Should the Toronto Main Sewage Treatment Plant Outfall Be Moved Farther Offshore?
Efraim Halfon Abstract A fate model, TOXFATE, is coupled with a hydrodynamic model of the waters off the Toronto waterfront, Lake Ontario. The Toronto waterfront is here defined as a rectangular area, 48 km long by 10 km wide, of the lake delimited on the west by Etobicoke Creek and in the east by the Rouge River. Data were collected in 1987 in support of the Toronto Main Sewage Treatment Plant (STP) pilot site study, Municipal and Industrial Study for Abatement (MISA). It provides an excellent baseline database. The object of the fate-modeling study is to assess the change in organics concentration if loadings from the Main STP and other local sources were changed or the outfall location moved farther offshore. Loadings of contaminants from local sources in the Toronto waterfront area are between 0.5% to 25% of contaminants that enter Lake Ontario from other sources. Results show that if sources of local loadings were reduced, changes in water concentrations would be noticeable within
