IRON AND MANGANESE LEVELS OF GROUNDWATER IN SELECTED AREAS IN IBADAN AND FEASIBLE ENGINEERING SOLUTIONS

Abstract

This research work focused on the assessment of iron and manganeselevels of groundwater in selected areas of Ibadan, South West Nigeria, andprovides feasible engineering solutions for community use. The study wascross-sectional and analytical in design. Water samples were collected froma total of 93 wells (shallow and deep) and 27 boreholes within high, mediumand low density areas of Ibadan. In addition, 18 soil samples were collectednear these water sources at a depth of 15 cm. Water and soil samplescollected were anlaysed for iron and manganese using standard methods(American Public Health Association). The pH values of waters from wellsand boreholes for high, medium and low density areas were within thepermissible limits of World Health Organisation (WHO), StandardsOrganisation of Nigeria (SON). All (100.0%) wells in the medium and lowdensity areas had iron concentration exceeding the WHO and SONrecommended limit while all (100.0%) boreholes in high, medium and lowdensity areas had Fe concentrations exceeding the permissible limits. Most,71.4% of wells and 81.8% boreholes in the high density area had manganeseconcentrations exceeding the SON standards while 35.7% of wells and 9.1%boreholes in this study area had Fe concentration exceeding WHO guidelinevalue. An inverse correlation existed between pH and Fe concentrations ofwells in high density area (r=-0.646, p< 0.01) while age of the wells in highdensity area was found to be significantly related to Mn concentration (r=0.382, p< 0.05) showing the older the well, the lower the value. Most of thewells and boreholes in the high density area had high manganeseconcentrations. Proper and hygienic maintenance of wells and boreholes is necessary and storage, and use of water filter may be applied to reduce Feand Mn concentrations at household level before use.