What is fracking? Q&A - Telegraph Why is it called fracking? It is shorthand for hydraulic fracturing and refers to how the rock is fractured apart by the high pressure mixture. Experts also refer to a "frac job" and a "frac unit." Resources and reserves Later today the British Geological Survey will release a report, which is expected to say that there is far more shale gas resources that previously thought. It said there could be 1,300 trillion cubic feet at one site alone, but it is unclear how much could be extracted. And that is the important bit to note - resources is how much is under the ground, but reserves is how much can actually be extracted. Nobody actually knows how much gas can be extracted but it is generally thought to be between 10-30pc, but even that could meet British energy needs for years. Why bother? The natural gas, which is produced and trapped in rock formations following the breakdown of organic matter, is in such high demand it is known as "energy gold." It boosts overall worldwide gas supplies and can help to reduce market cost. It is believed that there is more than the entire gas reserves left in the UK North Sea and if it can be drilled it could power the UK for decades. It could also lead to cheaper energy bills for households. Prices have tumbled by half on the other side of the Atlantic, where the shale gas boom has transformed the US energy landscape. It's estimated to have offered gas security to the US and Canada for about 100 years, and has presented an opportunity to generate electricity at half the CO2 emissions of coal. What's the problem with Fracking? Fracking has been linked to a variety of environmental concerns including the contamination of groundwater supplies, air pollution and seismic activity, although there has so far been little consensus on any of these points. One major report earlier this year found that the risk of water sources being contaminated was no higher with fracking than other drilling processes, and that most pollution was due to mistakes made at ground level such as spillage of waste water. But another study recently claimed that emissions released into the atmosphere during the process could cause headaches and breathing problems in people living up to half a mile away. This week a study suggested that households within a kilometre of shale gas fracking wells could be at higher risk of having their drinking water contaminated by flammable gases. A study of 141 drinking water samples from bore holes in Pennsylvania found higher levels of methane, ethane and propane in those within a kilometre of shale gas fracking sites. The Blackpool earthquake was the first direct evidence of fracking causing seismic activity, but it has been argued that there is only a minimal risk of a tremor big enough to damage any buildings or people. What is the current situation in Britain? Most drilling projects are happening in the US, where the technique has been used for decades, and Britain is at a comparatively early stage of exploration. The controversial process was suspended in the UK in 2011 after fracking company Cuadrilla caused earth tremors near Blackpool. The fracking ban was lifted in December. Fracking company IGas has yet to frack any wells, having so far drilled one exploratory well at Ince Marshes, near Ellesmere Port in Cheshire, last year. Where is fracking happening? Britain has sizeable resources of shale gas underneath the Pennines, some of the home counties and parts of Wales, Scotland and Northern Ireland, meaning it could be a cheaper alternative to importing fossil fuels and can help to reduce market cost. Cuadrilla has identified a "vast reserve" on the Fylde coast in Lancashire, where tremors suspended drilling in 2011. The government has identified areas of high shale gas potential across the country. Other companies want to explore for shale gas in Fermanagh, the Vale of Glamorgan, Somerset, Kent and Sussex.