FEASIBILITY OF MODELING REMEDIAL MEASURES FOR MICROBIOLOGICAL POLLUTION OF THE ST-CLAIR RIVER AT SARNIA BAY

A regular grid finite difference hydrodynamic model, which includes th e advective acceleration and eddy viscosity terms, was used to predict the circulation in the nearshore areas around Sarnia Bay. Coupled wit h the hydrodynamic model, a two-dimensional pollutant transport and fa te model, which included the advection, diffusion, and decay terms, wa s used to predict the spatial and temporal distributions of indicator bacteria. This modeling system allowed time dependent inflow/outflow d ischarges and bacteria fluxes from storm sewers, combined sewer overfl ows, and tributaries. Cases of dry weather loading, storm lending, and post recovery (i.e., after a rain event) were simulated for a number of hypothetical remedial options including the relocation of storm sew er outfalls and placement of a deflector barrier at the mouth of Sarni a Bay. The planning-level modeling system, which was partially calibra ted and verified for the existing conditions in Sarnia Bay, was found to be an effective tool for screening remedial options for mitigation of bacteriological pollution in Sarnia Bay.