Johannesburg – Anyone who wants to attempt fracking in South Africa will now have to get permission from the water affairs minister.Fracking, or hydraulic fracturing, was added to the list of controlled activities in the National Water Act, according to a notice Water Affairs Minister Nomvula Mokonyane published in Friday’s Government Gazette.It was described as, "The exploration and or production of onshore naturally occurring hydrocarbons that requires stimulation, including but not limited to hydraulic fracturing and or underground gasification, to extract, and any activity incidental thereto that may impact detrimentally on the water resource."Fracking involves pumping a mixture of sand, chemicals, and water at high pressure into the ground, to free natural gas trapped between layers of shale, a type of sedimentary rock.According to the Treasure Karoo Action Group it had been shown to cause pollution of underground water sources, and used large volumes of water."We’ve known since May 2012 that the minister was considering declaring it a controlled activity," the group's operations director, Jeanie le Roux said."It's a positive development as it gives the department another level of control. People now need to get special authorisation from the department," she said.In May the environmental affairs department announced the start of a strategic environmental assessment on shale gas. It would look at the risks and opportunities associated with shale gas exploration.