Ceres, a green investment group, says that hydraulic fracturing is straining water supply levels, especially in areas already suffering from drought.
Hydraulic fracturing, or fracking, requires a lot of water, reports USA Today. In three years, the U.S. has used nearly 100 billion gallons of water to tap into 39,000 oil and shale gas wells. The process used water and other chemicals shot at high pressure into the ground where oil or gas is known to be located.
Over half of the wells were drilled are in areas already suffering from water issues because of drought or increasing populations, with California and Texas hurting the most. These areas are considered to have extremely high water stress, which is a term that means 80 percent of available surface water already being allocated.
According to The Independent, in Texas, many of the wells each needed 4.5 million gallons of water.
President of Ceres green investors' network Mindy Lubber said, "Hydraulic fracturing is increasing competitive pressures for water in some of the country's most water-stressed and drought-ridden regions."
Exxon spoke with the Financial Times and noted that its shale oil and gas subsidiary, XTO, is careful about water usage, as it "works with local authorities to ensure there is adequate supply."