When you turn on your tap in California, the water could come from a variety of sources: lakes, rivers, reservoirs, and soon, thanks to a new rule approved by state regulators, wastewater from toilets and showers.

California’s Water Resources Control Board voted Tuesday to allow water agencies to recycle wastewater into clean drinking water to be sent straight to people’s taps.

Zoom out: With its new program, called Direct Potable Reuse, California is the second state after Colorado to allow wastewater to be recycled into drinking water, The Associated Press reported.

The state already uses treated wastewater for a variety of uses, including watering crops, but it hasn’t been used for drinking water until now.

Why it matters: The use of highly treated recycled wastewater will provide a reliable source of safe drinking water to the state’s over 39 million residents during worsening droughts, proponents of the new program say.

Board Chair Joaquin Esquivel told CNN that the move will reduce California’s dependency on water supplies shrinking due to climate change, such as the Colorado River.

Quotes to note: “Water is so precious in California. It is important that we use it more than once,” Jennifer West, managing director of WateReuse California, told The Associated Press.

Darrin Polhemus, deputy director of the State Water Board’s Division of Drinking Water, says the treatment process for wastewater is so thorough that the drinking water will be some of the most pure drinking water available.

“This will be by far the most well-treated, highest-quality water served to the public,” Polhemus said, according to the Los Angeles Times. “It’s an incredible amount of treatment.”