Seaside Force Main

The Seaside Transfer Station (STS), a 3.4-mile-long, 20-inch ductile iron sewage pipeline, provides critical sewage infrastructure for the City of Ventura by pumping wastewater to their treatment plant. Originally installed in the 1970s, the STS is located on the beach at Surfer’s Point next to the iconic Ventura County Fairgrounds. Running under the City’s beachfront promenade along hotels and residences, the STS force main conveys about 30% of the total sewage generated within City limits and is a high priority project to protect both the local community and marine environment.

The force main was producing toxic hydrogen sulfide due to long detention times of the sewage during low flow periods. Originally, two parallel pipelines were designed as back-up in the event of system failure, but the last 6,000 feet of the secondary line was never completed. After nearly 50 years of using the primary line, the City decided it was time complete an effective back-up plan to avoid main breaks and sewage spills.

The City selected Cannon to complete the design for the second parallel force main to make the dual force main system operational. Cannon conducted a hydraulic analysis of the STS lift station and force mains and produced a condition assessment and rehabilitation study. These efforts included trenchless replacement options, pipe material selections, design alternatives, odor control options, and estimated construction costs. We studied the force main alignment, prepared a condition assessment study for the STS lift station facility, and developed plans and specifications for a new gravity sewer main and CIPP lining of the existing force mains.

The Seaside Force Main Project reduced system strain by converting approximately 6,000 feet of force main to gravity sewer. This reduced turbulence into the existing gravity sewer, lowered energy and maintenance costs, and reduced hydrogen sulfide production.