Geothermal feasibility study finds district system limited by site conditions; test borehole and tax-credit potential next steps

Tompkins County staff briefed the Downtown Facility Special Committee on a geothermal district feasibility study on Sept. 2, 2025, reporting that site‑specific constraints limit the scope of a shared geothermal loop but that a partial district serving the new Center of Government and the old jail is technically possible and may be economically attractive with federal incentives.

Terry (project consultant) said a pressured shallow aquifer about 200 feet below grade limits borehole depth in the area; because of that, the team conservatively estimated drillable depth at roughly 175 feet in this block. He said "the first challenge...is that Ithaca sits on a shallow water aquifer...if you penetrate that then you start to run into complexities." The study concluded that a field sized to serve the center building and old jail is feasible but that the main courthouse and off‑block neighbors could not be accommodated without additional drilling or alternate locations.

Nut graf: The study found enough capacity to cover much of the new center building and the adjacent old jail, but site geology and surface constraints (limited open ground on the block) prevent a full district that includes the main courthouse and nearby properties; the team will drill a test borehole to verify conservative assumptions and will examine options to place boreholes beneath the new building footprint.

Cost and incentives: The consultant reported a preliminary capital estimate of about $5.6 million for boreholes, connections and piping to serve several buildings; that number excluded terminal units (the in‑space heat pumps and controls). Terry said the recent federal legislation preserved tax incentives for commercial geothermal, and the project could be eligible for a direct‑pay tax credit of roughly one‑third of eligible costs if structured appropriately. "There would be roughly the potential to receive up to about 33% as a tax credit through the direct pay program," Terry said.

Next steps and risks: The team plans a geotechnical test borehole to 175 feet to validate the report's assumptions and explore directional drilling under the new building as an option to increase field capacity. Consultants cautioned that placing boreholes under buildings increases long‑term complexity but is becoming more common; if a borehole fails in future, drilling a replacement borehole is usually more cost‑effective than repairing it. The team also noted changes to state and federal funding programs and that the county's current square footage may or may not qualify for certain state engineering‑support programs.

Ending: Committee members asked about options if the courthouse is excluded and expressed interest in proceeding with whatever geothermal capacity is reasonably feasible now; staff and consultants will pursue the test borehole, continue engineering coordination with Holt and Tetra Tech, and explore grant and tax‑credit pathways.