Private wells in Southeast Minnesota

Nitrate is a health concern in some private wells in southeast Minnesota

 

Addressing nitrate in private wells in southeast MN 

This webpage provides private well test results for nitrate in Dodge, Fillmore, Goodhue, Houston, Mower, Olmsted, Wabasha, and Winona counties (referred to as Southeast Minnesota). It also includes key metrics to measure the State of Minnesota’s progress in implementing their work plan for Addressing Nitrate in Southeast Minnesota. Learn more about this work plan and why it exists at Response to EPA Nitrate Letter for Southeast Minnesota. 

How to protect yourself and your family 

If your drinking water comes from a private well, you should test for nitrate every year. 

Drinking water with levels of nitrate at or below 10 mg/L is considered safe for everyone. If you get your water from a public water system, your system makes sure that the nitrate concentration is at or below 10 mg/L.  

Health effects of nitrate 

Nitrate is a compound that naturally occurs and has many human-made sources. Consuming too much nitrate can affect how blood carries oxygen and can cause methemoglobinemia (also known as blue baby syndrome). Bottle-fed babies under six months old are at the highest risk of getting methemoglobinemia. Methemoglobinemia can cause skin to turn a bluish color and can result in serious illness or death.  

Only recently has scientific evidence emerged to assess the health impacts of drinking water with high nitrate on adults. A growing body of literature indicates potential associations between nitrate/nitrite exposure and other health effects such as increased heart rate, nausea, headaches, and abdominal cramps. Some studies also suggest an increased risk of cancer, especially gastric cancer, associated with dietary nitrate/nitrite exposure, but there is not yet scientific consensus on this question. 

Nitrate is a health concern in some private well water in southeast Minnesota 

Data from the Southeast Minnesota Water Analysis laboratory show that 5.1% of private wells in Southeast Minnesota that have tested through the laboratory since 2016 have a nitrate concentration at or above 10 mg/L. Results are updated quarterly. 

The data also show that 15.6% have a nitrate concentration above 3 mg/L (but less than 10 mg/L). While those levels are below the 10 mg/L standard for drinking water, they do suggest human-made sources of nitrate have gotten into the water and the level could increase over time. Testing the water every year is important. 

Finally, the data show that 79.3% have a nitrate concentration below 3 mg/L or is not detected.  

Measuring progress  

Minnesota has a robust work plan to address nitrate in southeast Minnesota, including offering free well testing and mitigation for eligible households and conducting a well inventory. We are doing this work in phases. As we add components to the work, we will add measures to show how the work is advancing. 

Data source 

  • Southeast Minnesota Water Analysis Laboratory

Last updated October 2024