Evaluation of Water Quality along the Bank of River Hoogly (Kolkata Metropolitan Area) Using the Physico-Chemical Parameter and Water Quality Index

Abstract

The Hoogly River in the Gangetic delta plays a fundamental role in local society, as a source of irrigation and drinking water and as a sink for urban waste water. In order to analyze spatial and temporal variability of the overall water quality of the watershed Water Quality Index (WQI) by aggregative and multiplicative methods were calculated from eight physico-chemical parameter taking water samples from six different locations in and around Kolkata throughout a year during both high tide and low tide conditions. Seasonally, it was found that water quality decreases from winter to summer but it improves during monsoon. Depending on the location, different parameters like BOD, COD, DO, Conductivity etc. were responsible for the episodic fluctuation of water quality. The study reveals that the tributaries like Damodar, Roopnaryan and urban waste water discharge jointly contribute to the appreciable content of toxic metal in the bottom sediment of Hoogly River.