Mapping Contaminant Plume at a Landfill in a Crystalline Basement Terrain in Ouagadougou, Burkina Faso, Using Self-Potential Geophysical Technique

Abdoul Barry,Samuel Nakolendousse,Abdessamad Tiouiouine,Ismail Mohsine,Meryem Jabrane,Hajar Lazar,Suzanne Yameogo,Meryem Ayach,Ahlam Filki,Meryem Touzani

doi:10.3390/w13091212

Abdoul Barry, Samuel Nakolendousse + Show 8 more

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https://doi.org/10.3390/w13091212

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Abstract

The delineation of pollution plumes generated by household waste landfills is not easy, particularly in the case of discontinuous or intricately extending water tables, such as those developed in a fractured crystalline bedrock context. In Ouagadougou (Burkina Faso), there are many uncontrolled landfills throughout the urban area. The water table, generally located between 3 and 10 m deep, is likely to be contaminated by the leachate from these landfills. More than 1000 measurements of spontaneous potential (self-potential), referenced by GPS, have been carried out on a landfill and its immediate surroundings to the south of the urban area. The geostatistical processing by analysis of variograms and correlograms highlights an adapted prospecting technique and reliable cartography. The response seems to be mainly due to the electrochemical component with hot spots within the landfill and a plume heading towards the North-East. The distribution of the spontaneous potential seems to be controlled, not by the topography of the site, but by the fracturing of the mother rock of dominant direction 15° N, and by the mother rock/saprolite contact. Thus, the plume does not flow to the market gardening just below the landfill but rather to a residential area where monitoring of the quality of the borehole water is required.

Highlights

For many countries, the Sahelian countries, groundwater is a large proportion of the water resource, whether it is used to feed people or to irrigate food crops [1].Paradoxically, it is in densely populated areas, and where it is prized, that this resource is most at risk, in terms of quantity, but above all in terms of quality.Household waste dumps, when they are not made up of watertight caissons, are often the source of pollution, as the fermentation of the waste generates leachates that flow down to the water table
The correlation coefficient zeroes for a value of the order of 400 m. All these results indicate that the density of measurements allows extrapolation between transects and allows fairly reliable mapping of the spontaneous potential over the prospected area
150 to m the intervals relevant althoughand geostatistical the potential, high give resistivity ofresults, the materials, the depth of analysis informed that less dense measurements but slightly less widely both the water table and the probable pollution plume

Summary

Introduction

The Sahelian countries, groundwater is a large proportion of the water resource, whether it is used to feed people or to irrigate food crops [1].Paradoxically, it is in densely populated areas, and where it is prized, that this resource is most at risk, in terms of quantity, but above all in terms of quality.Household waste dumps, when they are not made up of watertight caissons, are often the source of pollution, as the fermentation of the waste generates leachates that flow down to the water table. The Sahelian countries, groundwater is a large proportion of the water resource, whether it is used to feed people or to irrigate food crops [1]. It is in densely populated areas, and where it is prized, that this resource is most at risk, in terms of quantity, but above all in terms of quality. The consequence is a pollution of the aquifer with heavy metals, dissolved organic matter, nitrogenous forms, phosphorus and various micro-organisms, especially pathogens In this context, the use of polluted water, for the irrigation of green vegetables, for bathing or even for drinking, is a major health issue. These issues have been the subject of numerous studies in many countries

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