Fracking is a technique used to release gas and oil from shale rock.
- It involves drilling down before fracturing layers of rock using a pressurised liquid.
- Water, sand and chemicals injected into the rock then allow gas to be released.
- The process enables petroleum, natural gas and other substances to be extracted.
More top news
Britain's Got Talent star Ryan Howell has died of bone cancer, aged just 18.
Community Furniture Aid in Bridgend says families have been left sleeping on hostel floors due to a lack of donations.
A 'bizarre' combination of poisonous metals was found in the body of a Cardiff woman allegedly murdered by her lover, a court has heard.