Beneath the Surface: Unraveling the Environmental Risks of Shale Gas Development

A recent blowout at a shale gas well in Pennsylvania illustrates that natural gas, while offering promising potential for reducing pollution in a carbon-constrained economy, comes with serious environmental and health risks.

The accident caused no injuries, but it came amid a series of less spectacular environmental incidents associated with natural gas development in recent months. The Pennsylvania blowout was a graphic reminder that better worker training and closer adherence to industry best practice and state regulations are essential if the recent boom in gas development is to be sustained.

Two weeks ago, Worldwatch’s Natural Gas and Sustainable Energy Initiative released the second in a series of briefing papers examining the role of natural gas in a low-carbon energy economy. In the report, we conclude that water contamination and dangerous blowouts in shale gas wells can be avoided if drilling wells and wastewater reservoirs are regulated more stringently.

In the Initiative’s first briefing paper, published in April, we laid out some of the opportunities and challenges that natural gas presents to a carbon-constrained world. Many of the new opportunities, including the potential to reduce power-sector emissions by displacing coal and facilitate the greater penetration of variable renewable energy, depend on a secure, affordable supply of natural gas. The latest estimates suggest that this could come from large organic-rich shale formations lying deep below large sections of the United States.

But developing these resources will bring gas drilling to new regions and at larger scales, raising questions about the risks that development poses to communities and the environment. In our latest briefing paper, “Addressing the Environmental Risks from Shale Gas Development,” co-authored with Stanford University geophysicist Mark Zoback and Environmental Defense Fund’s Brad Copithorne, we look at what really occurs in the Earth’s subsurface during horizontal drilling and hydraulic fracturing. The evaluation assesses the risks to local water quality and the environment and discusses some of the technologies, best practices, and regulations needed to minimize those risks.

After reviewing the techniques involved in extracting shale gas, as well as documented cases of environmental problems linked to shale gas development, we conclude that the greatest risk of groundwater contamination, blowouts, and surface water contamination comes from two sources: faulty well construction and above-ground leaks and spills of fracturing fluids or wastewater. Continued study and improved communication of the environmental risks associated with both individual wells and large-scale shale gas development are essential for society to make well-informed energy choices.

Many technologies and best practices that can minimize the environmental and health risks are already being used by some companies, and more are being developed. In addition, state regulatory agencies are responsible for ensuring environmental protection through their permitting processes and regulations. Nevertheless, regulatory capacity and regulations themselves can vary significantly from state to state, and both will need to be improved in many states if shale gas is to contribute to a low-carbon economy.

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