Socio-economic influence of hydrogeology in regions adjoining coal bearing formation: Water policy in Anambra Basin

Abstract

Abstract The Coal Province lies within the central portion of Anambra Basin and along the axis of regional water resources catchment of Southeastern Nigeria. Although this area includes a prolific aquifer, the high cost of development and treatment of the groundwater degraded by AMD has created water scarcity problems against water policy initiatives. Social and economic impacts were investigated, even as policy measures for rehabilitation purposes through water resource management were highlighted. Several geoscientific methods were integrated for the investigations. Mean resistivity up to 30 Ω-m relatively at shallow depths indicated aquitards of Enugu/Mamu Formations, whereas the aquifer reflected resistivity ≤1,000 Ω-m at depths of ≥180 m across Ajali Sandstone. Alkaline-rich seepage flushed Fe-rich AMD at aquifer-aquitards interfaces adjoining the river catchment area. The AMD-induced oxidation process produced noxious Ca-Mg-Na-HCO3-SO4-Cl facie. These results were correlated with policy related questionnaires. Plans for water security were proposed, mainly to channel groundwater directly from the regional aquifer, or the chemically degraded seeped water from the fluvial system, into constructor water reservoir (treatment) columns prior to distribution to the town-water supply. Such water resource development is cost effective; and with management policies regulated by relevant decision-making agencies, sustainable supply is assured.