Emissions During Periods of Startup, Shutdown, & Malfunction (SSM)
On May 22, 2015, EPA issued a final rule to ensure states have plans in place that require sources across the country to follow air pollution rules during times when the facility is starting up or shutting down, or when a malfunction occurs (or "SSM").
Air pollution emitted during these periods may adversely impact the health of people nearby and contribute to smog and other problems in communities that are further downwind.
- Final Rule: State Implementation Plans: Response to Petition for Rulemaking; Restatement and Update of EPA’s SSM Policy Applicable to SIPs; Findings of Substantial Inadequacy; and SIP Calls to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown and Malfunction (PDF)(147 pp, 928 K, About PDF)
- Sierra Club's Petition (June 2011)
- Legal Background Memorandum (February 4, 2013)
- Federal Register Proposed Rule (PDF)(82 pp, 675 K) (February 22, 2013)
- Supplemental Proposal (PDF)(38 pp, 464 K) (September 5, 2014)
Recent Regional Updates
- On May 20, 2019, the Acting Administrator of the EPA Region 4 Office signed a proposal to approve a State Implementation Plan revision submitted by the state of North Carolina for a SIP-approved rule regarding nitrogen oxides (NOx) emissions from large internal combustion engine sources and to withdraw the SSM SIP Call for North Carolina that was issued during the 2015 SSM SIP Action.
- On April 23, 2019, the Acting Administrator of the EPA Region 6 Office signed a proposal to withdraw the finding of substantial inadequacy for the Texas State Implementation Plan and to withdraw the SSM SIP Call for Texas that was issued during the 2015 SSM SIP Action.
- On March 15, 2017, Texas submitted a petition for reconsideration of the final rule and requested an administrative stay of the action, with respect to the Texas State Implementation Plan (SIP). On October 16, 2018, EPA notified Texas that EPA had partially granted the petition and would use its discretion to reconsider the Texas SIP Call that was included in the 2015 SSM SIP Action.
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