ENVIRONMENTAL OVERVIEW
CYANIDE: HOW DANGEROUS IS IT AND HOW WOULD IT BE HANDLED?
Cyanide needs to be handled properly to safeguard personnel and the environment. The International Cyanide Management Code provides guidelines for handling cyanide, from its manufacture to its transport, storage, use, and disposal. These guidelines have been key in the design of the proposed project. Dry sodium- cyanide briquettes would be shipped to Donlin in sealed steel ISO (International Standards Organization) tanks. It would then be dissolved into a weak, pH-controlled solution for use in the mill. The role of cyanide is to dissolve the gold so that it can be extracted. Once the gold is removed from the cyanide solution, the solution goes through a "cyanide destruction" process that reduces its concentration.
WHAT IF THERE WAS AN EARTHQUAKE? COULD THE TAILINGS DAM LEAK?
The dam would be engineered to withstand strong ground motion resulting from large earthquakes. This is the type of dam used at Fort Knox, which easily withstood the Denali Fault earthquake of 2002.
The tailings facility and dam would be lined to minimize any seepage. A seepage collection system would be in place to collect any seepage and pump it back to the tailings facility. Groundwater and surface water below the facility would be monitored on an ongoing basis.
