ABSTRACT
Nearly 1 billion people lack access to any form of improved water supply within 1 km of their home [1] (Figure 24.1). The poorest 4 billion people collectively spend more than $20 billion per year on water collection and treatment. This consists of collecting water from surface sources often polluted with unknown amounts of animal waste, chemicals, heavy metals, and biological agents; partially treated piped water; shared community resources, individual water puriers, and mobile water vendors [2].
