PIERCE COUNTY NOTICE OF DETERMINATION OF NONSIGNIFICANCE Environmental Checklist: Pierce County Parks Hypolimnetic Oxygenation System Application: 1064825 Notice is hereby provided in accordance with PCC, Chapter 18.80 and Section 18D.40.050, and WAC 197-11-510 that Pierce County has issued a Determination of Nonsignificance (DNS) on the following proposal: Pierce County SWM proposes to build a hypolimnetic oxygenation system to improve water quality and address persistent toxic cyanobacteria blooms in Spanaway Lake. The project is an environmental enhancement action designed to restore dissolved oxygen levels in the lakes lower water column. 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 March 24, 2026. Comments must be submitted by close of business on March 23, 2026. An appeal of this determination must be filed no later than April 6, 2026. Appeal Submittal Information can be found at: Administrative Appeals | Pierce County, WA - Official Website IPL0321180 Mar 11 2026