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https://greywateraction.org/composting-toilets/

The modern-day sewer system has failed. In the United States, our clean water infrastructure was rated a D from the American Society of Civil Engineers (2013). Sewage overflows cause beach closures, spread illnesses, and contaminate the environment.  And this is happening in places that actually have sewage treatment… most of the world does not and untreated sewage more quickly contaminates the environment, and is the source of illness and death for millions of people, a child dies every 21 seconds as a result of inadequate sanitation (UNICEF, WHO 2009)

Fortunately, we don’t need costly sewage plants or septic systems to render human waste into a harmless substance that, instead of being a problem, is a solution to problems of water shortages, water pollution, and reliance on chemical fertilizers. This is ecological sanitation, taking care of our human sanitation needs in a way that is helpful, rather than harmful, to the environment.