Emissions During Periods of Startup, Shutdown, & Malfunction (SSM)

Excess Emissions During Periods of Startup, Shutdown, and Malfunction; Partial Withdrawals of Findings of Failure To Submit State Implementation Plan:  Withdrawal of Direct Final Rule

January 7, 2025 - EPA is withdrawing the November 26, 2024, direct final rule (89 FR 93187) to partially withdraw two final actions finding that 13 States and/or local air pollution control agencies failed to submit required State Implementation Plan (SIP) revisions in a timely manner.  These SIP submissions were required to address EPA’s 2015 findings of substantial inadequacy and ‘‘SIP calls’’ for provisions applying to excess emissions during periods of startup, shutdown, and malfunction (SSM). On November 26, 2024, EPA also issued a parallel proposal which stated that if any relevant adverse comments were received during the public comment period, the direct final rule would need to be withdrawn before its effective date of January 10, 2025. The state of West Virginia submitted an adverse comment on EPA’s proposal; therefore, EPA is withdrawing the direct final rule and will address all comments received in any subsequent final rule. The comment period for the proposal closed on December 26, 2024.  EPA will not institute an additional comment period on any subsequent final rule.

Notice Withdrawing Direct Final Rule (pdf) (188.33 KB)

Startup, Shutdown and Malfunction (SSM)  Policy Implementation Following the Environ. Comm. Fl. Elec. Power v. EPA Decision

December 20, 2024 - EPA has issued a memorandum to clarify how the Agency intends to evaluate state implementation plan (SIP) submittals following the March 1, 2024, decision from the United States Court of Appeals for the District of Columbia in Environ. Comm. Fl. Elec. Power v. EPA, 94 F.4th 77 (D.C. Cir. 2024) (2024 SSM Decision). This memorandum establishes that EPA expects states to identify in their SIP submittals whether it is “necessary or appropriate” for the provisions being proposed for inclusion into the SIP are intended to be emissions limitations. EPA intends to operate under a rebuttable presumption that SIP provisions are intended to be emissions limitations. Further, EPA intends to review an air agency’s determination of whether it is “necessary or appropriate” for a provision it submits for EPA’s evaluation and approval into the SIP to be an “emissions limitation” in order to meet Clean Air Act requirements. 

Startup, Shutdown and Malfunction (SSM)  Policy Implementation Following the Environ. Comm. Fl. Elec. Power v. EPA Decision (pdf) (280.37 KB)

Partial Withdrawals of Findings of Failure to Submit State Implementation Plan Revisions to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown, and Malfunction

November 15, 2024 - In response to the D.C. Circuit’s decision in Environ. Comm. Fl. Elec. Power v. EPA, 94 F.4th 77 (D.C. Cir. 2024), EPA is partially withdrawing two final actions finding that several states and/or local air pollution control agencies failed to submit State Implementation Plan (SIP) revisions. These plans were required to ensure that all modes of source operation, including periods of startup, shutdown, and malfunction (SSM) have emissions limitations in place that can be appropriately enforced in all communities and populations across the affected states. The six state and/or local air agencies affected by this final withdrawal are: Alabama, District of Columbia, Ohio, Rhode Island, South Dakota, and West Virginia.

Once final, this action ends certain Clean Air Act (CAA) deadlines for EPA to impose sanctions and to promulgate a Federal Implementation Plan. EPA is withdrawing only the findings that apply to the provisions vacated by the D.C. Circuit Court. Because the D.C. Circuit vacated only certain portions of EPA’s findings of failure to submit, other provisions of that action still apply to some air agencies and CAA deadlines remain in effect as previously established.

The Agency is electing to also issue a parallel proposed action. EPA will accept comment on the parallel proposal for 30 days after publication in the Federal Register. If no significant adverse comment is received, the direct final action will become effective 45 days after publication in the Federal Register.

Direct Final Action:  Partial Withdrawals of Findings of Failure to Submit State Implementation Plan Revisions to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown, and Malfunction

Parallel Proposal:  Partial Withdrawals of Findings of Failure to Submit State Implementation Plan Revisions to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown, and Malfunction

Please note:  The address for EPA's Region 3 Office is incorrectly listed in the actions linked above.  The correct address is: 

4 Penn Center

1600 JFK Boulevard       

Philadelphia, PA 19103

Fact Sheet: Partial Withdrawals of Findings of Failure to Submit State Implementation Plan Revisions to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown, and Malfunction (pdf) (222.75 KB)

Findings of Substantial Inadequacy and SIP Calls to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown, and Malfunction

February 15, 2023 - EPA proposed actions regarding state implementation plans or SIPs addressing air emissions during periods of startup, shutdown, and malfunction (SSM) in eight states. These plans must be reviewed by EPA to assure they comply with the Clean Air Act (CAA) and are consistent with the Agency’s SSM Policy as outlined in the 2015 SSM SIP Action. EPA is proposing to reinstate its findings of substantial inadequacy (“SIP calls”) that were withdrawn in 2020 for the states of Texas, North Carolina, and Iowa for SSM provisions in those states’ SIPs that do not comply with statutory requirements and EPA’s SSM Policy. For additional SSM provisions identified as deficient by EPA, the Agency is also proposing to issue new findings of substantial inadequacy and SIP calls to:

  • the state of Connecticut;

  • the state of Maine;

  • Shelby County, Tennessee;

  • the state of North Carolina;

  • Buncombe County, North Carolina;

  • Mecklenburg County, North Carolina;

  • the state of Wisconsin; and 

  • the state of Louisiana.

EPA will accept comment on this proposed action for 60 days after it is published in the Federal Register. 

Proposed Acton: State Implementation Plans: Findings of Substantial Inadequacy and SIP Calls to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown, and Malfunction (pdf) (573.14 KB)

Fact Sheet: State Implementation Plans: Findings of Substantial Inadequacy and SIP Calls to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown, and Malfunction (pdf) (187.89 KB)

Finding of Failure to Submit State Implementation Plan Revisions to Amend Provisions Applying to Excess Emission During Periods of Startup, Shutdown and Malfunction

January 4, 2022 - EPA is determining that 12 state or local air pollution control districts failed to submit State Implementation Plan (SIP) revisions in a timely manner to address EPA’s 2015 findings of substantial inadequacy for provisions applying to excess emissions during periods of startup, shutdown, and malfunction (SSM). These areas include: Rhode Island, the District of Columbia, Alabama, North Carolina – Forsyth, Tennessee – Shelby (Memphis), Illinois, Ohio, Arkansas, South Dakota, California – San Joaquin Valley Air Pollution Control District, Washington – Energy Facility Site Evaluation Council, and Washington – Southwest Clean Air Agency.

The findings establish a 24-month deadline for EPA to either approve SIPs or finalize Federal Implementation Plans addressing SSM provisions.  The findings also establish timelines for the implementation of two mandatory sanctions that will take effect if these areas do not submit complete SIPs to address the SSM provisions, as required by the Clean Air Act.  

Fact Sheet: Findings of Failure to Submit State Implementation Plan Revisions to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown and Malfunction (pdf) (183.32 KB)

Final Action: Findings of Failure to Submit State Implementation Plan Revisions to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown and Malfunction (pdf) (269.23 KB)

Guidance Memorandum: Withdrawal of the October 9, 2020, Memorandum Addressing Startup, Shutdown, and Malfunctions in State Implementation Plans and Implementation of the Prior Policy

September 30, 2021 - EPA is returning to its 2015 policy explaining that State Implementation Plan provisions that provide exemptions from air emissions limits during periods of startup, shutdown and malfunction (SSM) or that provide affirmative defense provisions are not consistent with the Clean Air Act and would not generally be approvable.  The reinstated 2015 Policy will ensure that all modes of source operation, including periods of SSM, have emissions limitations in place that can be appropriately enforced in all communities and populations across the affected states, including minority, low-income and indigenous populations overburdened by pollution. 

In addition, EPA plans to revisit the three related state-specific SIP actions that were finalized in 2020 that withdrew the SIP calls previously issued to Texas, North Carolina, and Iowa. Through notice-and-comment rulemaking actions EPA plans to reconsider whether any of the findings underlying those actions should be retained in light of the Agency’s change in policy.

Guidance Memo: Withdrawal of the October 9, 2020 Memorandum Addressing Startup, Shutdown, and Malfunctions in State Implementation Plans and Implementation of the Prior Policy (pdf) (4.24 MB)

October 9, 2020 Memorandum:  Inclusion of Provisions Governing Periods of Startup, Shutdown, and Malfunctions in State Implementation Plans (pdf) (825.27 KB)  – EPA has withdrawn this memorandum.

Regional Updates

Iowa

On October 23, 2020, the Administrator of the EPA Region 7 Office signed a final rule to approve a State Implementation Plan revision submitted by the state of Iowa for the 2010 SO2 Muscatine, Iowa nonattainment area and to withdraw the SSM SIP Call for Iowa that was issued as part of the 2015 SSM SIP Action.

On June 16, 2020, the Administrator of the EPA Region 7 Office signed a supplemental proposed rule to approve a State Implementation Plan revision submitted by the state of Iowa for the 2010 SO2 Muscatine, Iowa nonattainment area and to withdraw the SSM SIP Call for Iowa that was issued as part of the 2015 SSM SIP Action.

North Carolina

Texas

National Rule

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").

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 KB)

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Last updated on April 17, 2025