Many of you may have seen this kind of video, showing the
effects of methane in drinking water near some shale gas
extraction wells: Before now, I've never known what to make of
this kind of thing. Is this a very rare, if spectacular
occurence, or is it common where shale gas drilling goes on?
Now, there is a paper in this week's PNAS, Methane contamination
of drinking water accompanying gas-well drilling and hydraulic
fracturing by Osborn et al, researchers at Duke University. It
appears to answer the question, and the answer is not good.
Basically, they sampled well water from 68 private wells above
the Marcellus and Utica shales in Pennsylvania and New York.
About a third were in an "active extraction area", defined as
within 1km of a gas well, while the rest were further away. They
then measured the concentration of methane in the water. The
results are as follows: Technical Measures for the Investigation
and Mitigation of Fugitive Methane Hazards in Areas of Coal
Mining. That report establishes the follo