Lake water quality assessment and water quality indexing

Abstract

Assessment of water quality can be defined as the analysis of physical, chemical and biological characteristics of water. The present work was carried out to assess a water quality index (WQI) of the Victoria Lake, Rabindra Sarobar Lake and Saheb Bandh Lake, an important wetland which has been under pressure due to the increasing anthropogenic activities. The values of physical , chemical and biological parameters like temperature (Temp), potential hydrogen (pH), electrical conductivity (EC), turbidity (T), dissolved oxygen (DO), total hardness (TH), calcium (Ca), chloride (Cl), fluoride (F), sulphate (SO4 2-), magnesium (Mg), phosphate , sodium (Na), potassium (K), nitrite (NO2 -), nitrate (NO3 -), total dissolved solids (TDS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD),total coliforms and fecal coliform etc01.01.2013 to 30.03.2022 taken from West Bengal Pollution Control Board. The values obtained were compared with the guidelines for bathing purpose suggested by the World Health Organization, Gazette of India: Extraordinary [Part-II, Sec-3 (i)]and Bureau of Indian Standard. Four parameters like PH, DO, BOD and Fecal Coliform were selected to derive the WQI for the estimation of water potential for three lakes. An assigned weight was selected to each parameter range from 1 to 6 based on its importance. The WQI values for 13 sampling out of 108 sampling in Saheb Bandh Lake,13 sampling out of 107 sampling in Rabindra Sarobar Lake and 5 sampling out of 31 sampling in Victoria Lake are not suitable for bathing, including both human and animals, even though the people living inside the Lake are using it for bathing purposes. The implementation of WQI is necessary for proper management of the Victoria Lake, Rabindra Sarobar Lake and Saheb Bandh Lake and it will also help in assessment and periodic monitoring of water quality for minimizes the water pollution level in spite of increasing anthropogenic activity and urbanization within the sensitive area. Key Words: Victoria Lake, Rabindra Sarobar Lake, Saheb Bandh Lake, Water Quality, Water Quality Index