Arizona already boasts of an aggressive renewable energy system and has one of the country’s most stringent energy efficiency programs. Nevertheless, that didn’t stop the Obama administration from dropping a bombshell on the state.

After a decades-long struggle over the best way to confront dust pollution in metro Phoenix, the U.S. Environmental Protection Agency announced today that it has approved the state’s air quality plan for the Valley, officers from the Arizona Department of Environmental Quality confirmed.

The U.S. Environmental Protection Agency has issued a supplemental proposal to reduce emissions at the Navajo Generating Station, roughly a week after the federal agency extended the public comment period on plans to clean up the coal-burning power plant.

A group of Arizona business leaders say they have until Aug. 5 to tell the U.S. Environmental Protection Agency why forcing the Navajo Generating Station to spend as much as $1 billion on retrofits to the coal-powered plant would have dire consequences on the state economy and residents’ pocketbooks.

We are disappointed that the Sierra Club chose to misrepresent the facts in the current debate over regional haze controls at Apache Generating Station in southeastern Arizona.

The Arizona Corporation Commission is criticizing recent actions by the U.S. Environmental Protection agency to clean up the state's power plants.

Two environmental activist groups are seeking to intervene in the lawsuit that Arizona filed against the U.S. Environmental Protection Agency over regional haze.

Six school districts in Arizona have done compliance work to avoid hefty federal fines for asbestos violations.

The U.S. Environmental Protection Agency says it has exceeded its goals in assessing structures on the Navajo Nation for uranium contamination.

The federal government is proposing new limits for pollution from a coal-fired power plant on the Navajo Nation that it says will improve visibility at places like the Grand Canyon, but it could come with a price tag of more than $1 billion, according to the plant's owners.