PFAS and other compounds detected in Milwaukee Estuary

PFAS compounds (per- and polyfluoroalkyl substances) have been detected in the Milwaukee Estuary, which was designated as an Area Of Concern (AOC) by the U.S./Canada International Joint Commission in 1987. Samples were taken from the area in November 2019, which recently indicated the presence of the forever chemicals to the Department of Natural Resources (DNR).

PFAS chemicals are part of a group of possibly thousands of man-made compounds which have a long and storied history in American industry. From firefighting foam to Teflon pans, non-stick coatings to even clothing, PFAS chemicals have been used in countless products over decades.

In that time, the compounds have contaminated a variety of environments including but not limited to ground water, waterways, and landfills. High levels of exposure to the chemicals have been linked to a variety of health concerns in humans and other animals, including cancers, low fertility and birth defects. The contamination of humans and farm animals in a rural American community became the subject of the 2019 movie Dark Waters. The film focused on PFOA (Perfluorooctanoate) and PFOS (Perflurooctane sulfonate) compounds, which are related to PFAS.

Identifying and cleaning up contaminated sites across Wisconsin has been a growing concern for state officials. Results from the Milwaukee Estuary AOC found PFAS compounds in sediment, and every surface water sample. Another compound, PFBA, which is considered less toxic than some of its counterparts, was found in all of the surface water samples as well.

Some thirteen locations in the Milwaukee, Menomonee and Kinnickinnic Rivers, along with the inner and outer harbors, and one location in Lake Michigan, were sampled for 35 different PFAS compounds. The highest levels of PFAS were found in samples taken furthest upstream from Lake Michigan.

In the Kinnickinnic River, samples of PFHxS (Perflurohexanesulfonate) were found at 44.4 parts per trillion (ppt) in the surface water. PFOS chemicals were found at 9.1 parts per billion (ppb) within sediment in the region. However, samples taken closest to the drinking water source flowing through the Linnwood and Howard Avenue Water Treatment Plants, PFOA and PFOS were detected at 1 ppt. PFAS levels found in the Milwaukee Esturary were generally lower than those found in Madison’s Starkweather Creek, though higher than recent samples from the Wisconsin, Mississippi and Menomonee Rivers.

While clean-up operations are organized, residents near any of these areas are advised to avoid eating fish from these waters. Especially for Starkweather Creek and Lake Monona, but also in the areas of the Milwaukee Estuary and nearby rivers. That being said, the compounds can also be found in animals which drink from these waters, including deer and livestock. PFAS and their innumerable cousin-compounds are highly dynamic in how they move through the environment, and do not degrade.

PFAS clean up largely revolves around the DNR working with the parties responsible for individual contamination sites, essentially getting the to clean up their own mess. The spread of COVID-19, however, has created new challenges and impediments to clean-up operations. The DNR is currently evaluating a request to halt sampling from Johnson Controls which, along with its subsidiary Tyco Fire Products, is responsible for several sites. In a Zoom meeting open to the public on April 15, DNR remediation and redevelopment program director Christine Haag said the request is still being evaluated.