The area of tailings dam failure between the North pond (back) and South pond (foreground) is circled in red. (Image: Newcrest Mining)
NEW SOUTH WALES – Once of Australia’s largest gold mining operations has been shut down following a tailings dam breach on Friday, March 9. The Cadia Valley operations of Newcrest Mining 25 km from the town of Orange.
The tailings problem began when the dam between the North and South ponds slumped after cracks were noted in the area earlier in the day. The breakthrough has been contained in the South pond that is adjacent to but at a lower elevation than the North pond.
Newcrest said there were no injuries, and no environmental changes have been observed outside the tailings management area. The required regulators were immediately informed. The area around the dam has been secured and a geotechnical monitoring system is in place. No further movement of the dam has been seen since Friday night.
As a precaution, the company stopped depositing tailings into both dams on Friday. All mining and milling operations Cadia were suspended the following day. Newcrest noted that and its ore does not contain arsenic, nor does it use mercury or cyanide in its mills.
Newcrest has begun looking at recovery scenarios including alternative tailings locations such as the old Cadia open pit where a prefeasibility study of tailings disposal was already underway.
For the year ending June 30, 2017, the Cadia project produced 619,606 oz. of gold and 63,805 tonnes of copper.
Last month Newcrest took a 27% equity position in Vancouver’s Lundin Gold. Please visit www.Newcrest.com.au.