San Jose Water has announced plans to test a new system that could turn recycled wastewater into drinking water, part of a broader effort to strengthen Silicon Valley’s long-term water supply as drought and climate pressures grow across the western United States.
The private utility will launch a proof-of-concept demonstration of direct potable reuse, or DPR, an advanced treatment process that purifies recycled wastewater to meet California’s recently adopted regulations for drinking water use, according to SJW officials on Wednesday.
“Our goal is to test this new technology to see if it can become a reliable and affordable long-term water source for our customers,” SJW President Tanya Moniz-Witten said in a statement.
The demonstration will rely on a mobile purification unit costing about $3 million. Since the system can be moved around the utility’s service area, utility officials said SJW will allow testing in multiple locations while also helping educate the public about the technology.
The company expects the pilot system to be available within about two years, including time needed for testing and evaluation under state regulatory requirements.
SJW officials said they are working with regional partners, including the San Francisco Public Utilities Commission and South Bay Water Recycling, to share technical knowledge and help develop future treatment options across the region.
Results from the demonstration and community feedback will help guide whether the utility moves forward with a full-scale recycled-water purification plant.
Water agencies across the western United States are increasingly exploring direct potable reuse as a drought-resilient local supply. Colorado adopted the nation’s first statewide DPR regulations in 2023, followed by California in 2024 and Arizona in 2025.
San Jose Water said regional cooperation will be key as utilities evaluate future water sources that can support population growth while keeping customer costs manageable.
“Every infrastructure decision ultimately affects the bills customers pay,” Moniz-Witten said. “That’s why it’s critical that new water projects are designed efficiently and managed responsibly from the start.”