Design-build delivery opportunities for pipeline projects are increasing dramatically in the water and wastewater sector. As an informative example of successful delivery of a design-build pipeline, we will discuss the city of Modesto (City) North Valley Regional Recycled Water Program (NVRRWP) Pipeline in Modesto, California. The pipeline will convey highly-treated wastewater from the City's tertiary treatment plant and serve as an important regional solution to address water supply shortages faced by agricultural customers. This case study will explore various keys to successful delivery of the 7 mi (11.2 km), 42-in (1.06 m) diameter recycled water pipeline that included a 2,800 ft (853 m) long horizontal directionally drilled (HDD) trenchless crossing of the San Joaquin River in an environmentally sensitive area with seismically sensitive soils, including: 1) development of a successful design-build proposal: we will share strategies on how to structure an effective design-build team and prepare a winning proposal; 2) delivery strategies to fast-track schedule including early procurement and contract packages; 3) addressing open cut and trenchless design and construction issues that included balancing pipe/embedment design optimization in poor soils areas, geotechnical/seismic challenges through the San Joaquin floodplain, and schedule delays due to high San Joaquin River levels; 4) satisfying challenging environmental and regulatory agency permit conditions for the HDD crossing of the San Joaquin River using a collaborative approach between owner, contractor, designer, and agencies.
