DNR: Ames drinking water has ‘forever chemicals’


By Jared Strong, Iowa Capital Dispatch

Statewide drinking water testing has revealed two more cities with detectable amounts of toxic chemicals that persist indefinitely in the environment, including Ames, the state’s ninth-most-populous city.

The Iowa Department of Natural Resources is sampling water in dozens of cities to gain a better understanding of the prevalence of perfluoroalkyl and polyfluoroalkyl substances — commonly known as PFAS or “forever chemicals.” They are synthetic chemicals used to make non-stick and stain-resistant products and firefighting foams, among others. Research shows they can cause cancers when ingested by people.


Newly released DNR data show small amounts of the chemicals are present in the treated drinking water that goes to homes and businesses in Ames in central Iowa and Rock Valley in far northwest Iowa. The testing has previously found the chemicals in West Des Moines water.

“We take this very serious, and we’re going to go above and beyond what we are required to do,” said Lyle Hammes, the water plant superintendent for Ames.

The current federal safety threshold for PFAS is 70 parts per trillion in drinking water, although the U.S. Environmental Protection Agency has indicated that might be too lenient. The chemicals tend to accumulate in people’s bodies, and most Americans are believed to have detectable amounts in their blood. The EPA is expected to revise its PFAS health advisory this year with a new safety threshold.

Ames’ treated drinking water had much smaller amounts than the federal standard, according to DNR sampling in December. Two prominent PFAS — perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) — were detected in concentrations of 3.1 and 6.5 parts per trillion. Because the chemicals were detected in the city’s finished water, the state wants Ames to test the water quarterly.


The DNR also sampled water from three Ames wells, all three of which had PFAS. One of the wells, located near Hilton Coliseum, was significantly higher than the rest at 12 and 26 parts per trillion for PFOA and PFOS.

Hammes said the DNR specifically targeted that well for sampling because its general location has been a site of firefighter training. Firefighting foams are a known source of groundwater contamination in the state, especially near certain airports.



There is another city well in the area that was not sampled, Hammes said. The city plans to more thoroughly test water at its 22 wells and treatment plant to understand the scope of its PFAS contamination.

Hammes said Ames learned of the test results about two weeks ago and is still discussing how it will inform local residents and other water customers. Ames’ population is about 66,000.

In Rock Valley, with a population of about 4,000, PFOS was found in concentrations of 2.1 per trillion in treated drinking water. The DNR sampled two of the city’s wells, and one had detectable amounts of PFOS at 3.6 parts per trillion.

Rock Valley city leaders did not respond to a request to comment for this article.

Fewer than half of the DNR’s expected tests of drinking water have been published on its PFAS sampling page. Roger Bruner, supervisor of the DNR’s water quality bureau, has said testing is still underway and results will be posted as the department receives them.

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