-John from Lincoln Park-
Hydraulic fracturing, otherwise known as "fracking", uses small, controlled explosions and pressurized fluid to extract natural gas from within shale deposits. As the chart below shows, around 2008, the price of natural gas dropped significantly due largely to the abrupt drop in demand caused by the economic collapse of that year. At the same time, the exploitation of new natural gas finds in the major shale deposits in the Pennsylvania/New York/Ohio region and the development of existing deposits in the Texas/Arkansas region caused increased production within the US (the bar chart at the bottom of the image). This increased domestic supply combined with lower demand shifted the economics of natural gas, and pricing has remained low since that time.
Environmentally speaking, this offers a bit of a conundrum for those in the field of environmental protection. When burned, natural gas offers much less environmental damage from carbon dioxide, particulate matter, and sulfur/nitrogen oxides than coal or petroleum. Because of this, a shift to more natural gas could, theoretically, delay some of the major environmental impacts from climate change, could reduce air quality issues, and could create a much better economic situation from which to drive further improvements. On the other hand, the process of hydraulic fracturing has many issues that cause problems for the residents near the sites of the natural gas deposits, and larger impacts that may lessen the environmental benefit.
The process of fracking requires drilling straight down several thousand feet to find a shale deposit, then turning horizontally into the shale for several miles. The driller then sends down devices with explosive charges in them to create fractures in the rock formation into which a machine pumps water and chemical fluid to extract both the trapped pockets of natural gas within the formation as well as the natural gas that has chemically bonded to the rock. The charge device then runs back up the well, creating a vacuum that draws the natural gas out of the formation. Because of the horizontal drilling capabilities, a single vertical well can mine several square miles of deposit. When completing the process, the driller is required to pump the wastewater back into the injection well as a means of disposal.
The primary environmental concerns come from four major aspects of the drilling: 1. polluting of underground water system with the chemical solutions used, 2. increased seismic activity due to the wastewater disposal, 3. the destruction of rural landscape with permanent damage due to drilling and infrastructure creation, and 4. the release of methane during the drilling process.
Water pollution
Companies that drill for natural gas by fracking consider the chemical solutions they use a proprietary technology that they should not have to make public. Environmental groups charge that without transparency and oversight, no one can know whether the process releases chemical compounds into the groundwater. Texas has started to required disclosure, and others will follow. If done properly, drilling as part of fracking should include a thick concrete silo at the top of the well running well below the water table (that sits only within the first several hundred feet below the surface). This should, in theory, prevent the pollution of underground water sources, however recent events in Pennsylvania have raised doubts about industry practices and have increased calls for more regulation. It remains to be seen if regulating the quality of well encasements will eliminate the issues, or if they are intrinsic to the process.
Seismic activity
Although some have concerns over the underground explosions that fracture the rock, the pressurization of waste fluids back into the well actually cause the seismic activity associated with hydraulic fracturing. Scientists on both sides agree that all forms of drilling cause increases in activity due to this wastewater disposal. However, disagreement comes from the seriousness of the issue. One study notes that magnitude 3 seismic activity has increased sharply in the Midwest due to fracking operations. Others note that disposal has happened at tens of thousands of sites for over twenty years, so we would have noticed problems well before this. As fracking moves drilling operations closer and closer to urban areas than previous forms of fossil fuel exploration, we will see which side is right.
Destruction of land
Like development of wind farms, fracking development requires the taking of land (largely forest clearing or farmland) to create the well and gravel roads and infrastructure to support the extraction. In addition, prior to pumping the waste fluids back into the well, companies store the fluid in surface ponds near the well site. All of these conditions create land that cannot easily be restored to its previous use (and in the case of the well head, never). To date, I have not heard of a requirement that companies put up the capital to restore areas to their previous use as part of their development.
Methane release
Methane has a higher potency as a greenhouse gas than carbon dioxide. Although natural gas (largely composed of methane) when burned releases less carbon dioxide, when extracting it, leakage from well heads can reduce or eliminate the benefit.
Fracking has made energy costs cheaper in this country. This will invariably lead to an increase in the use of natural gas as a competitor to other fossil fuels, which will increase demand and prices accordingly. Right now, we enjoy the lower cost of heating and producing electricity, but this comes at a cost. In the European Union, they practice the precautionary principle to have some assurance that practices will be benign before they gain widespread use. In our case, we do not practice that principle, and therefore must wait until something is in widespread use before we learn whether it is dangerous to us. The early results suggest that human quality of life in the areas of development has been threatened. With the benefit of reduced greenhouse gas emissions being called into question, the remaining benefit is the reduced cost of energy. In the short term, it definitely helps. But in the long term, would the investments in exploration have been better spent on efficiency, thereby reducing costs in the short and long term? Only time will tell.
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