SPOKANE — The Washington Department of Ecology announced Monday it will begin collecting and incinerating stockpiles of a toxic fire retardant foam that was used by fire departments for decades before the state restricted its use in 2018.

The same type of foam was long used at Fairchild Air Force Base and blamed for contaminating West Plains water supplies, including the city of Airway Heights’ tap system.

Manufactured by chemical giants including 3M Co., the foam contains per- and poly-fluorinated alkyl substances, or PFAS, which have been linked with an array of health problems.

The man-made compounds, also used in products such as Teflon and Scotchguard, are sometimes called “forever chemicals” because they degrade extremely slowly in the environment and in the human body.

The Legislature last year banned the use of firefighting foam containing PFAS chemicals for training purposes, though it may still be used for fires involving flammable liquids.

Starting in July, it will be illegal to sell, distribute or manufacture the foam in Washington, with exceptions for the military, federally certified airports, petroleum refineries and some chemical plants.

The Legislature also gave the Ecology Department $1.7 million to safely dispose of any remaining stockpiles of the foam, said agency spokesman Andrew Wineke.

The Ecology Department is working with the state fire marshal and the Washington Fire Chiefs Association to spread word about the program. A department contractor, Clean Harbors, will collect foam from fire departments and incinerate it at one of three facilities in Utah, Texas and Arkansas, Wineke said.

“The only other real option is to put it in a hazardous waste landfill, but we really didn’t feel comfortable with that,” he said. “These are called ‘forever chemicals,’ after all.”

Recommended for you