Assessment of Heavy Metals Toxicity and Ecological Impact on Surface Water Quality Using HPI in Ganga River

Present study is to reveal the seasonal variations in the river water quality by heavy metals contamination. To get the extent of heavy metals contamination, water samples was collected from 12 different locations along the course of the River Ganga and its tributaries in winter, summer, monsoon and post-monsoon seasons. The concentrations of trace metals such as Zn, Pb, Mn, Fe, Cu, Si, Al, Ni, Cd, Mg, and Co were determined using atomic absorption spectrophotometer (AAS). Most of the samples were found within the limit of standards i.e. Indian drinking water standard (IS: 10500). The data collected by on-site and lab analysis was used to calculate the heavy metal pollution index (HPI) of river water. During the study Ni showed the highest positive correlation value with Al and the highly negative was recorded with Mg. The values of HPI were 33.34, 26.12, 27.88 and 26.86 in respective seasons. These values are below the critical index limit (100) in all the seasons because of the sufficient flow in River System. So, the present study shows that the water quality of River Ganga is unpolluted with respect to heavy metals.