WYOMING, Mich. (WOOD) — The state says it will cost millions to get rid of the PFAS-based firefighting foam that is being stored in fire departments across Michigan.

It’s still not clear how that would happen, or when.

They could incinerate it, or even solidify it by mixing it with concrete before dumping it in hazardous waste landfills.

“It will not be a cheap solution to get rid of this AFFF foam,” State Fire Marshal Kevin Sehlmeyer said Thursday during a meeting of West Michigan fire chiefs.

A survey of fire departments across the state has found more than half still have the AFFF or Class B foam — a total of 32,000 gallons so far — much of it stored in 55-gallon drums or pales.

But there’s still no accurate record of exactly where they’ve used the likely carcinogen, or how much of it has contaminated groundwater, Sehlmeyer said.

Many fire departments have never used it, he said, while others, including Grand Rapids, Wyoming and Walker, say it’s been critical in putting out gas tanker fires.

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They used it in the mid-1980s to snuff out flames after a gas tanker flipped at US-131 and I-96 in Walker; and in the mid-1990s after a fuel tanker flipped on I-196 over the Grand River in Grand Rapids.

“In my whole career in the city of Grand Rapids, I wouldn’t run out of fingers for the number of times Class B foam was used in my 30-year career,” Sehlmeyer said.

The state last year found extremely high levels of PFAS in groundwater along M-60 in Cass County after the fire department there used AFFF foam to prevent an explosion after a gas tanker spill in April 2016.

Sehlmeyer said some fire departments have reported using the foam to put out tire fires.

It’s the same foam that airports, including the Gerald R. Ford International Airport in Cascade Township, were required to use for decades in training and to extinguish fires in plane crashes.

The fire marshal said the survey asked fire departments where they’d used the foam. Those sites would be reported to the DEQ for possible investigation, he said.

The state said fire departments should now use it only if absolutely necessary. “If you have to use it for life or limb, use it,” Sehlmeyer told the fire chiefs.

Also, if they use it, they’re now required to report it to the Michigan Department of Environmental Quality to make sure it’s cleaned up, he said.

The fire marshal said there’s no timeline for disposing of the PFAS foam from fire departments and said it will take legislation to pay for it.