According to the Paris-based International Energy Agency... operating with a near-zero-impact environmental footprint would add
about 7 percent... to the typical cost of a well
in mainland USA...
more at: http://www.nytimes.com/2012/06/10/opinion/sunday/natural-gas-by-the-book.html
more at: http://www.nytimes.com/2012/06/10/opinion/sunday/natural-gas-by-the-book.html