💦 Town Receives Approval for Amended Wastewater Treatment Outfall Construction Plan
The Town of The Blue Mountains would like to provide an update on the Thornbury Wastewater Treatment Plant Assembly and Installation project.
A portion of the turbidity curtain system used to limit the spread of suspended sediment generated by dredging was damaged beyond repair by sustained high winds and wave action on Georgian Bay during the weekend of July 18-19.
Over the past week, the Town’s contractor has paused dredging operations and performed a thorough inspection of the recovered sections of curtain to determine how much of it could be effectively redeployed. The usable sections, along with additional curtains stored at Lora Bay Park that were to be used as dredging progressed into deeper water, will be redeployed in a modified configuration to support completion of the remaining dredging work. The revised configuration will place usable curtain sections along both sides of the dredging corridor. The offshore end will remain open to reduce pressure from wind and waves, improving the system’s resilience during changing lake conditions. The contractor plans to begin reinstalling the turbidity curtain system and resuming dredging as early as Thursday, July 30, pending suitable weather and water conditions.
Maintaining environmental and public health remains paramount in the amended plan. Continuous turbidity monitoring will remain in place during dredging. If the monitoring system detects turbidity levels in exceedance of approved thresholds, response actions will be implemented, up to and including temporary suspension of dredging. The Town has also engaged a third-party consultant to complete water quality testing periodically along the shoreline outside the dredging corridor.
Turbidity curtains are custom manufactured for each project based on measured water depths. Ordering new curtains to replace the damaged material is not feasible within the approved project budget. In addition, the time required to order, produce and receive new curtains could put the project at risk of exceeding the permitted timeframe for completing in-water work.
This amended plan has been reviewed and approved by the Town’s engineering consultant, the Ministry of Natural Resources, the Department of Fisheries and Oceans, and local Conservation Authorities.
Once work resumes, dredging is expected to take approximately 15 working days to complete. The public will likely notice temporary visible turbidity or cloudiness in the water during the remaining dredging work. Turbidity curtains are not designed to be fully impermeable, however the majority of suspended sediment is expected to be contained within the curtained area.
Ongoing updates regarding the project will be posted to the Town’s project web page and emailed directly to project subscribers.
