The role of handpump corrosion in the contamination and failure of rural water supplies

01.01.2016
There has been much discussion over many years regarding the origin of elevated iron concentrations in rural water supplies in sub-Saharan Africa and Asia. High iron concentrations are often assumed to be naturally occurring in groundwater, despite several studies over the last 30 years which also point to the role of handpump corrosion in aggressive groundwater. Handpump standards specify that galvanized iron pump materials should not be used in groundwater due to the risk of corrosion, yet this advice is not always followed. High iron concentrations, whether naturally occurring, or present as a result of corrosion, have an impact on taste, odour, and appearance of water and can promote the growth of unpleasant iron metabolizing bacteria. These effects often result in the abandonment of boreholes, sometimes only a year old, and a return to unprotected and unsafe water sources. Where boreholes are not abandoned, the effects of corrosion can cause pump materials to degrade to the point where the pump becomes inoperable. These outcomes are clearly inconsistent with the provision of sustainable water supply services as a fundamental human right. This paper provides a synthesis of work undertaken in this area over the last 30 years and recent practical experience of WaterAid in investigating these problems in water supplies in north-eastern Uganda.