On a hot day, there’s nothing quite like a refreshing drink of water. But how would you feel if that water was sourced from the sewer?

As cities across the West brace for a drier future, they’re investing in advanced water purification technology. It flushes out the contaminants in wastewater so that the murky stuff that goes down your toilet can eventually come out ready to drink at your sink.

“There’s a lot of uncertainty here in terms of water resources, so we think that this is that next bucket of water that we need to tap into,” said Nazario Prieto, assistant director of Phoenix Water Services.

The city of 1.6 million people is building its first advanced water purification plant that could eventually process up to 15 million gallons of wastewater a day.

Cities across the country have long treated wastewater and then pumped it into riverbeds or aquifers, where it is naturally filtered. But advanced water purification allows water managers to skip that environmental buffer and pipe it directly into homes.

“As an industry, we have been treating wastewater to very high standards for decades, but we feel the best and most beneficial use is to be able to take that and turn it into potable water,” Preito said.

The need has become more urgent.

Phoenix gets about 40% of its water from the Colorado River. But shortages fueled by climate change and overuse have dropped reservoirs to record lows and triggered cuts for some people who use it.

Forecasters say 2025 is likely to be another dry year .

“We need to be prepared for when things go bad in those watersheds and we need to be able to take care of our customers,” Prieto said.

The city expects the plant will be operational in two years. It’s part of a larger effort with neighboring cities to boost water supplies across the region.

There are similar investments in California , Utah and Colorado . In February, El Paso broke ground on its nearly $300 million Pure Water Center. Tucson is designing a small plant that will open in 2031.

The federal government invested heavily in water-recycling projects during the Biden administration. The Metropolitan Water District of Southern California, for example, was awarded $125 million in federal grants for a large water recycling project, and “after a brief delay, the funding has not been affected by the change in administration,” a spokesperson said.

‘Huge potential,’ but is it safe?

Last month, Arizona took a big step forward when regulators approved new rules allowing cities statewide to start full-scale production for use in people’s homes.

“I see huge potential,” said Randy Mata, with Arizona’s Department of Environmental Quality. He predicted that by 2030, Arizona cities may treat up to 100 million gallons of wastewater a day in this way. “Those are huge numbers,” he said.

It’s roughly 150 Olympic-sized swimming pools of sewage recycled every day.

But officials involved in these projects know that public buy-in is essential. Prieto said the Phoenix water department will give residents ample opportunity to try the water and get used to the idea before sending it into homes.

“It’s an incredible challenge,” he said. “We need to be completely open and transparent with people. We know how safe this water will be.”

The city of Scottsdale, an upscale suburb of Phoenix, has been using the technology to irrigate golf courses and to recharge underground aquifers since 1998.

One key to the process is reverse osmosis. Also known as RO, it forces water through a permeable membrane that catches small particles like dissolved salts and heavy metals.

After reverse osmosis, a treatment with ultraviolet light zaps any remaining viruses or bacteria.

Scottsdale doesn’t have a permit that would allow people to drink the water yet. But a few years ago, local breweries did get permission to make beer with the water.

It was part of a campaign to show people that it was not only safe to drink, but also delicious.

The city’s water quality director Suzanne Grendahl said Scottsdale has been testing its recycled water for years without showing signs of pharmaceuticals, personal care products, herbicides, pesticides and even toxic “forever chemicals.”

“We have no issue,” Grendahl said. “All of it’s gone, and we’re analyzing down to the parts-per-trillion level. She expressed no concerns about consuming the water herself. “Every time we had taste testings out here, I was drinking it. No question at all.”

Drawbacks of recycled water

Mitch Jones, managing director of policy and litigation for Food & Water Watch, has plenty of questions. The group has said that turning sewage into drinking water “ won’t solve our water woes .”

“There are enough concerns that I would — myself — not want to drink the water,” Jones said. “I don’t believe that the technologies have been proven.”

Jones said he’s not convinced there’s enough long-term data to show the water is safe to drink. Utilities still can’t easily test for contaminants like microplastics, and some will be better than others at finding lingering forever chemicals, Jones said.

Plus, the technology is expensive. It uses a lot of carbon-producing electricity and avoids what he sees as the real issue — that cities and farms in arid places are using too much water.

“They do need a solution,” Jones said. “But the solutions that are being put forward are ones that will not actually address the root causes and ultimately can also make the problem worse.”

While it is impossible to completely eliminate the risk, experts like Christy Spackman say recycled wastewater is probably cleaner than the already highly regulated tap water that’s in your home today.

Is recycled water completely pure? “Probably not, but it’s pretty darn close,” said Spackman, a professor at Arizona State University. “Measuring zero turns out to be super tricky.”

Spackman wrote a book called “The Taste of Water.” A while back, along with former grad student Marisa Manheim, Spackman had popsicles made from purified wastewater and encouraged people to try them.

“Initially, when you talk to folks about recycled water, a lot of the reaction is like, ‘Wait, what? You want to do what?’” she said.

Indeed, the “yuck factor” is real.

But Spackman said once people had a chance to learn about the water and try a popsicle for themselves, new questions emerged: “When will we get it?” or “What impact will it have on the environment?”

What may start as revulsion has “the potential to fade,” she said.