TORONTO (miningweekly.com) – Canada’s largest diversified miner, Teck Resources, on Thursday said that it would not build an 80 km pipeline at its Red Dog zinc/lead mine, near Kotzebue, Alaska, that would direct effluent from the Red Dog Creek to the Chukchi Sea.
In a filing with the US District Court for Alaska outlining the findings of an extensive study into the proposed pipeline, Teck Alaska had informed the court it is exercising its option not to build the pipeline.
The effluent pipeline study was conducted under a 2008 Settlement Agreement and consent decree, which resolved litigation under the Clean Water Act.
Under the agreement, Teck Alaska agreed to review the feasibility of constructing a pipeline to carry effluent from the Red Dog mine along the DeLong Mountain Transportation System (DMTS) to a marine discharge at, or near, the DMTS port site.
Teck said that its subsidiary undertook engineering, geotechnical, environmental and other studies to look at various pipeline options at a cost of $1.7-million.
That work determined that an underground pipeline was not a technically feasible option because it would be vulnerable to breakage due to ground movement caused by seasonal ground freezing and thawing.
Engineering and environmental studies determined that an above-ground pipeline is also not a viable option. While potentially technically feasible, there were no demonstrable environmental benefits, and it was determined that there would be increased environmental risks and impacts associated with pipeline construction and operation, energy use and emissions, and potential effects on caribou migration.
Further, the estimated $261-million capital cost of an above-ground pipeline would be prohibitive. As stipulated in the Consent Decree, Teck would pay a civil penalty of $8-million for not building the pipeline.
Red Dog currently releases water to Red Dog Creek that is treated at an on-site facility to meet the requirements of an Alaska Department of Environmental Conservation discharge permit and the effluent is said to be safe for both human health and the environment.
"Following extensive environmental and technical study, it is clear that a pipeline is not a viable option. More importantly, there is no clear environmental benefit to building a pipeline, as the treated water currently being released to Red Dog Creek meets stringent permit requirements and is fully protective of aquatic and human health.
“In fact, the creek is demonstrably healthier than it was before mining commenced, supporting a thriving fish population because of our water treatment programme,” Red Dog operations GM Henri Letient said.
Last year, Red Dog produced about 551 000 t of zinc and 96 700 t of lead in concentrates.