SLEEPY HOLLOW, N.Y. Environmental officials have devised and released a draft clean-up plan for the former General Motors site in Sleepy Hollow that proposes to cover over-polluted soil on-site and remove contaminated soil in the Hudson River.
A public meeting on the remedial investigation and proposed clean-up will be held March 22 at 7 p.m. at the James Galgano Senior Center in Sleepy Hollow.
It is estimated that activities to clean up the site will take up to two years for sediments, whereas the land-based engineering and institutional controls will be integrated with design and redevelopment of the site over several years, the Department of Environmental Conservation said in a fact sheet. NYSDEC will keep the public informed during the cleanup of the site.
The 97-acre property, where General Motors assembled cars and vans until the plant closed in 1996, is poised for development. A developer has not yet been chosen, but previous plans have included upscale housing, shopping and a hotel/conference space. Nothing can be built, however, until remediation is complete.
The Department of Environmental Conservation had previously approved a series of interim remedial measures that would take place before and during site development in July 2007. Officials have already removed about 14,900 cubic yards of grossly contaminated soil containing lead, chromium, trichloroethene and petroleum. Chemical oxidants have also been used to treat residential groundwater.
Officials said in a recently-released fact sheet that an investigation conducted in consultation with the New York State Department of Health found the site does not pose a significant threat.
Soil cleanup objectives for the protection of groundwater have not been applied, officials said, because the groundwater is not migrating off-site and the groundwater is not suitable for development as a water supply.
Proposed remedies include providing a cover system of at least a minimum of two feet of soil where grasses and other plants are desired. Hard, protected surfaces including building slabs and pavements will also be used to prevent contact with soils and historic fill that does not meet the soil clean-up objectives.
Future building designs will be required to incorporate measures that eliminate the possibility of natural soil and chemical gasses or vapors to enter an indoor air space, according to the DEC. Construction crews will be restricted from handling the soil or excavating beneath the soil cover. Future property owners will also be required to follow specific rules when working with the polluted soil.
Officials are also proposing the removal of off-site, contaminated Hudson River sediments that have been polluted with high concentrations of metals such as chromium, copper, lead, mercury and zinc. The proposed action would affect about 4,400 cubic yards of the river bottom about 150 feet north and south of an existing storm water outfall.
Dredging would take place as deep as 10 to 17.5 feet below the mean sea level during the proposed soil removal, the DEC said. The contaminated soil would be disposed of at an off-site waste management facility or recycled for on-site use as fill beneath the proposed cover system if environmental officials approve it.
The draft plan can be found online or in hard copy at Warner Library and Sleepy Hollow Village Hall.
Citizens will have the opportunity to comment on the proposed action until March 30. Comments can be sent to Project Manager Jason Pelton at firstname.lastname@example.org or Jason Pelton, NYSEC project manager, New York State Department of Environmental Conservation, Division of Environmental Remediation, 12th Floor, 625 Broadway, Albany, N.Y. 12233-7017.