The provision of safe drinking water is a fundamental right of basic health and an extremely high priority of the Malawi Poverty Reduction Strategy. Approximately 50% of illnesses in Malawi are solely due to water-related diseases with only 37% of Malawians having access to safe drinking water. Within Malawi a large percentage of the population people rely on local groundwater sources for their water needs. These can be deep boreholes or shallow wells, the latter are normally found in poorer communities as they are the least expensive to construct. Over time water from these sources can be contaminated leading to fatal consequences. Previous monitoring of the quality of water from boreholes and shallow wells has been irregular, with the focus being mainly on boreholes. Information on seasonal water quality changes in shallow wells used by rural communities in Malawi has generally been lacking. In certain regions as the water percolates through the soil harmful physical, biological and chemical constituents become contained in the water making it unsuitable for human consumption. Conventional water purification systems are prohibitively expensive for developing countries. The extent of pollution in the shallow wells together with innovative, sustainable and economical solutions for rural villagers needs to be developed.
To date, this research has developed a water quality inventory for 52 shallow wells (42 covered, 10 open) from six districts in Southern Malawi. Over 2,700 samples were analysed for chemical, microbiological and physical contamination between 2005 and 2007. Water quality results indicated that shallow well water is heavily polluted with both total and faecal coliforms. The pollution level was higher in the wet season especially soon after the on-set of the rains, i.e. October/November, compared to the dry season in all the districts. About 94% of all the wells tested failed to meet the total coliform guideline value of 50 colony forming units (cfu)/100 ml for untreated drinking water in the wet season, while about 80% of the wells failed in the dry season. Approximately 83% of all the wells tested failed to meet the faecal coliform guideline value of 50 cfu/100 ml in the wet season, while about 50% of the wells failed in the dry season. Faecal coliforms values in excess of 1,000 cfu/100 ml were noted in 13% of the samples indicating gross contamination and the probability of pathogens being present. The majority of chemical and physical parameters, in most of the wells, were found to be within the recommended limits except for a small number of wells where fluoride and turbidity exceeded the guideline values.