The U.S. Navy is updating a plan to remove soil contamination on a former drum storage site in Bethpage that contains abandoned cesspools, tanks and more relics from defense department activities dating back decades.
The revised cleanup — prompted by the discovery of higher concentrations of a banned chemical used in electrical and industrial applications — also includes plans to increase treatment of soil vapors so that air quality is not affected in the area near industrial and residential neighborhoods.
Costs for the Navy’s preferred cleanup plan are estimated to be at least $30 million and could take as long as 30 years to complete.
State Department of Environmental Conservation officials must approve the plan. If that happens, remediation could begin in 2018.
The initial remediation plan was part of a 1995 agreement with the state that included other, higher-priority cleanup sites. At the time, officials thought the primary contamination would be from volatile organic chemicals, such as the solvent and carcinogen trichloroethylene, but recent investigations found polychlorinated biphenyls, or PCBs, to be the main concern, said Lora Fly, a remedial project manager for the Naval Facilities Engineering Command.
“We found out there was more PCBs than we initially thought,” she said, adding, “The remedy was not applicable.”
Manufacturing of PCBs ended in 1977, but the man-made probable carcinogen does not easily break down in nature and can be found in air, water and soil, according to U.S. Environmental Protection Agency.
The 4.5-acre site west of 11th Street has 120 abandoned cesspools, six aboveground storage tanks that once held waste oils, four sludge-drying beds, two dry wells used for storm water runoff and two underground storage tanks that once stored tetrachloroethene, a likely carcinogen.
From the 1930s to mid-1990s, the Navy and what is now Northrop Grumman occupied more than 600 acres in Bethpage to research, test and manufacture airplanes and space-exploration vehicles. Contaminated water was first discovered in the 1940s and the site was added to the state Superfund list in 1983. The updated cleanup is one of several efforts underway to remove contaminated soils and a number of groundwater plumes, one of which has migrated 3 miles from the site.
The site under review now is adjacent to a plant where World War II-era aircraft were assembled, said David Brayack, a Navy consultant with the engineering and consulting firm Tetra Tech, headquartered in California.
Concentrations of PCBs were detected to be above 50,000 parts per billion in some areas, he said during a November meeting with residents in Bethpage about the site. That concentration is twice what is generally allowed in soils 2 feet beneath the surface at remediated industrial sites, according to the state Department of Environmental Conservation.
“This is more a redefinition of the extent of soil contamination,” said Martin Brand, remediation and materials management deputy commissioner for the DEC, which is overseeing the cleanup.
Three storage sheds have been removed and the site is vacant with some paved areas, but starting in the 1950s the Navy used it to store hundreds of drums of waste containing chlorinated and non-chlorinated solvents, liquid cadmium and chromium, according to the Navy. Transformers potentially containing PCBs and other equipment were stored there in the 1990s, according to the Navy.
New research has shown that PCBs have contaminated an estimated 130,000 cubic yards of soil, from 2 to 65 feet below the surface, as well as about 14,000 cubic yards of material from the dry wells. The metals arsenic, cadmium and chromium are also present and will be removed.
Soil vapor containment systems designed to prevent contaminants getting into the air were installed in 2010 along the eastern and southern perimeters of the site and will continue to run. Up to six more will be installed in more central parts of the site, Brayack said.
Air quality will also be monitored in the adjacent neighborhood, Fly said.
INFORMATION AND COMMENTS
The plan can be found at go.usa.gov/DyXF or the Bethpage Public Library, 47 Powell Rd. in Bethpage.
Comments on the plan will be accepted through Jan. 22 and can be mailed to Public Affairs Officer, Code 09PA, Naval Facilities Engineering Command Mid-Atlantic, 9324 Virginia Ave., Rm. 302, Norfolk, VA 23511.