Selection and Implementation of Nonpotable Water Recycling in “Silicon Valley” (San Jose Area) California

Abstract

South Bay Water Recycling, a nonpotable water recycling project in the San Jose, California (USA) area, was commissioned in 1998 to supply up to 60,000 m3/day (15 mgd) of high-quality treated effluent to nearly 200 customers for irrigation and industrial use. The project was selected, along with water conservation, as the most effective approach to protecting salt marsh habitat at the south end of San Francisco Bay from degradation due to low-salinity discharge from the San Jose/Santa Clara Water Pollution Control Plant. The project was selected over an outfall discharge based in part on its ability to offset demand for potable water by municipal and industrial customers, including computer-related industries in northern California's “Silicon Valley”. Project development began in 1991 with feasibility and conceptual design studies. Preliminary project design and surveying began in 1994, and construction commenced in 1996. The project was completed in July 1998 at a cost of approximately $140 million (US), and consists of a 90 km (60 mile) pipeline with three pump stations and one reservoir. In addition to transmission and distribution facilities, construction included customer retrofits to segregate the nonpotable system from each site's potable supply.