Consultants present terminal HVAC and geothermal options; treating or relocating geothermal wells discussed as PFAS remedy

At the Feb. 11 meeting, consultants presented high‑level options for the terminal heating and cooling system and discussed how those choices intersect with PFAS remediation options.

The staff presentation outlined four broad options: (1) an adiabatic (evaporative) or air‑cooled dry cooler with electric or propane boiler backup that would retain much of the existing equipment; (2) electric air‑source heat pumps for a modern, zoned solution; (3) a closed‑loop geothermal field requiring a new well field and manifold; and (4) retaining the existing open‑loop geothermal well system but adding groundwater treatment to prevent spread of contamination. Consultants provided ballpark capital‑cost guidance for the options and emphasized that retaining and treating the existing open‑loop system — or moving extraction/injection points — could both reduce groundwater migration and produce heat‑exchange benefits for the terminal.

Jim Soukup and consultant Rich Lasdun both stressed that PFAS remedial work in the Phase 3 report will likely require some active groundwater control in the Runway‑15 approach area; that regulatory context strengthens the argument for treating or relocating geothermal wells rather than simply abandoning them. One consultant said a treated, relocated open‑loop system could accelerate contaminant capture and reduce off‑site migration while preserving energy performance benefits for the terminal. Commissioners urged detailed load data, phasing plans and cost estimates to inform a preferred option; consultants agreed to provide those figures and to coordinate geothermal options with the Phase 3 remedial analysis and the terminal optimization schedule.

No formal commission decision was taken at the meeting; staff and consultants will refine load estimates, cost models and integration plans and return at a subsequent meeting.