Delaware delegation demands answers on PFAS contamination at Dover air base from Pentagon

Five water wells near Dover Air Force Base in Delaware are known to be contaminated with a class of toxic chemicals known as PFAS, including four whose existence was revealed last month.

Now Delaware’s congressional delegation is demanding answers and an action plan from U.S. Defense Secretary Mark Esper.

The wells are polluted with a class of chemicals contained in firefighting foam used at the base. They provide water to a shopping center, two homes and an office building.

The levels of PFAS there exceed federal drinking-water standards of 70 parts per trillion. PFAS are classified as “forever chemicals” because they don’t break down in the environment and can accumulate over time.

PFAS contamination also has been found on or near military bases in Pennsylvania, New Jersey and at hundreds of installations across the country where the firefighting foam was used.

The Dover base is providing affected workers and residents with bottled water while conducting further tests and analyzing data. But the letter to Esper from U.S. Sens. Tom Carper and Chris Coons and U.S. Rep. Lisa Blunt Rochester said they have “deep concern’’ about the contaminated wells.

“We note your commitment to ‘own’ the PFAS contaminations across Department of Defense installations and your recent announcement of a PFAS Task Force to tackle this issue,’’ the letter said.

“While we are encouraged by these actions and by the 436th Airlift Wing’s immediate efforts to mitigate exposure to affected communities through the provision of bottled water, we urge you to take additional actions to ensure that impacted residents and businesses have access to safe sources of drinking water going forward.”

The letter notes that aqueous film forming foam (AFFF) used at Dover and other bases “has been associated with a variety of adverse human health effects, including birth defects and immune system dysfunction” and pose “a severe public health concern.”

The letter also notes that a recent analysis by the Union of Concerned Scientists found that the Dover base had “the fourth highest reported PFAS contamination of over 100 tested military installations … As experts at Dover AFB acknowledge, contaminated groundwater may migrate and impact other water sources over time. It is imperative that the Department provide the necessary resources to the 436th Airlift Wing to prevent further PFAS contamination and address existing PFAS contamination.”

The delegation wants a slew of information, including details on the remediation plan, a map showing the wells, groundwater test results, and the feasibility of connecting to the municipal water supply. They went someone from the military to meet with affected residents and workers.

Blunt Rochester said Delaware’s top federal officials must act to protect residents and resources.

“We feel very strongly that everyone should be able to have safe drinking water and that’s our priority here,’’ Blunt Rochester said. “And when you find out through science that something is unhealthy and causing problems in communities, for people’s life and safety, our goal is to work forcefully to take care of it.”

The letter was sent a week ago and the Pentagon had not responded as of Wednesday, a spokeswoman for Blunt Rochester said.

Heather Babb, a Pentagon spokeswoman, said in an email to WHYY on Wednesday that “as with all congressional correspondence, we will respond to the authors of the letter.’’ She referred further inquiries to the Air Force.

Lt. Natasha Mosquera, spokeswoman at the Dover base, said in an email that beyond providing water and conducting more tests, “results will be provided to the residents once received and validated by the appropriate agencies.”

Mosquera said the Air Force has been dealing with water contamination questions since 2014, two years before the original contaminated well was discovered, “and we continue to analyze the need to sample additional areas that could be potentially contaminated. If and when we determine the need for further sampling, the Air Force will contact those residents directly.”

Beyond providing bottled water, further actions to assist residents could include “connecting the home to a public drinking water supply, or installing a treatment/filtration system on their private well,’ Mosquera wrote.

Joe Kowalski, a civilian environmental engineer who is remedial program manager at the air base, said officials are monitoring the affected wells and “actively and aggressively” pursuing the option of connecting the homes and business to the public water supply.

The home where a contaminated well was found in 2016 was given a carbon filtration system that the occupants are using and has tested below the acceptable limit, Kowalski said.

He said all five affected wells were found within 200 yards of the base boundary and that officials are scouring an area about a mile outside the base for other potential contaminated wells.

“We’re doing a very thorough search right now” in conjunction with state and federal regulatory official “to make sure we leave no stone unturned and making sure we are doing a thorough job.”