A large proportion of the world’s population currently lacks access to improved sanitation. The current status quo of open pit latrines is not a suitable answer because they do not hygienically separate waste from human contact, thereby facilitating the spread of diseases. Recent estimates have shown that approximately 1.5 million deaths children under the age of five could have prevented with proper sanitation.
Inspired by the Global Sustainable Aid Project's Micro-Flush Toilet and adapted to meet Bolivian needs by harnessing local materials, our units filter a waste in a digester chamber that separates solids and liquids. Solids are composted in an aerobic process by local earthworms. Liquids are processed naturally in a soak hole – a micro version of a rural leaching field in the US. These units only require one cup of grey water to flush. Every 2 years, the rear cover of the digester is removed and an organically rich compost is harvested for use in agriculture.
The most important feature is that this unit successfully separates waste and human contact by storing waste in a sealed digestion chamber. Another environmentally-friendly feature is having earthworms decompose the waste to produce agriculturally-useful material. We have built 10 such units to date in various communities throughout La Zona Sur. To ensure long-term sustainability, we have also trained several masons to construct the units without our help, and taught families how to use these facilities and other sanitation techniques.