Written by Carol Frank Friday, 08 March 2013 00:00
Plans to expand and upgrade the mitigation of decades old contamination at sites along Great Neck Road were explained at a public meeting on Feb. 25 which was conducted by a bevy of NYS Department of Environmental Conservation (DEC) representatives and one official from the New York State Department of Health (DOH) along, with the engineer for the property owner. There were only three members of the public present, Gregory Graziano, superintendent of the Water Authority of Great Neck North; Stephen Moriarty, WAGNN assistant superintendent and this reporter.
The history of this state superfund site goes back to 1992 when inspectors for the DOH inspected and sampled two dry wells in the basement of the Mayflower Cleaners at 471-491 Great Neck Road. The operator of the establishment admitted to draining boiler water into the dry wells each day. When the soil was tested for chemicals, it was found that tetrachloroethylene (PCE) was present at levels between 3.4 parts per million (ppm) and 2.4 ppm, both findings which were above the allowable levels according to Environmental Protection Agency and DEC standards of 1.4 ppm.
PCE is a colorless organic liquid with a mild, chloroform-like odor which has been implicated in liver disorders and cancers. Due to concerns about its potential health dangers, it fell under government regulations in 1992.
What Has Been Done So Far To Protect the Public?
There are three ways that this substance can enter the human body. First, there is direct contact with PCE which is highly unlikely in this case. Second, it can enter the body through inhalation going from the lungs into the bloodstream. Third, it can enter the body through ingestion.
The DEC and the health department officials are more concerned in this case with soil vapors from the contamination. The owner of the property, Plymouth Realty Corporation, hired engineers to design and install a barrier to keep the vapors from entering the air in the dry cleaning establishment and the adjacent bagel store in 2010.
Due to results from additional testing required by the governmental agencies, it is now being recommended that the owner expand the barrier to include the mini-mall located just north of Mayflower Cleaners. In addition, the upgrade will include the installation of a blower motor and the connection of an additional suction pit and piping in the mini-mall to protect the air quality. John Sheehan, the project manager from the DEC said that the air quality testings performed do not indicate a need to worry about the Lakeville Branch of the Great Neck Library, the pet store and the liquor store located just north of the mini-mall.
The barrier that is used for such remediation projects is a sub-slab depressurization system that creates a vacuum that prevents the vapors from escaping. It is estimated that the entire system will cost the owner $150,000.
Keith Brodock from the engineering firm Integral Consulting, Inc. who works for the site owner explained that the sub-slab system does not eliminate the PCEs, but does a good job of containing them so that they do not pollute the air.
Many questions were raised about the testing that was done to determine if PCEs have traveled downward from this site into the aquifer system that provides drinking water for the peninsula. The water samples to determine the extent of the contamination were taken at a depth of 10 feet. Typical wells that are used for drinking water are drilled at a depth of 135 to 140 feet for the Magothy aquifer and 396 feet for the Lloyd aquifer.
It is important to note that the Water Authority of Great Neck North tests for PCEs as well as a host of other chemicals in all their numerous monitoring wells and their 10 pumping wells on a monthly basis.
While the state allows 1.4 ppm of PCE in drinking water, the Authority cleans the water until no PCEs are present, a standard called “non-detect.”
According to Mr. Graziano, the authority has found PCEs in certain wells in the area, but that contamination has been attributed to another superfund site, Stanton Cleaners on Cuttermill Road, which has been a target for clean-up for many years. The necessary treatment is already in place to make sure that all drinking water impacted by the Stanton site is safe to drink and exceeds state and federal requirements.
It is the responsibility of the authority to be ever vigilant regarding new sources of contamination, because cleaning water to drinking level standards is very expensive and if the responsible party is found and held accountable, they share in the burden of costs for clean-up.
Mr. Graziano, on behalf of the Authority, is formally requesting the DEC and the DOH require that the responsible party in the Mayflower case take more water samples at greater depths to insure that the contaminants have not perked downward into the Magothy and Lloyd aquifers.
The period for public comment runs through March 20, 2013.