The Air Force said last week that it would stop using the potentially dangerous firefighting foam that over years contaminated some local water supplies, but no other military branch has a public plan to ban the foam at its bases.

Since 2014, 16 wells have been closed in Bucks and Montgomery Counties after they were found to be tainted with PFOA and PFOS, chemicals linked to cancer that leached into local water supplies from firefighting foam used at two now-closed naval air bases. The military is investigating potential contamination at more than 600 bases nationwide.

The Air Force announcement came as elected officials are pushing for blood tests for residents of Warminster, Warrington and Horsham Townships, and muncipalities are taking extra, costly steps to ensure that their water is clean.

The Defense Department has not required its other branches to follow the Air Force's lead.

Instead, the military ordered its departments in January to get rid of the toxic firefighting foam "wherever possible as long as there is no undue impact on the DoD mission," Lt. Col. James B. Brindle, a Defense Department spokesman, said Friday. He did not say how much of the foam had been disposed of under that policy.

January's internal Defense Department memo, a copy of which was obtained by the Inquirer, called for the foam to be removed only "where and when practical to do so," with no other instructions or requirements.

The Air Force will use a new firefighting foam that contains no PFOS, but still has other perfluorinated compounds, known as PFCs, and traces of PFOA. The product is considered more "environmentally responsible," the Air Force said in a statement.

Last October, the military asked contractors for proposals for developing a foam that contains no PFCs. Research is expected to begin this year.

The Air Force, which operates an Air National Guard station on part of the former Willow Grove base, is paying for cleanup in one section of Bucks County. It had dedicated $8.3 million as of June. The Navy, responsible for the rest of the cleanup, had spent $19 million by midsummer.

The dangers of PFCs have been known to some extent for more than two decades, but the military has not ceased their use - not after the Environmental Proection Agency asked major commercial manufacturers to phase out production of the chemicals in 2006, and not after they were first detected on the two Philadelphia area bases in 2011.

"I welcome the Air Force's decision," U.S. Sen. Bob Casey (D., Pa.) said in a statement Friday. "It is overdue, and I urge the other military services to promptly follow suit."

Casey and the rest of the Keystone State's congressional delegation have been pushing the Defense Department and the EPA for more answers and more action since May, when the EPA lowered the amount of the compounds considered safe to drink, resulting in the closure of more wells in Horsham, Warminster, and Warrington Townships.

Last month, the Navy denied lawmakers' requests to pay for blood tests, saying the federal Agency for Toxic Substances and Disease Registry does not recommend it.

Casey said Friday that he planned to push for a military-funded health study by the Centers for Disease Control.

A report released last week analyzing cancer data in Warrington, Warminster, and Horsham found that instances of some cancers, including bladder and testicular cancer and non-Hodgkin's lymphoma, had increased from 1985 to 2004, but did not qualify as a cancer cluster. The results make "an inconclusive picture," said the report, prepared by the Toxic Substances and Disease Registry at the request of local and federal officials.

"This inconsistent pattern makes it difficult to determine if these results are meaningful," the report said. "Researchers need larger numbers of persons in order to have a more accurate and representative picture of the reality of the community."