HydroStore outlines timeline, water and permitting questions for Lewis County energy storage proposal

HydroStore representatives told Lewis County officials at a public meeting that a proposed 500-megawatt underground compressed-air energy storage project in the county depends on the results of a New York State procurement process and multiple state and local permits.

The project is tied closely to a New York State Energy Research and Development Authority (NYSERDA) procurement. "If we don't have a commercial pathway with NYSERDA, then we really don't have a project at all," said Dean, a HydroStore representative. Company staff said the state is expected to issue an RFP (request for proposals) for long-duration storage technologies and that the window for that procurement will determine whether HydroStore advances to the costly site-testing stage.

Why it matters: The proposal would require large, one-time site preparations and a single-time water fill, subsurface drilling and local approvals. County officials repeatedly raised questions about potential impacts on municipal wells, blasting and construction noise, and requested the company fund or allow independent technical review. Those items figure into whether the towns and county will support permitting and host-community conditions.

What HydroStore told the county - Procurement dependency and schedule: HydroStore said New York officials will publish an RFP for long-duration storage technology that company staff expect to cover up to about 600 megawatts; the company's proposed unit is roughly 500 megawatts. The company expects a draft RFP for comment within weeks, with an official RFP required by midyear and RFP results potentially by October. HydroStore said it would aim to file a proposal around July if the RFP draft and final language look favorable. - Phase 1 work and borehole testing: HydroStore said it began an early permitting and site-evaluation phase and has hired outside experts to support DEC (state Department of Environmental Conservation) permitting and a borehole program. The company described the next substantive test as a borehole that could extend about 2,500 feet and cost on the order of a couple million dollars; HydroStore said its board must approve that expenditure once the company has sufficient confidence the procurement will support moving forward. - Water and reservoir plans: HydroStore said the facility would need a one-time fill on the order of 1,100 acre-feet of water for the reservoir attached to the system. Company representatives described a typical reservoir occupying tens of acres and around 10 feet deep as an example; they said the system is a closed loop and that, in operation, the project can generate some reclaimed water. The company said it is evaluating whether water would be sourced on-site or brought in from outside sources and acknowledged the towns' concerns about municipal well impacts. - Cavern, shafts and above-ground equipment: HydroStore described the underground storage as a network of connected hard-rock caverns (characterized by the company as a set of tubes or “straws”), with shafts and lined casings connecting a surface reservoir to the caverns. Shaft diameters have not been finalized but were described as in the range of roughly 8–10 feet; certain above-ground tanks that store heat and working fluid could reach about 100 feet in height at the tallest points. - Construction, blasting and noise: The company said blasting techniques, vibration and noise-control methods will be site-specific and subject to DEC and local permit limits. Company staff said blasting would follow regulatory setbacks (they stated a 500-foot setback is required) and that work underground would not be audible at the surface. For operational noise, HydroStore cited a prior site study where fence-line noise during operation measured roughly 50 decibels, which the company described as comparable to or quieter than a normal conversation. - Interconnection and cost risks: HydroStore warned that the interconnection study and associated system upgrades — performed through New York ISO processes and influenced by recent federal interconnection rules — could impose large costs that might make a project uneconomical even after permitting and site testing are complete.

Concerns raised by officials and residents County and town officials asked directly about the risk to nearby private and municipal water wells, the scale and timing of blasting and whether the towns could require more restrictive blasting hours than state permits. Several officials asked whether towns could use intervener funds (local legal/technical funding available in some state processes) to hire independent engineers and attorneys to review permit materials; HydroStore said such discussions were appropriate after the RFP result and when a site selection was more definite.

Officials also pressed HydroStore on community outreach. County staff noted the administration is compiling questions and written answers for public posting, and HydroStore said it would provide materials, photos of comparable projects and consider organizing site visits to operating facilities to help officials and residents evaluate operations.

Company constraints and next steps HydroStore said it is moving multiple items in parallel — permitting, DEC reviews, RFP responses, and interconnection work — but that the company is a relatively small development team and must balance early expenditures against the probability of selection in the procurement. The company said it will likely perform a borehole at one preferred site, then decide whether to test others based on results and permitting outcomes. HydroStore said it will notify the towns before conducting borehole work and is prepared to discuss additional town-imposed conditions, though such conditions could affect costs and schedules.

The company offered to return with more detailed technical material and support local requests for independent review once the RFP and DEC permitting steps clarify the project's path.