Redevelopment of Commercial Land to Mixed-Use High-Rise Developments – Toronto, Ontario
The proposed project will include the redevelopment of a commercial land, which is situated in the Toronto’s Waterfront, for mixed-use residential, retail and office space including a multi-story high-rise tower with four levels of undergrounds parking. The project has the unique challenge of being close proximity to Lake Ontario with high water table, adjacent to major transport corridor and high-rise buildings.
Scope Of Work
B.I.G. Consulting Inc. (BIG) was retained to provide environmental services including hydrogeological assessment to support the proposed development.
BIG’s approach was to adopt a subsurface investigation program that focused on extensive site characterization work including borehole drilling, groundwater monitoring well installation and pump test to obtain the necessary data to support the Phase Two ESA and hydrogeological investigations. Carrying out the field investigations concurrently allowed for efficient and cost-effective management of the field program. The results of the investigation indicated dissolved VOC plume was present at significant depths and Risk Assessment approach was adopted to manage the impacts. As an alternative to costly site cleanup activities, the Risk Assessment approach can be applied to determine the level of exposure for an individual site and establish risk-based clean-up criteria. The Risk Assessment study concluded that risk management mechanisms will be required to eliminate or block the contaminant vapour migration in to the future building. As a result, a unique vapour mitigation system was designed with the selection of a membrane that would provide water-tight properties, puncture resistance, and eliminate vapour intrusion in to the building against several VOC parameters.