On August 5, 2016, the Environmental Protection Agency (EPA) denied two petitions by environmental and industry groups to reconsider startup and shutdown issues under the Mercury and Air Toxics Standards (MATS) rule and the Utility New Source Performance Standards (NSPS).

These regulations, finalized in February 2012, impose operational requirements to minimize emissions during periods of start-up and shutdown in lieu of numeric limits. The environmental groups argued that numeric limits should apply during these periods and they did not have the opportunity to adequately comment on this issue. EPA denied the environmental groups’ petition arguing the groups had adequate opportunity to submit comments during earlier rulemaking proceedings.

As we have previously reported, EPA’s MATS rule is the subject of ongoing litigation. EPA’s treatment of startup, shutdown, and malfunction (SSM) periods within state implementation plans is also the subject of developments and an ongoing legal challenge.