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Montevina Water Treatment Plant Shutdown - Water Source Change for Some Customers

SJW is fortunate to have three different sources of water: groundwater, imported water and local mountain supplies. This diversity of sources allows SJW to be resilient when faced with unexpected challenges.

On July 25, 2022, equipment failure resulted in an emergency shutdown of the Montevina Ultrafiltration Plant. The drinking water supplied by the plant was not compromised during this event. However, the plant will remain shut down until SJW can complete the required repairs.

With this operational change, approximately 1,400 customers will transition from chloraminated surface water from the Montevina Ultrafiltration Plant, to chlorinated groundwater.

Map showing shutdown area of Montevina WTP including Los Gatos and mountain communities

The blending of disinfectants that occurs during the transition can cause taste and odor changes including chemical, chlorinous, or metallic aromas and flavors. Additionally, after the transition is complete, customers may notice a continuing difference between surface water and groundwater.

Groundwater disinfected with free chlorine has an earthier smell. Chlorine is more readily detectable in taste and smell than chloramine. Groundwater has higher hardness, meaning you may notice white deposits, scale and spotting on dishware. We anticipate this change to last for the next several months.

Please know that both sources meet all drinking water standards and are safe to drink.


For more information, visit our Water FAQs page at or call us at (408) 279-7900.