Much written here is related to fraccing.  Recently, the CEO of Chesapeake commented on this topic.  His point is very valid.  Ninetynine percent of ground water problems come from poor cementing when drilling the well.  In 30 plus years never heard about fracks causing water problems (first frac in 1979).  On the other hand poor cement jobs has been known to cause problems with ground water.  Further, soil cement mixes used to stabilize drill pads can leave the runoff well above pH 12.  This is where the concern should be focused.