Impact of Seasonal Flooding on the Bacteriological Quality of Drinking Well Water in Makurdi Metropolis, Benue State, Nigeria

Abstract

This study assessed the impact of flooding on the bacteriological quality of drinking wells in Makurdi Metropolis, Benue State, Nigeria. Twenty (20) well water samples were collected from flooded areas and nearby areas that were not affected by the flood, across Northbank, Wadata, Wurukum, Gyado Villa, and Achusa areas. The study employed standard microbiological methods to determine the total viable bacterial counts, total coliform counts, and bacterial species in the samples. The isolates were identified using colony morphology, Gram staining, and biochemical tests, while the data were analyzed using analysis of variance (ANOVA).Our findings showed numerically higher total coliform counts in most flooded well locations compared to their non-flooded counterparts, along with significant variation in coliform counts among sampling locations within each group (p<0.05), suggesting increased microbial contamination associated with flood events. Seven (7) bacterial genera were identified, including Shigella spp., Escherichia coli, Klebsiella spp., Bacillus spp., Proteus spp., Staphylococcus spp., and Streptococcus spp. Shigella species were the most prevalent isolates in the areas affected by the flood while Klebsiella and Streptococcus species were the most prevalent isolates in the non-flooded areas. The presence of fecal indicator bacteria (E. coli) and pathogenic microorganisms indicates that flooding greatly increases the risk of contamination of drinking wells, thereby raising the likelihood of waterborne disease transmission. The findings of this study show that flooding has adverse effects on the bacteriological quality of drinking well water in Makurdi Metropolis. Given the frequent occurrence of flooding in the study area, measures such as the construction and upgrading of wells with raised concrete aprons and properly fitted covers, improved sanitation infrastructure, routine microbiological monitoring of wells before, during, and after flood events, and community awareness of household water treatment methods should be implemented since the residents constantly depend on the well water for domestic use, including drinking. Additionally, the government should strengthen flood risk management strategies and ensure that the communities have access to alternative water sources during flood periods to reduce the incidence of waterborne diseases.