Water, water, everywhere, . . . Nor any drop to drink. (Samuel Taylor Coleridge, 1797-98)

About 71 per cent of the Earth’s surface is water. According to the World Water Council report, around 1.1 billion people (approximately one in every six people) worldwide do not have access to safe drinking water and around 2.6 billion people do not have improved sanitation facilities [1]. Only 46 per cent of people in Africa have access to safe drinking water. Some of the statistics of disparities in access to water resources in different populations are staggering:

• An American taking a 5-minute shower uses up more water than a typical person uses in a whole day in a developing country slum [1].