The Sierra Club on June 13 celebrated the fact that on the same day the U.S. Supreme Court decided not act on a challenge related to the U.S. Environmental Protection Agency’s Mercury and Air Toxics Standards (MATS).
The high court refused the state of Michigan’s request to review the U.S. Court of Appeals for the D.C. Circuit’s decision to leave MATS in place while the EPA responded to the Supreme Court’s decision last year in Michigan v. EPA to create an additional assessment of MATS’ costs to industry. MATS requires coal- and oil-fired power plants to significantly reduce their emissions of toxic pollutants.
Last year, the Supreme Court required EPA to conduct an additional assessment of the protections’ costs to industry – which EPA has since declared to be relatively modest, especially in relation to the massive health benefits of the protections. Affected industries have separately challenged that new finding in a separate suit that is pending in the D.C. Circuit.
Challengers to MATS had asked the Supreme Court to decide whether the D.C. Circuit had erred in deciding to leave MATS in place, while EPA completed the costs assessment. EPA, supported by the Sierra Club and other public health and environmental groups, as well as several states and some electricity producers, pointed out in their responses that the agency had already completed the mandated cost assessment, rendering that question largely moot, and that virtually all power plants had already complied with MATS requirements.
The initial MATS compliance deadline was in April 2015, with a number of power plants getting one-year extensions to April 2016. Only a handful of plants have gotten a second one-year extension, to April 2017, which is an extension that EPA hands out sparingly based on grid reliability concerns if a particular plant has to be shut due to MATS.