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Central Trunk Sanitary Sewer Rehabilitation

Sacramento Area Sewer District (SASD), California

Central Trunk Sanitary Sewer Rehabilitation

West Yost provided preliminary and final design for one of the largest cured-in-place-pipe (CIPP) projects in the U.S., to rehabilitate approximately 44,700 feet of sewer using an innovative liner material (iPlus®). The trunk line is 42-inches to 60-inches in diameter and runs under major streets, residential backyards, creeks, a freeway, through protected wetlands, and near many homes, schools, and businesses. Approximately 3,000 feet of the Franklin Trunk was also included in the project. The rehabilitated portion of the Franklin Trunk was 33-inch diameter sewer reinforced concrete pipe

This award-winning project involved successfully addressing significant engineering and construction challenges. Significant engineering challenges included full sewer continuous operations during construction, complicated bypass planning and implementation, and a sizable crossing under Highway 99, where two trenchless technology alternatives were evaluated including bore and jack, and horizontal directional drilling. Community relations were also a significant issue on this project. West Yost worked with SASD staff in communicating with the public, addressing noise issues, and evaluating trucking limits to reduce public impacts. 

Central Trunk Sanitary Sewer Rehabilitation

SASD’s Central Trunk sanitary sewer serves the southeastern portion of Sacramento, conveying wastewater to the Sacramento Regional Wastewater Treatment Plant (SRWTP). The eight-mile Central Trunk sewer was constructed in 1961 of unlined reinforced concrete pipe. After nearly 50 years of service, the sewer was severely corroded. Restoring the structural stability of the Central Trunk with minimal decrease in capacity was the project’s primary goal. SASD aimed to meet this goal in a cost-effective manner with as little disruption to the community as possible, and therefore chose CIPP as the single method of rehabilitation.

Sanitary Sewer Rehabilitation (SASD)

The award-winning Central Trunk Sewer Rehabilitation Project, to rehabilitate approximately 44,700 feet of sewer, is the largest cured-in-place-pipe (CIPP) project in the country.