The Department of Environmental Conservation (DEC) held a meeting recently in Great Neck to discuss the progress of the Lockheed Martin cleanup to stop the contaminated plume from traveling further north.

At the outset of the meeting it was clearly stated that the main topic of the discussion was to focus on the remedial action and development of plans for Operable Unit-2 (OU-2) offsite interim remedial measures. The majority of the audience consisted of Great Neck residents. The only resident from New Hyde Park was Michael Curry who has been extremely active in the cleanup process since it began.

Once again, as he has in the past, at the end of the meeting, Curry inquired about Operable Unit -1. (OU-1) He wanted to know whether the wells to the south of the project have been tested to see if the plume has not only moved to the north, but also moved to the south. He was told they had not been tested because since the cleanup of the OU-1 site has begun, on the property of the former Lockheed property, any contamination that has migrated south of the site will now travel northwest and be captured by the new OU-1 treatment system.

It was explained that the groundwater plume traveled a few hundred feet to the south of the property line, due to the historical use of the onsite diffusion wells located on the south side of the site. No further southward migration is expected because the use of the onsite diffusion wells was discontinued in the summer of 2001. The treated water from the OU-1 groundwater system is now discharged through offsite diffusion wells located northeast of the site along the Northern State Parkway.

Curry said that years ago he requested that more monitoring wells be installed around the site including several to the south, but that was never done. He said he was in full support of the project to make sure the OU-2 site was cleaned up but he said he wanted to make sure all the wells are tested for the safety of everyone in the vicinity of the former Lockheed Martin property.

Written comments on this project will be accepted through Jan. 21 by contacting Girish Desai, project manager NYSDEC, SUNY Building No. 40, Stony Brook, New York, 11780-2356. Draft of the work plan for the project will be available at both the Hillside Library, Hillside Avenue and the Parkville Branch Library, 10 Campbell Street, both in New Hyde Park.

The meeting was the last before the Great Neck School Board was to make a decision on whether or not they would give permission for an extraction well to be installed in the area of the Great Neck School District maintenance yard. When the DEC met with the Great Neck Board of Education they also requested permission to install pipelines necessary to carry contaminated water from the extraction well to a treatment plant and to then carry the clean water from the treatment plant to reinjection wells proposed to be located on Department of Transportation property along the Long Island Expressway immediately east of the school district's property.

The plan, as it stands now, is to pump water from the well to a air stripper well owned by the Manhasset Lakeville Water District. The treatment plant will be leased from the Manhasset Lakeville Water District. Putting the treatment plant at the existing MLWD facility will allow Lockheed Martin to use the treatment system already in place to treat contaminated water in the OU-2 well. The IRM (Interim Remedial Measure) is a discrete action that can be taken without extensive investigation to remove or isolate a source of contamination. It has also become apparent that VOCs (volatile organic compounds) north of the Lockheed site threaten public supply wells and the North Hills Special Groundwater Protection Area (SGPA).

The DEC has directed Lockheed Martin to implement two interim remedial measures to protect the drinking water resources and the SGPA from further contamination from the groundwater plume. One of these systems will be located south of the Long Island Expressway. Construction of the system is the highest priority to DEC and will be DEC's immediate focus. A second IRM will be located north of the Long Island Expressway and is in the planning stages Lockheed Martin has also applied to the New York State Department of Transportation to install the proposed reinjection wells.

The use of the Manhasset Lakeville well also ensures the shortest possible route by which groundwater extracted by a well in the Great Neck School district maintenance yard would be transported for treatment and minimizes the construction necessary to provide an efficient and protective treatment system. It would also reduce the time required to design and construct the IRM.

At this time the contaimination is approximately 200 feet below land surface under the school district property. It is about 150 feet from land surface to groundwater. There is then a layer of approximately 60 feet of clean water above the contaminated groundwater. This layer of clean water and the distance between the dissolved contamination and the land surface ensures that no contamination vapors can make their way to the surface where humans could be exposed.

The proposed extraction well on the school district property would present no exposure to the students, faculty, staff or community. The well would be a vault completely below ground. The only ground surface indication of the well would be a small concrete pad with a manhole cover that will be locked.

The extraction well will not release vapors to the air. The treatment facility will not be located on school property and the pipes carrying the exracted water will be underground. Contaminated groundwater will be piped directly from the extraction well to the treatment plant in double walled pipes. The double walled pipes will be equipped with leak detection systems. In the unlikely event of a pipe rupture, the extracted groundwater will be contained by the outer wall and the extraction well will be shut down by the leak detection system.

As a further precaution, the entire system will be equipped with a second system to detect a decrease in water pressure. A pressure decrease, as would occur with a leak, will cause the system to shut down automatically. Even if both automatic shutdown systems failed simultaneously it is unlikely that a leak would result in direct exposure to contaminate water as the pipeline will be found to five feet below the ground surface. However, even transient direct exposure to water with the current levels of contamination would not be a cause for human health concern.

Lockheed Martin proposes to use a portion of an existing single-walled pipeline to move treated water from the treatment plant to the reinjection wells. The pipeline had been used to carry water from public supply wells north of the Long Island Expressway to the MLWD Parkway Station treatment plant. It is designed to carry 1,000 gallons per minute. However, it would only be used to carry 500 gallons per minute in the proposed treatment. The single-walled pipeline would present no more risk than any public water supply main.

Lockheed Martin proposes to remove VOCs from the contaminated groundwater by using either of two existing air strippers at the MLWD Parkway Station facility. The air strippers would be designed to remove approximately 99.6 percent of the VOC contamination, leaving undetectable levels of contaminants in the water to be returned to the aquifer.

After a review of the public comments and assuming approval by the Great Neck School District, the DEC expects to approve a final work plan. Once that is done, Lockheed Martin will obtain access agreements, permits, finalize design of the facilities and begin installation of the extraction well and pipelines.