Cleanup to Begin at Former Shamrock Dry Cleaners Site in Derry, N.H.

Environmental cleanup work will begin next month at the former site of Shamrock Dry Cleaners in Derry, N.H. The site, located at 3 Railroad Ave. in Derry, was a commercial dry-cleaning business between 1955 and 2001.

The U.S. EPA and the N.H. Dept. of Environmental Services (NHDES) will host an open house from 6 - 8 p.m. on Wednesday, April 4th at the Derry Municipal Center so that neighborhood residents may stop by and learn more about the upcoming work. Currently, the nearly half-acre site includes a concrete slab where the dry-cleaning business once operated, a paved parking area, and undeveloped land.

Joint investigations conducted by EPA and NHDES revealed elevated levels of a by-product of the dry cleaning process called PCE in the soil on the property. Investigations also revealed that the groundwater beneath the property has shows signs of PCE contamination. PCE is also known as tetrachloroethylene and perchloroethylene, and was used at the site from approximately 1984 through 2001. Prior to 1984, dry-cleaning was performed using petroleum hydrocarbon based cleaners.

PCE-contaminated soil on the property is an ongoing source of contamination to the groundwater and may also be a potential source of vapor intrusion to nearby buildings. Once in the groundwater, vapors migrate through the soil and along underground utility lines or drains and may seep through cracks in basements or foundations. Vapor intrusion is a concern because vapors can build up to a point where the health of residents or workers in an affected building could be at risk.

Over the next several weeks, EPA and NHDES crews will secure the site; conduct additional sampling to determine the full extent of contaminated surface and sub-surface soils on the site; excavate and ship the contaminated soil off-site for disposal at an approved facility; and cap any contaminated soil which may remain at depth.

Once excavation work is completed, the excavated areas will be backfilled with clean fill and graded. Also, EPA and NHDES will work together to investigate whether potential indoor air / vapor intrusion problems exist at nearby properties and whether they are due to contamination from the site. EPA has allocated $870,000 to the project which is expected to take three months to complete.