Wausau, WI
Home MenuPFAS Information
History of PFAS in Wausau
In 2019, Wausau Water Works conducted voluntary testing of all municipal drinking water supply wells (raw water) for per- and polyfluoroalkyl substances (PFAS.) Testing was completed to identify possible future contaminants the City may have to manage with the new treatment facility. Test results for PFOA/PFOS ranged from 8.65 to 15.1 ppt per compound, or 18 to 27.5 ppt combined. At this time there were no drinking water standards for PFAS at the federal or state levels. The United States Environmental Protection Agency had an established Health Advisory of 70 ppt.
In the winter of 2020, the Wisconsin Department of Health Services (WDHS) made recommendations to the Wisconsin Department of Natural Resources (WDNR) for establishing a drinking water standard for PFAS. In 2021 the WDNR began work of formulating a PFAS drinking water standard to present to the Wisconsin Natural Resources Board (NRB). The NRB met in Feb 2022 to consider the WDNR PFAS drinking water standard of 20 ppt and the NRB approved a drinking water standard of 70 ppt for combined PFOA/PFOS.
In January 2022, the city conducted additional voluntary testing on wells and finished/treated water and the test results ranged from 8.7 to 23 ppt per compound, or 23.8 to 35.3 ppt combined PFOA/PFOS. Even though there was no approved drinking water standard for PFAS, the City of Wausau adopted a policy to maintain PFAS levels below 20 ppt as recommended by WDHS. It was unclear what level of PFAS was safe, but the City took the most conservative possible route to reduce PFAS compounds in drinking water.
Residents were advised to use bottled water for drinking, and the city issued special water filter pitchers. Wausau was in the process of building a new water treatment plant to improve overall water quality and prepare for future regulations. The new water treatment facility includes an anion exchange treatment system that is primarily used for total organic carbon (TOC) removal and it also reduces PFAS during the treatment process to below 20 ppt for PFOA/PFOS. The new water treatment plant went online in December 2022. This would be the first of a two part process to treat the raw water and remove the PFAS.
The City has also begun the construction of a granular activated carbon (GAC) treatment system as a long-term solution for removing known PFAS compounds to non-detectable levels. This treatment process is scheduled to begin operations in November 2024.
In June of 2023, the City of Wausau signed on to a multi-district litigation over the contamination of drinking water resulting from widespread use of aqueous film-forming foam. The proposed class settlement amount is in the billions of dollars and is intended to cover the costs of water treatment needed to eliminate PFAS from public water supplies. This settlement still needs to be approved by the court, and then steps will be taken to file the claim.