The USA's domestic energy boom is increasing demands on water supplies already under pressure from drought and growing populations, a new report says.
The water-intensive process used to extract oil and gas from shale underground — known as hydraulic fracturing or fracking — has required almost 100 billion gallons of water to drill more than 39,000 oil and shale gas wells in the U.S. since 2011, says Ceres, a green investment group.
More than half of those wells — 55% — were in drought-stricken areas, and nearly half were in regions under high or extremely high water stress, such as Texas, the report says.
To be in extremely high water stress means more than 80% of the area's available surface and ground water is already allocated for city, agriculture or industrial use. High stress means 40% to 80% of the water is already allocated, Ceres says.
Shale development is also occurring rapidly in areas where groundwater is already being depleted by other uses, including agriculture and residential development.
Nationwide, more than 36% of the 39,000 wells drilled since 2011 were in areas already experiencing groundwater depletion, the study says.
Hydraulic fracturing pumps water and chemicals at high pressure to break the shale, allowing trapped oil or gas to flow to the surface.
While fracking consumes far less water than agriculture or residential uses, the impact can be huge on particular communities and is "exacerbating already existing water problems," says Monika Freyman, author of the Ceres study.