Application of Modeling Tools to Assess Receiving Water Impacts

York Region has developed an innovative multi-component approach to provide sewage servicing for growth in an area of the Region, including a new Water Reclamation Centre with advanced membrane treatment to achieve an ultra-low total phosphorus concentration for discharge to surface water. The purpose of this paper is to show how various modeling tools were constructed and used to evaluate surface water effects resulting from the high quality effluent discharge of the new Water Reclamation Centre proposed to be located in the Lake Simcoe (Ontario, Canada) watershed. Examples of the modeling results are provided, including water quantity, water quality and effects on the thermal regime, ice regime and aquatic habitat. The modeling activities were useful to meet the needs of an extensive environmental assessment process.