Australian gold miner Newcrest has reduced the underground mining rates at its Cadia gold and copper mine after the state’s environmental authority found it was producing “unacceptable” levels of dust.

In June, the New South Wales Environmental Protection Agency (EPA) ordered the company to take immediate action on the levels of dust pollution produced by its operations. The agency found the mine to be falling “well short” of its legal obligations to meet clean air standards.

Tony Chappel, EPA chief executive officer, said in a statement at the time: “We require the mine to take all necessary steps to ensure dust emissions are significantly reduced and this may include a reduction in production.” He warned that if Newcrest does not demonstrate action, the EPA will take “appropriate action”, which could include suspension of the company’s operating licence, seeking court orders or issuing further directions.

“We know this is strong action, but we will not shy away from doing what we must to prioritise human health and the environment,” Chappel added. The EPA also said that the Department of Planning and Environment was separately investigating whether the company has complied with conditions of consent in relation to ventilation shafts.

In an update to investors on Tuesday, Newcrest confirmed that it has made adjustments to Cadia’s underground operations to comply with the EPA’s request for action. This includes a reduction in mining rates, the Sydney Morning Herald reports. Other changes include modifications to the mine’s ventilation circuit as well as the installation of additional dust control equipment such as dust sprays and spray curtains.

The company said that it did not expect material impacts to the mine’s overall production as a result of slowed operations, largely because surface-level reserves could be used to fill gaps in output if necessary.

“Cadia continues to work openly and transparently with the Environmental Protection Authority and the local community to ensure all statutory obligations are met in a way that is aligned with Newcrest values,” the company said. It added that it expects to see a human health risk assessment by September, which will provide a “comprehensive scientific picture” of the overall air quality in the area and potential impacts on the health and well-being of local communities.

The Cadia mine has faced other significant health allegations this year. In May, dozens of residents from the village of Millthorpe in west New South Wales, including children, reported blood test results that showed high levels of heavy metals.

In May, Newcrest agreed to a takeover deal by mining behemoth Newmont worth $19bn (A$28.03bn) after an initial offer of $16.9bn was rejected in February.