In Southern California, where fresh water supplies can be quite low, Orange County has a system in place that has produced water (in addition to electricity from burning methane as the waste decays) for several years. The New York Times provides a nice description of how the water is actually treated:
First, wastewater is filtered through string-like microfibers with holes smaller than bacteria and protozoa. Then it goes through reverse osmosis, an energy-intensive process forcing the water through plastic membranes that remove most molecules that are not water. Finally, it is dosed with hydrogen peroxide and exposed to ultraviolet light, a double-disinfectant process. The result is roughly equivalent to distilled water.
In fact, most tap water and much of the bottled water sold in the United States is distilled water.
Arguably, reusing water in this manner would not be acceptable to the masses if it is not safe. This is where the National Academy of Sciences comes in to play. A recent report stated that with the “recent advances in technology and design, treating municipal wastewater and reusing it for drinking water, irrigation, industry, and other applications could significantly increase the nation’s total available water resources, particularly in coastal areas facing water shortages.” Furthermore, “the reuse of treated wastewater, also known as reclaimed water, to augment drinking water supplies has significant potential for helping meet future needs. Moreover, new analyses suggest that the possible health risks of exposure to chemical contaminants and disease-causing microbes from wastewater reuse do not exceed, and in some cases may be significantly lower than, the risks of existing water supplies.”
Will the public buy into it? Given the explosion in bottled water, it may be difficult. I wonder what Elizabeth Royte would say about it.
[Image source: John Fielding]