A comment to a blogpost on tailings failures inspired this comment on the eternal confusion between tailings hazard and risks.
Indeed, we think those arguments are misleading and not helping the cause of tailings risk reduction. Let’s discuss.
The True Number of Tailings Dams on the Planet
The tonnage of tailings and by-products of the mining industry ejected into the environment is staggering.
Giant Mine in Northwest Territories, Canada, is an egregious example of mining by-products creating hazardous conditions. There is a large volume of arsenic trioxide stored underground in manmade caverns. These were formerly entirely in permafrost. The risk to population and waterbodies has justified a project to contain the underground stored materials in perpetuity.
The number of tailings dams on the planet remains unknown despite actuarial efforts to date. Regardless, knowing the number of dams is not enough to help solving the right problems in the right place. We would need to be able to class the number of dams by size, type of mining activities, age, deposition activity and other parameters, such as potential consequences. Then we would be able to meaningfully talk about the “world portfolio” risk.
The Eternal Confusion Between Tailings Hazard and Risks
We have pointed out when discussing statistics and runout approaches that it is misleading to take undifferentiated data and lump them together to obtain generalized rules. An analyst should always clearly define types of failures, consequences and probabilities (or rates if one looks backwards) of those failures. One should separate data into meaningful populations. When discussing tailings, one should use the term “risk” to make better decisions, not to deliver sensationalist news. In the past, we have focused our attention on very large failures and looking at large dams capable of generating those failures only. Spending time and effort on minor failures or failures with little overall consequences, likely generating low risks, will not help with worldwide tailings management.
Closing Remarks
The worldwide tailings dam risk is not proportional to the number of dams. A larger dam does not necessarily mean a larger risk. We have to be much more sophisticated in our judgement and decision-making. Lumping up all dams to draw one-size-fits-all conclusions is wrong and misleading.
Claiming a larger number of tailings dams as the cause of catastrophic outcome does not ensure the attention of governments and decision-makers. On the contrary, it will likely lead us to squander time, energy and mitigative capital.
We think the high rate of catastrophic failures in the last decade has triggered pertinent reactions worldwide. However, in order to maintain the motivation, we need to be rational and avoid sensationalism. Codes must propose well-balanced rules and foster risk-informed analyses.
Thus, unless we use the word “risk” properly, misinformation and confusion will arise instead of better dam performances. We need to solve the eternal confusion between tailings hazard and risks. Education and rational analyses leading to unbiased prioritization are a must.
Now it is time to engineer a better future, and to communicate risk in the most rational and dispassionate way.
