The suitability of shallow hand dug wells for safe water provision in sub-Saharan Africa: Lessons from Ndola,Zambia |
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| Institution: | 1. Department of Geography University of Otago, PO Box 56, Dunedin, New Zealand;2. School of Tourism and Hospitality, Faculty of Management, University of Johannesburg, Johannesburg, South Africa;1. School of Information Engineering, Inner Mongolia University of Science and Technology, Baotou, Inner Mongolia 014010, PR China;2. The Fourth Affiliated Hospital of Inner Mongolia Medical University;3. Inner Mongolia Branche Bank of Construction Bank of China, Baotou, Inner Mongolia 014030, PR China;4. School of Computer Engineering and Science, Shanghai University, Shanghai 200444, PR China;1. College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, People’s Republic of China;2. School of Life Sciences, Shandong University of Technology, Zibo 255049, People’s Republic of China |
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| Abstract: | Many informal communities within urban areas in sub-Saharan Africa are heavily reliant on shallow hand-dug wells for water, but these are vulnerable to contamination from a range of sources. This paper assesses the heavy metal contamination and total coliform risk of unprotected shallow wells in Ndola, Zambia – a city struggling with contaminated surface waters from both bacteriological and potential mining waste products. One hundred and twenty three shallow wells were sampled across the Ndola, and these encompassed the three main lithologies of the city. All wells lacked an internal casing, however, some wells did have covers and/or pavements surrounding the wells, albeit of dubious efficacy. Despite the lack of protection, the quality of water used abstracted from these wells generally met the World Health (WHO) guidelines for heavy metals (with the exception of Al) and total coliforms (although, this was highly variable). The quality of shallow well water varied across Ndola relative to the underlying geology, where total recoverable concentrations were typically lowest in granite-gneiss. Dissolved load concentrations were lowest in dolomite-limestone, highlighting the role of aquifer geology in acting as a buffer against metal toxicity. Our study illustrates that shallow wells, within the appropriate geological units, may provide a safe and reliable source of drinking water. Well protection is, however, needed to ensure that the proliferation of shallow well use does not lead to regional degradation of the groundwater resource. There is an immediate need to invest in promoting internal well casing during the construction of shallow wells, concomitant with investment and education into protecting wells at the surface, despite the current relatively low level of contamination in wells without protection. |
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| Keywords: | Shallow wells Hand dug wells Heavy metals Groundwater Africa |
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