Residents of a small regional community near Orange in New South Wales have filed an environmental class action over a “toxic trifecta” of alleged pollution caused by Cadia goldmine.

The supreme court challenge against Cadia Holdings, which trades as Cadia Valley Operations and is owned by Newmont, is seeking compensation including damages for a reduction in property values and an injunction to restrain further pollution.

Cadia Community Sustainability Network, represented by William Roberts Lawyers, alleges residents near the gold and copper mine have been exposed to “a toxic trifecta of air, land and water pollution emanating from the mine site”.

The legal challenge follows years of concerns raised by community members, and reporting by Guardian Australia, about dust and heavy metal contamination.

Jann Harries is a lead litigant in the proceedings and lives on a property about 3km from the mine.

She said the concerns of residents included dust pollution on their properties, water testing showing heavy metals in ground and surface water and in rain tanks, the impact of dust pollution on livestock, and medical concerns.

“I’ve got heavy metals in my water, in my dams, my water tanks are testing extremely high for heavy metals,” she said.

“We’re getting dust all through our grasses, which is probably affecting our stock.”

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Harries said they “don’t want the mine to close”.

“But we have to live next door to them. They have to be good neighbours to all of us that are living around them.”

The community group’s claim includes allegations that independent testing it commissioned found pollution in creeks and groundwater flowing into the Belubula River at levels that threatened local ecosystems and agriculture. The group believes this stems from contaminants including heavy metals and Pfas from Cadia’s mining operations.

William Roberts’ principal lawyer Oliver Gayner said the community group considered the class action a “last resort”.

“For several years the Cadia residents have repeatedly raised their concerns about the detrimental environmental impact caused by this mine,” he said.

“They have provided scientific evidence to Newmont and the EPA [Environment Protection Authority], but their concerns have not been addressed.”

A Newmont spokesperson confirmed Cadia had been “served with proceedings in the Supreme Court of New South Wales in relation to a representative action”.

“Cadia will respond through the appropriate legal processes. As the matter is before court, it is not appropriate to comment further at this time,” they said.

“Newmont takes its legal and regulatory obligations seriously and is committed to environmental stewardship.”

In 2025, the mine was ordered to pay $350,000 in fines after a prosecution by the NSW EPA. Cadia Holdings pleaded guilty to three offences under the environmental protection act relating to breaches of clean air regulations in 2021, 2022 and 2023.

It followed an EPA investigation into Cadia’s management of dust emissions in response to community concerns about air quality in the region.

Also in 2025, an independent review of Cadia’s water monitoring programs commissioned by the EPA found “no conclusive evidence linking Cadia Valley Operations to significant degradation of waterways” but did find elevated heavy metal levels in some groundwater deposits. It also criticised the quality of the monitoring program, citing gaps in the monitoring network, limited data integration, and a lack of formal trend analysis.

In August, NSW Health released the findings of an investigation involving 14 community volunteers from seven properties near the Cadia goldmine.

After reviewing environmental and clinical assessments, the panel found “no definitive evidence of health impacts from heavy metal exposure among volunteers who were assessed”.

A 22-month air quality monitoring program launched by the EPA in 2023 in response to community concerns about the mine found air quality detected at monitors around the mine site was generally good to fair. The program concluded in June last year.