Marinette

## Summary

The municipal water system serving Marinette detected no PFAS compounds above the EPA Minimum Reporting Level in the most recent round of federal testing, a result that reflects the system's Lake Michigan source water rather than any treatment of contaminated groundwater. That clean result, however, exists alongside a well-documented regional contamination story: decades of aqueous film-forming foam (AFFF) testing at a fire-training facility operated by Tyco Fire Products (now part of Johnson Controls International) in the adjacent Town of Peshtigo released PFAS into local groundwater and surface water. That contamination has primarily affected private drinking water wells in unincorporated rural areas near the facility, not Marinette's municipal customers. Johnson Controls reached a settlement that continues to fund response actions for affected private well owners in the surrounding area, and remediation efforts remain ongoing.

## What the data shows

Marinette Waterworks (PWSID WI4380395), the sole public water system serving the city, was tested under the EPA's fifth Unregulated Contaminant Monitoring Rule (UCMR 5), which screens for 29 PFAS compounds. Across all samples collected, every one of those 29 compounds came back as a non-detect, meaning none were found at or above the EPA Minimum Reporting Level. No compound approached the federal limit. The system serves approximately 11,000 people and draws its supply from Lake Michigan.

## What residents should know

Customers of Marinette Waterworks can take some reassurance from these results, but the picture for the broader Marinette area is more complicated. Private well users in the surrounding rural areas, particularly those near the former Tyco fire-training site in the Town of Peshtigo, are not served by Marinette Waterworks and should not assume their water shares the municipal system's results. Residents on private wells who have not had their water tested should contact the Wisconsin Department of Natural Resources or their county health department for guidance on testing options. Anyone with questions about the municipal supply should contact Marinette Waterworks directly for the most current sampling data.