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1Over the last decade, advances in technology have made it profitable to extract natural gas from shale, leading to a global boom in shale gas development. Newer technologies, such as hydraulic fracturing or “fracking” have enabled energy companies to access “unconventional” resources of gas, once considered too difficult or costly to extract, such as gas found deep underground, in tight impermeable rock formations, in coal beds, or trapped in layers of shale, fine-grained sedimentary rocks.

2France’s deposits of shale gas may be one of the largest in Western Europe, but fracking as well as the exploration of fracking potential are banned here. While 80 percent of the population is opposed to fracking, former President Nicolas Sarkozy recently came out in favor of exploring fracking’s potential to help boost employment and energy independence.

3Natural gas, a fossil fuel, was formed over millions of years as layers of decaying organisms were buried and exposed to intense heat and pressure under the earth. The energy of the sun that these plants and animals absorbed is embodied in the gas.

4Traditionally, natural gas was extracted by drilling into porous zones from which it could easily be pumped to the surface, but in the U.S., many of these resources have been tapped out. Some form of fracking is now used in 90 percent of all new onshore oil and gas development, and currently accounts for 60 percent of natural gas production in the U.S.

5Because of its potential environmental and health impacts, fracking has become a contentious issue in the U.S. According to a 2014 Pew poll (Pew, 2014), 41 percent of respondents support fracking while 47 percent are opposed; 12 percent are undecided.

6The United States’ experience with fracking can perhaps help France better assess the benefits and risks of fracking.

The Fracking Process

7Hydraulic fracking is not new. When the mining technique began in the 1940s, gas companies drilled vertical wells and pumped pressurized water into rocks to release the gas. Natural gas development exploded in the 1990s, however, when horizontal drilling was developed and combined with fracking; this enabled drills to descend down to 10,000 feet, then curve to drill horizontally thousands more feet so drillers could access gas trapped within shale layers. Horizontal drilling is 3 to 5 times more productive than vertical drilling.

8The process is multi-faceted. First a hole (or wellbore) is drilled 1,000 to 4,000 feet deep. After steel casings are placed into the well, the space between the casing and the hole is filled with cement to protect groundwater and prevent gas leaks. This process is repeated several times, with smaller and smaller diameter casings being inserted, down to a depth of 6,000 to 10,000 feet (far below aquifers), where the gas can be accessed. A perforated pipe gun is sent into the horizontal part of the wellbore, producing explosions that create fractures in the shale. Fracking fluid, 3 to 5 million gallons of water drawn from groundwater or surface water resources mixed with chemicals and sand, is then pumped at high pressure into fractures, which expand and release the gas.

9Ninety-eight to 99.5 percent of the fracking fluid is water and sand used to keep the cracks open; the rest is made up of chemicals that help reduce friction, kill microbes that might clog the well, prevent pipe corrosion, and acids to reduce drilling mud damage. Some are carcinogens and hazardous pollutants, but the exact chemicals used are usually unknown because the industry contends its fracking fluid formulas are trade secrets (Maule, 2013). The ingredients of any given fracking cocktail depend on the particular conditions at the well.

10Once pressure in the well is released, gas flows to the surface, as well as “produced” or “flowback” water (which can be from 3 to 80 percent of the water used) containing chemicals, salt and radioactive materials that occur naturally in shale. The flowback is stored on-site in tanks or pits before it is treated and released into surface waters, injected into deep wells for disposal, or recycled with or without treatment to be reused in more fracking.

11In the U.S., fracking fluids are not regulated by the federal Environmental Protection Agency (EPA) even when they enter our water supply because in 2005, fracking was given an exemption from the Safe Drinking Water Act; called the Halliburton Loophole, it was introduced when Vice President Cheney’s former employer, Halliburton, was moving into fracking.

12The U.S. natural gas industry is the world’s largest. According to the U.S. Energy Information Administration (EIA), in 2012, the nation had almost 323 trillion cubic feet of “proved” (able to be produced economically given current market prices) natural gas and natural gas liquid reserves (EIA, 2014). The EIA estimates that there are 2,203 trillion cubic feet of “technically recoverable” (able to be produced with current technology without regard to economics) natural gas. The U.S. consumes natural gas at a rate of about 24 trillion cubic feet per year, so 2,203 Tcf of gas could theoretically last 92 years.

13Today, there are about 45,000 shale gas wells operating in the U.S. and natural gas production is expected to increase 56 percent between 2012 and 2040 (EIA, 2014). The abundance of natural gas has made it a relatively cheap energy source.

The Benefits of Natural Gas

14Natural gas generates 27 percent of electricity in the U.S. [1], and approximately two-thirds of the natural gas produced in the U.S. goes into making chemicals, pharmaceuticals and fertilizer, and is used for heating and cooling.

15The boom in natural gas has helped make the U.S. much less dependent on countries like

16Russia and the Middle East for energy, and thus enhanced its energy security.

17A 2011 study by IHS (IHS, 2011), a global information provider, found that shale gas production in the U.S. supported over 600,000 jobs in 2010, and is projected to support 870,000 jobs by 2015 and 1.6 million by 2035. It boosts local economies with jobs, royalties for landowners and tax revenues. Mineral rights for fracking vary from state to state, but if a homeowner owns his mineral rights, he can earn substantial amounts for a signing bonus, then more in royalties if natural gas is discovered and continues flowing.

18IHS estimated that, over the next 25 years, shale gas production could generate more than$933 billion in tax revenues for local, state and the federal governments. Shale gas contributed over $76.9 billion to the U.S. gross domestic product in 2010; by 2015 it is expected to rise to $118.2 billion and $231.1 billion in 2035.

19Manufacturers of every day products and the steel industry also benefit from cheap natural gas and gain a competitive edge in global markets, resulting in more exports and jobs. The National Association of Manufacturers estimates that shale gasproduction and low natural gas prices will help manufacturers employ 1 million workers by 2025.

20Natural gas has been hailed as an energy source that can help slow climate change because it emits less carbon dioxide when burned than any other fossil fuel; since we are using more natural gas, we are producing fewer emissions from dirty coal.

The Problems with Natural Gas

21A new study (McJeon, 2014) of global energy use found that in the long run, inexpensive natural gas will not slow climate change because it will compete not only with coal, but also with cleaner nuclear and renewable energy technologies such as wind and solar. Indeed, new investments in renewables last year were the lowest since 2010 at $56 billion, while gas and oil investments were $168.2 billion, more than double the 2009 figure. Because it is cheap, natural gas could also expand overall energy use, thus undercutting progress made through implementing energy efficiency measures.

22Natural gas is mostly methane, a greenhouse gas that, over 20 years, traps more than 84 times more heat in the atmosphere than carbon dioxide. Approximately one-third of the global warming we are experiencing today is caused by short-term climate pollutants, including methane. In 2012, natural gas production was the second largest manmade source of methane emissions in the U.S. (EPA, 2014).

23During the fracking process, methane is released into the atmosphere when it escapes via pneumatic valves that control operations at the well site, other equipment at the production site, or when excess gas is vented. These problems can be remedied with low- or no-emission valves and better leak detection and repair. Green completion equipment can recover excess methane, process it and send it to a pipeline so that it can then be sold. In January 2015, the EPA will begin requiring green completions for all natural gas producers; until then they are permitted to flare the gas. A study by ICF International concluded that emissions-control technologies and practices could save natural gas companies over $164 million a year (ICF, 2014).

24Unless the methane emissions associated with natural gas production can be curbed, any climate benefits of natural gas could be undone. The problem is that no one has identified precisely how much or where in the process methane emissions are occurring. The Environmental Defense Fund (EDF) and approximately 100 partners are currently researching how much methane is released across the entire natural gas supply chain; the16-part study is due to be completed at the end of 2014.

25Natural gas development has also resulted in increased emissions of volatile organic compounds (VOCs) like benzene and formaldehyde, and hazardous air pollutants, which can have health consequences for those living nearby or working in the industry. VOCs can cause cancer and respiratory problems, particulate matter can affect the heart and lungs, nitrogen oxides react with VOCs to produce ozone, and hydrogen sulfide can cause illness or death at some concentrations. These air pollutants emanate from diesel- or natural gas-fueled trucks and equipment, gas production, and leaks from storage facilities, pipelines and valves.

26In Wise County, Texas, which sits atop a vast shale deposit called the Barnett Shale, Bob and Lisa Parr are surrounded by gas wells. After several years of experiencing nosebleeds, nausea, ringing ears and rashes, which they attribute to toxic emissions from gas production, the Parrs sued Aruba Petroleum and were recently awarded $2.925 million in damages. The case is significant because it is the first successful U.S. lawsuit linking toxic air emissions from oil or gas production to health impacts on nearby residents, but Aruba will challenge the ruling. The Parrs live near the town of Denton, Texas that in November voted to ban fracking, the first municipality in Texas to do so.

27In the U.S., the regulation of oil and gas extraction falls mainly to the states, including enforcement of the federal Clean Air Act, but rules vary widely from state to state. The first federal air pollution regulation on fracking is the EPA’s 2015 requirement for green completions, but many believe it’s not enough. In May 2014, 64 environmental and community groups petitioned the agency to use its authority under the Clean Air Act to develop «robust emission standards» limiting the amounts of benzene, formaldehyde and other harmful chemicals that can be emitted by oil and gas wells and equipment.

28There are many environmental risks related to the large amounts of water used in fracking. The huge volumes of water drawn for fracking can jeopardize the availability and quality of drinking water. Fracking fluids can contaminate surface and groundwater supplies if spilled or leaked. If wells are not constructed properly, fracking fluid might find its way through failures in the steel and cement casings to aquifers or groundwater carrying metals or radioactive materials naturally found underground. A recent study (Darrah, 2014) of 8 water wells contaminated by methane found that the methane had leaked through faulty cement, casings and underground well construction.

29Flowback waters can seep into surface or groundwater from trucking accidents or on-site storage leaks. And if wastewater is not properly treated before being released, it could contaminate surface water bodies. The EPA is currently studying fracking’s impacts on drinking water resources at every stage of the fracking cycle. A draft report due out this year could be the first step towards tough federal regulations of fracking.

30Because of the upsurge in fracking, more and more radioactive waste is coming to the surface more quickly from the shale, which naturally contains radioactive metals. Some radioactive metals may dissolve into the fracking fluid, contaminating it; some may remain in the dirt and rock being drilled that are eventually brought to the surface. Regulations about the disposal of fracking waste are different in each state, but often, radioactive waste ends up in landfills ill equipped to handle it, from where it can contaminate groundwater.

31Lately, there have been many reports that “fracking causes earthquakes.” Generally it is the pumping of wastewater deep into injection wells for disposal that can cause tremors. The number of earthquakes in central and eastern U.S. has increased significantly in recent years, coinciding with increased fracking and the injection of wastewater in disposal wells in Colorado, Oklahoma, Texas, Arkansas and Ohio, according to the Seismological Society of America. The society also recently revealed that earthquakes from wastewater disposal may be triggered tens of miles from the wellbore, much farther than previously thought.

32Geoff Abers, a seismologist research professor at Lamont-Doherty Earth Observatory a research unit of Columbia University in New York City, is studying the potential for earthquakes caused by the injection of wastewater, whether from fracking or other methods of extracting oil and gas that involve disposal of large amounts of fluid. Abers explained that wastewater is pumped deep into injection wells (some wells receive 1 million barrels each month), down into porous formations where it is soaked up; as pressure gradually builds, it sometimes triggers dormant faults. Some operations can run for 10 to 15 years without incident, whereas with others, quakes happen quickly. “We don’t understand why some injection wells have earthquakes and others don’t,” said Abers. “We know very little about where the fluid goes at depth, what the pressure is, or if there are any abandoned wells nearby.” Usually scientists only know when the larger earthquakes occur, but if monitoring were better, they would be able to detect signs of stresses building and faults getting close to failure.

33The fracking process itself, however, can also cause earthquakes. A study of 400 small earthquakes that occurred in 2013 in Ohio found that the actual fracking activity triggered the earthquakes, setting off the first known occurrence of seismicity in the area (Friberg,2014).

34Fracking operations also result in excessive light and noise from drilling operations, pumps and trucks. And because heavy truck traffic accompanies fracking, there are often more traffic accidents. Communities where fracking is taking place also experience more social disruption from the influx of mining workers.

Communities and Fracking

35Because they need the income that gas drilling can bring, low-income and minority communities will often accept fracking development (Apple, 2014). With fewer alternatives and resources for considering the pros and cons of fracking, low-income communities often agree to less compensation and regulation, which can leave them with environmental contamination, high rents and a drop in property values. Low-income residents may also have more health issues to begin with and limited access to health care, making them more vulnerable to pollution.

36North Carolina, which until early 2014 had a moratorium on fracking, is now considering the pros and cons of fracking, reviewing safety rules and is expected to legalize fracking in spring 2015. By examining U.S. census data from 2007 to 2011, researchers at the University of North Carolina Chapel Hill found that communities with more than 50 percent people of color were 4.2 times more likely to have leased their land for fracking than communities with less than 10 percent people of color. These communities had leased approximately 50 percent of their land for fracking (Werder, 2014).

37A new report by the Natural Resource Defense Council analyzed California state environmental health data to see which communities were most impacted by oil and gas drilling. It found that 14 percent of Californians currently live within one mile of the state’s 84,000 oil or gas wells. Over one-third of these people (1.8 million) live in communities that are already disproportionately burdened by pollution: 92 percent of them are people of color. These communities are comprised of 69 percent Hispanic, 11 percent Asian American, 10 percent African American and 2 percent other. If fracking development is expanded further, the environmental and health problems of these communities will likely be exacerbated (NRDC, 2014).

38More monitoring and more data made public are essential to understanding what the problems of the natural gas industry are, what its best practices should be and how the most vulnerable communities can be protected. Many strategies to safeguard the environment and public health have already been identified—getting them implemented in the U.S., though, is often a question of political will.

39In February 2014, Colorado became the first state to adopt rules to directly reduce emissions of methane and VOCs from oil and gas. The measures require: leak detection and repair on all wells to control methane and VOC leaks from equipment; monthly inspections for the largest emitting wells; a statewide retrofit using lower emission valves on all valves on well sites that control routine operations; and requiring existing storage tanks to comply with pollution laws. The new rules should remove 90,000 tons of VOCs and 100,000 tons of methane each year.

40Meanwhile, a patchwork of regulations is being developed as states come to grips with the local impacts of fracking. Illinois requires companies to reveal their fracking chemicals and test the water before and after drilling. Other states, like Wyoming, Arkansas, Pennsylvania, Michigan and Texas have enacted regulations requiring some some disclosure of fracking chemicals. Towns, cities and counties in states such as California, Colorado and Ohio, have established moratoria or bans on fracking. Vermont became the first state to ban fracking altogether in 2012; and in December 2014, fracking was banned in New York State because of health concerns.

41Around the U.S., communities are banding together to try to ban fracking in their towns and cities. But the global need for energy will continue to grow and hydraulic fracturing is not going away in the foreseeable future. What is needed is to better research, reduce and control the risks of fracking, while determinedly trying to move society to clean renewable energy.


Over the last decade, advances in technology have made it profitable to extract natural gas from shale, leading to a boom in shale gas development in the United States. Hydraulic fracturing, or fracking, the controversial method for extracting natural gas, offers numerous benefits : relatively cheap energy, enhanced energy security, job creation, tax revenues and decreased dependence on dirty coal. Fracking, however, can also increase greenhouse gas emissions, pollute the air and result in health effects, consume huge quantities of water, and cause earthquakes. While some areas welcome fracking for the economic benefits it brings, other communities are attempting to ban fracking altogether. This article examines the benefits and risks of fracking in the U.S


La fracturation hydraulique aux États-Unis

Ces dix dernières années, les progrès techniques ont transforme l’extraction du gaz naturel contenu dans les roches de schiste en une activité rentable, conduisant a un essor de l’exploitation de cette source d’énergie aux Etats-Unis. La fracturation hydraulique, technique controversée utilisée pour extraire le gaz naturel, offre de multiples avantages : elle permet d’accéder a une source d’énergie relativement bon marche, renforce la sécurité énergétique, favorise la création d’emplois, augmente les recettes fiscales et réduit la dépendance a l’égard du combustible polluant qu’est le charbon. Toutefois, elle peut aussi accroitre les émissions de gaz a effet de serre, aggraver la pollution atmosphérique et avoir des retombées négatives sur la santé, nécessiter l’utilisation d’énormes quantités d’eau et provoquer des séismes. Si la population de certaines régions est favorable a la fracturation en raison de ses retombées économiques positives, d’autres populations tentent de la faire interdire purement et simplement. Le présent article dresse un bilan des avantages et des risques de cette technique aux Etats-Unis.

Bibliographic References

  • Apple B.E. (2014), “Mapping Fracking: An Analysis of Law, Power, and Regional Distribution in the United States”, Harvard Environmental Law Review, vol. 38, issue 1, p. 217.
  • Darrah T.H., Vengosh A., Jackson R.B., Warner N.R., Poreda R.J. (2014), “Noble gases identify the mechanisms of fugitive gas contamination in drinking-water wells overlying the Marcellus and Barnett Shales”, Proceedings of the National Academy of Sciences of the United States of America, vol. 111, n° 39.
  • EIA, U.S. Energy Information Administration (2014a), “U.S. Crude Oil and Natural Gas Proved Reserves, 2012”, p. 1.
  • EIA, U.S. Energy Information Administration (2014b), “Annual Energy Outlook 2014 with projections to 2040”, p. MT-23.
  • EPA, U.S. Environmental Protection Agency (2014), “Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2012”, p. ES-14.
  • OnlineFriberg P.A., Besana-Ostman G.M., Dricker I. (2014), “Characterization of an Earthquake Sequence Triggered by Hydraulic Fracturing in Harrison County, Ohio”, Seismological Research Letters.
  • ICF International (2014), “Economic Analysis of Methane Emission Reduction Opportunities in the U.S. Onshore Oil and Natural Gas Industries”, p. 4-3.
  • IHS Global Insight (2011), “The Economic and Employment Contributions of Shale Gas in the United States”, p. v.
  • Maule A.L., Makey C.M., Benson E.B., Burrows A.B., Scammell M.K. (2013), “Disclosure of Hydraulic Fracturing Fluid Chemical Additives: Analysis of Regulations”, New Solutions: A Journal of Environmental and Occupational Health Policy, vol. 23, n° 1 / 2013, p. 169.
  • OnlineMcJeon H., Edmonds J., Bauer N., Clarke L., Fisher B., Flannery B.P., Hilaire J., Krey V., Marangoni G., Mi R., Riahi K., Rogner H., Tavoni M. (2014), “Limited impact on decadal-scale climate change from increased use of natural gas”, Nature.
  • NRDC, Natural Resources Defense Council (2014), “Drilling in California: Who’s at Risk?”, p. 4.
  • Pew Research Center for the People & the Press (2014), “Little Enthusiasm, Familiar Divisions After the GOP’s Big Midterm Victory” (
  • Werder E. (2014), “Race, Poverty and Hydraulic Fracturing in North Carolina”, North Carolina Environmental Justice Network 2014 EJ Summit Working Paper.
Renee Cho
Renee Cho is a staff blogger for the Earth Institute at Columbia University in New York City and a freelance environmental writer. Previously, she was Communications Coordinator for Riverkeeper, the Hudson River environmental organization.
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Uploaded on on 25/07/2015
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