SPOKANE, Wash. --- The water in Airway Heights is not safe to drink, and what caused it may have been acids found in firefighting foam used by Air Force trucks for more than 40 years at Fairchild Air Force Base.

Fire training at the base was restricted to the southeast part of the base, so the Air Force initially tested private wells that bordered that area. Officials said they found contaminants in some of those wells, and based on the results, expanded their testing.

Officials tested the Airway Heights water and that is when they found the elevated levels of two different acids (PFOS and PFOA). The acids are classified by the EPA as emerging contaminants.

Col. Ryan Samuelson, the Fairchild Air Force Base Commander, spoke with KREM 2 on Wednesday and said the Air Force wants to be transparent as they work to determine the extent of the contamination.

When asked if he knew the extent of the problem, he said things were still “premature.”

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“We went further south into Medical Lake, again not validated, but the preliminary indicates that Cheney and Medical Lake are not impacted by any potential use that we think that would come for our firefighting training,” he said.

Samuelson said they have not used the chemical in more than two years at the base. The chemicals were used from 1970 until recently, officials said.

“So areas that still have contaminants we don't know how long they've been there and we don't know how long it will take to mitigate them,” he explained. “It's a very persistent chemical, unfortunately. And that's why continue to do monitoring.”

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"The EPA actually recognizes this as an emerging contaminant so it's unregulated, it's ungoverned right now,” Samuelson said. “What I think the Air Force and many DOD installations realized we have been using something that could contaminate. If the EPA establishes limits later on or regulates the use of them the Air Force wanted to be ahead of that."

The City of Airway Heights announced Wednesday night they think it will take 10 days to flush the water system of the contaminants. So far, 40,000 gallons of water has been distributed both at pickup points and delivered to those who can’t leave their homes, city officials said.

Albert Tripp, the Airway Heights city manager, said the reason for the delay in getting the water cleared is because they must treat the water before discharging it from the system.

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Officials said tap water is safe for activities where water will not be ingested such as bathing, doing laundry and washing dishes. Residents and businesses in Airway Heights that are east of Hayford Road are not affected because their utility service is through Spokane.