Variations in bacteriological and physicochemical water quality characteristics of Asata River, Enugu, Nigeria

Background and Objective: Globally, river water remains an important source of water for drinking, domestic and other uses. This study aimed to assess the bacteriological and physicochemical properties of Asata River water. Materials and Methods: A total of 72 water samples were collected, over 12 months (September, 2017 to August, 2018), from six different sites along the river course, following standard methods. The physicochemical properties were determined in situ using appropriate measuring instruments. Total coliform counts (TCC) and Escherichia coli counts (EC) were determined using Chromocult Coliform Agar following the membrane filtration technique. Student’s t-test statistic was used to compare the variations in mean values obtained during the rainy and dry seasons. Results: Temperature, total dissolved solids, pH and electrical conductivity had mean values ranging from 24.8-26.8°C, 10.8-20.1 mg L–1, 4.0-7.1 and 15.8-29.5 μS cm–1, respectively. Mean values of bacteriological parameters ranged from 5.0×101-5.9×106 (TCC) and 1.0×101-4.6×106 (E. coli counts). Bacterial counts in the rainy season were significantly higher (p< 0.05) than counts during the dry season. A significant correlation existed between EC and other water quality parameters, temperature, pH, TDS, E. coli and TCC. Bacteriological properties were high and beyond the acceptable standard limits. Conclusion: Asata River water quality is poor and may constitute a serious public health risk if used without treatment. Adequate provision and use of suitable sanitary infrastructure will help protect this water source from further faecal contamination