CONTENT EXPIRES: December 31, 2025

The Silicon Valley Clean Water Gravity Pipeline Tunnel Project is a 3.2 mile long, 11 ft. ID sewer pipeline project excavated by a 16 ft. diameter EPB TBM in Redwood City, California. A key technical challenge was low ground cover under shallow structures and roadways in a challenging geological formation that commonly generates surface settlements. The sensitive context of this project led the owner, SVCW, in 2017 to select a progressive design and build delivery method—a first for North America. As the project is now complete, the points of view of all parties involved in the project have been captured and reflected upon. This paper shares the perspectives from the Owner, Construction Manager, Engineer of Record, technical advisors and Contractor to discuss the merits of the PDB delivery method while retracing the evolution of the procurement, the design, the project approach, the value engineering exercises, the technical development alongside the risk assessments, the team building, and the construction from the beginning to final completion.