Last week I was in Banff, Alberta at the 2009 Conference on Tailings and Mine Waste. In time they promise to post on their site the PowerPoint presentations. One that is worth summarizing now is by AMEC engineers, Michael Davies and Todd Martin, both well respected and knowledgeable folk.

They write:

"Tailings dam incidents, namely physical failures and major operational upsets, have been described in the literature for over 30 years. These accounts typically address the contributing physical attributes and/or design/operational deficiencies that led in whole, or in part, to the recorded incident. One aspect of tailings dam stewardship not typically noted let alone evaluated in terms of contribution to incidents of record are the prevailing economic conditions during a key period of design, construction and/or operation. An evaluation of the temporal trends in tailings dam incidents relative to the cyclical nature of the economic realities of the mining industry is examined in this paper. Although clearly no perfect correlation exists, there appears some validity to the hypothesis that the frequency of tailings dams incidents can be expected to increase some relatively short period after a cyclic boom in mining industry."

In other words, if there is a mining boom like we had last year and some while preceding that, soon enough there will be a failure of a tailings dam. In that the lag time is about one to two years, we should be expecting a major tailings dam incident any day now. If they are correct, that is.

I cannot quite come to believe their correlation theories. However, they provide some plausible reason why the dam could fail after the economic boom:

  1. Permit haste
  2. Fast track investigation,design, and construction
  3. Cost cutting after the boom
  4. Inexperienced but overconfident designers
  5. Lack of independent third party peer review
  6. Rapid turnover of mine personnel
  7. Disconnect between design expectations and operational reality
  8. Development of deposits that have been left undeveloped for good reason
  9. “Cookie cutter” designs.

I am persuaded that these factors can and often do lead to a tailings dam failure. So regardless of the economic times, make sure you avoid them in the design, construction, and operation of your tailings impoundment.