The proposed Carmacks Copper heap-leach mine will have to undergo another review by the Yukon Environmental and Socio-economic Assessment Board.
It’s another setback for Copper North, the Vancouver-based exploration junior that’s pushing the project.
It wanted to amend its earlier decision document and mine licence rather than face another full screening of the project.
But the territory’s assessors disagreed.
They’re sending the project back to the board’s executive committee, which provides a more thorough review than what’s offered at the regional level.
“Our goal is to not take any longer than necessary to do a full assessment,” said YESAB chair Stephen Mills.
“But it is a large project and we know it’s controversial. We want to make sure we meet all our obligations under the legislation. And the company’s got a bit of work to do before it gets a proposal to us and we start our screening.”
In the fall of 2008, it looked as if the Carmacks open-pit copper mine would soon become reality, to the dismay of conservationists and the nearby Little Salmon/Carmacks First Nation.
Copper North’s predecessor, Western Copper, had cleared the assessment board with the proposed heap-leach project and had also won government approval to build the mine.
Then the Yukon Water Board refused to issue a water licence. It worried the mine plan depended on “unproven technologies” that could pollute the Yukon River’s salmon-bearing tributaries.
The company wanted to douse massive piles of ore with sulphuric acid to separate the copper from the rock, then cleanse the pile with an alkaline solution. This design is called an acid heap leach.
The technique has been used, employing different chemicals, to separate gold from ore at the Yukon’s Brewery Creek mine. But a copper heap leach has never been done on a commercial basis in a northern environment.
Copper is particularly dangerous to salmon. It harms the fish’s sense of smell, which in turn hampers the salmon’s ability to navigate.
Western Copper fought the water board ruling in the courts, arguing the board had overstepped its authority.
But Yukon Supreme Court Justice Ronald Veale disagreed, concluding that to force the water board to agree with the assessment board’s findings “would completely eviscerate the licensing role” of the board.
Western Copper planned to appeal this decision. Then last fall, it spun off Copper North as a new company to handle the Carmacks project.
In January, Copper North dropped the court appeal.
In March, the company announced improvements to its heap-leach plans. Additional liners would be placed within ore piles to prevent pockets of acid from going untreated, and the company’s water models have been beefed-up.
The rest of the project remains unchanged, the company said in a news release this week.
Copper North plans to submit its new project proposal for assessment by the fall.
It also intends to release new plans to the Yukon Water Board at that time.
Beyond issuing news releases, Copper North has remained tight-lipped about its future plans.
Its president and CEO, Sally Eyre, has declined several interview requests.
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