The Minnesota Department of Agriculture (MDA) offered free nitrate well testing for the first time at Farmfest this year, giving well owners instant answers about their drinking water. Over the three-day event, 107 private wells were tested. Six exceeded the federal health standard of 10 milligrams per liter (mg/L) nitrate-nitrogen, and another nine showed elevated levels between 5 and 10 mg/L. About three in four Minnesotans rely on groundwater for their drinking water—making its protection a statewide concern.
“Unsafe nitrate levels can be a hidden danger in Minnesota well water,” said MDA Commissioner Thom Petersen. “At Farmfest, we uncovered those risks and gave families immediate answers to protect themselves.”
The MDA is charged with monitoring nitrogen fertilizer use under the state’s Groundwater Protection Rule, which addresses nitrate levels in public wells and restricts the application of fertilizer in the fall and on frozen soils.
Nitrate in drinking water is a serious health concern—especially for infants under 6 months of age and pregnant women. Nitrate is undetectable through smell or taste. Testing is required to determine if it’s present—and at what level. The Minnesota Department of Health recommends that wells be tested annually for nitrate and other contaminants.
Under Minnesota’s Groundwater Protection Act, the MDA oversees nitrogen fertilizer use and management and has developed the Nitrogen Fertilizer Management Plan to help prevent or minimize nitrate impacts. At Farmfest, some families learned for the first time that their water was unsafe because of shallow, poorly constructed wells, well proximity to crop fields or manure, and geology—such as the fractured limestone in southeast Minnesota’s karst region—which are the most common factors in nitrate contamination.
“One young family with a newborn learned their water wasn’t safe,” said Denton Bruening, a water-quality expert who led the testing clinic. “They left our booth with both answers and options—that’s the power of this program.”
For wells with elevated nitrate, MDA staff offered on-the-spot guidance, including treatment options such as reverse osmosis or distillation, and in some cases recommended alternative water supplies.
The MDA has tested tens of thousands of wells statewide since first offering free nitrate testing more than 30 years ago. In 2024, more than 2,400 wells were tested, with 6% exceeding the health standard. Beyond testing, the program connects well owners with practical solutions—whether to continue monitoring, treat their water, or consider a new well.
“The response at Farmfest shows how valuable this service is,” Petersen added. “Every Minnesotan deserves safe drinking water, and free clinics like this are one way we make that a reality.”
The MDA maintains nitrate testing equipment statewide in partnership with local Soil and Water Conservation Districts and organizations such as the Minnesota Well Owners Organization. Community groups, counties, and lake associations interested in hosting clinics are encouraged to reach out to the MDA. For more information or to learn how to host a nitrate testing clinic in your community, contact Denton Bruening at 651-261-1993 or Travis Hirman at 612-201-4194.
###
Media Contact
Cynthia Moothart, MDA Communications
651-420-2637
Cynthia.Moothart@state.mn.us
