Located in the southwest corner of Hamilton Harbour on Lake Ontario, Randle Reef is the largest contaminated sediment site on the Canadian side of the Great Lakes. Stage 2 of the Randle Reef project is now complete. All of the contaminated sediment has been successfully managed at the site. The 3rd and final stage will be capping the ECF. The Randle Reef Remediation Project is a joint initiative involving the Government of Canada, the Province of Ontario, City of Hamilton, Halton Region, City of Burlington, Hamilton-Oshawa Port Authority and Stelco.

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Randle Reef is the largest contaminated sediment site on the Canadian side of the Great Lakes, located here in Hamilton Harbour, an Area of Concern under the Great Lakes Water Quality Agreement.

The Government of Canada, along with its partners, is cleaning up this site. There are three main stages to the project. In Stage 1, we built an Engineered Containment Facility or "ECF" and in Stage 2, we removed contaminated sediment from Randle Reef and placed it in the ECF.

Let's take a closer look at the Stage 2 process. As you can see, the ECF is situated over top of a large portion of the most contaminated sediment, shown in red.

The remaining red, orange and yellow areas signify severely and moderately contaminated sediments, which were dredged and placed within the facility. A new hydraulic dredge was built specifically for this project.

You can see from the view of the dredge cabin, the operator uses GPS and a joystick like controller to manoeuvre the dredge cutter head to remove the targeted sediment. This dredge acts much like a vacuum cleaner.

It uses a cutter head to loosen contaminated sediment and creates a sediment-water slurry, which is pumped through a large pipeline and discharged into the ECF. Air, water and sediment quality was monitored throughout dredging to confirm that no adverse impacts occurred during the project.

Prior to the start of dredging, debris was removed from the contaminated area. To reduce the potential for air emissions, the slurry was pumped through a pipeline and discharged into the ECF.

The contaminated water in the ECF was then pumped to a water treatment plant built specifically for the project. The treatment plant removed any remaining sediment and dissolved contaminants were treated prior to discharging clean water back into the Harbour.

Upon completion of the dredging, samples from the remaining sediment were collected and analyzed, confirming that the clean-up target for the project has been met. The ECF structure creates a channel between the outer wall and the Stelco property.

A 3-layer isolation cap was installed to cover and safely contain the contaminated sediment in the channel. The first layer is comprised of reactive core mats, which contain reactive materials between geotextile fabric, used to bind contaminants.

The second layer, which is a 65 cm layer of sand, with 3% organic carbon, serves to bind any contaminants. Finally, the cap is covered by rip-rap to provide protection from erosion.

With the completion of Stage 2, all the contaminated sediment has been successfully managed at the Randle Reef site. This is a significant step for the project, bringing us one step closer to restoring the Hamilton Harbour Area of Concern.

In Stage 3 of the project, an environmental cap will be placed atop the ECF, completing the project.