Lathamani R , M. R. Janardhana , S. Suresha
Groundwater is a natural resource for drinking water. Assessment of ground water quality status in Mysore city by using water quality index (WQI) method was carried out. From the sampling locations spread throughout city, 53 groundwater samples were collected both in pre- and post-monsoon seasons. WQI has been determined by subjecting the samples to comprehensive physicochemical analysis. For calculating the WQI, the following 13 parameters have been considered: pH, EC, TH, TDS, Ca2+, Mg2+, Na+, K+, CO3 2-, HCO3 -, SO4 2-, Cl- and NO3 -. The WQI for the groundwater samples ranges from 42.61 to 109.51 and from 39.82 to 166.19 for PRM and POM seasons respectively. The results of some of the water samples show values over the permissible limits of WHO and BIS standards for drinking waters for parameters such as calcium and magnesium cations, nitrate and sulphate anions, and also in the global parameters: salinity and TDS. The elevated value of WQI has been found to be mainly from the higher values of nitrate and hardness in the groundwater. The analysis reveals that the groundwater of the area needs some degree of treatment before consumption