saneamento basico

É hora de tomar um refresco e superar a “repulsa” pela água reciclada

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. ​

Still, hesitant?

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 ​Niñ​o 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.​” ​

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