Following the decommissioning and rehabilitation of the Gaspé Copper mine in Quebec by previous owner Glencore Canada in 1999, Osisko Metals bought the project in July 2023, with the plan of potentially reopening it by the end of the decade.  

As part of these efforts, Osisko announced on Feb. 27 that it had recently formed a technical consultation committee and tasked it with devising a plan to dewater the Mount Copper open pit at the mine “as soon as possible” following past flooding, to permit “deeper in-pit” resource evaluation and geotechnical drilling of the pit and establish if it is possible to advance the project to commercial production. The mine is located near the town of Murdochville in Quebec’s Gaspé region.  

The committee, which is being guided by Ann Lamontagne, the company’s recently hired vice-president of environment and sustainable development, is also comprised of specialists from an array of organizations, including the secretariat of the Mi’gmawei Mawiomi First Nation and the Northern Gaspesie Water Council. Lamontagne’s first task in this new role will be to develop a safe plan to dewater the flooded pit and she will be in charge of all tasks associated with environmental monitoring and any impact studies that need to be conducted in order to progress to the permitting phase of the project. 

The dewatering plan will build upon earlier environmental studies carried out by Osisko in late 2023, which examined local fish species and habitats as well as vegetation in the area’s riparian zone. A geomorphological study was also completed to better understand the area’s stream banks and flow beds to pinpoint potential sites of erosion. Additionally, water quality analyses were done at the Mount Copper pit, which deemed the flood water to be environmentally safe for discharge. The company stated it will take measures to protect the local York River and its diverse salmon population, which is located roughly three kilometres downstream from the mine site. Once completed, the dewatering plan will be shared with the public to inform the local population of any mitigation efforts.  

“We are committed to developing the Gaspé Copper project in collaboration with all stakeholders in the region, while meeting the highest standards of environmental management,” said Robert Wares, chairman and chief executive officer of Osisko Metals, in the Feb. 27 press release. 

The company reported that the copper project’s deposit contains 3.1 billion pounds of copper sulfide in the inferred category, which it said is currently the largest untapped copper resource located in eastern North America.  

The mine, which first began production in 1955, yielded a total of 150 million tonnes of ore averaging 0.87 per cent copper and produced 2.8 million tonnes of copper anode before operations ceased in 1999. The project’s mine, mill and smelter complex were dismantled, and the site has been in care and maintenance since then. Osisko estimates that restarting commercial production at the mine could commence around 2030.