The current engineering concept for dealing with human waste is to use vast quantities of water to wash it away, preferably into a sewer system, where it may or may not be treated before being discharged into the local river. The “flush and forget” system takes nutrients originating in the soil and typically dumps them into the nearest body of water. Not only are the nutrients lost from agriculture, but the nutrient overload has contributed to the death of many rivers and to the formation of some 405 “dead zones” in ocean coastal regions. This outdated system is expensive and water-intensive, disrupts the nutrient cycle, and can be a major source of disease and death. Worldwide, poor sanitation and personal hygiene claim the lives of some 2 million children per year.
Read More: http://grist.org/article/2010-11-03-reducing-urban-water-use/