98
7 Let’s Start with Some Serious “Do Nots”!
3. It impacts areas beyond the acceptable inundation line?
The Canadian Cyanide Code (ICMI 2018), for example, has been effective, by
requiring its members to adopt treatment to reduce cyanide levels within the pond
in order to reduce bird mortality and, more importantly, to reduce the practice of
ignoring freeboard limits for the purpose of meeting contaminant discharge limits.
Thus it indirectly reduces the likelihood of cascading and multiple cause events. In
any event, criteria for success have to be established for the mill operation including
contaminant controls.
The failure criteria and performance criteria are linked. Failure stems out of performances not being attained. It is a combination of them made with “AND” and
“OR” statements. The probability of the failure criteria to occur is the failure of the
system p f with consequences C evaluated by combining the various dimensions of
C. The risk assessment’s dimensions are, by definition, the dimensions of C.
The idea that “Processes are in place to recognize and respond to impending
failure of TSFs and mitigate the potential impacts arising from a potentially catastrophic failure” (ICMM Position 2016) obviously requires clear identification and
communication of success criteria and their opposite: the failure criteria.
Because consequences are multidimensional, the performance of the tailings system should encompass all of them. Thus the successful performance of a tailings
systems could be declared, for example, if:
• water in the pond will be constantly maintained at least at x m from the dam;
• Seepage of certain characteristics is no larger than Q m
3 /yr;
• Discharge through a weir of water with certain characteristics does not exceed q
m
3 /event and v m
3 /yr;
• Loss of tailings through breach, pipelines’ failures, etc. will not exceed k m
3 /event
and runout will not …………and ………;
• etc.
The points above constitute an example of success criteria for the system once all
the missing parameters x, Q, q, v etc. are defined. A successful system is one that can
be considered “unfailed” based on all the assumptions and conditions used through
its evaluation.
The success/failure criteria are also necessary to ensure “Internal and external
review and assurance processes are in place so that controls for TSF risks can be
comprehensively assessed and continually improved (https://www.riskope.com/
2013/11/07/social-acceptability-criteria-winning-back-public-trust-require-drasticoverhaul-of-risk-assessments-common-practice/)”.
It is important to distinguish between the performance criteria (of a project, operation,
company) and the success/failure criteria to be used in the risk assessment. The latter
are “observer-dependent”.
7 Let’s Start with Some Serious “Do Nots”!
3. It impacts areas beyond the acceptable inundation line?
The Canadian Cyanide Code (ICMI 2018), for example, has been effective, by
requiring its members to adopt treatment to reduce cyanide levels within the pond
in order to reduce bird mortality and, more importantly, to reduce the practice of
ignoring freeboard limits for the purpose of meeting contaminant discharge limits.
Thus it indirectly reduces the likelihood of cascading and multiple cause events. In
any event, criteria for success have to be established for the mill operation including
contaminant controls.
The failure criteria and performance criteria are linked. Failure stems out of performances not being attained. It is a combination of them made with “AND” and
“OR” statements. The probability of the failure criteria to occur is the failure of the
system p f with consequences C evaluated by combining the various dimensions of
C. The risk assessment’s dimensions are, by definition, the dimensions of C.
The idea that “Processes are in place to recognize and respond to impending
failure of TSFs and mitigate the potential impacts arising from a potentially catastrophic failure” (ICMM Position 2016) obviously requires clear identification and
communication of success criteria and their opposite: the failure criteria.
Because consequences are multidimensional, the performance of the tailings system should encompass all of them. Thus the successful performance of a tailings
systems could be declared, for example, if:
• water in the pond will be constantly maintained at least at x m from the dam;
• Seepage of certain characteristics is no larger than Q m
3 /yr;
• Discharge through a weir of water with certain characteristics does not exceed q
m
3 /event and v m
3 /yr;
• Loss of tailings through breach, pipelines’ failures, etc. will not exceed k m
3 /event
and runout will not …………and ………;
• etc.
The points above constitute an example of success criteria for the system once all
the missing parameters x, Q, q, v etc. are defined. A successful system is one that can
be considered “unfailed” based on all the assumptions and conditions used through
its evaluation.
The success/failure criteria are also necessary to ensure “Internal and external
review and assurance processes are in place so that controls for TSF risks can be
comprehensively assessed and continually improved (https://www.riskope.com/
2013/11/07/social-acceptability-criteria-winning-back-public-trust-require-drasticoverhaul-of-risk-assessments-common-practice/)”.
It is important to distinguish between the performance criteria (of a project, operation,
company) and the success/failure criteria to be used in the risk assessment. The latter
are “observer-dependent”.