On Sept. 5, 2025, the Tompkins County Planning, Energy and Environmental Quality Committee received a technical briefing on leachate management for the closed Caswell and Hillview landfills and heard that major on‑site pretreatment is not expected in the near term.

The presentation and ensuing discussion focused on the history of treatment studies, current operational practices, regulatory developments and technology options. Consultants and county staff said trucking leachate to the Ithaca wastewater treatment facility has remained the most economical approach after multiple feasibility studies and pilot tests.

Lou Anne Meyer, an engineering consultant with Barton Le Judas, summarized the long record of studies dating to 1996 and noted a 2016 pilot that evaluated constructed wetlands. "Constructed wetland could not handle total dissolved solids or sodium," Meyer said, citing pilot results that left trucking as the most viable option at the time. Meyer added, "we're keeping a finger on the pulse of technologies and looking at different changes," and said counties are largely waiting on state guidance before investing in on‑site systems.

County staff described current operations: both closed landfills collect leachate in on‑site tanks that are pumped into trucks and hauled to the Ithaca wastewater treatment facility for processing. Leo (Department of Recycling/Materials Management) and Nate Bates (operations lead) said Caswell produces substantially more leachate than Hillview. Bates said the county inspects the sites quarterly and is conducting annual groundwater sampling at the time of the meeting.

The committee heard specific technical and financial constraints. Meyer explained membrane filtration and other engineered treatments require reliable power and higher capital and operating costs. Earlier feasibility work (1996, 2010) narrowed options to constructed wetlands and membrane filtration, and the 2016 pilot found wetlands did not meet all effluent objectives for salts and total dissolved solids. Staff also noted that stricter state effluent requirements since about 2015 could affect the performance or legal acceptability of some on‑site treatments.

Regulatory context: Tompkins County sites are listed in the New York State Inactive Landfill Initiative. The DEC ranks sites by priority; Meyer's slides showed Caswell ranked 29 and Hillview 35 in the 2024 status report. Meyer said both sites already have groundwater monitoring wells and that monitoring can deprioritize sites because they are being managed.

Operational details discussed include tank sizes and volumes: staff reported Hillview has two 30,000‑gallon stainless steel tanks and Caswell has two roughly 8,000‑gallon fiberglass tanks; year‑to‑date volumes cited in the meeting were about 910,000 gallons at Caswell and about 182,000 gallons at Hillview. Staff said peak season runs from October through June and that, during peak weeks, Caswell operations have required hauling seven days a week for several weeks.

Committee members asked about PFAS sampling and whether closed landfills are required to test. Lou Anne Meyer said closed sites are not currently required by regulation to test specifically for PFAS but that DEC rules and priorities are evolving; several speakers noted active facilities are beginning voluntary PFAS testing and that future state rules could require more on‑site or pretreatment action. Committee members also raised the risk that receiving wastewater plants could change their acceptance policies; staff said Ithaca is upgrading its facility and is planning operational changes to avoid large slug loads by ``trickling in'' leachate rather than delivering large pulses.

On infrastructure, staff said the county reprogrammed a capital project window to 2026 for tank repairs and has budgeted a tank replacement in 2027; the department will decide which site to replace first after inspections and tightness testing. Staff also said methane generation at these closed sites is low and not large enough to support viable gas‑capture projects.

The committee did not adopt any new formal policy but directed staff to continue monitoring, to complete sampling and inspections, and to keep the committee informed. Staff said they will continue to track state rulemaking and EPA/state risk assessments and look for pilot opportunities if funding and technology align.