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Project update

July 16, 2018

In-water fieldwork along Bellevue shoreline starting July 18

During the summer of 2018, King County Wastewater Treatment Division (WTD) will continue fieldwork to inform design of a sewer upgrade project in Mercer Island and Bellevue. As early as Wednesday, July 18, crews will begin inspecting parts of the existing sewer pipe along the Enatai shoreline between Enatai Beach Park and the Mercer Slough. This work is expected to last up to two weeks.

Later this month, crews will return to inspect maintenance holes just off the shoreline and perform in-water survey work along the Enatai and Mercer Island shorelines. This work will help our team understand the condition of the project area and features near the shoreline. King County will notify property owners in cases where maintenance holes are located on private property.

For more information about work locations and what to expect, see the latest project update .

Crew members working from a dive boat that powers a hose used to expose underwater structuresCrew members working from a dive boat that powers a hose used to expose underwater structures.

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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.


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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.

1701_NME-final-pipeline-route_700View larger version. July 2017


Project design will begin in 2016. Construction is expected to begin in 2019 and extend until 2022.

Project TimelineClick to view larger version .

Project location


Back to the capital projects overview map .

Related information

Regional Wastewater Services Plan

Local municipalities: