EPA says Minnesota needs to take more action on nitrates in drinking water

Minnesota state agencies aren’t doing enough to prevent nitrates — a toxic byproduct of fertilizers and livestock manure — from entering drinking water in the southeast part of the state, according to the U.S. Environmental Protection Agency. 

The EPA notified the Minnesota Department of Agriculture, the Minnesota Pollution Control Agency and the Minnesota Department of Health last week that Minnesota isn’t effectively identifying, notifying and assisting people in southeast Minnesota who have high levels of nitrate in their drinking water. 

Southeast Minnesota is dominated by karst terrain, meaning water easily moves between the surface and underground, carrying with it runoff from the many livestock operations and crop fields in the region.

A more rigorous regulatory regime will face a key political obstacle: The powerful farm lobby, which is influential in both parties and has effectively resisted stricter limits on fertilizer pollution. 

The EPA may not give Minnesota much choice, however. The agency can take emergency or enforcement action if the state doesn’t hold polluters — in this case, farmers — accountable for the nitrates in Minnesota’s water. 

In a joint statement, the three state agencies named in the EPA letter said they would respond to the letter within 30 days. 

“Minnesota is currently implementing long-term strategies to reduce nitrate groundwater from agricultural practices through fertilizer storage and management planning and improved application,” the statement reads. “While progress has been made, more work is required by state agencies, local governments, and industry partners to reduce nitrate levels in our lakes, streams, and groundwater to protect drinking water for all Minnesotans.”

Drinking water with high levels of nitrate can cause methemoglobinemia or “blue baby syndrome,” a potentially life-threatening condition affecting the blood’s ability to carry oxygen throughout the body. Pregnant women and infants are particularly vulnerable to the effects of nitrates. Nitrates have also been linked to thyroid disease and certain cancers.

Public water systems monitor nitrate levels and take action when nitrates cross EPA limits, but the thousands of private well owners in the area are much less likely to know if their water is toxic. Even if a well owner tests their water quality, the few treatment options available for nitrates can be expensive.

The state agencies must identify every residence with a private well in the region, test their drinking water when requested and provide alternative water sources to those with high nitrates, the EPA said. 

Minnesota has made a number of efforts to curb the impact of nitrate pollution. It offered free testing to hundreds of townships from 2013 to 2019. The state is also implementing a Groundwater Protection Rule and has made state funds available to well owners to cover the costs of addressing nitrate pollution.

But the EPA is clear in its letter that “there is an evident need for further actions to safeguard public health.”

Minnesota Farm Bureau president Dan Glessing said the letter is “concerning” because state agencies are already taking action on nitrates.

“These nutrient reduction strategies take time to work, so we’re going to need to continue to monitor and go from there — and continue to examine sources that might not be agriculture-related,” Glessing said.

The letter also suggests Minnesota make changes to its permit system for large livestock facilities — legally referred to as concentrated animal feeding operations, or CAFOs — by adding a monitoring requirement for the manure and wastewater stored on site, and also for the runoff that occurs when the waste is used as fertilizer on crop fields. 

Glessing said the existing permit process, which requires CAFO owners to submit forms called “nutrient management plans” to the state, is sufficient for understanding the amount of nitrogen applied to a field and that additional monitoring is not needed.

The EPA investigated Minnesota’s handling of nitrate pollution in the Karst region at the request of a coalition of environmental groups.