are a waste product that has no financial gain to a mineral operator at that particular point in time." They consist of ground rock and chemical leftovers from mineral extraction. The toxicity varies depending on composition. Dams and embankments are built to contain the slurry of tailings, and often require indefinite water treatment, an ultimately unattainable task.
When storage of these tailings is compromised, they can flood communities and release harmful mining leftovers into the surrounding rivers and soils. An average of one tailing dam failure occurs every eight months
(39% of which are in the U.S.).
Recent large tailings dam failures
have brought international attention to the issue. Earlier this year, the Mt. Polley Expert Review Panel released recommendations as part of their report on the failure of Mount Polley mine's containment dam in British Columbia. (In 2014 this dam released 14.5 million cubic meters of contaminated water and fine sand
into surrounding rivers.) The panel's recommendations
included shifting industrial priorities from economics to safety, establishing external independent tailings dam review boards to guide the process, and increasing corporate design responsibilities. It should be noted that these are merely recommendations, not requirements.
Last month, our Clean Water and Mining Coordinator, Julia, attended the Alaska Miners Association Convention, as well as the Western Mining Action Network Conference. At both, the failures and risks of mine tailings containment were discussed in length. Additionally, the International Council on Mining and Metals is in the process of conducting a tailings management review, the results of which will come out next week. The EPA is working to address the financial responsibility component (see Cercla 108(b)
), and agencies are working on the nitty-gritty of compensatory mitigation. Currently, there is a greater interest in dry stack tailings which travel only about a mile, as opposed to wet, which are capable of traveling hundreds of miles if released.
At this point, there is much discussion, but little change. However, acknowledgement of the risks and potential failures of tailings containment is a step closer to working together as a greater community to address the dangers of mines and their waste in both existing and proposed mines in Alaska.