The state Department of Environmental Protection is trying to determine the source of an unacceptable level of contamination found in drinking water in Doylestown, officials said Tuesday.

A public drinking well along Easton Road in the Cross Keys area was shut down last month after inspectors found levels of perfluorinated compounds higher than newly announced federal standards.

Public drinking water there is now safe, officials said. But they are trying to identify how the well became contaminated with PFOS and PFOA.

The chemicals are the same ones affecting water supplies in Horsham, Warrington, and Warminster, where contamination was caused by firefighting foam used at two former naval air stations. But the Doylestown well is miles from those sites and has not been connected to the foam.

PFOS and PFOA were used for decades not only in firefighting foams, but also in nonstick cookware, carpeting, furniture, and other products. They have been linked to health problems including testicular and kidney cancers, liver damage, thyroid disease, and high cholesterol.

The DEP will investigate whether there have been manufacturing facilities or major fires near the Doylestown well, said Virginia Cain, a department spokeswoman. It will also contact private well owners within a mile of the well, and offer to test their wells and supply them with bottled water.

"Right now our priority is just making sure we get these wells tested," she said.

While DEP searches for a "responsible party" for the contamination, Cain said, DEP's Hazardous Sites Cleanup Fund will cover the cost of the work.

610-313-8116 @Lmccrystal