Howard Cumberland is a marine scientist with 30 years of environmental consulting experience. working in the coastal zone on waterfront development and contaminated sediment programs where his responsibilities include developing and implementing redevelopment strategies, remedial investigations, remedial design and remedial implementation, as well as, working with legal counsel on allocation assessment, natural resource damage assessments (NRDA), negotiating and permitting with multiple regulatory and resource agencies, and PRP group negotiation strategies associated with contaminated sediments and waterfront development activities.
Don River Restoration Remedial Design and Action by Howard L Cumberland, Dogus Meric, and Danielle Thorson
The City of Toronto, the Province of Ontario, and the Government of Canada are undertaking a $1.25B redevelopment effort of the Port Lands as part of the Waterfront Toronto Port Lands Flood Protection and Enabling Infrastructure (PLFPEI) Project. The Port Lands consist of 1,000-acres on the shore of Lake Ontario, immediately east of downtown Toronto. The area was man-made through decades of infilling of historic wetlands and has historically been used for heavy industry. Contaminants of concern primarily include petroleum hydrocarbons, NAPLs and metals. Much of the area is within the flood plain of the Don River and therefore flood protection must be created before the area can be fully redeveloped as a proposed mix of residential and commercial. To achieve the project goals of redevelopment and flood protection, the design and construction of a new naturalized River Valley connecting the existing Don River to Lake Ontario by removing filled areas is required. Risk management measures (RMMs) associated with the River Valley are incorporated into the design to ensure the long-term protection of the newly created surface water features from potential future contaminant discharges. Geosyntec is the engineer of record for multiple upland and in-water RMMs on the Waterfront Toronto PLFPEI Project. The basis of RMM design was built upon the proposed layout of the naturalized river channel and surrounding park land, comprehensive geotechnical and environmental site investigations, and limitations of construction. The RMMs are designed to isolate and prevent migration of contaminants to the new Don River area and include a combination of vertical barriers such as:
The design was developed to not only meet the environmental requirements but to also facilitate integration of other aspects of the Port Land redevelopment including bridges, recreational areas, utility crossings, and construction and long-term maintenance of the naturalized river finishes and wetlands. This presentation provides an overview of the design and construction of these RMMs and lessons learned.