Toxic firefighting chemicals were found in drinking water north of Fairchild Air Force Base at concentrations of up to 409 parts per trillion, nearly six times the level that federal regulators believe is safe, a base official said Friday.
Officials had said Thursday that 21 private wells north of the base showed concentrations above the U.S. Environmental Protection Agency’s recommendation of 70 parts per trillion, but precise figures were not immediately available.
The perfluorinated chemicals were key ingredients in a foam that base firefighters used for decades to practice dousing aircraft fires near the southeast corner of the base. The chemicals seeped into groundwater from that training site, contaminating private wells and wells that supply the city of Airway Heights’ tap water.
Fairchild’s public affairs chief, 1st Lt. Tanya Wren, said the chemical concentrations in the 21 wells ranged from 75 to 409 parts per trillion. Nineteen other wells tested this month showed lower concentrations, and 10 showed no trace of the compounds.
Until Friday, Fairchild officials had not disclosed the numerical results of any well tests. But in May, a city official said two wells in Airway Heights showed levels above 1,100 parts per trillion – more than 15 times the EPA threshold.
Wren said affected residents are being supplied with clean water.