The Minnesota Department of Natural Resources (DNR) plans to collect water samples from a selection of Cook County wells this summer and fall. Data from the samples will help develop the county’s official groundwater atlas. The DNR Groundwater Atlases are designed to illustrate the state’s underground water resources. They provide detailed, localized frameworks of how groundwater moves, where it is located, and how vulnerable it is to contamination.
The survey process involves collecting a water sample from an outside spigot or hydrant for laboratory analysis. The DNR then analyzes the sample for dozens of water components to determine the chemistry of local aquifers.
The DNR mails a selection of well owners to request permission to sample their wells. Participation is voluntary, and owners receive a report of their individual laboratory results at no cost. Wells are chosen based on geology, location, well depth, and well construction. The atlas and maps will be printed and shared online. The report does not include contact and ownership information.
Groundwater atlases serve as critical decision-making tools for local governments, industry, researchers, and everyday citizens. Because groundwater isn’t visible from the surface, these maps take the guesswork out of water management. The atlases pinpoint the depth, thickness, and lateral extent of local aquifers, helping individuals, drillers, and municipalities identify reliable, sustainable sources of drinking water before they ever break ground.
One of the most valuable aspects of the atlas is mapping the vulnerability of a specific area’s water supply to surface activities. The atlases provide the hard data required to manage local water budgets sustainably. Local planners and property owners use the information to make informed zoning choices, guide the proper placement of residential wells, and safely locate septic systems away from highly sensitive recharge zones. For public water utilities, understanding exactly where their water comes from and the paths it takes to get to the well is a matter of public safety.
Further information can be found on the DNR website at mndnr.gov/groundwatermapping.
