Advancing Together With Barrick Gold

Environment Water management during closure done right at Eskay Creek

Water management is as crucial and important to Barrick after a mine closes as it is during a mine's active life cycle. We must return the environment to a stable condition in accordance with strict permit requirements, moving towards the ultimate goal of protecting the long-term viability of the land and water.

"We recognize that our responsibility to local stakeholders and the environment doesn't end when mining activity does," says Patrick Malone, Barrick's Vice President of Environment."Part of building partnerships of real depth means making good on our commitment to return the land and water to a stable state, and our Eskay Creek closure site is a great example of that."

Located in northern British Columbia, Canada, Eskay Creek operated from 1994 through 2008 and produced more than 3.3 million ounces of gold. The operation benefited the Tahltan First Nation, providing employment and supplier contract opportunities. Thirty-four percent of the mine's employees were from First Nations communities.

During the closure phase, the Tahltan Nation Development Corporation and other Tahltan-owned businesses actively participated in areas such as road maintenance, labor, material movement and food services.

Today, most of the earthwork, re-vegetation and re-contouring of slopes is complete.

Because Eskay Creek is located next to two deep, non-fish-bearing lakes, the operators were able to store tailings—the fine materials left over from processing ore—and waste rock under water, cutting off the oxygen that would otherwise have caused them to generate acid.

Like many mines, Eskay Creek contained sulfur-based rocks and tailings that can potentially generate acidic water if left exposed to air and water. Mine operators must prevent this from occurring, and one of the more common ways to do so is to eliminate water or oxygen from the equation.

Because Eskay Creek is located next to two deep, non-fish-bearing lakes, the operators were able to store tailings—the fine materials left over from processing ore—and waste rock under water, cutting off the oxygen that could otherwise have caused them to generate acid. The two lakes, Tom Mackay Lake and Albino Lake, never contained fish because the streams and creeks that flow from them are rocky and the water flowing through them is too fast-moving for fish to swim upstream. The lakes are monitored for water quality on a quarterly basis in accordance with permit requirements.

From mine closure in 2008 and for many years thereafter, Barrick staff sampled and analyzed water quality—weekly in the case of Tom Mackay Lake and Albino Lake, and daily in the case of the attenuation ponds into which water from the underground mine flows. After the quality of the water in the two lakes and in the attenuation ponds had stabilized, with all monitoring criteria well below permit requirements, Barrick sought and obtained a decrease in monitoring frequency at these locations. This in turn allowed Barrick to demobilize its staff from the site.

Despite the advanced closure status of the site, Barrick will continue to be responsible for Eskay Creek for the foreseeable future, or until new owners are found. "Site relinquishment was once the goal of every closure program; however, in many jurisdictions that is simply no longer attainable," says Dan Bornstein, Barrick's Director for Mine Closure Strategy and British Columbia Properties. "Companies need to be more creative now than ever before in finding new owners and new uses for their brownfield properties that gain the support of local communities in order to achieve something akin to site relinquishment."