A meeting of the US Groundwater Protection Council (GWPC) earlier this year looked into ‘the hot topics in injection wells,’ providing an inventory of claims and counterclaims in respect of shale gas’ safety. Jean-Philippe Nicot of the Bureau of Economic Geology (BEG) at the University of Texas at Austin advocated ‘fact-based regulation for environmental protection in shale gas development.’ The BEG has performed reviews of technical literature, regulations and records of violations and media claims, noting that, ‘whether hydraulic fracturing for shale gas production has resulted in contamination of ground water and polluted water wells is a very controversial issue.’ Opponents have made bold claims of shale gas’ potential to contaminate groundwater with methane, as shown by the ‘large number of incidences of explosions and contaminated wells in Pennsylvania, Wyoming, and Ohio in recent years*.’ On the other hand, ‘there have been over a million wells hydraulically fractured in the history of the industry [and] not one reported case of a freshwater aquifer ever having been contaminated from hydraulic fracturing.**’ We’ll review the BEG report in next month’s Journal.
Lisa Molofsky (GSI Environmental) has likewise found that methane in Pennsylvania water wells is unrelated to hydraulic fracturing. A pre-drill regional survey found that 78% of water wells contained methane—emanating from shallow glacial till and naturally fractured gas-charged sandstones. Although similar in chemistry, often, Marcellus shale gas can be distinguished from these surface sources. The work is the subject of a 2012 RPSEA proposal for a ‘stray gas investigation protocol’ which will include a pre-drill water sample database and isotopic fingerprinting of gas sources.
Joe Tiago of the EPA provided a status update on the geologic sequestration (of CO2) data system (GSDS). While CO2 use for enhanced recovery is a long-standing practice, sequestration is different—both technically and scale-wise. Federal requirements have introduced a new class of injection well with new reporting requirements for sequestration data. These will feed into a new GSDS repository. Various designs are under consideration—including an HPC platform for analysis and a Drupal content management platform.
In regard of water use, the Texas Water Development Board’s Dan Hardin observed that ‘Fracturing represents less than one percent of the state’s total water use.’ Frac water use is projected to triple by 2020. But even this will still be ‘less than one percent of the state total!’
Scott Kell has been investigating groundwater contamination in Texas and how states are responding to the findings. Contrary to popular belief, incidents are on a downward trend (at least through to 2007). 76 incidents were reported in Texas in the five year period from 1983-87, only 7 in the 2003-07 interval. ‘Incidents’ include deficient primary cement jobs, unsealed flow zones and over pressured annulus. Putting this into context, in the 15 year period from 1993—2008, some 190,000 wells were drilled in Texas and over 5 billion barrels of water injected. Kell concluded that ‘sound science should be foundational to public policy’ and that ‘State investigations are critical drivers of regulatory reform.’ More from the GWPC.
* Robert Howarth, Cornell University, in a written submission to the EPA, 2010.
** Rex Tillerson, Chairman of Exxon Mobil Congressional Testimony, 2010.
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