power plant regulations

                In Michigan v. EPA the Supreme Court held 5-4 that the Environmental Protection Agency (EPA) acted unreasonably in failing to consider cost when deciding whether regulating mercury emissions from power plants is “appropriate and necessary.” Twenty-three states challenged the regulations.

                The Clean Air Act requires the EPA to regulate air pollution from stationary sources based on how much pollution the source emits. But EPA may only regulate emissions from fossil-fuel-fired power plants if it finds that regulation is “appropriate and necessary.” EPA found it “appropriate” to regulate mercury emissions because they pose a risk to human health and the environment and controls are available to reduce them. EPA found it “necessary” to regulate mercury emissions because other requirements in the Act did not eliminate these risks.