A standard for design life and durability for engineered mine wastes structures

Abstract

Within Australia, and arguably more widely, there is a dearth of mine site rehabilitation that has been validated as successful against agreed objectives and targets. One reason for this is the absence of accepted design life and durability standards, applied during the planning and design of major mine wastes landforms such as tailings storage facilities and waste rock dumps, against which performance can be assessed. The themes of design life and durability have been applied in other engineering disciplines such as construction, manufacturing, and transport infrastructure. Therefore, the template exists; albeit its application to mine wastes landforms is more complex, given the uniqueness of each mine site and the materials available for landform construction. Given the poor rehabilitation performance of the industry to date, an increasingly informed and sceptical public may no longer accept assurances that structures will be risk free for periods of 1000 years or more. In view of this, the industry and the regulator must present realistic expectations and be clear about, and have mechanisms in place to manage, residual risks. This paper aims to address this question and provides a framework around which standards that account for different levels of risk can be developed for design life and durability for engineered mine wastes structures.