LINCOLN, Neb. (DTN) -- A coalition of more than 80 environmental groups asked the Trump administration to reduce nitrate pollution in lakes, rivers and groundwater, following the release of a report in March that found links to cancer from rising nitrate levels in Iowa's waters.

In April 2024, Iowa environmental groups filed an emergency petition with the U.S. Environmental Protection Agency under the Safe Drinking Water Act focused on the Karst region in northeast Iowa. That petition asked EPA to investigate why state regulations have not prevented the expansion of ag practices in contaminated areas.

The groups asked the EPA as well as the U.S. Department of Health and Human Services to respond to that petition, and to declare a public health emergency to identify and eliminate nitrate pollution sources and to provide funding to communities to reduce nitrate levels in drinking water.

"It is imperative that EPA and HHS act now to address this public health emergency in Iowa and across the country," the letter said.

The letter is signed by the Center for Biological Diversity, Center for Food Safety, Food and Water Watch, Union of Concerned Scientists, Environmental Law and Policy Center, Friends of the Earth, Izaak Walton League of America, Waterkeeper Alliance, among many others.

In March 2026, the Iowa Environmental Council and the Harkin Institute for Public Policy and Citizen Engagement, published a report outlining environmental risk factors and Iowa's cancer crisis.

The groups signing the letter to EPA Administrator Lee Zeldin and HHS Secretary Robert Kennedy on Tuesday pointed the finger at agriculture as the problem.

"The IEC-Harkin Report is clear that intensive agricultural practices are the dominant source of this nitrate pollution in Iowa's waters," the groups said in the letter.

"In 2024 alone, 11.9 billion pounds of synthetic fertilizer, a major source of nitrate pollution, were purchased in Iowa, much of which ran off the fields where it was applied or leached into waterways. Iowa is also home to more concentrated animal feeding operations than any state in the country, and these operations produce large volumes of manure that contribute to nitrate runoff. Further, Iowa has lost over 97% of its wetlands that, had they not been destroyed, could have helped filter nitrates and other contaminants from agricultural sources."

The groups told HHS and EPA that nitrate exposure has been linked to cancers, birth defects as well as many other health conditions. Despite that, they said in the letter EPA has not responded to the petition, calling it an "egregious dereliction of duty" considering "mounting evidence" of a public health crisis.

The letter said action is needed because the science on nitrates in drinking water has evolved.

"The science is now clear that nitrates in drinking water well below the current maximum contaminant level (MCL) of 10 mg/L, presents health risks," the letter said.

"Studies indicate increased risk of colorectal cancer, ovarian cancer, bladder cancer, kidney cancer, thyroid and prostate cancer associated with consuming water with nitrate concentrations over 5 mg/L, 3 mg/L, or as low as 2 mg/L -- five times less than the current MCL."

In May 2023, the Iowa Department of Agriculture and Land Stewardship released an update to its online dashboard tracking the effectiveness of the state's 2013 voluntary nutrients reduction strategy.

The state reported the amount of cover crops planted in Iowa grew from about 10,000 acres in 2013 to over 2.8 million acres in 2021. Farmers' use of no-till crop acres grew from 6.2 million acres in 2010 to 9.5 million acres in 2021.

State data, however, continues to show little change in nitrate levels in water.

Read more on DTN:

"Iowa Runoff Continues Despite Strategy," https://www.dtnpf.com/…

Todd Neeley can be reached at todd.neeley@dtn.com

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