Glenn Carter, 74, is going to have the Navy test his private well in Warminster. He said he was not surprised by the contamination, having worked on the Bucks County base decades ago.
"Back in the late '50s, nobody worried about stuff like this," he said. "Everything got buried."
Others were more concerned. Paul Lang and his neighbors said they had been suspicious after seeing so many cases of cancer in their neighborhood in the last few years - pancreatic, leukemia, liver, breast, lymphoma.
"You don't know whether it's related or not, but you certainly wonder," said one of Lang's neighbors, who did not want to give her name.
Animal studies have linked PFOS to increased rates of cancer and reproductive and developmental problems.
Karen Johnson, who heads the testing for the EPA, said authorities had known about PFOS for several years but "didn't have the lab capacity to test for it until 2013." The compound is so slippery and hard to work with that "the lab can't have any equipment that's Teflon-related - it's got to be glass."
In Warminster, one well was found to have three times the recommended levels. It was shut down this month, along with another well that registered just under the recommended level.
In Horsham, one well tested at three times and another five times the recommended level for PFOS. The township Water and Sewer Authority shut down the two wells in early August and has agreements to import water from neighboring towns as needed.
Tina O'Rourke, business manager for the Horsham water authority, said the two wells produced about 26 percent of the town's water supply. She estimated it would be at least a year before the situation is resolved, either by treating the two wells or "replacing that water in some other manner."
Greg Preston, who works with the Navy's Base Realignment and Closure program, said the Navy was "100 percent committed to the problem," though the Navy sold the Warminster base in 2000 and has been trying since 2006 to unload the Willow Grove base. "We don't cut and run when we sell the deed."
Horsham's redevelopment agency, which had hoped to have part of the property in early 2015, cannot take ownership of the base until the PFOS issues are resolved - which could take from a few months to a couple of years.
"It's a very big unknown. A very big unknown," said Michael McGee, executive director of the redevelopment agency.
Here is a look at the contaminants involved in the cleanup:
What is it? Perfluorooctane sulfonate (PFOS) is one of the most common types of perfluorinated compounds in the United States. They were developed in the 1950s and used for decades in products such as firefighting foam, nonstick coating, textiles, semiconductors, and paper products. PFOS is no longer manufactured in the United States.
Built to last. Because the compounds are designed to repel water and fatty substances, they don't wash away or biodegrade naturally. They can be hard to test for, hard to clean up, and easily spread. The compounds have been detected in humans, fish, and other animals nationwide.
Health effects. Studies of rodents, monkeys, and other animals have found the compounds build up in the liver and kidneys, and can lead to cancer and reproductive and developmental problems. A 2009 provisional health advisory by the EPA said PFOS above 0.2 parts per billion "may cause adverse health effects in the short term (weeks to months)." The agency is in the final stage of peer review for formal guidelines on human exposure.
SOURCE: U.S. Environmental Protection Agency