More Bad News for Coal: U.S. Supreme Court Won't Block Mercury Emissions Rule

"The Supreme Court on Monday left intact a key Obama administration environmental regulation, refusing to hear an appeal from 20 states seeking to block rules that limit the emissions of mercury and other toxic pollutants from the nation’s power plants," writes Brady Dennis, environmental reporter for The Washington Post.

The high court’s decision leaves in place a lower-court ruling that found that the regulations, put in place several years ago by the Environmental Protection Agency, could remain in effect while the agency revised the way it had calculated the potential industry compliance costs. The EPA finalized its updated cost analysis in April.

"The EPA estimates that MATS will prevent up to 11,000 premature deaths and more than 100,000 asthma and heart attacks each year," notes the Sierra Club's press release on the Supreme Court's rejection of the appeal. It also provides an excellent review of the court case, which is helpful because following the trail of federal court rulings on the EPA's Mercury and Air Toxic Standards (MATS) rule is not so easy.

Almost a year ago, Planetizen managing editor James Brasuell posted that the Supreme Court "ruled 5-4 against regulations by the Environmental Protection Agency to limit emissions of mercury and other air pollutants." However, it also "allowed the rule to stay in effect and returned it to the U.S. Court of Appeals for the District of Columbia Circuit to decide how the cost-benefit analysis should be conducted," wrote Sarah Tincher, energy reporter for WOWK-TV in West Virginia on December 18, 2015.

The Dec. 15 ruling by a three-judge federal appeals court panel "upheld the higher court’s decision, requiring power plants to continue to comply with the MATS standard while EPA continues to work on considering costs," adds Tincher.

"In March... Chief Justice John G. Roberts Jr. rejected a request to stay the Mercury and Air Toxic Standards rule," writes Dennis for The Post. "More than 20 states had joined a lawsuit opposing the MATS rule, arguing that the controversial pollution controls mandated by the regulation are too expensive relative to the health benefits."

In April, the EPA issued an updated analysis of the estimated costs and benefits of the regulations, arguing that the cost for the industry to comply would amount to a fraction of annual revenue and probably would not lead to steep increases in customer bills. As the fight over the MATS rule has worked its way through the courts in recent years, many utilities have already complied with the new requirements.

And that brings us to Monday's decision by the Supreme Court to reject the appeal from the 20 states.

"According to the EPA, the rule applies to about 1,400 electricity-generating units at 600 power plants," writes Lawrence Hurley, Supreme Court correspondent for Reuters.

The mercury rules are separate from Obama administration regulations intended to curb carbon dioxide emissions that the Supreme Court put on hold on Feb. 9 in a legal challenge brought by 27 states and others. [See more posts on Clean Power Plan Rule.]

One final note to acknowledge Vox's David Roberts, who opined last year that Supreme Court's June 29 ruling "is probably not going to change the mercury regulations."