State Environmental Policy Act (SEPA) Determination of Non-Significance (DNS) issued for upcoming King County Sewer Upgrade Project
King County is planning to upgrade the Elliott West Wet Weather Treatment Station (EWWTS), located at 601 Elliott Ave W. Like many cities around the country, older parts of sewer system use the same set of pipes to carry both sewage and stormwater. When the system is overwhelmed, it is designed to overflow into waterways. This is called a Combined Sewer Overflow (CSO). EWWTS is a CSO facility that provides partial treatment to sewage and stormwater during large storms to reduce untreated overflows of combined wastewater into Elliott Bay.
EWWTS needs an upgrade to ensure compliance with stricter environmental regulations, meet the demands of a growing population, and handle a changing climate. Upgrades will include expansion of the existing facility to the property to the south and decommissioning the existing dechlorination system at the Denny Way Regulator Station (3155 Alaskan Way). If it is determined that additional improvements are necessary to ensure water quality compliance, the Elliott West CSO Outfall may also be modified.
To learn more about the project, visit: www.kingcounty.gov/elliottwestupgrade.
Environmental Review
King County must perform an environmental review as required by the State Environmental Policy Act (SEPA). The SEPA review process involves evaluating how the project will affect the environment.
King County issued a SEPA Determination of Non-significance (DNS) for this project on June 20, 2025. This determination means the County’s SEPA review found that the project will not have significant adverse impacts to the environment. The determination will be reviewed by the Washington State Department of Ecology.
To view the project’s SEPA Environmental Checklist, visit: https://kingcounty.gov/wtdenvreview
For more information about environmental review, please contact Jessica Conquest at: (206) 263-3721 or jconquest@kingcounty.gov.
King County will accept public comment on the SEPA DNS through July 7, 2025.
Comments should be submitted via regular mail to:
Jacob Sheppard, Supervisor, Environmental Planning
King County Wastewater Treatment Division
201 S Jackson Street, MS: KSC-NR-6200
Seattle, WA 98104-3855
Shape the future of clean water
Your voice matters as we plan the future of clean water for our Puget Sound region. King County’s Vision for Clean Water sets our clean water goals for our regional wastewater system for the next 75 years.
|
