The energy company wants to drill 72 gas wells near Campbelltown as part of the northern expansion of the Camden Gas Project.

AGL said the expansion would produce a convenient supply of gas for the Sydney region and create jobs.

But Carmelite friar Father Greg Burke feared the peace and quiet that had drawn visitors to the Mount Carmel Retreat Centre since the 1960s would be threatened by noise and traffic if gas mining went ahead.

"Coal-seam gas in the Scenic Hills is the beginning of the ruination of everything we stand for," he said.

"We're kind of an urban lung here in the Scenic Hills.

"As a religious group what we're trying to do is preserve that amenity for all of Macarthur and also all of Australia."

Father Burke said he also had concerns about letting mining companies access the land.

AGL land and approvals manager Adam Lollback said it was company policy to negotiate and work with land owners when it came to the location of gas wells, access roads, gates and gas gathering lines.

Carmelite nun Jocelyn Kramer said many people in the area had no idea about the plans or that they were so far advanced.

"Some of them are quite appalled when they find out," she said.

The Serbian Orthodox Church in Australia spokesman Randon Illic said members feared the planned expansion would destroy their plans for a school in Varroville.

"The location of the proposed well is on our land and there is a risk of contamination both of the surrounding air, surrounding soil and water table," Mr Illic said.

"The proposed access way to the well runs right past the front of the school, less than 20 metres from the entrance.

"Our primary concern is the potential health risks to students, staff and visitors to the school and the same risks to others in our Varroville community and indeed the wider area affected by the proposal."

AGL believed the industry can comfortably exist side by side with many other land uses and industries.

Resources and Energy Minister Chris Hartcher has placed a moratorium on the controversial fracking process until the end of the year and banned the use of harmful chemicals in drilling.