Because drinking water could include recycled wastewater

The idea of ​​drinking water that has recently been sewage swirling in the toilet, shower drain, or kitchen sink can seem rather unpleasant. But experts say there’s actually nothing to be picky about – and it could be coming to your state and city soon.

It is a water recycling method known as direct potable reuse, or DPR, which sends highly treated wastewater almost directly to a potable water system for distribution to communities. It is legal in Texas and on a case-by-case basis in Arizona. Many other states are formulating regulations to legalize it as well, including California, Colorado, and Florida.

The water produced by DPR meets federal drinking water quality standards, experts say. And there is a growing movement to urge people to warm up to the idea of ​​DPR and other wastewater recycling methods, which were once scornfully labeled “toilet-to-tap”.

“People need that mindset shift, forgetting where water comes from and focusing more on how clean it is when it’s in front of you,” says Dan McCurry, professor of civil and environmental engineering at the University of Southern California, to CNBC Make It.

Recycling of wastewater can help avoid a shortage of drinking water

The process may not sound appetizing, but DPR can prove invaluable when drinking water becomes scarce.

Climate change alters patterns of rain and snowmelt, which send less fresh water to natural and crucial drinking water sources like the Colorado River. Lake Mead and Lake Powell, all of which face severe water shortages in extreme drought conditions. Growing populations that require more drinking water will only stretch those thinner sources, making methods like DPR even more essential.

So far, two cities in Texas, Big Spring and Wichita Falls, have used DPR to bolster their drinking water supplies. El Paso is planning to follow suit, along with big cities like Los Angeles and San Diego once state DPR regulations are in place.

Wichita Falls has been implementing the DPR for about a year, starting in July 2014, as an emergency solution to an excruciating five-year drought. Chris Horgen, the city’s public information official, says DPR has produced 5 million gallons of treated water every day for the city, which is a third of the drinking water distributed to the taps.

“The state was so close to delivering bottles of water to us in that past year,” says Horgen. “This is what would have happened without DPR.”

In El Paso, DPR is not yet active, but the project is ongoing with the aim of building a long-term sustainable drinking water supply. Diversifying the city’s drinking water sources could better prepare it for severe droughts that threaten natural sources like river water, says Christina Montoya, communications and marketing manager at El Paso Water Utilities.

“It’s a way to make sure El Paso will thrive in 50 years,” he says. “We can’t just plan when an emergency occurs. We have to plan all the time for the future.”

Wastewater recycling is nothing new

If you are still feeling picky about the DPR, know that this is nothing new: there may already be some recycled sewage in your drinking water. Several cities in the United States have for decades used a similar system called indirect potable reuse, or IPR.

In such a system, wastewater is treated in a wastewater treatment plant, which cleans it to a standard-compliant level for irrigation or irrigation of land and crops. The water is then sent to an advanced purification facility, which McCurry says cleans the water even more, typically putting it through a three-step process that ensures it meets or even exceeds state and federal standards for water quality. drinking water.

At this point, the water is clean. However, it then goes into an “environmental buffer” such as an underground aquifer, where it can take months or even years to undergo further filtration. Finally, it goes to a drinking water distribution system, McCurry says.

DPR eliminates that stage of the environmental buffer, eliminating time, costs and energy from the process, McCurry says. In some cases, the water is sent directly to the taps. In other cases, it is mixed with raw water, such as lake water, before entering the distribution.

Research shows that advanced purification facilities can consistently treat wastewater to safe drinking standards without that extra step of an environmental buffer, which “isn’t really necessary,” says Patricia Sinicropi, executive director of the industry trade association. water WateReuse.

“That technology can really take any type of water from any source and purify it to the point where the average consumer will have a good experience drinking it,” he says.

How cities are eliminating the “crap factor”

More than two decades ago, political rhetoric and media sensationalism sparked strong public resistance to the concept, resulting in abandoned projects in cities like Los Angeles. A 2015 survey of 2,000 people in the United States found that 13% strongly refuse to try recycled wastewater, 38% are uncertain, and 49% are willing to try it.

This is why some cities are starting trials earlier.

San Diego operated a small-scale advanced purification facility from 2009 to 2013 that successfully demonstrated that DPR can treat wastewater to safe drinking water standards. That demonstration facility did not distribute water to the taps, making it perfectly legal, and allowed the public to visit and test the water produced.

In El Paso, a demonstration facility successfully ran its course for eight months in 2016, according to Montoya. Shortly thereafter, the city obtained approval to develop a large-scale facility for the execution of the DPR, which is likely to be completed in 2026 and will produce around 10 million gallons of clean water per day. 96% of citizens said they were in favor of the city’s DPR plans after visiting the demonstration facility.

“We know the technology can treat wastewater in some of the purest waters out there. But it’s that challenge of public acceptance for other parts of the country,” says Montoya. “People just have to understand how important it is.”

Los Angeles has a similar plan to avoid repeating history. Jesus Gonzalez, head of the recycled water program at the Los Angeles Department of Water and Electricity, says the city will open a demonstration facility in the heart of the city by the end of 2024 to serve as “proof of concept “, after California legalizes the DPR and finalizes the regulations by the end of 2023.

“We want to eliminate the ‘crap factor’ or the negative perception of people,” he says.

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