ABSTRACT
Over one billion people lack access to a basic supply of clean drinking water, defined by the World Health Organization (WHO) as (low) 20 litres/day within 1 km of the home. WHO estimates that 2.4 billion people lack adequate sanitation facilities. A child dies every fifteen seconds from diarrhoea, largely caused by contaminated water or poor sanitation; this death toll exceeds the ravages of HIV/AIDS on children.1
