Environmental Groups Challenge EPA De-Listing of Nitrate Impairments in Iowa

Des Moines – The Iowa Environmental Council (IEC), Environmental Law & Policy Center (ELPC), and Food & Water Watch sent a letter to the Environmental Protection Agency (EPA) challenging the agency’s action to rescind its partial disapproval of Iowa’s 2024 Impaired Waters list under Clean Water Act section 303(d). 

EPA issued that partial disapproval on December 30, 2024, listing seven water segments in the state as impaired due to nitrate levels. IEC and ELPC commented in support of the proposed additions to the 2024 impaired waters list in order to limit nitrate contamination in drinking water sources. Drinking nitrate-contaminated water is linked to a host of negative health outcomes including birth defects and cancers.

On July 11, 2025, EPA took the highly unusual step of rescinding its partial disapproval, claiming that it was removing the newly listed impaired segments because it was “appropriate to allow EPA to evaluate additional information.” This unprecedented action means that major rivers in Iowa are not treated as exceeding the nitrate standard for purposes of the Clean Water Act. (Read more about the timeline, the Impaired Waters List, and nitrate impairments here.)

The public only discovered EPA’s action weeks after its decision. EPA and DNR did not provide notice to the public or opportunity for input.

“EPA’s action undermines the public process defined in federal regulations and limits public transparency,” said Michael Schmidt, General Counsel for IEC. “No law says that EPA can change its mind after it made a final decision the way it did in this case, especially when it is weakening protections for the public. The path to this decision lacks transparency and is based on outdated and incomplete information.”

EPA rescinded its December listing of the waters after DNR explained its position in a phone call and provided additional information. IEC submitted a records request that showed the only written communication was an email sending decades-old documents that had already been submitted to EPA, along with EPA's own decades-old approval letter. The DNR email did not include the DNR position cited in EPA’s letter.

"EPA rolling back water quality protections based on ‘back room’ conversations is not how agencies should operate,” said Josh Mandelbaum, Senior Attorney at ELPC. “While Iowa is in the midst of ongoing and serious water quality problems, there is no justification for EPA to flip-flop because of old documents it already had, especially its own letter from 2002.”

Food & Water Watch Staff Attorney Dani Replogle said: “The data is clearer than ever that Iowa waterways are overwhelmed with persistent, toxic nitrate contamination. Iowans need more clean water protections — not less. EPA’s baseless decision to turn its back on central Iowa’s water crisis without even providing an opportunity for public input does not inspire confidence in the federal agency meant to safeguard clean water and protect our health. Iowans demand and deserve better.”

The environmental groups’ letter highlights that the new direction will increase regulatory costs for downstream water users, including Iowa’s most populous metropolitan areas. DNR and EPA seek to treat the drinking water standard for nitrate as a long-term, chronic standard – despite the short-term effects such as blue baby syndrome.

“While this path may seem complex, the issue is simple: EPA is not doing the important work of protecting public health. Claiming that our waterways meet drinking water standards when EPA has found those same nitrate levels could cause blue baby syndrome is unjustified and dangerous,” said Colleen Fowle, Water Program Director for IEC. “Removing the impairment at the same time Central Iowa had to implement unprecedented water use restrictions made no sense. EPA’s action fails to put the onus on the polluters to adopt practices that will actually fix the problem.” 

The letter sent by the environmental groups states that because EPA has reopened the process to consider additional information, it should consider public input. The letter includes additional information about the application of the drinking water standard on a short-term basis. The groups explain that the documents adopting the water quality standard for drinking water do not justify treating nitrate as a chronic pollutant.

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The Iowa Environmental Council (IEC) is an alliance of diverse organizations and individuals working together to protect Iowa's natural environment. Founded in 1995, it is the largest and most comprehensive environmental coalition in the state. Through education, advocacy and coalition building, the Council raises awareness, generates action and creates large-scale change that makes Iowa a better place to live, work and explore. Learn more at www.iaenvironment.org. 

The Environmental Law & Policy Center is the Midwest’s premier environmental legal advocacy organization. We use the power of the law and strategic advocacy campaigns to create climate change solutions, advance clean energy, protect public health, and preserve the Midwest’s wild and natural places.

Food & Water Watch is a national nonprofit that mobilizes people to build political power to move bold and uncompromised solutions to the most pressing food, water and climate problems of our time. We work to protect people’s health, communities and democracy from the growing destructive power of the most powerful economic interests. For more information, please visit foodandwaterwatch.org.