Abstract

This study aims to assess the quality of the water in the wells and boreholes at M'pody following an outbreak of diarrhoea in January 2020. The methodology consisted of carrying out four water sampling campaigns of the 72 identified wells and the single borehole over four seasons. Standard physico-chemical parameters were determined using electrochemical and spectrophotometric methods. Microbiological analysis was carried out using membrane filtration and mass incorporation techniques. Results showed that 29.6% of the parameters peaked during the long dry season, 25.9% during the long rainy season, 33.3 and 11.2% during the short dry season and short rainy season, respectively. Water was poorly mineralized, aggressive, and associated with a risk of methaemoglobinaemia in 24.30% of samples. These waters all contained germs indicative of faecal pollution, making them undrinkable. The non-potability of the analysed water was mainly linked to turbidity, pH, total iron levels, and nitrogen derivatives. It would therefore be advisable to treat water from wells in a domestic tank, and a simple chlorine treatment of the water castle would be appropriate before any distribution.

Key word: Drinking water, well, borehole, quality control, health risk.