Skip Navigation

North Mercer/Enatai Sewer Upgrade Project

Online open house live until March 31, 2020

King County is upgrading three miles of sewer pipeline from the North Mercer Pump Station on Mercer Island to the Sweyolocken Pump Station in Bellevue. In addition to the new sewer pipeline, King County will upgrade the County’s North Mercer Pump Station, as well as the City of Mercer Island’s Lift Station 11 at Fruitland Landing.

Construction is expected to begin in 2021 and be complete in 2024. When complete the new pipe and upgraded pump station will provide safe, reliable service for 50 years or more. We are committed to keeping you in informed along the way so you know what to expect before and during construction. 

Project area map

Use the plus and minus buttons in the upper left corner of the map to zoom in or out.

Project design phase wrapping up

King County continues to make progress on the design for the North Mercer/Enatai Sewer Upgrade Project. We’ve been working closely with local jurisdictions, including the City of Mercer Island and City of Bellevue, and partner agencies to get feedback on the final design. We’ve also been working closely with you to better understand your priorities and keep you informed of project updates.

Over the past year, we have:   

  • Completed the State Environmental Policy Act (SEPA) review process
  • Made draft plans for how we’ll replace trails, repave streets and sidewalks, and replant trees and shrubs after construction
  • Made preliminary plans for managing traffic along the I-90 Trail, North Mercer Way and other local streets when construction starts
  • Began acquiring permits from the City of Mercer Island, City of Bellevue, and state and federal agencies
  • Continued conversations with you to share the latest project information and incorporate your feedback in our design wherever possible

Please use the tabs in the menu above or continue below to learn more about this year’s progress and what to expect before and during construction. We also invite you to provide feedback on our project communications and reach out to us with any questions or concerns.