FILE - In this Sept. 4, 2011 file photo shows the main plant facility at the Navajo Generating Station, from Lake Powell, in Page, Ariz. Two environmental groups are asking a federal court to set a ... more 
FILE - In this Sept. 4, 2011 file photo shows the main plant facility at the Navajo Generating Station, from Lake Powell, in Page, Ariz. Two environmental groups are asking a federal court to set a deadline for the U.S. Environmental Protection Agency to issue mandates for pollution controls at two power plants, including Four Corners, on the Navajo Nation.(AP Photo/Ross D. Franklin, file) less 
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Associated Press | Photo By Ross D. Franklin, file
Thu, Mar 22, 2012 3:59 PM EDT