Microbiological Quality Assessment of Well and Borehole Water for Domestic Consumption in Parakou Municipality, Benin

Abstract

Safe drinking water remains a major public health challenge in many developing settings. This study assessed the microbiological quality of well and borehole water intended for consumption in the municipality of Parakou, Benin. A total of 189 samples, comprising 135 well-water samples and 54 borehole-water samples, were analysed using culture-based methods described by Rodier et al. (2009). Total coliforms, faecal coliforms, enterococci, Escherichia coli, and presumptive Vibrio spp were investigated. Total and faecal coliforms were detected in 94.17% of the samples, E. coli in 91.00%, and presumptive V. cholerae in 64.55%; enterococci were not detected. Well water had a significantly higher Vibrio spp load than borehole water (p = 0.001), whereas differences between the two sources were not statistically significant for the other microbial indicators. Based on E. coli detection, 92.59% of well-water samples and 87.03% of borehole-water samples did not comply with the applied WHO microbiological criterion. Co-contamination by at least three microbial groups was the predominant pattern in both source types, indicating widespread exposure to multiple indicators of faecal and environmental contamination. These findings show that both wells and boreholes used by households in Parakou are vulnerable to microbiological contamination. Regular microbiological surveillance, improved protection of water points, better sanitation around sources, treatment of water before consumption, and risk communication are warranted. Because identification was culture-based, the detection of Vibrio spp should be interpreted as presumptive pending confirmatory testing.