Water’s odyssey from sewer to cup
The water utility in Orange County, Calif., has been drawing attention since it opened the world’s largest water recycling facility of its kind in January.
Fountain Valley, Calif.
Tap water has never had so many fans. From neighboring states to distant countries, admirers have been traveling here to see – and drink – what’s coming from the faucets in thousands of southern California homes.Skip to next paragraph
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Orange County’s water utility has been drawing the gaze of engineers, scientists, and policymakers since it opened the world’s largest water recycling facility of its kind in January to scrub clean treated wastewater and turn it into drinking water.
Now, many of those admirers want to replicate Orange County’s model of replenishing freshwater supplies using purified sewer water. Los Angeles, San Jose, south Florida, and other locales are pursuing similar projects, which experts say are essential for coping with water scarcity likely to be associated with global warming.
“For much of the world, water reuse is going to become a fact of life. The Orange County project is a model for the world,” says William Cooper, director of the Urban Water Research Center at the University of California, Irvine. “When you have a precious resource like water, you have to do everything you can to protect it.”
The county’s $480 million Groundwater Replenishment System takes already-treated wastewater from the sanitation district next door and sends it through a rigorous three-step cleaning process. It’s washed through microfiltration, pressed through rows of reverse osmosis membranes, and then blasted with ultraviolet light and hydrogen peroxide. After 45 minutes, out comes clean, drinkable water.
The final product doesn’t go directly to the tap. Instead, half of it flows into a seawater barrier and the other half into a freshwater pond that replenishes the county’s groundwater basin. In the end, the recycled water makes up about 20 percent of the drinking water for roughly 2.3 million people.
It’s not necessarily the technology that has garnered Orange County such attention from water utilities around the globe. Recycling wastewater has been going on to lesser degrees elsewhere for some time. What has intrigued many is that the system met almost no public resistance when it came online in January.
“Technologically, it’s almost trivial for us to do this now. The key is to get public acceptance and political buy-in,” says Dr. Cooper, an early pioneer in water reuse practices.
And that was something Orange County worked hard to do from the beginning, spending $4 million in public outreach over 10 years. Water utility officials in Orange County had seen a similar plan squashed in San Diego when the recycling issue became politicized and the public turned away from the idea of turning toilet water into tap water.