For many years, a number of state air regulations, including certain MEDEP, NHDES, and RIDEM regulations, have contained exemptions and/or affirmative defenses for excess air emissions occurring during startup, shutdown and/or malfunction (SSM). Under recent EPA proposals, these provisions may be in jeopardy. However, not all SSM protection is necessarily lost - there are steps that regulated facilities may take to effectively preserve SSM exemptions in certain circumstances.
EPA’s February 22, 2013 Proposal. On February 22, 2013 (78 Fed. Reg. 12459), EPA proposed to take action on a petition for rulemaking filed by the Sierra Club. That petition included three interrelated requests concerning exemptions in State Implementation Plans (SIPs) for excess emissions during periods of SSM. In response, EPA proposed to change its historic position on SSM exemptions such that SIPs in 36 states would now be deficient because they provide an automatic exemption for excess emissions during SSM. Even SIP provisions that provide the permitting authority discretion to exempt SSM excess emissions on a case-by-case basis would be disallowed under EPA’s proposal. However, EPA’s proposal would allow SIPs to authorize affirmative defenses for excess emissions due to malfunctions.
EPA identified the following as no longer meeting Clean Air Act requirements under its proposed revised interpretation in Region I:
- Maine – Chapter 101 (Visible Emissions – 4 hour startup/shutdown exemption)
- New Hampshire – NH Code R. Env-A 902.03 and 902.04 (General SSM Exemptions)
- Rhode Island – RI Gen. Laws § 23-23-15 (Operate During SSM)
EPA’s preamble notes that 40 C.F.R. Part 70 specifically allows Part 70/Title V permits to include emergency provisions where a source can assert an affirmative defense to enforcement by providing evidence that an excess emission was:
- Caused by an emergency (i.e., unavoidable malfunction);
- The permitted facility was being properly operated at the time;
- The permittee took all reasonable steps to minimize emissions; and
- The permittee submitted notice to the permitting authority within two working days.
EPA noted the apparent inconsistency between its proposal regarding SSM exemptions in SIPs and the emergency provision in Part 70, but did not propose to revise those provisions. Thus, under the February 22, 2013 proposal, the affirmative defense for excess emissions during malfunctions appears to remain viable, at least for Title V sources.
September 17, 2014 Supplemental Proposal. On September 17, 2014, EPA proposed to revise its February 22, 2013 rulemaking to invalidate any SIP provisions that provide an affirmative defense for excess emissions due to malfunctions – a reversal of its 2013 proposal. EPA did not identify any SIP provisions in Region I that run afoul of this newly proposed prohibition. However, in the course of this supplemental rulemaking, EPA reiterated its belief that SIPs may not contain automatic exemptions for excess emissions occurring as a result of SSM.
What Can You Do? In light of these actions by EPA, it appears that exemptions from SIP standards during SSM events may soon be unavailable. However, EPA did appear to leave two avenues available to address these events. Facilities should consider whether either or both options are available and may be incorporated into their permits:
First, EPA appears to believe that a SIP or permit may continue to provide an alternative emission or operating standard during startups and shutdowns provided the alternative is:
- Limited to specific, narrowly-defined, source categories using specific control strategies;
- Use of a control strategy for the source category must be technically infeasible during startup or shutdown periods;
- Frequency and duration of operation startup or shutdown mode must be minimized to the maximum extent practicable;
- Potential worst-case emissions could occur during startup and shutdown must be analyzed;
- All possible steps must be taken to minimize the impact of emissions during startup and shutdown on ambient air quality;
- The facility must be operated in a manner consistent with good practice for minimizing emissions; and
- Actions during startup and shutdown periods must be documented.
Second, EPA specifically noted that its proposals are not intended to address the “emergency” provision set forth in Part 70, which provides that the permitting authority may exempt excess emissions from a Title V/Part 70 source due to control equipment malfunction. (Note that this provision does not appear to apply to startups or shutdowns.) Thus, it appears this exemption may still be available to Title V sources.