At Randle Reef in Ontario’s Hamilton Harbour, one of the most contaminated underwater sites on the Canadian side of the Great Lakes, construction of a 6.2-hectare double-walled steel containment structure is nearing completion, and phase two, the dredging of contaminated sediment, will begin this summer.
Marking phase 2 for the $139-million project will mean sucking up 60 hectares of underwater coal tar and other contaminants to deposit it into the containment structure. The work will be a joint-venture contract between Milestone Environmental Contracting Inc. and Fraser River Pile & Dredge Inc.
Federal Environment Minister Catherine McKenna acknowledged the project milestone for Randle Reef on Twitter, stating that, “Collaboration is at the heart of this project. Together, we are going to clean up Hamilton Harbour and take it off the list of Great Lakes Areas of Concern.”
In spending updates announced by the federal government in April 2018, however, spending on the Randle Reef remediation project will decrease by $15.2 million.
The contamination of Randle Reef is the result of multiple historical sources over a period of more than 150 years. Pollution sources include coal gasification, petroleum refining, steel making and associated coking, municipal waste, sewage effluent, and overland drainage.
The cleanup project is divided into three phases. Phase 1 began in September 2015 with the reconstruction of an adjacent harbour pier wall. The in-water construction of the facility began in May 2016 and was expected to be completed by the end of 2017.
Phase 3 of the remediation project involves compacting the contained sediment and removing the water from it, followed by constructing an impermeable cap on the facility. This final phase is expected to begin in 2020 and be completed in 2022.
The Randle Reef facility, once filled with contaminated sediment and capped, will be utilized as a port facility. This approach of containing contaminated sediment in an engineered facility and creating useable land is a first in Canada.