Onondaga Lake, NY has been described as the most polluted lake in the United States.

The Upstate Freshwater Institute and its staff have been conducting research on Onondaga Lake for more than twenty-five years. This work has resulted in the publication of a book summarizing studies conducted on Onondaga Lake. Additionally, UFI has prepared over 61 manuscripts on a wide range of topics concerning Onondaga Lake's ecology and water quality for publication in peer-reviewed science and engineering journals (including a journal issue devoted entirely to Onondaga Lake). UFI has an on-going comprehensivemonitoring program for the lake, its tributaries and adjoining portions of the Seneca River. In 1999, UFI developed and sponsored the Annual Onondaga Lake Scientific Forum along with co-sponsors: SUNY-College of Environmental Science and Forestry and Syracuse University, L.C. Smith College of Engineering and Computer Science.

UFI Research vessel on Onondaga Lake photo by Ron Trinca

What's New?

• Onondaga Lake/Seneca River EMPACT Project Web Site
• The Annual Onondaga Lake Scientific Forum
• Recommendation for NRC Review

UFI and Onondaga Lake

As data collection and analysis have increased, the lack of effective communication of this information to regulatory agencies and, more importantly, the Syracuse community, has stymied reclamation initiatives. Reliable polling results indicate that while an overwhelming percentage (92%) of local residents know the lake is severely polluted and effectively "off limits" to them, they have little specific knowledge of why that is, or how to rectify the situation.

UFI is concerned with the health of Onondaga Lake, not only from a research perspective, but as a member of the community. We have designed this section of our web site as a community resource to educate the community about the water quality issues facing Onondaga Lake. UFI will expand this area in the future, with the community's help. Please email ( )  your ideas and suggestions on topics, issues, and concerns regarding Onondaga Lake.

A Brief History

The Syracuse area was settled (late 1700s), in large part, because of Onondaga Lake and the unusual hydrogeology of the region. The region's expansion in the 1800s was coupled to the growth of commercial salt (NaCl) production from brine wells that adjoined the lake and construction of the Erie Canal.

Before European settlement, Onondaga Lake was oligo-mesotrophic (low levels of aquatic plant growth). The lake initially supported a commercially viable cold-water fishery which was sustained by the harvesting of Onondaga Lake Whitefish and Atlantic Salmon. A number of resorts were built along its shoreline in the late 1800s. As the industrial revolution took hold, and the city's population expanded, the lake was used increasingly for the disposal of domestic and industrial waste. Conspicuous signs of deterioration of the lake ecosystem began to emerge by the end of the 19th century. The cold-water fishery was lost by 1890. Ice-harvesting was banned in 1901, swimming in 1940, and fishing (due to mercury contamination) in 1970.

Since passage of the Clean Water Act in 1973, several actions have been taken to abate domestic waste inputs to the lake, and in 1986 the major industrial polluter closed its operations. In 1994, a number of sites proximate to the lake were added to the federal "superfund" National Priority List.

Several initiatives have been undertaken to clean up Onondaga Lake. A 15 year multi-stage program is underway to improve sewage treatment and eliminate related violations of water quality standards in the lake. The initial stage of the program is estimated to cost $380 million dollars, which is equivalent to an expenditure of almost $1,000 per capita within the watershed. At the conclusion of the initial stages, the program will be evaluated as to its success or failure. If further remediation is deemed necessary, a third stage (and additional dollars) will be added to the program in an attempt to meet water quality standards.

Description of Onondaga Lake

Onondaga Lake has a surface area of 12 km² (4.5 square miles), a volume of 131 x 10⁶ m³ (35 billion gallons), and a maximum depth of 19.5 m (64 feet). The watershed (642 km2, 244 square miles) supports a population of approximately 450,000, that resides mostly in Syracuse and adjoining suburbs. The lower reaches of Onondaga Creek drain a significant portion of the City of Syracuse, and receive inputs of dilute untreated domestic waste during runoff events (storms and snow melts) via approximately 40 combined sewer overflow structures (CSOs) within the City. Effluent discharged to the southern end of the lake from the Metropolitan Syracuse Wastewater Treatment Plant (METRO) contributes almost 20% of the annual inflow, and often is the single largest input in late summer. No other lake in the United States

Combined Sewer Overflows releasing into Onondaga Creek

receives as much of its inflow as treated wastewater. The lake flushes approximately 4 times a year, that is its water volume is replace four time each year. This is much more rapid than Skaneateles Lake which flush once every 12 years or Lake Superior flushes only once every 191 years! With its rapid flushing rate, Onondaga Lake should respond quickly to changes in material loading.

Onondaga Lake and adjoining portions of the Seneca River are tightly linked with respect to water quality, ecological concerns and management issues. Fish populations actively migrate between these systems (i.e., fish that have been trapped and tagged in Onondaga Lake have been caught by fishermen in the Seneca Rivers and Oneida Lake).

Municipal Waste

Aquatic plants (i.e. algae) require phosphorus and nitrogen for growth. Excessive amounts of these nutrients can cause a lake to become overgrown with aquatic plants. High concentrations of nitrogen species (i.e., free ammonia) are harmful to other aquatic life (i.e., fish).

The Metropolitan Syracuse Wastewater Treatemnt Plant (METRO) has 

METRO effluent flowing into Onondaga Lake

discharged its effluent directly to the southern end of the lake since the 1920's. The input of domestic waste had profound negative impacts on the lake, particularly associated with the large loads of ammonia (nitrogen; UFI #268) and phosphorus (UFI # 277). These loads caused routine violations of toxicity standards for forms of nitrogen (UFI #268), and severe manifestaions of cultural eutropication, including algae blooms (UFI #262), poor clarity (UFI #262), and depleted oxygen (UFI #231). Dramatic reductions in loading of these constituents from METRO have been achieved through implementation of advanced treatement (UFI #285). These reductions have eliminated violations of toxicity standards for forms of nitrogen(UFI #258) and have transformed the lake from hypereutrophic to upper mesotrophy (UFI #277). However METRO remains (by 2012) the single largest source of bioavailable phosphorus (UFI #284) and nitrogen (in the form of nitrate, that is not toxic) to the lake.

Industrial Waste

The primary source of industrial waste to the lake has been a soda ash (Solvay

Waste beds on west shore of Onondaga Lake

Process)/chlor-alkali facility located on the lake's western shore. This facility discharged large quantities of ionic (mostly chloride, sodium,and calcium (UFI #65) waste to the lake, until its closure in 1986. It was the single largest source of chloride to Lake Ontario (UFI #65). The residual load of ionic waste from approximately 1,000 acres of "waste beds" adjoining the lake continues to be substantial (approximately 12% of pre-closure load; UFI #217). Large sediment loads (UFI #249) that enter the lake from Onondaga Creek have been attributed to solution mining activities by the manufacturer. This facility also discharged approximately 75,000 kg of mercury to the lake over the 1946-1970 interval.

Mechanistic Modeling

UFI has developed, tested, and applied a number of mechanistic models for Onondaga Lake to support management action and related research; these include hydrodynamic/transport, water quality, and optics models. Mass balance models for the lake simulate chloride, fecal coliform bacteria, total phosphorus, nitrogen species, and dissolved oxygen. Several of these models have been formally approved by the State of New York and used to evaluate management options. The modeling program for Onondaga Lake is ongoing; models continue to be tested and modified based on new monitoring data. The goals of the program are to improve the credibility and capability of these invaluable management tools. Further, these frameworks are valuable research tools, used in the synthesis of interdisciplinary data and testing of hypotheses.

Onondaga Lake as a Community Resource

Although Onondaga Lake is severely impacted by pollution, it remains a potentially valuable

Onondaga L. shoreline recreational trail

resource to the community. The lake's setting draws many visitors. More than one million people visit Onondaga Lake each year, making it one the most visited lakes in Central New York. However, the recreational activities are largely limited to the surrounding park land owned by Onondaga County. Imagine the potential of this resource if the waters of the lake could be fully utilized.