An appeals court has ruled against the state of Arizona in a case challenging emissions-control measures imposed by the Environmental Protection Agency in a bid to improve visibility at federal parks.
The decision released Monday marked the third time that the 9th Circuit Court of Appeals has rejected challenges made by the state and companies to the federal regulations.
The previous decisions concluded the EPA had acted within its authority when it disapproved of portions of an emission-reducing plan developed by the state. The latest ruling focused on technical challenges to the rules.
The case arose over a dispute between the state and EPA over Arizona's emissions-controlling plan, which was produced in 2011.
The EPA replaced elements of the state plan that federal officials deemed problematic.