Spatiotemporal Portrait of the Quality of Water Supplied by REGIDESO/Butembo, Democratic Republic of the Congo

Abstract

Access to drinking water is still a daily struggle for millions of people living mainly in developing countries. As a matter of concern, the main problem with regard to the use of safe drinking water mainly concerns its physicochemical and microbiological quality. This study has been carried out with the aim of contributing to a better understanding of the spatiotemporal variability of the quality of the water supplied by two drinking water distribution system of the REGIDESO in the city of Butembo (DR Congo). Its target is to have a view on its evolution in a period of six months even after the combination of its two networks. The methodology hinges around the microbiological and physicochemical analysis of the waters of eight sites identified on these networks. It results from this study that almost the treated water samples presented values, which did not comply with the WHO quality guidelines for many microbiological physicochemical parameters. Thus, the means of bio-indicators numbers are as following: Germs revivable at 37 oC (29.36 > 10 CFU/ml), total coliforms (21.89 > 0 CFU/ml), thermo-tolerant coliforms (3.53 > 0 CFU/ml,) Escherichia coli (1.25 > 0 CFU/ml) and enterococci (0.14 > 0 CFU/ml) while, for the Salmonella and Shigella (0.3056 > 0 CFU/ml). In addition, only the 3/5 (e.g. 60%) of the mean numbers of Enterococci and numbers of Salmonella & Shigella of the treated water samples fit WHO norms. Moreover, seven physicochemical parameters presented general averages far from the admissible maximal values (AMV). There are Ammonia (1.67 > 0.5 mg/L), Ammonium (0.32 > 0.3 mg /L), Iron (0.36 > 0.3 mg/l), Nitrate (55.94 > 50 mg /L), pH (6.03 < 6.5 - 8.5), Water Temperature (21.12 > 8oC - 15oC) and Turbidity (6.57 > 5 N.T.U). This reveals a high exposure of the population of Butembo to the health risk related to the use (consumption) of this water.