… approximately 60% of the 20 million inhabitants live in informal settlements (“slums”); three-quarters of these people do not have access … are 50 people to one toilet seat. Nairobi’s informal settlements are home to at least 30% of the city’s population. On average, 71 people … In a low-density rural settlement, the local eco-system can process human waste, just as it would the wastes from animals in the vicinity, …