This March 25, 2014 file photo shows a machine mixing sand and water, left, before it is pumped underground during a hydraulic fracturing operation at an Encana Corp. well pad near Mead, Colo. The ... more 
This March 25, 2014 file photo shows a machine mixing sand and water, left, before it is pumped underground during a hydraulic fracturing operation at an Encana Corp. well pad near Mead, Colo. The energy boom is scrambling national politics. Democrats are split between environmentalists and business and labor groups. Some deeply-conservative areas are allying with conservationists against fracking, the technique largely responsible for the surge. (AP Photo/Brennan Linsley, File) less 
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Associated Press | Photo By Brennan Linsley, File
Sat, Apr 19, 2014 8:30 AM EDT