Water Purification

For more than two decades, water agencies in San Diego County have promoted water reuse as part of the region’s multi-faceted water supply diversification strategy. Today, about 80 percent of the region’s water supplies are transported hundreds of miles from the Colorado River and the State Water Project, which originates in Northern California.

In coming years, potable reuse projects are expected to help water agencies optimize existing infrastructure, increase locally controlled water supplies, and provide environmental benefits while continuing to protect public health. The Water Authority is working with its member agencies through the Potable Reuse Coordination Committee to support development of potable reuse projects in the San Diego region and develop a regulatory framework for direct potable reuse.

By supporting rigorous scientific analysis, securing money for studies, and sponsoring state legislation to speed the adoption of regulations, the Water Authority and its member agencies have become leading advocates for the next generation of locally controlled, drought-resilient drinking water supplies.

What is potable reuse?​
Potable reuse is the process of purifying wastewater so it can be reused in the drinking water system. ​

Is planned potable reuse safe?

Yes. The water purification process employs advanced multi-barrier treatment technology. This separates pollutants from the water, purifying it to a level that fully complies with both federal and state drinking water standards. Like other drinking water supplies, it is rigorously tested and publicly reported.​

Is anyone drinking recycled wastewater already?
Yes. Reuse occurs when wastewater has been discharged to rivers or lakes, then withdrawn, treated and distributed downstream. For instance, there are more than 300 wastewater outfalls on the Colorado River, a major source of drinking water for Southern California. In this situation, public health is protected through treatment required by the Clean Water Act and Safe Drinking Water Act.

Planned potable reuse started in California in 1962 through groundwater recharge in Los Angeles County. The largest planned potable reuse project is in Orange County, where the water agency has been injecting purified wastewater into an aquifer for decades, then reusing it to serve millions of people each year. Anyone who’s visited Disneyland has drunk potable reuse water.

What are the different uses of recycled water?
Potable reuse refers to purifying wastewater to be drinkable, while non-potable recycling refers to cleaning wastewater to a level acceptable for industrial and irrigation use. The decision on how best to recycle water depends on local infrastructure and the water demands of each agency.

How much water will potable reuse projects generate in San Diego County?​

By 2035, potable reuse projects are expected to produce approximately 110,000 acre-feet of water, enough to serve more than 220,000 typical homes. That’s enough water to meet about 16 percent of the forecasted demand in the San Diego region.​

Are there environmental benefits to potable reuse?​
Potable reuse replaces water that would otherwise have been removed from lakes, rivers or aquifers, then transported — sometimes hundreds of miles – to local homes and businesses. Potable reuse reduces stress on our waterways, and it can reduce wastewater discharges to the ocean.