Groundwater Quality of Tahoua Region and Environs of the Iullemmeden Basin.

Abstract

The quality of groundwater in parts of Tahoua region, in the Iullemmeden Basin, around the border areas of SW Niger Republic and NW Nigeria has been evaluated. Results of the geochemical analysis of the groundwater of the Lower Zone aquifer show that the Continental Intercalaire has weakly mineralized water (conductivity <130 μS/cm) and the water can be used for all purposes. Also in the Lower Zone, the Alanbanya aquifer water is hard to very hard, of Ca-Mg-SO4 type, with high nitrate content 0 - 482 mg/l. This may call for a bacteriological analysis, since this concentration is far from the WHO limit. In the Upper Zone aquifers comprising the Upper Tertiary continental (sands and sandstones) sediments of the Ader Doutchi (Continental Terminal) and the overlying Quaternary Formations, the conductivity is also high indicating its strong mineralization. The concentration of nitrate is up to 416 mg/l, the water being relatively hard (TDS up to 3140 mg/l), requiring that it be used carefully for domestic purposes.