Litigation that began in 1998 over EPA’s compliance with CAA requirements for seven air toxic pollutants and continues today provides an example of the persistent litigation that has become the normal course for regulatory promulgation.

The 1990 amendments of the CAA, 42 U.S.C. §7412(c)(6), set deadlines requiring EPA to list categories and subcategories of sources of seven specific hazardous air pollutants (HAP) – alkylated lead compounds, polycyclic organic matter (POM), hexachlorobenzene (HCB), mercury, polychlorinated biphenyls (PCB), 2,3,7,8-tetrachlorodibenzofurans, and 2,3,7,8-tetrachlorodibenzo-p-dioxin. These pollutants were specified for their persistent and bioaccumulative nature. EPA was required to list source categories and subcategories to account for 90 percent of the emissions of these pollutants to assure they would be subject to maximum achievable control technology (MACT) standards. The statute required EPA to complete this requirement by November 15, 2000.

In 1998, EPA published an initial list of source categories and subcategories it anticipated would have to be subject to MACT standards to meet the 90 percent threshold. EPA found that the 90 percent threshold had been met for five of the seven pollutants and added two more source categories to assure standards would be set for all seven pollutants. The EPA finding was challenged in the D.C. Circuit Court but was dismissed after the court found that the CAA specifically precluded review of the agency's source-listing until after the agency had issued emissions standards. Sierra Club then filed petitions for review with EPA requesting additional standards for the pollutants because existing standards were allegedly inadequate. EPA denied the petitions on the ground that the standards challenged by Sierra Club were sufficient to meet the requirements necessary to be counted towards meeting the 90 percent threshold.

In 2001, Sierra Club sued EPA in the U.S. District Court for the District of Columbia asserting that EPA had failed to meet the November 15, 2000 statutory deadline. EPA asserted that it intended, once emissions standards for remaining source categories were complete, to “issue a notice that explains how it has satisfied the requirements of § 112(c)(6) in terms of issuing standards for source categories that account for the statutory thresholds identified in §112(c)(6).” The district court set a deadline for EPA to complete its obligations, which was extended.

On March 21, 2011, EPA published a notice in the “Federal Register” that it had completed sufficient standards to meet the 90 percent requirement based on a technical memorandum that documented EPA actions to meet the CAA requirements. 76 Fed. Reg. 15308 (Mar. 21, 2011).

In 2012, Sierra Club petitioned the D.C. circuit for review of EPA's 2011 notice claiming that it was unreasonable, arbitrary, capricious and otherwise unlawful and asked that it be vacated. In addition, Sierra Club argued that the notice was legislative rulemaking and EPA failed to comply with the requisite notice-and-comment requirements. The court agreed with Sierra Club that EPA failed to meet its notice and comment obligations; therefore, it vacated the determination in 2012 and ordered EPA to fulfill its notice and comment obligations without ruling on Sierra Club’s substantive claims.

Subsequently, Sierra Club returned to the district court arguing that EPA had not complied with that court’s deadline. The district court required EPA to initiate a notice and comment rulemaking. On December 16, 2014, EPA published its proposed “Completion of Requirement to Promulgate Emissions Standards,” See 79 Fed. Reg. 74656 (Completion Rule). Sierra Club submitted extensive comments, and on June 3, 2015, EPA finalized the Completion Rule as proposed and declined to respond to most of Sierra Club’s comments dismissing them as “a belated, backdoor attack” on decades-old rules. See 80 Fed. Reg. 31,471.

In 2015, Sierra Club sued EPA again in the D.C. Circuit, this time limiting its suit to three of the seven HAPs –PCBs, POM, and HCB. In its March 2016 opening brief, Sierra Club argued that EPA’s use of pollutants for which it has already set MACT standards as “surrogates” for emissions of the listed pollutants was improper, unlawful, unreasonable and arbitrary for many reasons, including that EPA does not claim that the surrogates identify “the best achieving sources, and what they can achieve” as required by the CAA. Finally, Sierra Club argued that instead of defending the claimed surrogates in its final rule, EPA set up obstacles to judicial review by claiming that legal challenges to the reasonableness of these surrogacy claims are time-barred; a position Sierra Club claims was already rejected by the court in earlier litigation. EPA responded in its June 2016 brief that Sierra Club presents “little or no direct challenge” to the agency's determination that it met its obligations, relying on prior regulations setting emission standards for various industry sectors. Moreover, EPA claims that Sierra Club’s challenge to the previously-promulgated underlying standards used as surrogates is untimely. Final briefs were filed on July 29, and oral arguments have not yet been set.