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Region 2 Superfund

Serving New Jersey, New York, Puerto Rico, US Virgin Islands and Eight Tribal Nations.

Onondaga Lake Superfund Site
Onondaga County, New York

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Larisa Romanowski: (518) 747-4389

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Lower Ley Creek Subsite of Onondaga Lake Site Record of Decision [18 MB, 387 pp]

Public Notice: Five-Year Review for LCP Bridge Street Subsite [6.7 MB, 27 pp]

Lower Ley Creek Proposed Plan [6.7 MB, 27 pp]

Supplemental Human Health Risk Evaluation, Lakeview Amphitheater Facility

Onondaga Lake is a 4.5 square mile lake located in the City of Syracuse, the Towns of Salina, Geddes, and Camillus. The lake drains approximately 285 square miles of the surrounding areas. Because of extensive pollution, the lake was proposed to the NPL on May 10, 1993, and officially listed on December 16, 1994. The Onondaga Lake superfund site consists of the lake itself, seven major and minor tributaries, and upland sources of contamination to the site (called subsites), of which there are eleven. The lake flows into the Seneca River, then into the Oswego River and ultimately Lake Ontario.

The availability of salt and limestone along Onondaga Lake led to the Solvay Process Company, later Allied Chemical, and now known as Honeywell International, Inc., to locate along the west side of the lake. In 1946, Allied Chemical initiated a mercury cell process which resulted in waste streams containing mercury and heavy metals being discharged by its facilities at Willis Avenue and Bridge Street. Honeywell’s Semet Residue Ponds are another source of contamination to the lake. The primary Potentially Responsible Party (PRP) for the site is Honeywell. The site is being addressed through federal, state, and PRP actions. New York State is the lead agency on this cleanup.

Historically, industrial processing at Solvay Processing/AlliedSignal/Honeywell Inc., and municipal wastewater treatment plants routinely discharged their wastes into the lake. As a result, surface water is contaminated with mercury, and sediments are contaminated with polychlorinated biphenyls (PCBs); pesticides; creosotes; heavy metals including lead, cobalt, and mercury; polycyclic aromatic hydrocarbons (PAHs); and volatile organic compounds (VOCs) such as chlorobenzene. Ground water at many of the upland subsites is also contaminated. Several species of fish native to the lake have high concentrations of mercury. Public fishing in Onondaga Lake was banned in 1970, but the lake was opened for catch-and-release fishing in 1986. Contact with or ingestion of contaminated groundwater, surface water, or sediments could pose a health threat, although EPA and New York State have determined that the site poses no immediate threat to human health or the environment while studies are being performed.

The Onondaga Lake Superfund cleanup is being addressed in two stages: 1) interim remedial measures (IRMs) and 2) long-term remedial actions focusing on cleanup of the subsites. IRMs undertaken at the site include: removing chlorobenzene from existing wells; altering existing on-site sewers; on-site demolition, removal, decontamination and recycling of former mercury cell processing buildings and building materials; cleaning storm drainage systems; investigation of berms surrounding the Semet Tar Ponds; design and construction of a lakeshore barrier wall and groundwater collection/treatment system; and removal of some contaminated sediments and floodplain soils from Geddes Brook and the East Flume. Investigations and long-term remedial actions at the various subsites are being performed by PRPs, pursuant to enforcement agreements between the PRPs and the State. EPA has contributed over $16.5 million to the state for various activities at the site including investigations; coordination and management at subsites; implementation of a citizen involvement plan; creation of a site-wide database; and establishment of a comprehensive enforcement program. Between 1998 and March 2010, eight Records of Decision (RODs) have been signed for cleanup plans at the various subsites. Selected remedies for contamination at the subsites include: dredging of sediments; excavation of soils; on and offsite treatment of contaminated materials; collection and treatment of contaminated groundwater; and capping of excavated soils and sediments.

Dredging and capping of contaminated lake sediments began in summer 2012. Approximately two million cubic yards of contaminated sediment will be removed during dredging. The dredging work is being performed by Honeywell International with oversight by the New York State Department of Environmental Conservation, the EPA, and the New York State Department of Health. Dredged lake sediment is transported four miles by a double-walled pipeline to a lined consolidation area located on the former Allied Chemical waste bed located off Airport Road in the Town of Camillus. Once there, the sediment is dried and permanently stored in heavy-duty plastic tubes. The water that drains from the tubes is treated onsite at the Camillus facility and pumped to Onondaga County's Metropolitan Syracuse Wastewater Treatment Facility for further treatment before being pumped back to the lake. Once the dredging has been completed, the tubes will be capped in a manner protective of human health and the environment.

Dredging and capping operations in Onondaga Lake are anticipated to be completed in 2015 and 2016 respectively. Honeywell estimates that more than 500 Central New York scientists, engineers, and skilled craft laborers are working on the project, and Honeywell plans to hire more local workers as the project continues.

More information about the status of the cleanup of the subsites and the lake bottom can be found on the New York State Department of Environmental Conservation’s Region 7 Project Information Web page.


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