College Oak Drive Pump Station
Sacramento Area Sanitation District

West Yost designed a new gravity sewer and 2 mgd lift station to replace an existing 12/10/8-inch siphon pipeline that was performing poorly and was difficult to maintain. Services completed by West Yost included surveying, permitting, design, and right-of-way services. The project included distribution of 480-volt power, and instrumentation controls and communication via radio with SCADA.

The sewer crossed under the environmentally-sensitive Arcade Creek, adjacent to American River College. West Yost evaluated replacing the existing siphon with a new double-barrel siphon. However, as with the existing system, the lack of fall or hydraulic head would have still required that the upstream system surcharge push the flow through the siphon. West Yost proposed replacing the siphon facility with a new gravity sewer under Arcade Creek and a 2 mgd submersible lift station and this alternative was selected because it was easier to maintain and provided a higher level of protection to Arcade Creek against sewage spills.

The 12-inch diameter gravity sewer was installed under Arcade Creek by the horizontal directional drilling (HDD) trenchless construction method. By using HDD, the project minimized impacts to the environmentally sensitive Arcade Creek.