Hydraulic fracturing (fracking) is a technique used to extract hydrocarbons trapped in certain types of rock. In particular the widespread use of fracking is being driven by the expansion in shale gas extraction.
What is shale gas?
Shale gas is natural gas that is trapped in impermeable shale rock, as opposed to more conventional natural gas deposits that are trapped below a layer of impermeable rock. Therefore simply drilling down to it is not enough and the rock must also be fractured in order to allow the gas to escape.
How does hydraulic fracturing work?
Hydraulic fracturing uses pressurised fluid to free trapped gas. Wells are drilled and the fracking fluid injected into them under high pressure to crack the rock. The fracking fluid consists of water, sand and a massive amount of chemicals. Millions of gallons of water (and hundreds of tons of chemicals) are used to frack a well.
Why should we be concerned about fracking?
There is a substantial amount of evidence documenting the side effects of hydraulic fracturing, the majority of which are related to water contamination. The main causes of concern include:
- Methane contamination of ground water.
- The toxic chemicals (and their carcinogenic properties) used in the process.
- Contamination of water as a result of various materials leaching out of fracked rocks into the fracking fluid. Of particular concern are toxic elements like arsenic that can be brought to the surface by this process.
- Radioactive Contamination. Radioactive isotopes (such as radium-226) can also be leached out of rocks the fracking fluid passes through. Biological concentration of these materials up the food chain would be the largest concern.
- Food supply contamination via contaminated water.
- The quantity of water involved in the fracking process in a climate of drought, water resource pressures and the needs of the agricultural community in Dorset.
- Fracking has also been linked with air pollution, due to the production of ozone and leaks of a variety of volatile chemicals. Increases in respiratory problems have already been reported around the first fracking site in the UK.
- Fracking has also been associated with earthquakes, most notoriously in the UK in Lancashire.
- Fracking also demands an industrial landscape and an increase in traffic, the infrastructure of which has its own pollution consequences.
- Fracking also extinguishes any opportunities to reduce greenhouse gas emissions on a county or national level.
With thanks to FrackFreeSomerset