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SAFETY AND HEALTH ALERTS AND GUIDANCE
TAILING STORAGE FACILITIES Tailings are by-products of processed ore minerals. Depending on the type of ore and the method of processing, tailings could contain toxic and environmentally harmful substances or could be totally benign. Tailings are stored in different types of tailings storage facilities (TSFs), with the most common TSFs having embankments to contain the tailings. Mined-out open pits are also used as TSFs with no
containment embankments. Tailings are also stored within mine waste rock dumps. Regardless of being toxic or benign, sudden release of tailings could cause significant safety, health and environmental hazards. Such incidents could occur if the TSF embankments are not designed, constructed, operated and closed to comply with acceptable standards. In other countries, several catastrophic failures of TSF embankments have occurred and have destroyed lives, property and the environment.
TSFS IN WESTERN AUSTRALIA There are about 500 TSFs in Western Australia, with the majority located on relatively flat ground in low rainfall regions of the State. The flat topographic and dry climatic conditions reduce the potential for sudden failures of TSFs.
TSF with an embankment
Nonetheless, minor failures in the form of embankment erosion and overtopping (where material flows over the embankment) have occurred without causing much damage. To reduce the risk of TSF failure, a stringent regulatory process is followed in Western Australia. The process includes:
In-pit TSF with no embankment
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• thorough scrutiny of the design proposals for any new TSFs and any changes to existing TSFs, before granting approval for construction • enforcement of the construction quality control measures to ensure compliance with the approved design and relevant standards • mandatory twice daily inspection, plus ongoing maintenance and record keeping by nominated mine site personnel during TSF operation • mandatory periodic review and audit of the TSF performance by third party experts
