Microbial quality of community drinking water supplies: A ten year (2004-2014) analyses in west Amhara, Ethiopia

Access to safe drinking water is an important public health and development issue at national, regional and local levels. Community drinking water supplies such as piped water, dug wells and springs are the predominant sources in rural villages and towns in Ethiopia. A retrospective analysis was conducted on microbial quality of community drinking water sources that had been processed from 2004-2014. Water samples were collected from 36 districts in west Amhara region. As per standard operational procedures, bacteriological analyses had been performed using multiple tube fermentation technique. A total of 1030 drinking water samples from (tap water n = 680), wells (n = 198), spring (n = 128) and reservoir (n = 24) were analyzed for microbial qualities. Overall, 29.0% (95% CI: 26.3-31.8%) and 44.7% (95% CI: 41.7-47.7%) of water samples had Escherichia coli and total coliforms (TC), respectively. Furthermore, 52.0%, 43.0%, and 20.2% of water samples from wells, spring and tap water were positive for E. coli. For faecal coliforms, 72.1% of drinking water supplies complied with World Health Organization and Ethiopian Standards. Tap water samples were 3.8 times less likely to be faecal contaminated than water samples from dug wells and spring water sources (OR = 3.8, 95% CI: 2.8-5.1, P = 0.001). This ten year trend analyses showed that microbial qualities of community drinking water supplies were not to the standards. This study reinforces the need to monitor microbial quality and chlorine treatment of community water supplies.