In 1977, acting under its discretion to regulate sources under Section 111, EPA determined that excess emissions of air pollutants during startup, shutdown, and malfunction (SSM) events did not constitute deviations from the underlying emissions standards, so long as the source exercised good air pollution control practice for minimizing emissions (called the “general duty” standard).
Two decades later, EPA adopted a similar SSM exemption to the “emissions standards” governed by Section 112 (generally referred to as the Maximum Achievable Control Technology or “MACT” standards) so long as the source developed and implemented an SSM plan, which would be incorporated by reference into the source’s Title V permit.
In Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. Dec. 19, 2008), the Sierra Club challenged EPA’s extension of the SSM exemption to Section 112’s “emission standards” for HAPs, arguing Section 112 of the Act required “continuous” emissions reduction.
The federal court agreed with Sierra Club and vacated the SSM exemption for Section 112 “emission standards.” The court’s decision turned on Congress’ mandate that “emission standards” for HAPs under Section 112 – in contrast to the emission limits for sources under Section 111 – required “continuous” limits on emissions.
How the removal of the SSM exemption under Section 112 plays out has yet to be decided. In a recently proposed MACT standard, EPA stated it was still evaluating the federal court’s December 2008 decision to decide whether to appeal but, at least for now, will not propose a new SSM exemption for HAPs.
The federal court has extended the time for EPA to appeal the above decision until April 3, 2009. The mandate vacating the SSM exemption for HAPs will not be made official until at least 7 days after the disposition of any timely petition for rehearing by EPA.
Posted on
Wednesday, March 4, 2009
by Ivan L. London