Environmental impact of hydraulic fracturing

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

The environmental impact of hydraulic fracturing is related to land use and water consumption, air emissions, including methane emissions, brine and fracturing fluid leakage, water contamination, noise pollution, and health. Water and air pollution are the biggest risks to human health from hydraulic fracturing.[1] Research has determined that hydraulic fracturing negatively affects human health and drives climate change.[2][3][4]

Hydraulic fracturing fluids include proppants and other substances, which include chemicals known to be toxic, as well as unknown chemicals that may be toxic.[5] In the United States, such additives may be treated as trade secrets by companies who use them. Lack of knowledge about specific chemicals has complicated efforts to develop risk management policies and to study health effects.[6][7] In other jurisdictions, such as the United Kingdom, these chemicals must be made public and their applications are required to be nonhazardous.[8]

Water usage by hydraulic fracturing can be a problem in areas that experience water shortage. Surface water may be contaminated through spillage and improperly built and maintained waste pits, in jurisdictions where these are permitted.[9] Further, ground water can be contaminated if fracturing fluids and formation fluids are able to escape during hydraulic fracturing. However, the possibility of groundwater contamination from the fracturing fluid upward migration is negligible, even in a long-term period.[10][11] Produced water, the water that returns to the surface after hydraulic fracturing, is managed by underground injection, municipal and commercial wastewater treatment, and reuse in future wells.[12] There is potential for methane to leak into ground water and the air, though escape of methane is a bigger problem in older wells than in those built under more recent legislation.[13]

Hydraulic fracturing causes induced seismicity called microseismic events or microearthquakes. The magnitude of these events is too small to be detected at the surface, being of magnitude M-3 to M-1 usually. However, fluid disposal wells (which are often used in the USA to dispose of polluted waste from several industries) have been responsible for earthquakes up to 5.6M in Oklahoma and other states.[14]

Governments worldwide are developing regulatory frameworks to assess and manage environmental and associated health risks, working under pressure from industry on the one hand, and from anti-fracking groups on the other.[15][16]: 3–7 In some countries like France a precautionary approach has been favored and hydraulic fracturing has been banned.[17][18] The United Kingdom's regulatory framework is based on the conclusion that the risks associated with hydraulic fracturing are manageable if carried out under effective regulation and if operational best practices are implemented.[15] It has been suggested by the authors of meta-studies that in order to avoid further negative impacts, greater adherence to regulation and safety procedures are necessary.[19][20][21]

Air emissions[edit]

A report for the European Union on the potential risks was produced in 2012. Potential risks are "methane emissions from the wells, diesel fumes and other hazardous pollutants, ozone precursors or odours from hydraulic fracturing equipment, such as compressors, pumps, and valves". Also gases and hydraulic fracturing fluids dissolved in flowback water pose air emissions risks.[13] One study measured various air pollutants weekly for a year surrounding the development of a newly fractured gas well and detected nonmethane hydrocarbons, methylene chloride (a toxic solvent), and polycyclic aromatic hydrocarbons. These pollutants have been shown to affect fetal outcomes.[22]

The relationship between hydraulic fracturing and air quality can influence acute and chronic respiratory illnesses, including exacerbation of asthma (induced by airborne particulates, ozone and exhaust from equipment used for drilling and transport) and COPD. For example, communities overlying the Marcellus shale have higher frequencies of asthma. Children, active young adults who spend time outdoors, and the elderly are particularly vulnerable. OSHA has also raised concerns about the long-term respiratory effects of occupational exposure to airborne silica at hydraulic fracturing sites. Silicosis can be associated with systemic autoimmune processes.[23]

"In the UK, all oil and gas operators must minimise the release of gases as a condition of their licence from the Department of Energy and Climate Change (DECC). Natural gas may only be vented for safety reasons."[24]

Also transportation of necessary water volume for hydraulic fracturing, if done by trucks, can cause emissions.[25] Piped water supplies can reduce the number of truck movements necessary.[26]

A report from the Pennsylvania Dept of Environmental Protection indicated that there is little potential for radiation exposure from oil and gas operations.[27]

Air pollution is of particular concern to workers at hydraulic fracturing well sites as the chemical emissions from storage tanks and open flowback pits combine with the geographically compounded air concentrations from surrounding wells.[23] Thirty seven percent of the chemicals used in hydraulic fracturing operations are volatile and can become airborne.[23]

Researchers Chen and Carter from the Department of Civil and Environmental Engineering, University of Tennessee, Knoxville used atmospheric dispersion models (AERMOD) to estimate the potential exposure concentration of emissions for calculated radial distances of 5 m to 180m from emission sources.[28] The team examined emissions from 60,644 hydraulic fracturing wells and found “results showed the percentage of wells and their potential acute non-cancer, chronic non-cancer, acute cancer, and chronic cancer risks for exposure to workers were 12.41%, 0.11%, 7.53%, and 5.80%, respectively. Acute and chronic cancer risks were dominated by emissions from the chemical storage tanks within a 20 m radius.[28]

Climate change[edit]

Hydraulic fracturing is a driver of climate change.[4][29] However, whether natural gas produced by hydraulic fracturing causes higher well-to-burner emissions than gas produced from conventional wells is a matter of contention. Some studies have found that hydraulic fracturing has higher emissions due to methane released during completing wells as some gas returns to the surface, together with the fracturing fluids. Depending on their treatment, the well-to-burner emissions are 3.5%–12% higher than for conventional gas.[30]

A debate has arisen particularly around a study by professor Robert W. Howarth finding shale gas significantly worse for global warming than oil or coal.[31] Other researchers have criticized Howarth's analysis,[32][33] including Cathles et al., whose estimates were substantially lower."[34] A 2012 industry funded report co-authored by researchers at the United States Department of Energy's National Renewable Energy Laboratory found emissions from shale gas, when burned for electricity, were "very similar" to those from so-called "conventional well" natural gas, and less than half the emissions of coal.[12]

Several studies which have estimated lifecycle methane leakage from natural gas development and production have found a wide range of leakage rates.[35][36][37] According to the Environmental Protection Agency's Greenhouse Gas Inventory, the methane leakage rate is about 1.4%.[38] A 16-part assessment of methane leakage from natural gas production initiated by the Environmental Defense Fund[39] found that fugitive emissions in key stages of the natural gas production process are significantly higher than estimates in the EPA's national emission inventory, with a leakage rate of 2.3 percent of overall natural gas output.[35]

Water consumption[edit]

Massive hydraulic fracturing typical of shale wells uses between 1.2 and 3.5 million US gallons (4,500 and 13,200 m3) of water per well, with large projects using up to 5 million US gallons (19,000 m3). Additional water is used when wells are refractured.[40][41] An average well requires 3 to 8 million US gallons (11,000 to 30,000 m3) of water over its lifetime.[41][42][43][44] According to the Oxford Institute for Energy Studies, greater volumes of fracturing fluids are required in Europe, where the shale depths average 1.5 times greater than in the U.S.[45] Whilst the published amounts may seem large, they are small in comparison with the overall water usage in most areas. A study in Texas, which is a water shortage area, indicates "Water use for shale gas is <1% of statewide water withdrawals; however, local impacts vary with water availability and competing demands."[46]

A report by the Royal Society and the Royal Academy of Engineering shows the usage expected for hydraulic fracturing a well is approximately the amount needed to run a 1,000 MW coal-fired power plant for 12 hours.[15] A 2011 report from the Tyndall Centre estimates that to support a 9 billion cubic metres per annum (320×10^9 cu ft/a) gas production industry, between 1.25 to 1.65 million cubic metres (44×10^6 to 58×10^6 cu ft) would be needed annually,[47] which amounts to 0.01% of the total water abstraction nationally.

Concern has been raised over the increasing quantities of water for hydraulic fracturing in areas that experience water stress. Use of water for hydraulic fracturing can divert water from stream flow, water supplies for municipalities and industries such as power generation, as well as recreation and aquatic life.[48] The large volumes of water required for most common hydraulic fracturing methods have raised concerns for arid regions, such as the Karoo in South Africa,[49] and in drought-prone Texas, in North America.[50] It may also require water overland piping from distant sources.[43]

A 2014 life cycle analysis of natural gas electricity by the National Renewable Energy Laboratory concluded that electricity generated by natural gas from massive hydraulically fractured wells consumed between 249 gallons per megawatt-hour (gal/MWhr) (Marcellus trend) and 272 gal/MWhr (Barnett Shale). The water consumption for the gas from massive hydraulic fractured wells was from 52 to 75 gal/MWhr greater (26 percent to 38 percent greater) than the 197 gal/MWhr consumed for electricity from conventional onshore natural gas.[51]

Some producers have developed hydraulic fracturing techniques that could reduce the need for water.[52] Using carbon dioxide, liquid propane or other gases instead of water have been proposed to reduce water consumption.[53] After it is used, the propane returns to its gaseous state and can be collected and reused. In addition to water savings, gas fracturing reportedly produces less damage to rock formations that can impede production.[52] Recycled flowback water can be reused in hydraulic fracturing.[30] It lowers the total amount of water used and reduces the need to dispose of wastewater after use. The technique is relatively expensive, however, since the water must be treated before each reuse and it can shorten the life of some types of equipment.[54]

Water contamination[edit]

Injected fluid[edit]

In the United States, hydraulic fracturing fluids include proppants, radionuclide tracers, and other chemicals, many of which are toxic.[5] The type of chemicals used in hydraulic fracturing and their properties vary. While most of them are common and generally harmless, some chemicals are carcinogenic.[5] Out of 2,500 products used as hydraulic fracturing additives in the United States, 652 contained one or more of 29 chemical compounds which are either known or possible human carcinogens, regulated under the Safe Drinking Water Act for their risks to human health, or listed as hazardous air pollutants under the Clean Air Act.[5] Another 2011 study identified 632 chemicals used in United States natural gas operations, of which only 353 are well-described in the scientific literature.[23] A study that assessed health effects of chemicals used in fracturing found that 73% of the products had between 6 and 14 different adverse health effects including skin, eye, and sensory organ damage; respiratory distress including asthma; gastrointestinal and liver disease; brain and nervous system harms; cancers; and negative reproductive effects.[55]

An expansive study conducted by the Yale School of Public Health in 2016 found numerous chemicals involved in or released by hydraulic fracturing are carcinogenic.[56] Of the 119 compounds identified in this study with sufficient data, “44% of the water pollutants...were either confirmed or possible carcinogens.” However, the majority of chemicals lacked sufficient data on carcinogenic potential, highlighting the knowledge gap in this area. Further research is needed to identify both carcinogenic potential of chemicals used in hydraulic fracturing and their cancer risk.[56]

The European Union regulatory regime requires full disclosure of all additives.[6] According to the EU groundwater directive of 2006, "in order to protect the environment as a whole, and human health in particular, detrimental concentrations of harmful pollutants in groundwater must be avoided, prevented or reduced."[57] In the United Kingdom, only chemicals that are "non hazardous in their application" are licensed by the Environment Agency.[8]


Less than half of injected water is recovered as flowback or later production brine, and in many cases recovery is <30%.[58] As the fracturing fluid flows back through the well, it consists of spent fluids and may contain dissolved constituents such as minerals and brine waters.[59] In some cases, depending on the geology of the formation, it may contain uranium, radium, radon and thorium.[60] Estimates of the amount of injected fluid returning to the surface range from 15-20% to 30–70%.[58][59][61]

Approaches to managing these fluids, commonly known as produced water, include underground injection, municipal and commercial wastewater treatment and discharge, self-contained systems at well sites or fields, and recycling to fracture future wells.[12][59][62][63] The vacuum multi-effect membrane distillation system as a more effective treatment system has been proposed for treatment of flowback.[64] However, the quantity of waste water needing treatment and the improper configuration of sewage plants have become an issue in some regions of the United States. Part of the wastewater from hydraulic fracturing operations is processed there by public sewage treatment plants, which are not equipped to remove radioactive material and are not required to test for it.[65][66]

Produced water spills and subsequent contamination of groundwater also presents a risk for exposure to carcinogens. Research that modeled the solute transport of BTEX (benzene, toluene, ethylbenzene, and xylene) and naphthalene for a range of spill sizes on contrasting soils overlying groundwater at different depths found that benzene and toluene were expected to reach human health relevant concentration in groundwater because of their high concentrations in produced water, relatively low solid/liquid partition coefficient and low EPA drinking water limits for these contaminants.[67] Benzene is a known carcinogen which affects the central nervous system in the short term and can affect the bone marrow, blood production, immune system, and urogenital systems with long term exposure.[citation needed]

Surface spills[edit]

Surface spills related to the hydraulic fracturing occur mainly because of equipment failure or engineering misjudgments.[9]

Volatile chemicals held in waste water evaporation ponds can evaporate into the atmosphere, or overflow. The runoff can also end up in groundwater systems. Groundwater may become contaminated by trucks carrying hydraulic fracturing chemicals and wastewater if they are involved in accidents on the way to hydraulic fracturing sites or disposal destinations.[68]

In the evolving European Union legislation, it is required that "Member States should ensure that the installation is constructed in a way that prevents possible surface leaks and spills to soil, water or air."[69] Evaporation and open ponds are not permitted. Regulations call for all pollution pathways to be identified and mitigated. The use of chemical proof drilling pads to contain chemical spills is required. In the UK, total gas security is required, and venting of methane is only permitted in an emergency.[70][71][72]


In September 2014, a study from the US 'Proceedings of the National Academy of Sciences' released a report that indicated that methane contamination can be correlated to distance from a well in wells that were known to leak. This however was not caused by the hydraulic fracturing process, but by poor cementation of casings.[73][74]

Groundwater methane contamination has adverse effect on water quality and in extreme cases may lead to potential explosion.[75] A scientific study conducted by researchers of Duke University found high correlations of gas well drilling activities, including hydraulic fracturing, and methane pollution of the drinking water.[75] According to the 2011 study of the MIT Energy Initiative, "there is evidence of natural gas (methane) migration into freshwater zones in some areas, most likely as a result of substandard well completion practices i.e. poor quality cementing job or bad casing, by a few operators."[76] A 2013 Duke study suggested that either faulty construction (defective cement seals in the upper part of wells, and faulty steel linings within deeper layers) combined with a peculiarity of local geology may be allowing methane to seep into waters; the latter cause may also release injected fluids to the aquifer.[77] Abandoned gas and oil wells also provide conduits to the surface in areas like Pennsylvania, where these are common.[78]

A study by Cabot Oil and Gas examined the Duke study using a larger sample size, found that methane concentrations were related to topography, with the highest readings found in low-lying areas, rather than related to distance from gas production areas. Using a more precise isotopic analysis, they showed that the methane found in the water wells came from both the formations where hydraulic fracturing occurred, and from the shallower formations.[79] The Colorado Oil & Gas Conservation Commission investigates complaints from water well owners, and has found some wells to contain biogenic methane unrelated to oil and gas wells, but others that have thermogenic methane due to oil and gas wells with leaking well casing.[80] A review published in February 2012 found no direct evidence that hydraulic fracturing actual injection phase resulted in contamination of ground water, and suggests that reported problems occur due to leaks in its fluid or waste storage apparatus; the review says that methane in water wells in some areas probably comes from natural resources.[81][82]

Another 2013 review found that hydraulic fracturing technologies are not free from risk of contaminating groundwater, and described the controversy over whether the methane that has been detected in private groundwater wells near hydraulic fracturing sites has been caused by drilling or by natural processes.[83]


There are naturally occurring radioactive materials (NORM), for example radium, radon,[84] uranium, and thorium,[60][85][86] in shale deposits.[66] Brine co-produced and brought to the surface along with the oil and gas sometimes contains naturally occurring radioactive materials; brine from many shale gas wells, contains these radioactive materials.[66][87][88] The U.S. Environmental Protection Agency and regulators in North Dakota consider radioactive material in flowback a potential hazard to workers at hydraulic fracturing drilling and waste disposal sites and those living or working nearby if the correct procedures are not followed.[89][90] A report from the Pennsylvania Department of Environmental Protection indicated that there is little potential for radiation exposure from oil and gas operations.[27]

Land usage[edit]

In the UK, the likely well spacing visualised by the December 2013 DECC Strategic Environmental Assessment report indicated that well pad spacings of 5 km were likely in crowded areas, with up to 3 hectares (7.4 acres) per well pad. Each pad could have 24 separate wells. This amounts to 0.16% of land area.[91] A study published in 2015 on the Fayetteville Shale found that a mature gas field impacted about 2% of the land area and substantially increased edge habitat creation. Average land impact per well was 3 hectares (about 7 acres) [92] Research indicates that effects on ecosystem services costs (i.e. those processes that the natural world provides to humanity) has reached over $250 million per year in the U.S.[93]


Hydraulic fracturing causes induced seismicity called microseismic events or microearthquakes. These microseismic events are often used to map the horizontal and vertical extent of the fracturing.[94] The magnitude of these events is usually too small to be detected at the surface, although the biggest micro-earthquakes may have the magnitude of about -1.5 (Mw).[95]

Induced seismicity from hydraulic fracturing[edit]

As of August 2016, there were at least nine known cases of fault reactivation by hydraulic fracturing that caused induced seismicity strong enough to be felt by humans at the surface: In Canada, there have been three in Alberta (M 4.8[96] and M 4.4[97] and M 4.4[98]) and three in British Columbia (M 4.6,[99] M 4.4[100] and M 3.8[101]); In the United States there has been: one in Oklahoma (M 2.8[102]) and one in Ohio (M 3.0),[103] and; In the United Kingdom, there have been two in Lancashire (M 2.3 and M 1.5).[104]

Induced seismicity from water disposal wells[edit]

According to the USGS only a small fraction of roughly 30,000 waste fluid disposal wells for oil and gas operations in the United States have induced earthquakes that are large enough to be of concern to the public.[14] Although the magnitudes of these quakes has been small, the USGS says that there is no guarantee that larger quakes will not occur.[105] In addition, the frequency of the quakes has been increasing. In 2009, there were 50 earthquakes greater than magnitude 3.0 in the area spanning Alabama and Montana, and there were 87 quakes in 2010. In 2011 there were 134 earthquakes in the same area, a sixfold increase over 20th century levels.[106] There are also concerns that quakes may damage underground gas, oil, and water lines and wells that were not designed to withstand earthquakes.[105][107]

A 2012 US Geological Survey study reported that a "remarkable" increase in the rate of M ≥ 3 earthquakes in the US midcontinent "is currently in progress", having started in 2001 and culminating in a 6-fold increase over 20th century levels in 2011. The overall increase was tied to earthquake increases in a few specific areas: the Raton Basin of southern Colorado (site of coalbed methane activity), and gas-producing areas in central and southern Oklahoma, and central Arkansas.[108] While analysis suggested that the increase is "almost certainly man-made", the USGS noted: "USGS's studies suggest that the actual hydraulic fracturing process is only very rarely the direct cause of felt earthquakes." The increased earthquakes were said to be most likely caused by increased injection of gas-well wastewater into disposal wells.[14] The injection of waste water from oil and gas operations, including from hydraulic fracturing, into saltwater disposal wells may cause bigger low-magnitude tremors, being registered up to 3.3 (Mw).[95]


Each well pad (in average 10 wells per pad) needs during preparatory and hydraulic fracturing process about 800 to 2,500 days of activity, which may affect residents. In addition, noise is created by transport related to the hydraulic fracturing activities.[13] Noise pollution from hydraulic fracturing operations (e.g., traffic, flares/burn-offs) is often cited as a source of psychological distress, as well as poor academic performance in children.[109] For example, the low-frequency noise that comes from well pumps contributes to irritation, unease, and fatigue.[110]

The UK Onshore Oil and Gas (UKOOG) is the industry representative body, and it has published a charter that shows how noise concerns will be mitigated, using sound insulation, and heavily silenced rigs where this is needed.[111]

Safety issues[edit]

In July 2013, the United States Federal Railroad Administration listed oil contamination by hydraulic fracturing chemicals as "a possible cause" of corrosion in oil tank cars.[112]

Community impacts[edit]

Impacted communities are often already vulnerable, including poor, rural, or indigenous persons, who may continue to experience the deleterious effects of hydraulic fracturing for generations. Competition for resources between farmers and oil companies contributes to stress for agricultural workers and their families, as well as to a community-level “us versus them” mentality that creates community distress (Morgan et al. 2016). Rural communities that host hydraulic fracturing operations often experience a “boom/bust cycle,” whereby their population surges, consequently exerting stress on community infrastructure and service provision capabilities (e.g., medical care, law enforcement).

Indigenous and agricultural communities may be particularly impacted by hydraulic fracturing, given their historical attachment to, and dependency on, the land they live on, which is often damaged as a result of the hydraulic fracturing process.[113] Native Americans, particularly those living on rural reservations, may be particularly vulnerable to the effects of fracturing; that is, on the one hand, tribes may be tempted to engage with the oil companies to secure a source of income but, on the other hand, must often engage in legal battles to protect their sovereign rights and the natural resources of their land.[114]

Policy and science[edit]

There are two main approaches to regulation that derive from policy debates about how to manage risk and a corresponding debate about how to assess risk.[16]: 3–7

The two main schools of regulation are science-based assessment of risk and the taking of measures to prevent harm from those risks through an approach like hazard analysis, and the precautionary principle, where action is taken before risks are well-identified.[115] The relevance and reliability of risk assessments in communities where hydraulic fracturing occurs has also been debated amongst environmental groups, health scientists, and industry leaders. The risks, to some, are overplayed and the current research is insufficient in showing the link between hydraulic fracturing and adverse health effects, while to others the risks are obvious and risk assessment is underfunded.[116]

Different regulatory approaches have thus emerged. In France and Vermont for instance, a precautionary approach has been favored and hydraulic fracturing has been banned based on two principles: the precautionary principle and the prevention principle.[17][18] Nevertheless, some States such as the U.S. have adopted a risk assessment approach, which had led to many regulatory debates over the issue of hydraulic fracturing and its risks.

In the UK, the regulatory framework is largely being shaped by a report commissioned by the UK Government in 2012, whose purpose was to identify the problems around hydraulic fracturing and to advise the country's regulatory agencies. Jointly published by the Royal Society and the Royal Academy of Engineering, under the chairmanship of Professor Robert Mair, the report features ten recommendations covering issues such as groundwater contamination, well integrity, seismic risk, gas leakages, water management, environmental risks, best practice for risk management, and also includes advice for regulators and research councils.[15][117] The report was notable for stating that the risks associated with hydraulic fracturing are manageable if carried out under effective regulation and if operational best practices are implemented.

A 2013 review concluded that, in the US, confidentiality requirements dictated by legal investigations have impeded peer-reviewed research into environmental impacts.[83]

There are numerous scientific limitations to the study of the environmental impact of hydraulic fracturing. The main limitation is the difficulty in developing effective monitoring procedures and protocols, for which there are several main reasons:

  • Variability among fracturing sites in terms of ecosystems, operation sizes, pad densities, and quality-control measures makes it difficult to develop a standard protocol for monitoring.[118]
  • As more fracturing sites develop, the chance for interaction between sites increases, greatly compounding the effects and making monitoring of one site difficult to control. These cumulative effects can be difficult to measure, as many of the impacts develop very slowly.[119]
  • Due to the vast number of chemicals involved in hydraulic fracturing, developing baseline data is challenging. In addition, there is a lack of research on the interaction of the chemicals used in hydraulic fracturing fluid and the fate of the individual components.[120]

See also[edit]


  1. ^ Urbina, Ian (15 May 2012). "Drilling Down". The New York Times. Retrieved 4 August 2020.
  2. ^ Bamber, AM; Hasanali, SH; Nair, AS; Watkins, SM; Vigil, DI; Van Dyke, M; McMullin, TS; Richardson, K (15 June 2019). "A Systematic Review of the Epidemiologic Literature Assessing Health Outcomes in Populations Living near Oil and Natural Gas Operations: Study Quality and Future Recommendations". International Journal of Environmental Research and Public Health. 16 (12): 2123. doi:10.3390/ijerph16122123. PMC 6616936. PMID 31208070.
  3. ^ Wright, R; Muma, RD (May 2018). "High-Volume Hydraulic Fracturing and Human Health Outcomes: A Scoping Review". Journal of Occupational and Environmental Medicine. 60 (5): 424–429. doi:10.1097/JOM.0000000000001278. PMID 29370009. S2CID 13653132.
  4. ^ a b Tabuchi, Hiroko (2 June 2021). "Here Are America's Top Methane Emitters. Some Will Surprise You". The New York Times. ISSN 0362-4331. Retrieved 7 June 2021.
  5. ^ a b c d Chemicals Used in Hydraulic Fracturing (PDF) (Report). Committee on Energy and Commerce U.S. House of Representatives. 18 April 2011. Archived from the original (PDF) on 4 October 2013.
  6. ^ a b Healy 2012
  7. ^ Hass, Benjamin (14 August 2012). "Fracking Hazards Obscured in Failure to Disclose Wells". Bloomberg News. Retrieved 27 March 2013.
  8. ^ a b "Developing Onshore Shale Gas and Oil – Facts about 'Fracking'" (PDF). Department of Energy and Climate Change. Retrieved 14 October 2014.
  9. ^ a b Walter, Laura (22 May 2013). "AIHce 2013: Investigating Surface Spills in the Fracking Industry". Penton. EHSToday.
  10. ^ Taherdangkoo, Reza; Tatomir, Alexandru; Anighoro, Tega; Sauter, Martin (February 2019). "Modeling fate and transport of hydraulic fracturing fluid in the presence of abandoned wells". Journal of Contaminant Hydrology. 221: 58–68. Bibcode:2019JCHyd.221...58T. doi:10.1016/j.jconhyd.2018.12.003. PMID 30679092.
  11. ^ Taherdangkoo, Reza; Tatomir, Alexandru; Taylor, Robert; Sauter, Martin (September 2017). "Numerical investigations of upward migration of fracking fluid along a fault zone during and after stimulation". Energy Procedia. 125: 126–135. doi:10.1016/j.egypro.2017.08.093.
  12. ^ a b c Logan, Jeffrey (2012). Natural Gas and the Transformation of the U.S. Energy Sector: Electricity (PDF) (Report). Joint Institute for Strategic Energy Analysis. Retrieved 27 March 2013.
  13. ^ a b c Broomfield 2012
  14. ^ a b c "Man-Made Earthquakes Update". United States Geological Survey. 17 January 2014. Archived from the original on 29 March 2014. Retrieved 30 March 2014.
  15. ^ a b c d "Shale gas extraction: Final report". The Royal Society. 29 June 2012. Retrieved 10 October 2014.
  16. ^ a b Office of Research and Development US Environmental Protection Agency. November 2011 Plan to Study the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources
  17. ^ a b "LOI n° 2011-835 du 13 juillet 2011 visant à interdire l'exploration et l'exploitation des mines d'hydrocarbures liquides ou gazeux par fracturation hydraulique et à abroger les permis exclusifs de recherches comportant des projets ayant recours à cette technique".
  18. ^ a b "Vermont Act 152" (PDF).
  19. ^ Costa, D; Jesus, J; Branco, D; Danko, A; Fiúza, A (June 2017). "Extensive review of shale gas environmental impacts from scientific literature (2010-2015)". Environmental Science and Pollution Research International. 24 (17): 14579–14594. doi:10.1007/s11356-017-8970-0. PMID 28452035. S2CID 36554832.
  20. ^ Public Health England. 25 June 2014 PHE-CRCE-009: Review of the potential public health impacts of exposures to chemical and radioactive pollutants as a result of shale gas extraction ISBN 978-0-85951-752-2
  21. ^ Tatomir, Alexandru; McDermott, Christopher; Bensabat, Jacob; Class, Holger; Edlmann, Katriona; Taherdangkoo, Reza; Sauter, Martin (22 August 2018). "Conceptual model development using a generic Features, Events, and Processes (FEP) database for assessing the potential impact of hydraulic fracturing on groundwater aquifers". Advances in Geosciences. 45: 185–192. Bibcode:2018AdG....45..185T. doi:10.5194/adgeo-45-185-2018.
  22. ^ Currie, Janet; Greenstone, Michael; Meckel, Katherine (13 December 2017). "Hydraulic fracturing and infant health: New evidence from Pennsylvania". Science Advances. 3 (12): e1603021. Bibcode:2017SciA....3E3021C. doi:10.1126/sciadv.1603021. PMC 5729015. PMID 29242825.
  23. ^ a b c d Colborn, Theo; Kwiatkowski, Carol; Schultz, Kim; Bachran, Mary (September 2011). "Natural Gas Operations from a Public Health Perspective". Human and Ecological Risk Assessment. 17 (5): 1039–1056. doi:10.1080/10807039.2011.605662. S2CID 53996198.
  24. ^ "UK Department of Energy and Climate Change. February 2014 "Fracking UK shale: local air quality"" (PDF).
  25. ^ Fernandez, John Michael; Gunter, Matthew. "Hydraulic Fracturing: Environmentally Friendly Practices" (PDF). Houston Advanced Research Center. Archived from the original (PDF) on 27 May 2013. Retrieved 29 December 2012. Cite journal requires |journal= (help)
  26. ^ "Fracking UK shale: water" (PDF). DECC. Archived from the original (PDF) on 14 July 2014. Retrieved 13 November 2014.
  27. ^ a b Pennsylvania, Dept of Environmental Protection. "DEP Study Shows There is Little Potential for Radiation Exposure from Oil and Gas Development" (PDF). Pennsylvania DEP. Retrieved 1 January 2015.
  28. ^ a b Chen, Huan; Carter, Kimberly E. (May 2017). "Modeling potential occupational inhalation exposures and associated risks of toxic organics from chemical storage tanks used in hydraulic fracturing using AERMOD". Environmental Pollution (Barking, Essex: 1987). 224: 300–309. doi:10.1016/j.envpol.2017.02.008. ISSN 1873-6424. PMID 28238366.
  29. ^ McKibben, Bill. "It's Time to Kick Gas". The New Yorker. Retrieved 7 June 2021.
  30. ^ a b IEA (2011). World Energy Outlook 2011. OECD. pp. 91, 164. ISBN 978-92-64-12413-4.
  31. ^ Howarth, Robert W.; Santoro, Renee; Ingraffea, Anthony (13 March 2011). "Methane and the greenhouse-gas footprint of natural gas from shale formations". Climatic Change. 106 (4): 679–690. Bibcode:2011ClCh..106..679H. doi:10.1007/s10584-011-0061-5.
  32. ^ Cathles, Lawrence M.; Brown, Larry; Taam, Milton; Hunter, Andrew (2011). "A commentary on "The greenhouse-gas footprint of natural gas in shale formations"". Climatic Change. 113 (2): 525–535. doi:10.1007/s10584-011-0333-0.
  33. ^ Stephen Leahy (24 January 2012). "Shale Gas a Bridge to More Global Warming". IPS. Archived from the original on 26 January 2012. Retrieved 4 February 2012.
  34. ^ Howarth, Robert W.; Santoro, Renee; Ingraffea, Anthony (1 February 2012). "Venting and leaking of methane from shale gas development: Response to Cathles et al". Climatic Change. 113 (2): 537–549. Bibcode:2012ClCh..113..537H. doi:10.1007/s10584-012-0401-0.
  35. ^ a b Allen, David T.; Zavala-Araiza, Daniel; Lyon, David R.; Alvarez, Ramón A.; Barkley, Zachary R.; Brandt, Adam R.; Davis, Kenneth J.; Herndon, Scott C.; Jacob, Daniel J.; Karion, Anna; Kort, Eric A.; Lamb, Brian K.; Lauvaux, Thomas; Maasakkers, Joannes D.; Marchese, Anthony J.; Omara, Mark; Pacala, Stephen W.; Peischl, Jeff; Robinson, Allen L.; Shepson, Paul B.; Sweeney, Colm; Townsend-Small, Amy; Wofsy, Steven C.; Hamburg, Steven P. (13 July 2018). "Assessment of methane emissions from the U.S. oil and gas supply chain". Science Magazine. 361 (6398): 186–188. Bibcode:2018Sci...361..186A. doi:10.1126/science.aar7204. PMC 6223263. PMID 29930092.
  36. ^ Trembath, Alex; Luke, Max; Shellenberger, Michael; Nordhaus, Ted (June 2013). Coal Killer: How Natural Gas Fuels the Clean Energy Revolution (PDF) (Report). Breakthrough institute. p. 22. Retrieved 2 October 2013.
  37. ^ Schneising, Oliver (2014). "Remote sensing of fugitive methane emissions from oil and gas production in North American tight geologic formations". Earth's Future. 2 (10): 548–558. Bibcode:2014EaFut...2..548S. doi:10.1002/2014EF000265.
  38. ^ Bradbury, James; Obeiter, Michael (6 May 2013). "5 Reasons Why It's Still Important To Reduce Fugitive Methane Emissions". World Resources Institute. Retrieved 2 October 2013.
  39. ^ "Methane research series: 16 studies". Environmental Defense Fund. Retrieved 24 April 2019.
  40. ^ Andrews, Anthony; et al. (30 October 2009). Unconventional Gas Shales: Development, Technology, and Policy Issues (PDF) (Report). Congressional Research Service. pp. 7, 23. Retrieved 22 February 2012.
  41. ^ a b Abdalla, Charles W.; Drohan, Joy R. (2010). Water Withdrawals for Development of Marcellus Shale Gas in Pennsylvania. Introduction to Pennsylvania's Water Resources (PDF) (Report). The Pennsylvania State University. Retrieved 16 September 2012. Hydrofracturing a horizontal Marcellus well may use 4 to 8 million gallons of water, typically within about 1 week. However, based on experiences in other major U.S. shale gas fields, some Marcellus wells may need to be hydrofractured several times over their productive life (typically five to twenty years or more)
  42. ^ GWPC & ALL Consulting 2012
  43. ^ a b Arthur, J. Daniel; Uretsky, Mike; Wilson, Preston (5–6 May 2010). Water Resources and Use for Hydraulic Fracturing in the Marcellus Shale Region (PDF). Meeting of the American Institute of Professional Geologists. Pittsburgh: ALL Consulting. p. 3. Retrieved 9 May 2012.
  44. ^ Cothren, Jackson. Modeling the Effects of Non-Riparian Surface Water Diversions on Flow Conditions in the Little Red Watershed (PDF) (Report). U. S. Geological Survey, Arkansas Water Science Center Arkansas Water Resources Center, American Water Resources Association, Arkansas State Section Fayetteville Shale Symposium 2012. p. 12. Retrieved 16 September 2012. ...each well requires between 3 and 7 million gallons of water for hydraulic fracturing and the number of wells is expected to grow in the future
  45. ^ Faucon, Benoît (17 September 2012). "Shale-Gas Boom Hits Eastern Europe". WSJ.com. Retrieved 17 September 2012.
  46. ^ Nicot, Jean-Philippe; Scanlon, Bridget R. (9 March 2012). "Water Use for Shale-Gas Production in Texas, U.S." Environmental Science & Technology. 46 (6): 3580–3586. Bibcode:2012EnST...46.3580N. doi:10.1021/es204602t. PMID 22385152.
  47. ^ "Tyndall center report" (PDF). Archived from the original (PDF) on 1 August 2014. Retrieved 1 November 2014.
  48. ^ Upton, John (15 August 2013). "Fracking company wants to build new pipeline — for water". Grist. Retrieved 16 August 2013.
  49. ^ Urbina, Ian (30 December 2011). "Hunt for Gas Hits Fragile Soil, and South Africans Fear Risks". The New York Times. Retrieved 23 February 2012. Covering much of the roughly 800 miles between Johannesburg and Cape Town, this arid expanse – its name [Karoo] means "thirsty land" – sees less rain in some parts than the Mojave Desert.
  50. ^ Staff (16 June 2013). "Fracking fuels water battles". Politico. Associated Press. Retrieved 26 June 2013.
  51. ^ Life Cycle Analysis of Natural Gas Extraction and Power Generation, NREL, DOE/NETL-2014-1646, 29 May 2014.
  52. ^ a b "Texas Water Report: Going Deeper for the Solution". Texas Comptroller of Public Accounts. Archived from the original on 22 February 2014. Retrieved 11 February 2014.
  53. ^ Bullis, Kevin (22 March 2013). "Skipping the Water in Fracking". MIT Technology Review. Retrieved 30 March 2014.
  54. ^ Sider, Alison; Lefebvre, Ben (20 November 2012). "Drillers Begin Reusing 'Frack Water.' Energy Firms Explore Recycling Options for an Industry That Consumes Water on Pace With Chicago". The Wall Street Journal. Retrieved 20 October 2013.
  55. ^ Diamanti-Kandarakis, Evanthia; Bourguignon, Jean-Pierre; Giudice, Linda C.; Hauser, Russ; Prins, Gail S.; Soto, Ana M.; Zoeller, R. Thomas; Gore, Andrea C. (June 2009). "Endocrine-disrupting chemicals: an Endocrine Society scientific statement". Endocrine Reviews. 30 (4): 293–342. doi:10.1210/er.2009-0002. PMC 2726844. PMID 19502515.
  56. ^ a b Meyer, Denise (24 October 2016). "Fracking Linked to Cancer-Causing Chemicals, New YSPH Study Finds". Yale School of Public Health.
  57. ^ "EU Groundwater directive". 27 December 2006.
  58. ^ a b Engelder, Terry; Cathles, Lawrence M.; Bryndzia, L. Taras (September 2014). "The fate of residual treatment water in gas shale". Journal of Unconventional Oil and Gas Resources. 7: 33–48. doi:10.1016/j.juogr.2014.03.002.
  59. ^ a b c Arthur, J. Daniel; Langhus, Bruce; Alleman, David (2008). An overview of modern shale gas development in the United States (PDF) (Report). ALL Consulting. p. 21. Retrieved 7 May 2012.
  60. ^ a b Weinhold, Bob (19 September 2012). "Unknown Quantity: Regulating Radionuclides in Tap Water". Environmental Health Perspectives. 120 (9): A350–6. doi:10.1289/ehp.120-a350. PMC 3440123. PMID 23487846. Examples of human activities that may lead to radionuclide exposure include mining, milling, and processing of radioactive substances; wastewater releases from the hydraulic fracturing of oil and natural gas wells... Mining and hydraulic fracturing, or "fracking", can concentrate levels of uranium (as well as radium, radon, and thorium) in wastewater...
  61. ^ Staff. Waste water (Flowback)from Hydraulic Fracturing (PDF) (Report). Ohio Department of Natural Resources. Retrieved 29 June 2013. Most of the water used in fracturing remains thousands of feet underground, however, about 15-20 percent returns to the surface through a steel-cased well bore and is temporarily stored in steel tanks or lined pits. The wastewater which returns to the surface after hydraulic fracturing is called flowback
  62. ^ Hopey, Don (1 March 2011). "Gas drillers recycling more water, using fewer chemicals". Pittsburgh Post-Gazette. Retrieved 27 March 2013.
  63. ^ Litvak, Anya (21 August 2012). "Marcellus flowback recycling reaches 90 percent in SWPA". Pittsburgh Business Times. Retrieved 27 March 2013.
  64. ^ "Monitor: Clean that up". The Economist. 30 November 2013. Retrieved 15 December 2013.
  65. ^ David Caruso (3 January 2011). "44,000 Barrels of Tainted Water Dumped Into Neshaminy Creek. We're the only state allowing tainted water into our rivers". NBC Philadelphia. Associated Press. Retrieved 28 April 2012.
  66. ^ a b c Urbina, Ian (26 February 2011). "Regulation Lax as Gas Wells' Tainted Water Hits Rivers". The New York Times. Retrieved 22 February 2012.
  67. ^ Shores, A; Laituri, M; Butters, G (2017). "Produced Water Surface Spills and the Risk for BTEX and Naphthalene Groundwater Contamination". Water Air Soil Pollut. 228 (11): 435. Bibcode:2017WASP..228..435S. doi:10.1007/s11270-017-3618-8. S2CID 103994435.
  68. ^ Energy Institute (February 2012). Fact-Based Regulation for Environmental Protection in Shale Gas Development (PDF) (Report). University of Texas at Austin. p. ?. Retrieved 29 February 2012.
  69. ^ "COMMISSION RECOMMENDATION of 22 January 2014 on minimum principles for the exploration and production of hydrocarbons (such as shale gas) using high-volume hydraulic fracturing". EUR-LEX. 8 February 2014. Retrieved 1 November 2014. Cite journal requires |journal= (help)
  70. ^ European, Commission. "Environmental Aspects on Unconventional Fossil Fuels". Retrieved 27 October 2014.
  71. ^ "Fracking UK shale : local air quality" (PDF). DECC. UK Govt. Retrieved 27 October 2014.
  72. ^ "Fracking UK shale : water" (PDF). DECC. UK Govt. Archived from the original (PDF) on 14 July 2014. Retrieved 27 October 2014.
  73. ^ Osborn, Stephen G.; Vengosh, Avner; Warner, Nathaniel R.; Jackson, Robert B. (17 May 2011). "Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing". Proceedings of the National Academy of Sciences. 108 (20): 8172–8176. Bibcode:2011PNAS..108.8172O. doi:10.1073/pnas.1100682108. PMC 3100993. PMID 21555547.
  74. ^ full report
  75. ^ a b Osborn, Stephen G.; Vengosh, Avner; Warner, Nathaniel R.; Jackson, Robert B. (17 May 2011). "Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing". Proceedings of the National Academy of Sciences of the United States of America. 108 (20): 8172–8176. Bibcode:2011PNAS..108.8172O. doi:10.1073/pnas.1100682108. PMC 3100993. PMID 21555547.
  76. ^ Moniz, Jacoby & Meggs 2012
  77. ^ Ehrenburg, Rachel (25 June 2013). "News in Brief: High methane in drinking water near fracking sites. Well construction and geology may both play a role". Science News. Retrieved 26 June 2013.
  78. ^ Detrow, Scott (9 October 2012). "Perilous Pathways: How Drilling Near An Abandoned Well Produced a Methane Geyser". StateImpact Pennsylvania. NPR. Retrieved 29 June 2013.
  79. ^ Molofsky, L. J.; Connor, J. A.; Shahla, K. F.; Wylie, A. S.; Wagner, T. (5 December 2011). "Methane in Pennsylvania Water Wells Unrelated to Marcellus Shale Fracturing". Oil and Gas Journal. 109 (49): 54–67. (subscription required).
  80. ^ "Gasland Correction Document" (PDF). Colorado Oil & Gas Conservation Commission. Archived from the original (PDF) on 5 September 2013. Retrieved 7 August 2013.
  81. ^ "Fracking Acquitted of Contaminating Groundwater". Science. 335 (6071): 898. 24 February 2012. doi:10.1126/science.335.6071.898.
  82. ^ Erik Stokstad (16 February 2012). "Mixed Verdict on Fracking". Science Now. Archived from the original on 26 April 2012. Retrieved 12 May 2012.
  83. ^ a b Vidic, R. D.; Brantley, S. L.; Vandenbossche, J. M.; Yoxtheimer, D.; Abad, J. D. (16 May 2013). "Impact of Shale Gas Development on Regional Water Quality". Science. 340 (6134): 1235009. doi:10.1126/science.1235009. PMID 23687049. S2CID 32414422.
  84. ^ Staff. "Radon in Drinking Water: Questions and Answers" (PDF). US Environmental Protection Agency. Retrieved 7 August 2012.
  85. ^ Heather Smith (7 March 2013). "County's potential for fracking is undetermined". Environment / Pollution. Discover Magazine. Archived from the original on 5 August 2014. Retrieved 11 August 2013.
  86. ^ Lubber, Mindy (28 May 2013). "Escalating Water Strains In Fracking Regions". Forbes. Retrieved 20 October 2013.
  87. ^ Linda Marsa (1 August 2011). "Fracking Nation. Environmental concerns over a controversial mining method could put America's largest reservoirs of clean-burning natural gas beyond reach. Is there a better way to drill?". Environment / Pollution. Discover Magazine. Retrieved 5 August 2011.
  88. ^ White, Jeremy; Park, Haeyoun; Urbina, Ian; Palmer, Griff (26 February 2011). "Toxic Contamination From Natural Gas Wells". The New York Times.
  89. ^ "Radioactive Waste from Oil and Gas Drilling" (PDF). United States Environmental Protection Agency. April 2006. Retrieved 11 August 2013.
  90. ^ McMahon, Jeff (24 July 2013). "Strange Byproduct Of Fracking Boom: Radioactive Socks". Forbes. Retrieved 28 July 2013.
  91. ^ "Strategic Environmental Assessment for Further Onshore Oil and Gas Licensing" (PDF). Department of Energy and Climate Change. June 2014. p. ?. Retrieved 11 November 2014.
  92. ^ Moran, Matthew D. (2015). "Habitat Loss and Modification Due to Gas Development in the Fayetteville Shale". Environmental Management. 55 (6): 1276–1284. Bibcode:2015EnMan..55.1276M. doi:10.1007/s00267-014-0440-6. PMID 25566834. S2CID 36628835.
  93. ^ Moran, Matthew D (2017). "Land-use and ecosystem services costs of unconventional US oil and gas development". Frontiers in Ecology and the Environment. 15 (5): 237–242. doi:10.1002/fee.1492.
  94. ^ Bennet, Les; et al. "The Source for Hydraulic Fracture Characterization". Oilfield Review (Winter 2005/2006): 42–57. Archived from the original (PDF) on 25 August 2014. Retrieved 30 September 2012.
  95. ^ a b Zoback, Kitasei & Copithorne 2010
  96. ^ "Fox Creek fracking operation closed indefinitely after earthquake". CBC News Edmonton. 12 January 2016. Retrieved 2 September 2016.
  97. ^ "Alberta town rattled by 2nd earthquake this year". CBC News. 14 June 2015. Retrieved 29 December 2016.
  98. ^ "Fracking likely cause of earthquakes in northern Alberta". CBC News. CBC News. 30 January 2015. Retrieved 29 December 2016.
  99. ^ Trumpener, Betsy (16 December 2015). "Earthquake in Northern B.C. caused by fracking, says oil and gas commission". CBC News. Retrieved 29 December 2016.
  100. ^ Trumpener, Betsy (26 August 2015). "Fracking triggered 2014 earthquake in northeastern B.C.:Quake one of world's largest ever triggered by hydraulic fracturing". CBC News. Retrieved 29 December 2016.
  101. ^ BC Oil and Gas Commission (August 2012). "Investigation of Observed Seismicity in the Horn River Basin" (PDF). BC Oil and Gas Commission. Retrieved 29 December 2016.
  102. ^ Davies, Richard; Foulger, Gillian; Bindley, Annette; Styles, Peter (2013). "Induced seismicity and hydraulic fracturing for the recovery of hydrocarbons" (PDF). Marine and Petroleum Geology. 45: 171–85. doi:10.1016/j.marpetgeo.2013.03.016.
  103. ^ Skoumal, Robert J.; Brudzinski, Michael R.; Currie, Brian S. (2015). "Earthquakes Induced by Hydraulic Fracturing in Poland Township, Ohio". Bulletin of the Seismological Society of America. 105 (1): 189–97. Bibcode:2015BuSSA.105..189S. doi:10.1785/0120140168.
  104. ^ British Geological Survey. "Earthquakes induced by Hydraulic Fracturing Operations near Blackpool, UK". earthquakes.bgs.ac.uk. Retrieved 29 December 2016.
  105. ^ a b Rachel Maddow, Terrence Henry (7 August 2012). Rachel Maddow Show: Fracking waste messes with Texas (video). MSNBC. Event occurs at 9:24 - 10:35. Retrieved 30 September 2012.
  106. ^ Soraghan, Mike (29 March 2012). "'Remarkable' spate of man-made quakes linked to drilling, USGS team says". EnergyWire. E&E. Retrieved 9 November 2012.
  107. ^ Henry, Terrence (6 August 2012). "How Fracking Disposal Wells Are Causing Earthquakes in Dallas-Fort Worth". State Impact Texas. NPR. Retrieved 9 November 2012.
  108. ^ Ellsworth, W. L.; Hickman, S.H.; McGarr, A.; Michael, A. J.; Rubinstein, J. L. (18 April 2012). Are seismicity rate changes in the midcontinent natural or manmade?. Seismological Society of America 2012 meeting. San Diego, California: Seismological Society of America. Archived from the original on 25 August 2014. Retrieved 23 February 2014.
  109. ^ Redmond, H; Faulkner, K (2013). "Submission on the Camden gas project stage 3 northern expansion". Doctors for the Environment Australia.
  110. ^ Coram, A; Moss, J; Blashki, G (2013). "Submission on the Camden gas project stage 3 northern expansion". The Medical Journal of Australia. 4: 210–213.
  111. ^ "What it looks like Noise chapter". UKOOG. Retrieved 11 November 2014.
  112. ^ Frederick J. Herrmann, Federal Railroad Administration, letter to American Petroleum Institute, 17 July 2013, p.4.
  113. ^ Sangaramoorthy, Thurka; Jamison, Amelia M.; Boyle, Meleah D.; Payne-Sturges, Devon C.; Sapkota, Amir; Milton, Donald K.; Wilson, Sacoby M. (February 2016). "Place-based perceptions of the impacts of fracking along the Marcellus Shale". Social Science & Medicine. 151: 27–37. doi:10.1016/j.socscimed.2016.01.002. PMID 26773295.
  114. ^ Hirsch, Jameson K.; Bryant Smalley, K.; Selby-Nelson, Emily M.; Hamel-Lambert, Jane M.; Rosmann, Michael R.; Barnes, Tammy A.; Abrahamson, Daniel; Meit, Scott S.; GreyWolf, Iva; Beckmann, Sarah; LaFromboise, Teresa (31 July 2017). "Psychosocial Impact of Fracking: a Review of the Literature on the Mental Health Consequences of Hydraulic Fracturing". International Journal of Mental Health and Addiction. 16 (1): 1–15. doi:10.1007/s11469-017-9792-5. S2CID 44053884.
  115. ^ Editors, ParisTech Review 28 March 2014 Is it really possible to enforce the precautionary principle? Archived 1 December 2016 at the Wayback Machine
  116. ^ Williams, Laurence, John "Framing fracking: public responses to potential unconventional fossil fuel exploitation in the North of England", Durham thesis, Durham University, 2014
  117. ^ Royal Society 2012
  118. ^ Burton, G. Allen; Basu, Niladri; Ellis, Brian R.; Kapo, Katherine E.; Entrekin, Sally; Nadelhoffer, Knute (1 August 2014). "Hydraulic "Fracking": Are surface water impacts an ecological concern?" (PDF). Environmental Toxicology and Chemistry. 33 (8): 1679–1689. doi:10.1002/etc.2619. hdl:2027.42/108102. ISSN 1552-8618. PMID 25044053.
  119. ^ Vidic, R. D.; Brantley, S. L.; Vandenbossche, J. M.; Yoxtheimer, D.; Abad, J. D. (17 May 2013). "Impact of Shale Gas Development on Regional Water Quality". Science. 340 (6134): 1235009. doi:10.1126/science.1235009. ISSN 0036-8075. PMID 23687049. S2CID 32414422.
  120. ^ Stringfellow, William T.; Domen, Jeremy K.; Camarillo, Mary Kay; Sandelin, Whitney L.; Borglin, Sharon (30 June 2014). "Physical, chemical, and biological characteristics of compounds used in hydraulic fracturing". Journal of Hazardous Materials. 275: 37–54. doi:10.1016/j.jhazmat.2014.04.040. ISSN 0304-3894. PMID 24853136.