flowback

noun

flow·back ˈflō-ˌbak

: liquid used in fracking that returns to the surface after being injected into shale

The drillers then shoot millions of gallons of highly pressurized water, mixed with sand and small amounts of additives known as fracking chemicals, down the well, widening the shale fractures. Natural pressure forces the liquids back up the well, producing what's known as flowback, and the gas rushes from the fractures into the pipe.—

Bryan Walsh

Methane within the shale diffuses into these fissures and flows up the well. Along with the gas comes flowback water, which contains fracking fluid and additional water found naturally in the rock.—

Rachel Ehrenberg