All News Releases By Date

EPA Samples for TCE Vapors under Perkasie Homes

Release Date: 4/14/2004
Contact Information: David Sternberg (215) 814-5548

David Sternberg (215) 814-5548

PHILADELPHIA - The U.S. Environmental Protection Agency today announced the completion of sub-surface vapor sampling beneath 16 homes in Perkasie Borough. The sampling was done to determine if sub-surface soils containing trichloroethylene (TCE), a probable human carcinogen, could be releasing vapors into homes at levels of health concern. EPA expects to make the sampling results available to property owners in May 2004.

EPA’s sampling in the area in November 2003 indicated that vapors containing TCE, an industrial solvent, were present in sub-surface soils in the Perkasie area. Past industrial activity left parts of the area’s groundwater contaminated with the solvent. Vapors from the TCE in the groundwater can migrate through the soil and have the potential to infiltrate into homes, causing a potential health risk.

EPA selected these 16 homes because previous nearby sampling results indicated they could be at risk for vapor intrusion. This selection was based upon the screening methods in the draft EPA vapor intrusion policy.

The samples were taken by inserting a 1½ inch diameter rod at an angle beneath the basement slab of a home, creating a hole, and then implanting a 21 inch mesh collector tube to collect the vapors. Through tubing which goes from the mesh collector tube to the surface, an air sample is collected in a metal canister and then sent off to a laboratory for analysis. If sub-slab vapor sampling indicates TCE vapor at levels of concern beneath a home, EPA will determine if interior sampling is necessary.

Any home found to be contaminated with TCE vapors at levels of health concern can be easily remedied by a vapor reduction system similar to the ones used when radon gas is found to be present. These systems draw vapors out of the surrounding sub-surface soils and vent them away from the home, thus significantly reducing or eliminating vapor intrusion.