Water quality of few springs in outer Himalayas – A study on the groundwater–bedrock interactions and hydrochemical evolution

Abstract

Springs in the Kandela valley in a part of outer Himalayas, India were sampled and analyzed for their major ion chemistry in order to assess their water quality, possible origins and hydrochemical evolution of the waters. Analyses of springs water samples show that the concentrations of Ca2+ exceed that of Mg2+ in all springs; the concentrations of Na+ are next to Mg2+ and are higher than that of K+; HCO3− and SO42− are most dominant among anions compared to Cl− and NO3−. The spring waters are categorized into two end-member hydrochemical facies: (1) pH-mildly alkaline, Ca–Mg–HCO3 water with low to moderate EC; (2) mildly alkaline, Ca–Mg–HCO3–SO4 water with moderate EC. The facies 1 water occur mainly due to easy dissolution of carbonate minerals. This facies may occur during recharge which results in low ionic concentration in shallow zone in regional carbonate aquifer. The facies 2 waters are chemically distinct from waters in the valley. PHREEQC geochemical modeling show that all water are supersaturated with respect to carbonate mineral but are undersaturated with respect to evaporite and precipitation of carbonate, dissolution of evaporite and ion exchange are important process during the groundwater–bed rock interactions and hydrochemical evolution. Groundwater generally occurs under water table condition and is fit for drinking and irrigation purposes in study area.