NSW Court of Appeal has upheld the decision to refuse the Bylong Coal Project - a ruling welcomed by those who have spent years fighting the proposed 'greenfield' coal mine.

The Bylong Valley appears to have been saved from the development of a 'greenfield' coal mine thanks to the latest court decision in what has been a lengthy legal battle.

With the NSW Court of Appeal's ruling this week, to uphold an early court decision to refuse the Bylong Coal Project, those who campaigned long and hard against the proposed coal mine were celebrating but also calling for a NSW Government guarantee that Bylong is truly protected with the coal licence for the valley extinguished.

Korean company KEPCO wanted to build a mine capable of extracting 121 million tonnes of thermal coal over 25 years known as the Bylong Coal Project but their plans were first rejected by the Independent Planning Commission (IPC) in 2019 a decision upheld by the NSW Land and Environment Court and now the NSW Court of Appeal.

IPC in their determination said the risks posed by the proposed coal mine to water, land, and future generations through its contribution to climate change were too great.

Bylong Valley Protection Alliance spokesperson Phillip Kennedy said the NSW Government must act now to secure the land for farming families, so Bylong could once again be home to a thriving community.

"KEPCO's foolish foray into Bylong has driven farmers and their families out. There is no one operating the local store any more - the valley is a shell of its former self," he said.

"This is the reality of what happens when a coal mining company tries to come to town.

"Despite all this, there is still a community here. We want the Berejiklian Government to extinguish the coal licence, just like it did with Shenhua on the Liverpool Plains, so Bylong can once again be the prosperous town it used to be."

IPC in their determination said the risks posed by the proposed coal mine to water, land, and future generations through its contribution to climate change were too great.

In the Court of Appeals judgment is stated "KEPCO has not established any of its five grounds of appeal against the primary judge's dismissal of its challenge to the IPC's decision. The appeal should be dismissed with costs."

Environmental Defenders Office Managing Lawyer Rana Koroglu said "This is the third time this destructive and climate-wrecking coal mine proposal has been defeated - first in the Independent Planning Commission, then in the Land and Environment Court, and now in the NSW Court of Appeal. It's time for the proponent KEPCO to walk away."

"The most recent Intergovernmental Panel on Climate Change report delivered a 'Code Red' for humanity on climate. It's clear we cannot afford to develop more greenfield coal mines at a time when the world needs to rapidly reduce greenhouse gas emissions. The South Korean Government, a majority stake owner in KEPCO, has recently committed to increasing its emissions targets to a 40% reduction by 2030.

"Our evidence before the IPC hearing was compelling and robust. We presented testimony from over a dozen expert witnesses and put the latest scientific evidence before the Commission.

"The IPC made its decision based on that evidence, finding that this coal mine is not in the public interest. Two subsequent appeals have thoroughly tested and supported the IPC's decision to refuse the mine.

"We are delighted for our clients, the Bylong Valley Protection Alliance, who have once again successfully argued for the rejection of this mine and defended their beautiful valley."