Sanitation has long been a critical, but somewhat unfashionable issue in health and rural development, so it is heartening to see the Bill and Melinda Gates Foundation putting their substantial resources behind technological change and innovation in this field with their “Reinvent the Toilet” fair.
A lack of hygienic sanitation and untreated effluent contribute significantly to the pollution of rivers and ecosystems and create an enormous public health issue. Recent measurements of the coliform bacteria levels in the Ganges in India recorded 5,500 mpn/100 ml, well above what is considered safe for farming (5,000 mpn/100 ml), let alone bathing (500 mpn/100 ml) or drinking (50 mpn/100 ml). Every year “food and water tainted with faecal matter cause up to 2.5 billion cases of diarrhea among children under five, resulting in 1.5 million child deaths.”
The minimum requirements for the competition were that the toilets must operate without running water, electricity or a septic system, must not discharge pollutants and should capture energy or other resources. The winning design from the California Institute of Technology certainly fits that bill, as it is a solar-powered toilet that generates hydrogen and electricity.