Regulatory Developments, Special Topics in Environmental Management

EPA Rolls Back Startup and Shutdown Excess Emissions Prohibition

On October 9, 2020, EPA Administrator Andrew Wheeler issued a memorandum to EPA regional administrators addressing “the question of whether and when it may be permissible for a state to include certain types of provisions governing periods of startup, shutdown, and malfunction (SSM) in state implementation plans (SIPs) developed pursuant to section 110 of the Clean Air Act [CAA].”

Air pollution, pollutants, smokestacks


In doing so, Wheeler’s memo replaces certain policy actions within the 2015 SSM SIP Action.


The CAA is based on “cooperative federalism,” which gives states “primary responsibility” for meeting National Ambient Air Quality Standards (NAAQS) while providing states with flexibility for the specific needs and priorities of each state. Each state is required to prepare and submit SIPs that identify “the controls and programs the state will use to attain and maintain the NAAQS.” The SIPs are submitted to the EPA for approval.

“CAA section 112 requires that once a source category is listed for regulation, EPA (not the states) must use a specific and exacting process to establish nationally applicable, category-wide, technology-based emissions standards,” according to the EPA. “With respect to attainment and maintenance of the NAAQS, the U.S. Supreme Court has recognized that the CAA gives a state ‘wide discretion’ to formulate its plan pursuant to CAA section 110 and went so far as to say that ‘the State has virtually absolute power in allocating emission limitations so long as the national standards are met.’”

On June 12, 2015, the EPA issued an SSM SIP policy, “a nonbinding policy statement that does not, in and of itself, constitute ‘final’ action.” Then, the EPA took final agency action to apply the policy by issuing findings that 36 states had SIP provisions that were inadequate to meet the national CAA standards.

“The 2015 action required various states to remove relevant SSM provisions from their SIPs and delete related affirmative defenses,” according to “A lawsuit was subsequently filed by 17 State Attorney Generals … challenging the EPA Startup, Shutdown, and Malfunction SIP call.”

Wheeler’s memo reviews case law addressing SIPS and previous EPA guidance and comments that “ … both those referred to as ‘automatic exemptions’ and those termed ‘director discretion provisions’ in the 2015 SSM SIP Action—may be permissible in SIPs under certain circumstances.”

Wheeler maintains that states are allowed great latitude in determining how to meet the NAAQS and that state-specific SSM exemptions are only allowed “… for limited periods applicable to discrete standards, only if the SIP is composed of numerous planning requirements that are collectively NAAQS-protective by design.”

Wheeler says the EPA will evaluate SIP provisions to determine if the “… requirements of a SIP are collectively NAAQS protective despite the inclusion of an SSM exemption provision….”

In conclusion, Wheeler wrote that the memo was intended as guidance and is nonbinding for “states, EPA, or other parties, but it does reflect EPA’s current understanding of the statutory requirements of the Clean Air Act.”

Environmental groups are expected to pursue litigation over the conclusions reached in this memo, according to

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