Reading the ICMM Guidance and Conformance protocols
May 19th, 2021
We started reading the ICMM Guidance and Conformance protocols with great interest and were pleased with a number of specifications we saw. Of course, an endeavor of this magnitude and scope will stir a lot of interest in the mining world.
From our end, given our long experience in tailings system risks, we could not resist to compare the protocols to our day-to-day practice. We noted areas where more detailed explanations would likely benefit the mining industry and the public.
Many of these comments have to do with:
- making the process agile enough to avoid paralysis by analysis,
- further specify the glossary as to avoid biases and misinterpretations and finally
- ensure that GISTM (Global Industry Standard on Tailings Management) conformance is “comparable” across owners, countries and dams portfolios.
Of course the text below is a summary of our reading. Indeed, we have numerous other detail comments that we started presenting when the GISTM was published.
Conflict of interest, ethics and glossary
When Reading the ICMM Guidance and Conformance protocols we were delighted to see sections on conflict of interest, the need for third party as well as a glossary!
Indeed, we consider as paramount:
- the reduction of conflict of interest and biases in the approach to tailings dams risks. As a matter of fact we wrote a paper on this back in 2013. The title was Can We Stop Misrepresenting Reality to the Public;
- giving due consideration to public expectations and ethics. Indeed, Chapter 5 in our 2019 Tailings Management book looks specifically at these aspects. Finally;
- the need for a unified and crystal-clear glossary in risk engineering. As a matter of fact, we are at the third update of the Riskope glossary. The full glossary is freely downloadable, of course.
ALARP, tolerance, and residual risks
In our mind the concept of assessing benefit of mitigation effort, residual risks, ALARP and risk tolerance are closely linked. The ICMM guidance uses the figure (9) below:
We have used a different, but similar figure for many years. We show it below, as it comes out of our Tailings Management book cited above:
In our mind showing the ALARP value as a range and not as a theoretical dot helps conveying the idea that tailings systems are complex and surrounded by uncertainties.
Back to reading the ICMM Guidance and Conformance protocols, it would have been nice if they defined and quantified the term tolerance. Delivering a quantitative risk tolerance threshold is part of our day-to-day practice for mining industry. It brings significant value to tactical and strategic planning of mitigation applied to a portfolio of systems.
Glossary is important and should be robust
Terms like negligible likelihood should also be better explained to avoid blunders and preposterous statements. In addition, more clarity on this term would enhance consistency in the conformance by different companies and different EoRs. Egregious examples of possible confusion and resulting crisis appear on a regular basis in the media. For instance, an assessment of the probability of failure of a hydro dam in the US reportedly delivered a value of 1 in a billion in any given year. How an assessment may have come to that value was not described, but that value is blatantly invalid as it is:
A later assessment of the same US hydro dam reportedly delivered a higher value, 1.5-in-10,000 chance of a dam failure. This last value is in line with “normal hydro dams”; however the jump upward reportedly created a crisis situation. In the present state we think that this type of crisis may arise with tailings dams unless the ICMM documents become more prescriptive and clearer on the objectives, terminology.
Selected ICMM conformance requirements discussion
Risk informed decision making
Requirement 4.7 clearly states the need for risk informed decision making for existing structures. Additionally it requires reaching an ALARP level. To ensure repeatability and transparency we consider this is feasible only with a quantitative risk assessment (QRA) approach. Fortunately, this is one of the two possible means considered by the ICMM document. Indeed, the other alternative, i.e. a semi-quantitative FMEA (see requirement 5.4, note 1) does not offer the same level of resolution, repeatability and transparency. Furthermore, especially for owners of large portfolios, semi-quantitative FMEA would lead to paralysis by analysis, least excessive costs and deter users from regular updates.
Reducing probability and consequences of failures
Requirement 4.7 also asks for approval and documentation of measures to reduce both the probability and the consequences of a tailings facility failure. These actions are aiming at reducing the risk to a level as low as reasonably practicable (ALARP). Conformance will require risk informed basis and timing for addressing the upgrade of existing tailings facilities. In addition, conformance requires to carry out actions as soon as reasonably practical, indicating the need for a risk-based prioritization of these actions.
Using appropriate methods to reach the ICMM goals
As stated above, a FMEA will not provide a granular enough probability of failure and a swift comparison to the ALARP target. This is one of the reasons we developed ORE2 Tailings™. Indeed, ORE2_Tailings™ anticipated the ICMM requirements as it covers these angles and more. For instance it includes the evaluation of the impact of standard of care on a given system. Furthermore, ORE2_Tailings™ delivers the probability of failure of the dam system and benchmarks it to the world-wide tailings dams portfolio performance.
Dam system knowledge base and results completeness
ORE2_Tailings™ accommodates uncertainties generated by possible deficiencies in the knowledge base. ORE2_Tailings™ shows how these afflict the probability of failure allowing to risk-inform knowledge base enhancements, and then prioritized possible mitigations.
Requirement 5.4 states that risk assessments typically use various methods, including Quantitative Risk Assessment (QRA). As stated above, in our experience only a well developed QRA can deliver the right answer and include the dam system. That is the dam and all the ancillary water management, pipelines, diversions, traffic, etc. Indeed ORE2_Tailings™ studies the causality of potential dam systems failures and from there it allows engineers to design out or check pertinent failure modes. A priori causality analysis is not possible with FMEA.
A faster and more incisive approach than classic FTA, ETA, FMEA methods is required especially if the knowledge base is incomplete. In addition the ICMM documents demand for reassessment of any system, if material changes occur. The ORE2_Tailings™ dashboard deliver clear images of the state of a system and of its evolution, including the effects of knowledge base enhancements. ORE2_Tailings™ also covers the requirement 6.5, 1, i.e. a Deviance Accountability Report (DAR). It will become part of the internal/external review of continuous improvements.
Finally, requirement 10 reiterates the need for a systemic view. Again a theme Riskope consider paramount in tailings management. For instance, ORE2_tailings™ deployments always look at internal and external interdependencies. Which is a necessity to mitigate rationally a site and its facilities.
Conclusion from reading the ICMM Guidance and Conformance protocols
Reading the ICMM Guidance and Conformance protocols (ICMM • Conformance Protocols: Global Industry Standard on Tailings Management (2021)) clearly showed that the ambitious ICMM undertaking goes in the right direction. We think that the overall processes are going to be beneficial to the industry, its investors and the public. However, as we stated above, the definition of some terms such as:
- good practice,
- best practice,
- negligible, and finally
- tolerable/ acceptable
would reduce the occurrence of “semi-conformances” and increase the repeatability of the results, thus allowing to compare dams all over the world, for everyone’s benefit.
We reiterate our opinion against the usual rule that bins the consequence of a tailings facility failure based on the most severe among loss categories. This rule is obsolete and goes against experience .
Finally, even the terms “conservative” and “design criteria such as factors of safety” remain open to interpretations unless shored by a quantitative estimate of the corresponding probability of failure.
Tagged with: ALARP, ETA, Ethics, FMEA, FTA, GISTM, glossary, ICMM, residual risks, tolerance
Category: Consequences, Mitigations, Optimum Risk Estimates, ORE2_Tailings, Probabilities, Risk analysis, Risk management, Tolerance/Acceptability