EVALUATION OF DRINKING WATER QUALITY IN TERMS OF WATER QUALITY INDEX FOR FARIDPUR SADAR UPAZILA

The quality of drinking water plays a vital role in public health. In this study, the quality of drinking water at Faridpr Sadar Upazila was evaluated by the water quality index (WQI). As the local people mainly rely on groundwater as a source of drinking water, eight groundwater stations were selected for sample collection within the locality. The water quality index was assessed using two widely used methods: Canadian Council of Ministers of the Environment (CCME) WQI and Weighted Arithmetic Index Method (WAM). To assess WQI, nine input parameters were used; which are pH, turbidity, nitrate, temperature, dissolved oxygen (DO), total dissolved solids (TDS), iron, arsenic and biochemical oxygen demand (BOD5). According to the CCME WQI method, WQI varied from 65.1 to 82.1 and by the weighted arithmetic index method, the value of WQI varied between 20.4 and 151.1. The study revealed that, by both methods, WQI indicates that water of the maximum stations is not up to the mark and a sample of only one station (S3 sample from Faridpur Chowdhury Bari) was found to be excellent or good for drinking purpose. Besides the above findings, BOD5 was the parameter, which was found to cross the acceptable limit for all the stations. Moreover, while comparing the result of WQI by both methods, it was found when low acceptance ranged parameters (i.e. Arsenic, BOD, Iron, etc.) dominate, water is categorized in a wider range in the WAM WQI method than by CCME WQI method. This because weights are assigned to each parameter according to their acceptance range. However, it is expected that this paper may assist in raising awareness among policymakers and local people on the quality of the drinking water of the study are