Project: Vapor intrusion and VRAP


St.Germain conducted an environmental and historical file review for a property in downtown Lewiston, Maine that had three buildings on it. The 1957 Sanborn Fire Insurance Map showed the presence of a dry cleaner adjacent to the property that was labeled “solvent tank in basement”. Subsequent sub-slab vapor samples indicated that PCE vapor was present beneath the building adjacent to the former dry cleaner and another building on the property several hundred feet away. The third building on the property did not show elevated PCE in the sub-slab vapor. The buyer of the property wanted to ensure the safety of their tenants and relief from environmental liability .


fire insurance map imageSt.Germain screened soil vapor next to the former dry cleaner and the two buildings on the property where sub-slab data showed the presence of PCE. After additional lab sample collection, we concluded that there was a groundwater plume of PCE emanating from the former dry cleaner and beneath two of the buildings on the buyer’s property.  Subsequent indoor air sampling showed slightly elevated levels of PCE in the two downgradient buildings but not in the third more distant building that was not near the source of the suspected plume.

On behalf of the buyer, St. Germain applied to the Maine Department of Environmental Protection (Maine DEP) Voluntary Response Action Program (VRAP) and recommended that there was no risk to the distant building, but that a PCE plume was generating vapors that were affecting the other two buildings. The Maine DEP agreed and required sub-slab depressurization systems for the impacted buildings but no action was required for the third building.