Chemical, physical, and microbiological characterstics of various sources of water in and around Addis Ababa

Abstract: Every month, from November 1996 to October 1997, water samples from 18 different sites were collected. The samples belong to the following categories: reservoirs that supply Addis Abeba's tap water (Lakes Gefersa and Legadadi) city taps, city swimming pools, Ambo Mineral Water, rain water, Akaki and Bulbula Rivers and Lake Aba Samuel. Four different physical variables (PH, Temperature, Total Dissolved Solids, and Conductivity) and concentration of 19 different cations, anions, and CO2 were determined. The results revealed no health risk except the high concentration of Cr3+, Cd2+, Fe3+, Pb2+, Mn4+ and Nitrate in Akaki and Bulbula Rivers samples. The water from these rivers is not consumed by city residents although they are used by rural communities to the east and southeast of Addis Abeba. Similarly, the two swimming pools included in this study had high TDS,HCO3- and fluoride content as well as slightly increased Cd2+, Pb2+ and Cu2+ levels. On the other hand, parasitological and bacteriological analyses revealed all sources were clean except Akaki, Bulbula and Aba Samuel. Infact these results suggest drinking waters of Addis Abeba are safe, while recreational waters of the city are acceptable for the purpose they serve. However, in view of polluted rivers flowing out of Addis Abeba and Lake Aba Samuel, methods of minimizing the health risks they pose are suggested. [Ethiop. J. Health Dev. 1999;13(3):239-246