Framework for Examining Stream Ecosystem Health in Areas of Shale Gas Development—A Multi-Parameter Watershed-Based Case Study in Pennsylvania Completed
Macroinvertebrates are Important Components of Aquatic Ecosystems
In a case study of 25 headwater streams in Pennsylvania, no statistically significant associations were determined between shale gas development and geochemical tracers of produced waters or measures of microbial and macroinvertebrate community composition. Although the results are specific to the region studied, the integrated biological and geochemical framework provides a tool for examining effects of energy development in other watersheds with differing size, land cover, or best management practices.
The development of horizontal drilling and high-volume hydraulic fracturing techniques to extract natural gas from shale formations has matured over the past decade, leading to a rapid expansion in the development of this resource. This increase in shale gas development has been especially notable for the Marcellus Formation in Pennsylvania, where gas production has increased from 193 billion cubic feet in 2006 to 5,500 billion cubic feet by 2017, accounting for nearly 20 percent of total natural gas production in the United States according to the Energy Information System Administration. As the activities associated with shale gas development have expanded rapidly, so have questions about the potential for changes in water chemistry and health risks to biota in nearby stream ecosystems.
Previous research has indicated the potential for various aspects of oil and gas production (unintentional releases of hydraulic fracturing fluid and wastewater, erosion and sedimentation from the construction and operation of well pads, and installation of pipelines and roads) to affect nearby headwater stream ecosystems and other water resources. However, the ability to generalize the results from these studies is limited by the small geographic scope as well as limited breadth and integration of measured chemical and biological parameters.
Scientists from the U.S. Geological Survey Environmental Health Energy Science Team collaborated with the Pennsylvania Department of Conservation of Natural Resources and the Pennsylvania Department of Environmental Protection to understand if the intensity of shale gas development in a watershed was associated with increased stream-water concentrations of known geochemical tracers of gas extraction (for example sodium, chloride, lithium, barium, and bromide), and changes in the composition of benthic macroinvertebrate and sediment microbial communities.
The team sampled 25 headwater streams in Pennsylvania State forests that drain lands with varying degrees of shale gas development intensity. Recreation and timber harvesting have been the primary land uses since the early to mid-1900s thus providing an opportunity to study the effect of shale gas development in an environment with few other potential stressors.
To select sites, watersheds within the Pennsylvania State forest system were scored and categorized based on a gradient of shale gas development intensity, then five sites were randomly selected from each assigned category. The development of intensity scores was based on a previously designed geospatial index with 17 measures that incorporate all steps in oil and gas development, including infrastructure, well drilling and stimulation, and production. The sampling strategy included measurements of multiple hydrologic, geochemical, and biological parameters across multiple seasons of sampling in 2016 and 2017 to account for temporal variability.
This study reported that geochemistry of the streams varied seasonally and corresponded to changes in streamflow; however, there were no definitive geochemical indications of hydraulic fracturing fluid or produced water in any of the study streams. Streambed microbial diversity and the number of sensitive macroinvertebrate taxa (Ephemeroptera, Plecoptera, and Trichoptera), overall invertebrate diversity, and Index of Biotic Integrity scores did not differ between years or differ based on shale gas intensity index.
Overall, no statistically significant associations could be determined between shale gas development intensity and geochemical tracers of produced waters or measures of microbial and macroinvertebrate community composition in the watersheds studied. Although these results are specific to the watersheds studied and cannot be extrapolated elsewhere, the integrated biological and geochemical approach provides a framework to examine whether there are effects of energy development in other watersheds with differing size, land cover, or best management practices. This integrated, multiparameter study is part of the USGS Environmental Health Energy Science Team’s overall approach to assess if there are health effects to humans and wildlife because of exposures to energy production materials or activities in the environment.
The USGS Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology Programs combined), the Pennsylvania Department of Conservation and Natural Resources Shale Gas Monitoring Program, and the Pennsylvania Department of Environmental Protection provided funding for this work.
Reference
Mumford, A., Maloney, K.O., Akob, D.M., Nettemann, S., Proctor, A., Ditty, J., Ulsamer, L., Lookenbill, J., and Cozzarelli, I., 2020, Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multi-parameter study in Pennsylvania: PNAS, v. 117, no. 7, p. 3670-3677, https://doi.org/10.1073/pnas.1911458117.
Below are other science projects associated with this project.
Examining Shifts in Stream Microbial Communities Exposed to Oil and Gas Wastewaters
Understanding Pathways of Unconventional Oil and Gas Produced Water Spills in the Environment
Indication of Unconventional Oil and Gas Wastewaters Found in Local Surface Waters
Fate and Effects of Wastes from Unconventional Oil and Gas Development
Microbiology and Chemistry of Waters Produced from Hydraulic Fracking—A Case Study
Below are publications associated with this project.
Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multiparameter study in Pennsylvania
The number of horizontally drilled shale oil and gas wells in the United States has increased from nearly 28,000 in 2007 to nearly 127,000 in 2017, and research has suggested the potential for the development of shale resources to affect nearby stream ecosystems. However, the ability to generalize current studies is limited by the small geographic scope as well as limited breadth and integration o
A detailed risk assessment of shale gas development on headwater streams in the Pennsylvania portion of the Upper Susquehanna River Basin, U.S.A.
- Overview
In a case study of 25 headwater streams in Pennsylvania, no statistically significant associations were determined between shale gas development and geochemical tracers of produced waters or measures of microbial and macroinvertebrate community composition. Although the results are specific to the region studied, the integrated biological and geochemical framework provides a tool for examining effects of energy development in other watersheds with differing size, land cover, or best management practices.
The development of horizontal drilling and high-volume hydraulic fracturing techniques to extract natural gas from shale formations has matured over the past decade, leading to a rapid expansion in the development of this resource. This increase in shale gas development has been especially notable for the Marcellus Formation in Pennsylvania, where gas production has increased from 193 billion cubic feet in 2006 to 5,500 billion cubic feet by 2017, accounting for nearly 20 percent of total natural gas production in the United States according to the Energy Information System Administration. As the activities associated with shale gas development have expanded rapidly, so have questions about the potential for changes in water chemistry and health risks to biota in nearby stream ecosystems.
Previous research has indicated the potential for various aspects of oil and gas production (unintentional releases of hydraulic fracturing fluid and wastewater, erosion and sedimentation from the construction and operation of well pads, and installation of pipelines and roads) to affect nearby headwater stream ecosystems and other water resources. However, the ability to generalize the results from these studies is limited by the small geographic scope as well as limited breadth and integration of measured chemical and biological parameters.
Scientists from the U.S. Geological Survey Environmental Health Energy Science Team collaborated with the Pennsylvania Department of Conservation of Natural Resources and the Pennsylvania Department of Environmental Protection to understand if the intensity of shale gas development in a watershed was associated with increased stream-water concentrations of known geochemical tracers of gas extraction (for example sodium, chloride, lithium, barium, and bromide), and changes in the composition of benthic macroinvertebrate and sediment microbial communities.
The team sampled 25 headwater streams in Pennsylvania State forests that drain lands with varying degrees of shale gas development intensity. Recreation and timber harvesting have been the primary land uses since the early to mid-1900s thus providing an opportunity to study the effect of shale gas development in an environment with few other potential stressors.
To select sites, watersheds within the Pennsylvania State forest system were scored and categorized based on a gradient of shale gas development intensity, then five sites were randomly selected from each assigned category. The development of intensity scores was based on a previously designed geospatial index with 17 measures that incorporate all steps in oil and gas development, including infrastructure, well drilling and stimulation, and production. The sampling strategy included measurements of multiple hydrologic, geochemical, and biological parameters across multiple seasons of sampling in 2016 and 2017 to account for temporal variability.
This study reported that geochemistry of the streams varied seasonally and corresponded to changes in streamflow; however, there were no definitive geochemical indications of hydraulic fracturing fluid or produced water in any of the study streams. Streambed microbial diversity and the number of sensitive macroinvertebrate taxa (Ephemeroptera, Plecoptera, and Trichoptera), overall invertebrate diversity, and Index of Biotic Integrity scores did not differ between years or differ based on shale gas intensity index.
Overall, no statistically significant associations could be determined between shale gas development intensity and geochemical tracers of produced waters or measures of microbial and macroinvertebrate community composition in the watersheds studied. Although these results are specific to the watersheds studied and cannot be extrapolated elsewhere, the integrated biological and geochemical approach provides a framework to examine whether there are effects of energy development in other watersheds with differing size, land cover, or best management practices. This integrated, multiparameter study is part of the USGS Environmental Health Energy Science Team’s overall approach to assess if there are health effects to humans and wildlife because of exposures to energy production materials or activities in the environment.
The USGS Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology Programs combined), the Pennsylvania Department of Conservation and Natural Resources Shale Gas Monitoring Program, and the Pennsylvania Department of Environmental Protection provided funding for this work.
Reference
Mumford, A., Maloney, K.O., Akob, D.M., Nettemann, S., Proctor, A., Ditty, J., Ulsamer, L., Lookenbill, J., and Cozzarelli, I., 2020, Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multi-parameter study in Pennsylvania: PNAS, v. 117, no. 7, p. 3670-3677, https://doi.org/10.1073/pnas.1911458117.
- Science
Below are other science projects associated with this project.
Examining Shifts in Stream Microbial Communities Exposed to Oil and Gas Wastewaters
Shifts in the overall microbial community structure were present in stream sediments that contained chemicals associated with unconventional oil and gas wastewaters. This work is part of a long-term study designed to understand persistence of chemicals from oil and gas wastewaters in sediments and water and how those factors might be related to exposures and adverse health effects, if any, on...Understanding Pathways of Unconventional Oil and Gas Produced Water Spills in the Environment
A new study measures the transport of chemicals associated with unconventional oil and gas (UOG) produced waters downstream from a pipeline leak in North Dakota. This work is part of a long-term study designed to understand chemical persistence in sediments and water and how those factors might be related to contaminant exposures and associated with adverse health effects, if any, on organisms.Indication of Unconventional Oil and Gas Wastewaters Found in Local Surface Waters
Evidence indicating the presence of wastewaters from unconventional oil and gas (UOG) production was found in surface waters and surficial sediments near an UOG disposal facility in West Virginia.Fate and Effects of Wastes from Unconventional Oil and Gas Development
This study is assessing the environmental health risks associated with wastes from unconventional oil and gas development by characterizing waste materials, identifying potential environmental pathways, and evaluating the potential effects on organisms from exposure to unintended waste releases.Microbiology and Chemistry of Waters Produced from Hydraulic Fracking—A Case Study
A new U.S. Geological Survey (USGS) study determined that the microbiology and organic chemistry of produced waters varied widely among hydraulically fractured shale gas wells in north-central Pennsylvania. - Publications
Below are publications associated with this project.
Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multiparameter study in Pennsylvania
The number of horizontally drilled shale oil and gas wells in the United States has increased from nearly 28,000 in 2007 to nearly 127,000 in 2017, and research has suggested the potential for the development of shale resources to affect nearby stream ecosystems. However, the ability to generalize current studies is limited by the small geographic scope as well as limited breadth and integration o
AuthorsAdam Mumford, Kelly O. Maloney, Denise M. Akob, Sarah Nettemann, Arianne Proctor, Jason Ditty, Luke Ulsamer, Josh Lookenbill, Isabelle M. CozzarelliA detailed risk assessment of shale gas development on headwater streams in the Pennsylvania portion of the Upper Susquehanna River Basin, U.S.A.
The development of unconventional oil and gas (UOG) involves infrastructure development (well pads, roads and pipelines), well drilling and stimulation (hydraulic fracturing), and production; all of which have the potential to affect stream ecosystems. Here, we developed a fine-scaled (1:24,000) catchment-level disturbance intensity index (DII) that included 17 measures of UOG capturing all stepsAuthorsKelly O. Maloney, John A. Young, Stephen Faulkner, Atesmachew Hailegiorgis, E. Terrence Slonecker, Lesley Milheim