We have received a number of questions on the various aspects of environmental impact, including questions about how shale gas affects:
- Water in underground aquifers and at the surface
- Climate change and efforts to increase our use of renewable energy
- Gas emissions from the extraction process
According to the joint Royal Society and the Royal Academy of Engineering report, at the time the report was produced, the available evidence indicates that the risk of water contamination in the UK is very low provided that shale gas extraction takes place at depths of many hundreds of metres or several kilometres – which would be the case here1.
The Chartered Institution of Water and Environmental Management (CIWEM) also agrees that risks to groundwater quality are generally considered to be low in the UK where the shale rock in question often exists at considerable depths below aquifers - meaning that the gas would have to migrate many hundreds of metres between the source rock and overlaying aquifers.2
Dr James Verdon of the University of Bristol said: “Multiple studies in the USA have confirmed that the hydraulic fracturing process itself has not caused contamination of aquifers. That’s not to say there have been zero accidents or incidents in the USA, but that on the few occasions that problems have been recorded, it’s been due to other drilling-related issues, and not due to fracking.”
There have been a few examples of water contamination in the US - a recent report from Ohio University found some instances of water contaminated with natural gas. However, this was caused by faulty wells, not by the hydraulic fracturing (“fracking”) process3. This indicates that water contamination can be prevented with strict regulation from Government and good well design and construction which in the UK is overseen by the Health and Safety Executive.
Also relevant to this question is whether there is any risk of surface spills at shale well sites, and whether such spills could contaminate water. The Environment Agency has investigated this issue and judged that the environmental risks at each individual stage of exploratory shale gas operation, provided that there is proper management and regulation, are “low”4.
Professor Richard Selley from Imperial College London said: “Notorious cases of alleged contamination in the US, such as at Dimock in Pennsylvania (where brown water was used to illustrate contamination by fracking fluids) was revealed to be naturally occurring iron oxides in the ground water. The UK has a far more robust regulatory process for granting permission and monitoring all drilling operations than those of the USA.”
CO2 emissions and renewables
The Government’s Department of Energy and Climate Change says that UK shale gas would have a lower carbon footprint than the imported liquefied natural gas it would replace, and a carbon footprint around half as large as that of coal.5
It is also important to note that investment in shale gas does not come at the expense of investment in renewable energy and it’s not a case of one or the other. Stephen Tindale, the former director of Greenpeace, said in May 2014 that climate campaigners should support fracking for shale gas. He says that the reason for this is that the use of shale gas would enable the UK to reduce the burning of coal.6
The UK’s Committee on Climate Change, which advises the Government on meeting the country’s carbon reduction targets, has concluded:
“UK shale gas production would reduce our dependence on imports and help to meet the UK’s continued gas demand, for example in industry and for heat in buildings, even as we reduce consumption by improving energy efficiency and switching to low-carbon technologies.”7
The United Nations’ Intergovernmental Panel on Climate Change (IPCC) Working Group 35th Assessment Report, published in April 2014, said that avoiding climate change will mean reducing coal use before reducing the use of gas. This is because generating electricity from gas produces about half of the emissions than generating electricity from coal. However, they concluded more research needs to be done on methane released into the atmosphere during shale gas extraction8.
Professor Richard Selley from Imperial College London said: “The Government’s energy policy is to solve the ‘Trilemma’ for providing energy that is economic, that does least damage to the environment, and whose source is secure. It supports hydraulic fracturing for shale gas as part of a balanced mix of diverse energy sources, including nuclear and renewables. All 3 major parties support this solution to the energy trilemma.”
Gas flaring and emissions
It is important to prevent methane from escaping into the atmosphere during extraction. To ensure the process of energy production is as efficient as possible, as much methane as possible should be converted into electricity and heat. In addition, according to the US Environmental Protection Agency: “Pound for pound, the comparative impact of methane on climate change is over 20 times greater than CO2 over a 100-year period.”9
To safeguard the environment, the government’s Department of Energy and Climate Change (DECC) insists that operators must minimise the release of gas into the atmosphere and, when gas can’t be economically used, it must be captured and “flared” to reduce its global warming emissions’.10 Beyond exploration, operators will have a commercial incentive not to flare gas, as the gas could otherwise be sold.
It is also important that methane does not leak from the well, and escape into the environment that way. Simon Talbot, Managing Director of Ground Gas Solutions, told us that:
“To ensure that methane leakage from a well is prevented, the existing methane concentrations in the near surface soils and groundwater are measured before operations commence as part of a Baseline Monitoring Survey.
“Methane leakage from a well can then be prevented by a well construction design that includes multiple layers of casing which is checked by the Health and Safety Executive and then integrity tested before operation commences. Then during and after operations independent environmental monitoring will be carried out to check that no leakage has occurred.
“UKOOG (the representative body for the UK onshore oil and gas industry) is developing guidelines for comprehensive baseline monitoring of soil, air and water before and during operations. These will be mandatory for UKOOG members. These guidelines will be published soon. Once these guidelines have been published, UKOOG will develop guidelines for the monitoring of the local environment after wells have been decommissioned.”
With regards to good well design, Professor Richard Selley of Imperial College London told us that: “There are generally three cylinders of steel casing cemented over the interval of the aquifer and, when a well is decommissioned, it is plugged and cemented to prevent the release and escape of methane and any other fluids.”
Finally, the shale gas industry in the UK is developing “green completion” based on industry best practice, to reduce the emissions of gases into the air, and this is emphasised in UKOOG’s “UK Onshore Shale Gas Well Guidelines”11. This involves using specialist equipment to collect and separate the initial flow of water, sand and gas, so the gas can be prevented from escaping. According to Professor David MacKay, (DECC’s Chief Scientific Advisor), and Dr Timothy Stone (the Senior Advisor to the Secretary of State), “green completions” should be adopted at all stages following exploration.12 According to the Government’s Department of Energy and Climate Change “Green completions and flaring can reduce methane emissions by as much as 95% versus venting straight into the atmosphere.”13
11 UKOOG, UK Onshore Shale Gas Well Guidelines http://www.ukoog.org.uk/images/ukoog/pdfs/ShaleGasWellGuidelines.pdf
Thank you to everyone who submitted questions similar to the one above. Questions we have received which are similar are shown below:
- How will it effect the environment after the fracking has taken place
- Will tracking damage the enviroment
- Is it safe on local environment? Can this be guaranteed. Will it have a governing body to make sure it stays safe? Will it be regulated?
- Is shale gas obtained by "fracking" going to: A: Reduce pollutant emmissions, B: Reduce consumer costs; C: Obviate foreign imports of fuel; D: Make more profits for oil/gas industry
- Carbon fuel emissions are destroying our planet, so why exacerbate it with more through fracking?
- All environmental issues I am concerned about, especially water supply, earth tremors, etc
- Is fracking safe for the environment?
- What environmental effects will shale gas drilling have. What sort of revenue will it generate?
- How do we justify going ahead with fracking when we are still not full aware of the damage to our environment
- Are we friendly to the environment?
- Is it harmful to the environment
- Is it good for environment?
- Very little knowledge - not aware of impact on environment
- Implications for environment.
- How dangerous to the environment is fracking? Long term effects.
- Is it safe for the environment? What is fracking?
- Fracking is fine as long as it's profitable. Is it environment friendly too?
- I understand the ecconomic benefits but not the enviromental costs.
- What is the long term damage on the environment?
- What about long term effects on the enviroment?
- Is it going to damage the countryside and environment?
- How harmful is additional burning of fossel fuel going to be to the environment? Where is the replacement water coming from? How will you cleanse and dispose of dirty water after fracking?
- It must be affecting the ground and environment where it's taking place?
- What loss to the environment would there be and the cost to fix this?
- How can you guarantee that this heavy drilling will be safe for the environment in the long term? Earthquakes? Sink holes?
- What benefit will it be for householders? What effect on environment?
- What impact has it had on the environment where it has already been done?
- What potential damage is there to the environment? Is there any potential pollution in the natural springs?
- What are the implications for the environment and surrounding villages & towns.
- I disagree with fracking because I believe it will cause environmental problems. I dont believe the answers from the fracking industry are true. Is this right?
- Why are you continuing with fracking when quite clearly it is unsafe and will cause major pollution
- I'm concerned that fracking will be environmental hazard and possible cause water (drilling) contamination. What's the likelyhood?
- Is it sensible to be fracturing bed rock so close to nuclear power stations? What about pollution and traffic?
- Is there any way you can prevent any damage to the local environment?
- Is fracking going to happen in my area? Lincolnshire. How much research has been done given the negative impact seen in the USA? How are companies going to limit environmental damage to locations and communities? Will it impact house prices? Will it impact gas bills?
- Are you aware of USA evidence that fugitive methane emissions during and after extraction prove the gas is as bad as coal for climate change?
- Not sure of environmental consequences.
- What is shale gas? Is it good for the environment? Is it expensive?
- Enviromentaly safe or not? Why do we need it?
- Is it going to cost me anything? In tax is this going to create jobs? How profitable is it going to be to the rich and the poor? How is it going to effect pollution? Why do we need it ? What is the benefit?