Committee raises liability and decommissioning concerns for proposed ~130‑MW battery project, seeks coordinated county action

A committee member presented research on risk-mitigation gaps for large battery energy storage systems (BESS) and urged the committee to develop the city’s approach to influencing King County policy.

The presenter said King County’s commercial general-liability cap of $1 million is insufficient for potentially catastrophic incidents involving large BESS or data-center projects and noted BESS sites can be sizable (the presenter referenced "130 megawws" in the materials). The presenter cited examples from other states where energy-related fires produced hundreds of millions in losses and said that, because developers can become insolvent, tools such as letters of credit, decommissioning bonds or higher insurance minimums are needed to ensure cleanup and response costs do not fall on local taxpayers.

Council Member Tesman said the council’s role could be to lead a regional advocacy effort to persuade county legislators and that the city should favor protections for residents when tradeoffs arise. Tesman also asked staff to investigate industry best practices on setbacks for BESS projects.

Council Member Cotton emphasized emergency-response funding, equipment and training needs, and proposed decommissioning protections in the range of $15 million (as a planning figure), saying a letter of credit or bond is the most reliable instrument if a developer fails. Cotton cited wildfire and evacuation-route concerns for neighborhoods near the proposed site.

Mayor Mayhew clarified the limits of city influence on county legislation: “there is no pathway by which a city can introduce legislation at the county level,” and recommended direct engagement with county council members and regional partnerships. Staff and council members agreed a lone city letter to the county would have limited effect unless it was part of a coordinated multi-city effort and that the city could separately pursue local ordinances or annexation conditions if the developer seeks local approvals.

Next steps: committee members agreed to bring the presenter’s research to the upcoming workgroup meeting, to coordinate with staff and legal counsel on possible model language (resolutions or ordinance options), and to plan outreach to county legislators and other cities to build a joint record for King County hearings.