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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) 407-0400

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Public Notice: Five-Year Review, Semet Residue Ponds Subsite [24 KB, 1 pp]

Public Notice – First Five-Year Review, Lake Bottom Subsite [20 KB, 1 pp]

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

Supplemental Human Health Risk Evaluation, Lakeview Amphitheater Facility

Onondaga Lake is located along the northern side of the City of Syracuse in Onondaga County, New York. The lake itself covers an area of 4.6 square miles. Its shoreline borders the city of Syracuse, as well as the towns of Geddes and Salina and villages of Solvay and Liverpool. The lake receives water from a drainage basin of approximately 285 square miles, located almost entirely within Onondaga County. The lake flows into the Seneca River, then into the Oswego River and, ultimately, Lake Ontario.

Because of extensive contamination of the lake, adjoining tributaries and several upland sites, the Onondaga Lake Superfund site was added to the EPA’s National Priorities List 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 site is being addressed through federal, state, and potentially responsible party actions. New York State is the lead agency for the lake bottom cleanup and all but one of the subsites.

Historically, industrial pollutants and municipal sewage waste were routinely discharged into the lake. As a result, the surface water is contaminated with mercury and the 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. Groundwater 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 the EPA and New York State have determined that the site poses no immediate threat to human health or the environment while studies and remedial work 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 the potentially responsible parties pursuant to enforcement agreements between these parties and the state of New York. The EPA contributed more than $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 November 2014, 10 Records of Decision (RODs) were signed for cleanup plans at the various subsites. Selected cleanup 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 of contaminated lake sediments (Lake Bottom subsite) began in summer 2012 and was completed in November 2014. Approximately 2.2 million cubic yards of contaminated sediment was removed from the lake bottom and three shoreline areas. The dredging and related capping and habitat restoration 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. Capping and habitat restoration activities will continue through 2016.

During dredging, the dredged lake sediment was 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 was dried and permanently stored in heavy-duty plastic tubes. The water that drained from the tubes was pre-treated on-site at a wastewater treatment plant constructed adjacent to the consolidation area and then was pumped to Onondaga County's Metropolitan Syracuse Wastewater Treatment Facility for further treatment before the treated water was pumped back to the lake. Now that the dredging has been completed, the tubes will be covered with an engineered cap and properly closed to prevent possible exposures to people or wildlife.

Under Superfund, five-year reviews are conducted to ensure that the cleanups continue to be protective of human health and the environment. The first five-year review for the Lake Bottom subsite is underway and is expected to be completed by August 2015.
In 2014, the EPA finalized its plan to clean up contaminated soil and sediment at the Lower Ley Creek subsite, located in the city of Syracuse and town of Salina. The cleanup will include excavation and capping of contaminated soil and sediment in Lower Ley Creek and disposal of the excavated soil and sediment. Negotiations are underway with the parties responsible for contamination at the site to get them to perform the engineering and cleanup work.

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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