Detour Lake mine: tailings impoundment areas

Summary#

These are final regulations that add eight water bodies near the Detour Lake mine to Schedule 2 of the Metal and Diamond Mining Effluent Regulations. That change lets the mine operator dispose of mine waste in those waters for the West Detour Project, resulting in the loss of 1.9 hectares of fish habitat but requiring a compensation plan expected to create 2.9 hectares. The regulations were registered on June 10, 2024 and published on June 19, 2024.

What it does#

• Adds two specific stretches of streams and one defined area (together eight water bodies) near the Detour Lake mine to Schedule 2 of the Metal and Diamond Mining Effluent Regulations, designating them as tailings impoundment areas (TIAs).
• Authorizes the deposit of mine waste (non-acid generating mine rock and overburden) into those waters to make room for new and expanded waste rock stockpiles linked to the mine expansion.
• Requires the mine owner to develop and have approved a fish habitat compensation plan (FHCP) under the Metal and Diamond Mining Effluent Regulations before any mine waste is placed in those waters.
• Requires a financial guarantee (an irrevocable letter of credit or equivalent) to cover FHCP implementation costs, estimated at $3.09 million over 2023 to 2033.
• The regulations take effect on the day they were registered (June 10, 2024).

Who's affected#

• Kirkland Lake Gold Ltd (the project proponent) and its owner Agnico Eagle Mines Limited — they will build the new stockpiles and pay for the FHCP.
• Local fish and aquatic habitat: the change allows the permanent loss of 1.9 hectares of fish habitat in the listed waters.
• Nearby Indigenous communities and organizations that were consulted: Moose Cree First Nation, Taykwa Tagamou Nation, Apitipi Anicinapek Nation, Cree Nation Government, and the Métis Nation of Ontario — they have raised concerns and took part in technical review.
• Regulators and the public who use or rely on the affected waterways, including recreational and commercial fishers; the Department of Fisheries and Oceans and Environment and Climate Change Canada will oversee approvals and compliance.

Why it matters#

• It removes a legal barrier so the Detour Lake mine expansion can use nearby fish-frequented waters for mine waste storage. That directly enables the project to handle about 135 million tonnes of mine rock over its life and helps extend mine operations (the project is expected to extend operations to 2042).
• There is a real, measurable habitat loss (1.9 hectares). The government requires an FHCP intended to create 2.9 hectares of new or improved habitat, giving a planned net gain of about 1 hectare — but the real-world success of such offsets can take years and is uncertain.
• The FHCP must be funded (about $3.09 million) and monitored; the government will inspect compliance. Local Indigenous interests and downstream users were involved in consultation, and some raised technical and cultural concerns that influenced the plan.
• If you use or rely on fisheries or watershed resources in that area, this regulation changes how the site will be managed and requires ongoing monitoring and compensation to address the environmental effects.