The Yukon Water Board will continue to not allow waste rock from Mino mine to be used in any government construction projects while it deliberates whether or not the material is safe.
The board issued its order yesterday in response to concerns raised by the Little Salmon/Carmacks First Nation over the use of waste rock from the copper mine to line Tatchun Creek as part of a bridge replacement project.
When it comes to that particular project, the Yukon government has been ordered to test the waste rock more and monitor Tatchun Creek.
“The manner by which the logistics, assessment licensing and implementation of the Tatchun Creek bridge project evolved, resulted in an unclear state of understanding of the impacts of the project upon a valuable aquatic system,” the board’s decision document says.
Reconstruction of the Tatchun Creek bridge, just north of Carmacks on the Klondike Highway, began this spring.
A recent study has found that even trace amounts of copper in salmon habitat can affect the fish’s ability to navigate and detect predators.
Tatchun Creek is considered a highly productive chinook spawning stream, according to the Yukon Salmon Sub-Committee.
The First Nation approached the water board in late May. It argued that the mine rock does not meet the requirement for the water licence and that testing of the rock has not been adequate enough to prove it will not hurt the environment.
The government countered that the rock is “zero grade,” which means it does not leach metal.
Previous sampling and analysis of rip-rap were done by by third parties other than the Yukon government, the board says in its order.
“The board considers it the responsibility of the licensee to conduct its own sampling and analysis program, allowing for direct verification of the veracity of the results,” the decision document says.
“Sampling protocols and criteria for the rip-rap in question were unclear and inadequately documented. Further, given the importance of the receiving environment and the deviation of the source material origin, the board expects all sampling to be conducted in a matter that identifies the maximum possible effect of the rip-rap within the aquatic system.”
If it’s found that the rock has a negative impact on the environment, the board says it may order corrective action. For now, it needs more information.
It has promised a final decision by June 18. The order will remain in place until at least that date, though the board reserves the right to extend the deadline.
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