PETERSON AIR FORCE BASE, Colo. — The military said Wednesday an Air Force Base in Colorado did not discharge thousands of gallons of water contaminated with toxic chemicals into the wastewater treatment system of Colorado Springs, as it originally feared.
Some water tainted with the chemicals — which are used in firefighting foam — did disappear at Peterson Air Force Base, but it was likely due to evaporation during hot weather, Col. Douglas Schiess said.
The Air Force launched a criminal investigation after firefighters reported on Oct. 12 that 150,000 gallons of water used in firefighting exercises apparently drained from a storage tank into the city sewer system.
But investigators determined that 20,000 gallons of water was unaccounted for, not 150,000, and that "evaporation was determined to be the likely culprit," rather than a discharge, Schiess said. The evaporation apparently occurred from an open pit where the water is pumped for firefighting exercises.
Schiess said the firefighters overestimated how much wastewater was in the tank and that, along with miscommunications, led commanders to believe that 150,000 gallons had drained into Colorado Springs' sewers.
City officials had said there was no threat to drinking water because it flows through a separate system.
The water evaporated over a few weeks from an open pit surrounding a dummy aircraft that firefighters use for training. The water is moved back and forth between the tank and the pit, officials said.
Schiess said the chemicals would have remained in the pit rather than evaporating with the waters.
The chemicals are called perfluorinated compounds or PFCs. They have been linked to prostate, kidney and testicular cancer, along with other illnesses.
Firefighting foam containing PFCs has been used at military installations nationwide. PFCs have also been used in non-stick cookware coatings and other applications.
The Air Force announced in August it would switch to some another type of foam believed to be safer. Peterson Air Force Base fire trucks have already switched over to the alternate foam, Schiess said.
It will take about 14 months for the Air Force to replace the old type of foam in all of its fire trucks, said Air Force Deputy Assistant Scretary Mark Correll, who appeared with Schiess at a news conference Wednesday.
The Air Force is also replacing the foam used in fire-suppression systems in hangars and other buildings, Correll said. He didn't know how long that would take.
The Air Force is also investigating whether Peterson is the source of PFC contamination found in well water in two other nearby communities, the town of Fountain and an unincorporated community called Security-Widefield. Crews are drilling test wells to help determine whether the PFCs seeped from Peterson into underground water that feeds wells.