Abstract
Effective and safe management of tailings storage facilities (TSFs) is a key topic of discussion in the mining industry today. While current efforts focus mainly on new studies, designs, construction, and operation of TSFs, it is equality critical that effective stewardship continues in the final life stages including closure and post-closure. There is a strong drive on the part of many mining companies across the world on quality and safe TSF management, and a lot of interest from investors, communities, and other external stakeholders in preventing catastrophic TSF failures.
This paper discusses the need for solid and well thought governance processes to be implemented for all TSFs that go into care and maintenance (C&M), become inactive, and eventually move into a closure and post-closure stage. Recent dam failures in the mining industry highlighted that inactive or partly closed facilities are not immune to catastrophic failure mechanisms. Even safely closed TSFs can have a risk profile that needs management and mitigation.
The authors elaborate on several leading practices that could be considered for implementation, considering the requirements of Global Industry Standard on Tailings Management, the ICMM Good practice Guide on Tailings Management, the recently published SME Tailings Management Handbook, as well as the Draft ICOLD Bulletin on Tailings Dam Safety. Such good practice guidance is blended in this presentation with several examples of current implementation at various mines around the world. The paper discusses key Governance practices, and dedicated OMS manuals reflective of the TSF status, but also the management of risks in closure and post-closure to meet company and stakeholder expectations. The roles of Accountable Executive (AE), Responsible Tailings Facility Engineer (RTFE), Engineer of record (EOR) and Independent Tailings Review Board (ITRB) take a slightly different meaning and the array of responsibilities changes over time, reflecting the TSF condition.
The statement made by the authors in this paper reflects the factual aspect that risk is never zero for surface TSFs, even though we’d like to believe so. Simply because a TSF is safely closed, it does not mean that a “do nothing” approach is acceptable. While a closed condition may seem to reflect a lower risk profile for a TSF, several minimum requirements need to be met in order to ensure long term stable structures. Several “what if” scenarios are discussed, highlighting cases where TSF performance may not go according to plan, and where risks need to me mitigated for unforeseen situations far into the future.