In the Marcellus shale region, elevated concentrations of dissolved methane in private water wells has been shown to be linked to natural gas extraction, but little is known of the connections between methane, gas production, and water chemistry. This study evaluates the relationships of methane to the major chemical constituents of groundwater by comparing analytical data obtained from a stray gas investigation by the Pennsylvania Department of Environmental Protection (PADEP). Furthermore, spatiotemporal relationships of dissolved methane to gas well production and total iron (Fe) concentrations of groundwater to adjacent gas wellheads are examined. The objectives of this study were to identify essential pre- and post-drill test parameters that are sensitive to methane, and to determine what water types are associated with stray gas. It was discovered that total Fe concentrations in groundwater increased and sulfate (SO4) concentrations decreased likely as the result of redox reactions by anaerobic microbes in the presence of stray gas. Therefore, total Fe and SO4 should be mandated pre- and post-drill test parameters for baseline water quality assessments.