HYDROGEOCHEMICAL ANALYSIS OF WATER IN THE AYANFURI AREA: IMPLICATIONS FOR HUMAN CONSUMPTION AND IRRIGATION

Abstract

The study of groundwater and surface water in the Ayanfuri area of the Central Region of Ghana has been carried out using hydrochemical analysis and geochemical modelling to determine its suitability for human consumption and irrigation purposes. A total of 77 samples were collected from community boreholes, observation boreholes, Tailing Storage Facility (TSF) boreholes, and streams and analyzed for geochemical parameters. Sodium is the dominant cation for all the sampling sites except for TSF boreholes which are calcium-dominated. Also, the dominant anion is bicarbonate for all sampling sites, except for streams that are sulphate-dominated. The hydrochemical facies in the sampling sites are Na-Mg-HCO3 (54.55%), Na-Mg-HCO3-Cl (23.08%), Na-Mg-HCO3 (22.22%), Na-Mg-HCO3-Cl (22.86%) representing community boreholes, observation boreholes, TSF borehole, and streams, respectively. Water-rock interaction, atmospheric precipitation patterns, ion exchange reactions, and breath dissolution/erosion of plagioclase feldspars serve as the mechanisms influencing the chemical composition of the various water sampling sites. The geochemical modelling reveals the signatures of calcite, dolomite, and gypsum as the main mineral phases. From the water quality guidelines of WHO and WQI classifications, the water is suitable for consumption purposes. Also, the results of the sodium adsorption ratio, sodium percentage, and magnesium hazard indicate that the water in the study area is suitable for irrigation purposes.