Notice of Completion for the Gould Copper Mine Rehabilitation Project

The Ministry of Mines has completed our assessment for the proposed rehabilitation of mine hazards at the Gould Copper Mine (AMIS #07872). The mine is situated in Gould Township, approximately 70 km east of Sault Ste. Marie and 45 km north of Thessalon, Ontario. The mine is accessed via a narrow access trail west of Highway 129.

The purpose of the project is to rehabilitate the mine hazards at the Gould Copper Mine to eliminate the risk to the public and the environment. Mine hazards proposed for rehabilitation include two raises, an adit, a crown pillar and remnants of mine infrastructure. The mine is known to be frequented by the public. Entering the underground workings of the mine can pose fatal consequences due to dangers associated with unstable ground, insufficient oxygen, or wildlife. Similarly, building debris remaining from historical mine infrastructure may contain hazardous material that may be harmful if handled improperly. The objective of the rehabilitation activities is to permanently prevent inadvertent access to all mine openings to surface and remove remaining building material and debris associated with the historical mining activities.

Several studies have been completed to assist with determining the preferred rehabilitation strategy. A bat acoustic study confirmed the presence of bat species at risk within the underground workings, specifically at the adit location. The study concluded that the underground workings of the mine have the potential to be utilized by bats as a hibernaculum. A geotechnical investigation was completed to determine the long-term stability of the crown pillars and conditions of the openings to surface remaining at the site. The investigation concluded that the crown pillar associated with the adit is not long-term stable and progressive failure of the adit brow and crown pillar have occurred. As a result, bat-friendly rehabilitation measures (i.e., stainless steel gate) are not feasible as it would not address the long-term stability of the adit crown pillar zone.

The proposed rehabilitation approach for the adit is to backfill a minimum of 10 metres of the adit from the brow to support the crown pillar and prevent it from unravelling. The backfill will also be used as the rehabilitation measure to permanently prevent access to the adit but will result in the permanent loss of potential bat overwintering habitat. The preferred rehabilitation strategy for the two raises is to backfill using a combination of cemented and uncemented material to maintain long-term stability. Mine infrastructure to be decommissioned includes the hydro substation, mill site foundations, water tank, and two steel barrels. Disturbed areas will be allowed to revegetate naturally and return to pre- disturbance conditions. The work will be completed between June 10 and July 10, 2024.

The undertaking has been assessed as a Category C project, in accordance with the Class Environmental Assessment for Ministry of Northern Development and Mines Activities under the Mining Act (Class EA).

Public consultation:

You are invited to provide any new information or concerns related to this project by November 28, 2023. To receive additional information, or to submit new concerns regarding the project, please contact:

Michaela Haring, Environmental Planner
933 Ramsey Lake Road
Sudbury, ON, P3E 6B5
Telephone: 1-249-885-3631
Email: Michaela.Haring2@ontario.ca

After November 28, 2023, if MINES is satisfied that there are no outstanding concerns, the project will be implemented as planned without notice.