The National Ground Water Association has a press release discussing a new article in Groundwater finding:  "Testing of 1,701 water wells in northeastern Pennsylvania shows that methane is ubiquitous in groundwater, with higher concentrations observed in valleys vs. upland areas and in association with calcium/sodium/bicarbonate, and sodium chloride-rich waters."  (Emphasis is ours.)  The press release continues:  "The article goes on to say that 'on a regional scale, methane concentrations are best correlated to topographic and hydrogeologic features, rather than shale-gas extraction.'"