Also in this series:
Shale and water: Water requirements could pose challenges to fracking
Shale and water: Is there a risk of water contamination?
Throughout the entire fracking lifecycle there are risks associated both with the quantity of water needed and the potential contamination of drinking water supply with methane gas and harmful chemicals.
Water UK, which represents all major water suppliers, is calling for “greater clarity from the shale gas industry on what its water needs are really going to be and a true assessment of the impacts.”
Dr Jim Marshall, Policy and Business Adviser at Water UK said in his July 17 speech at UK Shale 2013: “If we get it wrong then water has the potential to stop the industry in its tracks.”
Energydesk takes a look at what fracking means for water quantity.
What are the main concerns?
According to a study by the United Nations Environment Programme (UNEP), “spills or leaks can … occur during the transport, mixing and storage of the water and flowback”.
Highlighted by Water UK and an AMEC report for the Department of Energy and Climate change, these risks include:
- Contamination of surface water by runoff from construction activities, spills and leaks of drilling muds, and/or from poorly managed waste water or handling of chemicals
- Contamination of groundwater by pollutants (including gas) released from the well due to well integrity failure, spillage of stored wastewaters and/or chemicals, from fracturing running through geology
- Competition for water resources
- Tertiary risks associated with traffic movements or drilling in general
(Picture from UNEP report)
How much water does fracking need?
Fracking is a highly water-intensive process, requiring 50 to 100 times more water than the extraction of conventional gas.
With fracking fluid typically consisting of 99 per cent water (with the rest made up of sand and chemicals), it’s an understatement to say that water plays a key role in the extraction process.
It’s difficult to estimate exactly how much water is required, as it varies per well.
The amount of water also depends on a series of different variables including the geology and density of the rock, the depth and horizontal distance of the well, as well as the number of times the well is fracked.
The most recent estimate by DECC puts the amount of water required per well between 10,000 and 30,000 cubic metres.
The US Environmental Protection Agency (EPA) estimates that the water needed to drill a horizontal shale gas well ranges between 7,600 cubic metres and 19,000 cubic metres.
Cuadrilla Resources says that it is “too early to say” exactly how much water would be needed. However, according to the IoD report sponsored by Cuadrilla, it estimates water use at 10,000 to 13,600 cubic metres per lateral.
In the U.S. for example, it’s been calculated that for approximately 1500 horizontal wells drilled into the Marcellus Shale in 2011, about 45,000 to 76,000 cubic metres were used per day.
How much water will be needed in Britain?
Recently, the British Geological Survey revealed that there is an estimated 1300trn cubic feet worth of shale gas trapped in the rocks beneath Lancashire.
Assuming that 10 per cent of the shale can be extracted, Energydesk calculates that this would require 680 million cubic metres of water.
This calculation is based on the figures outlined in the IoD report, which estimate that each well would use 13,600 cubic metres of water - equal to the Eagle Ford wells in Texas - as well as the assumption that around 50,000 wells or laterals would be required, if every well was equivalent to the most productive wells in the US, found in the Haynesville Sabine Platform.
Effectively, this is equivalent to the annual water consumption of 12.4 million UK household and produce (though it’s important to note this would, presumably, happen over decades).
This is compared to estimates by Water UK that, based on a demand of a 1000 well field, peak water demand could be about 2,000 cubic metres per day during fracturing. This is equivalent to the water use of 13,000 people per day. Their estimates expect a total demand of about 20,000 cubic metres per year.
Finally, the IoD report estimates that water use from fracking will peak at 5.4 million cubic metres of water given a peak of 50 rigs drilling and fracturing 400 laterals a year.
Where will this water come from?
According to Cuadrilla’s website, United Utilities in Lancashire is currently its sole water provider.
About 90 per cent of all water supplied by United Utilities (not just to Cuadrilla) comes from rivers and reservoirs as opposed to groundwater sources. However, in United Utilities’ Draft Resources Management Plan 2013, they state that after evaluating the potential impacts of climate change, surface water sources, such as rivers, are estimated to reduce by six per cent by 2040.
(Map of water availability in England from Amec SEA report to DECC)
Will fracking impact the amount of water available for agriculture or household use?
There is a medium probability according to the Environment Agency (EA) that acquiring water for fracking will impact on water supplies for the natural environment as well as increasing competition for the resource.
A report by UNEP states that “the needs of water for exploitation and the depletion of aquifers has (and will) create conflicts in water usages. Notably, competition with agricultural users is likely to be a serious issue.”
The EA echoes UNEP, classifying the consequences from water acquisition as high-risk. These consequences, according to their latest report, are: “damage to local ecosystems and interruptions either to the supply to other industrial water consumers or the shale gas operators themselves.”
The UNEP report also warns that fracking should not occur in areas of water scarcity, high population density, or in areas where it can impact agricultural production. However, according to the DECC report, there is no set minimum distance for any industrial activity from populated areas in the UK.
In May, sustainability NGO Ceres issued a report revealing that a significant portion of US fracking is occurring in areas that are experiencing severe water stress such as Texas and Colorado, which are currently in the middle of a drought.
Based on data collected from over 25,000 shale oil and gas wells in the US by FracFocus.org and water stress indicator maps developed by the World Resources Institute, the report is part of a larger effort by Ceres to analyse the water risks across the entire fracking lifecycle in North America.
“Climate change will only exacerbate water supply and demand imbalances,” the report warns, “shale energy development highlights the fact that our water resources were already vulnerable before additional demands were introduced.”
A prime example of this was reported by the Guardian in August revealing that in Texas, the current drought combined with fracking could lead to about 30 towns running out of water by the end of the year.
In Dr Jim Marshall’s speech on July 17, he points out that Britain too, has undergone water stress recently citing three consecutive dry winters and low groundwater levels which induced drought and water restrictions.
“The IoD report notes that they expected shale gas ‘production to be in parts of the country with low water stresses’. This is not true,” Marshall said of the report which only looks at shale production in northern England.
Marshall pointed out that in the south east of England water stress “is a real concern”.
The International Energy Agency’s (IEA) recent report confirms fears over water stress, stating: “In areas of water scarcity, either now or due to climate change, the extraction of water for drilling and hydraulic fracturing may encounter serious constraints.”
United Utilities has assured residents that in situations of increased water stress, such as a drought, it would be Cuadrilla Resources who would be the first to have its water supply reduced, not the residents.
In their Draft Water Resources Management Plan, United Utilities state that, with regards to fracking, they do “not consider that the provision of water for fracking would impact on the water resources available across our region, but we will assess each request on a site by site basis to ensure that the supplies to our existing customers are not affected.”
By law, water companies are required to produce a water resources management plan every five years. These plans must demonstrate how demand for water will be managed and met over a 25 year period.
It’s interesting to note though, that United Utilities is in talks with Cuadrilla about exploring for shale gas on some of the 141,000 acres it owns in northwest England.
What about the flowback water?
According to the Cuadrilla Resources website, in the UK between 20-40 per cent of the water used during the fracturing process flows back to the surface during the first few weeks. The rest of the water remains underground, some of which resurfaces during the well’s overall lifetime.
Flowback water is characterised as a mining waste and requires a permit for safe disposal. If the waste water is improperly treated then it risks entering and contaminating the surface waters and/or the groundwater.
The risk of a surface spill of flowback water - which could occur due to defective pipes or storage tanks, or the transfer of fluids from storage to tanker for example - is classified as medium according to the Environment Agency.
If the flowback water is not recycled for future use, there are several methods of disposal: re-injecting it deep within the earth; decontaminating it and then disposing in surface water body; disposing of directly on the land; on-site treatment (or direct removal for treatment elsewhere) and then disposing to a licensed waste treatment and disposal facility; and disposing of it - with permission - to foul sewer.
It should be noted that the DECC report states “large scale re-injection of frac disposal fluids poses a recognised earthquake risk”.
Can we reduce the total amount of water used?
The short answer is no.
“Not without some breakthrough,” said Dr Anthony Ingraffea, professor of engineering at Cornell and co-author of the study which established fracking’s greenhouse-gas footprint.
“Is there going to be some magic solution, some miracle new technique for getting gas or oil out of shale that doesn’t require tens of millions of litres of water each time for each well? Good luck,” said Ingraffea, who’s been involved in hydraulic fracturing for 30 years.
According to the Royal Society, technology does exist for waterless onshore fracking fluid. For example, gelled liquid petroleum gas (LPG) has been developed by GasFrac in Alberta, however it remains in its infancy and there’s concerns surrounding the safety and cost of such technology.
More practicably, there is the option of using recycled water, but even this only goes so far in reducing the total amount of water needed.
The Ceres report stresses that “overall water recycling and the use of nonfreshwater sources must increase considerably to make a significant impact.”
Yet it continues on, stating that “it is important to realise that recycling can only go so far in solving water sourcing problems since much of the water injected remains in the formation.”
In a statement received from Cuadrilla, they said: “In the development phase, [Cuadrilla’s] intention is to recycle flowback water at each site and this would significantly reduce water usage. However, current regulations mean that the company would be unable to do so at present.”
