In August 2020, a group of 50 beer lovers in Calgary—along with drinkers videoconferenced in from Edmonton and Ottawa — had a communal sip of a limited-edition brew of Village Brewery’s Blonde. This one-off was made from purified water that had only recently been wastewater flowing from the city’s toilets and sinks.
“There wasn’t a comment from a single person who said that the beer tasted strange or funny,” says Leland Jackson, PhD, scientific director of Advancing Canadian Wastewater Assets, which runs research projects out of a Calgary wastewater treatment facility and partnered with Village Brewery and water tech company Xylem to make the beer. The water used by the brewers went through an additional four-step purification process after it was scooped from the treatment plant.
Some compared the ale with Village’s regular Blonde. “People were amazed that you could not tell the difference,” says Jackson, a professor of ecology and evolutionary biology at the University of Calgary who also brews his own dark ales at home (with regular water).
This quaff was not entirely about pleasing beer nerds—it was also illustrating the feasibility of direct potable reuse (DPR), or recycling wastewater into drinking water. In southern Alberta, where Village Brewery is located, a dearth of fresh water means communities and companies can’t get licenses to draw more water from the area’s rivers and instead must swap water rights. Across the border, many parts of California struggle to find enough fresh water. Huge swathes of the southwestern United States face severe shortages.
North America’s cities keep growing, but there’s less fresh water for their residents. “With climate change, we’re expecting less precipitation. We’re not likely to have more water. We need to get creative and do more with what we’ve got now and possibly in the future,” says Caroline Scruggs, PhD, associate professor in the School of Architecture and Planning at the University of New Mexico.
“Direct potable reuse is going to be the future for many communities. We have the technology.”
Recycling drinking water could help cities along the Eastern Seaboard deal with depleted aquifers — which also cause the land to become unstable — and saltwater intrusion on freshwater resources. Plus, when regions create a closed loop for water, they’re not discharging waste for other cities to contend with or impacting nature by warming waterways or adding nutrients that lead to algae growth or other problems.
Projects involving DPR and its close cousin, indirect potable reuse (IDR)—in which an environmental buffer, such as an underground aquifer or a reservoir, holds recycled water for a time—are already underway in the United States, and they already feature in the strategic plans for numerous municipalities. “Direct potable reuse is going to be the future for many communities,” says Patricia Sinicropi, executive director of the WateReuse Association in Washington, D.C. “We have the technology.” The question is not whether it will become more widespread, but when — and how to endear people to the idea.
Potable reuse is growing 15% a year in the United States, with initiatives at various stages in places like Scottsdale, Arizona; San Diego and Orange County, California; Cloudcroft, New Mexico; and El Paso, Big Spring, and Wichita Falls, Texas. But drinking water that was once sewage — dubbed “toilet to tap” by detractors — still freaks some people out. “You really think during a pandemic that I want to drink beer from sewage aka treated water? Absolutely no more of your products for me and my friends,” wrote one non-fan on Village Brewery’s Facebook page. “Regardless if this is the only beer that is experimented with, this turns my stomach for your whole product line,” said another.
Many of the new projects in the United States rely on longstanding but ever-improving technology for the multiple-stage cleaning process, including ultrafiltration, advanced oxidation (which includes using ozone and ultraviolet treatment), and reverse osmosis. The fundamental concept of potable reuse, however, has been around for decades.
Water scarcity inspired one region of Namibia to start using DPR in 1968. Singapore has been using it since 2002. The International Space Station has been collecting wastewater, sweat, and breath moisture from people and lab animals and converting it into drinking water since 2005. “The system sounds disgusting, but recycled water on the ISS is cleaner than what most Earthlings drink,” NASA wisecracks on its website.
DPR is different, but not that different, from how we already generate drinking water. Usually, municipalities collect water from an aquifer or river, purify it, and send it through pipes. Then wastewater from toilets and taps goes through primary and secondary treatment, and the city sends that semi-clean water back into nature. Maybe it finds its way underground for decades of natural cleaning; if it’s sent into a busy river, such as the Mississippi or the Colorado, it becomes the water source for downstream neighbors. “People are afraid of DPR because they don’t really understand what the status quo is,” Scruggs says.
Regular water purification plants actually put water through fewer and less stringent steps than reuse facilities. In fact, water processed through DPR ends up so clean that municipalities have to add back salt and minerals to give it taste. “If you explain what the status quo is and what planned versus unplanned potable reuse is, people are very accepting,” Scruggs says. Her research has found that citizens approve recycling plans when they’re consulted from an early stage. It also helps if they live in an arid region.
“If you’re in California and you’re right beside the ocean and you have palm trees all around you, water scarcity is not on your mind,” Scruggs says. DPR is also a tough sell in Alberta, where Jackson lives. “In Canada, there’s a perception that we have lots of clean water and we’re always going to have lots of clean water.”
Cities building potable reuse plants budget for public outreach. El Paso, which is planning a DPR facility that processes 10 million gallons per day, welcomed the public to view the pilot plant it ran for nine months in 2016. Designs for the $90 million plant include a visitor touring area. “We are sitting in a good place, and the community has accepted it,” says Christina Montoya-Halter, communications and marketing manager for El Paso Water. “We don’t want to rest on our laurels. We want the public to understand the technology and why we need it.”
In San Diego, a 1991 potable reuse proposal got scrapped due to public backlash — the phrase “toilet to tap” may have originated there. “Then we had a drought and they changed their mind,” says John Stufflebeam, assistant director of Pure Water (San Diego’s new potable reuse project) and technical services for the city’s public utilities department.
“We’re used to thinking of wastewater as a waste, but it’s not — it’s a valuable resource.”
With a new plan to process 30 million gallons of water per day via IDR by 2035, San Diego launched an aggressive marketing campaign that included ads on buses and in malls. A demonstration facility that produces 1 million gallons per day, launched in 2011, offers tours. (They’re currently virtual.) “The people who do the public relations on this tell me that they’ve never seen an issue that you can change people’s minds so quickly when you tell them the facts,” Stufflebeam says.
In addition to public perception, potable reuse has one other serious obstacle: cost. In El Paso, purifying water from many of its current sources, including the Rio Grande, costs just $300 per acre foot (the favored way to measure water costs), while DPR will run $1,200. “El Paso is a low-income community. We don’t want to make this difficult for our ratepayers,” Montoya-Halter says. So El Paso Water is developing its project slowly with the help of grants. In 2019, it received $3.5 million from the U.S. Bureau of Reclamation for design. Montoya-Halter suspects it will take many grants over several years to get the facility built.
For San Diego, IDR makes sense financially, thanks to a trade-off. For years, the city has been allowed to dump minimally treated wastewater into the Pacific but was under pressure to start doing secondary treatment before disposal. Over the past several years, instead of upgrading its wastewater plants, it has negotiated with governments and environmental groups to reduce how much wastewater it dumps by doing IDR. The new Pure Water facility will cost millions, but it’ll be a wash. “It’s a better way to accomplish what we had to accomplish anyway,” Stufflebeam says.
Another barrier to DPR is its single waste product: the brine of salt and contaminants left over after reverse osmosis. Coastal cities can dispose of this waste in the ocean, but landlocked El Paso has nowhere to dump it. For now, the city is working with university researchers on the problem. “Maybe by the time this plant actually gets built, we’ll have some better solutions,” Montoya-Halter says. Sinicropi confirms that this is the focus of numerous research projects.
Many regions also have to tussle with state regulators over approving the safety of their recycled water and over water rights, as many regions require cities to release as wastewater a ratio of what they take in to maintain water levels. “It’s a paradigm shift,” Sinicropi says.
Bolstering municipalities’ efforts to convince residents, find money, and shift laws is the emerging support of the Environmental Protection Agency and its National Water Reuse Action Plan, which released a key implementation document in February 2020. It offers a framework for more federal leadership and increased collaboration between all levels of government. So, expect to sip some directly cleaned wastewater via a mug of beer or right from a tap sometime soon. “I think DPR will catch on,” Scruggs says. “Because there aren’t any other options, and we’re used to thinking of wastewater as a waste, but it’s not — it’s a valuable resource.”