(Initial distribution: May 1997)
What is the Action Memorandum?
The Action Memorandum for Operable Unit III Groundwater Removal Action documents the decision by the U.S. Department of Energy to conduct an interim removal action for groundwater contaminants within Operable Unit III at Brookhaven National Laboratory.
This action is being taken in response to a plume of volatile organic compounds detected in on- and off-site groundwater during the Operable Unit III remedial investigation. The removal action is being carried out prior to the completion of the remedial investigation to prevent further migration of contaminated groundwater into areas south of the site boundary. The contaminants are from multiple unidentified sources (still under investigation) in the developed central portion of the Lab site.
What is the proposed action?
The action memorandum also documents the installation of a pump-and-treat system at the Lab's south boundary. Six extraction wells will pump a total of 600-700 gallons of water per minute from the aquifer and pipe it to a treatment facility, where the volatile organic compounds will be separated out. The clean water will be released to a recharge basin located approximately one mile north of the site's southern boundary, and the volatile organic compounds will be released into the air at levels that meet state guidelines. An air equivalancy permit is being obtained from the New York State Department of Environmental Conservation for this action.
The system will be sampled regularly in accordance with state permit requirements. All monitoring is overseen by the Department of Energy, the U.S. Environmental Protection Agency and the Department of Environmental Conservation.
What was found?
During the remedial investigation process, it was found that volatile organic compounds in groundwater had migrated off-site beyond BNL's southern boundary at levels above drinking water standards. The primary contaminants found in this plume are tetrachloroethene (PCE), trichloroethane (TCA) and carbon tetrachloride. The PCE and TCA are primary contaminants in the plume on-site. Carbon tetrachloride is more prevalent in the off-site portion of the plume. Additional groundwater monitoring is being performed to further define the extent of the contamination both on- and off-site.
The Operable Unit III Remedial Investigation/Risk Assessment Report will document detailed information concerning the potential release of contaminants into the environment. This document is expected to be available in winter 1997-98 and can be found at the libraries listed below (for locations click here).
Although current data and modeling show that this contamination is located at depths generally below residential wells, public water has been offered to the potentially affected communities south of the BNL site boundary.
Public water has been offered to property owners in an area bounded by River Road to the west; Colin Drive, Moriches-Middle Island Road and Carleton Drive to the north; Sleepy Hollow Drive and Cranford Boulevard to the east; and Sunrise Highway to the south. This action was taken as a precautionary measure to prevent any potential future exposure to groundwater contaminants associated with Operable Unit III.
What is the time frame?
The pump-and-treat system is due to begin operation in June 1997. While the system is expected to operate for several years, an estimated operating period will be set in the Operable Unit III Feasibility Study, due out in spring 1998.
The Action Memorandum and a supporting document known as the "Operable Unit III Pre-Design Investigation Report" are available at the libraries listed below. The Pre-Design Report documents the basis and procedures used in identifying, developing, and evaluating groundwater remediation alternatives.
General background
Operable Unit III is the administrative name given to about 2,100 acres of Brookhaven National Laboratory's central and western area.
BNL is a U.S. Department of Energy laboratory that was placed on the New York State Department of Environmental Conservation's "Inactive Hazardous Waste Disposal Sites" list in 1980. In 1989, BNL was included on the U.S. Environmental Protection Agency's "National Priorities List" for cleanup. BNL was placed on these lists because of the environmental effects of past practices, some of which could pose a threat to Long Island's sole source aquifer.