Impacts of mining on the Izégouande water table in Niger

In the Tim Mersoï basin in northern Niger uranium deposits have been exploited for five decades by two mining companies. Increased mining activity coupled with population growth is placing heavy demands on the groundwater resources of the Permian Izégouande aquifer. Over the past decade this aquifer has contributed almost 70% of the mining area's drinking water supply. The aim of this work is to demonstrate the impact of mining activities on the hydrodynamic functioning of the Izégouande aquifer and on its vulnerability to pollution. To achieve this objective an interdisciplinary methodological approach was implemented integrating the analysis of isobath and isopaque curves and the study of hydrodynamic and hydrochemical parameters. Several diagrams (Chadha Gibbs Schöeller Berkaloff etc.) were drawn up along with a pollution vulnerability map. PCAs Binary Ion Relationships and the calculation of saturation and cation base exchange indices were used to determine the origin of groundwater mineralization.