Capital Project Updates


Zone 7’s Capital Improvement Program (CIP) is strategically planned to support the Agency’s long-term water quality, reliability and flood protection goals. The plan includes asset management, infrastructure investment and major construction projects.

Find updates on our major capital projects in this section and follow along as we report on major milestones in these important investments in our community’s future.


Stoneridge Well PFAS Treatment System Project

In a continuing effort to supply the Tri-Valley with safe, reliable water that surpasses state and federal drinking water standards, Zone 7 is in the final stages of constructing a water treatment system to address Per- and Polyfluoroalkyl substances (PFAS) found in the local groundwater at the Stoneridge Well. The treatment system went online in September 2023 and final construction at the facility is anticipated to be complete by Spring 2024.


Del Valle Water Treatment Plant

Del Valle Water Treatment Plant amidst grassy hills.

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.


Patterson Pass Water Treatment Plant

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 has recently been upgraded to add ozone treatment.  The plant capacity has also been expanded from 12 million gallons per day (mgd) to 24 mgd.