The state and four utility companies had asked the 9th Circuit U.S. Court of Appeals for the delay while the court reviews the U.S. Environmental Protection Agency’s rule.
The court denied the request in a brief order this week.
The EPA partially approved Arizona’s air quality plan for the Cholla, Coronado and Apache generating stations. But the agency says the state didn’t do enough to control nitrogen oxide emissions. The plants’ operators have five years to comply with set limits.
State Department of Environmental Quality Director Henry Darwin has said Arizona should be making decisions about what’s in the best interest of the state, not the EPA.