Down the Drain and Back
According to the US Environmental Protection Agency (USEPA), recycled waste water is defined as treated waste water for beneficial uses.
Recycled wastewater is distinguished according to different levels of treatment and end uses. Gray water is wastewater from residential, commercial and industrial bathroom sinks, bath tub shower drains and clothes washing equipment drains. The water is typically disinfected and filtered before returning for local landscape irrigation. Recycled waste water with very advanced chemical treatment, filtration and disinfection can be used to replenish groundwater aquifers and surface water aquifers destined for human consumption. Water used in cooling processes at industrial facilities can be recaptured and reused for the same purpose again. Unplanned recycled waste water is treated waste water from a city upstream that has entered into a downstream city’s water source. Water upstream may be used, treated and reused few to many times before ending up downstream.
According to a recent study by the National Research Council, the health risks associated with using recycled waste water is no more than that of existing fresh water supplies. This is a complete turn around from the previous study by the same group in 1998, which concluded that recycled waste water should be “an option of last resort” for human consumption. The study compared pathogen and chemical contaminant levels between water from a conventional source and water from aquifers partially recharged with treated sewage and founded no difference in health risks between the two and, in the case of pathogen levels, may be lower.
Recently, a research team at the University of Southern Maine surveyed about 2,700 individials across 5 cities in the US about their willingness to drink water recycled from waste waters. 38% were willing, while 13% were not willing and 50% were unsure. Despite the lack of support, participants of the survey were more willing to drink the recycled water if it had been stored in aquifer than if it had been directly supplied from the treatment plant.
For years, many water-strapped cities and towns in Western US have been implementing water recycling technologies and policies to get the most out of their water supply and to meet future water demand.
– Las Vegas, Nevada currently discharges its treated wastewater into Lake Mead, which also supplies water for Southern California and much of the Southwest.
– Los Angeles, California boasts two waste water treatment plants that provide recycled waste water for beneficial uses within the City. The Glendale Water Reclamation Plant treats over 20 million gallons of water every day, while the Donald C. Tillman Reclamation Plan treats about 40 million gallons of water per day. Both supplies irrigation water for City-managed golf courses, parks and landscaped areas.
– Last year, while facing a prolonged drought with no end in sight, Big Spring, Texas, begun constructing a water treatment plant that will treat and redistribute about 2 million gallons of water back to Big Spring and three nearby cities for residents to use.
– In 2008, Tucson, Arizona adopted an ordinance that requires all new single family or duplex residential units to install water piping features that allow or can allow for the recapture and reuse of gray water.
– In 2008, Inglewood, California completed construction of 2,700 water piping to and from Ashland Park, landscaped areas of the California Department of Transportation (CalTrans) buildings and the water source. After retrofitting was completed in 2009, water expelled from municipal uses has been diverted for landscape irrigation of the Park and landscaping at the CalTrans buildings.
– In late 2007, the Orange County Water District of Orange County, California began treating the region’s municipal waste wasters with an intense mix of ultraviolet light, filters, screens and chemicals. The recycled product is injected underground to form a barrier against seawater intruding into groundwater and to replenish aquifers that supply water for the region’s residents.
– During the same year in San Diego, California, the City Council, anticipating future water demand, approved a proposal to incorporate treated waste water to replenish the city’s reservoir, but it was rejected by the mayor. The reasons being high costs and personal aversion to the idea.
The recent trends in water management across states in Western U.S. show that cities are pursuing alternative water conservation strategies more progressively and openly. Although it is likely that no one will ever feel completely at ease with drinking perfectly drinkable recycled waste water, protecting our precious water supply is more important than protecting our feelings.
Archibold, Randal C. “From Sewage, Added Water for Drinking.” 27 November 2007: The New York Times. http://www.nytimes.com/2007/11/27/us/27conserve.html. Last Accessed 10 February 2012.
Boxall Bettina. “Report Backs Greater Use of Recycled Wastewater.” 2012 January 11: Los Angeles Times. http://articles.latimes.com/print/2012/jan/11/local/la-me-water-reuse-20120111. Last Accessed 10 February 2012.
City of Los Angeles Department of Water and Power. “Water Reclamation.” http://wsoweb.ladwp.com/Aqueduct/historyoflaa/reclamation.htm Last Accessed 10 February 2012.
Rettner Rachael. “Would You Drink Recycled Sewage? Why It Grosses Us Out.” 8 September 2011: Live Science. http://www.livescience.com/15955-recycled-water-sewage-psychology.html. Last Accessed 10 February 2012.
Stepney, Chloe. “More Western Towns Adopt “Toilet to Tap” Strategy to Water Conservation.” 22 August 2011: The Christian Science Monitor. http://www.csmonitor.com/USA/2011/0822/More-Western-towns-adopt-toilet-to-tap-strategy-to-water-conservation. Last Accessed 10 Feb 2012.
West Basin Municipal Water District. “Harbor/South Bay Water Recycling Project.” http://www.westbasin.org/water-reliability-2020/recycled-water/current-projects. Last Accessed 10 Feb 2012.