Meet the author

Mark H. Allison


Little Rock, AR


WLJ partner Mark Allison authored this article for the March/April issue of Arkansas Environmental Federation (AEF) newsletter.

On March 1, 2024, almost two years after the case was argued, the D. C. Circuit Court of Appeals issued its long-awaited decision on EPA’s 2015 SSM SIP Call in Environmental Committee of the Florida Electric Power Coordinating Group v. EPA.1 

The 2015 SSM SIP Call determined that two provisions of the Arkansas State Implementation Plan (SIP) that excused emission exceedances during periods of startup, shutdown and malfunction (along with similar provisions in 36 other SIPs) conflicted with the Clean Air Act and should be removed or changed. Various parties, including the State of Arkansas, petitioned for review of EPA’s SIP Call. 

In a 2-1 decision, the Court rejected the arguments that these parties made for challenging the SIP call. Instead, the majority fashioned its own rationale and held that EPA did not make the necessary findings to properly call the SIPs. The Court vacated the SIP Call as to many of the SSM provisions involved, including Arkansas Rule 19.602. 

The Court analyzed four types of SSM provisions – (a) automatic exemptions, (b) discretionary exemptions based on agency action, (c) “overbroad” enforcement discretion, and (d) affirmative defenses. EPA had long ago approved many of these SSM provisions into the various state SIPs, which made them applicable in EPA enforcement actions and CAA citizens suits. 

The Court explained that the standard for EPA’s original approval of SIPs was less stringent than the standard for EPA to later call for an approved SIP to be revised. The Court remarked that “EPA cannot call states’ already-approved SIPs for slight or immaterial noncompliance with the Act. 

The 2015 SIP Call was based on EPA’s assumption that the SSM provisions in these SIPs were “emission limitations.” In other words, because the SSM provisions were in approved SIPs, they must be “emission limitations.” The CAA defines emission limitation as a measure “which limits that quantity, rate, or concentration of emissions of air pollutants on a continuous basis.” The Court explained, however, that “emission limitations” are not the only things in SIPs – SIPs also include “other control measures, means and techniques.” 

Therefore, just because a provision is in an approved SIP does not automatically make it an “emission limitation.” And, an emission restriction is not an “emission limitation” unless the restriction limits emissions “on a continuous basis.” 

Thus, a SIP provision that limits the quantity, rate or concentration of emissions on a noncontinuous basis is a “control measure” – not an “emission limitation. 

Furthermore, the CAA does not require that a SIP contain any “emission limitations.” A SIP must include an “emission limitation” only when it is “necessary and appropriate” to meet CAA applicable requirements. 

Therefore, the Court reasoned, under the standard for a SIP Call, the EPA would have to find that it was “necessary and appropriate” to enable a State to “meet the NAAQS or some other applicable requirement” that emission restrictions subject to the SSM provision “satisfy the statutory definition of an ‘emission limitation’.” Because EPA did not make such a finding in its SIP Call, it did not properly call the state SIPs, including the Arkansas SIP. 

The Court applied this reasoning to both automatic exemptions, which take effect immediately, and discretionary exemptions, which become effective on a decision by the state agency, noting that these provisions exempt compliance with the applicable emission restriction limit itself during SSM periods. This was a proper exercise of “States’ discretion . . . to determine what ‘enforceable emission limitations and other control measures . . . are necessary or appropriate to meet CAA requirements.” 

As to enforcement discretion provisions, i.e., a decision not to pursue enforcement for violation during an SSM period, the Court summarily held that EPA could call such a provision, to the extent it interfered with EPA’s enforcement rights or enforcement by citizens suits. The Court noted that the Tennessee SIP was the only SIP that EPA called for this reason. 

Finally, the Court addressed affirmative defense SSM provisions. It distinguished between complete affirmative defenses, examining Arkansas PC&E Rule 19.602 as an example, and partial affirmative defenses such as Arizona’s SSM provision, that only granted a defense to certain types of judicial relief, for example damages or penalties. 

The Court explained that complete affirmative defenses “create an exemption from the normal emission rule” and are functionally the same as automatic exemptions. Thus, complete affirmative defense SIP provisions were not properly called by EPA. As to partial affirmative defenses, the Court explained that because those defenses go to the relief available in an enforcement proceeding, they improperly interfere with the CAA’s enforcement mechanism and were improper. 

How does this decision affect the Arkansas SIP? Prior to the 2015 SSM SIP Call, the Arkansas approved SIP had three SSM provisions; 19.601 (Upset Conditions); 19.602 (Emergency Conditions), and 19.1004(H)(malfunctions, breakdowns and upsets for VOC control in Pulaski County). Rule 19.601 gives the DEQ Director the discretion to forego enforcement for certain upset conditions. This provision was not included in Sierra Club’s original petition to EPA and the resulting 2015 SSM SIP Call. 

Rule 19.602 provides a complete affirmative defense for certain emission exceedances that occur as the result of an emergency. As the Court pointed out, EPA did not make proper findings to call the Arkansas SIP on account of Rule 19.602 and presumably Rule 19.602 would still be effective in the EPA approved SIP; however, in November 2022, while the Florida Electric case was still pending, Arkansas submitted a SIP revision to EPA in response to the SSM SIP Call to remove Rule 19.602 from the EPA approved SIP.

This was granted by EPA effective November 22, 2023, and thus as of that date Rule 19.602 no longer provided a complete affirmative defense to an EPA enforcement action or citizen suit under the Clean Air Act, even though it remained in Rule 19 and provides a defense against actions by DEQ. 

Rule 19.1004(H) stated that under certain conditions “sudden and unavoidable breakdown, malfunction or upset” resulting in excess emissions does not constitute a violation with respect to VOC sources in Pulaski County. 

In May 2022, while the Florida Electric lawsuit was pending, Arkansas also requested that this provision be removed completely from the approved SIP. This request was granted by EPA effective November 22, 2023. 

PA has been given an extension of time until May 15, 2024 to file a petition for rehearing in the Florida Electric case. Consequently, it is possible that the decision may be overturned, especially in light of the strenuous dissent. Furthermore, the Court pointed out that its decision did not preclude EPA from re-promulgating the SIP Call – if it made proper findings in accordance with the Court’s decision. Although the State of Arkansas may have acted prematurely in removing Rule 19.602 from the EPA approved SIP, it remains to be seen whether Rule 19.602 will or would have ultimately withstood EPA’s SSM SIP Call.