MOEE Procedure F-5-5 required the City of Ottawa to develop a Pollution Prevention and Control Plan (PPCP) to characterize and address issues associated with floatables discharged from the City’s combined sewer system. In 2008, to support development of the PPCP, the City tasked consultants G. A. Clark & Associates and HydroQual, Inc. with conducting an investigation addressing the sources, pathways, and ultimate fate of combined-sewer floatables in Ottawa. This study involved field sampling, as well as the development and application of an analytical model of floatables fate and transport, to evaluate current conditions and the impact of planned future improvements and other potentially cost-effective alternatives. Results of this study formed the basis for the City’s plan to control and monitor floatables.
The approach and methods developed and applied in Ottawa may represent an archetype for other municipalities in Ontario and elsewhere. This paper describes the approach and summarizes the findings of both the initial 2008 study and subsequent monitoring and analyses.