Construction History

Completed Projects

The District is committed to providing affordable and reliable service today and into the future. A key component of that is managing an efficient and effective capital program. The District invests capital into projects which add value to the community and customers. This includes new infrastructure projects which increase the capacity and reach of the collection system, allowing for new businesses and residents to connect. It also includes investing in the restoration and replacement of existing infrastructure to extend the useful life and increase the reliability of existing assets as they naturally age. Some examples of recently completed capital projects include the Discovery Corridor Wastewater Transmission System, a project of regional significance, and the Highway 99 Sewer South project, both of which are highlighted below. The projects highlighted on this page are reflective of the District’s history and commitment to investing in the collection system.

Discovery Corridor Wastewater Transmission System – Phase 1

After more than a decade of planning and two years of construction, this major project connecting Ridgefield junction to the Salmon Creek Treatment Plant has been successfully completed on time and on budget.

The Discovery Corridor Wastewater Transmission System (DCWTS) is a 20 year, multi-phase program to provide for the conveyance of wastewater from the Ridgefield Urban Growth Area to the Salmon Creek Wastewater Management System (SCWMS).

Phase 1 of the project, which includes a new wastewater conveyance pipeline to connect the City of Ridgefield’s Interstate 5 Junction area to the Salmon Creek Treatment Plant, has been successfully completed. Construction on the pipeline began in June 2014 and was completed late 2015, with system commissioning extending into early 2016. For more information about this exciting project, click here.

Construction Window June 2014 – December 2016
Contractor Tapani Inc.
Total Project Cost $29 M
Capital Improvement Yes
Restoration & Replacement No
Location Ridgefield – Salmon Creek

Highway 99 Sewer South

This project consisted of replacing a sanitary sewer pipe along Highway 99, between NE 63rd Street and NE 78th Street, as part of a proactive effort to keep our sewer system operating safely and efficiently. For more information about this project, click here.

Construction Window May – October 2016
Contractor Nutter Corporation
Total Project Cost $2.6 M
Capital Improvement No
Restoration & Replacement Yes
Location Hwy 99: NE 63rd St – NE 78th St

Cougar Creek Sewer Rehabilitation

The District performed proactive maintenance and rehabilitation of the existing sewer line in Cougar Canyon between NW 99th Street and NW 115th Court. The project was completed in Fall 2022.

Construction Window Spring 2021-Fall 2022
Location Cougar Canyon

Campus Facilities Master Plan

After more than 20 years at its current location, the Board of Commissioners of Clark Regional Wastewater District (District) expanded facilities on its campus to house its growing operations for the next 20 years. The improvements provide the District with the facilities necessary to meet the increasing demand for District services and improve the resiliency of District operations. Construction was completed in 2022.

Construction Window 2019 – 2022
Location District Campus

NE 20th Avenue Sewer Pipeline

The NE 20th Avenue Sewer Pipeline project installed just over a half mile of new 30-inch diameter sewer pipe in NE 20th Avenue between NE 139th Street and NE 154th Street.

This project supports planned future growth and economic development in the District’s service area. This investment in new sewer infrastructure provides continued reliable and effective service for our customers for at least another 50 years, while at the same time protecting public health and the environment.

Construction Window May 2020 – June 2023
Location NE 20th Avenue between NE 139th Street and NE 154th Street.

Mt Vista Trunk Upgrade

This project will upgrade existing sewer main lines and provide increased capacity in support of economic development and jobs creation.

Construction Window Summer 2024
Traffic Impacts Moderate
Contractor Nutter
Capital Improvement Yes
Restoration & Replacement No
Location Vicinity of Salmon Creek Avenue and NW WSU Entrance Road

2024 Lining

This project will extend the useful life of defective gravity sewer assets using a trenchless technology called cured-in-place-pipe or CIPP.

Construction Window Summer – Fall 2024
Traffic Impacts Moderate
Contractor Insituform
Capital Improvement No
Restoration & Replacement Yes
Location Varies

Whipple Creek West Pump Station and Force Main

The Developer of the Trails at Whipple Creek Subdivision will install a District regional pump station and force main as part of the development project.

Construction Window Winter 2023/2024 – Summer 2024
Traffic Impacts Low
Contractor Rotschy
Capital Improvement Yes
Restoration & Replacement No
Location NW 11th Ave and NW 154th St

Whipple Creek North Pump Station Upgrade

This project will upgrade an existing pump station and provide increased capacity to serve the NE 179th Street Corridor in support of economic development and jobs creation.

Construction Window Spring – Summer 2024
Traffic Impacts Low
Contractor Nutter
Capital Improvement Yes
Restoration & Replacement Yes
Location Vicinity of NE 179th Street and 22nd Avenue

South Junction Trunk Sewer Upgrade

This project upgraded an existing sewer gravity main to support economic development in the Ridgefield Junction area. In 2024, the project will construct a bark chip pedestrian trail on behalf of the City of Ridgefield and conduct storm facility maintenance work on behalf of the Port of Ridgefield.

Construction Window Spring – Summer 2024
Traffic Impacts Low
Contractor North Cascade
Capital Improvement Yes
Restoration & Replacement No
Location Vicinity of S 56th Place & S Timm Rd (Ridgefield)

Knollridge South and West Pump Station Replacements

This project will replace two existing pump stations with new facilities that meet current District design standards.

Construction Window Summer 2024
Traffic Impacts Low
Contractor Rotschy, Inc.
Capital Improvement No
Restoration & Replacement Yes
Location Cul-de-sacs at NE 127th Cir & NE 6th Ct