http://www.smh.com.au/environment/conservation/plan-to-mine-gas-under-homes-20121228-2bz9w.html
LARGE-SCALE coal seam gas drilling would take place directly under suburban streets and backyards in Sydney under a proposal being assessed by the state’s planning and infrastructure department.
But the gas company AGL has ruled out using the controversial fracking technique at its proposed 66-well gasfield between Liverpool and Campbelltown.
About 10,000 homes in the affected area, covering suburbs such as Currans Hill, Varroville, Kearns, Eschol Park and Denham Court, have been notified of the company’s plans by newsletters.
AGL said there would be no impact at the surface, even for houses directly above the path of a drill.
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”It is possible that horizontal drilling could take place under houses. However it is worth noting that as per the community update provided by AGL, horizontal wells do not cause any impact on surface infrastructure above,” a spokeswoman said.
The proposal before the planning agency is for up to 66 wells at 11 sites. While the surface well heads are mostly between 300 and 400 metres from homes, the plan calls for underground drilling of up to 2.5 kilometres from the surface site, a radius that includes thousands of homes.
The technique involves drilling a well about 700 metres down, then guiding the drill horizontally under the earth to reach sources of underground coal seam gas and create a path for it to be brought to the surface.
But some residents believe not enough is known about methane leaks that appear to be caused by large-scale gas drilling.
They fear that by sucking water and gas up from underground, some gas will find other ways up to the surface, and could end up leaking through fissures in the ground and emerging in suburbs.
”We’re concerned with what we’re seeing in Tara in Queensland,” said Jacqui Kirkby, of the Scenic Hills Association, which opposes coal seam gas drilling in the district.
”Once you de-water a coal seam, the gas can find its way up to the surface and goes wherever it can.”
At the Tara gasfield on the Western Downs, high levels of methane, carbon dioxide and other compounds have been detected at distances of several kilometres from drilling sites.
Ms Kirkby said people she had spoken to in western Sydney generally did not trust AGL’s assurances that the drilling techniques were completely safe.
”I think it’s just that natural tendency for Australians to take things with a grain of salt,” she said. ”AGL won’t ever talk about the potential downsides of what they’re trying to do, so people tend not to believe them.”
New World News 