Assessment of Water Quality and Evaluation of Water Quality Index of Loktak Lake

Rapid population growth, urbanization and modernization are posing sewage disposal and contamination issues in surface waters such as lakes and rivers. Lakes frequently have significant pollution levels in comparison to the surrounding landscapes and environment. The primary goal of this work is to evaluate the physicochemical water quality of Loktak Lake, Manipur, India. Physicochemical characteristics such as water temperature, pH, total dissolved solids (TDS), electrical conductivity (EC), turbidity, hardness, alkalinity, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), chloride (Cl), magnesium (Mg), sodium (Na), phosphate (PO43−), nitrate (NO3) and nitrite (NO2) were measured during August 2022 to April 2023. The results for different location of the lake and different season, i.e. post-monsoon, winter and pre-monsoon, were compared to the standard values specified by the Bureau of Indian Standards (BIS), and a subset of the findings was chosen for the Water Quality Index (WQI) analysis. The WQI value ranges from 72 to 144, indicating that several points of the Loktak Lake is not fit for drinking.