Hydro-fracturing
From Wikimarcellus
Hydro-fracturing, or fracing for short, is the process of injecting water, sand, diesel fuel, and/or a cocktail of chemicals into a well to fracture shale thereby releasing methane that is trapped in pores of the rock.
Many environmentalists have raised concerned about this process as a source of toxic contamination of the water supply. It also requires millions of gallons of water which usually must be trucked into drilling sites. The trucks and diesel engines used to power the drilling equipment are recognized as a sources of air pollution and have also led to concerns about noise-control issues.