HPI appraisal of concentrations of heavy metals in dynamic and static flow of Ganga River System

Ganga River system is a life support system to sustain the people of northeast region, India, by providing freshwater resource. In this study, the seasonal heavy metal concentrations of Ganga River system at Haridwar region (India) have been characterised for metal pollution. The collection of water samples was done from 10 different locations and analysed for various metal parameters (Zn, Pb, Mn, Fe, Cu, Si, Al, Ni, Cd, Mg and Co) using a standard laboratory procedures. The pollution level was assessed from the observed concentrations by using Heavy Metal Pollution Index (HPI) for nine heavy metals. The observed values of HPI were found lower than the Critical Pollution Index value of 100 (average value 78.62 and 81.18) during the study period. The concentration of Fe and Mg is exceeding the desirable limits of the World Health Organization, Bureau of Indian Standards and US Environmental Protection Agency in all water samples throughout the study period. The levels of all the metals were higher in the monsoon season and lower in the winter season. The Karl Pearson's correlation matrix was developed by using the mean values of all parameters and showed the light intensity positively correlated with biochemical oxygen demand (BOD) and sulphate which indicate good microbial activity. Dissolved oxygen and BOD is found negatively correlated. From this study, it is easy to understand the various harmful effects of metal pollution to irrigation water and health of local people.