By Jack Caldwell - Mining Engineer - Robertson GeoConsultants

Mike Davies is the pre-eminent tailings engineer of present times. He and his team in Vancouver can solve any tailings challenge your mine may face. He and his team at AMEC are the best of the best. They have not paid me to say this; I write, as always, on the basis of personal opinion & conviction.

Here is a link to a paper Mike wrote more than twelve years ago. This paper is still madly relevant; in fact, more relevant now than when it was written a decade and more ago. Here is the introduction to Mike’s paper:

"Are tailings impoundments the most challenging facilities that geotechnical engineers will encounter during their careers? Whether one answers yes or no, there can be no argument that these facilities are indeed challenging and that there is little room for error in their design and stewardship. Where more room has been sought, failures have been the all too frequent result. Can these failures be avoided?

Many geotechnical practitioners get involved with mine tailings impoundments. These practitioners should make themselves familiar with the extensive and, unfortunately, growing database of mine tailings impoundment failure case histories. Many of the failures in the database have been the direct result of a geotechnical failure mode; failure modes that should be less common in modern geotechnical practice. The implications to geotechnical design practice from the trends indicated by the database are clear."

Unfortunately in the years since publication of this paper, the list of tailings failures has grown, and there is little evidence that the profession has heeded the advice & calls that Mike makes. This is both sad and unfortunate; and hence we repeat and recall his advice and challenges.

In the paper, Mike challenges engineers to face the fact that tailings impoundment design & operation are the most difficult of mining challenges. He asks mining folk to tell the honest tales of tailings impoundment failures and learn from these failures.

Mike concludes his paper with this plea that is still relevant to tailings and even more relevant to deaths in the mining industry:

"Consider the following Tailings Dam Failure Axiom – Tailings dam failures are a result of design, construction and/or operational management flaws – not “acts of god”. As a positive corollary to the axiom, if the reasons for tailings dam failures are readily identifiable, there is the potential to essentially eliminate such events with an industry-wide commitment to correct design and stewardship practices. The necessary knowledge for such a scenario exists; the knowledge just has to be used. From the design perspective, the impoundments have, and continue to, speak to us. Are we listening?"

We must listen. We have no alternative. For if impoundments fail, the industry gets a black face, and it becomes progressively more difficult to open new mines and continue cost-effective operation of existing mines.

Thus my recommendations:

  • Read and implement Mike’s paper — it is the best and most succinct statement of the issues ever.
  • Write about failures you know of–your writing may not bring glory, but it will teach us all and hence advance the cause of mining.
  • Design & operate well with the best you can gather — in-house experts, consultants, peer reviewers, implementation of standard practice guidelines, all and all again. And the assignment of individual responsiblity to the folk in the field who ultimately know and understand more than we in Vancouver do.