Sanitation and groundwater (Cameroon)

The study presents the current state of groundwater vulnerability in the town of Ebolowa in Cameroon. It was based on the DRASTIC method. The results enabled three sources of groundwater pollution to be defined: pollution by infiltration of contaminated water of domestic and urban origin, pollution by infiltration of contaminated surface water of industrial origin, and pollution of agricultural origin. The vulnerability index was then determined; two classes of vulnerability are present in the town, with DRASTIC indices ranging from average (133) to high(181) according to the ALLER and ENGEL classifications. It appears that the vulnerability maps obtained are valid insofar as, on the ground, there are anthropogenic causes that make groundwater more vulnerable. Observation of the immediate environment of the wells showed that most of the wells in Ebolowa are traditional and unprotected, with water depths of between 12 and 0.8 m. The sanitation facilities identified during the surveys in 164 households (46% non-return latrines, 37% septic tanks, 9% barrel latrines, 7% manual flush toilets and 1% VIP latrines) do not always comply with construction standards, and where the water table is shallow, the risk of pollution is sufficiently high. Households cite lack of space on their plots as the reason for locating wells close to sanitation facilities. The water from two wells was analyzed at the laboratory and the indicator germs for faecal contamination were determined and the results showed that the samples were unsatisfactory in terms of the germs tested for. A faecal contamination index was calculated, with values of 5 for well 1 and 7 for well 2, indicating that the water studied was moderately and heavily polluted.