They have joined the chorus of angry communities across NSW fighting against mining companies with licenses to explore for coal seam gas deposits.

Campbelltown's prized green space has been earmarked for the Camden Gas Project's northern expansion and if the plans, which are currently before the state government, are approved, 72 gas extraction wells will be drilled.

AGL land and approvals manager Adam Lollback said the expansion would produce a convenient supply of gas for the Sydney region and create jobs.

However, residents are worried about the impact of mining infrastructure, such as drilling rigs, heavy trucks and water pumps, travelling on suburban streets.

They also have concerns about the impact of coal seam gas mining on drinking water, health and the environment.

Joy Corcoran and her husband, Col, have lived in Varroville for eight years and said there would be gas wells a couple of kilometres from their St Andrews Road home.

"It's going to ruin the beautiful Scenic Hills," Mrs Corcoran said.

"We're going to have trucks going up and down this road which was only meant for cattle trucks.

"We don't know what they're spurting into the air.

"They're not communicating with us.

"There are 26 houses in our area and they didn't come around to any of them."

Mr Lollback said AGL had taken traffic and noise considerations into account and they would be required to operate under any RTA regulations and restrictions.

"The Camden Gas project has a proud history of co-existence within the local community, which is evidence that the industry can comfortably exist side by side with many other land uses and industries," Mr Lollback said.

He said the company had an extended exhibition period for northern expansion and had hosted one-on-one briefings with stakeholders and publicised the plans on their website.

Macquarie Fields MP Andrew McDonald said the onus was on mining companies to prove coal seam gas extraction was safe.

He has called on the state government to refuse to renew AGL's license to mine in the area, which expired in March.

Campbelltown MP Bryan Doyle said an Upper House inquiry into coal seam gas mining has been announced, with public submissions due by September 7.