Fecal Coliform Bactria Extent and Distribution Assessment in Lake Hawassa Watershed

Abstract

Usually, the life of human beings is determined by how much they get adequate and safe water. Despite its importance, however, water may have adverse effect if the quality is low. Contaminated water mostly leads to exposure of bacterial pathogens such as Salmonella, Shigella, and Vibrio that can cause several types of infections and diseases to those who utilize it. In order to keep the public safety and avoid health risks from pathogens carried by water, gastrointestinal pathogens for instance, there are different bacteriological tests fundamental indicating the presence of specific bacteria thereby assessing the hygienic quality. Hence, this study was initiated with the aim of determining the extent and distribution these water quality indicators exist in Lake Hawassa Watershed, thereby assess the level of risk on public health and ecosystem of the watershed. In order to assess fecal coliform bacteria the present study were considered two major sites; surface and tap water. The presences of fecal coliform bacteria in the collected samples were analyzed in the laboratory by implementing membrane filter technique. All samples were found to be contaminated with faecal coliform and the counts were higher than the maximum microbial contaminant level established by World Health Organization. More than 5 FC/100 ml were recorded from communal borehole water source mostly located in rural parts of the watershed. While samples from public tap water from Hawassa city shows less than 4 FC/100 ml compared to boreholes. Similarly sample analysis from river indicated that most of the samples contained FCB. The maximum FCB was recorded in the upper part of the watershed at Bussa and Shenkora River where the rural population density is much higher. Whereas, the minimum FCB is recorded at Tikur Wuha, which is the only perennial river recharging lake Hawassa. On average, the number of FCB from the sampled rivers was 4.6 per sample whereas 3.3 from tap water. As compared to the tap water, the number of FCB obtained from the sampled rivers was high but not significantly different. Hence, an indication of improper and low water treatment practices and/or lack of well protected water supply mechanisms therefore, a need for an immediate action.

Key words: Water quality; Fecal Coliform; Spatial distribution; temporal distribution