I have held off on blogging about USA Today’s cover story (March 3, 2011) for a week because of the yuk factor. Your students will moan you when 
Clearly something needs to be done. One-eighth of the world (884 million people) still lacks safe drinking water…and its not just in remote/poor regions. Singapore, dependant on Malaysia for the strategic resource of water, has built recycled wastewater plants that now serve 1/3 of its people. Orange County, CA (which has to import water from the northern part of the state and Colorado), uses treated wastewater to serve 1/5 of its 2.4 million residents. The Northern Virginia suburbs of D.C. use purified sewage for 5% of the area’s drinking water.
But other parts of the world, from San Diego to Australia, have had to back away from recycling plans amid public outcry. “The gross out factor is a big barrier”, admits a UC prof. Despite the nickname —“toilets to tap”–only about 10% of household wastewater comes from toilets, while the rest is from showers, sinks, and laundry. And the resulting water is often cleaner than what you would buy in a store, as the EPA’s standards are very strict.
Here is briefly how it works: first microfiltration traps bacteria; then reverse osmosis blocks salt, drugs, and viruses; and finally, ultraviolet light and hydrogen peroxide kill organics. Besides alleviating drinking water shortages, the technology is used for recycling in factories (see our video on Frito-Lay’s sustainability), for agriculture, and it means less waste discharged into the ocean.
Discussion questions:
1. Why is recycling water an OM issue?
2. What are the advantages of this method of reclaiming wastewater?