Ekati Mine Tailings Areas Authorized

Summary#

These final rules, the Regulations Amending the Metal and Diamond Mining Effluent Regulations, list 3 waterbodies used by the Ekati Diamond Mine as authorized tailings impoundment areas (so mine waste can continue to be deposited there). They also let mine operators use alternative financial guarantees (for example, performance bonds) instead of only an irrevocable letter of credit. The amendments came into force on February 21, 2022 and were published in the Canada Gazette on March 2, 2022.

What it does#

• Adds 3 waterbodies to Schedule 2 of the Metal and Diamond Mining Effluent Regulations, formally designating them as tailings impoundment areas:
  • Cells D and E of the Long Lake Containment Facility (part of Long Lake).
  • Two Rock Sedimentation Pond (formerly Two Rock Lake).
• Allows the mine owner or operator to provide other equivalent financial guarantees (for example, a performance bond) instead of only an irrevocable letter of credit when submitting a fish habitat compensation plan.
• Fixes a small error in geographic coordinates for an unrelated site listed in Schedule 2.

Who's affected#

• The main direct party is the mine operator, Arctic Canadian Diamond Company, which runs the Ekati Diamond Mine near Yellowknife, Northwest Territories.
• Local fish and the ecosystems in the affected waterbodies (Cells D and E of Long Lake and Two Rock Sedimentation Pond).
• Nearby Indigenous communities and organizations who were consulted (for example, the Yellowknives Dene First Nation and the North Slave Métis Alliance were engaged).
• Regulators and anyone tracking compliance with the Fisheries Act and the Metal and Diamond Mining Effluent Regulations.

Why it matters#

• These changes legally allow the Ekati mine to keep using the listed lakes and ponds for mine waste. That is not a new activity — the mining operation has used these facilities for years — but the listing makes the use explicitly authorized under the regulations.
• The listing acknowledges a permanent loss of fish habitat already accounted for: Cells D and E together represent up to 95 hectares of habitat loss, and the sedimentation pond has species-specific losses of 3.73 ha, 4.62 ha, 0.99 ha, and 1.18 ha for different fish species. The government says those losses were already compensated in past approvals.
• The amendments let operators use different forms of financial security (e.g., performance bonds), which may reduce administrative burden or cost for operators while keeping compensation guarantees in place.
• The government says no new environmental harm or new costs to business are expected because the changes reflect existing practices and earlier compensation (the original compensation measures cost Can$1.5 million and were implemented between 1997 and 2001).