STATE ENVIRONMENTAL PROTECTION ACT DETERMINATION OF NONSIGNIFICANCE Lakehaven Water and Sewer District Comprehensive Wastewater System Plan Lakehaven Water and Sewer District 32716A 1st Ave S Federal Way, WA 98003 DATE OF ISSUANCE: May 13, 2026 PROPONENT / LEAD AGENCY: Lakehaven Water and Sewer District Description of proposal: The Lakehaven Water and Sewer District (District) is updating the Comprehensive Wastewater System Plan (Comp Plan), which is an overarching plan that complies with the applicable federal, state, county and local regulatory requirements and will guide Lakehaven's sewer utility in the future. The Comp Plan documents the District's existing wastewater collection and treatment systems, evaluates their performance under current and projected conditions, and provides a coordinated program of capital and operational improvements to support reliable, cost-effective service through the 6-year, 20-year, and build-out planning horizons. The plan describes the sewer service area, existing collection and treatment system, and outlines policies, goals, and plans that will guide future expansion and improvements. Location of proposal: The Comprehensive Plan covers the Lakehaven sewer service area that covers parts of the cities of Federal Way, Auburn, Des Moines, Kent, Milton, Edgewood, Pacific, and Unincorporated King and Pierce County. THRESHOLD DETERMINATION: The lead agency for this proposal has determined that it does not have a probable significant adverse impact on the environment. An environmental impact statement is not required under RCW 43.21C.030(2)(c). This decision was made after review of a completed environmental checklist and other information on file with the lead agency. This information is available to the public on request. WRITTEN COMMENTS AND APPEALS: This Determination of Non-significance (DNS) is issued under the Lakehaven Water and Sewer District Resolution 2019-1320 and WAC 197-11-340(2). The lead agency (Lakehaven Water and Sewer District) will not act on this proposal for 14 days from the date of this DNS or date of legal notice, whichever is later. Comments must be submitted to the District by 4:30 pm on June 4, 2026. Unless modified by the District, this determination will become final following the comment deadline. Any person aggrieved of the District's final determination may file an appeal, along with the appropriate filing fee, within 14 days of date of the determination or of the date whenever any required notice is made, whichever is later; provided that if there are any state statutory requirements for appeals specified therein, such requirements shall control. Responsible official: John Bowman Position/Title: General Manager Phone: (253) 941-1516 Address: 31627A 1st Ave S., Federal Way, WA 98003 Publication Date: May 20, 2026; and May 27, 2026 Comment Deadline: June 4, 2026 Appeal Deadline: June 4, 2026 Staff Contact: Jai Carter, P.E. Senior Project Engineer Phone: (253) 946-5403 Email: JCarter@Lakehavenwsd.gov IPL0340872 May 20,27 2026