Abstract

The continuous and increasing need for minerals and metals has resulted in gradual declines in the average ore grade of many mineral commodities. Technological improvements have allowed previously uneconomic low-grade, complex deposits to become economically feasible. However, the improved accessibility of large, low-grade deposits often accompanies social-environmental trade-offs. From a mine waste (tailings) perspective, elevated throughput resulting in increased tailings production per tonne of mined product will likely lead to larger Tailings Storage Facilities (TSFs) and, potentially, higher associated downstream risks in the event of a failure. Due to the increasing tailings generation and associated consequences, TSF governance, management, and standards must go beyond purely technical deliverables for maintenance. While the annual failure rate and frequency of tailings storage facility failures is a contentious issue, the consequences of TSF failures and public awareness of the hazards have increased over the last decade.

Currently, consequence and risk assessments of potential TSF failures through dam breach inundation studies are conducted at the local and site level. The work to publicly disclose location and data on TSFs globally by the Global Tailings Review and Global Tailings Disclosure (GTD) allows for a perspective shift, moving from only a local scale understanding of consequences to also include a regional scale understanding. This shift in perspective has highlighted issues of concern with important implications for overall tailings management and governance. However, there is still a missing paradigm in tailings disaster disclosure and analysis, which lies at the country level. Furthermore, research on the impacts of potential TSF failures has been confined to relatively limited sets of impacts and locations.

To address this missing paradigm in tailings consequence understanding, we simulate potential TSF failure scenarios from 248 mines across five countries (Australia, Canada, Chile, Brazil, and South Africa) by using a semi-empirical, Geographic Information System-based tailings flow inundation model (Laharz-T) and publicly available information from the GTD. We conduct a comparative analysis between the five countries of the consequences of potential TSF failures to populations, waterbodies and protected areas while considering the facility raise type and mine status. To the best of the authors' knowledge, this is the first such country-level comparative analysis of the impacts of potential TSF failures. Preliminary results suggest a strong statistical relationship between the country and the frequency and degree of impact on human populations downstream of the sample of mine facilities. The results garnered from this study can be used as a high-level guide for policymakers to better understand the potential consequences of TSF failures and may inform the development of policy intervention targeting high-impact zones that may be more at risk and, thereby, ultimately build towards more robust tailings management.