Baseline Water Chemistry Characterization in an Area of Developing Shale Gas Activity

The recent increase in the development of shale formations for the purpose of natural gas extraction in the mid-Atlantic, namely the Marcellus shale, can be attributed to advances in unconventional extraction methods. This includes horizontal drilling and multistage hydraulic fracturing, a process that uses water to pressurize and fracture relatively impermeable shale layers to release natural gas. In West Virginia, the U.S. Department of Energy estimates 95 to 105 trillion cubic feet (TCF) of expected ultimate recovery (EUR) of natural gas from this formation [ALL Consulting, 2010]. Increased development of unconventional shale gas formations are accompanied by concerns of potential contamination to shallow groundwater resources, which often serve as potable water sources for many rural communities. However, the impacts of this practice on water resources are poorly understood due to lack of controlled preversus post-drilling monitoring, a consequence attributed to the rapid development of this resource.;To address knowledge gaps associated with the potential impacts of unconventional shale gas development on water resources, a pre-versus post-drilling study has been initiated by the USFS in the Monongahela National Forest. This study consists of three major objectives; (1) a comprehensive literature review examining the current state of understanding about unconventional natural gas extraction and its potential to impact shallow groundwater resources; (2) the development of a sampling protocol that outlines equipment and procedures necessary for the collection of water samples for the purpose of this study; (3) the characterization of surface and groundwater chemistry used for direct and indirect sources of drinking water in the Summit Lake area of the Monongahela National Forest prior to drilling, establishing baseline water chemistry conditions. Pre-drilling water samples were collected and analyzed from two groundwater wells, a shallow spring, a nearby lake, and a river to identify potential endmembers. Geochemical analyses included major ions, trace elements, dissolved methane concentrations, carbon and hydrogen isotope concentrations of dissolved methane (delta13CCH4 and delta2H CH4), oxygen and hydrogen isotope compositions in water (delta 2HH20 and delta18HH20), sulfur and oxygen isotope compositions of dissolved sulfate (delta34S SO4 and delta18OSO4), carbon compositions of dissolved organic carbon (delta13CDIC ), and radium isotopes (226Ra and 228Ra). This analysis serves as a baseline of local water chemistry around Summit Lake, West Virginia, from which to evaluate potential changes before, during, and after shale gas extraction