Hydraulic Fracturing

Also known as "fracking", hydraulic fracturing is used to tap into extremely deep fossil fuel reserves located 7000 feet or more below the earth’s surface. Millions of liters of water and sand, combined with chemical substances, are used to send shocks through the rock layers and crack it open to release the trapped fossil fuels.

Opposition to hydraulic fracturing

Environmentalists have opposed hydraulic fracturing based on a number of points including its apparent links to methane leaks, flammable drinking water, contamination of soils, air and water as well as its possible link to earthquakes. In 2010 a documentary called "Gasland" attracted global attention from the general public by showing residents living next to fracking wells being able to set their tap water and rivers on fire, while their properties were covered with dead animals. However, the film was heavily criticised by organisations like the Independent Petroleum Association of America and industry specialists like Dr. Michael Economides, a professor of engineering at the University of Houston, for containing factual inaccuracies.

Methane leakages

Opponents of fracking argue that it stands in contradiction with meeting targets on climate change. This is because although the combustion of natural gas produces 30 percent less carbon dioxide than oil and 45 percent less than coal, the practice can release considerable amounts of methane.. Methane is a greenhouse gas 23 times more potent than carbon dioxide. A study conducted by a group of scientists from the Cooperative Institute for Research in Environmental Sciences (CIRES) and the National Oceanic and Atmospheric Administration (NOAA) showed that natural gas fields in the Uintah Basin (Western United States) leaked 6 to 12 percent of the methane produced.

Waste of vast amounts of water

Opponents also cite the vast amounts of water used as a disadvantage of fracking. A post on the ThinkProgress blog, an outlet of the public policy research and advocacy organization Center for American Progress, states that only 20 to 25 percent of the water used in fracking is recovered. The water usage of the technique is also likely to put a strain on areas with a drier climate such as the US Southern States (e.g. Texas and New Mexico). In Dimmit County, Texas, hydraulic fracturing uses one quarter of the county's water consumption. In contrast, in the wetter Marcellus shale region of Pennsylvania, Ohio, and New York, the water needs for an entire fracturing operation represent only 17 days of the average local rainfall.

Contamination of soils, air and water

The contamination of water with methane and other chemicals in areas where drilling takes place has also been linked to hydraulic fracturing. Research published by a team under Robert Jackson, from Duke University, found that in a sample of 141 private drinking-water wells in an area of about 5000 drilling sites in the Marcellus Shale (a gas-rich geological formation in northeastern Pennsylvania), four out of five wells contained methane. According to the study, concentrations of the gas were also six times higher in these wells than in those further away. Levels of ethane and propane, other ingredients of natural gas, were higher, too. Generally, the concentrations of all these components were above the levels considered safe by the Department of Interior.

Similarly a study by the University of Texas at Arlington found high levels of arsenic and other heavy metals in groundwater near natural gas fracturing sites in Texas' Barnett Shale. The study states that "analyses revealed that arsenic, selenium, strontium and total dissolved solids (TDS) exceeded the Environmental Protection Agency’s Drinking Water Maximum Contaminant Limit (MCL) in some samples from private water wells located within 3 km of active natural gas wells."

Cause of earthquakes

In 2011, the Oklahoma Geological Survey linked about 50 earthquakes in Oklahoma to fracking, stating: "Our analysis showed that shortly after hydraulic fracturing began small earthquakes started occurring, and more than 50 were identified, of which 43 were large enough to be located. Most of these earthquakes occurred within a 24 hour period after hydraulic fracturing operations had ceased."

Support for hydraulic fracturing

Supporters of fracking state that if done the right way, the technique is safe and clean. A report by the Massachusetts Institute of Technology concluded that only a small number of more than 20,000 wells drilled for fracturing in the previous decade had led to groundwater contamination and that all of these incidents resulted from breaches of existing regulations. The study also states that "there has been no evidence that fractures can penetrate shallow freshwater zones and contaminate them with fracturing fluid".

In a critique of the film Gasland, Dr. Micheal Economides, a professor of engineering at the University of Houston, states that the contamination of drinking water with methane as a result of fracturing is very unlikely because "the vertical depth separation between drinking water aquifers and reservoir targets for gas production is several thousand feet of impermeable rock. Any interchange between the two, if it were possible, would have happened already in geological time, measured in tens of millions of years, not in recent history."

Confusion over terminology

An article in the New York Times claimed that confusion over the use and definition of the term hydraulic facturing lies at the center of the debate between the technique's supporters and opponents. According to the article, supporters of the technique use the term hydraulic fracturing or "fracking" to describe just one part of the process, the injection of chemical-laced water and sand to break apart rock and release gas, while opponents refer to the term as including the drilling phase. In this way, both parties can use the terminology to their advantage and can talk past one another as a result. Robert Jackson, professor at Duke University and author of a study about the methane contamination of ground water near fracturing sites, argues that the main problem is not the "fracking" but the drilling.