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Home > Protecting Our Lands & Waters > Clean Water Fund > Groundwater & Drinking Water Protection > Characterizing Nitrates in Private Drinking Water Wells

Characterizing Nitrates in Private Drinking Water Wells




Residents in certain areas of the state are invited to participate in the MDA's private well network. Participation is voluntary and easy. Participants collect and mail water samples from their drinking wells using the provided test kits and prepaid postage.

The data collected is used to determine the trend of nitrate levels in regional groundwater over time. To the greatest extent possible the same households are tested each year. This allows us to determine if nitrate levels are increasing, decreasing or remaining the same.

The MDA currently works with two networks in the state. The groundwater in each area is vulnerable to nitrate contamination. Nitrate can move easily through the soils and geology of these regions. Sandy soils in the central region of Minnesota and sinkholes and underground caves in southeast Minnesota (karst geology).

  1. Central Sands Region
  2. Southeast Karst Region
    2017 Results- Southeast Minnesota Volunteer Nitrate Monitoring Network (PDF: 617 KB / 2 pages)
    Additional Reports for this project can be found on the Minnesota Department of Health's website.

How does it work?

The study is done in partnership with the counties of the region. Large efforts are made to ensure that participating households are randomly selected and evenly distributed across the region. Once selected, homeowners are invited to participate. Homeowners are asked to share information about their well's construction, depth, age and other descriptive features. Water samples and the well survey information are sent back to the lab in a prepaid return envelope.

Why is this program focused on Nitrates?

Nitrate is a water soluble molecule that is made up of nitrogen and oxygen. It is naturally occurring in the environment; however at elevated levels it can have negative effects on human health. According to a 2007 Minnesota Pollution Control report, nitrate is one of most common contaminants in Minnesota's groundwater, and in some areas of the state a significant number of wells have high nitrate levels (Minnesota's Ground Water Condition: A Statewide View, MPCA 2007). The U.S. Environmental Protection Agency (USEPA) has established a drinking water Maximum Contaminant Level (MCL) of 10 mg/L for nitrate-nitrogen (U.S. EPA, 2009).

Although nitrate occurs naturally, it can also originate from man-made sources such as fertilizer, animal manure and human waste.

Regions of Minnesota most vulnerable to nitrate contamination are central and southeastern Minnesota. Central Minnesota counties are vulnerable because of widespread sandy soil and regions of southeast Minnesota are vulnerable because of shallow bedrock, sinkholes and underground caves (referred to as karst geology), which lead to exchanges between surface and ground water resources.  


Nitrate Water Testing Clinics

Between 1993 and 2006, the MDA operated "walk in" style water testing clinics with the goal of increasing public awareness about nitrates in rural drinking and livestock water supplies. The clinics offered free nitrate analysis and provided immediate results to homeowners.

This accurate, yet inexpensive water testing procedure has provided nitrate analysis and educational outreach to over 50,000 well owners.

The MDA has trained many local partners to operate nitrate testing clinics. Equipment and training are available for any community that would like to offer testing services. This procedure is adaptable for county fairs, field day events, public school programs, and "stand alone" events.

In 2011, the MDA helped 40 Local Government Units host nitrate testing clinics. A total of 2,100 water samples were tested. This information will be updated soon to reflect plans for the summer of 2013. Although MDA does not provide staff for the events, testing equipment is available.


County Partners: Becker, Benton, Cass, Crow, Douglas, Hubbard, Kandiyohi, Morrison, Otter Tail, Pope, Sherburne, Stearns, Todd, Wadena
**Wadena County Soil and Water Conservation District is the lead local project coordinator.

Additional Partners: Minnesota Center for Survey Research, RMB Environmental Laboratories, Inc.

 MDA Contacts

Kimberly Kaiser
Hydrologist 3
Kimberly.Kaiser@state.mn.us ~ 651-201-6280

Bruce Montgomery
Fertilizer Section Manager
Bruce.Montgomery@state.mn.us ~ 651-201-6178