Maladies transmises par l'air et l'eau

Abstrait

Microbial and Nutrient Contamination of Domestic Well in Urban-West Region, Zanzibar, Tanzania

Said A H Vuai

There is mushrooming of domestic wells in Zanzibar Town due to inadequate supply of tap water. The well water is used for domestic purposes including drinking. In many cases the wells are situated very close to pit latrines increasing the risk of contamination. This study attempted to assess the microbial and nutrients contamination in domestic well during dry and rainy season in the Urban-West Region of Unguja Island, Zanzibar. Nineteen domestic wells were sampled and analyzed for the microbial and nutrient quality of water. It was found that domestic wells were highly contaminated by both nutrients and coliform. The contamination was intensified during rainy season. Only 5% of the collected water samples met WHO and Tanzania standards for drinking water. This explains why in Zanzibar water borne diseases such as cholera and typhoid fever occur frequently. The major sources of contamination were found to be the pit latrines/ septic tanks. The degree of contamination was affected by the depth of a domestic well, and combination of number and location of a septic tanks surrounding a well at a particular location. It is recommended that frequent monitoring and treatment of the domestic wells could be a good solution to decrease the water born diseases.