FSEC reviews ‘Species 5’ ferruginous-hawk mitigation for Horse Heaven wind-solar project

The Energy Facility Site Evaluation Council on Aug. 20 reviewed recommendations from a Preoperational Technical Advisory Group and the certificate holder about how to apply “Species 5,” the ferruginous‑hawk mitigation measure in the Horse Heaven site certification agreement. FSEC staff and the council were briefed on 45 documented ferruginous‑hawk nest locations within the project lease boundary and on three packages of materials: P‑TAG presentations and minutes, an independent facilitator’s report, and the certificate holder’s recommendation. Staff said the P‑TAG reached consensus on 40 nests but identified five nests (labeled in staff figures as nests B–F) where members disagreed about whether a full 2‑mile buffer must be required around documented nests or whether a smaller 0.6‑mile buffer could apply. Sean Green, FSEC SEPA specialist, summarized the measure’s key terms: primary project components (wind turbines, solar arrays and battery energy storage systems) are prohibited within 0.6 mile of a documented nest; primary components may be sited between 0.6 and 2 miles only if either the nesting site is no longer available or the 2‑mile foraging area is not viable, and then only after the certificate holder develops a species‑specific mitigation and management plan for FSEC approval. Green noted the East BESS is explicitly exempted from Species 5 when co‑located with the East Substation. Certificate holder Scout Clean Energy recommended allowing primary infrastructure in several contested 0.6–2 mile buffers while proposing voluntary exclusion areas and additional mitigation commitments in a hawk mitigation and management plan. Scout’s package said applying full 2‑mile buffers to the five contested nests would reduce the project’s generating capacity by about 348 megawatts (approximately 33% of nameplate capacity), and that the East solar array is critical to delivering roughly 100 megawatts into the east BPA substation. Council members asked clarifying questions about which nest buffers overlap project components, the P‑TAG process and historical nest activity. Council members and staff agreed they needed more time to review the confidential figures and supporting documents. FSEC staff said it will prepare a draft decision document based on today’s discussion, publish it for public comment, and aim to bring a formal vote to the Sept. 17, 2025 council meeting. No formal council decision was taken on Species 5 at the Aug. 20 meeting; staff said they expect to use the P‑TAG materials, the facilitator’s report and the certificate holder’s recommendation to draft a decision document for public comment. The council and staff discussed constraints on public discussion because nest location data are confidential in the Washington Department of Fish and Wildlife Priority Habitat and Species database; staff asked council members to use letter‑labels for nests when discussing them publicly. Staff next steps include preparing a crosswalk memo that describes each figure and each option, identifies which elements can be adopted without amending the site certification agreement, and highlighting voluntary measures that would be memorialized in the mitigation and management plan. The council signaled it will take more time to review the materials and expected a decision process to continue in September.