A new Queensland coal mine, about the same size as Adani's controversial project, did not draw opposition from environmentalists during the approval process, despite the possibility an expansive koala habitat the size of Sydney Harbour may be cleared.

Key points: The Olive Downs project is digging for coking, which is a vital ingredient to make steel and not considered as harmful to the environment

The Olive Downs project is digging for coking, which is a vital ingredient to make steel and not considered as harmful to the environment No environmental group made submissions to Queensland's required public consultation process

No environmental group made submissions to Queensland's required public consultation process An expansive koala habitat is to be cleared, and three open-cut pits are to remain after the mine ends

Australian-based Pembroke Resources had its Bowen Basin mine approved by the state's independent coordinator-general on Tuesday and will start construction next year if the Federal Government gives it the go-ahead.

About 55 square kilometres of koala habitat will be cleared, with the coordinator-general recommending a significant offset to protect the vulnerable species.

The mine site, considered one of Australia's biggest, also includes 11 highly significant wetlands.

During the state's required public consultation process, not one environmental group made a submission.

The Australian Conservation Foundation (ACF) said it was spread too thin and had decided to target thermal coal projects.

Pembroke Resources' Olive Downs project is digging for coking, or metallurgical coal, which is a vital ingredient to make steel and not considered as harmful to the environment.

The open cut metallurgical coal mine includes two mining areas, the Olive Downs South and Willunga domains. ( www.pembrokeresources.com.au )

"Thermal coal projects have readily available alternatives," the ACF's Gavan McFadzean said.

"We don't need to be burning thermal coal for electricity generation anymore.

"The environment movement can only campaign on so many coal projects at any one time and we have to be selective on which ones we target.

"We don't like any coal mine being approved ... it's a question of where the project is."

Mine 'gets through state loophole'

Environmental group Lock The Gate Alliance campaigner, Carmel Flint, said the mine was not as problematic as Adani's project, which is slated for the virgin Galilee Basin.

"I think a lot of groups are concerned about the Carmichael coal mine because it's the first proposed mine in an entirely new basin," she said.

"The Galilee coal is a thermal coal basin, which is a great contributor to global warming and there are more concerns about opening a massive new basin in that regard."

Despite not making formal submissions to the approval process, Lock the Gate called on the coordinator-general to prevent Pembroke Resources from leaving "voids" when the mine was finished.

The Mary Kathleen uranium mine in north-west Queensland closed in 1982 and left an open pit void, similar to those environmentalists say could be a problem at Olive Downs. ( Wikimedia )

The mine would create 13 open-cut pits over the course of the project.

Although 10 would be completely backfilled, three final voids would be left, covering around 10 per cent of the project site.

The coordinator-general's report said Pembroke Resources estimated it would cost $3 billion to backfill the final voids to ground level, making the project economically unviable.

Lock the Gate campaigner Rick Humphries said: "When you have large unrehabilitated voids left at the end of a mine's life on flood plains the chances of flooding are very high risk".

"Those pit lakes that form, which are very contaminated and highly saline, get this flush of toxic material out into the rivers."

Mr Humphries said the approval contradicted changes to legislation in 2017 that sought to ban leaving voids on floodplains.

Voids, like this one at the Mount Oxide copper mine north of Mount Isa, are flagged as a concern by environmental groups. ( Supplied: Lock The Gate )

The coordinator-general's evaluation report said Olive Downs had "transitional provisions" because it had applied for an Environmental Authority prior to the legislative changes.

The report said the approval was subject to strict conditions, including building a wall to prevent flood waters from entering them.

"Final voids must be rehabilitated to a safe and stable landform that does not cause environmental harm and can sustain a post-mining land use," the report said.

Olive Downs 'doesn't get the publicity'

AME Research resources analyst, Lloyd Hain, suspected there were other reasons Olive Downs had not piqued the interest of environmentalists.

"I just think there's not much traction in the media in attacking a small Australian company doing a coking coal mine in the existing Bowen Basin," he said.

"I think the environmental groups are choosing battles where they can get the most attention.

"We've actually seen in the past 12 months there's been a couple of coal mines approved in the Bowen Basin and there's been zero outcry from environmental groups at all."

A number of mines already exist in the Bowen Basin, which sits north of the Galilee Basin. ( Macarthur Coal: AAP Image )

Pembroke Resources said the Bowen Basin's coking coal reserves was one of the biggest in the world and its product will be mainly exported to Asia.

Chief executive Barry Tudor said the mine was expected to run for 79 years and create 1,000 ongoing jobs.

"There's very limited high quality metallurgical coal mines left in the world, let alone in the Bowen Basin," he said.

"So we see this as quite a rare opportunity to develop a mine of a tier one, world-class standard."

Isaac Regional Council Mayor, Anne Baker, said they had been working for some time to look at how the large workforce could be housed.

"There's been quite a serious body of work and it is ongoing in relation to identification of available land, either accommodation that is built and unused or approved and unbuilt and also vacant land," she said.