Colorado to reuse water for drinking, creating new supply

Castle Rock, Colo. (AP) — When Eric Seufert brewed a test batch of beer in 2017 with water from recycled sewage, he wasn't too concerned about the outcome. The engineering firm that approached him about the test explained the process, and together they sipped samples of recycled water. Seufert quickly understood it wasn't too different from how water is normally handled.

"Every stream and river in this country has someone putting in their wastewater after they've treated it," he said.

After tapping the keg and having a taste, the owner of 105 West Brewing Co. in Castle Rock, Colorado proudly served it at his bar.

Brewing beer, cooking food, and refilling water bottles with recycled wastewater could soon become standard practice in a state that's synonymous with its pristine-tasting snowmelt and mountain springs.

Last week, Colorado's water quality agency gave unanimous preliminary approval to regulate direct potable reuse — the process of treating sewage and sending it directly to taps without first being dispersed in a larger water body. Pending a final vote in November, the state would become the first to adopt direct potable reuse regulations, according to WateReuse, national group advocating for the method.

"Having well-developed regulations ... helps ensure projects are safe and that project proponents know what will be required of them," said Laura Belanger, water resources engineer with the non-profit Western Resource Advocates.

As the state's population explodes and regional water supplies dwindle, recycling water for drinking is a significant opportunity for stretching a limited supply, said Kevin Reidy, conservation specialist for the Colorado Water Conservation Board. And he said it's a game changer in a place like Castle Rock, a city of 75,000 just south of Denver nestled under its prominent namesake butte, that relies primarily on pumping finite groundwater for drinking.

"I think it's an important tool for the long term because it gives water providers options to respond to future scarcity of water supplies, whether drought-driven or other reasons," said Mark Marlowe, director of Castle Rock Water.

The utility already reuses about 14% of its wastewater, sending it to a creek from the treatment plant, and re-drawing it farther downstream. But as climate change leads to more arid conditions in the western U.S., the creek's flow is becoming less reliable.