Tualatin Interceptor and Siphon Improvement
Tualatin Interceptor and Siphon Renovation / PortlandOR
What does it take to install pipeline beneath a river?

Construction on West Durham Basin Improvement Program projects began in summer 2018. Initial projects will replace the aging interceptor – the pipe infrastructure that helps control flow – constructed in 1974, with more resilient and larger pipes. This upgrade will provide a pipeline that can move 20 million gallons of wastewater each day and will handle capacity through 2040.

Clean Water Services is investing nearly $70M into this 10-year sanitary sewer program to support growth in areas of Beaverton, Tigard, Tualatin, Sherwood, unincorporated Washington County, and King City, including nearby urban reserves.

Current projects include:

  • Tualatin Interceptor and Siphon Improvements
  • Roy Rogers Road Gravity Sewer Pipe Installation

  • River Terrace North Second Pressurized Sewer Pipe Installation

  • River Terrace South Pump Station and Pressurized Sewer Pipe Installation

  • Bull Mountain Trunk Improvements Project 

The Upper Tualatin Interceptor (UT) serves the cities of Tualatin, Tigard, King City, and Sherwood and flows into the Durham Wastewater Treatment Plant. The UT must be replaced in order to meet the long term capacity needs in the area. This project will be constructed in two phases to minimize costs and accelerate the construction schedule.

Phase 1 – Scheduled from June 2018 through December 2018:

  • Construction activities include installing pipe, constructing trenchless crossing of the Tualatin, surface restoration, and vegetation enhancement within the vicinity of Hwy 99 and SW Hazelbrook Road in Tualatin. Residents should anticipate increased truck traffic into/out of the work zone, closure of Hwy 99 boat ramp on Tualatin (June through August).

Phase 2 – Scheduled from May 2019 through February 2020:

  • Construction will occur south of the Tualatin River and to the west. Residents should anticipate increased truck traffic into/out of the work zone, construction through Jurgens Park.


Facts And Figures

Clean Water Services

10,000 linear feet of sewer pipeline in varying sizes from 36" to 66"


Delivery Methods

Progressive Design-Build

The Team