Water Treatment Performance Evaluation Using Turbidy as a parameter

In most part of the world Water Supply sources are surface water requiring proper treatment to make the water fit for human consumption. Treatment plants are of various types based on quality of the raw water. The overall goal of any treatment plant is to produce water with acceptable quality standard. The most widely used quality standard is WHO guideline. Most treatment plants deteriorate and the efficiency drops due to various reasons. The efficiency has to be evaluated periodically to restore the capacity of the units. Sometimes efficiency of similar units may vary due to lots of reasons. Lagadadi and Gafarsa surface water treatment plants are located at east and west of Addis Ababa city and they are producing water for most area coverage of the city. Significant efficiency variation is observed when evaluated the units using turbidity removal as measuring parameter. In this study the effect of orifice size on floc carryover is observed as some of the orifices of the clarifiers were narrowed due to buildup of residuals through time.