Hydrochemistry and an appraisal of surface water and groundwater quality for domestic and irrigation use in parts of Southern Benue Trough, Nigeria

This research attempts to assess the hydrochemistry of major ions, the quality of surface and subsurface water, as well as its suitability for domestic and agricultural uses, in parts of the Southern Benue Trough. A total of thirty water samples were collected and analyzed in the laboratory using standard practices. Results revealed that the concentration of major cations for both surface and groundwater is in the order: Na⁺ > Ca²⁺ > Mg²⁺ > K⁺, while major anionic constituents are, respectively, present in the order: Cl^- > HCO₃ ^- > CO₃ ^2- > NO₃ ^- > SO₄ ^2- and HCO₃ ^- > CI^- > CO₃ ^2- > NO₃ ^- > SO₄ ^2- for surface and groundwater. The water quality index (WQI) model revealed that 100% of the surface water is of good quality for domestic and other uses, while 29.17% and 70.83% of the groundwater are of excellent and good quality, respectively. Three water types were identified, namely Na-Cl, Ca-Mg-HCO₃, and Na-HCO₃. Lastly agricultural indices (total hardness, TH, percent sodium, %Na, sodium absorption ratio, SAR, residual sodium carbonate, RSC, permeability index, PI and magnesium hazard, MH) computed along with various plots, revealed that the analyzed surface and subsurface water are suitable for irrigation purposes. The application of plots, tables, and models based on the major ionic constituents, gives fast and effective visualization of the quality and chemistry of surface water and groundwater.