Department of Earth Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia; School of Geosciences, University of the Witwatersrand, Private Bag X3, P.O. Box Wits 2050, Johannesburg, South Africa
Haile, T., Department of Earth Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia; Abiye, T.A., School of Geosciences, University of the Witwatersrand, Private Bag X3, P.O. Box Wits 2050, Johannesburg, South Africa
Geo-environmental assessment and geophysical investigations were carried out over the only functional municipal solid waste disposal site of the city of Addis Ababa, Ethiopia, known locally as Koshe. The accumulated wastes from Koshe have impact on the surrounding human and physical environment since the disposal site was not designed. The study deserves emphasis because the city of Addis Ababa currently obtains a considerable portion of its domestic water supply from a well field developed not much farther from and along a groundwater flow direction in relation to the waste disposal site. It was found out that the leachates from the site contain high concentration of biological oxygen demand, chemical oxygen demand, chloride and sulphate besides high concentration of cobalt, nickel and zinc in the surrounding soils. The geophysical results have mapped weak zones and near-vertical discontinuities that could potentially be conduits for the leachate from the wastes into the deep groundwater system. Further, a zone of potential leachate migration from the landfill was identified from the electrical models; the location of this zone is consistent with the predicted direction of groundwater flow across the site. The results further suggested that the open dump site tends to cause increasing amount of pollution on the surrounding soil, surface and ground waters. Furthermore, it was observed that the Koshe waste disposal site has grown beyond its capacity and the poor management of the open dump landfill has reduced the aesthetic value of the surrounding environments. The need to change/relocate the existing waste disposal site to a more suitable and technologically appropriate site is emphasized. © 2012 Springer-Verlag.
Aesthetic value; Biological oxygen demand; Deep groundwaters; Disposal sites; Domestic water supply; Electrical models; Environmental pollutions; Ethiopia; Ground water systems; Groundwater flow directions; High concentration; Koshe-Addis Ababa; Leachate migration; Leachates; Open dump; Physical environments; Sulphates; Surrounding environment; Surrounding soils; Waste disposal sites; Biochemical oxygen demand; Chlorine compounds; Cobalt; Environmental impact; Geophysics; Groundwater; Groundwater flow; Leachate treatment; Municipal solid waste; Soil pollution; Waste disposal; bioaccumulation; concentration (composition); environmental assessment; environmental impact; groundwater flow; heavy metal; landfill; leachate; municipal solid waste; numerical model; soil pollution; sulfate; surface water; vulnerability; waste disposal; water pollution; water supply; Addis Ababa; Ethiopia