August 2, 2012
From toilet to tap: recycled water’s potential to provide clean water for Southern California remains yet to be tapped
By Connie Ge
Windhoek, Namibia. Singapore, Singapore. Brisbane, Australia. El Paso, Texas. San Jose and Orange County, California. Astronauts at the International Space Station. These are among a small handful of places in the world that currently recycle wastewater, from household toilets and sinks, into clean drinking water. The concept of recycled water, or “toilet to tap” is not novel; plants in Namibia have operated successfully since 1968. Also called reclaimed water or grey water, recycled water has been used in the US for agriculture and industry for decades.
Los Angeles too is revisiting recycling water, or “toilet to tap” amidst rising dependency on imported water. 1.3 billion gallons of treated wastewater are discharged into the Pacific Ocean daily. However, once freshwater has been released into the saline ocean water, retrieving it via desalination is extremely energy intensive and thus pales as an efficient method for meeting public demands in comparison to recycling freshwater.
While 97% of the world’s water lies in its oceans, less than 1% is accessible freshwater. Due to global warming, melting icecaps and glacier water are flowing into the oceans at accelerated rates. A basic understanding of the hydrological cycle underscores why conserving freshwater via recycling should be a growing priority for both coastal and inland cities and farm communities in years to come.
Due to rapid desertification of the San Joaquin Valley’s water the past century, on July 24, Gov. Jerry Brown and US Secretary of Interior Ken Salazar announced a $23 billion plan to replenish the depleted, over-pumped farms and cities with water from the Sacramento River. Farmers and environmentalists of northern California voted down a similar plan proposed by Brown three decades ago and are currently protesting the legislation. While water relocation may be necessary to restore depleted farmlands, as a large center of water consumption, Los Angeles has a chance to better sustain itself.
Is recycled water clean enough to drink? Yes. “The technology is remarkable and can treat water to an often higher quality than the water that originally entered the system,” says Brent Haddad, PhD, associate professor of environmental studies at the University of California, Santa Cruz. District managers of the Orange County’s Water District also stated that the recycled water actually exceeded drinking water standards. The Singapore NEWater facilities’ launched a public education campaign prior to the opening of the treatment plant in 2003 explaining in detail the processes used, diminishing public skepticism.
Los Angeles hopes to increase its proportion of recycled local water from 1% to 6% by 2019. The technologies for effective water recycling are within reach: the Hyperion Water Treatment Plant, the largest in southern California once did so, but for some reason stopped. The Orange County Water Treatment Plant was a model for Singapore’s NEWater as well as a new plant in Van Nuys, the Tillman plant. The treatment process includes first microfiltration to remove sediment and organic waste, then reverse osmosis through thin membranes at high pressure to remove microorganisms, pesticides and pharmaceuticals, and finally ultraviolet light and hydrogen peroxide to breakdown remaining compounds. The treated water then percolates through pebbles into an aquifer, where it is pumped up for use several years later.
Access to clean drinking water is a basic human right that all living on planet Earth deserve. While the global South, or so-called “developing” world may sometimes lack infrastructure to meet demands, the global North is also facing considerable freshwater shortages. Not to utilize existing technology would be a waste.
While nervousness at the prospect of recycled water may be anticipated, the conversation itself could have far-reaching effects on deeper attitudes towards resource management. The awareness of what goes around comes around will hopefully invoke unflinching awareness and honesty about where the water we use comes from, where it goes, and increased accountability in regards to water as a shared commodity.
“California county turns to sewer water to increase drinking supplies” New York Times. Randal C. Archibold. Tuesday November 27, 2007.
“From toilet to tap: Psychologists lend their expertise to overcoming the public’s aversion to reclaimed water” American Psychological Association. Sadie F. Dingfielder. September 2004.
“As ‘Yuck Factor’ subsides, treated wastewater flows from taps” Felicity Baringer. New York Times February 9, 2012.
“California governor unveils ambitious water plan” Jim Christie. Reuters.
“Getting it clean: recycling LA wastewater” http://lang.dailynews.com/socal/editorial/water/water.html.
“Recharging the water supply” and “The city’s supplies” spreads by the Los Angeles Times
About the author: Connie Ge is a junior at the University of Southern California working to complete a bachelor of sciences in Earth Sciences.