The Iowa Department of Natural Resources, which fought federal efforts to add segments of the Raccoon and Iowa rivers to its impaired waters list in 2024, now is including them.
The Iowa DNR said Tuesday, Feb. 17, that the Raccoon and Iowa rivers are among 574 segments of rivers, lakes, streams, reservoirs and wetlands it’s included on the state’s draft 2026 list of waters impaired because of factors that can include unsafe bacteria, advisories against fish consumption, harmful algal blooms and ― in the case of the two rivers ― high nitrate levels.
The DNR said it added the rivers to the list after assessing the segments with two years of new data. The 2026 assessment covers conditions from 2022 to 2024.
The 2024 assessment used data from 2020 to 2022.
Iowa and other states are required to assess the quality of their rivers, lakes and streams every two years to determine if they meet designated for uses for recreation, fishing and drinking water.
The Iowa DNR is also recommending that 83 waters be removed from the impaired waters list, which undergoes U.S. Environmental Protection Agency review. A segment can be delisted because an improvement plan is created, for example, or because corrective action has been taken after a spill, among other reasons.
The report showed Iowa had 33 fish kills over the two-year cycle, which included 15 due to fertilizer spills or animal waste releases.
During the Biden administration, the DNR battled EPA Region 7’s 2024 decision to add the Iowa and Raccoon segments, along with five others, to the list, saying the federal government made “several legal errors.”
The EPA, under President Donald Trump’s appointees, reversed that decision in July and delisted the seven segments, which also included the Cedar, Des Moines and South Skunk rivers. Two environmental groups have notified EPA Region 7 this month they plan to sue the agency for failing to finalize that decision as required under federal regulations, a necessary step before they can challenge it.
A state attorney told the Iowa Environmental Protection Commission on Tuesday that the environmental groups’ warning of their intent to sue doesn’t directly involve the Iowa DNR.
“We stand by our listing decisions, which is robustly supported by our methodology,” said Tamara McIntosh, Iowa DNR general counsel.
DNR Water Quality Monitoring & Assessment Supervisor Mark Moeller told the commission Tuesday that listing a waterway as impaired doesn’t mean it’s polluted.
“In reality, the impairment is a legal trigger and it ranges from slight to severe,” said Moeller.
The report doesn’t indicate the severity of an impairment, he said, comparing the rivers’ listing to a student missing one question out of 100 on a test and getting an ‘F’ instead of an ‘A-minus.’ “The only way you can get an ‘A’ is to get every answer right,” he said.
The state said the number of impairments has been relatively stable from 2014 to 2024.
In November 2024, the EPA told the DNR it had “partially approved and partially disapproved” the state’s impaired waters list, which included 577 segments of waterways with 746 impairments. This year’s segments have 751 impairments.
Moeller called the impaired waters list a “problem-identifying tool and a roadmap for restoration.”
The state said the Raccoon River segment previously has been included on impairment lists and has an improvement plan in place, but the Iowa River segment impairment is new. The river is a source of drinking water for Iowa City and the Raccoon River, along with the Des Moines, for the Des Moines metro.
Last summer, nitrate levels in the Raccoon and Des Moines rivers reached near-record highs, forcing Des Moines Water Works to run its costly-to-operate nitrate removal system for 112 days and ban lawn watering to maintain its treatment capacity. The water utility is again running its nitrate removal equipment, beginning Jan. 6.
Iowa City and other cities and towns across the state also struggled with high nitrate levels last summer and over the winter.
The state is accepting public comments on the proposed list over the next 30 days. The comment period will end on March 19.
Donnelle Eller covers agriculture, the environment and energy for the Register.
This article originally appeared on Des Moines Register: State changes course, adding Iowa, Raccoon rivers to impairment list
Reporting by Donnelle Eller, Des Moines Register / Des Moines Register
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