Friday, 15 January 2010 00:00
The New York State Department of Environmental Conservation (DEC), in conjunction with the State Department of Health (DOH) and representatives from National Grid, will hold a public meeting on Wednesday, Jan. 20, at 7 p.m., to present the findings of the final cleanup investigation report for the Glen Cove former Manufactured Gas Plant (MGP) site in Glen Cove, Nassau County.
The meeting will be held at Gribbin Elementary School located on Seaman and Walnut Roads in Glen Cove. At the meeting, DEC, DOH and National Grid staff will describe the contents of the final report, present a cleanup action plan to address contamination found at the site, and respond to questions and comments from the community. Key findings in the report and cleanup plan include:
• There are no significant imminent hazards to human health. The site is securely fenced and there are no domestic or public water supply wells located within one half mile of the site. Safety precautions, however, must be taken during any excavation operations to protect workers and residents from exposure.
• The site’s main contaminant is MGP tar, a dark oily liquid that is denser than water and very persistent in the environment. The MGP tar acts as a source for soil and groundwater contamination.
• Tar-contaminated soil was found over a relatively compact area beneath the area of former MGP operations. Some of the tar has moved through subsurface soils to the north and west, just beyond the northern site limits.
• Most of the tar contamination resulted from underground leakage from pipes and tanks on the site, therefore the heaviest contamination is found below the ground surface where human contact is unlikely. Tar impacts generally begin at or just above the water table. The degree of contamination decreases at lower depths. The deepest impacts were found approximately 45 feet below the ground surface. Some chemical impacts were found in surface soils; however, this appears to have resulted from unrelated activities on the site after the MGP ceased operations.
• Soil vapor samples were collected on properties next to the site to evaluate the potential for vapors associated with the site contamination to enter into nearby structures. The survey did not detect site-related chemicals at levels of concern. Therefore, no further investigation regarding off-site soil vapor is warranted.
• The investigation determined that the site presents minimal potential risk to the wildlife on or near the site due to the location of the contamination under the ground surface, and the industrial use of the property.
There is an active LIPA electrical substation on the former MGP site that greatly limits potential exposure to site-related contamination. However, this substation also limits the ability to excavate and remove the contaminated subsurface soils. Accordingly, the draft cleanup plan (called a draft Remedial Action Plan) includes:
• Removal of accessible contaminated soils (outside the LIPA substation) for off-site thermal treatment and/or disposal.
• Installation of an oxygen injection system to treat contaminated groundwater. These systems have proven effective at other MGP sites, limiting the potential for the contaminated groundwater to migrate into off-site areas.
• Installation of tar recovery wells to collect mobile tar that remains underground. Tar which moves into these wells will be removed on a periodic basis, and will be shipped off-site for proper treatment and disposal.
• Long-term groundwater monitoring to assess the effectiveness of the cleanup actions undertaken at the site.
• A “Site Management Plan” (SMP) will be implemented, including provisions to ensure that any future excavation or redevelopment work on the site does not lead to human exposures, and does not release site-related contamination into the environment. The SMP will include a soil-management plan to govern handling and treatment of excavated soils, a monitoring plan to ensure that the cleanup work remains effective over time, and an operations and maintenance plan for the groundwater oxygen injection system.
The Glen Cove MGP site located in the Glen Cove Brownfields Opportunity Area is near the intersection of Grove and Stanco Streets. It is bounded to the north by the Long Island Rail Road (LIRR) tracks, to south by Grove Street, to the west by Route 107 and Glen Cove Creek, and to the east by residential properties. An active Long Island Power Authority (LIPA) electrical substation currently occupies a large portion of the site.
A small manufactured gas plant (MGP) operated on the site from 1904 until 1923, providing gas to customers in Sea Cliff, Glen Cove and the Town of Oyster Bay. This plant heated coal and petroleum products to produce a flammable gas mixture which was used for heating, cooking, and lighting purposes in much the same way that natural gas is used today. The Long Island Lighting Company (LILCO) acquired the plant in 1923, and connected the local gas distribution pipes to other, larger plants in other areas. Operations at Glen Cove ceased shortly afterwards, and the plant was demolished in 1929. Some soils beneath the plant site had been contaminated during the operation of the plant, and these soils were left in place, where they remain today.
Currently, the eastern portion of the site is occupied by an operating, fenced electrical substation that is owned by the Long Island Power Authority (LIPA) and operated under contract by National Grid. National Grid personnel periodically check the status of the substation and conduct routine maintenance and operating activities. National Grid is the party responsible for the investigation and cleanup of the site because a predecessor company operated the MGP.
Copies of site documents are available at the Glen Cove Library located at 4 Glen Cove Avenue, Glen Cove, and at DEC’s Long Island regional office at 50 Circle Road, Stony Brook. Comments and questions are always welcome and should be directed to Amen Omorogbe, DEC Project Manager, 625 Broadway, Albany, NY 12233-7014, (518) 402-9564, or Jacquelyn Nealon, DOH Project Manager, 547 River St., Room 300, Troy, NY 12180-2216, (800) 458-1158 ext. 27870. National Grid has a hotline for neighbors of the site. The hotline provides an opportunity to ask questions or leave comments, (516) 545-3589.
For more information on DEC’s Manufactured Gas Plant cleanup program, visit our website at: http://www.dec.ny.gov/ chemical/8430.html. DEC released on update on progress made at former MGP plants on Long Island and in New York City in 2008: http://www.dec.ny.gov/ press/47736.html.
For additional information about site activities and other related information about the site, please visit National Grid’s website for the project at: www.glencovemgpsite.com.