Managing failure risk for tailing storage facilities
CIM Montreal 2015
Andrew\ Watson (MWH), Resa Furey (MWH)
Risk is sometimes described as the product of consequence and likelihood of occurrence. In dealing with risk associated with every stage of the tailing storage facility (TSF) lifecycle -- design, construction, operation and closure – we are predisposed to deal with the immediate risks, and avoid dealing with the “less likely,” to the point that we might trivialize the consequences of failures that are so rare they are considered statistically insignificant. Yet it is the consequences of infrequent and unplanned events (earthquakes, significant precipitation events, unforeseen challenges) that contribute to the TSF failures that put companies out of business and tarnish the industry reputation. It is within this context that the author will argue
a) that greater emphasis must be placed on addressing the catastrophic rather than the chronic risk of TSF failure.
b) that best practices for risk management associated with tailing facilities come from strong cultures that focus on the judicious use of management tools, processes and procedures.
As we add flood and earthquake data to our records, we update our estimates of the forces of nature that confront us: these are tending to get larger as the period of record is lengthened. Meanwhile, it is prudent to focus less on demonstrating how we can survive what we think is an appropriately conservative estimate of the forces of nature, and expend more effort devising ways in which these structures can accommodate rare events much larger than we have experienced previously without failing catastrophically. This paper explores past failure mechanisms and how these can inform our designs and our management practices going forward.
Risk Management, Tailing management