An underground incident in one of Australia’s largest gold mines has forced the evacuation of staff and extraction to be suspended.
- Extraction at one of Australia’s biggest gold mines has been suspended due to an underground incident
- Cadia Mine was evacuated after instability was detected in a ventilation shaft
- A road bordering the mine has been temporarily shut for safety reasons
Cadia Gold Mine near Orange in the central west of New South Wales has not mined any ore for almost two weeks after it halted underground work on July 22.
Its surface operations, which involve the production of gold and copper concentrate, are still operating and it says it still delivering the same volume of product as usual.
General manager Aaron Brannigan released a statement after the mine was evacuated that said the decision was made to ensure the health and safety of its workforce.
“The evacuation was due to instability in one of Cadia’s vent rises [ventilation shafts],” Mr Brannigan said.
“All personnel were unarmed and many are continuing work in other areas of the operation.”
The Environment Protection Authority and NSW Resources Regulator have confirmed water from an intersecting aquifer has flowed into the ventilation tunnel.
The Natural Resources Access Regulator said it was also investigating the incident.
Cadia confirmed it was carrying out visual assessments.
“We have limited access to the vent rise [and] we will complete our visual inspections through remote techniques and technologies as soon as it is safe to do so,” a statement said.
Damage closes road
The damage underground has also now forced the partial closure of a road bordering the mine.
Cadia Road between Panuara and Woodville roads has been shut and it was not yet known when it would reopen.
The mine is owned by Newcrest Mining, which hosted a community meeting on Tuesday night.
Local farmer Gemma Green said she had not realized how close the ventilation shaft was to Cadia Road.
“It’s actually closer than I thought, it’s about 35 to 45 meters from that main public road,” Ms Green said.
“I would not have that road open after what I heard last night.
“The instability in that top 100 meters that was shared and the potential crumbling of what they call the collar.
“My biggest concern is emergency services route, in the event that someone has to call an ambulance.”
Gemma Green chairs the Cadia Community and Sustainability Group and said one if its key issues was the protection of local water sources.
“The damage is obviously very serious and one of their key intentions is to stop that water flowing into the ventilation shaft,” she said.
“Newcrest made it very clear that their intention is to stop the water as quickly and safely as they can.
“I’d be encouraging people to give their feedback locally in and around that aquifer in the event they have changes in their bore levels.”
In a statement on Wednesday Cadia’s general manager Aaron Brannigan said the proposed response plan would be carried out in a series of steps.
“The initial assessment of the area directly surrounding the ventilation [shaft] to ensure it is safe to access, the mobilization of drill rigs to install a high-pressure grout curtain to minimize the water inflow and filling the vent with inert rock material to stabilize it,” the statement said.