Corn drapes every field curve and rise in southeast Minnesota and runs up to the walls of a big hog containment operation. Credit: Keith Schneider, Circle of Blue

Responding to pervasive farm-related toxic water pollution, the U.S. Environmental Protection Agency has directed three state agencies to address the “imminent and substantial endangerment to the health” of thousands of southeast Minnesota residents exposed to high levels of nitrate contamination in their drinking water. 

In one of the strongest orders ever issued by the federal agency to limit farm pollution from livestock and crop production, the EPA directed three state agencies to collaborate on a plan of action to immediately reduce the risk of drinking nitrate-contaminated water. The EPA also called on Minnesota to more stringently regulate manure management at large livestock operations, a primary source of the contamination.  

The EPA’s demands for action on nitrate pollution came in a letter to the Minnesota Pollution Control Agency, the Minnesota Department of Health, and the Minnesota Department of Agriculture on Nov. 3. It responds to a petition filed last spring by the Minnesota Center for Environmental Advocacy (MCEA) and 10 other groups calling on the agency to investigate. The EPA’s response to the petition comes as federal and state authorities in Corn Belt states express much greater concern in addressing the threats from farm-related water pollution.  

“We know what causes this pollution. It’s time for Minnesota’s agricultural lobby and the Department of Agriculture to come to the table and agree to real solutions to eliminate this public health threat,” Leigh Currie, MCEA director of strategic litigation, said in a press release.

Concern across Corn Belt

Nitrate contamination risks extend well beyond Minnesota. In June, in a separate action, the EPA said it would formally assess the risk to human health from nitrates in drinking water. In Iowa, state Rep. Austin Baeth (D), pledged to hold hearings next year on the causes of cancer in a state with the worst nitrate contamination in water and second highest cancer incidence. In Nebraska, the University of Nebraska is investigating the links between nitrate contamination and startlingly high rates of pediatric cancer.

“The feds are interested in human health,” said Jeff Broberg, director of the Minnesota Well Owners Organization, an advocacy group. “That’s been the missing link in considering the hazards of nitrate pollution.”   

The EPA said its priorities in Minnesota included testing drinking water in the region, contacting individuals and families at risk, and providing alternate sources of clean drinking water “for as long as nitrate concentrations in the groundwater remain at or above” the federal drinking water limit of 10 parts per million. 

State data cited by the EPA show that nearly 400,000 people live in the area of southeast Minnesota and are affected by high nitrate concentrations from agriculture. Nearly 94,000 rely on private wells as their primary source of drinking water and nearly 9,300 people are “at risk of consuming water at or above the maximum contaminant level for nitrate”.

The EPA also called on Minnesota agencies to establish two new rules to limit nitrate pollution from large dairy, swine and cattle operations, and to enforce violations. 

  • The agency said it wants Minnesota to require livestock operatives to install monitoring wells around their feedlots and in the fields where nitrogen-rich manure is spread. 
  • The EPA wants the state to strengthen rules for when, where and how livestock operations spread manure and commercial fertilizer on their land to limit nitrate contamination. 
  • And “EPA expects Minnesota to hold sources of nitrate accountable using all available tools to reduce the amount of nitrate they release to groundwater.”

In response to queries, the Minnesota Pollution Control Agency issued a statement: “Minnesota is currently implementing long-term strategies to reduce nitrate groundwater from agricultural practices through fertilizer storage and management planning and improved application. While progress has been made, more work is required.”

Neither of the other two state agencies nor agriculture trade associations responded to requests for interviews. 

Nitrates form when nitrogen from commercial fertilizer and manure are exposed to oxygen. The three Minnesota agencies responsible for addressing water pollution have been aware for decades of nitrate contamination in the southeast region of the state. Crop and livestock production accounts for roughly 70% of the state’s nitrate pollution, according to the Minnesota Pollution Control Agency.

In Winona County, for instance, much of the groundwater in the porous limestone beneath the surface is contaminated with some of the nation’s highest levels of nitrates, according to state data.  

Nitrates are linked to a range of health problems, including heart and lung problems, and certain cancers. Nitrates are known to be particularly dangerous for babies. Health researchers in Iowa have found mounting evidence that drinking water with elevated levels of nitrate is linked to bladder and doubled the risk of ovarian cancer in women. 

Keith Schneider is senior editor and chief correspondent with Circle of Blue.

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