Macassa Mine: Two Streams Added as TIAs

Summary#

These final regulations add two small, unnamed streams near Kirkland Lake, Ontario, to Schedule 2 of the Metal and Diamond Mining Effluent Regulations. That change lets Agnico Eagle Mines Limited use those streams as tailings impoundment areas for the Macassa mine expansion. The regulations were registered (and came into force) on March 6, 2025, and were published in the Canada Gazette on March 26, 2025.

What it does#

• Lists two unnamed tributaries to Amikougami Creek (about 4 km west of the town of Kirkland Lake, Ontario) as tailings impoundment areas in Schedule 2 of the Metal and Diamond Mining Effluent Regulations.
• Authorizes the deposit of mine tailings into those listed waters for the Macassa mine, subject to the conditions already in the regulations.
• Allows the project to destroy a total of 0.46 hectare of fish habitat in those two tributaries.
• Requires the mine to have an approved fish habitat compensation plan (FHCP) before any tailings are placed in the listed waters. The FHCP for this project is designed to create 0.89 ha of new or improved habitat.
• Requires a financial security from the mine to guarantee the FHCP. The estimated cost for implementing the FHCP is $1.37 million.

Who's affected#

• Agnico Eagle Mines Limited, the mine operator seeking to expand the North Tailings Storage Facility at the Macassa mine.
• People who live in and around the town of Kirkland Lake, Ontario, and users of nearby lakes and streams.
• Nearby Indigenous communities that were consulted: Apitipi Anicinapek Nation, Matachewan First Nation, Beaverhouse First Nation, Temagami First Nation, Timiskaming First Nation, and the Métis Nation of Ontario. Some concerns were raised during consultation, particularly by Apitipi Anicinapek Nation.
• Federal departments involved in oversight and enforcement, including Environment and Climate Change Canada and Fisheries and Oceans Canada.
• Local fish and aquatic habitat in the affected tributaries (the department’s documents list small forage fish and other species present in the Amikougami Creek system).

Why it matters#

• Practically, the change clears a regulatory step that lets the Macassa mine expand its tailings storage and extend operations (the company expects about 15 more years of production from the expansion).
• It creates a trade-off: 0.46 hectare of existing fish habitat will be lost, but the required compensation measures aim to create 0.89 ha of habitat elsewhere. That compensation must be in place and funded (estimated $1.37 million) before tailings disposal can begin.
• Indigenous communities raised concerns about cumulative and historical impacts in the area. The government and the company say they engaged and offered funding to support Indigenous review of project documents.
• The amendment is site-specific. It does not change the rules for other mines. Federal agencies will monitor compliance and can take enforcement action if conditions are not met.