Contributed by: Grace Kovalan, Student Research Fellow
In recent years, there has been an extreme increase in the number of horizontally drilled shale oil and gas wells nationwide. This has led to concerns regarding the potential effects on nearby stream ecosystems. A study was conducted on the evaluation of these geochemical and biological effects based on this development in shale gas.
Over two consecutive years, twenty-five small watersheds in Pennsylvania, which drain into lands rich being utilized for shale gas development, had its water tested for contaminates seasonally. While seasonal differences were observed in the stream chemistry, the study indicates no significant relationships between the intensity of oil and gas development, geochemical tracers, or benthic zone community composition. The study ultimately shows that there is no real effect on the tested watersheds from shale gas development. This also shows a need for considering the importance of spatial and temporal variability in streams.
While there is no real relationship between the intensity, presence, or absence of shale gas development and any chemical constituents found, other concerns still remain. These concerns pertain to activities associated with oil and gas development and production. Such activities may include: releasing hydraulic fracturing fluid and wastewater, erosion, road use, waste disposal, and sedimentation from construction and operating well pads, pipelines, and roads. Although these activities are not direct impacts, they are still caused by oil and gas development, and, therefore, pose an environmental concern.
With the development of oil and gas resources, using natural gas as an energy source is ever so important in today's day and age. It is especially relevant to Pennsylvania because of the increase in both production and the amount of hydraulically fractured wells, as PA accounts for 20% of the United States’ natural gas production. Because of the ample Marcellus Formation in PA, it has made for a prominent area to compose shale oil and gas wells. The production of shale oil and gas, specifically in PA, has made for many jobs and has notably boosted the industry overall.
In regards to regulating shale gas development, the Pennsylvania Department of Conservation and Natural Resources (DCNR) closely oversees the Pennsylvania State Forests to ensure that all necessary precautions are taken to maintain the ecosystems; they have implemented frequent inspection programs to control permit requirements and lease provisions. In a statement to the Pennsylvania Business Report, representatives from the DCNR held that the report “confirmed [that] the current management practices in the state forests were doing the job”, and there are no current proposals for any policy changes.
The study conducted concludes that there is no quantifiable relationship caused by drilled shale oil and gas wells and stream chemistry. While there is no direct effect, there are indirect environmental effects that, although organizations in Pennsylvania are taking precautions to oversee these processes, still occur and should attempt to be more controlled.