Assessment of ground water quality of metropolitan city Vadodara, Gujarat using water quality index

Abstract

Metropolitan city of Vadodara is 16th largest town in India (population wise) and the third in the state of Gujarat. The city witnessed a sudden spurt in industrial activity with the establishment of Gujarat Refinery, Indian Oil Corporation. It is the industrial nucleas of the Gujarat State. Vadodara and its surrounding areas are today humming with industrial activity. The mixture of different kind of untreated/partially treated/treated industrial waste is being discharged through a number of drains passing in and the city. Further, the surface runoff caused by rainfall and spills from loading of oil tankers also contribute to the ground water contamination. In the present investigation, assessment of the ground water quality of different drinking water sources in and around metropolitan city of Vadodara has been carried out by using water quality index. The water quality data of ground water of pre- and post-monsoon seasons of the year 2008 and 2009 has been used for the calculation of water quality Index. Fifteen parameters (TDS, HCO3, Cl, SO4, NO3, F, Ca, Mg, Na, K, Fe, Mn, Ni Cr and Cd) were used to calculate the water quality index and each of the 15 parameters (TDS, HCO3, Cl, SO4, NO3, F, Ca, Mg, Na, K, Fe, Mn, Ni Cr and Cd) has been assigned a weight (wi) according to its relative importance in the overall quality of water for drinking purposes. It was observed that quality was not observed to improve in about 50% of the locations after monsoon season during the year 2008 but during the year 2009, the quality of ground water was observed to improve in post-monsoon season in most of the samples. The groundwater of Limda, Harni, Nandesari and Makarpura was found to be ‘unsuitable for drinking purposes’.