Last week, EPA finally responded to the Sierra Club’s petition requesting that it eliminate exemptions and defenses for excess emissions resulting from startup, shutdown, or malfunction events. 
EPA concluded that it needed to issue a SIP call to 36 states requesting that they revise their SIPs to conform to EPA’s current understanding regarding how SSM events should be handled.
The SIP call will require affected states to eliminate three separate types of protection currently given to generators in connection with excess emissions during SSM events:
- Automatic exemptions
- “Director’s discretion” exemptions
- Affirmative defenses
To a significant extent, EPA’s hands were tied by the decision in NRDC v. EPA, which held in the NESHAP context that the CAA bars EPA from creating affirmative defenses to liability. Those states which previously incorporated such provisions in their SIPs will presumably still be sympathetic to at least some claims by generators that excess emissions during SSM events were unavoidable, and thus may exercise enforcement discretion. Therefore, the most significant impact of the SIP call will likely be an increase in citizen suits related to emissions during SSM events.
If you don’t want to wade through the entire 554 pages of EPA’s response to the petition to learn what EPA did with respect to states that matter to you, EPA’s 5-page fact sheet includes a table listing EPA’s final action for each affected state.