Higher-risk 'Shallow Fracking' More Common than Suspected: S

Higher-risk 'Shallow Fracking' More Common than Suspected: S

Postby Oscar » Mon Jul 27, 2015 11:28 am

Higher-risk 'Shallow Fracking' More Common than Suspected: Study

[ http://thetyee.ca/News/2015/07/27/High- ... ign=270715 ]

Lessons for BC, Alberta in new Stanford report.

By Andrew Nikiforuk, July 27, 2015, TheTyee.ca

The fracking of oil and gas less than a mile from aquifers or the Earth's surface now takes place across North America with few restrictions, posing increased risk for drinking water supplies, says a new Stanford study. [ http://pubs.acs.org/doi/abs/10.1021/acs ... ode=esthag ]

The study examined the frequency of so-called shallow fracking, described by the researchers as occurring less than a mile underground. Shallow fracking poses a greater risk to drinking water than fracking that occurs much deeper under the Earth's surface.

Out of 44,000 wells fracked between 2010 and 2013 in the United States, researchers found that 6,900 (16 per cent) were fractured less than a mile from the surface and another 2,600 wells (six per cent) were fractured above 3,000 feet, or 900 metres.

"What surprised me is how often shallow fracturing occurs with large volumes of chemicals and water," said lead researcher and environmental scientist Robert Jackson in an interview with The Tyee.

The majority of shallow fracking now takes place in Texas, California, Arkansas and Wyoming. Although the study largely excludes Canada, shallow fracking also takes place in Saskatchewan, Alberta, Quebec, Manitoba and British Columbia, and sometimes at depths less than 500 metres.

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As a result, shallow fractures can connect to aquifers used for drinking water.

"Even fractures that do not extend all the way to an overlying aquifer can link formations by connecting them to natural faults, fissures or other pathways," explained the study.

Scientific studies have documented contamination of freshwater aquifers by fracking or fracking chemicals since 1984.
[ http://onlinelibrary.wiley.com/doi/10.1 ... x/abstract ]

Fracking into water zones has been an issue for the technology since the 1950s.

Patents filed by industry repeatedly complain "it is not uncommon during hydraulic fracturing for the fracture to grow out of the zone of productive interest and proceed into a zone of non-productive interest, including zones containing water."

"There are more risks with shallow fracking," explained Jackson, because the separation between the zone being fracked and nearby aquifers is less, resulting in "the potential of directly connecting a fracture with an aquifer. It's just common sense."

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Prior to the shale gas revolution, the shallow fracturing of coal seams to extract methane resulted in hundreds of cases of groundwater contamination and gas migration in Australia, [ http://pubs.acs.org/doi/pdf/10.1021/es304538g ] New Mexico, [ http://cogcc.state.co.us/documents/libr ... an_BLM.pdf ] Colorado, China, Alberta [ http://www.ernstversusencana.ca/wp-cont ... Canada.pdf ] and Alabama.

Jackson found it surprising that "there are no limits on how shallow fracturing can be in the U.S. No state has an upward limit."

Nor does Canada: the Alberta Energy Regulator, which once described shallow fracking as "high risk" in a 2004 presentation, allows companies to perform high-volume frack jobs on wells shallower than 200 metres as long as they are located a short distance away from water wells.

In B.C., drillers can fracture zones at a depth of 600 metres but must get a permit to do so first.

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Fracking pollutes: EPA

Last June, the U.S. Environmental Protection Agency concluded in a 500-page draft report that fracking has polluted ground and surface water in cases ranging from Alberta to Pennsylvania. [ http://thetyee.ca/News/2015/06/08/Water ... -Fracking/ ]

"Some hydraulic fracturing operations are conducted within formations that contain drinking water resources," the report found, as did Jackson's new study.

"In one field in Alberta, Canada, there is evidence that fracturing in the same formation as a drinking water resource (in combination with well integrity problems)... led to gas migration into water wells," said the EPA study.

According to the study, underground fracking operations have propelled fluids and gases out of the targeted areas "into underground drinking water resources," often through pre-existing fractures and pathways such as nearby abandoned or leaky wells.

In one example, the EPA reported that fracking had contaminated 25 per cent of 36 water wells in northeastern Pennsylvania, though the agency "did not find mechanisms have led to widespread, systemic impacts on drinking water resources in the United States."

In contrast, state agencies in Ohio, Pennsylvania, Texas and West Virginia have reported myriad problems, including hundreds of complaints about groundwater contamination due to fracking.

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ENERGY: [ http://thetyee.ca/Topic/Energy/ ]

ENVIRONMENT: [ http://thetyee.ca/Topic/Environment/ ]

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Andrew Nikiforuk is an award-winning journalist who has been writing about the energy industry for two decades and is a contributing editor to The Tyee.
Find his previous stories here: [ http://thetyee.ca/Bios/Andrew_Nikiforuk/ ]
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