Fears of Schenectady County’s water supply being compromised were recently lifted after a seven-year battle to mitigate a groundwater plume containing trichloroethylene.
The General Services Administration, the federal government’s landlord, has signed a Federal Facility Site Remediation agreement with the New York State Department of Environmental Conservation. The agreement positions the GSA to move forward with clean-up plans at the former Navy Depot. The agreement places responsibility on the federal agency for cleaning up the environmental issues caused when the Scotia Navy Depot in Glenville was in operation. After the Vietnam War, most Navy functions at the site ceased.
“They used to maintain and repair trucks there during the Vietnam War … and that is probably how it got there. It was critical for the county to safeguard our multi-billion gallon aquifer,” said Ray Gillen, commissioner of Economic Development and Planning for the county. “Job one was protecting the environment and getting the Depot cleaned up. The next step is trying to redevelop the parcel for new jobs and new tax base.”
The chemical trichloroethylene, or TCE, has been identified at a depth of 70 feet below the surface at the site, according to county officials. The plume, according to DEC tests, is within a portion of the Great Flats Aquifer Protection Zone and is headed toward the Mohawk River. The aquifer is the underground water supply providing drinking water to almost all Schenectady County residents. Often, TCE is used in solvents for industrial purposes as a degreaser.
“The TCE plume must be stopped and the federal government has finally owned up to its responsibility to fix the environmental damage caused by the former Navy operation,” said County Legislator Cathy Gatta, D-Scotia, in a statement. “This is a great day for residents of Glenville who want to see this property cleaned up and put back on the tax rolls.”
In March 2010, the GSA agreed to a DEC Record of Decision outlining the environmental problem and a plan to fix it. _County officials said they’ve kept pressing federal and state officials to get an agreement signed. Also, county officials identified clean up of the Depot as a priority for its unified economic development team back in 2004.
In order to clean up the area, the GSA will install a zero valent iron permeable reactive barrier beneath the surface of the affected area, which is estimated to cost around $3 to $4 million. This type of barrier has been successfully implemented before to stop TCE plumes and break down the chemical to eliminate any health threats, according to county officials. The barrier will be injected into target areas through a series of soil borings.
Rick Georgeson, spokesman for DEC Region 4, said the depth of the aquifer varies considerably ranging from 10 feet to over 100 feet. The average thickness is typically 50 to 70 feet. The aquifer covers a very large area in the Mohawk Valley from just west of Rotterdam Junction to just east of the City of Schenectady, where the Alplaus Kill flows into the Mohawk, he said.
“There is contamination in the aquifer at the Navy Depot site. Fortunately this part of the aquifer is not the most productive in terms of producing water and it is not used as a water supply,” Georgeson said in an email. “The barrier is not a ‘barrier’ to groundwater flow, but a ‘barrier’ to the contaminants present in the water. As contaminated groundwater flows through this iron treatment zone (barrier) it contacts the zero valent iron and through a chemical reaction the contaminants are broken down to nontoxic end products.”
Gillen said work is expected to start before the beginning of next year, and since the depth of the soil work is not extreme the project can be conducted year-round.