Bacterial contamination of urban water wells in the Nuwayri region of Beirut - Lebanon

Nine water wells serving nine different building residents in the Bourj Abi HaydarNuwayri region in Beirut (Lebanon) were tested for contamination with Gram negative bacteria by standard methods. The samples were obtained from the first outlet from the well that was available for the collection of the water by the users. Six of the wells grew numerous types of bacteria including coliforms and non-fermentative organisms. Two wells grew Salmonella and Shigella species respectively, while a third was recognized for the very big number of CFUs growing from the sample obtained. The three wells that did not grow organisms were obtained from a central tank in each building that was regularly chlorinated and from which the users collected their water supply, when needed. The results show that the substantial contamination obtained, prohibits the use of well-water in the region for any use, without proper treatment to avoid undesired medical consequences. Further studies and intervention of the public health authorities are needed, as the results of this study indicate that this problem seems to be of a bigger magnitude than presumed.