The objectives of this project are to rate three approaches for deriving effluent requirements; create a prioritized list of improvement steps; apply a watershed-level model to determine treatment plant requirements; and provide recommendations for deriving effluent requirements in Ontario. Results of a two-part stakeholder survey show that until advancements are made, compromise is necessary when selecting an approach for deriving effluent requirements, as no one approach meets all the evaluation criteria. However, the necessary steps toward improvement are relatively clear and require multi-disciplinary input. When the watershed-level modelling approach was applied, it was found that although there are challenges that must be addressed, overall, it appears advantageous to use a tool such as watershed-level models for the purpose of deriving effluent requirements in Ontario. / Natural Sciences and Engineering Research Council of Canada, Ontario Graduate Scholarship Program