The Dangerous Consequences of the Supreme Court's Ruling on Mercury Pollution

The U.S. Supreme Court fanned away one of the Obama administration’s toughest regulations on air pollution Monday morning. By rejecting the U.S. Environmental Protection Agency’s Mercury Air Toxics Standards (MATS) rule SCOTUS has stripped away a vital tool with significant implications for environmental and public-health protections for cities. The EPA’s MATS regulations focus on coal- and oil-burning power plants, requiring them to modify the design of their facilities so that they emit less harmful air pollutants.

Five justices from the court’s conservative wing agreed that the EPA considered the costs of such design modifications too late in its process of finalizing the new mercury standards. On Monday, SCOTUS ordered the case back to the D.C. Circuit Court, which had already upheld the EPA’s MATS rule back in April 2014. Reading for the majority, Justice Antonin Scalia said Monday: "EPA must consider cost—including cost of compliance—before deciding whether regulation is appropriate and necessary. It will be up to the Agency to decide (as always, within the limits of reasonable interpretation) how to account for cost."