Results from more than 1,700 water wells sampled and tested prior to proposed gas drilling in Susquehanna County, PA. show methane to be ubiquitous in shallow groundwater, with a clear correlation of methane concentrations with surface topography. Specifically, water wells located in lowland valley areas exhibit significantly higher dissolved methane levels than water wells in uplands areas, with no relation to proximity of existing gas wells, and suggests that the presence of methane is more a function of geology than of shale gas development.