Distress over pollution of natural water courses by industrial and domestic wastes is causing national concern. However, wastes must be disposed of by some method and these natural water courses have been and still are obvious sources for disposal. By careful study of the natural capacity of rivers and streams for assimilation of wastes, they can be used for disposal as long as this capacity is not exceeded. One method of determining this capacity without destroying the water course is by modeling the system mathematically to determine limits of pollution. This thesis contains the results of a preliminary study on the effect of the new Annacis Island Treatment Plant on coliform concentrations in the Fraser Estuary from Barnston Island to Garry Point. Mathematical formulas predicting coliform concentrations were used to computer simulate coliform profiles on the river. These results were then compared to present measured concentrations in the Estuary. Once a correlation between measured and simulated concentrations was established the effect of future discharges to the system could be simulated on the computer. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate