WA's environment watchdog is facing a big test over plans for an iron ore mine in an ecologically sensitive part of the Goldfields it has previously vowed to safeguard.
Polaris Metals, a subsidiary of mining junior Mineral Resources, referred plans to the Environmental Protection Authority this week to develop an iron mine in the Mt Manning region, about 550km north-east of Perth.
The area, which has some of the world's oldest land formations and is home to rare plants and animals, has long been earmarked for conservation because of its environmental significance.
In its annual report last year, the EPA said it would take a "presumption against" any mining developments in the region until protection had been put in place.
Polaris' referral, which would see between 65 and 115 million tonnes of iron ore mined over the project's life, is set to test the watchdog's resolve.
The area forms an important part of the Yilgarn iron ore province, which the State Government hopes can help underwrite the business case for the long-awaited Oakajee port north of Geraldton.
Mining would be centred on a part of the area called the Helena Aurora Range, also known as Bungalbin.
According to the Wilderness Society, Polaris' proposal would determine whether the EPA had any credibility.
"Bungalbin is an ancient jewel within Western Australia's global biodiversity asset of the Great Western Woodlands," the society's WA director Jenita Enevoldsen said.
"The Helena Aurora Range is so important that there have been calls to formally protect it for more than half a century."
EPA chairman Paul Vogel noted Polaris' referral, which would be followed by a seven-day public comment period, was the first stage in the environmental approvals process.
Once public submissions closed, the EPA would decide the level at which it would assess the proposal, or whether it would assess it at all, Dr Vogel said.
Polaris was contacted for comment.