Fracking is more likely to occur in the Sydney basin while drilling for coal seam gas takes place than in other Australian gas fields, a senior NSW scientist has reported.
Through freedom-of-information laws the Greens have obtained an unpublished state government commissioned report in which the Chief Scientist and Engineer, Mary O'Kane, concludes companies would be likely to start fracking once ''sweet spots'' for gas have dried up, SMH reported.
Because of Sydney’s rock strata and the age of the coal deposits, the report suggests if large-scale coal seam gas drilling begins, fracking will probably end up being used.
Fracking is a drilling technique that forces gas to the surface by pumping a mixture of water, sand and chemicals underground.
Those opposed to the practice say it can result in surface gas leaks, cracking of underground aquifers, and water pollution.
Referring to coal seams in Sydney, Gunnedah and Gloucester, O’Kane wrote: ''Coal seams from some basins in NSW appear from the advice to be more likely to need fracturing than others”.
''In the later stages of coal seam gas developments after the high permeability coal seams or 'sweet spots' have been drilled, it is more likely that wells will then be [fracked] to increase production.''
O’Kane added that technological advancements may reduce the need for fracking.
''The development of new technologies may significantly reduce the need for hydraulic fracturing in the future.''
Just this week AGL publically reversed its position on fracking, putting the drilling technique back on the table as a possible option.
Gas company AGL plans to drill 66 wells in western Sydney, between Campbelltown and Liverpool, promising there will be no surface impact from the drilling, SMH reported.
If the AGL project is approved, the Greens say fracking is inevitable under Sydney.
''Our aquifers and geological formations are like Humpty Dumpty, once you've fracked it, you can't put it back together again,'' Greens member Jeremy Buckingham said.
''Barry O'Farrell should act now to protect land and water rather than leaving it to a future government to say sorry for the damage done by fracking for coal seam gas.''
Recently, protests have erupted in both the Hunter Valley and Northern Rivers regions in an effort to stop the development of coal seam gas operations.