Thurston County commissioners hear appeal of Convergent Energy battery storage permit

The Thurston County Board of County Commissioners heard oral argument on Wednesday over an appeal of a hearing examiner’s March 9, 2026, approval of a special use permit for a 5.4-megawatt battery energy storage system proposed by Convergent Energy and Power at 7505 183rd Avenue SW in Rochester.

The appellants, identified in the record as Brian and Tamara Haight, asked the board to reverse the examiner’s decision, saying county procedures and code interpretations were flawed and that the record lacks a complete, site-specific emergency response plan (ERP) and hazard mitigation analysis. “No application for special use should be approved unless a specific finding is made that it is appropriate for the location,” an appellant told the commissioners, citing Thurston County code in their argument.

Convergent’s counsel, Reuben Schultz, urged the board to uphold the examiner, saying the decision is supported by a substantial administrative record that includes technical reports on groundwater, traffic, noise, geology and fire risk and a final MDNS that was not appealed. Schultz said the selected 11-acre parcel would host a facility with a development footprint of about 16,000 square feet (roughly 3% of the site), setbacks larger than code minimums, and proximity to an existing substation, and that the examiner attached 25 conditions to the approval.

Why it matters: the dispute turns on two linked questions—whether the county properly classified the proposed use under its development code and whether the administrative record contains adequate, site-specific safety plans and mitigation to protect neighboring properties and emergency responders. Appellants argued the RCC (Rural Commercial Center) zoning is intended to serve local rural communities, not regional grid needs, and that a private, for-profit facility with the record as presented poses undue burdens on local fire services and groundwater.

Appellants’ concerns and evidence Appellants told the board the examiner and staff failed to produce an appealable determination of the facility’s use classification, citing Thurston County code as requiring a formal determination that the project be treated as a major energy generation/transmission facility. They emphasized safety gaps: the record, they said, contains an incomplete ERP and a draft, non-site-specific plan lacking contact information, response times for hazmat teams, and monitoring protocols for hydrogen fluoride. Appellants noted the nearest regional hazmat team is at Camp Murray and said response could take about two hours; they also cited instances of fires at Convergent facilities and warned of toxic off-gassing and potential groundwater contamination in an area where the water table sits shallowly.

“The examiner concluded [on reconsideration] that an ERP, in coordination with the fire chief, was not needed prior to special use permit approval,” one appellant said, adding that the reconsideration did not explain the reversal and did not engage with new evidence submitted by members of the public.

Applicant’s defense and the examiner’s approach Schultz told commissioners the examiner conducted two hearings, reviewed extensive exhibits and testimony, and issued a detailed 45-page decision with 25 conditions. He said the MDNS had concluded no significant unmitigated impacts and that the examiner appropriately relied on technical experts, county staff recommendations and the record. On fire and hazmat concerns, Schultz said modern equipment choices (he cited LFP—lithium iron phosphate—chemistry) and required conditions reduce risks, and that final technical review and certification is the fire marshal’s responsibility at later permitting stages. “This is not a rubber stamp,” Schultz said of the process, adding that the examiner specifically required equipment- and site-specific isolation zones and an ERP to be completed as conditions of approval.

Commissioner questions focused heavily on two issues: whether the West Thurston Regional Fire Authority had established an evidentiary showing of an “undue burden” on local services, and whether the applicant’s site-selection documentation met the code’s requirement for consideration of alternatives. Schultz said the record includes staff review and exhibits documenting screening of more than 150 parcels down to a small set and that staff and the examiner reasonably concluded the showing met legal standards; he also pointed to potential mitigations, including impact fees and equipment/training coordination with the fire authority.

Outstanding technical and legal points Commissioners pressed whether the battery system fits the county definitions for a major energy transmission/generation facility and what weight the comprehensive plan’s RCC purpose should carry when zoning permits a use. Appellants said the RCC designation exists to preserve sites for local services and that allowing privately owned battery facilities in those parcels undercuts rural community needs; the applicant argued the code permits the use and the examiner’s interpretation was within staff and hearing-examiner expertise.

What happens next The board closed oral argument and announced it will issue a written decision within a week, then moved into a closed session to deliberate under RCW 42.31.40(2). No vote or final action was taken at the hearing.

The record in this case includes the hearing examiner’s decision (dated 03/09/2026), the appellants’ appeal (filed 03/19/2026), technical exhibits cited by staff and the examiner, and public comments submitted to the county.