Tri-Valley Water Reuse A Promising Approach for Future Needs

"California has always faced water management challenges and always will," according to a 2011 report called Floods, Droughts, and Lawsuits: A Brief History of California Water Policy issued by the nonpartisan Public Policy Institute of California. "The state's arid and semiarid climate, its ambitious and evolving economy, and its continually growing population have combined to make shortages and conflicting demands the norm."

Those who live in California know all too well about water shortages and conflicting demands. The state has faced many droughts over its history, most recently in 2014 and 2015. The 2014 drought kicked off two years of mandatory water conservation measures for Tri-Valley businesses and residents. It also motivated several Tri-Valley agencies and a private utility to work together toward policies and related actions to address the Tri-Valley's future water needs.

Reliable Water Supplies Are Needed

Ensuring an adequate and reliable water supply for the Tri-Valley's growing population and economy is key to to the area's future health. That is why a group of officials met nine times between September 2014 and March 2018 in a series of Water Policy Roundtables. Elected officials from the cities of Pleasanton, Dublin, Livermore, and San Ramon met with officials from the Zone 7 Water Agency, the local wholesale water supplier; Dublin San Ramon Services District; and the California Water Service Company, a privately owned utility, to discuss how to meet the area's long-term water needs.

As a result of these meetings, the group agreed to collaborate on researching the feasibility of "potable reuse," a particular method of advanced water purification. Potable reuse is the planned reuse of purified wastewater to supplement drinking water supplies. As the name suggests, potable reuse reuses existing resources rather than requiring new sources of water. With the appropriate facilities, the method can be implemented locally and used even during a drought.

In March 2018 the group completed the Joint Tri-Valley Potable Reuse Technical Feasibility Study, which found that purifying wastewater to drinking water standards for potable reuse is feasible, will improve drinking water quality, will improve water supply reliability, and may improve the overall quality of water in the groundwater basin.

According to the study, purifying wastewater to drinking water standards could provide an additional 5,500 to 10,000 acre-feet of water per year, or an additional 7% to 15% to the Tri-Valley water supply annually. Six project alternatives were identified for detailed evaluation. The cost of these six alternatives range from $103 million to $222 million, and add only nominally to an average residential water bill. The next step involves a two-year planning study to analyze the specifics of an actual proposal. If potable reuse is eventually approved as one method to make the Tri-Valley's water supply more reliable, residents can expect to see a facility constructed and operating in about ten years.

No Silver Bullet

Currently, and for the foreseeable future, the Tri-Valley will be heavily reliant on the State Water Project, which has sometimes struggled to meet the water needs of its constituents. That is one of the reasons why the area needs to identify new sources of water. Inaction is not an option for local water agencies, residents, and businesses that want to see the local economy continue to thrive. Local observers note that potable reuse is not a "silver bullet" for solving the Tri-Valley's water needs, but it would help create a more diverse and thus more reliable portfolio of water supplies.

"The recent drought has underscored the need for alternative water supplies - such as potable reuse - to enhance long-term water supply reliability for the Tri-Valley," says Valerie Pryor, General Manager of the Zone 7 Water Agency. "Potable reuse offers unique advantages as a drought-resistant and local resource, which make it worth exploring further. The Tri-Valley community and water agencies are working together in this effort, and it will continue to be a collaborative process to potentially develop this local water supply."

A variety of other efforts are underway to conserve and reuse water. The City of Pleasanton began a Recycled Water Project in August 2017 with the goal of replacing drinking water used for local landscaping needs with non-potable water. The city's efforts will ultimately save approximately 450,000,000 gallons of potable water annually.

Hacienda was involved in the first phase of the project, and maintains nearly 70% of its landscaping with recycled, nonpotable water. Hacienda has also reduced its water use through drought-resistant landscaping and water-delivery upgrades that insure the minimum amount of water needed is delivered at the appropriate times.

Area businesses and residents can also help conserve water. The Zone 7 Water Agency website called Water-Wise Gardening offers a host of resources. According to the website, the leading cause of wasted water is incorrectly set and poorly managed irrigation controllers. An online water calculator offers important advice on how to set a controller properly and how to manage it thereafter.

The website also includes links to several rebate programs that reward homeowners and businesses for replacing water-thirsty lawns with more drought-tolerant plantings or landscaping, lists of appropriate plants for the regions, and additional resources.

"Water is a precious resource - and we never have enough to waste," says Pryor. "Businesses and residents should continue to use water wisely, and continue to stay engaged in water supply issues."

For more information about Water-Wise Gardening, please visit . For more information about the Joint Tri-Valley Potable Reuse Technical Feasibility Study, please visit . For more information about Hacienda and its water-conservation efforts, please visit .

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