Chain of Lakes Well House with blue sky and clouds


Investing in a strong and sustainable system

Zone 7 keeps water flowing to the Tri-Valley through an extensive distribution network that relies on both long-term capital investment projects and routine maintenance, upkeep, and prevention to keep it running smoothly. To deliver high-quality water, we have made major investments in ozone treatment at both of our surface water treatment plants a priority for the Zone 7 Capital Improvement Program because ozone is the best alternative to chlorine.

We completed the Del Valle Water Treatment Plant (DVWTP) Ozonation Project in the fall of 2020, and the ozone system has been operational for the majority of the 2020-2021 fiscal year. 

Zone 7 continued construction of ozonation treatment facilities to improve quality, taste and odor at the aging Patterson Pass Water Treatment Plant (PPWTP) this year. The project will also increase and stabilize the treatment plant’s production capacity from 12 to 24 million gallons per day, as well as add clearwell storage, new filters, renewal, replacement and rehabilitation of aging components of the plant. Decades in the planning, this project highlights the agency’s efforts in long-term planning, fiscal responsibility, and commitment to water quality and public health. The new facilities are expected to be complete and operational in 2022.

Significant Capital Improvement Projects

Each year, Zone 7 invests in a variety of capital improvement projects to keep our water treatment and delivery systems running optimally. Here are some of the key projects completed this year that will keep our infrastructure operating smoothly for years to come.

DVWTP Roadway/Parking Lot and Post-Ozonation Project

repairing chemical delivery access roads

Currently in construction, this project will repair the parking lot and repair the access road for more efficient chemical deliveries. This project is needed to improve operational flexibility and reliability of the treatment plant and also includes modifications needed for filter backwash pumps, improvements to protect against system overflows, chemical tank repair, and a new polymer system.

Mocho Groundwater Demineralization Plant Concentrate Conditioning System

reduce the frequency of costly upkeep procedures

This project provides a sulfuric acid storage and feed system to help condition the demineralized concentrate removed from the groundwater. This helps to minimize scaling inside the discharge pipeline and reduce the frequency of costly scale removal and cleaning activities. The project is currently in design and construction is expected to begin in time for the system to be complete and operational in 2023

North Canyons HVAC System Replacement Project

sustaining Zone 7’s communications network, business operations, and public meetings

This project is to replace the outdated, inefficient, and high maintenance HVAC system at Zone 7’s North Canyons office. This office is integral for Zone 7 business operations and public meetings. The office is also one of the facilities that serves as part of Zone 7’s communications network. The project is currently in construction and is expected to be complete and operational by the spring of 2022.

Chain of Lakes PFAS Treatment Project

preparing to keep your water safe for generations to come

Currently in planning and design, this project is to construct a PFAS treatment facility at Zone 7’s Chain of Lakes Well No. 1 site so that all of the Chain of Lakes wells can meet regulatory requirements for operation. The treatment is to remove PFAS primarily through media adsorption so that groundwater from the Chain of Lakes wells is safely below the future PFAS maximum contaminant levels being established by the State of California.

Valley Pump Station Project

This project is being accelerated as a drought emergency project to be completed by the fall of 2022. The pump station is to increase Zone 7 water system reliability during times of drought and emergencies. When groundwater from the production wells located in the western area of the water system is needed in the eastern area, water can be pumped more easily while taking stress off the production well facilities.

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Financial Update