PIERCE COUNTY NOTICE OF DETERMINATION OF NONSIGNIFICANCE Pierce County Stormwater and Site Development Manual 2026 Update Proponent: Pierce County Planning & Public Works-Surface Water Management Application: 1060420 Notice is hereby provided in accordance with WAC 197-11 that Pierce County has issued a Determination of Nonsignificance (DNS) on the following proposal: The proposal is to amend portions of the Pierce County Stormwater Management Manual and Title 17A "Construction and Infrastructure Regulations – Site Development and Stormwater to: • Satisfy obligations contained within the Phase 1 Municipal Stormwater Permit issued by the Washington State Department of Ecology. The Phase 1 Municipal Stormwater Permit (MSP) is part of the National Pollutant Discharge Elimination System (NPDES). The Phase 1 MSP went into effect August 1, 2024, and remains in effect through July 31, 2029. The Phase 1 MSP requires updates to the County's current Stormwater Management and Site Development Manual, and Title 17A Construction and Infrastructure Regulations – Site Development and Stormwater Management. • Clarify and streamline stormwater management requirements for new development and re-development in unincorporated Pierce County Pierce County, acting as lead agency, has determined that the proposal will not result in significant adverse impacts on the environment. An Environmental Impact Statement (EIS) will not be required. This decision was made after the review of a completed environmental checklist and other information on file. This information is available to the public on request. This DNS is issued under WAC 197-11-340. Pierce County may not act on this proposal prior to February 13, 2026. Comments must be submitted by close of business on February 12, 2026. The Responsible Official has issued this Determination of Nonsignificance for a nonproject action, which may be appealed under the State Environmental Policy Act (SEPA). RCW 43.21C.075. In some cases, the SEPA appeal must be combined with any appeal of the underlying governmental action pursuant to RCW 43.21C.075(2)(a). SEPA appeals associated with legislative actions taken by the Pierce County Council pursuant to the requirements of the Growth Management Act or Shoreline Management Act must be appealed to the Growth Management Hearings Board. PCC 1.22.080.B.1.k and RCW 36.70A.280(1)(a). The appeal must be filed with the Growth Management Hearings Board within 60 days following publication in the County paper of record for the underlying governmental action pursuant to RCW 36.70.290(2) and WAC 242-03-200. Review Practicing Before the Growth Management Hearings Board Handbook for additional information on the appeal process. IPL0309915 Jan 31 2026