When a toilet is flushed in California, the water can end up in a variety of places, including ice in a skating rink, artificial snow on ski slopes, and pipes that provide irrigation for farmland. And, very soon, in your drinking glass. On Tuesday, California regulators will vote on new rules that will allow water agencies to recycle wastewater and reuse it in the pipes that deliver drinking water to homes, schools, and businesses.
It’s a significant step forward for a state that has struggled for decades to provide a reliable source of drinking water to its 39 million residents. And it represents a shift in public opinion on a subject that, just two decades ago, sparked a backlash that scuttled similar projects.
Since then, California has experienced multiple severe droughts, the most recent of which was the driest three-year period on record, leaving the state’s reservoirs dangerously low.
“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 set to allow direct use of recycled wastewater in drinking water
For decades, California has used recycled wastewater. It has been used to make ice for the Ontario Reign minor league hockey team’s rink in Southern California. It has been used to make snow at Soda Springs Ski Resort near Lake Tahoe. Farmers in the Central Valley, which produces the majority of the country’s vegetables, fruits, and nuts, use it to water their crops.
However, it has not been directly used for drinking water. Orange County operates a large water purification system that recycles wastewater before reusing it to recharge underground aquifers. The water mingles with the groundwater for months before being pumped up and used for drinking water again.
The new California rules would allow – but not require – water agencies to take wastewater, treat it, and then reintroduce it into the drinking water system. California would be only the second state, after Colorado, to allow this.
The rules would require that all pathogens and viruses be removed from the wastewater, even if they are not present. That differs from regular water treatment rules, which only require treatment for known pathogens, according to Darrin Polhemus, deputy director of the California Water Resources Control Board’s division of drinking water.
In fact, the treatment is so strict that it removes all of the minerals that make fresh drinking water taste good, which means they must be added back at the end of the process.
“It’s at the same drinking water quality, and probably better in many instances,” Polhemus said.
California to vote on letting wastewater into drinking water supply
Because building these treatment facilities is costly and time-consuming, Polhemus believes it will initially be limited to larger, well-funded cities. San Diego, for example, has a plan to build a water recycling program that they claim will account for nearly half of the city’s water by 2035.
Water agencies will require public assistance to complete these projects. The rules require water utilities to inform customers about recycled water before they begin using it.
In San Jose, local officials have opened the Silicon Valley Advanced Water Purification Center for public tours “so that people can see that this is a very high tech process that ensures the water is super clean,” said Kirsten Struve, assistant officer for the water supply division at the Santa Clara Valley Water District.
Currently, the agency uses the water to irrigate parks and playing fields. However, they intend to use it for drinking water in the future.
“We live in California where the drought happens all the time. And with climate change, it will only get worse,” Struve said. “And this is a drought resistant supply that we will need in the future to meet the demands of our communities.”
