The ion exchange between groundwater and its aquatic material during residence time can be estimated by using chloro-alkaline indices (CAI) (Schoeller, 1965, 1967). Generally, the CAI values positive or negative. When there is an exchange between Ca and Mg in the groundwater with Na and K in the aquifer material, indices (CAI values) are negative, and if there is a reverse ion exchange, then indices (CAI values) will be positive which means ion exchange between Na and K in the groundwater with Ca and Mg in the aquifer material (Schoeller, 1965, 1967).