Monitoring of the Physicochemical and Microbiological Quality of Water Produced and Distributed by La Congolaise Des Eaux (LCDE) in Brazzaville

Water is an essential element for all living beings and therefore deserves special attention to maintain its quality. The objective of this work is to monitor the physicochemical and microbiological parameters of the water produced and distributed by La Congolaise Des Eaux (LCDE) of Brazzaville in order to evaluate the risk on the health of consumers. Ninety (90) and eighty-five (85) samples were taken respectively in the southern and northern areas of the city of Brazzaville. These different samples were analyzed using physicochemical and microbiological methods.

The results obtained show that these waters have high temperature values, ranging from 27.88 and 28.10°C in the South and North zones compared to the WHO guideline value (25°C) and have a moderately acidic pH (6 ,20-7.00) in both areas.

The turbidity of the water is more pronounced in the southern zone (6.83 NTU) and is reflected in the absence of residual chlorine in the maximum number of sampling points with low mineralization. From a microbiological point of view, these waters show contamination with total germs, total coliforms and fecal coliforms. This contamination is more pronounced in the southern zone than in the northern zone. Thus, the factorial analysis shows contamination by total germs and indicator germs of fecal contamination (total coliforms and fecal coliforms) and reflects the lack of residual chlorine at the consumer's tap.

In view of the results obtained, this study shows that the ageing of the installations and the dilapidated state of the pipes of the LCDE have a negative impact on the quality of the water distributed, which constitutes a high health risk for the consumers.