Update on Mine Tailings Dam regulation in Alaska and North America.

• Author: Cobb, Charles F.
• Position: MINING

The contributions of mining to human advancement are taken for granted when people take off in their cars, talk on their cell phones, watch the television, cook on their stoves, and many other ordinary and extraordinary activities. Elements from the earth make our lives comfortable, healthy, and safe, but the investment in people, equipment, and infrastructure necessary to produce those elements in a safe, responsible way is often overlooked. Dams at mines are an important part of the infrastructure contributing to the well-being of society that are not overlooked.

The Alaska Dam Safety Program in the Alaska Department of Natural Resources (ADNR) is responsible for ensuring the safety of dams at mines in Alaska, similar to other state and provincial regulatory programs across the United States and Canada. The following information presents a brief review of the Alaska Dam Safety Program, the purposes of dams at mines in Alaska, and a broad overview of the industry response in North America to tailings dam failures at mines, from the Buffalo Creek Mine tailings dam failure in West Virginia in 1972 to the tailings dam failure at the Samarco Mine in Brazil in 2015.

Protecting Life and Property

The mission of the Alaska Dam Safety Program is to protect life and property in Alaska through the effective collection, evaluation, understanding, and sharing of the information necessary to identify, estimate, and mitigate the risks created by dams. The Dam Safety and Construction Unit (Dam Safety) within the Water Resources Section of the Division of Mining, Land and Water of ADNR administers the program under the authority of Alaska Statute 46.17 to "supervise the safety" of dams under state regulatory jurisdiction. This includes a variety of dams, from small, concrete dams for the water supply of villages to large, rockfill embankment dams used for tailings storage at hard rock mines in Alaska.

The Alaska Dam Inventory includes seventy-six dams under state regulatory authority. The National Inventory of Dams (NID) lists twenty-five dams in Alaska under federal authority. Federally owned and operated dams and dams regulated by the Federal Energy Regulatory Commission (i.e., most hydroelectric dams in Alaska) are exempt by statute from state dam safety authority to preclude redundant regulatory oversight. The Alaska Dam Inventory also includes another seventy-five dams that are too small to meet the regulatory definition of a dam based on either state or federal criteria.

Several dams at mines are subject to regulation by ADNR Dam Safety. Both the Red Dog Mine and the Fort Knox Mine utilize large, rockfill embankment dams to store tailings. A relatively small, rockfill dam impounds tailings at...