Contaminant Delineation of a Landfill Site Using Electrical Resistivity and Induced Polarization Methods in Alice, Eastern Cape, South Africa

S Mepaiyeda,O Gwavava,K Madi,L Sigabi,C Baiyegunhi

doi:10.1155/2019/5057832

Abstract

A combination of electrical resistivity and induced polarization methods were applied to a solid waste landfill in Alice, Eastern Cape, South Africa to delineate the lithologic layers and locate possible leachate plumes. Resistivity and IP data were collected along six profiles; VES on two and the dipole-dipole configuration was used in the rest four. The result shows a 4-layered earth system with a shallow depth to the top of the bedrock (<10 m). Contaminants ranging from unsaturated waste with high ion content to dense aqueous phase liquid contaminants, characterized by low resistivity (34–80 Ohm-m) and low chargeability values (0.05–5.75 ms). The contamination was interpreted based on resistivity/IP anomalies considering the background geology. The shallow bedrock indicated a low risk to groundwater contamination because of its competent nature from its geology, and characteristic high resistivity values (≥1000 Ohm-m). However, the steep nature of the landfill terrain due to its location at the foot of a vertical slope favours the rapid migration of the contaminants into the immediate vicinity of the landfill. The construction of containment structures such as waste cells will help in enhancing effective waste management practices in the landfill.

Highlights

Land lls are common feature of the environment, especially in urban and highly populated cities where they have become a predominant means of waste disposal
Increasing population and urbanization have led to the use of land in the vicinity of land lls either as public or residential. is expose human and animals to environmental hazards such as percolation of polluted leachate into the shallow aquifers that serves as a major source of water supply in developing countries such as Nigeria, Botswana, Ghana, and South Africa [3,4,5,6]
Conductivity (EC) logging, and seismic surveys, for delineating the occurrence and movement of leachate and for facilitating decision making regarding the location of monitoring wells have been used over the years [10]. is study focussed on the use of electrical geophysical method involving the 2D electrical resistivity and induced polarization (IP) technique to map possible leachate distribution and migration processes from the land ll site in Alice Town, Eastern Cape Province of South Africa

Summary

Introduction

Land lls are common feature of the environment, especially in urban and highly populated cities where they have become a predominant means of waste disposal. 1: Map of the Eastern Cape Province showing the study area. Is study focussed on the use of electrical geophysical method involving the 2D electrical resistivity and induced polarization (IP) technique to map possible leachate distribution and migration processes from the land ll site in Alice Town, Eastern Cape Province of South Africa. E study area is located in the Eastern Cape Province (Figure 1), which lies on the south eastern seaboard of South Africa. It is estimated that only 8% of land lls in the Eastern Cape Province complied with Department of Water A airs and Forestry (DWAF) minimum requirements, 54% could potentially comply and 38% are currently unacceptable [18]. Measured resistivity values were plotted against the current electrode separation (AB/2) and the results obtained were interpreted through visual inspection and computer inversion

Results

Discussion

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