Water reuse has been an important tool in improving water supply reliability in water-scarce Southern California. Recycled water is the result of treating wastewater to tertiary standards as proscribed in Title 22 of the California Water Code. Tertiary-treated recycled water is non-potable and can only be used for permitted non-potable uses, such as irrigation or industrial processes. Regionally, increasing recycled water use is a priority to reduce reliance on imported water, which is energy-intensive, subject to curtailment during droughts, and expensive. Although individual agencies have worked to increase recycled water in the Project Area, there has been a nearly 20-year history of joint water recycling efforts.
In the late 1990s, Olivenhain Municipal Water District, Carlsbad Municipal Water District, Leucadia Wastewater District, and San Elijo Joint Powers Authority worked together on the first regional recycled water project in northern San Diego County, known as the North County Recycled Water Project. This first effort, totaling approximately $133 million in expenditures, was awarded $20 million in U.S. Bureau of Reclamation Title XVI funding. The end result was 10,000 acre-feet—over three billion gallons—of recycled water that is currently being delivered to the region’s customers each year. Today, the 10-member NSDWRC Coalition has formed to further advance recycled water in northern San Diego County through the Regional Recycled Water Project. The new project will maximize recycled water use among the agencies, develop interconnections to more efficiently distribute recycled water, and construct new water reclamation facilities to increase the supply of recycled water available to each of these agencies’ respective customers.
Recycled water makes financial sense, as well as sense from an environmental and water supply perspective. A large portion of the potable water in San Diego County is imported water. In 2013, imported water costs approximately $1,200 per acre-foot, with costs projected to rise every year. In general, recycled water costs approximately 15% less than potable water, in large part due to the offset of imported water. For large water customers, such as certain industrial users, or large-scale irrigators (e.g., golf courses), converting to recycled water can be a substantial cost saver.
Interested in learning if recycled water is an option for you? Contact your local water supply agency by visiting our Contact page.
Potable reuse is a form of water reuse in which wastewater is recycled, undergoes advanced treatment and reenters the supply system through direct or indirect means Portable reuse is a drought-proof, local supply that can be used to improve water supply reliability. Potable reuse involves adding advanced treated recycled water that meets all drinking water standards into a groundwater basin or reservoir where it blends with water from other sources. This process is called indirect potable reuse (IPR). Advanced treated recycled water can also be added directly into an existing potable water system, upstream or downstream of a water treatment plant. This process is called direct portable reuse (DPR).
In California, there have been a number of successful potable reuse projects, including the Groundwater Replenishment System in Orange County, the Water Purification Demonstration Project in San Diego, the West Basin Water Recycling Project in Los Angeles County, and the Inland Empire Utilities Agency Recycled Water Program in Riverside County.
The regulatory environment in California is changing to recognize that potable reuse, when implemented safely, is a valuable tool for meeting water supply demands. The State of California is in the process of finalizing draft regulations for groundwater augmentation projects using purified water, which will be available by 2016 as mandated by Senate Bill 918 (2010). Other regulatory activities include determining feasibility of developing uniform water recycling criteria for direct potable reuse by end of 2016.
Because the characteristics of each project vary from site to site, regulatory agencies have stated that recommendations for potable reuse projects will be made on an individual case basis and will be based on all relevant aspects of each project, including the treatment provided, effluent quality and quantity, spreading area operations, soil characteristics, hydrogeology, residence time, and distance to withdrawal.
While each individual scenario may be different, the overriding goal remains the same: produce purified water that at all times is of a quality that fully protects public health.
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