Environmentalists and farmers at an independent planning commission were locked in disagreement over a proposed South Korean-owned coal mine in Bylong Valley, north-east of Mudgee.

Key points: The Bylong Valley coal mine has an expected lifespan of 25 years

The Bylong Valley coal mine has an expected lifespan of 25 years South Korean mining giant Kepco has already invested more than $700 million developing the project

South Korean mining giant Kepco has already invested more than $700 million developing the project The mine is projected to produce 6.5 million tonnes of coal a year

Hundreds of people, including dozens of protestors, turned out to the meeting in Mudgee to have their say on the Kepco mine, which is expected to generate more than 6.5 million tonnes of coal per year.

Kepco plans on constructing a series of open-cut and underground mines with an expected operating period of 25 years.

They said it was expected to create 645 mining jobs.

They said the operation was expected to inject more than $300 million into New South Wales, including $278 million in royalties.

The commission heard from more than 60 speakers, both for and against the mine, as part of its decision-making process to approve the mine.

Local man Travis Rixon told the commission the mine would be a huge benefit for the area and lambasted "professional protestors" who were removed from community concerns.

Mudgee resident Robbin Binks, who grew up in Bylong, strongly opposed the mine and told the meeting that Kepco had "divided, conquered and gagged" an area and made it an "unpleasant place to live".

The mining company has spent more than $700 million developing the project, which includes buying up many historic homes and farms in the Bylong Valley area, as well as thoroughbred studs and even the local school.

Farmer Graham "Tag" Tanner and Warwick Pearse from the Bylong Protection Society. ( ABC News: Liv Casben )

Graham "Tag" Tanner, a farmer whose 800 acres borders the Kepco site, said he was due to sell his land to the mining giant, but negotiations had broken down weeks earlier.

"The traffic, the noise, the dust is going to be horrific," Mr Tanner said.

"They say they can control our dust but they must be better than me, because I don't think anybody can control the dust.

"In my opinion, there's not enough water here for farming and mining. I've told them that it's either one or the other."

However, not all residents were convinced by the potential environmental impact, with 459 people in the nearby towns of Rhylstone and Kandos signing a petition in support of it.

Margaret Hart, the publican at a Rhylstone pub, believes the mine should be approved, saying it would double the town's population of 600.

"Because the staff would be living here, it would obviously turn over a lot more money in the shops and cafes, everything," she said.

The mining company said it had submitted a revised plan that would reduce the mine's environmental impact.

The independent planning commission is considering the revised plan and is expected to make a decision by the end of the year.