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includes another seventy-five dams that are too The “Guidelines for Cooperation with the Update on Mine small to meet the regulatory definition of a dam Alaska Dam Safety Program” provide a detailed based on either state or federal criteria. overview of the program. The Alaska dam safe- Dam Several dams at mines are subject to regula- ty regulations are flexible and generic in order tion by ADNR Dam Safety. Both the Red Dog to address a wide variety of projects, from small, Regulation Mine and the Fort Knox Mine utilize large, supply dams for villages to the large, tail- rockfill embankment dams to store tailings. A ings dams at mines. The Alaska dam safety in Alaska and relatively small, rockfill dam impounds tailings regulations also include requirements that are at the Kensington Mine. A small embankment unique for mine tailings dams in closure. dam stores tailings from previous operations at the Nixon Fork Mine. The Greens Creek Mine, The National and International the Pogo Mine, and the current operations at the Mission Towards Safe Dams By Charles F. Cobb, PE Nixon Fork Mine (underground mines) utilize a The Buffalo Creek Mine failed tailings management method referred to as “dry in 1972, killing 125 people, and led to the Na- he contributions of to human stacking” for tailings disposed above ground. tional Dam Inspection Act of 1972 and the advancement are taken for granted Greens Creek, Kensington, and Pogo also back- first compilation of the NID. This tragedy when people take off in their cars, talk fill mined out stopes with tailings. Water reten- raised the level of attention to the safety of Ton their cell phones, watch the television, cook tion dams help manage storm and contact water dams in the and the world and on their stoves, and many other ordinary and at these mines, and water retention dams are uti- set the stage for the advent of the national extraordinary activities. Elements from the lized at Fort Knox and Red Dog Mines for fresh- and state dam safety programs that followed earth make our lives comfortable, healthy, and . A small at Red Dog the various enabling legislation. safe, but the investment in people, equipment, is also regulated, and the heap leach pad at Fort In 1976, the Resource Conservation and Re- and necessary to produce those Knox is regulated as a dam, even though there covery Act addressed the management of haz- elements in a safe, responsible way is often is no open water pond behind the rockfill em- ardous and solid wastes. However, for various overlooked. Dams at mines are an important bankment dam that stabilizes the heap. reasons including the broad regional diversity part of the infrastructure contributing to the All of the dams at the hard mines in of mining, geology, and , the Solid well-being of society that are not overlooked. Alaska have current periodic safety inspection Waste Amendment Act of 1980 included the The Alaska Dam Safety Program in the reports, appear to be in satisfactory condition, Bevill Amendment which provided an exemp- Alaska Department of Natural Resources and are in general compliance with the Alaska tion for certain mine wastes including tailings, (ADNR) is responsible for ensuring the safety dam safety regulations including emergency ac- resulting in exclusive state authority for regu- of dams at mines in Alaska, similar to other tion plans. Satisfactory condition is the highest lating mine tailings dams (with some excep- state and provincial regulatory programs rating in a system developed by the US Corps tions such as coal and uranium tailings). across the United States and . The fol- of Engineers for dams on the NID and means The State of Alaska demonstrated leader- lowing information presents a brief review of that a dam is expected to demonstrate accept- ship in dam safety with passage of the Alaska the Alaska Dam Safety Program, the purposes able performance under all loading conditions Water Use Act of 1966 (AS 46.15). In the early of dams at mines in Alaska, and a broad over- including extreme and . 1980s, the Alaska Dam Safety Program was view of the response in North Amer- organized by ADNR under Chapter 93 of Ti- ica to tailings dam failures at mines, from Protecting Downstream tle 11 of the Alaska Administrative Code (11 the Buffalo Creek Mine tailings Communities and Resources AAC 93). The subsequent Alaska Dam Safety in West in 1972 to the tailings dam The primary objective of ADNR Dam Safety is Act of 1987 improved and formalized the leg- failure at the Samarco Mine in in 2015. to protect the downstream communities and islative authority for regulating dams. resources that may be affected by the operation The current dam safety regulations were pro- Protecting Life and Property or failure of a dam. To achieve the mutual goal mulgated in 1989 and revised in 2004. The Alas- The mission of the Alaska Dam Safety Pro- of safe dams, effective and co- ka Dam Safety Program was based on a model gram is to protect life and property in Alaska operative relationships are required between the dam safety program developed in multi-agency through the effective collection, evaluation, various persons, businesses, agencies, and other committees including members of the Associa- understanding, and sharing of the informa- interests that are involved in the permitting, de- tion of State Dam Safety Officials (ASDSO) and tion necessary to identify, estimate, and miti- sign, construction, and operation of dams. the Federal Emergency Management Agency gate the risks created by dams. The Dam Safe- ADNR Dam Safety receives geotechnical (FEMA), the administrator of the National Dam ty and Construction Unit (Dam Safety) within investigation reports, design drawings, engi- Safety Program. While FEMA’s role is primarily the Section of the Division of neering evaluations, detailed design reports, to develop and promote consistent standards, as Mining, Land and Water of ADNR admin- construction specifications, quality assur- well as to support and strengthen state programs, isters the program under the authority of ance plans, emergency action plans, periodic the states retain the authority for ensuring the Alaska Statute 46.17 to “supervise the safety” safety inspection reports, and more. The level safety of 80 percent of the nation’s 84,000 dams. of dams under state regulatory jurisdiction. of detail in this information is dependent on ASDSO is an organization of state dam safe- This includes a variety of dams, from small, the size, complexity, hazard potential classi- ty officials with over three thousand members dams for the of villages fication, and risk of the dam. at large that develops and disseminates infor- to large, rockfill embankment dams used for Much of the work represents multi-million- mation to promote the safe design, construc- tailings storage at hard rock mines in Alaska. dollar construction projects and requires highly tion, and operation of the majority of the dams The Alaska Dam Inventory includes seventy- specialized engineers for the technical design in the United States. In Canada, dams are six dams under state regulatory authority. The and analyses. Independent inspections and en- regulated at the provincial and territorial level, National Inventory of Dams (NID) lists twen- gineering evaluations are conducted by ADNR and the Canadian Dam Association serves a ty-five dams in Alaska under federal authority. Dam Safety as necessary to confirm and moni- similar role as ASDSO and part of FEMA’s. Federally owned and operated dams and dams tor the condition and safety of the dam. After In August 2014, a large tailings dam failed regulated by the Federal Energy Regulatory detailed technical reviews are completed on en- at the Mount Polley Mine in British Columbia. Commission (i.e., most hydroelectric dams in gineering submittals, ADNR Dam Safety issues While the failure was spectacular, there were Alaska) are exempt by statute from state dam a Certificate of Approval to Construct, Repair, no human casualties and the environmental safety authority to preclude redundant regula- Modify, Operate, Remove, or Abandon a Dam impacts were apparently not as severe as many tory oversight. The Alaska Dam Inventory also to indicate compliance with program objectives. feared. In November 2015, a large tailings dam

34 Alaska Business Monthly | January 2017 www.akbizmag.com failed at the Samarco Mine in Brazil. In con- Denver, to discuss the responsibili- dialogue with ADNR Dam Safety. With the help trast, nineteen lives were lost, two villages were ties of tailings dam engineers in the United of the community, dam owners and destroyed, and the outflow from the impound- States. Many other organizations are work- operators, state and federal agencies, and many ment affected the turbidity in the Atlantic Ocean ing on various related projects also. others, as well as the appropriate resources for all more than four hundred miles downstream. Accurate understanding and effective com- involved to do the necessary work, ADNR Dam These incidents increased the attention on munication of technical and operational re- Safety will continue to help bear the standard for tailings dams at mines around the world and quirements are paramount to ensuring that all safe tailings dams in Alaska and the nation. caused mining companies, regulatory agen- dams are safe including mine tailings dams. The For more information on the Alaska Dam cies, and engineering businesses to take a recent tailings dam failures increased awareness Safety Program, visit dnr.alaska.gov/mlw/ fresh look at policies, regulations, and busi- of the importance of safe tailings dams at an in- water/dams or contact ADNR Dam Safety at ness practices. For example, after the Mount ternational level. ADNR Dam Safety reviewed (907) 269-8636. Visit ASDSO at damsafety. Polley incident, the Mining Association of the reports on the technical investigations of org and USSD at ussdams.org. R Canada reviewed their membership proto- these incidents and is reviewing the current state col “Towards Sustainable Mining” and pub- regulations for opportunities for improvement. Charles F. Cobb, PE is the State Dam lished the “Report of the TSM Task Force: In the meantime, all of the existing dams at Safety Engineer for the State of Alaska Recommendations to Strengthen the Mining hard rock mines in Alaska appear to be safe and Department of Natural Resources. Association of Canada’s Tailings Manage- the mining companies are actively engaged in ment Requirements and Guidance” (2015). Dam safety regulations applicable to mining across Canada are under review by respective agencies. In direct response to the investigation of the Mount Polley failure, the Association of Professional Engineers and Geoscientists of British Columbia published “Professional Prac- tice Guidelines: Site Characterization for Dam Foundations in BC” (2016) which includes specific requirements for site investigations for dams, as well as guidelines on the responsibili- ties for the engineers involved with designing and operating dams at mines. In the United States, the Mining Association promoted significant revisions to the mining statutes which were adopted and promulgated by the State of Montana in 2015. The Tailings Dam Committee of the United States Society of Dams (USSD) held a workshop on tailings dams after mine clo- sure at their 2015 annual conference. In 2016, ASDSO formed a Tailings Dam Regulatory Workgroup led by the writer to de- velop an issue paper for the board of directors. This effort resulted in a resolution on tailings dam safety that was passed unanimously by the state representatives at the annual busi- ness meeting. The resolution directs the orga- nization to support state dam safety programs with regulatory authority over tailings dams. The workgroup conducted a survey of states and determined that 947 tailings dams listed on the NID are distributed across thirty-nine states, of which twenty-five state dam safety programs have jurisdiction over tailings dams, while several other states regulate tailings dams under other state programs. The workgroup also recommended the formalization of a Tail- ings Dam Regulatory Committee, in contrast to the technical committee sponsored by USSD, although there are many common interests. The purposes recommended for this commit- tee include assessing relevant information from organizations such as the International Com- mission on Large Dams and disseminating that information to the state dam safety programs that regulate tailings dams. In addition, the committee can facilitate a dialogue between the multitude of stakeholders in mine tailings man- agement in order to advance common interests. (The ASDSO board is meeting to discuss the for- mation of the committee and the publication of the issue paper as this article goes to press.) In January 2017, the Geoprofessional Busi- ness Association is holding a workshop in www.akbizmag.com January 2017 | Alaska Business Monthly 35