New federal rule would require several Iowa cities to fix ‘forever chemical’ contamination
The U.S. Environmental Protection Agency will require all water utilities to test their treated drinking water for toxic “forever chemicals” and — if they are detected in certain concentrations that have been found in Iowa cities — find a way to remove them or obtain a different water source.
Those requirements are part of a proposed rule the EPA announced on Tuesday. The agency is seeking feedback and is set to hold a public hearing in April, with the expectation that the rule will be finalized by the end of this year.
Perfluoroalkyl and polyfluoroalkyl substances — also known as PFAS or “forever chemicals” because they persist indefinitely in the environment — have been discovered in the treated drinking water of more than a dozen communities in Iowa. They have been used to produce common non-stick and stain-resistant items, firefighting foams and other products for decades and are linked to cancers and other health ailments.
The Iowa Department of Natural Resources has sampled 126 water supplies in the state since 2021 and is poised to start another phase of testing that will sample nearly 40 more. The proposed federal rule will lead to the sampling of about 800 more water supplies in Iowa, said Corey McCoid, supervisor of the DNR’s Water Supply Operations.
“The work that we’ve been doing for the last couple of years, that’s given us a good idea as a state for what to expect,” he said.
The DNR has focused its testing in areas of the state with the highest likelihood of contamination, but there is potential that widespread testing will reveal unanticipated contaminations.
When the recent DNR testing program began, federal officials had a health advisory that said water should not contain the two most-studied PFAS in concentrations that exceed 70 parts per trillion. It was an unenforceable guideline, and none of Iowa’s tested water exceeded that number.
But in June 2022, the EPA cited a growing amount of evidence that any consumption of the chemicals was unhealthy. It reduced the safety threshold to as low as 0.004 parts per trillion, which is too small to detect by current technology. The DNR tests can detect about 2 parts per trillion.
Citing the testing limitations, the EPA is proposing an enforceable maximum contaminant level of 4 parts per trillion for the two common PFAS — known as PFOA and PFOS. The new rule would also regulate the allowable concentrations of four other related chemicals, which will be measured as a group. There are thousands of PFAS variations.
Several cities that had contaminated water have been able to reduce or eliminate detectable PFAS in their treated drinking water by shutting down contaminated wells.
But some communities don’t have that option and will likely need to drill deeper wells or install treatment equipment to remove PFAS, McCoid said. Those might include Dubuque, Muscatine, Tama, Sioux City and a mobile home park near Muscatine.
Iowa is expected to receive a total of more than $100 million of federal assistance in the next five years to help pay for those projects.
Testing in cities that draw water from the Mississippi River have intermittently revealed contaminations that near the new proposed enforceable threshold. To determine whether mitigation is necessary, the EPA will use an average of quarterly tests. So it’s possible that the drinking water will have a higher-than-allowed PFAS concentration for part of the year without triggering a requirement to remove the contamination.
Even in cities where the contamination problems have been fixed by idling wells, there might still be a need for federal assistance. Central City shut off one of its two wells after tests showed a combined PFAS concentration of 61 parts per trillion. There is now no detectable PFAS in Central City water, said Trevyn Cunningham, the city’s public works director.
But the city might lack the capacity to meet a spike in water demand — if firefighters must extinguish a large fire, for example — and is planning to drill a new well in an uncontaminated area. Cunningham said that might cost up to $1.5 million, and the city hopes the federal assistance covers the entire cost.
Under the proposed federal rule, water utilities that serve 10,000 people or more are required to initially test their treated water quarterly. Smaller utilities must test twice each year. Depending on the test results, the sampling frequency can be reduced.
The rule would also require tests of independent water systems that serve more than 25 people. That can include factories, hospitals and other facilities that do not connect to municipal water supplies.
Camanche, in far eastern Iowa, also has contamination that exceeds the proposed safety thresholds, but 3M has agreed to pay for two new wells for the city. The company’s nearby plant has produced PFAS for decades and is believed to have contaminated the area.