Homes on private wells in Minnesota
In about 20% of Minnesota homes, drinking water comes from a private well. People may also drink well water at a secondary home or seasonal property, like a cabin. While community water systems are routinely tested to make sure the drinking water meets safety standards, private wells present an increased risk of exposure to water contaminants because they are not required to be tested after initial construction. Both natural sources and human activities may contaminate private well water and could lead to short- or long-term health effects. You cannot taste, see, or smell most water contaminants - the only way to know if well water is safe to drink is to test the water.
Nitrate is one of the most common contaminants in groundwater. Consuming too much nitrate can be harmful—especially for babies. While nitrate can get into groundwater from many sources such as livestock waste, leaky sewer lines, or septic tank effluent, research has shown that agricultural fertilizer use is a major contributor to groundwater contamination in Minnesota. Private wells are at higher risk if they are located in a geologically vulnerable area, where nitrate can more easily move through soil and into groundwater. The Minnesota Department of Agriculture works to minimize nitrogen fertilizer impacts on groundwater.
Data at a glance
On this page you can explore:
- The estimated number and percent of homes on private wells by county and census tract.
- The estimated number and percent of homes on private wells at increased nitrate contamination risk by county and census tract.
What should I do to protect my health if my drinking water comes from a private well?
Minnesota Department of Health recommends that you regularly inspect your well, test your water quality, and treat your water when necessary.
- Visit the Owner’s Guide to Wells for an overview of how to ensure safe drinking water through regular maintenance and inspection.
- Visit Well Testing, Results, and Options for more information on how to test your well water and what to do with your test results.
- Well owners in southeast Minnesota may be eligible for free nitrate testing through MDH and the Tap-In Collaborative by going to the Well Tested? Well Done SE Minnesota Webpage. If test results show high nitrate levels (greater than 10 milligrams per liter), residents in southeast Minnesota can apply for a water treatment system at no cost through the Tap-In Collaborative.