Water quality in shallow wells of George township in Lusaka, Zambia and its possible health effects

Abstract

Lusaka sits on a limestone rock formation which makes recharge as well as pollution of groundwater very easy due to the presence of channels created by solution weathering. Informal/unplanned settlements where waste disposal facilities are non-existent are potential groundwater contamination areas. George Township area of Lusaka is an unplanned or informal settlement where supply of water is provided by Lusaka Water and Sewage Company through stand pipes. However, it was found that at least one percent of a sample of three hundred and fifty people interviewed in 2001 indicated that they entirely depended on shallow wells for their domestic water supply despite the availability of an ultramodern water supply infrastructure provided through a JICA grant. The quality of the water in the shallow wells has been largely unknown. A study to monitor the quality of the water in the shallow wells in the area was instituted in April 2006 and ended in April 2007. Results obtained do indicate that the water is highly contaminated with waste materials especially human waste. The source of this contamination seems to point to the pit latrines which are the method of choice in the disposal of human excreta in the area. With high levels of total coli forms (TC) as well as fecal coli forms (FC) and Escherichia coli, human health problems such as those related to gastro intestinal problems including diarrhoeal diseases, are a reality in the area. Further, from the preliminary results, it seems that metals such as Lead and Cadmium are also in concentrations above acceptable levels. These have serious health effects such as damage to the nervous system (Lead) as well as those related to damage of the kidneys (Cadmium). The "blue baby" syndrome in neonates arising from taking water with high nitrate concentrations such as the one in George Township area seems a real possibility. Measures to reduce groundwater contamination from pit latrines are necessary. Those proposed range from design and construction of pit latrines to use of other types of disposal facilities as well as education of the communities. Other measures relate to treatment of water at household level to make it suitable to drink.