The Pebble Mine proposal’s size, and potential to release acid drainage, makes it an unacceptable risk
From the fact sheet:
The Bristol Bay wild salmon fishery is at risk from plans to develop a massive open pit copper and gold mine at its headwaters.
The proposed Pebble mine straddles the headwaters of the Kvichak and Nushagak Rivers – the world’s two most productive wild sockeye salmon rivers. Based on current ore projections, the Pebble Project will be the largest copper and gold mine in North America, with an estimated footprint covering 54.4 square miles of the Bristol Bay watershed.
According to 2006 applications and the 2011 prefeasibility study, minimal mine plans would include:
- An open pit 2.5 miles wide and 2,000 feet deep.
- Generation of up to 10 billion tons of toxic mine waste, which would be permanently disposed of in an area that is currently productive salmon spawning and rearing grounds in the headwaters of Bristol Bay.
- Construction of several mammoth earthen dams, at least one of which is projected to be roughly 700 feet high – larger than the Three Gorges Dam in China – built to store the acid-generating mine tailings in perpetuity.
- The annual removal of over 35 billion gallons of surface water from salmon habitat.
- Construction of an 86-mile road with four parallel pipelines (carrying diesel fuel, wastewater, mine slurry and natural gas) crossing important salmon habitat, and linking the mine to the port.
- A 378 megawatt power plant.
A peer reviewed 2010 ecological risk assessment commissioned by The Nature Conservancy studied the impacts of such large-scale mining in the Bristol Bay region, and concluded that the risks to wild salmon populations are “very high,” and that it is cause for significant concern regarding the long-term abundance and sustainability of salmon in the region. It identified serious risks associated with water pollution from acid mine drainage, loss of important wild salmon habitat, and the loss of water in important salmon streams.