WASHINGTON — Facing billions of dollars in cleanup costs, the Pentagon is pushing the Trump administration to adopt a weaker standard for groundwater pollution caused by chemicals that have commonly been used at military bases and that contaminate drinking water consumed by millions of Americans.
The Pentagon’s position pits it against the Environmental Protection Agency, which is seeking White House signoff for standards that would most likely require expensive cleanup programs at scores of military bases, as well as at NASA launch sites, airports, and some manufacturing facilities.
Despite its deregulatory record under President Trump, the EPA has been seeking to stick with a tougher standard for the presence of the chemicals in question in the face of the pressure from the military to adopt a far looser framework.
How the administration resolves the fight has potentially enormous consequences for how the United States is going to confront what a top official at the Centers for Disease Control and Prevention has called “one of the most seminal public health challenges” of the coming decades.
The problem is not limited to military bases. An estimated 5 million to 10 million people in the country may be drinking water laced with high levels of the chemicals, known as Per-and polyfluoroalkyl substances, or highly fluorinated chemicals. They include thousands of people who live near military bases in states including Michigan, Pennsylvania, and Massachusetts.
PFAS, as the chemicals are most commonly called, are present in a vast array of products, including food packaging, nonstick pans, clothing, and furniture. They have been linked in recent years to cancers, immune suppression, and other serious health problems.
But since the 1970s, the Defense Department has been one of the most frequent users of PFAS. The chemicals are a key ingredient in firefighting foam employed at bases nationwide, with military crews spraying large amounts during training exercises (and on emergency calls) into unlined basins that drain into the soil and then into groundwater.
In 2017, after military communities around the country began to report alarming levels of PFAS in their drinking water, the Pentagon confirmed that there were 401 known military facilities in the United States where it was used.
Further study by the Pentagon concluded that the PFAS contamination had turned up in drinking water or groundwater in at least 126 of these locations, with some of them involving systems that provide water to tens of thousands of people both on the bases and in nearby neighborhoods. In some instances, the Defense Department is providing temporary replacement water supplies.
The military and many airports nationwide have relied on PFAS-based firefighting spray because it can more quickly put out liquid fuel fires and it works when mixed with both fresh water and seawater.
The Defense Department has been moving in recent years to phase out the use of the most worrisome version of these chemicals and replace them with a formulation that does not break down in the environment as easily or build up as much in the bloodstream if it ends up in drinking water. But this replacement chemical is also generating health concerns.
The EPA — after intense criticism from communities facing contaminated water, as well as from both Democrats and Republicans on Capitol Hill — is moving toward creating two new PFAS standards to address the problem nationwide.
The first would establish guidelines for when cleanups will be required at federally controlled sites to try to prevent that contamination from reaching drinking water supplies.
The second would set a legally binding, maximum allowable drinking water level for PFOS and PFOA, two of the most common forms of PFAS. Separately, the EPA is preparing to designate these chemicals hazardous substances, meaning areas contaminated can be designated Superfund sites, formalizing the cleanup effort.
The EPA completed its work on the first step, the proposed groundwater cleanup standard, last August and transferred it to the White House Office of Management and Budget for approval, with a prediction that it would be finalized and made public by last fall.
But federal officials briefed on the negotiations, including the office of Senator Thomas R. Carper, Democrat of Delaware, the ranking member of the Senate committee that oversees the EPA, said major objections were raised by the Pentagon, as well as by NASA, another major user of PFAS, and the Small Business Administration.
Among the sites that could be subjected to a cleanup are NASA’s launch sites at Cape Canaveral, Fla., and Wallops Island, Va.
Patrick M. Shanahan, the acting secretary of defense, was asked about the matter Thursday during a Senate Armed Services Committee hearing. Shanahan told Senator Jeanne Shaheen, Democrat of New Hampshire, where there is also a military-base related contamination problem, that he was not aware if the Pentagon was trying to weaken the groundwater standard. But he said he would look into it “very quickly.”
Frustration is only increasing across the United States as the Trump administration moves slowly to confront the challenge.
Just Wednesday, the Vermont Senate voted 29-0 in favor of legislation that would create a new limit on PFAS in drinking water that at 20 parts per trillion is far tougher than even the current EPA drinking water advisory standard. The legislation would also require annual testing by public water systems in the state.
The move was motivated in part by widespread contamination caused by a manufacturing plant in Bennington, Vt., called Chemfab, that once made fabrics and roofing materials coated with the chemicals. Chemfab is now closed.