The $381 million United Wambo Coal Project in the NSW Hunter Valley has been given the go-ahead to extract an additional 150 million tonnes over a 23-year period by the state's Independent Planning Commission (IPC).

But in an "unprecedented" move by the IPC, any coal extracted from the new 'super pit' near Singleton can only be exported to countries that have ratified the Paris Climate Agreement or have policies for reducing greenhouse gas emissions.

"A condition like this has never been imposed on an Australian coal mine in my experience," said Lock The Gate coordinator Georgina Woods.

"It is unprecedented really to start putting the Australian coal export industry, of which the Hunter is really the core, into a global context of climate change and efforts to mitigate it."

The 'super pit' will see the Wambo Coal Mine and United Coal Mine, which has been under care and maintenance since 2010, join as one new operation.

The companies behind the joint venture, Glencore and Peabody, told the IPC it would provide 500 full-time-equivalent jobs and could extract 10 million tonnes a year for 23 years, operating 24 hours, seven days a week.

While the NSW Minerals Council labelled the condition as "curious", it said the approval was positive news for both the industry and the Hunter Valley's economy.

"It's a good shot in the arm for the sector to see this approval after so long," chief executive Stephen Galilee said.

"I know from visiting the site recently that there was a lot of anxiety among the workforce there in relation to this application and to have it approved … will give them a lot of piece of mind for the future."

Mr Galilee said it was an "ongoing challenge" for the mining industry to minimise the impacts of mining.

"As an industry, we're very aware of the need to minimise our impacts and maximise the benefits and that is a heightened awareness because so many of our mining families live in those communities near the mines where they work," he said.

"We support the Paris Agreement, our industry supports the national government of Australia meeting its Paris Agreement commitments.

"We know we have a role to play there."

Glencore and Peabody said they were "currently in the process of reviewing the details within the IPC's conditions of approval".

The United Coal Mine entered care and maintenance in March 2010, while the Wambo Coal Mine has been in operation for nearly 50 years. ( ABC Upper Hunter: Eliza Goetze )

'On a knife's edge'

A total of 103 public submissions were received as part of the IPC's determination process, 72 of which objected to the project, three were in favour and 16 provided comments.

Noise and air quality, environmental and climate and impacts on water resources were among the concerns raised.

The so-called 'super pit' will extract coal from deeper than the existing operations.

"It's referred to as a 'super pit' because of the depth of the seam of coal that's being targeted," Ms Woods said.

"That's been a cause of concern for a lot of the water impacts that the mine will cause.

"It's going to be adding to the cumulative water drawdown in an already very stressed part of the valley.

"And already people in Singleton are suffering from air pollution that exceeds national standards and this one right in the guts of the mining district of Singleton is only going to intensify those problems."

On a global scale, Lock The Gate said it had mixed feelings about the decision and claimed an additional 260 million tonnes of greenhouse gas pollution would come from the project.

"We are on the knife's edge, globally, in terms of acting to address climate change before it's too late.

"This mine is going to add 260 million tonnes of greenhouse gas emissions to the atmosphere so to simply putting a condition requiring the coal to be only exported to countries that are part of the Paris Agreement, isn't in and of itself going to reduce emissions.

'Surrounded by mines'

Former mining electrician Rob McLaughlin and his wife AnneMaree say they already make reports on air pollution daily. ( ABC Upper Hunter: Eliza Goetze )

Former mining electrician Rob McLaughlin and his wife AnneMaree live near numerous coal mines at their home at Bulga.

They said while they were disappointed United Wambo Coal had been approved, they were not surprised.

"We ring the mines on a daily basis [about air quality] and we have to, when we ring up, determine which mine the dust is coming from, which makes it very hard because we are just surrounded my mines," Ms McLaughlin said.

"Their expansion is taking them over the ridge, which used to protect us a lot from noise and dust to a degree.

"So that means we're going to have more dust, more light, more blast vibrations than we've ever had, and that's a scary thought.

"Here we are in a climate emergency and they're just pumping it out like there's no tomorrow," she said.