Alarming pollution findings at Australia's largest gold mine threaten expansion plans

That's the verdict of a recent independent air quality audit at Cadia Valley Operations.

Plans to expand the facility - which is an important employment hub for the region - have been put on hold, and two government departments are investigating.

The 2022 audit found 'solid particulate' emissions from the Cadia crusher vent were 18 times higher than permitted, creating a ploom "clearly" visible from two kilometres away.

Airborne particulates can lead to cardiovascular or respiratory disease, cancer, and other serious health complications, according to NSW government advice.

Cadia had planned to expand its operations this year, increasing output from 32 million tonnes per annum to 35 million tonnes.

The proposal was provisionally approved by the NSW Department of Planning and Environment, subject to the results of and independent air quality audit.

Zephyr was contracted by Cadia parent company Newcrest to conduct the investigation. It was published in October with two non-compliance findings, and approval was revoked.

"[We are] investigating the matters raised in the independent audit report, in collaboration with the NSW Environmental Protection Agency," a spokesperson for the department said.

It's unclear how significant the ongoing health risk is for Orange residents, or if the expansion plans are likely to go ahead on the future.

The Central Western Daily contacted Cadia for further information but did not receive a response before publishing.

Cadia Valley Operations has had ongoing problems with dust and other air pollutants since the collapse of a tailings dam wall in 2018.

Since that time, the facility has been hit with the EPAs maximum fine of $15,000 three times following pollution complaints from nearby residents.

In July this year a vent collapsed at the mine after an underground aquifer was breached, flooding the shaft with at least 160 metres of water and triggering a mass evacuation.

It's unclear if this was the same "crusher" vent allegedly responsible for recent particulate pollution.

A multi-million dollar excavator is believed to have been submerged during the incident.

Cadia Valley Operations is the largest gold mine in Australia, and one of the most important employers in NSW's Central West region.

The full 2022 Zephyr Environmental Independent Air Quality Audit can be found by clicking here.

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