Penitencia Water Treatment Plant

Service area
This plant typically serves an area from Milpitas in the north to Aborn Road in the south, supplying safe drinking water to 270,000 residential and commercial users.

Water source
The South Bay Aqueduct, owned by the California Department of Water Resources, provides most of the water to the Penitencia plant. Water from the Sacramento-San Joaquin Delta is pumped into the California Aqueduct and then into the South Bay Aqueduct (SBA) in Tracy. The SBA pipeline runs through the Livermore Valley and terminates at the Penitencia plant.

Capacity: Penitencia can treat and deliver up to 40 million gallons of water per day.

Date first operated: 1974

Plant Improvements 
The Penitencia Water Treatment Plant is the latest plant to integrate the use of ozone gas in its water treatment process to improve the district’s drinking water quality.  Ozone is an excellent addition to the drinking water treatment process because it is a very strong disinfectant. The use of ozone reduces the formation of chlorination byproducts.  Disinfection byproducts at high levels can be a health concern.  Ozone upgrades to the plant were completed in 2006. Landscape improvements, screens, facade panels and a new entrance were added in 2008.

Contact information
If you have any questions or concerns about the Penitencia Water Treatment Plant, please contact Neighborhood Liaison Jose Villarreal at (408) 630-2879, or by e-mail at [email protected].

Water Infrastructure Bus Tour

Valley Water is now offering free half-day bus tours to some of our water infrastructure facilities, which includes the Penitencia Water Treatment Plant. To learn more about this tour and upcoming dates, please visit our public tours webpage.