Responsible management of tailings is an important focus of MAC and its members. Tailings are an unavoidable by-product of mining, consisting of the processed rock or soil left over from the separation of the commodities of value from the rock or soil within which they occur. If not managed responsibly, tailings can pose potential risks to human health and safety, the environment, infrastructure, and to mining companies themselves. Responsible tailings management is essential to minimizing and mitigating these risks.
MAC has played a leading role in tailings management for more than two decades and has developed two guidance documents that can be applied to any tailings facility in the world.
A Guide to the Management of Tailings Facilities (the Tailings Guide) provides guidance for the development and implementation of site-specific tailings management systems. The Tailings Guide was first released in 1998, with its second and third editions released in 2011 and 2017 respectively. The newly updated Version 3.1, released in 2019, provides stronger and more detailed guidance for emergency preparedness.
Developing and Operation, Maintenance, and Surveillance Manual for Tailings and Water Management Facilities (the OMS Guide) provides guidance on the development and implementation of site-specific operation, maintenance, and surveillance (OMS) manuals. First released in 2003, the second edition was released in early 2019.
Implemented together, the Tailings Guide and the OMS Guide provide a comprehensive approach to the responsible management of tailings across the entire life cycle of a tailings facility, from the initial planning for tailings management as part of mine planning, through to closure and post-closure.
Review of the Tailings Guide, OMS Guide, and Protocol
Following the 2014 failure of the tailings facility at the Mount Polley Mine in British Columbia, MAC’s Board of Directors initiated a review of the Protocol and Guides to consider whether any improvements could be made so that owners who apply the MAC guidance can have increased confidence in the safety of their tailings facilities. This review consisted of both independent and internal reviews.
The independent review was completed by a seven-member Task Force appointed by MAC’s Board. The final report of the independent review, completed in November 2015, included 29 recommendations, all of which have been acted on, to strengthen MAC’s tailings management guidance and requirements.
The internal review was conducted by the MAC Tailings Working Group (TWG), which consists of more than 50 representatives of MAC’s membership. Collectively, TWG members have a tremendous depth and breadth of experience and expertise in tailings management in Canada and around the world.
The outcome of these reviews was an update and modernization of the Tailings Guide, OMS Guide and the Tailings Management Protocol, reflecting recommendations of the independent and internal reviews, current best practices, and lessons learned from over 20 years of implementation experience since the first edition of the Tailings Guide was released.