By Peter Aldhous
Don’t blame fracking for environmental problems associated with extracting gas from shale. That’s the message of a new report from the Energy Institute at the University of Texas at Austin, released on the opening day of the AAAS meeting in Vancouver, Canada.
The US is riding the wave of a shale gas boom driven by fracking, or hydraulic fracturing – in which the rock is injected with water, sand and chemical additives at high pressure to release trapped methane.
Other nations are keen to follow this lead, and lead author Charles “Chip” Groat hopes the report will help regulators worldwide separate “fact from fiction”. Reviewing existing studies, Groat’s team could find no evidence linking groundwater contamination to fracking operations many hundreds of metres below.
A recent New Scientist analysis came to a similar conclusion. But this doesn’t mean that shale gas extraction is benign, as the Texas team’s review of the industry’s track record revealed.
Groat’s team looked at breaches of environmental regulations in shale gas extraction in four states: Texas, Michigan, New Mexico and Louisiana. While many were simply procedural, some involved significant pollution. In Texas, for instance, 21 out of 72 breaches that occurred between 2008 and 2011 had “substantial” environmental consequences.
The problems were not caused by the process of fracking itself, but instead related to issues like ruptured well casings that also affect conventional gas production, or surface spills of chemicals or wastewater.
“We found no direct evidence that hydraulic fracturing itself had contaminated groundwater,” says Groat. “We found that most of the violations were at or near the surface.”
Still, with the shale gas boom occurring mostly in regions where residents are not used to seeing drilling rigs, fracking is getting a bad press. The Texas team analysed media coverage of fracking in areas above three the major shale gas deposits in the US, finding that about two-thirds was negative in tone.
Expect more controversy to come – especially around the issue of whether leaks of methane from fracked wells negate the benefits of a “low-carbon” fuel that is billed as a climate-friendly alternative to coal. While the Texas study was being conducted, researchers at Cornell University in Ithaca, New York, estimated that as much as 7.9 per cent of the methane from a shale gas well leaks into the atmosphere during its lifetime - up to twice the amount from conventional gas production.