WASHINGTON — Maryland military facilities are in the early stages of remedial investigations into “forever chemicals” that jeopardize drinking-water supplies in groundwater after a September report by the Department of Defense identified hundreds of military sites across the country as at risk for such chemicals.

The facilities include high-profile Joint Base Andrews, home to Air Force One, as well as Aberdeen Proving Ground, Fort Meade, Fort Detrick, Patuxent River Naval Air Station and the Naval Research Laboratory-Chesapeake Bay Detachment in Calvert County.

The potential contamination involves chemicals known as per- and polyfluoroalkyl substances, or PFAS, which are a family of thousands of chemicals used in firefighting foams, heat-resistant products and many other items.

The Pentagon has been under fire for years from communities, environmental organizations and Congress for failing to recognize the dangers of hazardous chemicals used in military operations and for being slow to clean up facilities.

The DOD has initiated remedial investigations at 275 Defense Department and National Guard sites for potential PFAS contamination, 245 of which, including 11 locations at 10 Maryland sites, are close to groundwater aquifers.

Some of these sites are part of aquifers that serve as primary or secondary drinking-water sources.

Robin Broder, deputy director of Waterkeepers Chesapeake, said PFAS is a known problem around military bases and is more likely to become a human health issue by contaminating water and crops.

Military bases often use firefighting foam in emergencies and training exercises. Foam that still contains PFAS can seep into soil, evaporate into the air or run off into waterways.

PFAS runoff can also contaminate fish and harm people who eat the contaminated seafood.

In 2021, the Maryland Department of the Environment found elevated concentrations of perfluorooctane sulfonic acid, or PFOS, a chemical in the PFAS family, in redbreast sunfish, yellow bullhead catfish and largemouth bass in Piscataway Creek, a tributary of the Potomac River.

“Cleanup efforts are challenging and costly,” said Dr. Arthur Daniel Jones III, a professor in Michigan State University’s Department of Biochemistry and Molecular Biology and associate director of the MSU Center for PFAS Research.

Such chemicals are difficult to remove from the environment after contamination and have very few natural processes to break them down, he said.

“Part of the challenge is that … we certainly don’t know very much about how the mixtures of PFAS … are toxic,” Jones said. “There are PFAS in foods, household products. ... Almost every person on the planet is already contaminated by PFAS.”

Exposure or consumption of PFAS has other potential health risks, including fertility and immune system issues, developmental delays in children, increased cancer risks and hormone interference.

The Aberdeen Proving Ground, an Army facility, states on its website that tests of its drinking water showed PFAS contaminants below the Environmental Protection Agency’s advisory level of 70 parts per trillion.

“The Army is committed to ensuring quality drinking water is provided to its soldiers, family members, and civilians,” the website says. “We continue to work with our state and federal partners and will ensure the community is kept updated on the status of our investigation.”

The Army site is in the planning stages of the remedial investigation, said Quentin Johnson, Aberdeen’s director of public affairs. Similarly, Joint Base Andrews emphasized that its drinking water, which comes from the WSS Water, is unaffected by PFAS.

According to a statement by the Air Force Civil Engineer Center at the Joint Base Andrews field office, the extent of PFAS impacts on groundwater at the site is unknown, but groundwater samples have indicated the presence of these chemicals. Further samples are being collected to determine the degree of contamination.

“This is a slow process complicated by the fact that we are sampling at an active airfield on an active military installation with active missions critical to national security,” said the statement. “At JBA, it takes months to collect samples and get back results.”

The Air Force, however, has removed all fire-suppression systems that contained PFAS chemicals from the base, according to the statement.

Joint Base Andrews said it has informed local communities, health departments and government bodies about the PFAS issue.

Two sites at the Naval Research Laboratory-Chesapeake Bay Detachment will be investigated by the Navy’s Environmental Restoration Program for PFAS: a fire-testing area and a former firehouse, according to a statement from the Naval Facilities Engineering Systems Command Atlantic.

The fire-testing area is already under investigation, and the firehouse will be studied in 2024 to “investigate the nature and extent of the PFAS and assess potential human health and ecological risks,” the statement said.

In 2018, the Navy’s off-base water sampling in communities near the Chesapeake lab revealed no perfluorooctanoic acid, also called PFOA (another chemical in the PFAS family), or PFOS levels above the Environmental Protection Agency limit of 70 parts per trillion.

“The Maryland Department of the Environment and the U.S. Environmental Protection Agency provide regulatory oversight on the remediation of contamination, whether from PFAS or other contaminants, at military sites within the state,” said Jay Apperson, a representative from the Maryland Environment Department.

The state, the EPA, Navy personnel and community members are actively involved in restoration advisory boards, ensuring that families living near these facilities are informed about environmental issues and the steps being taken to address them.

Rep. Jamie Raskin, D-Md., a member of the Congressional PFAS Task Force, emphasized the urgency of addressing PFAS contamination in a recent statement.

“I recently joined my colleague Rep. Chrissy Houlahan (D) of Pennsylvania and many others in urging the Department of Defense to swiftly address its growing backlog of military sites contaminated with PFAS,” Raskin said. “We also urged the DoD to adequately fund cleanup efforts at contaminated sites across the country, including the White Oak Naval Surface Warfare Center in my district and several other sites in our state.”

Jones said there aren’t many “good” ways to get rid of PFAS.

“Even if you’re drinking water that has very low levels of PFAS in the water, most of what you drink today is going to be with you for years,” he said. “And there are very few natural processes that break down PFAS, so in essence, that’s why they’re called ‘forever chemicals.’”

Other Maryland sites where PFAS investigations are underway or planned are the Naval Surface Warfare Center Carderock Division-Annapolis Detachment, the Naval Surface Warfare Center Indian Head Division, U.S. Naval Electronic Systems in St. Inigoes and the Martin State Air National Guard Base in Middle River.