Some of New York’s largest flows of landfill wastewater originate in the Finger Lakes, where a new statewide analysis identifies Seneca Meadows, High Acres and the Ontario County landfill among the leading sources of leachate sent to municipal sewage treatment plants.
The Aug. 6 report from New York River Watch argues that New York has a systemic regulatory gap allowing landfill leachate — water that has passed through garbage and picked up contaminants along the way — to be routed through municipal treatment plants that were primarily designed to process sewage rather than the complex mixture of chemicals found in landfill waste.
The report estimates that New York municipal sewage treatment plants accepted about 532 million gallons of landfill leachate annually between 2019 and 2023. Roughly one-third eventually passed through treatment plants that discharged into waters officially designated as drinking water sources, according to the analysis.
For the Finger Lakes, the findings are particularly significant because the region contains several of the state’s highest-volume landfills, multiple sewage plants accepting leachate and waterways that eventually connect with major drinking water systems.
The authors describe the practice as the “Leachate Loophole,” but acknowledge important limitations in the underlying data. Their estimates are based largely on landfill compliance reports, municipal records and Freedom of Information Law responses, and the report says some records contained major discrepancies or gaps.
Seneca Meadows ranked No. 1 in New York
Seneca Meadows in Seneca County generated more leachate sent to municipal sewage treatment plants than any other landfill examined in the report.
The analysis estimates Seneca Meadows averaged 65.1 million gallons annually between 2019 and 2023.
High Acres landfill, located in Monroe and Wayne counties, ranked second statewide at approximately 42.5 million gallons per year.
The Ontario County landfill ranked eighth at approximately 22.8 million gallons annually.
Together, those three Finger Lakes-area facilities accounted for more than 130 million gallons of average annual leachate generation in the report’s dataset.
Seneca Meadows is privately owned and operated by Waste Connections. High Acres is operated by Waste Management, while the municipally owned Ontario County landfill is managed by Casella.
The report found that private companies manage about 56% of the leachate generated by active landfills statewide. Waste Connections, Waste Management and Casella collectively manage roughly half of New York’s active-landfill leachate volume included in the analysis.
Other regional sources identified in the report include the Chemung County landfill at about 9 million gallons annually and the Steuben County landfill in Bath at approximately 6.8 million.
The report also identified leachate from several closed sites, including an inactive Auburn landfill averaging an estimated 940,000 gallons annually, former Steuben County landfill sites and an inactive Yates County site averaging about 150,000 gallons per year.
Seneca Falls, Auburn and Canandaigua among plants accepting leachate
The Finger Lakes also contains several municipal wastewater plants that ranked prominently in the report.
The Seneca Falls sewage treatment plant accepted an estimated 13.9 million gallons annually during the study period and discharged treated effluent into the Seneca River.
Auburn’s plant accepted approximately 10.6 million gallons annually, with its discharge entering the Owasco Lake Outlet.
Canandaigua accepted approximately 7.2 million gallons annually, according to the report, with effluent discharged into the Canandaigua Feeder Outlet Canal.
Bath ranked among the 10 highest-volume leachate-accepting treatment plants statewide at approximately 15.7 million gallons per year, though the material reaches the village plant after first passing through Steuben County’s dedicated leachate pretreatment facility. Bath discharges into the Cohocton River.
The report estimates that the Seneca River received approximately 13.9 million gallons annually through this pathway, the Owasco Lake Outlet received about 10.6 million gallons, the Chemung River about 9 million and the Canandaigua Feeder Outlet Canal about 7.2 million.
Those figures do not mean that an equivalent volume of raw leachate was directly dumped into each waterway. Leachate is mixed with substantially larger volumes of municipal wastewater before treatment and discharge.
The central argument made by New York River Watch is that dilution does not necessarily remove the persistent chemicals contained in the original leachate.
Report questions what sewage plants can actually remove
Municipal sewage plants are primarily designed to remove conventional wastewater pollutants associated with human sewage, including biological oxygen demand, suspended solids and bacteria.
The report argues that their permits generally do not require comprehensive removal or monitoring of the wide range of synthetic chemicals potentially present in landfill leachate.
The authors say that means some contaminants may pass through with treated wastewater, while others can become concentrated in sewage sludge.
New York River Watch argues this creates a regulatory mismatch: contaminants regulated when found in finished drinking water may not necessarily be subject to equivalent limits when wastewater plants discharge upstream or into watersheds connected to drinking water sources.
The report does not conclude that drinking water supplied to residents is unsafe or that leachate disposal has caused specific illnesses.
It explicitly says considerably more information would be necessary to determine whether current disposal practices are producing specific health effects under real-world exposure conditions.
Instead, the report raises questions about whether existing treatment and permitting systems adequately prevent persistent chemicals from moving through the waste stream and back into the environment.
PFAS found in every landfill tested for it
Researchers compiled chemical monitoring information from 39 landfills and identified 187 different chemicals detected in at least one facility.
The findings included pesticides, toxic metals, petroleum-related compounds, plastic chemicals, polycyclic aromatic hydrocarbons and PFAS.
Testing was not uniform among facilities, so the authors caution that the results cannot be used to directly compare chemical concentrations or prevalence from one landfill to another.
Nine landfills in the dataset were tested for PFAS, and the chemicals were detected at all nine.
Researchers identified 29 different PFAS compounds. PFOA and PFOS were detected at least once at every landfill tested for them.
The report says those compounds were also detected in liquid that had already passed through reverse osmosis treatment at Seneca Meadows.
Twenty-seven metals were found across the landfill monitoring records, including arsenic, lead, mercury, cadmium and chromium.
Researchers also identified 50 pesticide chemicals and numerous compounds historically used in plastics and industrial products.
Some of the chemicals detected have been banned or phased out for decades but persist because older products remain buried in landfills and continue breaking down.
Seneca Meadows uses reverse osmosis, but waste remains
Seneca Meadows represents one of the report’s clearest examples of the challenges associated with treating leachate before it enters a municipal sewer.
The landfill uses reverse osmosis to filter a portion of its leachate.
The cleaner liquid produced by the process, known as permeate, can be sent by sewer to the Seneca Falls wastewater treatment plant.
But reverse osmosis does not make contaminants disappear. It separates them from the water, creating a concentrated residual waste stream that must still be handled.
The report says some Seneca Meadows concentrate was historically sent to other sewage treatment plants. Waste Connections reported sending concentrate to the Passaic Valley Sewerage Commission in New Jersey in 2021, although that facility has since stopped accepting it.
Since 2022, Seneca Meadows has also evaporated some concentrate onsite, according to the report.
New York River Watch argues that those disposal methods illustrate the difficulty of solving the leachate problem without simply transferring concentrated pollution from water to another location or environmental medium.
Seneca Falls briefly stopped taking landfill leachate
The report also traces changing municipal policies toward leachate.
In 2024, the Seneca Falls Town Board declined to renew its leachate treatment agreement with Seneca Meadows.
At the time, concerns included treatment fees, wastewater plant capacity, testing requirements, potential damage to the facility and whether additional upgrades could be needed.
The report says Seneca Falls was again accepting pretreated leachate as of 2026.
Elsewhere, the village of Chittenango stopped accepting Seneca Meadows leachate in 2023 after municipal employees received information about its PFAS content, according to the report.
Those local decisions illustrate how much authority individual municipalities can have over whether they accept landfill wastewater.
Steuben County proposes $25 million treatment upgrade
Steuben County operates what the report identifies as New York’s only dedicated landfill leachate pretreatment plant.
Ten landfills sent leachate through the facility during the period examined.
The plant targets conventional pollutants including biological oxygen demand, suspended solids, pH and metals before sending treated liquid to the Bath sewage treatment plant.
The remaining sludge is returned to the neighboring Bath landfill.
Once the liquid passes through the village treatment plant, effluent is discharged into the Cohocton River, which eventually feeds the Susquehanna River system.
Steuben County has developed a $25 million plan to modernize the pretreatment facility and has sought state funding for the project. The report says the proposed upgrade is being driven partly by stricter nitrogen requirements at the Bath plant and emerging regulations involving PFOA, PFOS and 1,4-dioxane.
New York River Watch nevertheless argues that conventional pretreatment does not necessarily address the entire spectrum of synthetic chemicals found in leachate.
More than 100 million gallons cannot be reconciled
One of the report’s most striking findings has less to do with chemistry than recordkeeping.
Researchers compared annual reports submitted by landfills with information obtained directly from wastewater treatment plants.
They found significant inconsistencies.
Some landfills reported sending leachate to facilities that said they did not accept it. Others reported volumes that differed from the wastewater plant’s records.
Three facilities collectively reported approximately 106.6 million gallons per year of leachate disposal for which researchers could not identify a corresponding treatment plant that confirmed receiving the material.
The report does not conclude where that leachate actually went.
Instead, the authors argue that the discrepancy demonstrates weaknesses in New York’s tracking system because landfills report their own disposal information while wastewater plants are not routinely required to verify those reports with the state.
That limitation is important when interpreting all of the report’s volume estimates.
Researchers sent FOIL requests to 79 municipalities operating sewage treatment plants and received information from 72 in time for publication. They generally relied on wastewater plant figures when available and used landfill-reported figures in some cases when plants confirmed accepting leachate but did not provide volumes.
Statewide numbers put Finger Lakes issue in perspective
Across New York, 75 active and inactive landfills were identified as sending leachate to municipal sewage treatment plants.
Those plants discharged into 24 New York waterways and one in New Jersey.
The report estimates approximately 167 million gallons per year, or 32% of the statewide total, passed through treatment plants discharging directly into portions of waterways officially classified as drinking water sources.
Those water systems serve more than 2 million New Yorkers in 151 municipalities.
Lake Ontario received the largest estimated amount statewide at 87.5 million gallons annually.
That matters directly to the Finger Lakes region because Rochester and numerous communities along the southern Lake Ontario shoreline depend on the lake for public drinking water.
The Frank E. Van Lare wastewater treatment plant in Monroe County ranked No. 1 among New York plants accepting landfill leachate, receiving an estimated 73 million gallons annually and discharging into Lake Ontario.
High Acres and Mill Seat, both major regional landfills, were among the statewide facilities contributing to the broader leachate system documented by researchers.
Report calls for major change in New York policy
New York River Watch is advocating for the state to stop allowing untreated landfill leachate to be routinely sent through municipal sewage systems.
The organization argues leachate should instead undergo treatment capable of addressing the full range of contaminants before water is returned to the environment.
DEC has already begun addressing several emerging contaminants, including PFOA, PFOS and 1,4-dioxane, and the report notes that the agency has proposed changes to solid waste regulations that could require onsite leachate treatment and disposal at landfills. The Leachate Loophole in New York State.pdfPDF
But the report argues that targeting only a few individual contaminants will not resolve the underlying issue because landfill leachate can contain hundreds — and potentially thousands — of different compounds.
The authors also caution that advanced treatment creates another challenge: once chemicals are removed from water, the concentrated residual waste still has to go somewhere.
For communities across the Finger Lakes, that debate is particularly relevant.
The region contains New York’s highest-volume leachate-producing landfill, several other major municipal and private landfills, treatment plants that have accepted millions of gallons annually, and interconnected lakes and rivers that serve as recreational waters, ecosystems and drinking water supplies.
The report does not establish that those waters are currently unsafe.
What it does document, its authors argue, is a waste-management system in which enormous amounts of chemically complex landfill water routinely move through municipal sewage plants — and a regulatory and reporting structure that may not fully account for what happens to the contaminants after they arrive.
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