48-inch Force Main: Unit 4
Client
Silicon Valley Clean Water (SVCW)
Location
Redwood City, CA
Unit 4 is the connection phase of this multi-unit 48-inch Force Main project. The new HDPE pipeline was connected to the existing system at two points along the alignment. The initial design called for connection at the two intermediate pump stations; Redwood City and San Carlos. Due to a change in the overall force main system between San Carlos and the treatment facility, the San Carlos connection was changed to a location on Inner Bair Island part of the USF&W habitat.
This project included the installation of four (4) 48-in double disc knife gate valves, temporary bypass piping and significant coordination with the SVCW Operations and Maintenance staff. This project was identified as severely difficult in nature and thus the owner wanted to be closely involved in the process. As a member of the overall project design team, we suggested the use of a different project delivery method known as the Design-Assist method.
In this method the owner and designer provide an approximate 30% design. This information is then let out through a Request for Proposal (RFP) process requesting contractors to provide a price to assist with the final design and then construction of the project. This process provided significant benefits as the contractor was involved early and provided their unique perspective on how best to construct the project. Several innovations were realized so that the overall impact to the operation of the pump stations, existing force main and treatment facilities were significantly limited.
