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Project update

January 15, 2020

King County will host open houses on January 29 and 30 to share the latest information about the North Mercer Island/Enatai Sewer Upgrade Project.

There will be no formal presentation. Stop by anytime during the open house. Click here for details about the open house.

People of all abilities are welcome at these meetings. Please let us know how we can welcome you. We know there is a steep ramp from the Mercer Slough Environmental Education Center parking lot to the facility – we would be happy to work with you in advance to ensure the open house is accessible to all.

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

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.


Contact us

Contact Kristine Cramer, community services lead at:


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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.

Project area mapView larger version . December 2018


Project design began in 2016 and will be complete in early 2020. Construction is expected to begin in 2020 and extend until 2024.

project timeline View larger version .

Project location


Back to the capital projects overview map .

Related information

Regional Wastewater Services Plan

Local municipalities: