JOINT BASE SAN ANTONIO-LACKLAND, Texas – The Air Force Civil Engineer Center has completed installation and testing of a water filtration system that reduces Perfluorooctanoic Acid and Perfluorooctane Sulfonate from drinking water near Luke Air Force Base, Arizona, to levels below the Environmental Protection Agency’s lifetime health advisories.
The ion-exchange water filtration system installed at the Valley Utilities Water Company’s Bethany Hills West location will remove PFOS and PFOA from drinking water going to homes next to the installation.
In early 2021, AFCEC quickly established a bottled water distribution site to assist more than 5,000 impacted residents after the Air Force verified PFOS and PFOA was present in drinking water supplies at levels above the EPA’s lifetime health advisories of 70 parts per trillion in drinking water, said Shimi Mathew, AFCEC Nellis Installation Support Section chief.
The system is capable of treating up to 1,200 gallons of water per minute and has the capacity to treat a about 657 million gallons before it needs routine maintenance. It recently completed all necessary performance testing and meets all required levels for drinking water, she said.
With the system active, the Air Force, the bottled water provider and Valley Utilities are notifying customers of the system activation and the transition from bottled water, Mathew said. All bottled water customers will have up to four weeks to complete the transition.
The ion exchange system is new to Arizona and gaining traction as a tool for addressing instances of PFOS and PFOA testing above EPA’s lifetime health advisories, said Hunter Anderson, an environmental scientist with AFCEC’s Technical Support Branch.
Anderson explained that ground water enters one of the large Ion-Exchange vessels and the dissolved PFOS/PFOA molecules in the water are adsorbed to a special resin that fills the vessel. The system removes PFOS/PFOA molecules from the ground water and retains them in the resin while clean water is pumped out of the vessel and into the Valley Utilities Water Company general distribution system.
The resin will continue to trap particles for up to 10 years before requiring maintenance. The Air Force will conduct quarterly sampling to monitor the life of the resin and replace it when needed, said Cindy Cash, AFCEC Emerging Contaminants program manager.
Mathew said the on-going partnership between the Air Force, Maricopa County and Arizona Department of Environmental Quality has been vital in getting the ion-exchange system installed, tested and verified.
The work to understand more about potential impacts of PFOS/PFOA is ongoing.
“This (system installation) represents the Air Force acting quickly to address a potential imminent risk to public health,” Cash said. “Now we are conducting extensive field work to better understand where we are and where we need to be.”
With the system in place, AFCEC is moving into the remedial investigation stage of the PFOS/PFOA response.
Kimberly Horsley, Remedial Project manager, leads the team that is in the field gathering data to build a big-picture view of the impact PFOS/PFOA has had on the areas surrounding Luke.
“The goal of the investigation is to fill in the gaps of our understanding,” she said. “We will expand our response if we need to as we learn more.”
The investigation is expected to continue through 2024.
For additional information on the Air Force’s response to PFOS and PFOA, visit https://www.afcec.af.mil/WhatWeDo/Environment/Perfluorinated-Compounds/