Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2009.Includes bibliographical references (leaves 58-60).This study was performed to determine the bacterial loading of Kranji Catchment and Reservoir and how this will affect planned recreational use of Kranji Reservoir. Field and laboratory work was conducted in Singapore during the month of January 2009 to characterize the concentration of bacteria at sampling locations in the drainage system of Kranji Catchment and in Kranji Reservoir. Using this data, a first-order attenuation model was constructed and used to evaluate attenuation of bacteria while traveling through the drainage network to the reservoir. GIS tools used this model to predict areas of potential concern in one specific sub-catchment of Kranji Catchment. The USEPA WASP modeling program was used to determine fate and transport of bacteria throughout Kranji Reservoir based on bacteria concentrations flowing into the reservoir. These analyses led to the recommendation that farm run-off near the reservoir was the bacterial source of greatest concern. The relatively high concentrations coupled with short travel time, which diminishes opportunity for attenuation, resulted in high concentrations reaching the reservoir. Residential areas were found to contribute high concentrations of bacteria to the catchment, but due to relatively long travel times from the sources to the main body of the reservoir, have less of an effect on the bacterial concentrations of the main reservoir. Due to the uncharacteristically dry weather Singapore experienced during January 2009, the applicability of the results of this study to wet weather conditions is uncertain.by Kathleen B. Kerigan and Jessica M. Yeager.M.Eng
