The Patterson Pass Water Treatment Plant has been serving the Tri-Valley since 1962, treating imported surface water from the adjacent South Bay Aqueduct using dual-media filtration and chlorine treatment techniques. The plant is currently being upgraded to add ozone treatment. The plant capacity will also be expanded from 12 million gallons per day (mgd) to 24 mgd.
The Del Valle Water Treatment Plant has been serving the Tri-Valley community since the 1970s and was recently upgraded to add raw water ozonation to the existing treatment process. The ozonation project is the latest investment by Zone 7 to support the continued delivery of high-quality water to Zone 7 customers.