AGL has voluntarily suspended its pilot project at Waukivory near Gloucester after detecting elevated levels of chemicals used for fracking.
The company announced to the Australian Securities Exchange (ASX) on Tuesday it had detected BTEX chemicals in water samples taken from two of four coal seam gas wells and an above-ground water storage.
BTEX is a group of chemicals (benzene, toluene, ethylbenzene and xylene) are used in the fracking process to extract coal seam gas (CSG).
Use of BTEX chemicals to frack coal seams is banned in NSW.
No BTEX components were used during fracking operations, AGL said in a statement.
The company said the BTEX chemicals detected were "most likely" naturally occurring and could have been drawn to the surface from from deep coal seams.
AGL said its monitoring detected BTEX in concentration of 555 parts per billion in one instance at Waukivory, more than nine times higher than background levels.
The company took five samples in total and four had found BTEX concentrations that ranged between 12 – 70 parts per billion.
The integrity of the highest reading is being reviewed, along with the other sample results AGL said.
BTEX readings of 30 to 60 parts per billion were returned in AGL's baseline groundwater tests taken from the Gloucester basin prior to the pilot project starting.
Flowback water from AGL’s gas wells is captured in a fully contained storage and transferred to licensed water treatment facilities before disposal.
The company said ground and surface water monitoring had shown no changes in quality since commencement of fracking and a full review of the sample results would now be undertaken.
Greens MLC Jeremy Buckingham said the latest incident at Waukivory demonstrated CSG is unsafe.
“BTEX chemicals in the water are an absolute nightmare.
“AGL should pack up and leave the Gloucester valley for good.
“How many more spills, leaks and accidents will it take before the government acts to ban coal seam gas?”
Fracking is a technique to extract gas from coal seams; the seams are fractured under pressure by pumping a mixture of water, sand and chemicals underground to release the gas trapped in the coal.
Water released from the coal seams flows to the surface with the gas - known as flowback or produced water.
More to come
Mike Foley
Senior journalist for The Land.
Senior journalist for The Land.
