The San Diego City Council met on Tuesday, Nov. 18 and unanimously approved the Pure Water San Diego program — a 20-year water recycling project expected to purify up to 15 million additional gallons of drinkable water daily by 2023.
Under the new program, wastewater would first be sent to an Advanced Water Purification Facility, where it will undergo several purification processes like membrane filtration and advanced oxidation. Afterward, wastewater will be blended with imported water in an environmental buffer — the San Vicente Reservoir, in this case — before finally being sent to a regular drinking water plant for distribution. The reclaimed water would be monitored at all stages of purification.
Eventually, the Pure Water program would bypass the natural reservoir, sending water straight to the final treatment plant for direct potable reuse. San Diego is currently using funds from Proposition 50 and Proposition 84 to research additional protective barriers for this DPR method.
Although the short-term goal is to provide 15 million gallons per day by 2023, the city’s long-term hope is that more advanced facilities will increase output to 83 million gallons of purified water by 2035, accounting for over one-third of the city’s total supply. The program may eliminate the need for expensive upgrades to the existing Point Loma Wastewater Treatment Plant, which currently cleans sewage that is pumped into the Pacific Ocean. Pure Water San Diego is funded by a variety of grants with an estimated total price tag of $3.5 billion. The city is currently providing free tours of the advanced treatment plant.
According to the City of San Diego Public Utilities Department currently imports up to 85 percent of its water. With recurring droughts and depleted reserves, the city had been working with other organizations to find ways to maximize water usage since 2004. In January 2004, City Council authorized a water-reuse study to comprehensively research all opportunities for recycling water, and a second study was conducted in 2009. The compiled data culminated into the Pure Water San Diego program.
A demonstration project at Miramar was also implemented in 2007 to test its feasibility. Operating a study-scale facility, the city found that the process efficiently provided water that met or exceeded all federal and state -safety standards. Since 2008, Orange County has already been using a similar purification process as well.
San Diego Mayor Kevin Faulconer and many other environmental groups endorsed Pure Water San Diego as a much-needed effort to reduce water waste and the city’s dependence on outside regions for clean water. They made efforts to dispel the negative, “toilet-to-tap” image commonly associated with such technology.
“For our community to continue to prosper, it will take truly integrated water management and infrastructure approaches,” San Diego Coastkeeper waterkeeper Matt O’Malley said in a Nov. 13 press release. “The Pure Water program is exactly this type of approach, dealing with ocean -water quality improvement while also providing a locally controlled drinking -water supply.”