Hydrogeochemical assessment of groundwater in Moro area, Kwara State, Nigeria

Detailed study of chemical analysis results of several groundwater samples (UNICEF-Assisted Water Project, Kwara state, Nigeria) were carried out in an attempt to assess the quality and usability of groundwater in the Moro area. Chemical analysis results indicate higher concentrations of Ca super(2+), Mg super(2+), and HCO sub(3) super(-) as compared to Na super(+), K super(+), Cl super(-), and SO sub(4) super(2-). With exception of few locations where Fe is relatively highers, the concentrations of these ions together with other water quality parameters are all within permissible limits of the domestic and agricultural standards. On the basis of the analytical results, groundwaters in the study area are largely characterized as Ca-(Mg)-HCO sub(3) type reflecting (possibly) young facies with limited migratory history. The occurrence of Ca-(Mg)-Na-HCO sub(3) water type in certain areas is attributed to cation exchange processes. In addition, the observed scattered relationship between the TDS and the thickness of weathered horizons in the boreholes indicates the contribution of precipitation (recharge) to the ionic inputs in the groundwaters in addition to the weathering and dissolution processes.