Salmon Creek Treatment Plant Columbia River Outfall
Project Details
Owner: Clark Regional Wastewater District (Discovery Clean Water Alliance)
Location: Vancouver, WA | April 2021 – July 2022
Advanced American Construction (AAC) was contracted by Clark Regional Wastewater District to replace the aging outfall pipeline for the Salmon Creek Treatment Plant, which serves over 120,000 residents in Clark County, WA. The project involved installing 1,200 linear feet of new 48” effluent pipeline, including 700 feet in the Columbia River to support future population growth and increased treatment capacity. A new partially buried diffuser was also added to improve water quality through enhanced mixing.
Construction was performed within a narrow in-water work window and under challenging conditions in one of the nation’s busiest commercial waterways. Crews operated alongside heavy shipping traffic in the Columbia River, in currents up to 70 feet deep, with limited shoreline access and tidal fluctuations. AAC deployed a crane barge for river trenching and worked closely with subcontractor Tapani to extend access from shore, float and sink the HDPE pipe, and install steel diffuser sections.
Environmental protection was key to project success. Over 900 feet of turbidity curtain were installed and repeatedly maintained to prevent sediment disturbance from impacting surrounding ecosystems. Despite significant material delays, site theft, COVID protocols, and severe weather, AAC completed the installation safely, on time, and without service disruption.
Project Highlights
- 1,200 LF of 48” effluent pipe, 700 LF in Columbia River
- Work completed within federally regulated in-water window
- Dual crane + long-reach excavation in deep, fast-moving water
- Over 900 LF of turbidity curtain installed and maintained
- Satisfactory completion despite material delivery delays of 6+ months
- No disruption to plant operations
- Completed safely and on schedule
Project Awards
