Recent testing shows elevated levels of PFAS chemicals at four drinking wells near the Dover Air Force Base.
The testing found perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) present in the wells at levels above the US Environmental Protection Agency’s health advisory of 70 parts per trillion (ppt).
The base’s firefighting foam was the cause of high PFAS levels found in area groundwater in 2016. At that time, the Department of Defense found levels of the chemicals in the groundwater at Dover Air Force Base at up to 2.8 million parts per trillion—40,000 times higher than the EPA limit.
Dover Air Force Base Remedial Project Manager Joe Kowalski says the base has since switched to a non-PFOS foam and the most recent high PFAS levels are a result of past use of the older foam.
“So, before a switchover from the old foam to the new foam. Anytime a contaminate gets in the groundwater, it only moves as fast as the groundwater so that can take years to travel off base," said Kowalski.
The affected wells provide water to a shopping center with five businesses, two residences and an office building. Kowalski says the owners have been notified and are being provided bottled water by the Air Force Base indefinitely.
Kowlaski adds the base may dig new, deeper wells for those affected, or hook them up to a public water supply and buy them home filtration systems.
He also notes the base is working with DNREC and the Environmental Protection Agency to potentially test more wells.
“We’re definitely looking at if it makes sense to test other wells in the area," said Kowalski. "That’s ongoing in our discussions right now to see if that makes sense to do.”
PFAS chemicals take a long time to break down in the environment and have been known to increase the risk of cancer and other health issues.
Sen. Tom Carper (D-Delaware) says the news of PFAS in the vicinity of the base should come as no surprise.
"As Dover residents know all too well, this is far from a new threat," he said in a statement Monday. "The Air Force’s actions this weekend represent only a tiny fraction of their long-term responsibilities."
Carper has been calling for stronger oversight and action on PFAS chemicals in the First State and nationwide.
"Disappointingly, the Department of Defense has not been confronting [the PFAS] issue with the urgency it deserves," said Carper. "DOD continues to advocate for weaker groundwater cleanup standards and downplay the extent of their cleanup liabilities."
PFAS have been found in other water supplies in Delaware.
The chemicals were discovered in public water supplies in New Castle in 2014. And last February the Air National Guard base at New Castle was one of eight sites chosen by the federal Agency for Toxic Substances and Disease Registry for an expansion of a national investigation into how the chemicals used on the base have affected ground water.
Elevated levels of combined PFOA and PFOS were found in public water in the Town of Blades in February, 2018.
This story has been updated.
