Central Trunk Sanitary Sewer Rehabilitation
Sacramento Area Sewer District (SASD), California
West Yost provided preliminary and final design of one of the largest cured-in-place-pipe (CIPP) projects in the US, 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 is also included in the project. The portion of the Franklin Trunk to be rehabilitated is 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, and West Yost worked with SASD staff in communicating with the public, addressing noise issues, and evaluating trucking limits to reduce public impacts.
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 has
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
The award-winning Central Trunk Sewer Rehabilitation Project, to rehabilitate approximately 44,700 feet of sewer, is the largest CIPP project in the country.
- California Water Environment Association, State Level, 2010 Engineering Achievement Award
- American Society of Civil Engineers, Sacramento Section, 2010 Outstanding Environmental Project
- American Public Works Association, Sacramento Chapter, 2010 Project of Year Award
- California Water Environment Association, Sacramento Area
Section, 2010 Engineering Achievement Award