Dessalegn Geleta Ebsa* and Wakjira Takala Dibaba
Disinfection By-Products (DBPs) have heterogeneous structures, which are suspected carcinogens as a result of reactions between Natural Organic Matter and oxidants/disinfectants such as chlorine. Because of variability in DBPs characteristics, eliminate completely from drinking water by single technique is impossible and it have been considered as toxic contaminants of water. Disinfection By-product is another problem available in water supply treatment in the distribution system. The objective of this study was evaluating the performance of Jimma town water distribution networks of water treatment plant. Hence, the study was addressed, efficiency of conventional water treatment plant unit, chlorination and disinfection and disinfection by-product. To evaluate the water treatment plant simulation WatPro v4, tool was applied for disinfection and treatment plant performance. As per the discussion held with the Jimma water supply and sewerage authority and field visit, the major factors of water loss were identified. As per the calculation result, the treatment plant efficiency of the town was estimated as 69.75%. In case of giardia and viruses reduction (22.6% and 75.34%), that was the results obtained from the treatment plant simulation did not obey the surface water treatment rule. Despite its small amount, disinfection by products has been found in the town’s water treatment plant. As per the calculation obtained; the contact time of the water system did not meet the contact time requirement because 0.476<1. In general, the current water distribution network and treatment plant of Jimma town were in poor performance and were not conducted adequate water to the various demand categories of the town. Hence, it is important to rehabilitate and the treatment plant of the town in order to fulfill the required need.