The search for a source of PFAS contamination spreading in the Huron River across five Southeast Michigan counties points to Wixom, where city officials told the state in June that its wastewater treatment plant has been sending contaminated water into a tributary.
The discovery comes as the state seeks tests from 95 municipal wastewater treatment plants with significant industrial processing.
It also comes as the state investigates PFAS contamination across the five-county Huron River Watershed that escalated Friday into a widespread "do not eat" fish advisory and signaled heightened concern about the chemical levels in southeast Michigan.
According to a letter sent Aug. 6 from the Michigan Department of Environmental Quality to the operator in charge of the Wixom wastewater treatment plant, PFOS at 290 parts per trillion (ppt) was measured in water discharged into Norton Creek in southwest Oakland County.
Test results sent to the city show that one of two Adept Plastic Finishing Inc. factories in Wixom sent high levels of the contaminant into the wastewater treatment plant.
Documents of water testing at Adept’s Plant 4 show a PFOS reading of 28,000 during a mid-May test.
Adept received the results on June 19.
The city notified the MDEQ of those results on June 27, according to documents.
The city must test its effluent monthly, according to the letter from the DEQ.
Dean said the state has not yet identified the boundaries for the contamination.