Photo Courtesy Pebble Limited Partnership
Pebble: Conscientious of impacts amid decision
In spite of the current uncertainty regarding a final decision by the Envi - ronmental Protection Agency, North- ern Dynasty Minerals Ltd. and Pebble Limited Partnership has outlined the potential locations and solutions of a tailings pond for the proposed world- class copper-gold-silver-rhenium mine in Southwest Alaska. To alleviate concerns over the environmental impacts a mine like Pebble would have on the surround- ing waters, especially the Bristol Bay watershed that supports the largest sockeye salmon fishery in the world, Northern Dynasty has opted to take
the initiative and address these con- cerns. At a large hardrock mine such as being proposed for Pebble, once the sought-after minerals are extracted, the leftover tailings are stored in a large containment pond. The most sustainable tailing and rock waste management method presently is to stably contain the ma- terial, minimize the water and ener- gy inputs, as well as the surface foot- print of wastes, and seek alternative solutions. Currently, the greatest risk of tail- ings ponds is dam failure, with one of
the major causes being due to water overflow or overtopping, according to the paper "Regional Distribution and Causes of Global Mine Tailings and Dam Failures." "The failure of a tailings storage facility around the world is rare," said Northern Dynasty President and CEO Ron Thiessen. "When one does occur, however, failure is often caused by the accumulation of too much water." For the proposed mine at Pebble, this concern has been addressed with an overabundance of water treatment capacity to ensure that water levels
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The Alaska Miner
Fall 2022
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