Fracking  -  short for hydraulic fracturing, is a gas well extraction technique that fractures shale rock layers using a pressurized liquid. This process injects high pressure ‘fracking fluid’ (a mixture of water and hazardous chemicals) into a wellbore to create cracks in the deep-rock formations that allow the release of natural gas or petroleum. Each well takes about 1 – 3 million gallons of fracking fluid. After the fracking process is completed, the well returns about 1/3 of the fluid immediately as flowback water, a briny mixture of water, fracking fluid and minerals dissolved from the shale. The well also returns about 500 barrels of producer fluid, a supersaturated mixture of water, fracking fluid and dissolved minerals from the well.