Wall of tailings dam at the Cadia mine, about 20km south of Orange, collapsed after two earthquakes

This article is more than 2 years old

This article is more than 2 years old

A New South Wales goldmine forced to shut down for three months last year after an earthquake has again halted operations following a dam wall breach.

The wall of a tailings dam at the Cadia mine, about 20km south of Orange, partially collapsed on Friday after there were two magnitude 2.7 earthquakes in the region on Thursday.

Its operator, Newcrest Mining, says there is no threat to personal safety and it has secured the area around the dam.

A “comprehensive geotechnical monitoring system” was implemented, the company has said.

The material involved, which was contained within the southern dam, was described as “a slurry of finely ground rock, water and a low level of benign processing re-agents”.

The mine was forced to shut down after it was hit by a magnitude 4.3 earthquake in April 2017 and did not return to partial production until July, causing a huge hit to the company’s first-half profit.

Newcrest said the dams had also been regularly inspected, reviewed and monitored.

“Safety is our highest priority,” it said. “We have secured the area around the tailings dam, and have implemented a comprehensive geotechnical monitoring system.”

NSW regulators were notified and the Environment Protection Authority said it was inspecting.

“NSW EPA understand the tailing has been contained,” a spokeswoman said.

Geoscience Australia recorded the two earthquakes as occurring southwest of Cadia on Thursday at a depth of 10km and magnitude 2.7.

Cadia is Newcrest’s biggest and lowest-cost mine.





