This not my subject, scientifically speaking, but I thought it worth a quick mention having read a recent paper on surface water contamination (Olmstead,et al. Proceedings of the National Academy of Sciences, 2013. 110(13): p. 4962-4967) and having noted the government’s recent tax break for shale gas development, I thought I should at least make a few comments.
Shale gas occurs as methane (natural) gas bubbles within pores in deposits of shale (produced by pressure and heat acting on deposits of organic material, but at pressures and temperatures too low to produce oil or coal) and is extracted by a process known as Fracking. As illustrated, this process involves a deep drill into and along a shale deposit and then the introduction of a water/chemical fluid that leads to fracturing of the shale and subsequent release of the trapped gas. In the USA the chemicals used are proprietary and their composition a secret, which lends an air of mystery to the dangers that involve this process.
The linked paper shows results that raise concerns about surface water contamination associated with both spillage (accidents) and the drilling process, but more importantly with off-site waste treatment and above ground land management. This aspect of the process would concern me in the light of recent flooding in this country and our overall inability to clearly manage surface water in a controlled manner. Unless the government begins to manage water, flooding and drainage better I foresee a new problem developing around any onshore shale drilling projects. It is always important to weigh the benefits to society of a new energy source against the environmental impact of the development of the energy source, but too often money and profit is the driving factor!
There needs to be a more open and informed approach to this type of energy development where the public can make a sensible judgement of the impact and have some say in the rate of development. Although the government has indicated that Fracking in this country will be less secretive and more regulated, but that does not address many concerns. There is no doubt that Fracking will be a major industry in Britain very soon and the political driver of securing gas reserves, that are not subject to external political whims, will be a major factor. Opposition to the process must be driven by concerns that are backed by good science, which is a major problem as there are insufficient scientific papers examining health concerns associated with the Fracking process, but organisations such as Greenpeace may well adopt a political agenda that will not work against the economic drivers for using this gas (a similar approach has delayed but cannot prevent the use of nuclear power and Greenpeace need to “see the bigger picture” of the need for energy that cannot be met by energy saving).
In conclusion, I think Fracking is a messy industry that will be coming to your area soon – shale deposits in the UK are widespread and numerous – it may lead to cheaper gas (although I doubt that), but it should make us, as a country, less dependent on external fuel supplies, but I am concerned that there will be spills and accidents that may have a long term environmental impact that we are as yet un aware of! One last interesting observation is that the burning of existing (known) fossil fuel supplies will already make us exceed existing limitation on carbon usage! So, the use of shale gas can only make worse the problems associated with the greenhouse gas carbon dioxide.