Alemayehu, Esayas (Professor)Tshepho, Josephine2020-09-182023-11-092020-09-182023-11-092020-07-07http://10.90.10.223:4000/handle/123456789/22364One of the ways to protect public health and environment by the elimination of waterborne diseases and pathogens is water undergoing treatment before consumption, making this process very important. Hence there is a need for regular monitoring of the performance of water treatment plants as this will ensure public water supply quality control management, consequently ensuring consumers’ safety. Performance evaluation of a water treatment plant (WTP) is a process to measure the functioning efficiencies based on some established performance indicators such as turbidity, color, suspended impurities, E-coli, Total Dissolve Solid, Residual Chlorine. Therefore, the overall objective of this study was to evaluate the performance of Gaborone and Mmamashia treatment plants (Botswana) with regard to their ability to produce quality water and control pathogens. The water parameters, pH, Total Coliform, E-coli, turbidity and conductivity, were analyzed based on the years 2019 and 2020 Autumn season. Secondary data was obtained for the year 2019 while sampling and standard laboratory tests and analysis were done for the year 2020. One hundred and twenty samples were collected from each water treatment plant (WTP) for five weeks. Samples were taken from raw water entering the water treatment plants and after disinfection stage. The weighted arithmetic water quality index method was used to classify the quality of treated water. The log removal value and turbidity removal efficiency were determined using the respective formulas. Correlation statistical technique was carried out to find out if there was any direct or indirect relationship between the parameters. The results from the study showed that, all the water parameters analyzed after disinfection stage for both treatment plants fall within the permissible limit for World Health Organization and Botswana bureau of standards. The water quality index for both plants was below 50 hence the water quality was classified as excellent. Overall, log removal value for Mmamashia, for the years 2019 and 2020 were, 1.96 and 1.3 respectively, for Gaborone, the values obtained were 2.24 and 1.52. Overall turbidity removal efficiency for Mmamashia for the years 2019 and 2020 was, 98.34% and 83.04% respectively while for Gaborone, 99.31% and 96.83% values were obtained for the years 2019 and 2020. There was significant correlation between parameters for both treatment plants. The treatment plants were found to be doing well with respect to providing the public with safe water and there was no significant difference between the v treatment plants except for the quality of raw water each is receiving. This study, therefore, acts as a baseline for further research regarding the efficiency of the Gaborone and Mmamashia treatment plants.enGaboroneMmamashiaWater Treatment PlantWater Quality ParametersPerformance EvaluationTurbidity Removal EfficiencyThesis