Are ‘forever chemicals’ in your drinking water?

The state has created an interactive, online map for Iowans to track whether their drinking water has detectable amounts of cancer-causing chemicals that persist in the environment indefinitely.

The map reflects early testing by the Iowa Department of Natural Resources for perfluoroalkyl and polyfluoroalkyl substances — commonly referred to as PFAS or “forever chemicals.” They are synthetic chemicals that have been used to make nonstick cookware, stain-resistant clothes and furniture and firefighting foam, among other products.

Research has increasingly shown that they pose public health risks, and the U.S. Environmental Protection Agency is in the process of revising its guidance for drinking water contamination. Currently, it advises water utilities that 70 parts per trillion is safe for consumption, but the agency has insinuated that number should be smaller.

The DNR said last year it would test water sources and treated water in at least 59 cities for PFAS. The DNR’s map, which was posted last week, contains the results from about a quarter of them.

“All the sampling has not been completed and may take a month or more to complete,” said Roger Bruner, supervisor of the DNR’s water quality bureau. “We put up the data on the site as we get results.”

The map indicates where two of the most-studied PFAS have been detected in drinking water. So far, West Des Moines is the only city with that distinction, and its water utility shut down one of its three wells that were found to be contaminated.

Iowa City’s Sand Pit pond, located north of U.S. Interstate 80 along the Iowa River, has small amounts of PFAS. (Graphic courtesy of Iowa City.) 

However, the map doesn’t display where PFAS were found in drinking water sources, such as in Iowa City. The city is marked with a green dot to show no PFAS were detected in the treated drinking water, but residents must navigate into a pages-long chart to discover that one of its drinking water sources had perfluorooctane sulfonic acid, one of the two main PFAS.

The chemical was found in concentrations of 2.4 parts per trillion in the Iowa City Sand Pit pond, which is an occasional source of drinking water for the area and can account for up to 10% of the city’s water supply.

At the time of the DNR water sampling, the city was not drawing water from the Sand Pit, said Jonathan Durst, water superintendent for Iowa City. It’s unclear from the DNR testing how the Sand Pit water might affect the presence of PFAS in the finished drinking water.

Full test results from the DNR’s sampling is available online. This snippet, which shows the presence of PFAS in the Iowa City Sand Pit (red oval added for emphasis), is part of an 11-page report. 

“We plan to continue testing on our own to better understand all of our sources and the impact of each treatment process on PFAS,” Durst said.

Bruner said the DNR map highlights the status of finished drinking water that goes out to customers, but the full test results of water sources are also available “to be as transparent as possible.”

“The department’s surveillance project for PFAS is designed to give a snapshot of occurrence(s) of PFAS compounds in finished and raw water at public water supplies to assess the magnitude of the issue in Iowa,” he said. “This information will be used to decide future work in a data-driven approach.”

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