By Jeryl L. Olson, Rebecca A. DavisAndrew H. PerellisPatrick D. Joyce, and Craig B. Simonsen

Seyfarth Synopsis: The U.S. Environmental Protection Agency (EPA or Agency) has released a pre-publication copy of its proposed amendments to the Air Toxics Standards for Industrial, Commercial, and Institutional Boilers and Process Heaters at Major Source Facilities, 40 CFR Part 63. The proposed rules establish new emissions limits for a large number of chemicals, and impose significant obligations on affected parties utilizing a variety of boilers.

The current version of the national emission standards for the control of hazardous air pollutants (NESHAP) were finalized with amendments in 2013 for the purpose of controlling hazardous air pollutants (HAP) at major sources from new and existing industrial, commercial, and institutional boilers and process heaters. The currently proposed amendments are EPA’s response to three separate remands from decisions of the United States Court of Appeals for the District of Columbia Circuit.

The first two remands both arise out of the 2016 case of U.S. Sugar Corp. v. EPA. In the first remand, the Court sought further explanation for emission standards for subcategories of boilers where it determined EPA had improperly excluded certain units in calculating maximum achievable control technology (MACT) floor emission limits. In the second remand, the U.S. Sugar Corp. Court also remanded for EPA to provide further explanation regarding its decision to use carbon monoxide (CO) as a surrogate for organic HAP emissions. The third remand was from March 2018 where, in the case of Sierra Club, et al. v. EPA, the Court remanded for “further explanation EPA’s decision to set a limit of 130 ppm CO as a minimum standard for certain subcategories of boilers.”

To address the first remand the amendments propose 34 recalculated MACT emission limits for certain subcategories of boilers. To resolve the other two remands, the proposed amendments provide the Court with an explanation on available control technologies to reduce organic HAP emissions without involving CO, and to address whether the best performing boilers might be using alternative control technologies to reduce organic HAP. The proposed amendments also explain “EPA’s decision to establish 130 parts per million (ppm) as the lowest (i.e., most stringent) emission limit for CO consistent with the requirements of the Clean Air Act.”

While according to the Agency, the proposed changes will protect air quality and reduce emissions of HAPs, the Agency also admits the rules, if adopted, will only reduce HAPS by 244 tons per year, at a cost to industry of more than $21.5 million (that is, a cost of $88,000 per ton of reduction).

The Agency notes that if “anyone contacts us requesting a public hearing on or before [5 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER], it will hold a virtual public hearing. Comments may be submitted to Docket ID No. EPA-HQ-OAR-2002-0058, or by email to, Attention Docket ID No. EPA-HQ-OAR-2002-0058.

For more information on this or any related topic please contact the authors, your Seyfarth attorney, or any member of the Seyfarth Environmental Compliance, Enforcement & Permitting Team.