Water Quality

The Zone 7 Standard for Water Quality


Zone 7 provides high-quality treated drinking water to four water retailers serving over a quarter million residents and businesses. This water is delivered to the City of Livermore, City of Pleasanton, Dublin-San Ramon Services District and the California Water Service Company, along with some direct customers. Zone 7 water performs better than most state and federal health standards, as a direct result of our more stringent internal water quality targets.

Zone 7’s Water Quality Management Program was developed in collaboration with our retailers and other partners and establishes the standard for both treated and untreated water quality. This moves us beyond regulatory compliance to provide an additional margin of safety while addressing local concerns for taste, odor and water hardness.

Water Academy Rewards

Water Treatment Facilities


Photo of a large body of water with water treatment equipment along the surface

Zone 7 operates two surface water treatment plants (Del Valle Water Treatment Plant and Patterson Pass Water Treatment Plant), the Mocho Groundwater Demineralization Plant, 10 groundwater supply wells and a state-of-the-art water quality testing laboratory. Water treatment facilities are staffed by talented and committed experts in their fields who make a world of difference when it comes to bringing safe water to the Tri-Valley community.


Dive into the Wondrous World of Water

Three large white tanks holding liquid oxygen

The world of water quality is often filled with complex terms and scientific language – from parts per trillion to turbidity. Luckily the technicians at Zone 7’s state-of-the-art lab conduct the science to ensure customers have safe and clean water. In order to provide full transparency, the Wondrous World of Water campaign helps answer the question, “what in the world does all this mean?”


Annual Water Quality Reports

Test tubes and glass beakers filled with different colored liquids.

Step inside the world of water and learn how Zone 7 Water Agency ensures that drinking water is safe, clean and sustainable in these Water Quality Reports, also commonly referred to as the Consumer Confidence Reports.


Source Water Assessment Reports

Deep blue body of water with mountain ridge in the background.

Zone 7 Water Agency draws from a diverse portfolio of drinking water sources including local and imported surface water as well as groundwater which we pump from wells. We carefully monitor all these sources to ensure their continued quality and to protect the safety of our water supply.