As per EPA proposal, the plant operators will be required to install stringent pollution control technology at the facility to cut emissions of NOx from approximately 45,000 tons per year to 9,000 tons per year and reduce the visibility impact by an average of 57% in the surrounding area.

The plant operators can install and operate Selective Catalytic Reduction (SCR) technology on all five units at the plant to achieve its target of emission reduction and improved visibility, increasing the electricity bill for average Arizona Public Service residential customer by about 70 cents per week.

EPA will continue to consult with the Navajo Nation and other affected tribes, and the Federal Land Managers before finalizing the proposal, following which the Four Corners Power Plant will have five years to add the controls.

EPA regional administrator of Pacific Southwest region Jared Blumenfeld said that the Four Corners Power Plant is the largest source of nitrogen oxides in the nation and adding new pollution controls at this 45-year old plant will reduce these emissions by 80%.