Hilary Godwin, professora na UCLA no campus de Saúde Pública e do Instituto de Ambiente e Sustentabilidade, junto com outros pesquisadores, realizaram um estudo sobre a segurança do uso de água reciclada, onde afirmam: a tecnologia utilizada para a reciclagem tem-se provado segura e eficaz.
Confira o texto publicado na rede Social “The Water Network” com o link para o estudo:
If you knew that the water you were about to drink was recycled, would you put it down? It’s clear, odor-free, and tastes just like water. C’mon take a taste. You won’t know the difference.
Hilary Godwin, professor at UCLA Fielding School of Public Health and the Institute of the Environment and Sustainability, understands the “ick” factor associated with drinking recycled water. She co-authored a recent study in the American Journal of Public Health touting the health benefits of recycled water. Her study, which she wrote with Brian Cole and Sharona Sokolow, both from UCLA Fielding School of Public Health, found that drinking recycled water is safe, healthy, and good for climate change.
Recycled water, understandably, gets a bad rap. It’s former wastewater or sewage that’s been treated to remove all impurities. “No matter how well such water is cleaned, public health officials remain wary about health risks and public perceptions,” Godwin said.
Perceptions are, however, changing. People are seeing the benefits of using recycled water to irrigate parks, lawns, and golf courses. Godwin argues that using recycled water to maintain green spaces “makes more sense from a public health perspective. Large-scale xeriscaping (which uses drought-resistant plants) reduces green spaces and absorbs sunlight, creating urban heat islands that worsen air quality.”
“The technology behind the water has been proven safe and effective, and with our dire need to conserve in California, more reliance on local supplies seems like a smart and economical path.”
So while acceptance grows for using recycled water to keep green spaces lush, drinking recycled water has been met with resistance. Godwin’s research proves recycled water is the better option over transporting water from faraway sources or using desalinization. “We’re stealing water from hundreds of miles away, burning huge amounts of energy, and producing greenhouse gas emissions,” she said.
Godwin looked at Orange County, CA, and the Orange County Water District where 850,000 people use recycled water. The other residents of Orange County (population 2.4 million) have their water transported to their taps from as far away as the Colorado River, and some get desalinated water.
The study shows recycled water uses half of the energy that it takes to transport water from other sources and about a third of the energy that it would take to desalinate saltwater. Transporting water to the residents emits roughly four million tons of greenhouse gasses a year. “Using recycled water has the greatest potential to decrease energy use and greenhouse gas emissions in California,” Godwin said.
What’s worse is that California is currently in the midst of a five-year drought with little respite in sight as El Niño has failed to deliver the rainfall needed for much of the state to emerge from the dire conditions. Orange County gets about 14 inches of rain a year.
Mike Markus, General Manager at the Orange County Water District (OCWD), agrees. He’s responsible for managing the $480 million Groundwater Replenishment System (GWRS) program, including the construction of seven individual projects; the largest being the Advanced Water Purification Facility, which was expanded last year and now produces 100 million gallons of recycled water per day. In 2020, that number will be upped to 130 million gallons of water per day.
The potable recycled water goes through an extensive purifying system. According to Markus, recycled water passes through microfiltration which removes all suspended solids, bacteria, and protozoa. “After that comes reverse osmosis,” Markus said. “This involves forcing the water across a membrane, which removes other impurities, including viruses, pharmaceuticals, and dissolved minerals. And that’s not all. That water is then zapped with powerful ultraviolet light and treated with a bit of hydrogen peroxide to further disinfect it and neutralize other small chemical compounds.”
Recycled water also saves money. Imported water (water transported from as far away as the Colorado River, which originates in Wyoming) costs $1,000 an acre foot. Recycled water costs $525 an acre foot.
To get over that “ick” factor of using recycled water, OCWD hosts tours where people can see how the water is collected and purified. At the end of the tour they even get to drink the water. “It tastes just like water,” Markus said.
Similar water recycling systems are used in Singapore, parts of Texas, and in other parts of California.
Southern California has also invested heavily in desalinated water, a process that removes salts and minerals from saline water. “The Carlsbad Desalinization Plant is the largest in the nation,” Mark Gold, Associate Vice Chancellor of UCLA’s Institute of the Environment and Sustainability, said. “It costs approximately $2,200 to $2,300 per acre foot, which is much more than recycled water. Another potential large desalinization plant could go in at Huntington Beach and there is talk about one going in the South Bay along Santa Monica Bay. All the projects are extremely controversial because of cost, greenhouse gas emissions, and impacts to aquatic life from the intakes and brine disposal.”
Despite any negatives concerning desalinated water, it and recycled water are both part of an integrated local water approach. “A diverse local portfolio helps during times of drought,” Gold explained.
“The water that comes out of your tap today may have been dinosaur pee.”
Most of Gold’s students were against drinking and using recycled water. “As I learned more about the water recycling and treatment processes in my Environmental Engineering courses, it all began to make a lot more sense,” Tiffany Tran, a UCLA student who has changed her mind on the subject, said. “The technology behind the water has been proven safe and effective, and with our dire need to conserve in California, more reliance on local supplies seems like a smart and economical path for us to take.”
Today, 750 million people worldwide (1 in 9 people) do not have access to safe and clean drinking water—a number expected to increase significantly with the onset of climate change, rising greenhouse gas concentrations, and increasing populations.
Melissa L. Meeker, Executive Director of WateReuse, a non-profit that educates the public on the importance of reusing water and advocates for policy, laws, and funding to increase water reuse throughout the United States, wants to see the rest of the world embrace the use of recycled water.
“Recycled water provides a local, sustainable, and climate-independent water source,” she said. “We cannot wait for drought, population growth, or other urgent issues before considering recycled water. We must protect our precious water resources because there is no new water. The same amount of water that was on the planet thousands of years ago is the same amount of water that is on the planet today. All water on earth is recycled. The water that comes out of your tap today may have been dinosaur pee.”