SAN JOSE STATE UNIVERSITY
Freshwater resources around the world are under threat from fossil fuel development, and these threats are emerging in new places with the rapid growth in recent years of natural gas extraction from shale using horizontal drilling and hydraulic fracturing. This technique has been criticized for its environmental impacts, including dewatering streams and surface- and groundwater pollution. Many specific instances of water impacts remain under scientific investigation, and in Pennsylvania and West Virginia, a number of researchers have documented the potential impacts of fracking on water resources.
This report focuses on the extraction of natural gas from the Marcellus Shale in Pennsylvania and West Virginia. While conventional gas production has been conducted here for decades, unconventional wells that utilize advances in horizontal drilling have grown considerably more common in the past decade. Nearly nine thousand horizontal Marcellus Shale natural gas wells have been permitted in these two states from 2005 to 2012, and more than eleven thousand such wells will likely be permitted by the end of 2013.
As permitted wells have been developed and started production, they have drastically increased gas production in these two states. These wells have also made an important contribution by growing the regional workforce and contributing to state taxes, a significant economic benefit during a time of economic stagnation.
In recent years, West Virginia and Pennsylvania have improved their regulation and oversight of water use and pollution from natural gas extraction. Both states now require recordkeeping and public reporting of key water quality and quantity information. In this report, we use these databases to document water withdrawals, fluid injections, and waste recovery and disposal, including the transport of waste to neighboring states. We also apply the concept of life cycle analysis to calculate the water footprint of the extraction phase of natural gas from Marcellus Shale.
In addition, we provide recommendations for improving data collection and reporting requirements to appropriately inform future management decisions by policy makers, regulators, and operators. More broadly, these recommendations will help regulators—and the industry itself—ensure that water withdrawals, fluid injection, and waste disposal are undertaken in such a manner as to protect the region’s groundwater and surface water resources.
Key West Virginia findings
- Approximately 5 million gallons of fluid are injected per fractured well.
- Surface water taken directly from rivers and streams makes up over 80% of the water used in hydraulic fracturing and is by far the largest source of water for operators. Because most water used in Marcellus operations is withdrawn from surface waters, timing is important, and withdrawals during low flow periods can result in dewatering and severe impacts on small streams and aquatic life.
- Reused flowback fluid accounts for approximately 8% of water used in hydraulic fracturing.
- On average, only 8% of injected fluid is recaptured. The remaining 92% remains underground, completely removed from the hydrologic cycle.
- The flowback fluid reported as waste in West Virginia represents only approximately 38% of total waste volume. Because of inadequate state reporting requirements, the fate of 62% of fracking waste is unknown.
- At present, the three-state region—West Virginia, Pennsylvania, and Ohio—is tightly connected in terms of waste disposal. Almost one-half of flowback fluid recovered in West Virginia is transported out of state. Between 2010 and 2012, 22% of recovered flowback fluid was sent to Pennsylvania, primarily to be reused in other Marcellus operations, and 21% was sent to Ohio, primarily for disposal via underground injection control wells.
- The amount of water used per well is higher than previously estimated for Marcellus Shale wells. The blue water footprint of wells started in West Virginia from 2010 to 2012, which represents the volume of water removed from the hydrologic cycle per unit of gas produced, ranges from 1.6 to 2.2 gallons/Mcf. When considering the sensitivity of these results to higher gas production estimates, the range dropped to 1.2 to 2.0. Previous estimates of water use ranged from 0.677 to 1.2.
Key Pennsylvania findings
- Approximately 4.3 million gallons of fluid are injected per fractured well.
- On average, only 6% of injected fluid is recaptured. The remaining 94% remains underground, permanently removed from the hydrologic cycle.
- In Pennsylvania, three primary waste categories are tracked: flowback fluid, brine, and drilling waste, with flowback fluid representing approximately 38% of the total.
- As Marcellus development has expanded, waste generation has increased. In Pennsylvania, operators reported an almost 70% increase in waste generated from 2010 to 2011—rising to a reported 613 million gallons of waste in 2011.
- More than 50% of waste generated by Pennsylvania Marcellus wells is treated and discharged to surface waters—either through brine/industrial waste treatment plants or municipal sewage treatment plants. This stands in stark contrast to West Virginia, where virtually no flowback fluid is reported to be discharged to surface waters.
- In Pennsylvania, approximately one-third of total waste is reused, although data are not available to determine whether it is reused in Pennsylvania or elsewhere. Approximately 5% of total Pennsylvania Marcellus waste is injected in UIC wells, mostly in Ohio.
- There is significant potential for Marcellus development in Pennsylvania to impact water quality because a large percentage of waste is treated at plants that discharge to the state’s rivers and streams.
- At present, the three-state region— West Virginia, Pennsylvania, and Ohio—is tightly connected in terms of waste disposal. While most Pennsylvania waste remains in-state, a significant amount of waste is shipped to UIC wells in Ohio, and Pennsylvania reuses flowback fluid received from West Virginia.
- In Pennsylvania, the blue water footprint, which represents the volume of water removed from the hydrologic cycle per unit of gas produced, ranges from 3.2 to 4.2 gallons per Mcf from 2009 to 2011 on a 4-year production basis. When considering the sensitivity of these results to higher natural gas estimates, the range dropped to 1.2 to 3.9. Previous estimates of water use ranged from 0.677 to 1.2.
About Downstream Strategies
“We have considerable background in environmental science and policy, Geographic Information Systems, field monitoring, watershed planning, chemistry, permitting, and acid mine drainage treatment design. Our skills also include environmental economics and survey design and execution. We have an established track record of managing successful projects from inception to completion.”
About the San Jose State University Department of Environmental Studies
“Founded in 1970, the focus of the Environmental Studies Department is on a rigorous, systematic, and integrated approach to the study, management, and solution of environmental challenges. Upon completion of the degree, students have a solid preparation for making substantial contributions to this expanding and vital field.”