Natural gas trapped in shale rock formations is an important energy resource in the United States. Large deposits have been found in several areas of the US, including Texas, North Dakota, and Pennsylvania. Natural gas burns much cleaner and releases less carbon into the atmosphere when compared to other fossil fuels, making it an ideal fuel for use in cars and power plants. Because the rock formation can be as much as 10,000 feet below the surface, advanced drilling techniques must be used in order to access them. The recent innovation of horizontal drilling coupled with hydraulic fracturing has significantly improved the ability of drillers to access gas in shale rock formations. These techniques can have an impact on the environment if not properly handled.
Below is a brief summary of some of the environmental issues surrounding shale gas development:
Hydraulic fracturing requires large amounts of water, and in some areas this can put pressure on natural ecosystems or industries in which clean water is required.
Waste water from gas production contains natural contaminants and chemicals which require the water either be treated at an appropriate facility or disposed of by deep-well injection. Some feel that the large amounts of waste water may have a negative effect on water ways or groundwater through seepage or spills. There are multiple protections to ensure that this does not happen, required by both regulators and the industry, making these events few and far between.
There are concerns about the use of fossil fuels contributing carbon and other substances in to the environment. As stated above, natural gas in one of the cleanest burning fossil fuels, and can help us to reduce air-quality issues while meeting our energy needs. “Flaring”, or the burning off of natural gas, occurs during the first few days of production of a gas well until pressures have stabilized and infrastructure is in place to capture it.
Environmental groups opposed to hydraulic fracturing have attempted to connect the practice with seismic events, but the evidence is most inconclusive. The Energy Information Administration (EIA) has stated that if seismic events occur within the proximity of hydraulic fracturing activities, these events are rarely strong enough to be felt at the surface, let alone cause damage.
Energy Information Administration’s Introduction to shale gas production:
American Petroleum Institute’s website on environmental issues and the oil and gas industry: