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The Del Valle Water Treatment Ozonation Project is now online and actively serving the Tri Valley community! The Ozonation Project is the latest investment by Zone 7 in providing high-quality water that meets the rigorous Zone 7 standard. The Del Valle Water Treatment Plant, which has been serving us well since it was built in the 1970s, was upgraded and expanded to add raw water ozonation to the plant’s existing treatment process. The Ozonation Project brings best-in-class technology for disinfection to our water treatment, and represents a capital investment of $49 million, funded by bonds. As part of our commitment to high-quality water, Zone 7 is investing in ozone treatment because it is the best alternative to chlorine. Take a behind-the-scenes look at the new facility in our grand opening video.


What is ozonation?

Ozonation is a proven, successful water treatment method that uses ozone gas to effectively disinfect water. Ozone will replace chlorine as the main disinfectant at Del Valle Water Treatment Plant, resulting in higher quality finished water provided to our customers. This investment in ozonation will improve our water by treating taste and odor impacts from algae growth, reducing chlorine-related byproducts, and killing even more pathogens than chlorine.


Ozone is more effective than chlorine at treating organic matter and destroying algal byproducts. Studies have shown that ozone will make the treatment process more efficient. By adding ozone treatment, we will be able to reduce the use of chlorine and other chemicals, and minimize byproducts from chlorine disinfection.  

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Learn more

Info Sheet: Download the Del Valle Information Sheet. 

Construction Schedule:  Construction began in spring of 2018 and completed in summer of 2020.

Project Cost: The project invested $49 million into the facility.

FAQ: The original project documents provide more detailed information about the project:

Contact Information:  For any questions about this project, please contact Project Manager Brandon Woods at or (925) 454-5078.

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