Part 2: What Do We Want the Legacy of Shale Gas to Be?

Cover of report: Potential environmental impacts of full-development of the Marcellus Shale in Pennsylvania

In my last post, I wrote about a new report from The Nature Conservancy and Carnegie Mellon University that discusses the next generation of environmental practices for shale gas development.  An important new analysis from CNA, a nonprofit research organization that operates the Center for Naval Analyses and the Institute for Public Research, provides the basis for understanding how important those next-gen practices are.

The Potential Environmental Impacts of Full Development of the Marcellus Shale in Pennsylvania looks at what would result from the development of all remaining technically recoverable resources in the Marcellus shale.

The report presents a rich set of maps depicting the results of the analysis:

  • Well development projections
    • 47,600 additional wells could be developed on 5,950 well pads over the next 30 years  
  • ​​Impact to forests and land
    • Over 100,000 acres of core forest would be lost due to the combined effect of clearing and fragmentation.
    • The construction of well pads, gathering pipelines, and access roads would result in about 94,000 acres of additional land disturbance – about 51,000 acres impacting agricultural land, and about 28,000 acres impacting forest cover.
  • Impacts to population
    • The population in Pennsylvania living within one-half mile of a well pad could increase from about 100,000 today to 639,000.
    • The population living within one mile of a well pad could increase from about 311,000 today to over 1.8 million at full build-out.  
  • Air emissions
    • Nitrogen Dioxide (NOx) emissions could increase from current 21,622 tons per year to 37,000 tons per year
    • Volatile Organic Compound (VOC) emissions would more than triple from current 6,388 tons per year to 22,500 tons per year
    • Methane emissions could more than triple from 107,492 tons per year to 388,000 tons per year. It’s important to understand that the current methane emission figure is based on industry self-reporting and, as I noted here, is suspect at best. A potential 370% increase in what is perhaps a very understated amount of methane emissions underscores the critical importance of enacting Pennsylvania’s nation-leading methane emissions reduction strategy
  • Water and wastewater impacts – The analysis is heavily qualified, and provides only projections; unfortunately, it does not estimate total current use rates:
    • A projected average 22 million gallons per day of water used for drilling, 84% of which would be lost to the hydrologic cycle.
    • An average of 7.65 million gallons per day of wastewater generated.

As noted in the report’s Executive Summary:

…these aggregated metrics do not tell the full story of the impacts, which have important geographic variations. Thus, the primary output of this research is an atlas: a set of maps that puts the impacts of the projected natural gas development into useful spatial context. These maps, and the data developed to generate them, present useful information to policy-makers, decision-makers, and other researchers concerned about managing the range of impacts of shale gas extraction in Pennsylvania.

Given this CNA analysis and the TNC/CMU report, it’s appropriate to ask again:  What do we want the legacy of shale gas to be?

John Quigley

Senior Fellow, Kleinman Center
John Quigley is a senior fellow at the Kleinman Center and previously served on the Center’s Advisory Board. He served as Secretary of the PA Department of Environmental Protection and of the PA Department of Conservation and Natural Resources.