Project Overview

The Salmon Creek Wastewater Treatment Plant (SCTP) receives and treats roughly 8–10 million gallons of wastewater per day from approximately 120,000 Clark County homes and businesses. The Phase 5 Expansion program is a planned investment which builds on four previous expansions over the past 40 years. The Phase 5 Expansion projects will continue through 2024. The Phase 5 Expansion projects will ensure that the treatment plant can continue to meet the region’s long-term wastewater treatment needs and continue safeguarding public health, environmental quality and our community’s economic future. Once complete, the Phase 5 Expansion projects will allow for future decommissioning of Ridgefield’s aging wastewater treatment plant and outfall into Lake River (after other projects are also completed within the local collections systems).

Phase 5 Expansion projects include: Columbia River Outfall, Columbia River Effluent Pipeline, Secondary Treatment Process Improvements, and Odor Control and Existing Facilities Improvements (completed in Fall 2021).

Interactive Map

Use the interactive map below to learn more about each project and the potential impacts related to construction.

Construction relating to the Columbia River Outfall and Effluent Pipeline project and the Secondary Treatment Process Improvements projects will require increased truck traffic carrying materials, equipment and workers to the construction sites. This increased traffic will impact area neighborhoods. Expect increased truck traffic on the roads highlighted during the periods of construction. Any landscape disturbances made during construction will be fully restored and we will work to minimize disruptions to commercial and recreational interests.

Stay Up to Date

Throughout the Phase 5 Expansion, interested community members can follow progress by subscribing to our newsletter.

Contact Us

If you have any feedback or thoughts you want to share with us contact us using the information below.

Robin Krause, PE

For more information, contact:
Robin Krause, PE
Principal Engineer | Transmission & Treatment
Clark Regional Wastewater District

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