The Marcellus Shale formation extends from southern New York across Pennsylvania and into western Maryland, West Virginia, and eastern Ohio. Media coverage of Marcellus Shale natural gas development over the past year has been difficult to miss. Concerns about speed of development, air emissions, and regulatory oversight have sparked controversy over the development of this gas play. This article briefly reviews recent key environmental actions in Pennsylvania. References to internet resources are provided for those who are interested in obtaining more details.

Active development of Marcellus Shale resources in Pennsylvania began several years ago. Since approximately 2008, Pennsylvania regulators have increased supervision of natural gas operations through increasing oversight, doubling the number of oil and gas inspection staff, and implementing new water quality standards and other regulatory changes.

The Pennsylvania Department of Environmental Protection (PA DEP) and the Pennsylvania Environmental Quality Board (PA EQB) recently enacted changes to improve well completion practices and protect surface and groundwater in Chapter 78 of the Pennsylvania Code governing oil and gas wells. These changes concern 1) casing and cementing wells, 2) restoration or replacement of water wells affected by drilling, 3) operator obligations for well control, response to gas migration complaints, and inspection of existing wells, and 4) access to pre-drilling water testing results. Further details are available at

The PA EQB also implemented changes to regulations for surface discharges of treated wastewater. Pennsylvania historically had permitted surface discharge of treated wastewater from natural gas operations. The revised rules prohibit publicly owned treatment works (POTW) in the Commonwealth from receiving wastewater from natural gas operations unless the wastewater has first been treated at a centralized wastewater treatment (CWT) facility to the rigorous standards set by the new rules. The new rules exempt existing, permitted wastewater discharges by facilities which already were accepting oil and gas wastewater, provided they continued to process that water at their permit levels. These rules are published at Additional information concerning PA DEP’s oversight and regulation of Marcellus Shale operations is available at

In April 2011, PA DEP Secretary Michael Krancer requested that by May 19, 2011, Marcellus Shale natural gas operators stop sending wastewater from shale gas extraction to wastewater treatment facilities. This request was an effort to address the new regulations’ exemption of existing surface water discharges by “grandfathered” POTWs. Measurements of elevated bromide levels in surface water in Western Pennsylvania prompted this effort to stop operators from sending any shale gas wastewater to wastewater treatment plants. Operators in Pennsylvania have complied with the request, accelerating efforts to develop wastewater recycling methods and alternative disposal options.

In March 2011, Pennsylvania Governor Tom Corbett issued an executive order forming the Marcellus Shale Advisory Commission to propose a strategy for the “responsible and environmentally sound development of Marcellus Shale.” The Commission, chaired by Lieutenant Governor Jim Cawley, included members from the environmental, conservation, state and local government, academic and natural gas industry communities. Following a series of public meetings, and a broad review of Marcellus Shale issues, the Commission issued its final report on July 22, 2011. For additional information regarding the Commission and its report, go to This website includes links to many useful resources, including rules and regulations governing Marcellus Shale operation in Pennsylvania. The draft recommendations submitted by Commission members provide insight into the myriad issues and perspectives on development of Marcellus Shale resources within the Commonwealth.

On October 3, 2011, Governor Corbett announced a plan, drawing heavily from his Commission’s recommendations, for strengthening regulatory requirements for well placement in relationship to water wells and surface waters, increased amounts for bonds for wells, increased penalties for environmental violations, and an annual impact fee to be assessed by counties where drilling occurs. Additional information regarding Governor Corbett’s proposal is available at

Most recently, the PA DEP released a technical guidance document addressing, among other things, whether two or more oil and gas stationary air emissions sources should be aggregated and treated as a single source for air permitting purposes. Because very few individual oil and gas well sites have sufficient emissions to surpass major source thresholds on their own, advocacy groups have urged regulatory agencies to aggregate multiple, individual operations so that they require Prevention of Significant Deterioration (PSD) or Nonattainment New Source Review (NSR) and Title V permits. At first glance, the guidance takes a mostly common-sense approach concerning the key issues of when two sources are “contiguous” or “adjacent” so as to be eligible for aggregation. PA DEP will consider sites one-quarter mile or less apart to be contiguous or adjacent and will consider more distant sites on a case-by-case basis. For many operators, the guidance likely will not result in significant aggregation, making it likely that advocacy groups will file comments seeking more aggressive interpretation. Nonetheless, use of and enforcement based on the guidance will have the most impact on natural gas processing operations and will result in more stringent emissions control and reduction standards. Companies should evaluate their operations and provide comments to PA DEP that articulate where the agency’s “common sense” and the company’s actual operations do and do not align. The Technical Guidance on Air Aggregation for Oil and Gas Industries is available at

The PA DEP is accepting comments on its technical guidance until November 21, 2011.