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 E.P.A. — 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 E.P.A. is preparing to designate these chemicals hazardous substances, meaning areas contaminated can be designated Superfund sites, formalizing the cleanup effort.

The E.P.A. 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 E.P.A., said major objections were raised by the Pentagon, as well as by NASA, another major user of PFAS, and the Small Business Administration.