
The hydrochemistry of groundwater of an estuarine aquifer was used to assess the quality of groundwater for determining its suitability for drinking and agricultural uses. The potability of ground water was estimated by considering the individual and/or paired ionic concentration, certain indices like alkali hazards (in terms of Sodium Adsorbed Ratio), % Na, Residual Sodium Carbonate, Permeability Index and hardness etc. Scientific interpretation of analytical data was done using hydrochemical computer program, WATCLAST, to classify ground water into different categories. With the help of Piper diagram hydrochemical facies like, Na-K−SO4-Cl, Ca-Mg–SO4-Cl and Ca-Mg–HCO3 were identified as dominating facies of the site. The factors responsible for their geochemical characterization were also attempted by using standard plot and it was found that the weathering was major factor controlling the groundwater chemistry of the study site although it is under heavy precipitation. After assessment of quality of groundwater, considering all the parameters and indices, the ground water of most of the locations were found to be suitable for irrigation and drinking purposes. However ground water of only a few locations was above standard prescribed levels by BIS (Bureau of Indian Standards) and WHO.