Late last year, the BBRSDA Board of Directors funded a hydrological analysis of a potential tailings storage facility (TSF) failure at the proposed Pebble Mine in the headwaters of Bristol Bay. Based on the scoping period of the mine’s permitting process, it was clear that the Draft Environmental Impact Statement (EIS) would not even consider the impacts of a major TSF failure. Which is confounding, since it has always been one of the most critical questions surrounding the potential environmental impact of any open pit mine in the region and so one would think an impartial EIS document written by the U.S. Army Corps of Engineers would include such an analysis.
The analysis is based on 28 actual failures at tailings storage facilities around the world and a highly detailed hydrological model that estimates how much material would be deposited downstream across a range of failure scenarios. The work was performed by a team of researchers from Lynker Technologies and The Nature Conservancy, led by Dr. Cameron Wobus.