A worker helps monitor water pumping pressure and temperature at an Encana Oil & Gas (USA) hydraulic fracturing and extraction site outside Rifle in western Colorado on March 29, 2013.
A worker helps monitor water pumping pressure and temperature at an Encana Oil & Gas (USA) hydraulic fracturing and extraction site outside Rifle in western Colorado on March 29, 2013. Brennan Linsley Associated Press
A worker helps monitor water pumping pressure and temperature at an Encana Oil & Gas (USA) hydraulic fracturing and extraction site outside Rifle in western Colorado on March 29, 2013. Brennan Linsley Associated Press