Clean Power Plan (CO2)

On Oct. 23, 2015, the U.S. Environmental Protection Agency (EPA) published a final Clean Power Plan (CPP) ruling in the Federal Register that mandates carbon dioxide (CO2) emission guidelines for existing fossil fuel-fired electric generating units (EGUs) under the Clean Air Act.

Using the same analytical framework as CPP, the EPA also issued a carbon rule affecting existing fossil fuel-fired EGUs located on tribal lands. NGS, located on the Navajo Nation, is regulated under this carbon rule for tribal sources.


On Feb. 9, 2016, the U.S. Supreme Court voted 5-4 to stay the implementation of CPP, following a grant request by 27 states to block the plan. On March 28, 2017, President Donald Trump signed the Executive Order on Energy Independence, which callsĀ for a review of the Clean Power Plan. For more information, visit the EPA's Clean Power Plan page.