ASSESSMENT OF ENVIRONMENTAL IMPACTS CREATED BY THE COUNCIL RUN GAS FIELD IN NORTH-CENTRAL PENNSYLVANIA

The Council Run gas field is located near the eastern edge of the Appalachian Plateau in north-central Pennsylvania. Occupying parts of both the Allegheny Front and Deep Valley sections, this area generally is underlain by shale, siltstone, and sandstone. Discovered in the early 1980s, Council Run is roughly 290 square miles in size and harbors over 730 individual gas wells typically drilled on 40-acre spacing. Estimated ultimate recovery for the field is approximately 250 billion cubic feet (bcf) of gas with average field production close to 200 million cubic feet of gas (mmcf). Natural gas is produced from Late Devonian age sandstones of both marine and non-marine origins. The producing sandstones are members of the Catskill and Lock Haven formations. Individually, these sandstones are referred to as the Elk and Bradford sands.

The goal of this study is to examine potential environmental impacts created by the establishment of producing gas fields using data gathered from the Council Run field. Previous research exists on similar topics but has overwhelmingly focused on the biological and ecological impacts associated specifically with natural gas transmission lines (pipelines), power transmission lines, and forest fragmentation. Earlier workers failed to devote significant, if any, attention to the impacts directly resulting from or associated with natural gas production and the surrounding geology. The intent of this paper is to present the impacts associated with shallow gas drilling in the Council Run field as determined at the conclusion of this study.

Regional climatic variation, as a result of gas production, was determined to be an environmental impact of any gas drilling program. Localized variation occurs as a result of canopy loss or any geologic/geomorphic change that is directly associated with gas production. Data were collected from both pre- and post-development well sites. Climatic variables were recorded over stable, measured distance intervals radiating from the well head into the undisturbed canopy or other native vegetation. Individual well sites were delineated and classified using a unique classification scheme developed specifically for this research. The results presented in this paper are meant to serve as a basis for similar applications in other regions.