Your WaterFlood and Stream ManagementWatershed and Environment

The Patterson Pass Water Treatment Plant Upgrades and Ozonation Project will improve treated water quality, replace aging equipment, increase treated water storage capacity, and increase plant production capacity from 19 million gallons of water a day to 24 million gallons a day (MGD). The project will add new ozonation facilities, replace the existing ultrafiltration (UF) membrane filters and existing three conventional filters with six new conventional filters, and add a new 5 million gallon (MG) treated water storage tank.

Current Status:  The project is currently in the bid phase.

Construction Schedule:  Construction is anticipated to begin in January 2019, and be completed in early 2022.

Project Cost:  The project is estimated to cost $95 million for planning, design, and contruction; and is funded by water rates, new connection fees, and bonds.

Contact Information:  If you have any questions or concerns about this project, please contact Mona Olmsted at (925) 454-5033, or by email at