Evaluating Suitability of Groundwater for Drinking and Irrigation Purposes Using Conventional Techniques

This study aimed at evaluating the suitability of groundwater quality for drinking and irrigation purposes in a semi-arid region of Rajasthan by applying graphical analysis techniques of Piper, US Salinity Laboratory and Wilcox diagrams. A total of eight groundwater-quality parameter data for fifty-three sites were collected and analysed for a 16-year period (1992–2002, 2004–2008). The mean spatial concentration of Mg, Ca and HCO₃ exceeded the desirable limit prescribed for drinking water standards in some of the years. Overall, the groundwater quality was found satisfactory. The Piper diagram indicated that Ca–Mg–HCO₃ type groundwater predominates in the area, which is due to recharge from freshwater and presence of crystalline rocks. USSL diagrams classified most of the groundwater sites in C3-S1 class, which indicate ‘high-salinity’ and ‘lowsodium’ groundwater. The percentage of sodium computations showed that the groundwater in the area is presently suitable for irrigation, but it may reach up to contamination levels in the coming years.