Assessing Potential Effects of Hydraulic Fracturing for Energy Development on Water Resources
Production of oil and gas from “unconventional” plays (low-permeability reservoirs of shale gas, shale oil, and tight-sands gas) is increasing in the United States. Extracting hydrocarbons from an unconventional play requires increasing its permeability by hydraulic fracturing. This requires large volumes of water and involves various chemical additives, penetration of aquifers, and waste-product disposal. With increased unconventional domestic oil and gas production, there is also increasing public concern regarding the potential effects of hydraulic fracturing on surface-water and groundwater quality. However, there is little scientifically based information on potential effects of hydraulic fracturing on water resources.
To help fill this data gap, an interdisciplinary team of three USGS scientists, including FORT scientist Zack Bowen, received a grant from the U.S. Geological Survey’s Powell Center for Analysis and Synthesis to lead the first broad-scale, data-based assessment of water quality in areas where unconventional oil and gas development is occurring. The team initiated the project by hosting a scoping workshop attended by 29 scientists representing 14 USGS water science centers, the National Center, the National Research Program, the Central Energy Resources Center, the Central Region National Water-Quality Assessment Program, FORT, the Columbia Environmental Research Center, Duke University, and an eastern Colorado water conservation district. Participants presented their expertise and interest as it relates to this project, then identified possible approaches for using existing high-quality, robust databases for examining possible effects of hydraulic fracturing on water resources.
A core team of 12 people was formed to conduct the analyses, syntheses, and product development. The team has pulled national water-quality data, by unconventional play, from the USGS National Water Information System database and the Environmental Protection Agency (EPA) STORET data warehouse. These data represent a total of 344 groundwater wells and 16,752 stream gages. The team also identified potential project products and developed a product-development schedule. Planned products include:
a data report summarizing data used in the analyses, and
a high-impact journal article detailing important findings of this project.
The products will target a range of audiences, from policymakers and agencies charged with regulating activities that potentially impact water resources (e.g., the EPA, state- and watershed-level boards or commissions), to other scientists and potential clients seeking to address related questions, to the general public. It is expected that results of the analyses will provide an assessment of the quality of surface water and groundwater in areas of unconventional oil and gas production and help to identify areas of research needed to better address questions regarding effects of hydraulic fracturing on U.S. water resources.
Feeding Ecology of Insect-eating Bats
A field of wind turbines at dusk
A hoary bat
Bats are the only flying mammals that are active mostly at night and occur on all continents except Antarctica. Bats are ecologically diverse, with a range of species that specialize in feeding on fruit, nectar, blood, fish, small mammals, and insects. However, of the more than 1,100 known species of bats on Earth, the majority specialize in feeding on insects (are insectivorous). In the United States for example, of the 45 different species of bats, 42 are insectivorous. These small creatures of the night are diverse in shape and size, with most relying on echolocation to detect insect prey and find their way through darkness. Many of these bats form colonies that feed on seasonally available insects from spring to autumn. Most insectivorous bats use this seasonal feeding strategy to help build fat reserves during the summer and autumn, prior to their hibernation during winter - a time, generally, when insects are not available throughout most of the United States. Some of these bat species do not hibernate but instead migrate seasonally. It is believed that the timing of migration and routes that they take, such as those for the hoary bat (Lasiurus cinereus), might coincide with availability of their preferred insect prey.
Recently, many of these insectivorous bat species have suffered drastic declines in numbers due to new environmental stressors, both natural and human caused. One of these stressors is the emerging wildlife disease known as white-nose syndrome (WNS). This disease is caused by the fungus Pseudogymnoascus destructans and has been devastating colonies of hibernating bats in the eastern United States for several years. At present, there is no known cure for WNS, which continues to spread north-, south-, and westward. It is likely that the effects of declining insectivorous bat populations will influence insect populations, including possible increases, in some geographic areas of insects that are economic pests.
Like WNS, the development of alternative energy in the form of industrial wind energy facilities is also having a harmful effect on bats through collisions with moving turbine blades. These fatal encounters often coincide with the autumn migration of bats. Why certain bats are susceptible to turbines remains unknown, yet feeding on insects may play a role in bat susceptibility. For example, the hoary bat is killed more often than any other species of bat at wind turbines in North America, and it is believed that certain prey types (e.g., noctuid moths) consumed by these bats may be locally and seasonally abundant around wind energy facilities.
Despite the high species and ecological diversity of insectivorous bats in the United States, little information exists on their diet. At FORT, biologists are investigating dietary habits of insectivorous bats, which will help provide insight into questions related to climate change, energy development, wildlife diseases, and conservation.
Effects of Energy Development in the Rocky Mountain Area (EERMA)
Increased demand for energy is driving rapid development of oil and gas (including shale gas and coal-bed methane), uranium, geothermal, wind, and solar sources of energy throughout the western United States. Much of the development is occurring on public lands, including those under Federal and State jurisdictions. In Colorado and New Mexico, these public lands make up about 40 percent of the land area. Both of these states benefit from revenues generated by energy development, but resource managers and other decisionmakers must balance the benefits with their potential effects on historic, scenic, recreational, and ecological resources. Although past studies have assessed some effects of energy development, the information has not yet been synthesized to make it useful to decisionmakers and resource managers.
To address this need, an interdisciplinary team of USGS scientists is developing a multi-step analytical process, or framework, for estimating the outcomes and cumulative impacts of energy development in Colorado and New Mexico. The science team includes Tasha Carr of FORT, Jay Diffendorfer of the Rocky Mountain Geographic Science Center, Natalie Latysh in Core Science Systems, Ken Leib of the Colorado Water Science Center, Anne-Marie Matherne of the New Mexico Water Science Center, and Sarah Hawkins with the Central Energy Resources Science Center. Their work entails (1) assessing agency information needs; (2) compiling information from USGS assessments of non-renewable energy resources as a basis for estimating potential development of energy resources; and (3) assimilating baseline data on current energy development—both renewable and non-renewable—for projecting characteristic “footprints” and life-cycle for each energy type to similar areas with the potential for energy development. All the spatial information will be made available to end users in the form of an online, interactive energy atlas. Combined, the framework, analytical tools, and energy atlas will be valuable to decisionmakers and resource managers in their endeavors to anticipate energy development scenarios in Colorado and New Mexico, evaluate the associated consequences, and develop appropriate mitigation strategies.
Development of Mineral Environmental Assessment Methodologies: Wyoming Landscape Conservation Initiative
This work involves developing and testing mineral-environmental assessment methods in the Wyoming Landscape Conservation Initiative (WLCI) area of Southwestern Wyoming to understand the environmental effects of energy production on watersheds. The assessment methods will be tailored to help address high-priority issues of interest in the area, as determined through discussions with WLCI scientists.
Development of Mineral Environmental Assessment Methodologies: Prototype Regional Mineral Environmental Assessment
This project involves three related tasks. The first involves developing geospatial information to better aid regional-scale assessment of the effects of minerals on the environment. This information can be used by natural resource managers to better understand how development and extraction of mineral deposits might affect the environment. In the second task, USGS scientists are developing measures of ecosystem health and function based on aquatic community interactions with mineralized areas. Resource managers can use this information to understand how aquatic ecosystems are affected by mineralized systems. The third task entails developing the use of geoenvironmental models for use with ecological risk-assessment methodologies to improve understanding of the effects of geologic processes on aquatic ecosystems.
Wyoming Conservation Landscape Initiative: Inventory and Long-Term Monitoring
Green River Valley, Wyoming. WLCI photo.
Across Southwest Wyoming, there is increasing concern that energy development and climate change will significantly alter the region’s habitats, thus putting the region’s world-class wildlife populations at risk of decline. To provide accurate condition estimates across a large region, and to subsequently monitor changes in conditions, a representative sample of resources is required. This landscape, like most, is highly variable due to differences in natural and anthropogenic environmental factors, such as topography, climate, and land-use. To this end, we are (1) investigating application of landscape-scale framework for assessing status and trends in resource conditions; (2) characterizing potential “indicators” that have properties conducive to monitoring and also representative of habitat conditions and ecosystem function; and (3) developing fine-scale mapping and change–detecting, remote sensing techniques for vegetation. We are working with partners to develop a monitoring framework that provides the spatial representation required for measuring the condition of priority habitats, wildlife populations, ecosystems, and related variables across this large and varied landscape. On-the-ground data collection, model simulations, and statistical analyses of the power of selected indicators will be conducted to test the potential of sampling designs to meet long-term monitoring objectives for Southwest Wyoming. Providing direct support for affordable monitoring, the remote sensing work contributes to developing methods to repeatedly project estimates of continuous vegetation cover, with separation of major vegetation types. Using both field-collected and remotely sensed data, we will evaluate variability in these habitat measures and how they change over time. Combined, the different elements of this task will help natural resource managers and policymakers amass the multiple levels of information needed to understand the collective condition of Southwest Wyoming’s public lands, and to apply that information for better conserving habitats and wildlife populations in the face of significant changes.
Wyoming Landscape Conservation Initiative: Mechanistic Studies of Wildlife
Rapid energy development and other human-caused disturbances in southwestern Wyoming are challenging the abilities of natural resource managers to ensure persistence of the region’s vast diversity of wildlife. Prior studies of greater sage-grouse (Centrocercus urophasianus) and pygmy rabbits (Brachylagus idahoensis) indicate populations in Wyoming are declining, likely due to loss and fragmentation of sagebrush habitats, and both species were considered for listing through the Endangered Species Act within the past two years. To help address population declines, we are (1) developing spatial models to assess how sage-grouse respond to habitat changes associated with energy development and climate change across large landscapes; (2) analyzing long-term population trends of sage-grouse across Wyoming to identify mechanisms (specifically those associated with climate and energy development) that may influence population fluctuations; and, (3) developing predictive habitat-selection models. Less information exists for pygmy rabbit populations. To help provide information about pygmy rabbits, we are (1) validating two existing spatial models that predict occupancy across Wyoming with the Wyoming Natural Diversity Database and the Wyoming Chapter of The Nature Conservancy ; (2) developing a new model that predicts both site occupancy and vacancy using landscape-level habitat attributes, including factors associated with energy development, sagebrush vegetative structure, and updated climate information; (3) beginning two studies to evaluate occupancy and survival rates on three major gas fields in western Wyoming; and (4) relating occupancy data with LiDAR data that describes the structural characteristics of sagebrush over broad areas. Combined, the efforts of this work will provide the information and tools needed to help natural resource managers and policymakers develop effective wildlife management plans for sage-grouse, pygmy rabbits, and other species in southwestern Wyoming.