Pointing to fish kills and growing nitrate contamination in Southeast Minnesota wells, a coalition of Minnesota environmental organizations last week petitioned the federal government to step in. State agencies aren’t doing enough to protect drinking water from agricultural pollution, they argued, asking the U.S. Environmental Protection Agency (EPA) to use emergency powers to take immediate action, including passing a moratorium on large feedlots and requiring polluters to provide free drinking water to affected communities.

The St. Paul-based Minnesota Center for Environmental Advocacy (MCEA) spearheaded the petition, and 10 other groups signed on, including Minnesota Trout Unlimited, the Minnesota Well Owners Organization (MNWOO), the Izaak Walton League, and the Land Stewardship Project (LSP).

“The persistent contamination of drinking water by nitrate in the karst region shows that Minnesota is not living up to its responsibility to protect public health,” MCEA’s Water Program Director Carly Griffith said in a statement.“No resident of our state should have to worry about what's in their water.”

“We need help,” MNWOO Director and Elba-based professional geologist Jeff Broberg said. “Despite a clear understanding of our groundwater sensitivity and the risk factors that have led to widespread nitrate contamination in the karst, our drinking water quality keeps getting worse.”

Nitrate contamination of groundwater is a longstanding issue in Southeast Minnesota. It’s caused by an excess of the nutrient nitrogen found in fertilizer, manure, and human waste. The Driftless Region is especially vulnerable due to its karst geology, where surface water and pollutants can easily reach drinking water aquifers through sinkholes and porous bedrock.

A 2017 Minnesota Department of Agriculture study of 940 Winona County wells found 19% exceeded the federal health standard for nitrate contamination (10 mg/l). In Utica Township near Lewiston, over 46% of tested wells exceed the limit, and in Fremont Township, the figure was nearly 55%.

In infants, consuming high levels of nitrates can inhibit the body’s ability to deliver oxygen and cause the dangerous blue baby syndrome. In adults, nitrates have been linked to higher risks for a variety of health problems including heart disease and other cardiovascular disorders, lung disease, and certain cancers, according to the Minnesota Department of Health.

According to the Minnesota Pollution Control Agency (MPCA), 70% of the nitrates in Minnesota waters come from agriculture, with sewer plants, septic systems, and urban runoff accounting for a fraction of the problem.

The city of Lewiston previously spent $900,000 to drill a deeper well to avoid high nitrate levels in its public water supply, and Utica is facing a similar problem now. Private well owners with high nitrate levels may resort to bottled water or expensive reverse osmosis systems.

The MCEA petition contends that all of this endangers the health of Southeast Minnesota residents and that state officials have failed in their duty under the federal Safe Drinking Water Act to protect residents’ health. 

In a statement, MPCA Communications Manager Michael Rafferty highlighted the work his and other state agencies are doing. “… Minnesota is implementing one of the first groundwater protection rules in the country designed to reduce nitrate in groundwater from agricultural practices. Minnesota also developed a nitrogen fertilizer management plan to reduce nitrate levels in vulnerable groundwater areas and promotes fertilizer and manure best practices,” he wrote. “While progress has been made, more work is required by state agencies, local governments, industry, farmers, and homeowners to protect our waters, especially as we continue to adapt to our changing climate.”

Despite that work to incentivize pollution-reducing agricultural practices and new state regulations on buffer strips and fertilizer, nitrate levels are getting worse, MCEA’s petition argues.

An MPCA report on private wells in Southeast Minnesota found “no statistically significant trend” in nitrates levels from 2008 through 2015. However, over a longer timescale, nitrate pollution has been rising. The petition cites a 2020 MPCA report that found nitrate levels in surface water statewide “have generally been increasing” in recent decades. In a 2019 presentation, Tony Runkel of the Minnesota Geological Survey pointed to a consistent trend of increasing nitrate levels in deep wells from 1975 to 2019.

The state’s marquee fertilizer regulation — the Groundwater Protection Rule — was only implemented in 2019, said Warren Formo, the executive director of the Minnesota Agriculture Water Resource Center, which represents agriculture organizations in addressing water quality issues. “We believe we need to give a little bit more time to see how much of a difference it can make,” he stated.

Formo added that complicating the issue of assessing how trends in agricultural practices are affecting groundwater is the issue of lag time, or how long it takes a surface pollutant to reach a given aquifer. According to the MPCA, the lag time at a given location can range from hours to decades. “It may take years before we see a correlation between what’s happening on the farm and what’s happening down below,” Formo said.

The petition calls for a prohibition on new confined animal feeding operations (CAFOs), or feedlots with over 1,000 animal units (714 dairy cows). It points to seepage from manure storage lagoons and late-season manure applications as major culprits in nitrate pollution, while also citing evidence that row cropping and the use of synthetic nitrogen fertilizer are significant contributors. Asked if the call for a moratorium singles out animal agriculture over crop farming, Griffith said both are serious issues but there isn’t the same permitting authority for the government to control crop farming and fertilizers as exists for feedlots.

LSP Policy Organizer Sean Carroll said in an interview, “Unfortunately, the MPCA has not done enough to stop big ag and the factory farming industry and the polluters from their practices that threaten our water … We need government policy to support the small and mid-sized farmers that care about protecting our water.” 

Asked if only large farms were contributing to the problem, Carroll said, “We need rules that farms of all sizes are going to follow, and pollution does probably come from farms of all different sizes.” However, current policies make it too easy for large industries to pass on the costs of their pollution to the public and to well owners, he added.

“Often the way the families can stay in business is to grow their business and have more animals,” Formo said. “I think it would be unfortunate if a farm needed to grow in order to pass things on to the future generation … and the only reason they couldn’t exist is because of a blanket ban.” He added, “We don’t see stewardship and conservation being size specific. It’s important for farms of all sizes to do the right thing. So we would focus on that more than size thresholds.”

The petition calls for the EPA to investigate the specific sources of Southeast Minnesota’s nitrate pollution and hold polluters accountable.

While the petitioners want more aggressive and immediate action, they shared some agreement with ag groups and state officials on potential long-term solutions. Cover crops and other best management practices are part of the solution, Griffith said, and she said the petition calls on the state to more widely broadcast tools such as the Runoff Risk Advisory Forecast, which helps farmers decide when it’s safe time to apply manure or fertilizer.

What will the EPA do? Griffith said the agency did take action in response to a similar petition to address lead pollution in Flint, Mich., and in a more parallel case, to address nitrates in Washington state’s Lower Yakima Valley. Conversely, the EPA declined to intervene following a petition regarding nitrates in Wisconsin, she noted. “We have examples that go in both directions,” Griffith said.

An EPA spokeswoman did not respond to specific questions but said in a statement, “EPA is currently reviewing the petition and will be reaching out to state and local agencies, as well as the petitioners, as we evaluate necessary next steps.”

In the meantime, Carroll said, people can learn more about the issue and what they can do to protect water quality at an upcoming presentation, “A Resource in Crisis,” at 6 p.m. on May 22 at the Lewiston Community Center.