Ecodesign: The Bottom Line
Every year, on average, each of us excretes 50 litres of feces, rife with pathogens and heavy metals. Multiplied by Earth’s population of 7 billion — and rising — that constitutes not so much an elephant in the room as a herd of mammoths. Sustainable solutions are urgently needed, particularly for the 2.6 billion people who lack adequate sanitation and the 1.1 billion practicing open defecation. Rich countries, meanwhile, often have hidden sanitation issues of their own.
There is no single design solution to sanitation. But there are universal principles for systematically and safely detoxifying human excreta, without contaminating, wasting or even using water. Ecological sanitation design — which is focused on sustainability through reuse and recycling — offers workable solutions that are gaining footholds around the world. Nature explores four of these in a special feature examining the work of Peter Morgan in Zimbabwe, Ralf Otterpohl and his team in Germany, Shunmuga Paramasivan in India, and Ed Harrington and his colleagues in California.