Skip to main content
King County logo

Project update

November 2021

Construction Ahead for Mercer Island and Bellevue

cover for storymap showing islands and water with Mount Rainier in the distanceWhy are we doing this work? Where is it happening? How will it impact you? What are we doing to prepare the community for construction? Read our StoryMap to get to know the work area -- and more about the project.

If you are interested in a project update for your community group or neighborhood, please contact Kristine Cramer at 206-477-5415 or

Project description

With over 400 miles of pipes moving wastewater to one of our award-winning treatment plants, King County WTD works hard to maintain our system. We inspect and monitor our regional system and update plans for needed upgrades.

King County WTD needs to replace sewer pipes that serve areas in North Mercer Island, the southwest portion of Bellevue near Enatai Beach, and the Town of Beaux Arts Village. This pipeline carries wastewater from the North Mercer Island Pump Station to the Sweyolocken Pump Station in Bellevue.

nme_construction_reference_guideConstruction Reference Guide.


Project design began in 2016 and will be complete in 2021. Construction is expected to begin in 2021 and extend until 2025.

project timelineView larger version .


Contact us

Contact Kristine Cramer, community services lead at:

 Feedback form

24-hour construction hotline: 206-263-1915

Sign up for email or text updates

To sign up for text alerts, text KING MERCERSEWER to 468-311 for Mercer Island, and KING ENATAISEWER to 468-311 for Enatai. To sign up for email updates, please visit the public involvement page.

Project location

Project pipeline alignment and service area

Back to the capital projects overview map .

Lets Talk Mercer Island!

Construction is expected to start later this year on the Mercer Enatai Sewer Upgrade. The City of Mercer Island and King County are collaborating to ensure Mercer Island residents get timely, accurate construction information. In addition to the County’s website, Let’s Talk Mercer Island will feature the project as it moves into construction.

We will provide monthly updates on Let’s Talk, and we will monitor the site for resident questions and comments. And of course, as always, don’t hesitate to reach out directly with any questions or concerns you might have.

Related information

Regional Wastewater Services Plan

Local municipalities: