The New York State Department of Environmental Conservation (DEC) will hold a public meeting to discuss DEC's proposed remediation of the American Drive-In Cleaners Inactive Hazardous Waste Disposal Site, on Monday, June 17 at 7:30 p.m., at the Island Trees High School, 59 Straight Lane.

The American Drive-In Cleaners site consists of approximately 0.37 acres and is located at 3801 Hempstead Turnpike in Levittown. A dry-cleaner, which closed in 2001, apparently disposed of perchloroethylene, or "perc," a common dry-cleaning chemical at the site.

This disposal resulted in the contamination of soil and groundwater by hazardous waste (PCE). DEC designated the American Drive-In Cleaners Site as a Class 2 inactive hazardous waste disposal site and conducted a remedial investigation to determine the nature and extent of the contamination. A Class 2 site is one which presents a threat to public health or the environment and requires investigatory or remedial action.

A remedial investigation conducted by DEC included soil, groundwater and air sampling, an evaluation to determine the extent of the contamination, and identification of risks to human health and the environment if the site were left unremediated. In January 2001 DEC split the site into two operable units. Operable Unit 1 (OU1) consists of the affected area north of Hempstead Turnpike, and Operable Unit 2 (OU2) consists of the affected area beneath and south of Hempstead Turnpike. The remedy of in situ chemical oxidation, soil vapor extraction, onsite groundwater extraction and treatment, and long term groundwater monitoring was selected for OU1 in a March 2001 record of decision. DEC split the site into two units to allow remediation of the onsite source areas and contaminated groundwater to proceed while necessary additional data were being gathered concerning the off-site groundwater plume. DEC is currently negotiating implementation of the onsite cleanup with the property owner.

The investigation showed that groundwater was the only medium within OU2 to be affected by the contamination. PCE was present in 34 of 61 groundwater samples taken from offsite monitoring wells. Water samples taken from an irrigation well on the Island Trees High School property had concentrations of PCE at up to 21 ppb. The groundwater standard for PCE is five ppb. Trichloroethene and dichloroethene were also present in OU2 groundwater.

DEC is proposing in situ air sparging, soil vapor extraction, and long term groundwater monitoring. Under this remedy groundwater would be treated in place via air sparging. The air sparging system would consist of approximately 125 sparge wells, installed to a depth of 50 to 80 feet, or 15 to 45 feet below the water table. Air would be injected into the groundwater through these wells. Contaminants such as PCE will evaporate into the air as it rises through the groundwater. A soil vapor extraction system would capture the air once it rose above the water table.

The soil vapor extraction system would consist of approximately 30 vertical vapor extraction wells. These wells would be connected by pipes to a treatment building where a vacuum would be applied to the system to draw contaminated air from the subsurface soils. The contaminants in the extracted air would be treated with activated carbon before release to the atmosphere. DEC expects this system to remove close to 97 percent of the mass of contaminants above groundwater standards over about ten years.

DEC's proposed remedy would include a long-term groundwater monitoring plan and a contingency plan to install a new irrigation well on the Island Trees High School property if monitoring of the current irrigation well indicates that PCE concentrations in the well exceed acceptable limits.

DEC's preferred remedy is described in a proposed remedial action plan for the American Drive-In Cleaners Inactive Hazardous Waste Disposal Site, Operable Unit 2.

At the June 17 meeting, DEC and State Department of Health staff will review the history of the site, and describe the results of investigations completed to date and the proposed remedial action plan. Meeting participants will be given the opportunity to ask questions and provide comments on the proposed remedial action plan. Written comments may also be submitted to Robert Filkins, Project Manager, NYSDEC, 625 Broadway, Albany, NY 12233-7015. The comments must be submitted by July 8.

Based upon the public comments received, DEC may modify its proposal or select a different course of action. Written responses to all substantive comments received will be published by DEC as part of the record of decision for the site. The record of decision, a report that describes the final remedial plan for the site, will be placed in the document repositories and the public will be notified when the record of decision is available in these repositories.

Site documents, including the proposed remedial action plan and the remedial investigation reports, are available at DEC's Stony Brook headquarters and the Island Trees Public Library. Site information is also available at www.dec.state.ny.us/website/reg1/hazwaste.html.