Hydrochemical investigations and correlation analysis of groundwater quality.

A study was conducted to evaluate the water quality of Sambhar lake city (India) and its adjoining areas. Groundwater samples from hand pumps and tube wells of fifteen sampling stations were analyzed during post-monsoon session with the help of standard methods of APHA. The analytical results showed higher concentrations of TDS, EC, Sodium, Nitrate, Sulphate and Fluoride, which indicate signs of deterioration but values of pH, Calcium, Magnesium, TH and Carbonate were found within permissible limits as per the WHO standards. From correlation analysis it was observed that very strong correlations exist between Na+ and Cl- (0.99) as well as EC and Cl-. From Hill-piper trilinear diagram it is observed that the majority of groundwater from sampling stations was sodium-potassium-chloride-sulphate type water. The values of sodium absorption ratio and EC of groundwater were plotted in the US salinity laboratory diagram of irrigation water. Only one sample was found to fall in C3S1 quality with high salinity hazard and low sodium hazard. Another samples were found to fall in high salinity hazard and high sodium hazard. Chemical analysis of groundwater showed that mean concentration of cation is in order sodium > magnesium > calcium > potassium while for the anion it is chloride > bicarbonate > nitrate > sulphate.