Propublica reports on a peer-reviewed article by Stephen Osborn et al., «Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing», which was recently published in the Proceedings of the National Academy of Sciences. Excerpts from the abstract read as follows:
«In aquifers overlying the Marcellus and Utica shale formations of northeastern Pennsylvania and upstate New York, we document systematic evidence for methane contamination of drinking water associated with shale gas extraction. (...) We conclude that greater stewardship, data, and— possibly—regulation are needed to ensure the sustainable future of shale-gas extraction and to improve public confidence in its use.»
The article mentions hypotheses about the mechanisms causing drinking water contamination from fracking: 1) gas migration; 2) leaky gas-well casings; and, 3) increased connectivity of the rock formation due to extensive fracturing. Only options 2) and 3) appear probable to the authors, with leaky gas-well a likely possibility.
Hopefully, this type of evidence will be considered in the strategic environmental study to be conducted on shale gas exploitation in Québec.