ABSTRACT
Even today, about 900 million people are without access to clean drinking water (WHO/UNICEF 2010). In sub-Saharan Africa, about 70 percent of the population work in subsistence agriculture, highlighting the importance of suffi cient and clean water supplies (Allen and Thomas 2002). Water is a source of economic activity, crops cannot thrive without it, but it can also contain bacteria, protozoa, viruses and parasites causing water-borne diseases, such as cholera, bilharzia and typhoid fever.
