The Dover Air Force Base is in the early stages of a long-term cleanup project to improve water quality and mitigate forever chemical contamination.
The base restoration program manager LeRoy Demarest said there are other contamination sites but these three have the highest potential impact to human health because the contaminants have migrated.
Demarest’s team installs filtration systems in places with dangerous PFAS and PFOA levels.
“Ideally, we would move to a more enduring solution,” Demarest said. “Those things would include connecting to municipal waterways or water lines, like the City of Dover, Tidewater. And we're working on a partnership with the city right now to connect some of those properties.”
Staff identified several sites where contaminants including PFAS entered the water supply. The plumes attributable to the Air Force include an old fire training area on the west end of base, Hangar 945 on the north end and a 2006 C-5 crash site on the south end.
The EPA changed the maximum contaminant level for PFAS from 70 parts per trillion to 4 parts per trillion in 2023.
Four private drinking water wells near base had levels up to 2,400 times the federal lifetime health advisory in 2019.
Demarest attributes some of the PFAS contamination to Aqueous Film Forming Foam, a firefighting foam. The Delaware General Assembly passed a resolution in 2023 requesting the Delaware State Fire School dispose of AFFF and exchange it for an alternative at no cost.
"To be very clear, in this PFAS investigation, to this point, we have focused on firefighting foam," Demarest said. "There are an array of other PFAS compounds — some of which were probably used by Air Force or DOD — but there are compounds that are used in the households all the time that just worked well for what they were."
Demarest said the Air Force did not know AFFF was ecologically harmful at the time it was used, including the 2006 crash.
The Air Force has replaced two wells into deeper confined aquifers with no known contamination.
“Moving forward, we'll probably not move that way, just to prevent any risk of maybe drawing that down into a clean aquifer,” Demarest said.
For now, the team at the base will continue with its short-term fix of installing Point of Entry Treatment Systems, which work by using granulated activated carbon or resin that filters out PFAS, PFOA and other contaminants.
The filtration system has to be checked periodically so the team knows when to replace the carbon.
Demarest’s team is working on a project that, if implemented, would put a pump and treat system at the north end of base, which has the highest contamination. That would mitigate the movement of future contamination.
Demarest said the Department of Defense, the Air Force and the Environmental Protection Agency are working together to find more methods to address this issue.
He added there is technology being tested that will be able to break down these forever chemicals and offer a shorter term solution.
“And we can restore aquifers or restore waterways to a more pristine situation – as much as a pristine situation you can have in an industrial urban area,” Demarest said. “But I totally recognize the time that it can take. So we want to be as steadfast with the science that we have and as it evolves, implement it.”
Demarest said this is brand new science and his team will continue working on the issue with tools currently available.
