The San José–Santa Clara Regional Wastewater Facility (RWF) in Alviso, California, is marking 70 years of operation as it advances a $2.2 billion, 30-year capital improvement program to modernize aging infrastructure.

The facility, which opened Nov. 8, 1956, treats an average of 110 million gallons per day (MGD) of wastewater from approximately 1.5 million residents and more than 17,000 commercial and industrial customers across eight South Bay cities. Jointly owned by San José and Santa Clara, the facility produces treated wastewater that is 99% purified before discharge into the South San Francisco Bay.

Recent modernization milestones include the October 2026 opening of a digested sludge dewatering facility and a cogeneration facility launched in 2021 that uses biogas to generate approximately 75% of the plant’s electricity needs.

The anniversary celebration includes public tours, the first offered since 2017, and a new virtual tour highlighting treatment operations. The facility also recently received recognition from the National Association of Clean Water Agencies for five years of perfect compliance with federal and state environmental regulations.