Central Iowa Water Report yields public outcry - and EPA answers by delisting polluted rivers

Story and video from Iowa Environmental Council, August 2025

On July 1, 2025, the Harkin Institute and Polk County released the findings from the Central Iowa Source Water Resource Assessment (CISWRA) report titled Currents of Change. A month later, more than 1000 people gathered in Des Moines to hear the first presentation on the report.  The experts agree: Iowa’s waterways are impacted by agricultural pollution. You can read the entire report or view the executive summary to learn more. For additional highlights and takeaways, watch the full presentation and listen to episodes 3 and 4 of the Canary in a Cornfield podcast.

In addition to the presentation, Adam Shriver from the Harkin Institute was interviewed by the Environmental Working Group (EWG) to discuss the implications of the CISWRA report, "In Iowa, there's this big elephant in the room, which is that we're the number one leading state in confined animal feeding operations for hogs and for battery cage chickens." Shriver continues, "And also that we're the state that applies the most amount of synthetic fertilizers and chemical fertilizers."  Stay tuned to the Harkin Institute and IEC, who are planning more ways for people to stay involved in this conversation moving forward.

And then, EPA removes Iowa rivers from impaired waters list despite high nitrate levels.  The EPA is removing seven Iowa river segments, including water in the Des Moines and Raccoon rivers, from the impaired waters list.   Story coverage from WeAreIowa news (channel 5, Des Moines) is to the right.  

On July 11, 2025, EPA issued a letter to the Iowa Department of Natural Resources (DNR), rescinding its disapproval of the state's 2024 impaired waters list.  This unprecedented action means that major rivers in Iowa are not treated as exceeding the nitrate standard for purposes of the Clean Water Act.  ​

What is the Impaired Waters List? 
Under the Clean Water Act, every state must adopt water quality standards that define how it would like to use its waters and the pollution levels that would prevent those uses. When a water does not meet the standards and is too dirty for one of its intended uses, it is “impaired.” Section 303(d) of the Clean Water Act requires states to submit a list to EPA once every two years identifying impaired waters that need a plan to reduce pollution. EPA must approve or disapprove the list. Iowa DNR submitted its list in 2024 with 705 impairments. 

States must develop a water improvement plan for each waterbody on the impaired waters list and submit them for EPA approval. The plans must identify sources of pollution and the amount of pollution reduction needed to meet the water quality standard and protect the designated uses. The reductions are incorporated into permits for point sources, such as wastewater treatment facilities, but are not required for nonpoint sources, such as agriculture. 

"Efforts to de-list Iowa waterbodies for nitrate are clearly misguided. This action undermines the public process and the public trust in the agencies charged with keeping our water clean. The public already had opportunity to comment and overwhelmingly supported the listing that reflected real-life conditions in these rivers,” says Michael Schmidt, IEC General Counsel.  MARY ELLEN - I WILL TAKE OUT THIS PARAGRAPH AND REPLACE IT WITH A QUOTE FROM YOU, SHOULD YOU BE WILLING TO PROVIDE ONE.  IT WOULD GO INTO A PARAGRAPH SOMETHING LIKE FOLLOWS.... 

  What does this mean for these delisted rivers ?  LWV UMRR Chair, Mary Ellen Miller, says...>>>>>>>>>>