Supreme Court will review EPA first-ever limits on mercury emissions from power plants

The Supreme Court is stepping into a new case about Obama administration environmental rules, agreeing to review a ruling that upholds emission standards for mercury and other hazardous air pollutants from coal- and oil-fired power plants.

The justices on Tuesday said they would hear arguments from industry groups and states that are challenging Environmental Protection Agency rules designed to clean up chromium, arsenic, acid gases, nickel, cadmium as well as mercury and other dangerous toxins.

The federal appeals court in Washington, D.C., upheld the rules in April.

One judge on the appeals court complained then that the EPA didn't consider costs in deciding whether regulation of hazardous air pollutants from power plants is appropriate.