The controversial Pebble Mine prospect has provoked a large amount of press within Alaska due to its size, profit potential, and the risk it presents to essential salmon habitat. The potential for the development of other large mines nearby greatly magnifies the positive and negative impacts of this mine. Mining claims in the immediate vicinity cover over 500,000 acres, and are held by a number of different companies (see below). Developing these nearby prospects could help sustain longer term economic benefits of the mining infrastructure needed at Pebble, but they could also create cumulative environmental impacts that compound the impact of individual mines.
There is currently little to no mining infrastructure in this region, and the cost to build it would be high. If the Pebble Mine development goes forward as planned, the accompanying roads, port, and access to electrical power would dramatically lower the economic barriers to entry for opening nearby mining claims. Other mines could benefit directly from the use of Pebble’s infrastructure, as well as indirectly from an increase in mining expertise and experience in the region.
This piggybacking effect could significantly amplify impacts on water quality and fisheries in the region. In the “best-case” scenario, each mine would impact the environment with limited scope and the total effect on the region would be no more than the sum of the effects of individual mines. This could still include problems such as acid mine drainage, habitat destruction, and negative impacts on water quality in the region. However, with each additional mine, the risks of a catastrophic failure such as an acid-containing tailings dam collapse, increases and the impacts on water quality in the Bristol Bay watershed add up. Likewise, each mine would most likely destroy or negatively impact some amount of fish habitat nearby. Because of the vital importance of maintaining genetic diversity of salmon stocks, extensive mining in this area puts at risk the most productive salmon fishery in the world.