Association between unconventional oil and gas (UOG) development and water quality in small streams overlying the Marcellus Shale

Abstract

Unconventional oil and gas (UOG) development has increased dramatically in the Marcellus Shale region over the past decade, and there is widespread public concern about the potential effects that UOG development may have on water quality. The goal of this study was to assess whether a suite of stream water quality constituents was related to the intensity of UOG development in corresponding catchments. Nineteen streams in southwestern Pennsylvania, where UOG development is prevalent, and 10 streams in western Maryland, where no UOG development has occurred, were sampled in summer 2013. Dissolved metals, radium isotopes, radon, specific conductance, stream discharge, and pH were measured. Principal component analysis revealed that samples tended to cluster by state, but some overlap in water quality existed between Maryland and Pennsylvania. Linear models were used to assess how response variables were related to UOG, other extractive activities, and landscape characteristics. These models showed that an index of oil and gas development had significant explanatory power for specific conductance, As, Ca, K, Mg, Na, and Sr. Other land use and land cover variables, such as forest, urban development, and coal mining, as well as stream discharge and pH, also were significantly associated with response variables. These results suggest that, in the Marcellus Shale region, UOG may elevate specific conductance and dissolved element concentrations in streams, but it should be considered in the context of broader patterns of land use and human activity.

Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multiparameter study in Pennsylvania

“…Previous studies have shown significant effects downstream from discharges from municipal and industrial wastewater treatment plants treating produced water (26,30) and shale gas wastewater disposal facilities (29), and large spill events (24,28,29), but the regional effects of shale gas development on stream environments remain unclear. Previous work has also shown an inability to confidently identify an OG signal when faced with other land uses (8), which are more likely to cooccur in a watershed as size increases.…”

Arsenic release to the environment from hydrocarbon production, storage, transportation, use and waste management

“…The mechanism responsible for the As in groundwater was not identified, and it was noted that the mobilization of geogenic constituents into private wells could have been caused by mechanical disturbances from intense drilling activity, reduction of the water table by drought or groundwater withdrawals, and faulty gas-well drilling equipment or well casings (Fontenot et al, 2013). Knee and Masker (2019) evaluated whether stream water quality constituents, including As, were related to the intensity of UOG development in catchments in the Marcellus Shale region. They found significant positive relationships between As concentration in streams and UOG well density but the mechanism of mobilization was not identified.…”

Concentrations of TENORMs in the petroleum industry and their environmental and health effects

“…These wastes contain high levels of salts such as barium, benzene, etc., 244 which are rich in radionuclides, where the liquid part of the waste is ltered to the ground water, causing serious radioactive contamination. 232,[245][246][247][248] Impact on surface water. 8,138,225,249 All effluents from the oil and gas industry such as produced water, washing water for rigs, drilling machines, maintenance and repair, oil grease contaminated water, liquid sludge, etc., may contain radioactive materials.…”