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Back to homeOnondaga Lake News: Honeywell Cleanup Status, Water Quality, and Recreation Updates
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Onondaga Lake News: Honeywell Cleanup Status, Water Quality, and Recreation Updates
Onondaga Lake, the 4.6 square mile lake immediately northwest of downtown Syracuse, is one of the most studied and most polluted lakes in the United States. The lake has been the subject of a $451 million Honeywell-funded EPA Superfund remediation since 2005, with the sediment cap completion in 2017 and ongoing monitoring through 2030. Recent water quality improvements have made portions of the lake swimmable for the first time since 1940, with designated swim areas opening at Onondaga Lake Park starting summer 2024. The lake is owned by the State of New York and managed jointly by NYSDEC and Onondaga County Parks.
Onondaga Lake water quality: NYSDEC Onondaga Lake. CNY Signal Onondaga Lake coverage: cnysignal.com.
The Solvay Process and a Century of Pollution
Onondaga Lake’s pollution legacy began in 1884 when the Solvay Process Company began
producing soda ash on the southwest shore. The Solvay Process discharged calcium carbonate
sludge, mercury, naphthalene, BTEX hydrocarbons, and PCBs into the lake for nearly 100 years
before closing in 1986. At peak production in the 1950s and 1960s, Solvay was discharging up
to 7 metric tons of mercury per day directly into Onondaga Lake. Per the EPA Superfund
record, total mercury contamination in the lake sediments reached 165,000 pounds. The Solvay
Process Company was acquired by Allied Chemical, then Allied Signal, then Honeywell, which
inherited the cleanup liability.
The $451 Million Honeywell Remediation
The EPA Onondaga Lake Superfund site was added to the National Priorities List in 1994.
Per the EPA Record of Decision (ROD), the remediation includes: (1) sediment dredging of
2.65 million cubic yards from the most contaminated bays (completed 2017), (2) sediment
isolation cap covering 425 acres of lake bottom (completed 2017), (3) wastewater treatment
plant upgrade for the Onondaga County Metro plant (completed 2010), (4) tributary controls
on the Ninemile Creek and Geddes Brook tributaries (completed 2017), and (5) ongoing
monitoring through at least 2030. Total cost as of 2024: $451 million, paid by Honeywell.
2024 Water Quality Improvements
Per the NYSDEC 2024 Onondaga Lake Annual Report, the lake water quality has improved
significantly: total phosphorus dropped from 100 micrograms per liter in 1990 to 14 in
2024 (within the federal water quality standard). Total mercury in fish tissue dropped 83
percent from 1989 baseline. Lake clarity (Secchi disk depth) increased from 1.2 meters in
1990 to 4.1 meters in 2024. The lake meets EPA recreational water quality standards in the
designated swim areas, and the NYSDEC fish consumption advisory has been relaxed for several
species (walleye, perch, bass) although mercury bioaccumulation in older predator fish
remains a concern.
Beach Reopening and Recreation
Onondaga Lake Park, operated by Onondaga County Parks, is a 7.5 mile lakeside park along
the western shore. The park reopened a designated swim area at the West Shore Beach in
summer 2024 for the first time since 1940. The swim area is monitored daily during the
summer season for E. coli and harmful algal blooms (HABs). The Onondaga Lake Park Marina
hosts canoe and kayak rentals, and a 5-mile paved bike path runs the length of the western
shore. The Salt Museum, the Skiddy Park amphitheater, and the Liverpool village boardwalk
are all directly connected to the park.
Harmful Algal Blooms (HABs)
Per NYSDEC HABs reports, Onondaga Lake has experienced 12 to 18 HAB notifications per year
in 2020 to 2024, primarily blue-green algae (cyanobacteria) blooms in late summer. The blooms
are driven by nutrient loading from the Onondaga Creek watershed (largely agricultural runoff
from the upper watershed in Otisco, LaFayette, and Pompey towns). HAB events trigger swim
advisories at the West Shore Beach. NYSDEC’s HABs notification system at
dec.ny.gov/chemical/77118.html
publishes real-time bloom alerts.
Onondaga Lake Park Visitor Statistics
Per the Onondaga County Parks 2024 visitor count, Onondaga Lake Park hosted approximately
1.4 million visits in 2024, up from 980,000 in 2019. The park is the second-most visited
county park in New York State after Niagara Falls State Park. Peak visitation is summer
weekends and the May-June Liverpool Smokin’ BBQ festival. The county is investing $32 million
in park improvements through 2028 including expanded parking, a new amphitheater, and a
boathouse renovation.
The Onondaga Nation Sacred Site Designation
Onondaga Lake holds deep cultural and religious significance for the Onondaga Nation,
which considers the lake the birthplace of the Iroquois Confederacy (Haudenosaunee) circa
1142. The Hiawatha Belt, the Great Law of Peace, and the founding of the Five Nations
(later Six Nations) confederacy is recorded in oral tradition as having occurred on the
shores of Onondaga Lake. The Onondaga Nation maintains an active land claim covering 4,000
square miles of central New York including the lake. The 2010 Onondaga Lake Vision document,
published jointly by the Nation and the local communities, sets shared cleanup and stewardship
priorities.
Ongoing Monitoring and Issues
Per NYSDEC’s 2024 monitoring report, the lake’s persistent issues include: residual
mercury bioaccumulation in older fish species, occasional sediment cap erosion at the
Geddes Brook outlet (under repair), nuisance Cladophora algae blooms in shallow areas,
and chloride levels elevated above natural baseline due to legacy salt contamination from
the upper watershed. The cleanup is considered substantially complete; ongoing work focuses
on monitoring, maintenance, and adaptive management. Honeywell remains liable for cleanup
costs through at least 2030 and possibly longer if monitoring detects new contaminant
mobilization.
Frequently Asked Questions
Is Onondaga Lake safe to swim in?
The designated swim area at Onondaga Lake Park West Shore Beach reopened in summer 2024 for the first time since 1940 and meets EPA recreational water quality standards. The swim area is monitored daily for E. coli and harmful algal blooms. Other parts of the lake are not designated swim areas and may not meet swim standards.
What was the Solvay Process?
The Solvay Process Company manufactured soda ash on the southwest shore of Onondaga Lake from 1884 to 1986. The process discharged mercury, calcium carbonate sludge, naphthalene, BTEX hydrocarbons, and PCBs into the lake. At peak in the 1950s-1960s, Solvay discharged up to 7 metric tons of mercury per day. Total mercury contamination reached 165,000 pounds in lake sediments.
Why is Onondaga Lake polluted?
Two centuries of industrial discharge: the Solvay Process Company (1884-1986) was the primary polluter, contributing 165,000 pounds of mercury plus chemical sludge. Additional pollution came from municipal sewage discharge until the 1970s and from agricultural runoff in the upper watershed. The current $451 million EPA Superfund cleanup, paid by Honeywell (Solvay’s corporate descendant), began in 2005.
How much did the Onondaga Lake cleanup cost?
$451 million as of 2024, paid entirely by Honeywell as the corporate successor to the Solvay Process Company. The cleanup includes 2.65 million cubic yards of sediment dredging, a 425 acre sediment isolation cap, wastewater treatment upgrades, tributary controls, and ongoing monitoring through at least 2030.
Who owns Onondaga Lake?
Onondaga Lake is owned by the State of New York and managed jointly by NYSDEC and Onondaga County Parks. The lake also holds deep cultural and religious significance for the Onondaga Nation, which considers it the birthplace of the Iroquois Confederacy circa 1142 and maintains an active land claim covering parts of the watershed.