Fracking involves the injection of water containing a surfactant and various other chemicals under high pressure into a source rock e.g. shale, causing the latter to fracture and release natural gas (principally methane).
For more than six decades, gas companies have been using advanced technologies to hydraulically fracture and safely procure natural gas from up to two miles beneath the surface of the earth.
In this process, after a well is drilled, pressurized water is injected into the well to fracture the shale and open fissures that enable natural gas to flow more freely out of the well.