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Project update

January 2018

A peek inside the project

A ladder leans against a concrete wall the bottom of a deep vault. A hole with a gate and an open and closing mechanism is located in the wall near the bottom.Looking down at the influent slide gate. This gate can be closed to stop wastewater from flowing into the storage tank when it is full.

Three workers stand near a large container. Pieces of pipe lay on the ground nearby.Once hooked up, this unit will provide odor control for the storage tank.

November 2017 Project update : A look back at the progress made and at what’s next.

New sewer pipe construction complete!

In June 2017, King County’s contractor completed their work and put into operation the first of two project elements designed to reduce CSOs. We have completed the installation of a new sewer pipe that will be used to divert, or redirect, sewage and stormwater from a pipeline in Rainier Avenue that gets full during storms to another pipeline in Bayview that goes under Beacon Hill and has room to carry more flow. This work was done near the intersection of Rainier Ave. S. and S. Bayview St. We have also repaved the inside lanes of Rainier Avenue South and restored and returned the worksite to the property owner.

Continued construction activity at the tank site

Contractors are making progress on the above-ground building that will hold the electrical controls and standby generator needed to run the facility.



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Contact Caryn Sengupta at:


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To learn more about how we installed pipe under Rainier Ave. S. without having to close the road for long periods of time, watch this video on microtunneling.

Project description

This project will keep sewage and stormwater out of the Duwamish River. A new sewer pipe will be installed near the intersection of Rainier Avenue South and South Bayview Street to send sewage and stormwater from a pipe that gets full during storms to another pipe that has more room. 

A storage tank at the intersection of South Hanford Street and South 27th Avenue will catch any remaining extra sewage and stormwater to keep sewage and stormwater out of the Duwamish River. 

New and reused pipe at S. Bayview St.New and reused pipe at South Bayview Street (  , May 2014)

new storage tank at S. Hanford St.Underground storage tank at South Hanford Street (  , May 2015)

Project schedule

Project scheduleProject schedule (  , May 2015)