United States Court of Appeals, District of Columbia Circuit
Petition of the United States Environmental Protection Agency
for Panel Rehearing as to Remedy
Before: Henderson, Brown, and Griffith, Circuit Judges.
the many challenges to the EPA's Major Boilers
in these consolidated cases, we granted the petition brought
by the Environmental Petitioners to review the EPA's
decision to exclude certain sources from its calculation of
Maximum Achievable Control Technology (MACT) emissions
standards for major-boiler subcategories, and vacated any
standards that had been "affected" by the flawed
calculation. U.S. Sugar Corp. v. EPA, 830 F.3d 579,
632 (D.C. Cir. 2016).
September 12, 2016, the EPA filed a petition for a panel
rehearing asking that the major-boiler standards be
"remanded to [the] EPA without vacatur for the Agency to
conduct rulemaking to determine which standards are
'affected' and to modify them in accordance with the
Court's opinion." EPA Pet. Reh'g 1. All relevant
parties in this matter support the EPA's request. Joint
Resp. Industry Pet'rs 3; Envtl. Pet'rs' Resp. 1.
remand without vacatur may in some circumstances invite
prejudicial agency delay, see, e.g., In re Core
Commc'ns, Inc., 531 F.3d 849, 862-63 (D.C. Cir.
2008) (Griffith, J., concurring), in other circumstances
vacatur itself carries more-harmful consequences. We have
therefore frequently remanded without vacating when a
rule's defects are curable and "where vacatur
'would at least temporarily defeat . . . the enhanced
protection of the environmental values covered by [the EPA
rule at issue].'" North Carolina v. EPA,
550 F.3d 1176, 1178 (D.C. Cir. 2008) (per curiam)
(alterations in original) (quoting Envtl. Def. Fund, Inc.
v. EPA, 898 F.2d 183, 190 (D.C. Cir. 1990)); see
also Natural Res. Def. Council v. EPA, 489 F.3d 1250,
1265 (D.C. Cir. 2007) ("Where the court has concluded
that a final rule is deficient, the court has traditionally
not vacated the rule if doing so would have serious adverse
implications for public health and the environment.").
Vacating the standards at issue here would unnecessarily
remove many limitations on emissions of hazardous air
pollutants from boilers and allow greater emissions of those
pollutants until EPA completes another rulemaking and
implements replacement standards. See EPA Pet.
light of our precedent and the parties' agreement that
this case presents one of the circumstances in which remand
without vacatur makes the most sense, we remand without
vacating the numeric MACT standards set in the Major Boilers
Rule for new and existing sources in each of the eighteen
subcategories. On remand, the EPA is to identify those
standards for which the MACT floor would have differed if the
EPA had included all best-performing sources in each
subcategory in its MACT-floor analysis. The EPA must then
revise those standards consistent with our July 29, 2016
opinion in this case.
the Industry Petitioners stress the importance of the EPA
expeditiously completing the rulemaking, we have not been
asked to impose a deadline by which the EPA must act. Even
so, we expect the EPA to complete this rulemaking promptly.
We also "remind the Petitioners that they may bring a
mandamus petition to this court in the event that [the] EPA
fails to" revise its standards on remand "in a
manner consistent with our" earlier opinion. North
Carolina, 550 F.3d at 1178 (citing Natural Res. Def.
Council, 489 F.3d at 1264 (Randolph, J., concurring)).
 National Emission Standards for
Hazardous Air Pollutants for Major Sources: Industrial,
Commercial, and Institutional Boilers and Process Heaters, 76
Fed. Reg. 15, 608 (Mar. 21, 2011), as amended,
National Emission Standards for Hazardous Air Pollutants for
Major Sources: Industrial, Commercial, and Institutional
Boilers and Process Heaters, 78 Fed. Reg. 7, 138 (Jan. 31,
 Because the parties agree as to the
appropriate remedy, a formal rehearing is