Recently celebrating its 150th anniversary, San Jose Water Company is an investor-owned utility serving more than 1 million customers in the South Bay near Los Gatos, California. Montevina Water Treatment Plant is its largest surface water treatment facility with a capacity of 30 million gallons per day. The WTP’s ability to treat water from the local watershed provides more reliable drinking water for its customers, compared to more expensive imported water.

For 50 years, the plant struggled to treat high turbid water produced during typical Northern California winter storms when water is plentiful. Now, with state-of-the-art membrane treatment technology, the plant can regularly treat water up to 100 nephelometric turbidity units. Prior to the improvements, the plant could not treat water above 15 NTU. 

After an extensive membrane evaluation, including a proof of performance test and development of an interactive selection tool that factored in system reliability, robustness, flexibility, ease of meeting operating and maintenance requirements, and technical support services, SJWC selected a European ultrafiltration treatment technology — making Montevina the largest BASF/Inge installation in the United States and the first in California. The technology selection process saved $1 million, allowing the SJWC/HDR team to design and build a new administration building and stay within the California Public Utilities Commission-approved $62 million project budget. 

Other innovative solutions included a new plant exit to improve safety during construction and plant operations, repurposing existing concrete structures to reduce schedule and cost, utilizing screw press technology to reduce solids disposal traffic in the nearby residential neighborhood, and conducting partnering and technical workshops. The highly collaborative environment enabled the owner and design-builder to thrive and overcome unique challenges during design and construction.