A report published by the International Energy Agency (http://www.iea.org/) entitled: Golden Rules for a Golden Age of Gas: World Energy Outlook, Special Report on Unconventional Gas, 2012, has stated that each fracking well can require up to twenty thousand cubic meters of water, per well, per day....that is a lot of water...if you multiply this by the number of wells...and then multiply this by the number of days the fracking well will be in operation....That is a lot of water! It also makes hydraulic fracturing the most water intensive energy resource. Having said this, the volumes of freshwater used for fracking may only account for 0.3% of total freshwater use in the USA - the effects on local hydrology could be devastating if they are allowed to go unchecked.
The report is the main source of information used for this blog and introduction to water use in fracking. the Report is available here: (http://www.worldenergyoutlook.org/media/weowebsite/2012/goldenrules/weo2012_goldenrulesreport.pdf)
Image URL: (http://www.westernresourceadvocates.org/frackwater/FRACKINFOGRAPHIC_laura.jpg)
Sourcing the vast volumes of water required for hydraulic fracturing is a much debated environmental concern that still has no real resolution. At this moment in time, water plays an integral role in releasing the valuable natural gas from tight shale formations and therefore the sustainable sourcing of said water is of vital importance. Currently, water is taken from surface water supplies (rivers, lakes and streams), from local boreholes and aquifers or is transported via trucking.
The argument put forward by those advocating an anti-fracking campaign, is that none of these options are sustainable and ultimately may have serious implications for the local environment, including water table draw-down, biodiversity loss and other negative effects on the ecosystem, such as increased sediment run off.
The removal of fresh water from local rivers and streams may have disastrous consequences, currently fresh water ecosystems are among the most stressed in the world (http://vmpincel.bio.ou.edu/download/publications/VaughnB10.pdf). There have been numerous reports stating that the biodiversity of fresh water ecosystems have already been decimated by anthropogenic activity, particularly by the effects of eutrophication. Furthermore, there is global concern about increasing fresh water demands for an increasing population, with water scarcity affecting 40% of the world population (http://www.unwater.org/statistics_res.html). Seen as we already have a grasp of the fragility of fresh water ecosystems, is it morally right to source water in such a manner?
In the case of groundwater extraction from local aquifers, concerns have been voiced regarding the reduced availability of water for use by local communities and in other water intensive uses, such as agriculture. Further contention arises around the issue of over-extraction; which, if it occurs, can lead to falling water tables, higher pumping costs, empty wells and saline intrusion in coastal areas. (http://www.eea.europa.eu/themes/water/water-resources/impacts-due-to-over-abstraction)
The use of trucks to carry water to the fracking sites, also has many negatives associated with this practice. As stated in the Golden Rules for a Golden Age of Gas: World Energy Outlook, Special Report on Unconventional Gas, 2012, if a well were to require 1500 cubic meters of water, this would amount to 500 truck loads of water to be delivered ( this is done on the basis that the average truck can hold approximately 30 cubic meters of water). This is obviously a very energy intensive activity and may raise the carbon footprint of the whole operation. Furthermore, this can lead to high congestion rates on local roads and can exacerbate wear and tear of roadways and bridges.
Another concern is that annual water use for fracking is 100% consumptive. Around 4/5 of the injected water remains in the shale formation into which it was injected and the remaining 1/5 will return to the surface as contaminated flow-back water (which is usually treated and injected into deep wells). Whereas use of water in other industries, such as in the nuclear power industry, there can be treatment and discharge back into local waterways- thus mitigating effects of water consumption.
Water availability is already recognised as a serious constraint on localities of fracking developments. For example in the Xinjian Uyghur Autonomous Region, China are some of the largest economically viable shale gas deposits in the whole of the China, but also suffers from severe water scarcity. There are also many other prospective sites that remain, to date, utilised because there is already intense competition for water resources. This means that developments have been favoured in the Sichuan Basin, were there is abundant water, readily available. (http://www.scientificamerican.com/article.cfm?id=china-slow-to-start-fracking-for-natural-gas-in-shale)
Over the next few posts I will explore the wider issues surrounding extensive water use in the fracking process. These include:
- Potential consequences for the UK's future fracking prospects
- Studies of past effects on ecosystems
- The development of less-water intensive techniques and technological advances
- Recycling of flow-back water and improving the yield of flow back waters.
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