Discovery Corridor Wastewater Transmission System Phase 2
Population in our service area is growing, so we’re starting a second construction phase to increase capacity. We’re splitting the work into two projects. Neither will interrupt your sewer service.
- Phase 2A (winter 2024 through fall 2025) will have only brief traffic interruptions to stage large equipment, including on North Royle Road north of Pioneer Street.
- Phase 2B (winter 2026 through fall 2026) will affect traffic and business access along NE 20th Avenue and at its intersections with NE 134th Street and NE 129th Street. We’ll be in touch with affected businesses and residents to reduce the impacts.
Sign up for email updates as we complete planning. Read on for background and details.
Background
The Discovery Corridor Wastewater Transmission System (DCWTS), which provides service to the City of Ridgefield and the Discovery Corridor, is a multi-phased regional conveyance system that directs wastewater southward to the Salmon Creek Treatment Plant. The existing City of Ridgefield sewer treatment plant is approaching capacity, and local comprehensive plans call for significant industrial and commercial development in and around Ridgefield. These large employment centers generate significant utility demand and the Salmon Creek Treatment Plant offers reliable low-cost wastewater treatment capacity to meet those needs.
Initial construction (Phase 1) was completed in 2017, and an upgrade to the 20th Avenue Trunk Sewer was completed in 2023. Recent planning work identified upgrades to three components of DCWTS to accommodate growth in the service area: Pioneer Canyon, Neil Kimsey Regional (previously known as 209th Street), and Legacy pump stations. To provide efficient delivery, this work has been split into two packages called DCWTS Phase 2A and 2B. Phase 2A includes work on the three pump stations, and Phase 2B adds an additional force main to serve the Legacy Pump Station.
Phase 2A
The DCWTS Phase 2A project will upgrade the capacity of the Pioneer Canyon and Neil Kimsey Regional pump station and force main systems. The project will also address current facility deficiencies at Pioneer Canyon, Neil Kimsey Regional, and Legacy and enhance monitoring of the facilities. Additional project details are available in the project profile.
Schedule
Design is complete and the project is currently in the bid and award phase.
Procurement of electrical and mechanical equipment is required. Some of these items have long lead times that will impact the start of on-site construction activities and overall duration of the construction phase of the project.
Construction Impacts
Pump station improvements are expected to be contained within existing pump station sites. Staging of equipment may require limited traffic control.
Sewer service will be maintained during construction.
Funding
Funding for the project will come from a low-interest Public Works Board Loan to be repaid by system development charge revenue, which is collected from new development.
Phase 2B
The DCWTS Phase 2B project will upgrade the capacity of the Legacy pump station and force main system by installing a 20-inch diameter force main. A comprehensive evaluation of force main route alternatives concluded the preferred route is to follow the existing 16-inch Legacy force main. This route will head south from the existing pump station down NE 20th Avenue, across I-205, and south to NE 129th Street. Additional project details are available in the project profile.
If you would like to receive updates on the project please sign up for project updates at the bottom of this website.
Schedule
The project is in the early stages of design. Construction is currently planned for 2026.
Construction Impacts
Construction methods to install the sewer are being developed but will generally use open-cut excavation methods, which consists of digging a trench, laying pipe, and backfilling. Careful planning is taking place to minimize impacts to local businesses and the traveling public. Close coordination with Clark County and Washington State Department of Transportation is ongoing.
Sewer service will be maintained during construction.
What to expect during construction:
- Construction of the sewer pipeline will impact businesses, residents, and the travelling public along NE 20th Avenue and intersections at NE 134th Street and NE 129th
- The District is committed to maintaining regular and consistent communication with affected businesses and residents to minimize and mitigate the impacts of construction.
- More information will be provided regarding anticipated construction impacts as design progresses.
Funding
Funding for the project will come from a low-interest Public Works Board Loan to be repaid by system development charge revenue, which is collected from new development.
Project Sign-Up
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