An update on fracking, 2014. link

Fracking or hydraulic fracturing is a mining process that releases small amounts of oil from tar sands. The process uses large amounts of water which is injected deep underground as high pressure steam. The steam dissolves the oil in the tar sands and it is brought to the surface by the fracking fluid which also contains solvents. The water that is used becomes contaminated by the solvents and by other toxic chemicals which are brought up by the process in addition to the small amount of oil that is recovered. [link]