EPA looks into Sydney coal seam gas leak

The Environment Protection Authority (EPA) is investigating a gas leak from an AGL coal seam gas site on Sydney's southwest fringe.

Authorities have given the all clear for the Camden area after members of the community reported hearing a loud bang and "hissing" noises at the site on Sunday night.

Firefighters isolated the gas and sprayed water in the area to disperse a vapour cloud which was only around 200m from some homes.

An AGL spokesperson said that a small amount of natural gas had escaped.

"A safety release valve was activated, causing a loud hissing noise.

"At no time were any local residents at risk," she said.

The EPA is investigating whether AGL breached its operating licence.