"It doesn't take a lot of contamination to cause a big problem," Bishop said.
In addition to investigating the contamination's source, the DEP is testing elsewhere to ensure the problems aren't more widespread. The geographic area is known as the "contamination plume."
Ninety residential wells in the Tomstown, Pa., area were tested by the DEP, and 26 showed TCE contamination. A dozen showed more than five parts per billion - the public drinking standard - and strongly warrant the bottled water, officials said.
One home on Mentzer Gap Road, where the well tested at more than 25 parts per billion, will receive a carbon treatment system from the DEP within a week. TCE at that concentration is toxic when inhaled, Bishop said.
Property owners who spoke at the meeting questioned the cost and effectiveness of purchasing their own carbon treatment systems, which require $300 to $500 of annual maintenance.
While official recommendations are withstanding, DEP and township officials are talking about installing public water lines for the greatest protection. They made state Rep. Todd Rock, R-Franklin, and a representative of state Sen. Terry Punt, R-Franklin, aware of the several million-dollar possibility.
Contamination was discovered when test wells were drilled for a new housing development known as Mentzer Meadows. The tests were, as one hydrogeologist called them, "overly conservative" in that volatile organics were tested in addition to bacteria and nitrates.
The suite of results for volatile organics included peaked levels of TCE, which was primarily used as a solvent from the 1960s until the 1980s. It also was found in adhesives, paint removers and Scotchgard.
"It's still not outlawed," said Arthur L. Dalla Piazza, who oversees the DEP Hazardous Sites Cleanup program.
However, laws have placed limits on human exposure to TCE, he said.
Health problems resulting from TCE are thought to come from long-term exposure, DEP Environmental Cleanup Program Manager John F. Krueger said.
However, he conceded the TCE could have been in Quincy Township wells for decades.
"The odds are this TCE was introduced before the 1990s," said Jeff Peffer, a hydrogeologist with AquaFusion, a subcontractor for Martin & Martin Engineering of Chambersburg, Pa.
"It can fluctuate, so our practice is to come out periodically to resample," Bishop said.
Bottled water will be distributed until the investigation is complete, officials said.
Bishop said methods of speeding up the degradation of TCE can eventually create carbon dioxide from it.
The DEP has been working with six TCE sites in the state, including ones in Lancaster and Berks counties, Dalla Piazza said. About 315 federal Super Fund sites, including Letterkenny Army Depot in Chambersburg, Pa., have tested positive for TCE, he said.
What is tricholoroethylene?
Tricholoroethylene (TCE) is a colorless liquid once used in popular solvents, adhesives and paint removers. It was mostly used from the 1960s until the 1980s, when new regulations caused industries to seek alternatives.
TCE particles are heavier than water particles, so they can sink to the bottoms of wells. The chemical can stick to water particles and be transported through an aquifer.
Evaporation of TCE creates inhalation problems for humans.
The Agency for Toxic Substances and Disease Registry reported that breathing small amounts of TCE can cause headaches, dizziness, lung irritation and difficulty concentrating. Larger amounts can impair heart function or cause unconsciousness or death, the agency reported.
Drinking TCE over a prolonged period can result in cancers, liver and kidney damage, and impaired immune system function.
TCE also can cause skin rashes on contact.
Source: The Pennsylvania Department of Environmental Protection and The Agency for Toxic Substances and Disease Registry