"FLAGSTAFF, Ariz. -- The U.S. Environmental Protection Agency has issued its final rule aimed at cleaning up the largest single source of haze-causing pollutants in the country."

"Rather than mandate that the Four Corners Power Plant take one avenue to reducing nitrogen oxide emissions, the EPA is giving the plant's operators a choice, regional administrator Jared Blumenfeld told The Associated Press on Wednesday. Arizona Public Service can either upgrade the five units at the northwestern New Mexico plant or go with its own plan to shut down three units and install pollution controls at the two others.

The actions would cut emissions that can worsen visibility at national parks like the Grand Canyon by 80 percent and 87 percent, respectively."

Felicia Fonseca reports for the Associated Press August 8, 2012. [2]