Energy Facility Site Evaluation Council Notice of Opportunity for Public Comment Draft NPDES Permit Renewal for Grays Harbor Energy, LLC Electrical Generating Facility Elma, WA RE: Energy Facility Site Evaluation Council Draft National Pollutant Discharge Elimination System (NPDES) Permit Renewal In compliance with the provisions of The State of Washington Water Pollution Control Law Chapter 90.48 Revised Code of Washington and The Federal Water Pollution Control Act (The Clean Water Act) Title 33 United States Code, Section 1342 et seq. NOTICE is hereby given that the Washington State Energy Facility Site Evaluation Council (EFSEC) has made a tentative determination to issue for public comment on Draft NPDES Permit Renewal Permit WA0024961. The Grays Harbor Energy Center (GH) is located at 401 Keys Rd, Elma WA 98541. Permit compliance will be governed by applicable provisions of Revised Code of Washington (RCW) 80.50, Washington Administrative Code (WAC) 463-76, and WAC 173-220. Grays Harbor Energy, LLC (GH) owns and operates an electricity generation facility located at 401 Keys Road in Elma, Grays Harbor County, Washington. The facility is referred to as the Grays Harbor Energy Center. GH is capable of generating up to 662.4 megawatts of electricity from a combined-cycle power plant comprised of two combustion turbines, each equipped with a duct burner and heat recovery steam generator and a single steam turbine and bank of cooling towers shared in common. GH also operates an auxiliary boiler, a diesel emergency generator, and an emergency fire water pump. Commercial operations of GH began on April 25, 2008. GH treats wastewater generated onsite and discharges it to the Chehalis River. EFSEC issued the previous permit for this facility on June 19, 2019, and made it effective on July 1, 2019. The proposed permit retains the effluent limits for temperature, total suspended solids (TSS), oil and grease (O&G), chromium, and pH; replaces free available chlorine limit with total residual chlorine limit; reduces chromium monitoring frequency; and removes turbidity from annual monitoring. This fact sheet complies with WAC 463-76-034 and WAC 173-220-060 which requires EFSEC to prepare a draft permit and accompanying fact sheet for public evaluation before issuing a NPDES permit. EFSEC makes the draft permit and fact sheet available for public review and comment at least thirty (30) days before issuing the final permit. Copies of the fact sheet and draft permit for Grays Harbor Energy Center, NPDES permit WA0024961, are available for public review and comment. What is EFSEC proposing to do? EFSEC is proposing to issue public comments due 30 days prior to EFSEC issuing NPDES Permit. How can you review the proposed permits? https://www.efsec.wa.gov/energy-facilities/grays-harbor-energy-centerEFSEC 621 Woodland Square Loop PO Box 43172 Lacey, WA 98503-3172 You may comment on the proposed permit and supporting documents from Monday, September 29, 2025 through close of business on Tuesday October 28, 2025 on the EFSEC website at https://comments.efsec.wa.gov or in writing to the EFSEC office (see address above). Can a decision be appealed? Yes. This Order is subject to review pursuant to: WAC 463-76-063 and WAC 173-220-225. For more information about the Draft NPDES, contact: EFSEC:Sara Randolph (360) 485-1594 or sara.randolph@efsec.wa.gov To request ADA accommodation or materials in a format for the visually impaired, or a translated version of the documents, contact the EFSEC office at (360) 664-1345. IPL0277083 Sep 28 2025