Hydraulic fracturing, or fracking, is increasing competitive pressures for water in some of the most water-stressed and drought-ridden U.S. regions, a study indicated. Fracking involves massive amounts of water, sand and chemicals injected at high pressure to fracture rock and release stored gas. The technique has unleashed a U.S. oil and gas boom. The study by Ceres — an investor group based in Boston that focuses on sustainability issues — is based on water use data from 39,294 oil and gas wells reported to FracFocus.org from January 2011 through May 2013 and water stress indicator maps developed by the World Resources Institute. More than 55 percent of the wells were in areas experiencing drought and more than 36 percent overlay regions experiencing groundwater depletion, Ceres said in a news release Wednesday announcing its “Hydraulic Fracturing and Water Stress: Water Demand by the Numbers” report. […]