The U.S. Environmental Protection Agency (EPA) has given the U.S. Air Force and the Arizona Air National Guard 60 days to come up with a remediation plan, after groundwater samples from an airport-area facility in Tucson, Arizona, were found to be 5,300 times the allowable amount for PFAS.
While the site’s water well field is not currently delivering groundwater to the city’s water utility, the EPA said it believes the wells could be brought back into service following adequate remediation.
Tucson Water already shut down its treatment plant on the property in 2021 over PFAS concerns.
The Tucson airfield area has a history of contamination from defense and industrial activities. It is already categorized as a superfund remediation site, dating back to 1983, referred to as the Tucson Airport Remediation Project (TARP). The site is contaminated with a number of pollutants such as trichloroethylene, or TCE, formerly used as a general-purpose solvent and degreaser. Another contaminant found at the site is 1,4-dioxane.
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Despite the EPA’s emergency administrative order being issued on May 29, it wasn’t until late July that the U.S. Air Force pushed back publicly on the order’s sense of urgency, and questioned its legality. U.S. Air Force officials have filed a formal request to the EPA noting that other parties have used PFAS at the airport site, and that health protection concerns lie with state and municipal authorities. They also stated that there is no imminent danger to human health to justify such a short remediation response period for the underground water contamination.
Samples taken at the airfield water treatment plant showed concentrations of PFAS as high as 53,000 parts per trillion, which is 5,300 times the allowable amount, the EPA stated.
The EPA says it issued the order pursuant to the Safe Drinking Water Act.
Tucson has taken several actions over decades to reduce contamination around the airport site and the aquifer. Notably, Tucson Water installed an Advanced Oxidation Process Water Treatment Facility adjacent to the TARP facility in 2014. The utility also installed a granular activated carbon (GAC) treatment to address residual hydrogen peroxide in the area water.
“The effect of PFAS on the TARP GAC filters has created an unanticipated and unreasonable impact to Tucson Water’s operation of the TARP to ensure drinking water quality for the residents of Tucson,” the EPA states in its order.
