Evaluation of water quality index for River Sabarmati, Gujarat, India

An attempt has been made to develop water quality index (WQI), using six water quality parameters pH, dissolved oxygen, biochemical oxygen demand, electrical conductivity, nitrate nitrogen and total coliform measured at three different stations along the Sabarmati river basin from the year 2005 to 2008. Rating scale is developed based on the tolerance limits of inland waters and health point of view. Weighted arithmetic water quality index method was used to find WQI along the stretch of the river basin. It was observed from this study that the impact of human activity and sewage disposal in the river was severe on most of the parameters. The station located in highly urban area showed the worst water quality followed by the station located in moderately urban area and lastly station located in a moderately rural area. It was observed that the main cause of deterioration in water quality was due to the high anthropogenic activities, illegal discharge of sewage and industrial effluent, lack of proper sanitation, unprotected river sites and urban runoff.