Seasonal variation of drinking water quality in urban water bodies (UWBs) of Chittagong Metropolitan City, Bangladesh: implications of higher water quality index (WQI) for the urban environment

This is an empirical study on small urban water bodies in Chittagong Metropolitan City, Bangladesh. The ultimate objective was to explore the alternative source of fresh water supply for the city dwellers–the urban poor. To determine the level of drinking water, a suitability analysis was performed in conjunction with the construction and calculation of a Water Quality Index (WQI) for two distinct seasons: Rainy and Winter. The IBM Statistical Package for the Social Sciences (SPSS) Statistics version: 20 and CAP: version: 5.0.0.465 was used as a means to an end. The study reveals that water quality in sampled UWBs of CMC was found unsuitable (WQI value 237.11) for drinking in the Rainy season and very poor (WQI value 99.62) in the Winter. The eight (8) parameters that crossed the maximum permissible limit in the Rainy and Winter seasons include electrical conductivity (EC), biological oxygen demand (BOD), chemical oxygen demand (COD), turbidity and nitrate. The two biological parameters, i.e. total coliform (TC) and fecal coliform (FC) that stood alone in crossing the admissible limit, detected measured values 1100+ MPN- 100 mL−1 in Rainy and Winter seasons, against unit recommended value 50. Awareness building on water pollutants in both public and private sectors is required to improve public health service delivery.