‘Forever chemicals’ again detected in Mississippi River towns’ water

The treated drinking water of Burlington and Davenport are again contaminated by cancer-causing chemicals that persist indefinitely in the environment, according to quarterly tests of the water.

Those cities draw most of their water from the Mississippi River. In January, state tests revealed the river was contaminated by perfluoroalkyl and polyfluoroalkyl substances — commonly known as PFAS or “forever chemicals.”

But tests of the water in June found no contamination. The Iowa American Water Company, which supplies water for Davenport, has been sampling the river water since 2017, and the results have varied. Sometimes there is PFAS; sometimes there is not. There has been no decipherable pattern, the company has said.

The precise source of contamination is unclear, but there are known contaminated sites upstream operated by 3M, a major manufacturer of the chemicals.

The Iowa Department of Natural Resources has been sampling water since last year to determine the prevalence of PFAS in community water supplies. It has found them in more than a dozen.

This year, the U.S. Environmental Protection Agency lowered its safety thresholds for the two most-studied PFAS — which say that even miniscule amounts of the chemicals can be hazardous — and set new health advisories for others.

Some cities have stopped using contaminated wells to cut the PFAS in their treated water. West Des Moines was able to reduce its contamination to undetectable levels. Burlington and Davenport are at the whim of the Mississippi River. Davenport draws all of its water from the river. For Burlington, it represents about 85% of its total water supply.

Keokuk, which is downstream of those cities, also gets its water from the river. Its water had the chemicals in January, but a test in July did not detect the two prominent PFAS. The Burlington and Davenport tests that did detect the PFAS were in August, according to DNR records.

The water supplies with the worst contaminations include Central City in northeast Iowa and the Kammerer Mobile Home Park near Muscatine. Kammerer had about 8,000 times the safe amount of one of the PFAS in June. Central City had about 2,200 times the safe amount of another.