CX/ACC	EPA REGION 2
SYOSScT	CONGRESSIONAL DIST. 03
_ _ _ _ __ _ _ _ _	o Nassau County
LANDFILL	m °*s,erBa'
NEW YORK
EPA ID# NYD000511360
Site Description 	
The Syosset Landfill Site is located in the Town of Oyster Bay, Nassau County, NY. The site is
approximately 38 acres in size. Single family residences and an elementary school are located to the
northeast of the site. Offices and storage yards for the Town of Oyster Bay Sanitation and Highway
Departments occupy the southern end of the site. The Landfill operated from approximately 1933 to
1975. Between 1933 and 1967, no restrictions were imposed on the types of wastes accepted at the
landfill. Waste types included: commercial, industrial, residential, demolition, agricultural, sludge
material and ash. In 1967, with the opening of another landfill to the east of Syosset in Old
Bethpage, the Town stopped using the Landfill for the disposal of its domestically generated wastes.
The Town also directed some industrial generators to use the Old Bethpage facility, but some
industrial wastes continued to be disposed of at the Landfill until it was closed.
„ ...... ^ . . . , . ,, , , ,	NPL LISTING HISTORY
bite Responsibility: This site is being addressed through	Proposed Date- 12/01/82
Federal and potentially responsible	Final Date: 09/01/83
parties' actions.
Threats and Contaminants 	
Groundwater contains low levels of volatile organic compounds (VOCs) including vinyl
chloride, benzene, toluene, and xylene; heavy metals including lead, arsenic, chromium,
cadmium, manganese, and iron; and polychlorinated biphenyls (PCBs). Accidental
ingestion and direct contact with contaminated groundwater were potential health threats
for individuals living near the site. However, with the construction of the site remedy
completed, all potential health threats have been eliminated.
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Cleanup Approach
The site was addressed in two stages: immediate actions and a long-term remedial phase
focusing on cleanup of the on-site contamination.
Response Action Status 	
Immediate Actions: A permanent ventilation trench has been constructed
to prevent gas migration from the site to the school area. Continuing air
analysis indicates that the gas concentrations in the area north of the
ventilation trench were reduced to non-detectable levels.
On-Site Contamination: The potentially responsible party completed an
investigation to determine the extent and nature of on-site contamination. The
EPA selected a remedy in 1990, which includes capping the landfill,
monitoring and maintaining the gas collection system, installing an additional gas venting
system, monitoring the air and groundwater quality, maintaining the fence around the
perimeter of the landfill, and implementing institutional controls to restrict future use of
the landfill. The design of the remedy began in October 1991 and included the
placement of clean fill material on site in order to enhance settlement prior to cap
construction (which is known as a pre-load program). This pre-load program was
completed in May 1996. The final design for capping of the landfill was approved in
May 1996. The capping of the Landfill was completed in November 1997.
Approximately 6,732,000 tons of contaminated material were contained. The second
operable unit ROD signed March 28, 1996, selected no action for the groundwater.
[N Off-Site Contamination: The possible migration of contaminants from
the landfill was investigated. The field work to determine the extent of off-site
groundwater contamination was initiated in September 1992 and was
completed in September 1993. EPA determined that contamination was limited and did
not pose a significant threat to human health or the environment and therefore, no
groundwater remediation was necessary. This determination was documented in a
Record of Decision which EPA issued on March 28, 1996.
Cleanup Progress
The threat of gas vapor migration from the landfill has been eliminated. In October 1996,
the installation of the cap was completed and approximately 6,732,000 tons of waste were
contained. The capping of the landfill has eliminated the potential of a direct contact
threat and will control leachate generation associated with rainfall infiltration. On
September 18, 1998, EPA determined that all construction activities were completed at
the site.

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Site Repository
Oyster Bay Town Hall, 54 Audrey Avenue, Oyster Bay, New York, 11771
Syosset Public Library, South Oyster Bay Road, Syosset, New York, 11791
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