample from an outside spigot or hydrant for laboratory analysis. Dozens of different water components are analyzed to determine the natural chemistry of local aquifers. Participation is voluntary, and owners will receive a report of the laboratory results at no cost. While sampled well locations will appear on atlas maps, contact and ownership information won’t be included.
The DNR will contact selected well owners by mail to request permission to sample their wells. Wells are chosen based on geology, location, well depth and well construction. Participation will help hydrologists create county maps and descriptions of groundwater distribution, movement, conditions, and aquifer pollution sensitivity. The atlas and maps will be printed and shared online, and geographic information system files will be available for download.
Groundwater atlases help identify viable drinking water sources, support sustainability, guide well and septic system construction decisions, inform well-head protection efforts for public water supplies, highlight regional recharge and groundwater movement, and assess pollution sensitivity and possible contaminant migration.
With permission, DNR staff will also collect samples on behalf of the Dakota County Environmental Resources Department for pesticide analysis. The test results will help improve water age dating and assist in determining each aquifer’s sensitivity to pollution. There is no cost for the additional test, and well owners won’t be required to take any action based on their results.
The Groundwater Atlas of Dakota County should be completed in 2028. It will be Part B of a two-part series. Part A, the Geology of Dakota County, was completed by the Minnesota Geological Survey in 2023.
A full description of the Groundwater Atlas program and completed atlas products are available on the program webpage.
Partial funding for the groundwater atlas project is provided by the Minnesota Environment and Natural Resources Trust Fund and the Minnesota Clean Water Legacy Fund.