California OKs Drinking Recycled Wastewater

Wastewater to be treated for all pathogens and viruses before reaching tap
By Newser Editors and Wire Services
Posted Dec 20, 2023 5:33 AM CST
California OKs Drinking Recycled Wastewater
The Silicon Valley Advance Water Purification Center is pictured Wednesday, Dec. 13, 2023, in San Jose, Calif. Treated wastewater is purified into drinking water at the facility.   (AP Photo/Terry Chea)

When a toilet is flushed in California, the water can end up in a lot of places: An ice skating rink near Disneyland, ski slopes around Lake Tahoe, farmland in the Central Valley. And—coming soon—kitchen faucets. California regulators on Tuesday approved new rules to let water agencies recycle wastewater and put it right back into the pipes that carry drinking water to homes, schools, and businesses, the AP reports. It's a big step for a state that has struggled for decades to secure reliable sources of drinking water for its more than 39 million residents. And it signals a shift in public opinion on a subject that as recently as two decades ago prompted backlash that scuttled similar projects.

Since then, California has been through multiple extreme droughts, including the most recent one that scientists say was the driest three-year period on record and left the state's reservoirs at dangerously low levels. "Water is so precious in California. It is important that we use it more than once," said Jennifer West, managing director of WateReuse California, a group advocating for recycled water. California has been using recycled wastewater for decades. But it hasn't been used directly for drinking water. Orange County operates a large water purification system that recycles wastewater and then uses it to refill underground aquifers. The water mingles with the groundwater for months before being pumped up and used for drinking water again.

California's new rules would allow—but not require—water agencies to take wastewater, treat it, and then put it right back into the drinking water system. California would be just the second state to allow this, following Colorado. It's taken regulators more than 10 years to develop these rules, a process that included multiple reviews by independent panels of scientists. A state law required the California Water Resources Control Board to approve these regulations by Dec. 31—a deadline met with just days to spare. The vote was heralded by some of the state's biggest water agencies, which all have plans to build huge water recycling plants in the coming years.

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The Metropolitan Water District of Southern California, which serves 19 million people, aims to produce up to 150 million gallons per day of both direct and indirect recycled water. A project in San Diego is aiming to account for nearly half of the city's water by 2035. Water agencies will need public support to complete these projects—which means convincing customers that not only is recycled water safe to drink, but it's not icky. California's new rules require the wastewater be treated for all pathogens and viruses, even if the pathogens and viruses aren't in the wastewater, rather than just known pathogens, said Darrin Polhemus, deputy director of the division of drinking water for the California Water Resources Control Board. "It's at the same drinking water quality, and probably better in many instances," Polhemus said. (More California stories.)

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