Tailings dams : design criteria and safety evaluations at closure

The majority of currently available dam safety guidelines do not account well for the specifics of tailings dams. In the guidelines commonly used in Canada, tailings dams are addressed alongside water retention (conventional) dams. This results in an user-unfriendly, and potentially unsafe and/or inappropriate, treatment of safety aspects specific to tailings dams. A number of guidelines developed for tailings dams have been published by the International Commission on Large Dams (ICOLD). Except for one of those guidelines (ICOLD 1989), a focus on the tailings dam safety is not provided. In particular, there seem to be very few and largely incomplete guidelines that speak to dam safety aspects specific to the tailings dam closure phase. Unlike for a conventional dam that would typically be breached upon the end of its useful life, the closure phase will be by far the longest state of being for a tailings dam, regardless of how long the dam was in operational use. This paper identifies and examines a number of tailings dam design criteria and safety requirements applicable to the closure phase, and concludes that many of such requirements must currently be selected on a case-by-case basis without support of sufficiently comprehensive guidelines.Non UBCUnreviewedOthe