Supreme Court Rules Against EPA MATS Regulations

The Supreme Court on Monday ruled against an Environmental Protection Agency regulation limiting mercury and other toxic emissions from power plants.

The Mercury and Air Toxics Standards rule remains in effect, however, until the D.C. Circuit Court determines how to apply the Supreme Court’s ruling.

Nearly all coal-fired power plants on the PJM system either already are or will be in compliance with the MATS rule or have retired. In addition to state and federal environmental regulations, coal-fired power plant operators face economic challenges from other competitive power sources and low growth in electricity use.

“The PJM wholesale markets have proven their ability and flexibility to adapt to changing regulations and needs in order to maintain adequate power supplies,” said Terry Boston, PJM CEO and president.

The EPA finalized rules limiting the release of mercury, heavy metals and acid gases from power plants in December 2011. Newer power plants use technology to curb hazardous releases; the EPA rule targets plants that still do not capture those emissions.

In the 5-4 decision, Chief Justice John Roberts and Justices Clarence Thomas, Samuel Alito, Antonin Scalia (who wrote the opinion) and Anthony Kennedy voted to overturn the rule, while Justices Elena Kagan, Sonia Sotomayor, Stephen Breyer and Ruth Bader Ginsburg sided with the EPA.

Since the ruling concerns just the cost-benefit analysis, the EPA can re-write the regulation.