Technology Helps Reduce Sediment & Nutrient Loading Rates to Lake Simcoe

Nov. 30, 2022

The Town of Innisfil (Ontario) and Greenland Consulting Engineers applied for and coordinated the Innisfil Erosion and Advanced Sedimentation Pilot Project funded by the Federation of Canadian Municipalities. The project sought to assess advanced sedimentation technologies (ASTs) to reduce the sediment and nutrient loading rates to Lake Simcoe from runoff generated by development sites under various stages of construction. It was important that the AST be safe for fish and invertebrates as well as be able to work with existing infrastructure.

The Sleeping Lion Subdivision Development (Cortel Group) was the selected site and three stormwater management facilities (SWMFs) in their various stages of completion that would be used in the pilot. Clearflow Group, a 100% Indigenous-owned company with a long history of assisting industry in meeting regulatory compliance, was chosen to provide Gel Flocculant Block technology as a ready-to-use solution.  

Particle analysis was conducted on the stormwater to better understand the size and amount of TSS. Results can be seen in graph A where MH 94 represents the inflow and MH 2 the flow leaving the pond. The data indicates that during a heavy rainfall event the size of the particulate below 40 microns was substantial. Because of this, without the gel flocculants, it is likely that sediments carrying heavy metals and phosphorus would carried through and entered Lake Simcoe. An average of 90 per cent phosphorus reduction was achieved in the three SWMF’s.  

Innisfil development engineer Glenn Switzer was also very pleased with the results and said, “projects like these typically require substantial capital investment, using the Clearflow Gel flocculant [meant] we were able to optimize the use of our existing infrastructure. This saved time, money, and environmental impact. Treating stormwater has now become much more effective and affordable.” 

Clearflow Group | 780.410.1403 |