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Onondaga Lake Superfund Site

Onondaga Lake Cleanup


Aerial View of Onondaga Lake

Onondaga Lake is located in central New York adjacent to the city of Syracuse. The lake covers an area of 4.6 square miles, has an average depth of 35 feet and a maximum depth of 63 feet. Its volume is about 35 billion gallons. The lake is approximately one mile wide and 4.6 miles long, and receives water from a land area, or drainage basin, of approximately 285 square miles in area, almost entirely within Onondaga County, New York.

Brief History

Before the American Revolution, the area surrounding Onondaga Lake was the center of the Iroquois Confederacy. European immigrants settled the area throughout the 17th and 18th centuries due in part to the presence of salty springs around Onondaga Lake. After the Erie Canal was built in the early 1800s, the booming salt industry in and around the city of Syracuse attracted many people. In the 19th century, Onondaga Lake served as a popular tourist attraction. The lake was populated with beaches, resorts and amusement parks.

Resort Area around Onondga Lake 1800s

Use of the lake changed dramatically when the water and lake bottom sediments became polluted with municipal sewage waste and industrial pollution which resulted in low oxygen levels and elevated levels of nutrients, harmful microorganisms such as disease causing bacteria, and toxic contaminants. For over 125 years industrial and chemical operations disposed a variety of pollutants to the lake. At one time industry discharged approximately 20 pounds of mercury to the lake each day. As a result of this, surface water was contaminated with mercury, and sediments were contaminated with PCBs, pesticides, creosotes, heavy metals (including lead, cobalt and mercury), PHAs and volatile organic compounds such as chlorobenzene. Groundwater at many upland sites around the lake was also contaminated.

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By the early 20th century, the lake's western shore was industrialized and polluted and the fishing and resort industry began to decline. By 1940 swimming in the lake was banned, and in 1972 fishing was banned. Onondaga Lake and related upland sites were added to the Federal Superfund National Priorities List (NPL) in 1994. The lake and related upland sites were also added to the New York State Registry of Inactive Hazardous Waste Disposal Sites (State Superfund Program).

In 1988 Atlantic States Legal Foundation (ASLF), a Syracuse-based organization providing legal and technical assistance to citizens and organizations dealing with environmental problems, filed a lawsuit against Onondaga County. ASLF alleged that Onondaga County's sewage treatment plant, Metro, and combined sewer overflow discharges were violating federal water pollution standards established under the Clean Water Act of 1972. The State of New York joined as a plaintiff, alleging that Onondaga County also violated the New York State Environmental Conservation Law. The parties settled the litigation in 1989 through a consent judgment, requiring the County to complete planning, design and construction of facilities to bring wastewater discharges from Metro into compliance with regulatory requirements.

In 1989 the State of New York filed a lawsuit against Allied-Signal, Inc.(Honeywell International, Inc. is the corporate successor of Allied-Signal) seeking to compel the company to clean up the hazardous substances that it and its predecessor companies had discharged into and around Onondaga Lake, and to pay damages for the destruction of natural resources. In 1992, the federal court approved a consent order requiring the company to conduct, subject to state supervision and approval, a comprehensive environmental study of the area and to evaluate the feasibility of various remedial alternatives.

Clean Up Achievements 1970s-1990s

Clean up actions for the lake began in the 1970s.

Recent Improvements

Onondaga County Wastewater Upgrades

Onondgaga County's Metro Wastewater Treatment Plant

Since 1990 Onondaga County has improved Metro's capacity to treat wastewater through projects such as advanced nutrient removal, odor control upgrades, an aeration system upgrade, digital system improvements, increased capacity for chemical storage and feed facilities, and digester modifications. As a result ammonia and phosphorus concentrations in the lake have declined significantly. Since 2007, the lake has been in full compliance with ambient water quality standards for ammonia and was officially de-listed for that parameter in the State's 2008 list of impaired water bodies. The lower concentrations have improved conditions for young fish and other sensitive forms of aquatic life and have enhanced fish spawning and migration patterns.

Between 1993 and 2009 phosphorus discharges from Metro were decreased by approximately 86 percent. The concentrations of phosphorus dropped to the lowest level ever recorded in the lake's upper waters and reached an impressive average of 15 micrograms per liter (parts per billion) in 2008. This can be attributed to upgrades at Metro. In addition, dissolved oxygen in the lake's upper waters has increased and the frequency of algal blooms is diminishing.

In addition to Metro upgrades, Onondaga County is implementing projects to control stormwater runoff and reduce the number of combined sewer overflows (CSOs). The amended consent judgment (ACJ) requires that by 2018 the County eliminate or capture for treatment 95% of the CSO volume generated during precipitation. Of the 70 total CSO discharges, 35 have been addressed as of 2010, resulting in an estimated 85% reduction in the volume of CSO discharges from rain and snowmelt on an annual basis.

Green Infrastructure Enhancements

Green Roof in Vancouver, Canada

Onondaga County officials, in cooperation with many community stakeholder groups, have taken a proactive approach to developing green infrastructure alternatives designed to reduce the amount of stormwater entering storm sewers and contributing to CSO discharges. Green infrastructure such as rain gardens, green roofs, porous pavement, vegetated infiltration basins, and tree plantings help reduce runoff by facilitating soil infiltration and the capture and reuse of stormwater before it enters the sewer system. More information about Onondaga County's "Save the Rain" program is available; view their website on the right column.

Cleanup of Industrial Pollution to Onondaga Lake

As a result of the industrial pollution, Onondaga Lake was designated a Superfund site in December 1994. The Onondaga Lake Superfund site includes the lake bottom, and subsites around the lake and along the tributaries that are sources of contamination. Currently 12 subsites have been determined part of the Superfund site. They are:

  • Onondaga Lake Bottom
  • Geddes Brook/Ninemile Creek
  • Willis Avenue
  • LCP Bridge Street - Operable Unit 1
  • Wastebed B/Harbor Brook
  • Semet Tar Beds
  • Town of Salina Landfill
  • Lower Ley Creek
  • Ley Creek PCB Dredging
  • General Motors - Inland Fisher Guide
  • National Grid - Hiawatha Boulevard
  • Wastebeds 1-8

The cleanup of each of these sites is being addressed through separate remediation plans. Investigations and long-term remedial actions at the various subsites are being performed by potentially responsible parties pursuant to enforcement agreements between these parties and the State. In addition, 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.

Besides the 12 subsites included in the Onondaga Lake Superfund Site, there are additional polluted sites around the lake that are being remediated by the State. They are:

  • Wastebeds 9-15
  • LCP Bridge Street - Operable Unit 2

Both Federal Superfund subsites and state sites are shown on this map.

Honeywell is remediating polluted upland sites that impact the lake for which they are the responsible party. For example, the former Linden Chemical and Plastics (LCP) site was a major source of mercury contamination in Geddes Brook, Nine Mile Creek and Onondaga Lake. As part of the site remediation, more than eight tons of mercury were removed from the plant property. Additional upland sites for which there are other responsible parties are also in various stages of remediation. As of 2010, Records of Decision (legal agreements) have been signed for cleanup plans at eight Superfund subsites.

Onondaga Lake Bottom

In 2007 the Federal Court approved an agreement requiring Honeywell International Inc. (the successor to Allied-Signal Inc.) to remediate the contaminated sediments in the bottom of the lake. The plan involves dredging contaminated sediments, capping approximately 580 acres of lake bottom sediments, and restoring habitat. Under the direction of NYSDEC, Honeywell is currently working in cooperation with a team of scientists, engineers and federal, state and municipal leaders on designs for the restoration of the lake, including a dredging strategy, a sediment containment area and wastewater treatment. The plan calls for sediments to be hydraulically dredged from the bottom of the lake and piped to a sediment consolidation area in Camillus, NY. Dredging is expected to begin in 2012.

Community Participation Working Groups (CPWGs) provide a forum for enhancing public dialogue, fostering public understanding, and encouraging input and discussion about the Onondaga Lake bottom cleanup. Information on the CPWGs is available via the links at right.

Mudboils - Their Effect on Onondaga Lake

Mud Boils in Tully Valley south of Syracuse

Located approximately 18 miles south of Syracuse, the Tully Valley has unique hydrogeologic features called mudboils. Mudboils have contributed significant amounts of sediment to Onondaga Creek and Onondaga Lake. Mudboils are volcano-like cones of fine sand and silt found along the floor of the Tully Valley. They range in size from several inches to several feet high and from several inches to more than 30 feet in diameter. Sediment from the mudboils enters Onondaga Creek which flows north into Onondaga Lake. Mudboils can erupt and form a large cone in several days. The flow might then continue for several years or stop as abruptly as it started.

Sediment loading from the mudboils is a concern because it degrades water quality, decreases water clarity, and reduces habitat for aquatic insects, fish spawning, and plant growth along Onondaga Creek, the Inner Harbor and Onondaga Lake. Onondaga Creek has contributed more than 50 percent of the annual tributary sediment load to the lake.

Dramatic reductions in sediment loading from the mudboils to Onondaga Creek occurred from the 1990s through 2009. An average of 30 tons per day of sediment from the Tully Valley mudboils to the lake was reduced to 1 ton per day. One of the main ways this was achieved was through the installation of two settling basins and several depressurization wells. The development of a new mudboil area downgradient of the 'main mudboil area' beginning in about 2010 has increased sediment loading to Onondaga Creek. While the remedial activities implemented in the past have been successful in reducing sediment discharge to Onondaga Creek, controlling mudboil discharges will require continuous, long-term attention. Fortunately, through a signed 2010 Consent Order that requires local environmental benefit projects, Honeywell will provide funding for five years to help address the mudboil problem on Onondaga Creek.

Non-Point Source Pollution

Non-point source pollution (NPS) comes from diffuse sources and is transported by stormwater runoff and wind. Common non-point sources are associated with land use activities such as agriculture, forestry, urbanization and construction. Typical agricultural sources of NPS pollution existing in the Onondaga lake watershed include soil erosion and over-grazed pastures, unstabilized barnyards and manure runoff. Sediment from eroded stream banks and road banks, nutrients and chemicals from man-made fertilizers and pesticides contaminate waterways when they are washed into creeks and streams. Urban forms of NPS pollution include litter and debris from streets that are carried by stormwater, fertilizer and pesticides, construction site runoff and petroleum products.

Means to address this problem are many. Onondaga County has a litter vacuum truck which is now used to remove floating trash from stormwater catch basins and skimmer vessels are used to remove floating waste from the Inner Harbor. Trash removal helps to improve the aesthetics of the lake and reduces ingestion or entanglement hazards to wildlife. Agricultural Environmental Management is a voluntary program where farmers work with a team of local resource professionals to develop comprehensive farm plans using a tiered process. The Onondaga County Soil and Water Conservation District oversees this grant-funded program which is active in the Onondaga Creek and Ninemile Creek watersheds. As of 2009, 57 of 67 farms in the Onondaga Lake watershed had participated in the program.

Other projects which have been implemented to reduce non-point source pollution include road bank/stream bank stabilization, increased use of phosphorus-free fertilizers, and measures to control road and stream bank soil erosion and stormwater runoff.

More Information

More information on the current status of the clean up of the subsites around the lake and on the clean up of the lake bottom can be found on the main Region 7 clean up page.

Summary of Lake Improvements

  • Onondaga Lake is exhibiting a remarkable recovery and significant water quality improvements have been documented. Phosphorus, ammonia, and other major pollutants in the lake have decreased substantially.
  • Phosphorus discharges to Onondaga Lake from the sewage treatment plant were reduced by approximately 86% between 1993 and 2009. Phosphorus levels in the upper waters are in the best condition in over 100 years.
  • Chloride concentrations have decreased from 1800 milligrams per liter in 1985 to 450 milligrams per liter in 2009. Lower levels benefit the lake by improving plant and animal diversity and habitat.
  • Successful remediation projects have reduced Tully Valley mudboil sediment loading to Onondaga Creek from an average of 30 tons (about three large dump trucks) per day to less than one ton (about a pick-up truck load) per day on average over the past 15 years.
  • Onondaga Lake fisheries are improving more quickly than anticipated and over 56 species have been documented in the lake. This is an impressive increase from the 9 to 12 species that were recorded in the lake during the 1970s.
  • National sporting competitions and professional fishing events are scheduled each year, and local anglers use the lake on a regular basis during the summer months. In 2008, the North American Fishing Club named Onondaga Lake one of the top ten bass fishing destinations in the United States.
  • Plant and animal diversity in and around the lake is exhibiting remarkable improvement. With the recent improvements in Onondaga Lake water quality, a nearly four-fold increase in aquatic plant cover was documented from 2000 to 2009. Plants provide valuable spawning and nursery habitat for the fish community.
  • An underground barrier wall located on the western shoreline of Onondaga Lake diverts polluted groundwater to a state-of-the-art treatment plant instead of flowing directly into the lake.
  • Bird diversity in and around the lake is exhibiting impressive changes, highlighted by sightings of bald eagles, great egrets, osprey, kingfishers, and numerous species of waterfowl.

Subscribe to DEC's Onondaga Lake News email list to receive occasional project information, updates and public meeting announcements about the remediation of Onondaga Lake and associated upland sites.

This information was adapted from the State of Onondaga Lake Report 2010 by the Onondaga Lake Partnership and the Onondaga Lake Watershed Progress Assessment and Actions Strategies by the Central New York Regional Planning and Development Board and the Onondaga Lake Partnership. The DEC is a member of the Onondaga Lake Partnership and works cooperatively with federal, state and local governments on the cleanup of Onondaga Lake.