 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued December 10, 2013              Decided March 11, 2014

                        No. 12-1166

             UTILITY AIR REGULATORY GROUP,
                       PETITIONER

                             v.

          ENVIRONMENTAL PROTECTION AGENCY,
                    RESPONDENT

             EDGECOMBE GENCO, LLC, ET AL.,
                    INTERVENORS


            Consolidated with 12-1366, 12-1420


       On Petitions for Review of Final Action of the
       United States Environmental Protection Agency


     Lauren E. Freeman argued the cause for Industry
Petitioners. With her on the briefs were Craig S. Harrison,
Greg Abbott, Attorney General, Office of the Attorney General
for the State of Texas, Jon Niermann, Chief, Environmental
Protection Division, and Mark Walters and Mary E. Smith,
Assistant Attorneys General. Elizabeth L. Horner entered an
appearance.
                                2

    David B. Rivkin, Jr., Lee A. Casey, Mark W. DeLaquil,
Andrew M. Grossman, Lisa M. Jaeger, Eric A. Groten, and
Jeremy C. Marwell were on the brief for intervenors Edgecomb
Genco, LLC, et al. in support of petitioners.

     Amanda Shafer Berman, Attorney, U.S. Department of
Justice, argued the cause for respondent. On the brief were
Robert G. Dreher, Acting Assistant Attorney General, and
Norman L. Rave, Jr., Attorney. Eric G. Hosteller and Matthew
R. Oakes, Attorneys, entered appearances.

     Pamela A. Campos, argued the cause for Environmental
Intervenors in support of respondent. With her on the briefs
were Tomás E. Carbonell, Shannon Smyth, James S. Pew, Neil
E. Gormley, Sean H. Donahue, Sanjay Narayan, John D. Walke,
and John T. Suttles.

   Before: GARLAND, Chief Judge, and ROGERS and
KAVANAUGH, Circuit Judges.

    Opinion for the Court filed by Chief Judge GARLAND.

    Concurring opinion filed by Circuit Judge KAVANAUGH.

     GARLAND, Chief Judge: The Utility Air Regulatory Group
and the State of Texas challenge 2009 and 2012 final rules
issued by the Environmental Protection Agency (EPA) under the
Clean Air Act. The rules revised the new source performance
standards for steam generating units. Several of the petitioners’
challenges are not properly before us because they were first
raised in petitions for reconsideration that remain pending before
the agency. We reject the petitioners’ remaining challenges and
deny the petitions for review.
                                3

                                 I

     The Clean Air Act directs the EPA Administrator to publish
and periodically revise a list of categories of stationary sources,
which are large, fixed sources of air pollution. 42 U.S.C.
§ 7411(a)(3), (b)(1)(A). The Administrator must include a
category of sources in this list “if in his judgment it causes, or
contributes significantly to, air pollution which may reasonably
be anticipated to endanger public health or welfare.” Id.
§ 7411(b)(1)(A). Once a source category is listed, the
Administrator must establish new source performance standards
for that category. Id. § 7411(b)(1)(B).1

    Fossil-fuel-fired steam generating units are boilers that
produce electricity. In so doing, they emit particulate matter
into the atmosphere. Because EPA determined that those
emissions “may contribute significantly to air pollution which
causes or contributes to the endangerment of public health or
welfare,” List of Categories of Stationary Sources, 36 Fed. Reg.
5931, 5931 (Mar. 31, 1971), it promulgated new source
performance standards for those units. The regulations are
divided into four subparts within 40 C.F.R. Part 60 -- Subparts




    1
      A “new source” is “any stationary source, the construction or
modification of which is commenced after the publication of
regulations . . . prescribing a standard of performance under this
section which will be applicable to such source.” 42 U.S.C.
§ 7411(a)(2). A “standard of performance” is “a standard for
emissions of air pollutants which reflects the degree of emission
limitation achievable through the application of the best system of
emission reduction which (taking into account the cost of achieving
such reduction and any nonair quality health and environmental
impact and energy requirements) the Administrator determines has
been adequately demonstrated.” Id. § 7411(a)(1).
                                  4

D, Da, Db, and Dc -- each of which concerns a specific group of
sources.2

     To ensure that steam generating units comply with emission
limits, EPA requires that they measure the particulate matter in
their emissions.      When EPA initially promulgated the
regulations, the only way to measure such emissions was to
perform a manual test. See Standards of Performance for New
Stationary Sources, 36 Fed. Reg. 24,876, 24,888-90 (Dec. 23,
1971). To provide an alternative (and less expensive) way to
assess compliance, EPA later added opacity standards to its
boiler rules. See Standards of Performance for New Stationary
Sources: Additions and Miscellaneous Amendments, 39 Fed.
Reg. 9308, 9308-09 (Mar. 8, 1974). Opacity is not a pollutant
but rather can serve as a proxy for pollutants: It measures the
degree to which stack emissions block the transmission of light.
Opacity can be measured by (among other things) visual
inspection by a trained observer or by a continuous opacity
monitoring system (COMS). A COMS requires the installation
of equipment in the steam generating unit’s stack. This


     2
      Subpart D covers fossil-fuel-fired electric utility steam
generating units (EGUs) of greater than 73 megawatts (MW) heat
input capacity, on which construction, modification, or reconstruction
commenced after August 17, 1971 and on or before September 18,
1978. See 40 C.F.R. § 60.40(a). Subpart Da covers EGUs of greater
than 73 MW heat input capacity on which construction, modification,
or reconstruction began after September 18, 1978. See id.
§ 60.40Da(a). Subpart Db covers industrial-commercial-institutional
steam generating units with a heat input capacity of greater than 29
MW on which construction, modification, or reconstruction began
after June 19, 1984. See id. § 60.40b(a). And Subpart Dc covers
industrial-commercial-institutional steam generating units with a heat
input capacity of between 2.9 and 29 MW, on which construction,
modification, or reconstruction began after June 9, 1989. See id.
§ 60.40c(a).
                               5

equipment shines a light beam through stack gases and records
the resulting opacity readings at fixed intervals.

     A newer form of monitoring technology is a continuous
emissions monitoring system (CEMS). A CEMS, like a COMS,
requires the installation of monitoring equipment in the unit’s
stack. But a CEMS measures pollutants directly, rather than by
measuring opacity as a proxy. Both a CEMS and a COMS
measure only filterable particulate matter -- which is emitted
from the stack as a solid. They do not measure condensable
particulate matter -- which is emitted as a gas, but turns liquid
or solid upon exiting the stack. Visual inspection, by contrast,
can measure both. Historically, however, only filterable
particulate matter has been subject to emission limitations.

     In 2006 and 2007, EPA gave facilities the option of
installing particulate matter CEMS as “an alternative method to
demonstrate continuous compliance and as an alternative to
opacity . . . monitoring requirements.”           Standards of
Performance [for Subparts Da, Db, and Dc Units], 71 Fed. Reg.
9866, 9867-68 (Feb. 27, 2006); see Standards of Performance
[for Subparts D, Da, Db, and Dc Units], 72 Fed. Reg. 32,710,
32,719 (June 13, 2007). The agency said that, because
particulate matter CEMS “measure the pollutant of primary
interest they provide adequate assurance of [particulate matter]
control device performance, and continuous opacity monitoring
is an unnecessary burden to affected sources using” CEMS.
Standards of Performance [for Subparts D, Da, Db, and Dc
Units]; Reconsideration and Amendments, 72 Fed. Reg. 6320,
6322 (proposed Feb. 9, 2007). EPA did not, however, eliminate
the opacity standards themselves; it merely said that facilities
using CEMS were no longer required to install and operate
COMS. See Standards of Performance [for Subparts D, Da, Db,
and Dc Units], 73 Fed. Reg. 33,642, 33,644 (proposed June 12,
2008) [hereinafter 2008 Proposal].
                                 6

     In 2008, EPA published a notice of proposed rulemaking,
seeking comment on the possible elimination of opacity
standards altogether for facilities using CEMS. See id. at
33,646. The agency said that elimination of such standards at
those units might be appropriate, “[s]ince opacity data has been
used as a surrogate for [particulate matter] emissions and since
[particulate matter] CEMS give a more direct continuous
measurement of the primary pollutant of interest causing
opacity.” Id. (footnote omitted). EPA noted, however, that
opacity is useful not only as a proxy for pollutants, but also “as
an indicator of control device operation and proper
maintenance.” Id. at 33,646 n.1.

     The 2009 final rule exempted all units using particulate
matter CEMS from all opacity standards and monitoring
requirements, but conditioned the exemption on their
compliance with an emission standard for filterable particulate
matter of 0.03 pounds per million British thermal units
(lb/MMBtu) or less, rather than any otherwise applicable, higher
limits. See Standards of Performance [for Subparts D, Da, Db,
and Dc Units], 74 Fed. Reg. 5072, 5073-74 (Jan. 28, 2009)
[hereinafter 2009 Rule]. For Subpart D units, for example, the
higher limit was 0.10 lb/MMBtu. See 40 C.F.R. § 60.42.3

    If a unit that was using a particulate matter CEMS did not
comply with the lower limit, the 2009 rule required it “to either
use a COMS or perform periodic visual inspections to comply
with the opacity standard.” Id. at 5074. The frequency of such
inspections depended on the results of the most recent
inspection. See id. In addition, the rule required all facilities to


    3
      By the time of the 2009 Rule, Subpart Da units were already
required to comply with the 0.03 lb/MMBtu limit, see 40 C.F.R.
§ 60.42Da (2007), as were certain, newer Subparts Db and Dc units,
see id. §§ 60.43b(h)(1), 60.43c(e)(1) (2007).
                                7

measure and report emissions of condensable particulate matter.
See id. at 5073.

     UARG filed a petition for reconsideration of the 2009 rule.
Among other things, it asked EPA to reconsider its decision to
limit the exemption from the opacity standard and monitoring
requirements to units complying with the 0.03 lb/MMBtu
emission standard. EPA granted the petition for reconsideration.
At the same time, it published notice of a new proposed rule. In
most respects, the proposal tracked the 2009 final rule. It
contained only two differences relevant here: First, EPA
proposed a total (that is, filterable plus condensable) particulate
matter emission limit for certain Subpart Da units on which
construction, reconstruction, or modification commenced after
May 3, 2011. Second, EPA proposed to add an affirmative
defense to civil penalties for exceedances of emission limits that
are caused by malfunctions. See Standards of Performance [for
Subparts D, Da, Db, and Dc Units], 76 Fed. Reg. 24,976,
25,061, 25,064, 25,071 (proposed May 3, 2011) [hereinafter
2011 Proposal].

     Thereafter, UARG submitted a new round of comments. It
argued that EPA should exempt all Subpart D units using CEMS
from the opacity standard and monitoring requirements because
CEMS are sufficiently accurate to ensure compliance with
emission standards. The Texas Commission on Environmental
Quality also submitted comments urging EPA to revise its rules
to allow steam generating units to use state-law affirmative
defenses in lieu of the federal affirmative defense the agency
had proposed.

    On February 16, 2012, EPA issued another final rule.
Standards of Performance [for Subparts D, Da, Db, and Dc
Units], 77 Fed Reg. 9304 (Feb. 16, 2012) [hereinafter 2012
Rule]. The 2012 rule did not expand the exemption from the
                                8

opacity standard or monitoring requirements. Id. at 9424.
Although it reduced the frequency of periodic visual opacity
inspections for Subpart Da facilities not using COMS, see id. at
9457, it did not do so for Subparts D, Db, and Dc facilities, see
id. at 9448, 9460, 9463. The 2012 rule also required certain
Subpart Da units -- those on which construction, reconstruction,
or modification commenced after May 3, 2011 -- to test for
condensable particulate matter. See id. at 9458. Finally, the rule
did not allow the use of state-law affirmative defenses. Id. at
9433.

     Thereafter, UARG and the State of Texas filed petitions for
agency reconsideration as well as for judicial review. EPA has
not yet acted on the petitions for reconsideration. The petitions
for judicial review are now before us.

                                II

     We begin with two issues regarding the scope of our
review: the law that determines which of the petitioners’
challenges are properly before us, and the standards for
reviewing those challenges that are.

                                A

     This court’s general view is that “a pending petition for
[agency] rehearing . . . render[s] the underlying agency action
nonfinal (and hence unreviewable) with respect to the filing
party.” United Transp. Union v. ICC, 871 F.2d 1114, 1116
(D.C. Cir. 1989); see, e.g., Clifton Power Corp. v. FERC, 294
F.3d 108, 110-12 (D.C. Cir. 2002). In the 1990 Amendments to
the Clean Air Act, however, Congress made clear that this does
not apply to challenges to rules promulgated under the Act. A
provision of 42 U.S.C. § 7607(b)(1) states: “The filing of a
petition for reconsideration by the Administrator of any
                                 9

otherwise final rule or action shall not affect the finality of such
rule or action for purposes of judicial review . . . .” 42 U.S.C.
§ 7607(b)(1). The Senate Report accompanying the Clean Air
Act Amendments confirms that the purpose of that provision
was to “overrule,” in the context of the Clean Air Act, the
holding in West Penn Power Co. v. EPA, 860 F.2d 581, 583 (3d
Cir. 1988), that a pending petition for reconsideration deprives
an agency action of finality. S. REP. NO. 101-228, at 3755
(1989). West Penn was one of the cases upon which this court
relied in adopting our general view. See United Transp. Union,
871 F.2d at 1117-18.

      Nonetheless, even under the Clean Air Act, a party may not
raise for judicial review objections to a rule that it raised for the
first time in a petition for agency reconsideration -- at least until
that petition is resolved. The Act states:

         Only an objection to a rule or procedure which was
         raised with reasonable specificity during the period for
         public comment . . . may be raised during judicial
         review. If the person raising an objection can
         demonstrate to the Administrator that it was
         impracticable to raise such objection within such time
         or if the grounds for such objection arose after the
         period for public comment . . . and if such objection is
         of central relevance to the outcome of the rule, the
         Administrator shall convene a proceeding for
         reconsideration of the rule . . . . If the Administrator
         refuses to convene such a proceeding, such person may
         seek review of such refusal in the United States court
         of appeals for the appropriate circuit . . . .

42 U.S.C. § 7607(d)(7)(B).
                                 10

     The first sentence of this subsection flatly states that “[o]nly
an objection to a rule or procedure which was raised . . . during
the period for public comment . . . may be raised during judicial
review.” Standing alone, the sentence indicates that an
objection raised for the first time in a petition for
reconsideration may not be raised in court, because such an
objection was, by definition, not raised “during the period for
public comment.”

     The second and third sentences create a limited exception
to the bar imposed by the first. As the second sentence states, if
it was impracticable to raise a particular objection during the
comment period or the grounds for the objection arose after that
period, and if the objection is of central relevance to the
outcome of the rule, “the Administrator shall convene a
proceeding for reconsideration of the rule.” Presumably, a party
can seek judicial review of the outcome of such a
reconsideration proceeding. But that sentence (together with the
one that precedes it) would be pointless if a court could hear an
objection raised for the first time in a petition for
reconsideration before the proceeding was completed.

     The third sentence indicates what a petitioner may do “if the
Administrator refuses to convene” a reconsideration proceeding.
In that circumstance, a petitioner “may seek review of such
refusal in the United States court of appeals.” And one thing the
court may then do, if the predicates for reconsideration set out
in the second sentence are satisfied, is vacate the refusal and
direct the Administrator to convene a reconsideration
proceeding. Likewise, when that proceeding is completed, the
court presumably can hear a petition for review of the outcome.
But once again, that sentence (together with the two that precede
it) would be pointless if a court could hear a new objection
before those procedural steps were completed.
                                11

     In sum, although the filing of a petition for reconsideration
does not render a Clean Air Act rule nonfinal for purposes of
judicial review, the only objections that may immediately be
raised upon judicial review are those that were raised during the
public comment period. Objections raised for the first time in
a petition for reconsideration must await EPA’s action on that
petition. See Oklahoma v. EPA, 723 F.3d 1201, 1214-15 (10th
Cir. 2013); see generally Appalachian Power Co. v. EPA, 249
F.3d 1032, 1055, 1065 (D.C. Cir. 2001); North Dakota v. EPA,
730 F.3d 750, 770-71 (8th Cir. 2013).

      At oral argument, UARG maintained that, even if it cannot
obtain judicial review of substantive challenges raised for the
first time in a still-pending petition for reconsideration, it can
obtain judicial review of procedural challenges raised for the
first time in such a petition. But the language of the Clean Air
Act forecloses that argument. See 42 U.S.C. § 7607(d)(7)(B)
(“Only an objection to a rule or procedure which was raised
with reasonable specificity during the period for public
comment . . . may be raised during judicial review.” (emphasis
added)); see also Appalachian Power Co., 249 F.3d at 1055;
Oklahoma, 723 F.3d at 1214-15. Accordingly, because EPA has
not yet resolved the petitioners’ petitions for reconsideration, the
only objections that are properly before us are those the
petitioners made during the public comment periods.

                                 B

    We may vacate a final rule promulgated under the Clean
Air Act if it is “arbitrary, capricious, an abuse of discretion, or
otherwise not in accordance with law.”                 42 U.S.C.
§ 7607(d)(9)(A). To determine whether a rule is arbitrary or
capricious, we apply the same standard of review that we apply
under the Administrative Procedure Act (APA), 5 U.S.C.
§ 706(2)(A). See Allied Local & Reg’l Mfrs. Caucus v. EPA,
                                12

215 F.3d 61, 68 (D.C. Cir. 2000). “[W]e must affirm the EPA’s
rules if the agency has considered the relevant factors and
articulated a rational connection between the facts found and the
choice made.” Id. (internal quotation marks omitted).

     As under the APA, we may also vacate a rule under the
Clean Air Act if it was promulgated “without observance of
procedure required by law.” 42 U.S.C. § 7607(d)(9)(D); see 5
U.S.C. § 706(2)(D). But the Clean Air Act tacks on three
additional conditions. To vacate a Clean Air Act rule on the
ground that the agency failed to observe a procedural
requirement, we must also find that “(i) such failure to observe
such procedure is arbitrary or capricious, (ii) the requirement of
paragraph (7)(B) has been met, and (iii) the condition of the last
sentence of paragraph (8) is met.” 42 U.S.C. § 7607(d)(9)(D).
The second condition is a reference to the requirement of
§ 7607(d)(7)(B), which we discussed in Part II.A above. The
third condition provides that “the court may invalidate the rule
only if the errors were so serious and related to matters of such
central relevance to the rule that there is a substantial likelihood
that the rule would have been significantly changed if such
errors had not been made.” Id. § 7607(d)(8).

                                III

     The petitioners raise several challenges that are not properly
before us. They object to the following: the 2012 rule’s
condensable particulate matter testing requirement for Subpart
Da units; the rule’s establishment of a different frequency for
periodic visual opacity inspections under Subparts D, Db, and
Dc than under Subpart Da; and the agency’s suggestion that it
would permit the use of state-law affirmative defenses in the
context of the mercury and air toxics (MATS) emission
standards for coal- and oil-fired electric utility steam generating
units (EGUs), issued pursuant to 42 U.S.C. § 7412, while not
                                  13

allowing such defenses in the context of new source
performance standards under § 7411. It is undisputed the
petitioners did not make these objections during the public
comment period. Although they did raise them in their petitions
for reconsideration, those petitions remain pending before the
agency. Accordingly, for the reasons discussed in Part II.A,
these challenges are not properly before us.4

     The following subsections address the objections that the
petitioners did raise during the comment period.

                                  A

     UARG challenges the requirement -- included in the 2009
rule and reaffirmed in the 2012 rule -- that Subparts D, Db, and
Dc boilers emitting more than 0.03 lb/MMBtu of particulate
matter remain subject to the opacity standard and must install
COMS or perform periodic visual opacity inspections, even if
they use particulate matter CEMS.



     4
      It is true that our cases have said EPA retains a “duty to examine
key assumptions as part of its affirmative burden of promulgating and
explaining a non-arbitrary, non-capricious rule and therefore . . . must
justify [such an] assumption even if no one objects to it during the
comment period.” Okla. Dep’t of Envtl. Quality v. EPA, 740 F.3d
185, 192 (D.C. Cir. 2014) (alteration in original) (internal quotation
marks omitted); see, e.g., Ne. Md. Waste Disposal Auth. v. EPA, 358
F.3d 936, 948 (D.C. Cir. 2004). But unlike the petitioners in the cited
cases, the petitioners here did not merely fail to object to assumptions
(whether “key” or not) underlying the requirements and distinctions
they now challenge in court; rather, they did not object to those
requirements or distinctions at all. Although the petitioners may have
had good reason for not raising those objections during the
rulemaking, judicial review must nonetheless await EPA’s action on
their petitions for reconsideration. See supra Part II.A; infra note 7.
                                 14

     1. UARG contends that continuing to subject boilers
emitting more than 0.03 lb/MMBtu of particulate matter to an
opacity standard and opacity monitoring requirements, while
exempting boilers emitting that amount or less, was arbitrary
and capricious. We disagree. In its 2009 rule, EPA explained
that sources emitting 0.03 lb/MMBtu or less of particulate
matter “will operate with little or no visible emissions,” and thus
“an opacity standard is no longer necessary for these sources.”
2009 Rule, 74 Fed. Reg. at 5073. “At this emission rate,” the
agency said, the existence of any “visible emissions may
indicate that the [particulate matter] control device is not
operating properly.” Id. at 5074. Hence, for a source that is
meeting this emission standard, no opacity standard is needed
because any visible opacity will indicate improper operation.

     By contrast, units emitting more than 0.03 lb/MMBtu of
particulate matter “may have some visible emissions” even if
their particulate matter control devices are operating properly.
Id. Since particulate matter “CEMS readings cannot be verified
as readily as other CEMS, and since recalibration requires
[particulate matter] performance tests, baseline opacity readings
can be a valuable secondary check on control device
performance and [particulate matter] emissions.”               Id.
Accordingly, the agency reasonably concluded that a unit
emitting more than 0.03 lb/MMBtu should remain “subject to an
opacity limit” and “use a COMS or perform periodic visual
inspections to comply with the opacity standard” to verify that
the pollution control and monitoring systems are operating
properly. Id.5


     5
       The petitioners maintain that, in the 2012 rule, EPA renounced
this rationale for subjecting boilers emitting more than 0.03 lb/MMBtu
of particulate matter to an opacity standard. We disagree. The agency
did add another explanation in its response to comments, but nothing
in that response suggests that it renounced its earlier rationale. See
                                15

     UARG also contends that EPA was unreasonable, not just
in retaining an opacity standard for units emitting more than
0.03 lb/MMBtu of particulate matter, but also in requiring them
to use a COMS or perform periodic visual opacity inspections.
But as just explained, the purpose of retaining the opacity
standard for such a unit is to provide a real-time check to ensure
that its particulate matter control device is functioning properly.
See 2009 Rule, 74 Fed. Reg. at 5073-74; 2008 Proposal, 73 Fed.
Reg. at 33,646 n.1. Using a COMS or performing periodic
visual opacity inspections provides that check. See id. Because
EPA has articulated a reasonable explanation for requiring
opacity monitoring, petitioner’s challenge to this requirement
fails.

     We also reject UARG’s related contention that EPA’s
action was arbitrary and capricious because it failed to address
“the impacts of the periodic visible emissions testing on the
Subpart D units it had proposed to exempt from the standard, but
did not exempt in the final rule.” Pet’rs’ Br. 35. Whether or not
a failure to consider the burden imposed on those units would
have been arbitrary and capricious, the contention fails because
EPA did consider the burden imposed by its visual opacity
inspection requirement. See 2009 Rule, 74 Fed. Reg. at 5074;
see also 2008 Proposal, 73 Fed. Reg. at 33,643 (noting that the
proposal, which included visual opacity inspection requirements,
“would not significantly change our original projections for the
rule’s compliance costs, . . . burden on industry, or the number
of affected facilities”); id. at 33,645 (noting that “the use of a
digital camera system” to comply with the opacity monitoring
requirements “would also reduce compliance costs”); 2012 Rule,



EPA, Response to Public Comments on Rule Amendments Proposed
May 3, 2011 (73 FR 33642) [hereinafter 2011 Response to
Comments] at 13-14 (Dec. 2011) (J.A. 211-12).
                                 16

77 Fed. Reg. at 9425 (analyzing the power industry’s
compliance costs).

     2. UARG further contends that, in promulgating the 2009
rule, EPA violated the Clean Air Act’s rulemaking provisions.
According to UARG, in 2008 “EPA proposed one rule (the full
opacity exemption) based on its longstanding positions . . . , and
then adopted a very different rule without any notice of its new
rationale or positions.” Pet’rs’ Br. 31. But even assuming that
EPA did stumble procedurally during the rulemaking for the
2009 rule, it made up for any procedural error during the
rulemaking for the 2012 rule. There is no dispute that, during
the latter, EPA offered all interested parties an opportunity to
comment on both the opacity standard and the opacity
monitoring requirements.         Because thereafter EPA re-
promulgated the same standard and requirements, UARG’s
procedural objection to the allegedly inadequate notice and
opportunity to comment is moot. See NRDC v. U.S. Nuclear
Regulatory Comm’n, 680 F.2d 810, 813-14 (D.C. Cir. 1982); see
also Fund for Animals, Inc. v. Hogan, 428 F.3d 1059, 1063-64
(D.C. Cir. 2005). So, too, is its contention that EPA failed to
respond to comments on the 2008 proposal. See NRDC v. U.S.
Nuclear Regulatory Comm’n, 680 F.2d at 813-14.6



    6
     UARG also argues that EPA violated the Paperwork Reduction
Act by failing to submit to the Office of Management and Budget an
information collection request to support its condensable particulate
matter testing requirement. See 44 U.S.C. § 3507(a). But even if that
were true, a violation of the Paperwork Reduction Act does not afford
an independent cause of action; it merely serves as a defense to an
enforcement action. See id. § 3512; Dithiocarbamate Task Force v.
EPA, 98 F.3d 1394, 1405 (D.C. Cir. 1996); see also, e.g., Sutton v.
Providence St. Joseph Med. Ctr., 192 F.3d 826, 844 (9th Cir. 1999).
No such action is before us.
                               17

                               B

    Texas’ petition for review challenges EPA’s refusal to
allow state-law affirmative defenses against the enforcement of
new source performance standards.

     As noted earlier, see supra Part I, EPA’s 2011 notice
proposed adding an affirmative defense to civil penalties when
a facility exceeds emission limits as a result of a malfunction.
See 2011 Proposal, 76 Fed. Reg. at 25,064. EPA proposed that
the defense be available only “where the event that causes an
exceedance of the emission limit” is “sudden, infrequent, not
reasonably preventable and not caused by poor maintenance and
or careless operation.” Id. In its comments during the
rulemaking, Texas asked EPA to consider allowing states to use
their own state-law affirmative defenses in lieu of the federal
defense that EPA proposed. Specifically, Texas wanted to use
the affirmative defense provisions in its State Implementation
Plan (SIP), which EPA had previously approved under a
different Clean Air Act provision, 42 U.S.C. § 7410. The 2012
final rule permitted the federal defense only.

     Texas maintains that EPA did not explain why it declined
to approve Texas’ use of a state-specific affirmative defense for
the new source performance standards under 42 U.S.C. § 7411,
when it had approved such a defense in its SIP under § 7410.
But EPA did explain: Unlike some other Clean Air Act
standards, new source performance standards are not
incorporated into SIPs as state-promulgated regulations. Rather,
they are federal standards to which SIP affirmative defense
provisions are inapplicable. See 2011 Response to Comments
at 26 (J.A. 215).

    Texas protests that this explanation is arbitrary and
capricious because EPA suggested, in responding to comments
                                   18

in a different rulemaking, that it would permit state-specific
affirmative defenses with respect to different emission standards
-- the mercury and air toxics (MATS) emission standards for
coal- and oil-fired EGUs, issued pursuant to 42 U.S.C. § 7412.
Although EPA’s brief offers the agency’s explanation for the
difference (based on differences between the state-delegation
aspects of the new source performance and MATS rules, see
EPA Br. 30-32), we do not address that explanation. As we
noted above, supra Part III (introduction), Texas did not bring
this alleged inconsistency to EPA’s attention until its petition for
reconsideration. As a consequence, it may not raise this
objection for judicial review until that petition is resolved. See
supra Part II.A.7

                                   IV

     For the foregoing reasons, the petitions for review are

                                                                Denied.




     7
      It does appear that Texas had good reason for not raising the
point during the rulemaking: EPA’s response regarding the MATS
comments was not published until the public comment period for the
new source performance standards rule had closed. See EPA’s
Responses to Public Comments on EPA’s National Emission
Standards for Hazardous Air Pollutants from Coal- and Oil-Fired
EGUs (Dec. 2011) (J.A. 167); 2011 Proposal, 76 Fed. Reg. at 24,976
(“Comments must be received on or before July 5, 2011.”). But as we
explained in Part II.A, although this may qualify Texas for the limited
exception to the statutory bar against raising objections not raised
during a rulemaking, see 42 U.S.C. § 7607(d)(7)(B), the State must
nonetheless wait to raise its objection until EPA acts on its petition for
reconsideration. See Oklahoma, 723 F.3d at 1214-15; Appalachian
Power, 249 F.3d at 1065.
     KAVANAUGH, Circuit Judge, concurring: I join the Court’s
opinion. I note simply that the Section 7607 exhaustion/finality
rule we describe today likely should not be considered
jurisdictional under the Supreme Court’s recent cases that have
tightened the definition of when a rule is considered
jurisdictional. See generally Sebelius v. Auburn Regional
Medical Center, 133 S. Ct. 817, 824 (2013) (“To ward off
profligate use of the term jurisdiction, we have adopted a readily
administrable bright line for determining whether to classify a
statutory limitation as jurisdictional. We inquire whether
Congress has clearly stated that the rule is jurisdictional; absent
such a clear statement, we have cautioned, courts should treat
the restriction as nonjurisdictional in character.”) (citations,
internal quotation marks, and alteration omitted); Gonzalez v.
Thaler, 132 S. Ct. 641, 648 (2012) (“Recognizing our less than
meticulous use of the term in the past, we have pressed a stricter
distinction between truly jurisdictional rules, which govern a
court’s adjudicatory authority, and nonjurisdictional claim-
processing rules, which do not.”) (internal quotation marks
omitted); Henderson ex rel. Henderson v. Shinseki, 131 S. Ct.
1197, 1202-03 (2011) (“We have urged that a rule should not be
referred to as jurisdictional unless it governs a court’s
adjudicatory capacity, that is, its subject-matter or personal
jurisdiction. Other rules, even if important and mandatory, we
have said, should not be given the jurisdictional brand.”)
(citations omitted).

     To be sure, at least one case of ours has referred to the
Section 7607 rule as jurisdictional. See National Association of
Clean Water Agencies v. EPA, 734 F.3d 1115, 1158 (D.C. Cir.
2013). But our statement in that case was based on a prior case
that pre-dated some of the Supreme Court’s more recent
pronouncements on the jurisdiction label. Of course, the
question of whether such a rule is jurisdictional matters only in
those cases where the agency has waived or forfeited reliance on
                                 2

the rule, which is to say not often. Although we do not need to
address the question in this case, in an appropriate case where it
makes a difference, we may want to ensure that our case law on
the jurisdictional status of this particular exhaustion/finality rule
has kept pace with the Supreme Court’s case law on when a rule
should be considered jurisdictional.
