Ina Fassbender/Reuters
Wind turbines in Germany, with a coal power plant in the distance.
In a 5-4 ruling, the Court found that the Environmental Protection Agency did not appropriately consider the costs to utility companies when handing down the rule under the Clean Air Act.
"We hold that EPA interpreted unreasonably when it deemed cost irrelevant to the decision to regulate power plants," Justice Antonin Scalia wrote in the court's majority opinion.
The challenge centered on new EPA regulations that would prohibit some plants from emitting toxic chemicals, including mercury. But industry groups and more than 20 states sued the federal government, arguing that the EPA did not adequately consider the costs to power plants before instituting the regulations.
The Obama administration argued that the costs were only a fraction of the industry's profits. The EPA initially said it was not required to take costs into account, but that it eventually did so and determined that benefits far outweighed the costs.
The case is part of a series of legal challenges to the Obama administration's unilateral efforts to curb pollution from coal-burning power plants. With these regulations, the government attempted for the first time to employ the Clean Air Act to limit and carbon pollution from the nation's power plants.
"Most recently, what I've done is I've said - about 40 percent of the carbon that we emit comes from power plants. So what we've said is, through the Environmental Protection Agency, we're going to set standards. We set standards for the amount of mercury and arsenic and sulfur that's pumped out by factories and power plants into our air and our water," President Barack Obama said at a town-hall style event last June. "Right now we don't have a cap on the amount of carbon pollution. So we said we're going to cap it."
More to come...