Submitted by Kristin O’Connor, Hamilton Harbour Remedial Action Plan and Roger Santiago, Environment and Climate Change Canada
Hamilton Harbour was identified in 1987 as an Area of Concern under the Great Lakes Water Quality Agreement because of significant water quality impairment, a legacy of intensive industrial and urban development. The Randle Reef Remediation Project is focused on isolating a site of historically highly contaminated sediment to stop the impact on fish and wildlife. With over 150 years of contamination at this site, a shared responsibility model was adopted in 2012 with the Government of Canada, the Government of Ontario, and the local community participating and funding equally in the design and implementation of a $138.9M solution. ECCC leads this three stage initiative with our project partners to manage this Hamilton Harbour Remedial Action Plan priority.
Stage 1 (build the box) finished in 2018 with a 6.2 hectare Engineered Containment Facility (ECF) constructed around the most severely contaminated sediments within a double-walled sheet piling structure. This is equivalent to 7.5 football fields and close to 75% of the contamination was safely contained at this point.
Stage 2 (fill the box) activities were effectively completed in 2021 once environmental dredging and sediment capping ended. To reduce the potential for air emissions, most of the 450,000 cubic metres of contaminated sediment was sucked up into a pipeline and discharged under water within the ECF. The contaminated water in the ECF was then pumped to a specially built water treatment plant prior to discharging clean water back into the Harbour. Any remaining contaminated sediment outside the ECF were managed in place using a sand isolation cap.
Stage 3 (put a lid of the box) will involve constructing a multi-layered environmental top over the ECF to isolate the contaminated sediment. Construction began in September 2023 and is expected to be completed by the fall of 2025. Once completed, the site will be turned over to the Hamilton-Oshawa Port Authority who will own, monitor, and maintain the site as a port facility.
Environmental monitoring has been an important component of all stages. Monitoring will continue to evaluate the structure and capped areas for 15 years post-remediation. A long-term indicator monitoring study uses six lines of evidence with ten years of baseline data before work started and will continue up to 15 years after project completion.
We invite you to check out randlereef.ca for more information, including links for two informative YouTube videos for deeper looks into Stage 1 and 2.