Quality Control of Tap Water and Factors Determining Bacterial Contamination of Households’ Stored Drinking Water in the Town of Aboisso (Côte d’Ivoire)

Abstract

Piped water must inspire consumer confidence in health and organoleptic terms. In the event of a food poisoning, consumers who have a poor perception of its quality may incriminate it, without taking into consideration that the fact of passing it through a drinking water storage container before consuming it can also cause contamination. The present study carried out in the town of Aboisso aimed to assess the role of water storage in the deterioration of microbiological quality of drinking water, and to identify the predictive factors of the presence of bacteria in stored water. To do this, physicochemical parameters (temperature, pH, conductivity, turbidity and free chlorine) and microbiological parameters (total coliforms, thermotolerant coliforms and <i>E. coli</i>) were measured on water samples taken from taps and storage containers in 94 households. The storage conditions of drinking water were also the subject of a brief household survey. The identification of predictive factors for the presence of total coliforms and <i>E. coli</i> in stored water was done using bivariate analysis and multivariate analysis by binary logistic regression through two models. The first model included the use of a transport container and the storage conditions as independent variables. The second included besides that the values of turbidity and free chlorine. As results, the waters were weakly mineralized and acidic. Free chlorine levels, temperature values, and bacterial loads in tap water were significantly (p < 0.05) higher than those in stored water. While 13.83% of samples taken at the taps were contaminated with total coliforms and 1.06% with <i>E. coli</i>, 50% and 18.09% of those taken in containers were contaminated with total coliforms and <i>E. coli</i>, respectively. In the first model, only the storage duration and the method used to draw water from storage container were statistically associated with the presence of total coliforms while no variable was statistically associated with the presence of <i>E. coli</i>. In the second model, the drawing method and the free chlorine level were significantly associated with the presence of total coliforms while only the free chlorine level was associated with <i>E. coli</i>. These results motivate the need to raise awareness and train populations in drinking water hygiene.