Onondaga Lake NPL Site

State TrusteeAO Bureau

Also Known As


Incident Type



New York

Case Status



Onandaga Lake


Contaminants of Concern Include

Affected DOI Resources Include

Migratory Birds

Financial Summary

Restoration Funds Collected:


*Restoration Funds Allocated:


*Restoration Funds Remaining:


* Restoration Funds can contain multiple settlements/projects. All collections are placed in interest bearing accounts. For detailed information on individual settlements/ projects please visit: NRDAR Status Report

Case Description

Onondaga Lake is located in Onondaga County, New York, and lies to the northwest of the city of Syracuse. The Lake itself covers 11.9 square km and has a shoreline that includes a shallow near-shore shelf bordered by terrestrial areas of wetlands, wooded areas, and urban and industrial development. The northern shore of the lake includes parkland; the southern and western shorelines, however, are dominated by industrial waste beds, consisting mainly of ionic wastes, many of which have been revegetated. Current land use has been the result of historic land management practices; future land use may change as a result of remedial efforts and/or changes in land use planning.

Over the past century and a half, Onondaga Lake (Lake) and its surroundings have been adversely affected by a range of anthropogenic activities. The lake has been the recipient of over 100 years of Honeywell- (formerly Allied Signal) related wastes, as well as industrial and municipal sewage discharges from the municipal sewer system and by combined sewer overflows (Metro facility). Other industries in the area have contributed contamination as well. The various sites and areas of concern consist of Honeywell and non-Honeywell sources and potential sources. The lake is heavily contaminated with mercury (estimated release of 165,346 lbs between the years 1946-70) and other compounds from industrial activities. The deposition of calcium carbonate on the lake bottom has severely impacted its habitat value, and the lake is nutrient enriched, resulting in oxygen only in the upper levels of the lake.

Onondaga Lake was placed on the National Priorities List (NPL) on December 16, 1994. Several sites have been listed as "sub-sites" of the Onondaga Lake NPL site. Current contaminant loads to the lake are primarily derived from Honeywell sites on the lake perimeter as well as in its vicinity, with surface water and groundwater pathways delivering much of the associated contamination to the lake. Dense non-aqueous phase liquid plumes at the Willis Avenue and Wastebed B/Harbor Brook sub-sites also convey chemicals of concern (COC) to the lake.

Contaminants of concern being transported to the lake from the Honeywell facilities include, among others, mercury, BTEX (benzene, toluene, ethylbenzene, and xylenes) compounds, chlorinated benzenes, naphthalene and other polycyclic aromatic hydrocarbons (PAHs), and ionic wastes. Historically, the contaminants included a greater assortment at generally higher concentrations. Besides the Honeywell upland facilities on the lake perimeter and in the Ninemile Creek basin, recent and historical evidence documents the presence of Honeywell wastes within the lake itself which resulted from historical waste discharges to the lake (e.g., via the East Flume). This in-lake waste deposit is estimated to be over 10.9 yd thick, with a maximum reported thickness of 15.0 yd, representing over 3 million cubic yards of material. This material represents some of the most contaminated sediment contained within the lake. Evidence indicates ongoing re-release of contamination from the area suggesting that contaminants contained in the deposit are not sequestered from the lake. Its location in the littoral zone is considered to be relatively unstable, with the material subject to wind-driven re-suspension and bioturbation, among other re-release processes.

The lake was closed to fishing from 1970 until 1986 due to mercury contamination. In 1986 the lake was opened to catch and release fishing, however, NYS Department of Health (NYSDOH) issued health advisories for the lake; consumption advisories remain in effect. NYS has initiated an NRDA for the Onondaga Lake system, the DOI intends to coordinate its damage assessment activities with those of NYS. In addition, extensive efforts are underway by NYS, the United States Environmental Protection Agency (EPA), the U.S. Army Corps of Engineers, local governments, and non-governmental organizations to restore Onondaga Lake. The DOI further intends to coordinate its restoration planning with these ongoing activities.

Hazardous substances released to Onondaga Lake include, but are not limited to the following: mercury, PCBs, lead, cadmium, chromium, nickel, benzene, chlorinated benzenes, toluene, xylene, PAHs, and pesticides, including aldrin and dichloro-diphenyl-trichloroethane (DDT).

Mercury is the primary contaminant of concern regarding trust resources. It is found in sediments throughout the lake, generally in excess of 1 ppm in surface sediment, with higher concentrations found in the Ninemile Creek delta and in sediments in the southwestern portion of the lake in an area known as “in-lake waste deposit” (ILWD). The southwestern portion of the lake also contains some of the highest concentrations of other chemicals such as BTEX, PCBs, PAHs, dioxins, and furans.

Unlike most waterbodies in urban areas, the lake does not have residences located on its shoreline, enhancing its value to fish and wildlife resources. Onondaga Lake is within the Atlantic flyway and provides habitat for a number of DOI trust species, including 112 species of birds during the breeding season, 70 over-wintering species, including bald eagle (Haliaeetus leucocephalus), and 15 waterfowl and 6 waterbird species. Migratory shorebirds forage in the shallow water and mud flats along the lakeshore. Waterfowl use the lake for nesting during the breeding season, and for feeding and resting during migration they also nest along the northwest shoreline of the lake and in marshes near the Ninemile Creek waste beds.

Prior to the onset of industrial discharges, the lake supported a coldwater fishery with species such as Atlantic salmon, cisco, American eel, and burbot. By 1927, a fishery survey reported that the coldwater fishery had been disturbed due to the impacts of soda ash production. The Onondaga Lake fishery is now characterized as a warmwater fish community dominated by the pollution-tolerant gizzard shad, freshwater drum, carp, and white perch. Sunfish are abundant in the littoral zone. The lake supports several important sportfish, including channel catfish, largemouth bass, smallmouth bass, and walleye. A total of 57 species have been recorded between 1927 and 1994.

Credit: New York State Dept of Environmental Conservation

Case Documents

 Document TypeDocument NameDocument Date
Data pager
Data pager
Page size:
 22 items in 2 pages


 Factsheet Fact Sheet 2009  
 Factsheet Fact Sheet 2011 11/01/2011
 Factsheet Fact Sheet Dec 2012 12/01/2012
 Factsheet FWS Restoration Projects 2018 12/03/2018
 Factsheet Restoration Fact Sheet 07/17/2014


 Assessment Plan Assessment Plan Addendum 10/01/2012


 Consent Decree Lake Onondaga - Honeywell consent decree 03/14/2018
 Bankruptcy Proof of Claim 04/08/2011


 Restoration Implementation Report Final Restoration Workplan 06/19/2018
 Restoration Plan Onondaga Draft Restoration Plan 04/23/2017
 Restoration Plan Potential Restoration Redevelopment Projects Database 10/30/2013

Assessment;Case Funding (Showing 9 of 11 items. Group continues on the next page.)

 Study Report Assessment of Mercury Exposure to Bats 09/01/2012
 Study Report Assessment of Mercury in Birds 2008-2009 11/05/2012
 Study Report Bird Report Appx III 01/14/2011
 Study Report Bird Report Appx IV 09/16/2011
 Study Report Eagle Risk Assessment Mercury 03/24/2015
 Study Report Eagle Risk Assessment PCBs 03/24/2015
 Study Report Final Bat Report 10/13/2009
 Study Report Final Bird Report 09/16/2011
 Study Report Mercury in the Invertivore Food Web 03/01/2013

Map View

Case Contact

New York Ecological Services Field Office

Cortland, NY | (607) 753-9334 | http://www.fws.gov/northeast/nyfo/

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