                                                      [PUBLISH]

          IN THE UNITED STATES COURT OF APPEALS

                FOR THE ELEVENTH CIRCUIT           FILED
                 ________________________ U.S. COURT OF APPEALS
                                              ELEVENTH CIRCUIT
                                                MARCH 6, 2013
                       No. 08-16961
                                                  JOHN LEY
                 ________________________
                                                   CLERK

                 Agency No. 40 CFR PART 52


ALABAMA ENVIRONMENTAL COUNCIL,
SIERRA CLUB,
NATURAL RESOURCES DEFENSE COUNCIL,
OUR CHILDREN’S EARTH FOUNDATION,

                                                      Petitioners,

                           versus

ADMINISTRATOR, UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY,
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY,

                                                     Respondents,

ALABAMA POWER COMPANY,
TENNESSEE VALLEY AUTHORITY,
ALABAMA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT,

                                                      Intervenors.
                 ________________________

                       No. 11-11549
                 ________________________

                  Agency No. 40 CFR Part 52
ALABAMA POWER COMPANY,

                                                                                   Petitioner,

                                            versus

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY,
ADMINISTRATOR,
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY,

                                                                               Respondents,

ALABAMA ENVIRONMENTAL COUNCIL,
OUR CHILDREN’S EARTH FOUNDATION,
SIERRA CLUB,

                                                                                Intervenors.

                              ________________________

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

                                      (March 6, 2013)

Before TJOFLAT and BLACK, Circuit Judges, and MOLLOY,* District Judge.

BLACK, Circuit Judge:




       *
          Honorable Donald W. Molloy, United States District Judge for the District of Montana,
sitting by designation.

                                               2
      These consolidated appeals focus on a Clean Air Act1 visible emissions

regulation promulgated by the State of Alabama and submitted to the United

States Environmental Protection Agency (EPA) as a revision to Alabama’s State

Implementation Plan (SIP). In 2008, the EPA approved the revision after

concluding the proposed regulation satisfied the Clean Air Act’s requirements

(2008 approval). The EPA denied a timely request in 2009 that it reconsider its

approval, but, when confronted with a second reconsideration request the

following month, the EPA’s new Acting Regional Administrator granted the

request. In April of 2009, the EPA moved this Court to grant a limited voluntary

remand. We granted the motion, remanding the case “on a limited basis for

purposes of reconsidering the final rule under review.” In 2011, following such

reconsideration, the EPA disapproved the revision (2011 disapproval).

      Petitions for review of both the 2008 approval and the 2011 disapproval are

before us. Alabama Power supports the 2008 approval and asks us to affirm the

approval as the only lawful action the EPA has taken on the proposed regulation.

The Alabama Environmental Council, Sierra Club, Natural Resources Defense

Council, and Our Children’s Earth Foundation (Citizens) support the 2011




      1
          42 U.S.C. §§ 7401 et seq.

                                        3
disapproval and ask us to affirm that action. The EPA is defending the 2011

disapproval and contends we should not review the 2008 approval.

      After a discussion of the statutory background and the factual and

procedural history of the two petitions, we first consider whether the EPA’s 2011

disapproval was conducted in compliance with the statutory procedures set forth in

the Clean Air Act. We conclude the 2011 disapproval was unauthorized by the

Clean Air Act because the EPA failed to make the statutorily required error

determination. We next reject the EPA’s reliance on its inherent authority and this

Court’s remand order as authorization for the 2011 disapproval. Finally, we

address and dismiss challenges to the 2008 approval, and affirm the validity of

that action.

                              I. Statutory Background

      The Clean Air Act aims to “protect and enhance the quality of the Nation’s

air resources, ” 42 U.S.C. § 7401(b)(1), and “sets out a two-stage process for

achieving this goal,” Sierra Club v. Ga. Power Co., 443 F.3d 1346, 1348 (11th

Cir. 2006). At the first stage, the EPA identifies air pollutants that endanger the

public, then formulates national ambient air quality standards (NAAQS) to

regulate these pollutants. 42 U.S.C. § 7409; Ga. Power, 443 F.3d at 1348. At the

second stage, each state develops a SIP to ensure its air meets the NAAQS for the

                                          4
various pollutants. 42 U.S.C. § 7410; Ga. Power, 443 F.3d at 1348. The SIP must

be submitted for review by the EPA, 42 U.S.C. § 7410(a)(1), and becomes

federally enforceable once it is approved and adopted by the EPA, 42 U.S.C.

§ 7410(k).

       The Clean Air Act thus provides a cooperative-federalism approach to air

quality regulation. See Fla. Power & Light Co. v. Costle, 650 F.2d 579, 581 (5th

Cir. 1981) (“Congress chose a balanced scheme of state-federal interaction to

implement the goals of the [Clean Air] Act.”).2 Under this approach, states have

“primary responsibility for ensuring that the ambient air meets the NAAQS for the

identified pollutants,” Ky. Res. Council, Inc. v. EPA, 467 F.3d 986, 988 (6th Cir.

2006), and “so long as the ultimate effect of a State’s choice of emission

limitations is compliance with the national standards for ambient air, the State is at

liberty to adopt whatever mix of emission limitations it deems best suited to its

particular situation,” Train v. NRDC, Inc., 421 U.S. 60, 79, 95 S. Ct. 1470, 1482

(1975). “The great flexibility accorded the states under the Clean Air Act is . . .

illustrated by the sharply contrasting, narrow role to be played by the EPA.” Fla.

Power & Light Co., 650 F.2d at 587. If the SIP revision meets the requirements in


       2
          In Bonner v. City of Prichard, 661 F.2d 1206, 1209 (11th Cir. 1981) (en banc), this
Court adopted as binding precedent all decisions of the former Fifth Circuit handed down prior to
close of business on September 30, 1981.

                                               5
the Clean Air Act, the EPA must approve it. See 42 U.S.C. § 7410(k)(3) (“[T]he

Administrator shall approve [a SIP or SIP revision] as a whole if it meets all of the

applicable requirements of this chapter.” (emphasis added)).

      To obtain approval by the EPA, the SIP must comply with the Clean Air Act

requirements set forth at 42 U.S.C. § 7410(a)(2), which mandates, inter alia, the

inclusion of “enforceable emission limitations and other control measures, means,

or techniques . . . as may be necessary or appropriate to meet the applicable [Clean

Air Act] requirements.” 42 U.S.C. § 7410(a)(2)(A); see also Ga. Power, 443 F.3d

at 1348. Once approved, a SIP may not be unilaterally modified by either the state

or the EPA: “no . . . plan revision, or other action modifying any requirement of

an applicable implementation plan may be taken with respect to any stationary

source by the State or by the Administrator [of the EPA].” 42 U.S.C. § 7410(i).

The Clean Air Act does, however, provide cooperative processes for modifying a

SIP that may be initiated by either the EPA or the state.

      A “SIP Call” is one mechanism by which the EPA may initiate a

modification to a SIP. Clean Air Act § 110(k)(5); 42 U.S.C. § 7410(k)(5).

Section 110(k)(5), entitled “[c]alls for plan revisions,” outlines the “SIP Call”

procedure:




                                          6
      Whenever the Administrator finds that the applicable implementation
      plan for any area is substantially inadequate to attain or maintain the
      relevant national ambient air quality standard . . . the Administrator
      shall require the State to revise the plan as necessary to correct such
      inadequacies. The Administrator shall notify the State of the
      inadequacies, and may establish reasonable deadlines (not to exceed
      18 months after the date of such notice) for the submission of such
      plan revisions. Such findings and notice shall be public.

42 U.S.C. § 7410(k)(5). Thus, “whenever” the EPA makes a “substantial

inadequacy” determination, the SIP Call procedure requires the EPA to (1) notify

the state of the substantial inadequacy, and (2) give the state the first opportunity

to revise the SIP to conform with the Clean Air Act. Id.

      Prior to 1990, a SIP Call was the only mechanism by which the EPA could

initiate a modification to a SIP. In 1990, however, Congress added a separate

provision permitting the EPA to initiate a “correction” to a SIP or SIP revision

which had been approved or disapproved “in error.” Clean Air Act § 110(k)(6);

42 U.S.C. § 7410(k)(6). Section 110(k)(6), entitled “[c]orrections,” provides:

      Whenever the Administrator determines that the Administrator’s
      action approving, disapproving, or promulgating any plan or plan
      revision (or part thereof) . . . was in error, the Administrator may in
      the same manner as the approval, disapproval, or promulgation revise
      such action as appropriate without requiring any further submission
      from the State. Such determination and the basis thereof shall be
      provided to the State and public.




                                           7
42 U.S.C. § 7410(k)(6). In contrast to the SIP Call procedure, Section 110(k)(6)

permits the EPA, after determining a prior action approving or disapproving a plan

revision “was in error,” to revise the action without “requiring any further

submission from the State.” Id. Section 110(k)(6) provides a procedure for the

EPA to follow in revising the prior action: the action may be revised “in the same

manner as the approval, disapproval, or promulgation,” and the “determination and

basis thereof shall be provided to the State and public.” Id.

      A state may also voluntarily initiate a revision to its SIP. 42 U.S.C.

§ 7410(a)(1). “If a state wants to add, delete, or otherwise modify any SIP

provision, it must submit the proposed change to EPA for approval.” Sierra Club

v. Tenn. Valley Auth., 430 F.3d 1337, 1346 (11th Cir. 2005) (citing 40 C.F.R.

§ 52.1384). Before adopting and submitting the revision to the EPA, the state

must hold public hearings and accept public comments. 42 U.S.C. § 7410(a);

Tenn. Valley Auth., 430 F.3d at 1348 (citing 40 C.F.R. § 51.102). The EPA “shall

not” approve a SIP revision “if the revision would interfere with any applicable

requirement concerning attainment and reasonable further progress . . . or any

other applicable requirement of [the Clean Air Act].” Clean Air Act § 110(l); 42

U.S.C. § 7410(l).

                     II. Factual and Procedural Background

                                          8
       Under the scheme set forth in the Clean Air Act, Alabama—through the

Alabama Department of Environmental Management (ADEM), and its oversight

body, the Alabama Environmental Management Commission (AEMC)—is the

primary regulator of the state industries’ visible emissions.3 Of relevance here, the

visible emissions portion of Alabama’s SIP regulates opacity, which is “one of the

most basic emission limitations imposed on sources of particulate air pollution.”

Tenn. Valley Auth., 430 F.3d at 1341. Opacity is not a pollutant; rather, it “is a

measure of the light-blocking property of a plant’s emissions, which is important

in the Clean Air Act regulatory scheme as an indicator of the amount of visible

particulate pollution being discharged by a source.” Id. Opacity is thus related to

particulate matter (PM), a regulated pollutant under the Clean Air Act.

       Alabama’s SIP judges compliance with opacity regulations using the EPA

Method 9 test, which is a visual observation by a trained human observer. Ala.

Admin. Code r. 335-3-4-.01(2). As a supplement to the Method 9 test, but not a

replacement, Alabama’s SIP requires certain facilities to operate a continuous

opacity monitoring system (COMS), id. at 335-3-12-.02, which is an electronic



       3
         Alabama’s SIP is codified at 40 C.F.R. § 52.69 and incorporates by reference certain
provisions of ADEM’s Air Pollution Control Program regulations set out at Ala. Admin. Code r.
335-3-1 et seq. ADEM develops SIP regulations, which are approved, disapproved, or modified
by the AEMC. See Ala. Code § 22-22A-8.

                                              9
device that records opacity measurements every six-minutes, as a six-minute

average. A COMS thus produces up to 240 separate readings per day, and these

“[m]ore frequent readings with COMS help determine whether a source is

following good air pollution control practices between Method 9 . . . tests.”

Alabama: Proposed Approval of Revisions to the Visible Emissions Rule, 72 Fed.

Reg. 18,428, 18,431 (April 12, 2007).

      For well over a decade, Alabama’s SIP has prohibited sources from emitting

at levels beyond 20% opacity, as determined by a six-minute average. Ala.

Admin. Code r. 335-3-4-.01(1)(a)(1996). There are exceptions. One exception

permits up to 100% opacity during “startup, shutdown, load change, and rate

change or other short, intermittent periods of time” as approved by ADEM. Id. at

335-3-4-.01(1)(c). Another exception permits up to 40% opacity during one six-

minute period every hour. Id. at 335-3-4-.01(1)(b). In 2003, however, ADEM

sought to broaden the 40% exception to allow sources with COMS to emit “up to

100 percent opacity for up to two percent of the quarterly operating time that they

are otherwise subject to the 20 percent opacity limit.” 72 Fed. Reg. at 18,431.

The EPA’s handling of a subsequent iteration of this proposed revision is the

central issue on appeal.

A.    Alabama’s 2003 Proposed Revision to the Visible Emissions Rule

                                         10
       ADEM formally adopted the proposed revision—also known as the “2% de

minimis rule”—and submitted it to the EPA as a SIP revision in 2003. Tenn.

Valley Auth., 430 F.3d at 1342. The rule provided a safe harbor from the 20%

opacity limitation if “‘[d]uring each calendar quarter . . . the non-exempt excess

emissions periods do not exceed 2.0 percent of the source operating hours for

which the opacity standard is applicable and for which the COMS is indicating

valid data.’” Id. (quoting Ala. Admin. Code r. 335-3-4-.01(4)). Prior to formally

adopting the 2003 proposed revision, ADEM had followed the rule for years in

practice, informally using it “to excuse thousands of opacity violations.” Id. at

1342, 1348.

      While the EPA was reviewing the 2003 proposed revision, this Court issued

a decision in a citizen suit brought against Tennessee Valley Authority (TVA)

using COMS data. Tenn. Valley Auth., 430 F.3d at 1337. We considered whether

the “2% de minimis rule”—which had yet to be approved by the EPA and thus was

not yet part of Alabama’s SIP—applied to alleged opacity violations by TVA

occurring between 1997 and 2002. Id. at 1339. We noted that the rule, followed

only as an informal practice at all times relevant to the suit, was “tantamount to an

unapproved modification of the opacity limitation contained in the Alabama SIP.”

Id. at 1346–47. Because ADEM had attempted “to unilaterally revise the opacity

                                         11
limitation without submitting the revision to the rigors of the SIP amendment

process,” id. at 1348, we held that “ADEM’s practice of employing the 2% de

minimis rule to determine violations of the 20% opacity limitation using COMS

data was invalid under Clean Air Act § 110(i),” id. at 1349.

       Subsequent to our decision in Tennessee Valley Authority, in April 2007,

the EPA concluded that ADEM’s 2003 proposed revision was “not approvable as

submitted.” Alabama: Proposed Approval of Revisions to the Visible Emissions

Rule, 72 Fed. Reg. 18,428, 18,430 (April 12, 2007). The EPA proposed to

approve the revision if ADEM supplemented the request to show that opacity

levels, “averaged” over a quarter of a year, would be at least as stringent as

existing law. Id. at 18,430–31. The EPA notified and provided the public with an

opportunity to comment on the conditional proposal to approve ADEM’s request.

72 Fed. Reg. at 18,434. Citizens provided comments, urging the agency to

disapprove the revision. Comments urging approval were submitted by ADEM,

TVA, and the Utility Air Regulatory Group (UARG).4

B.     The EPA’s 2008 Approval of Alabama’s SIP Revision




       4
         The UARG moved for leave to file an amicus brief in support of Alabama Power and
vacatur of the 2011 disapproval. The UARG’s motion is hereby denied.

                                            12
       ADEM made the revisions requested by the EPA, as well as additional

revisions to address public comments. First, ADEM clarified that the once-per-

hour allowance of up to 40% opacity would not apply to sources using COMS.

Ala. Admin. Code r. 335-3-4-.01(4) (2008).5 Second, for sources using COMS,

ADEM added a cap on daily average opacity of 22%, which was the effective

allowable daily average opacity for those sources under the unrevised rule. Ala.

Admin. Code r. 335-3-4-.01(5) (2008).6 ADEM issued public notice of the

revision, took public comment, and held a public hearing. On August 22, 2008,

AEMC adopted the rule, and ADEM submitted the proposed revision to the EPA

for review.

       On October 15, 2008, the EPA approved ADEM’s revision request. See

Alabama: Approval of Revisions to the Visible Emissions Rule, 73 Fed. Reg.


       5
           Paragraph four describes the exception as follows:

       [D]uring each calendar quarter, the permittee may discharge into the atmosphere
       from any emissions unit qualifying under paragraph (3) of this rule, particulate
       with an opacity exceeding 20% for not more than twenty-four (24), six (6) minute
       periods in any calendar day, if such periods do not exceed 2.0 percent of the
       source calendar quarter operating hours for which the opacity standard is
       applicable and for which the COMS is indicating valid data.

Ala. Admin. Code r. 335-3-4-.01(4) (2008).
       6
          Specifically, paragraph five states: “No permittee shall discharge into the atmosphere
from any source of emission particulate of an opacity greater than 22% (excluding exempt
periods allowed under subparagraphs (1)(c) and (1)(d) of this rule) averaged over each calendar
day.” Ala. Admin. Code r. 335-3-4-.01(5) (2008).

                                                13
60,957 (October 15, 2008). The EPA determined that ADEM had made “the

necessary revisions proposed by EPA” and that the changes were consistent with

the EPA’s recommendations. Id. at 60,957–58. The EPA noted that the

“modeling presented by commenters show[ed] the possibility of an impact on the

NAAQS under a worst-case scenario.” Id. at 60,962. However, the EPA

concluded it lacked “the data necessary to determine quantitatively what impact, if

any, the revisions . . . would or could have on . . . PM emissions,” id., and thus

determined “the proposed SIP revision satisfie[d] the requirements of section

110(l) of the [Clean Air Act],” id. at 60,959.

      The EPA’s approval became final and effective on November 14, 2008. Id.

at 60,957. At that point, the proposed revision became part of the federally

approved Alabama SIP. Sources operating COMS were required to comply with

the revisions “within 6 months of . . . EPA approval.” Ala. Admin. Code r. 335-3-

4-.01(7) (2008). Citizens petitioned the EPA to reconsider its approval, but the

EPA denied the request on January 15, 2009.

C.    Citizens’ Judicial Challenge to the EPA’s 2008 Approval

      On December 12, 2008, Citizens filed a petition in this Court for review of

the EPA’s approval of the SIP revision. Alabama Power, ADEM, and TVA

intervened in support of the EPA’s approval. On February 25, 2009, Citizens filed

                                          14
a second reconsideration request with the EPA. The EPA’s new Acting Regional

Administrator granted the second reconsideration request on April 3, 2009.7

       On April 9, 2009, the EPA moved this Court for a voluntary remand. The

motion noted the Citizens’ second reconsideration request raised “legal, technical

and policy issues that warrant additional review,” and stated the remand would

allow the EPA “to conduct further administrative proceedings and provide an

opportunity for additional public comment on the final rule.” Alabama Power,

ADEM, and TVA opposed the motion, asserting that such reconsideration was

unlawful. The EPA responded and reiterated that it intended to reconsider the

revision “through a public rulemaking process that includes both notice and an

opportunity for comment.” On September 28, 2009, we granted the EPA’s motion

and remanded the case to the EPA “on a limited basis for purposes of

reconsidering the final rule under review.” We also stayed proceedings in the

Court “pending completion of such reconsideration.”

D.     The EPA’s 2011 Disapproval of Alabama’s SIP Revision




       7
         On April 7, 2009, Alabama Power filed a petition for review of the EPA’s decision
granting the second reconsideration request (2009 petition). In our September 28, 2009, order
addressing the EPA’s motion for voluntary remand, we also granted the EPA’s motion to dismiss
the 2009 petition for lack of jurisdiction.

                                             15
      While the proceedings were stayed, on remand, the EPA published a notice

in the Federal Register on October 2, 2009, proposing “to either affirm the

previous rulemaking (which approved the revisions) or, alternatively, amend its

previous rulemaking (i.e., disapproving the revisions).” Alabama: Proposed

Approval of Revisions to the Visible Emissions Rule and Alternative Proposed

Disapproval of Revisions to the Visible Emissions Rule, 74 Fed. Reg. 50,930

(October 2, 2009). The EPA sought “public comment on the nature of the

relationship between opacity and [particulate matter] emissions over both the short

and long term and when the opacity and [particulate matter] mass emissions may

have a predictable relationship to one another (e.g., when an opacity level of a

certain amount would predict a [particulate matter] mass emission of another

certain amount).” 74 Fed. Reg. at 50,934. The EPA provided a 75-day

opportunity for public comment. Citizens and other interested persons submitted

comments urging reversal of the 2008 approval; ADEM, Alabama Power, TVA,

and UARG submitted comments in support of the 2008 approval.

      On April 6, 2011, the EPA published a “Final Rule” disapproving ADEM’s

request to revise the visible emissions portion of Alabama’s SIP. Alabama: Final

Disapproval of Revisions to the Visible Emissions Rule, 76 Fed. Reg. 18,870

(April 6, 2011). The EPA concluded there was “a sufficient likelihood that the

                                         16
SIP revision at issue in this action could allow increased mass emissions over what

would have been allowed under the previously approved SIP rule and that, in the

absence of additional information or limitations, the revision is not approvable

under section 110(l).” 76 Fed. Reg. at 18,876. The EPA noted it would “not have

previously proposed approval if the record clearly demonstrated that the rule

would have resulted in increased [particulate matter] in nonattainment areas.” 76

Fed. Reg. at 18,884. Although the EPA’s 2008 approval was based in part on the

22% average daily opacity cap, following reconsideration, the EPA no longer

accepted “that the average daily opacity limit is an appropriate or effective tool for

evaluating the impact” of the revision on particulate matter emissions. 76 Fed.

Reg. at 18,884. As a result of the EPA’s disapproval, “Alabama’s visible

emissions rule that was in the SIP prior to the October 15, 2008, final action

[became] the current SIP-approved rule.” 76 Fed. Reg. at 18,870.

E.    Consolidation of the 2008 and 2011 Petitions

      On April 8, 2011, Alabama Power filed a petition in this Court for review of

the EPA’s 2011 disapproval of the SIP revision. Citizens intervened in support of

the EPA’s disapproval. Alabama Power moved to consolidate Citizens’ 2008

petition with Alabama Power’s 2011 petition, and to stay the EPA’s disapproval

pending appeal. Citizens moved to stay their 2008 petition pending resolution of

                                          17
Alabama Power’s 2011 petition. On May 12, 2011, we denied both motions to

stay but granted Alabama Power’s motion to consolidate the 2008 and 2011

petitions, treating the competing petitions as cross-appeals under Federal Rule of

Appellate Procedure 28.1.

                               III. Standard of Review

      Both petitions for review of the EPA’s actions are brought pursuant to 42

U.S.C. § 7607(b)(1). We apply “the deferential standard of review set forth in the

Administrative Procedure Act.” Sierra Club v. Johnson, 436 F.3d 1269, 1273

(11th Cir. 2006). Under this standard, a final agency action will be set aside if it is

“arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with

law”; exceeds the agency’s statutory authority; or is “without observance of

procedure required by law.” 5 U.S.C. § 706(2)(A), (C), & (D). “Under this

standard, we give deference to a final agency decision by reviewing for clear error,

and we cannot substitute our own judgment for that of the agency.” Johnson, 436

F.3d at 1273.

      A challenge to the EPA’s interpretation of the Clean Air Act is governed by

the two-step analysis in Chevron U.S.A., Inc. v. NRDC, Inc., 467 U.S. 837,

842–45, 104 S. Ct. 2778, 2781–83 (1984). First, we determine “whether Congress

has directly spoken to the precise question at issue.” Chevron, 467 U.S. at 842,

                                          18
104 S. Ct. at 2781. If Congress’s intent is clear from the statutory language, we

must “give effect to the unambiguously expressed intent of Congress.” Id. at 843,

104 S. Ct. at 2781. Second, if Congress has not spoken and the statute is “silent or

ambiguous with respect to the specific issue, the question for the court is whether

the agency’s answer is based on a permissible construction of the statute.” Id. at

843, 104 S. Ct. at 2782.

                                  IV. Discussion

      We are presented with challenges to both the 2008 approval and the 2011

disapproval in this consolidated appeal. We begin with the 2011 disapproval and

consider whether the EPA complied with the statutory procedures set forth in the

Clean Air Act. Because the EPA failed to make the statutorily required error

determination, we conclude the 2011 disapproval was not authorized by the Clean

Air Act. We also conclude the EPA’s 2011 disapproval was not authorized by

either its inherent authority or by this Court, and must therefore be vacated. We

then address and dismiss challenges to the 2008 approval, and affirm the validity

of that action.

A.    The EPA’s 2011 Disapproval of Alabama’s SIP Revision

      Alabama Power contends the EPA’s 2011 disapproval was unauthorized by

law because the SIP Call procedure outlined in Section 110(k)(5) of the Clean Air

                                         19
Act was the only process by which the EPA could revise Alabama’s SIP. The

EPA claims the 2011 disapproval was authorized by Section 110(k)(6) of the

Clean Air Act because the EPA erroneously approved the SIP revision in 2008.

Additionally, the EPA claims the 2011 disapproval was authorized by its inherent

authority and by this Court’s September 28, 2009, remand order.8

       1. Whether the Clean Air Act Authorized the EPA’s 2011 Disapproval

       We first reject Alabama Power’s contention that the SIP Call process

outlined in Section 110(k)(5) was the exclusive procedure by which the EPA

could revise Alabama’s SIP.9 As discussed previously, “[w]henever the

       8
          The EPA also contends Section 553(e) of the Administrative Procedure Act (APA),
which gives “an interested person the right to petition for the issuance, amendment, or repeal of a
rule,” authorized the 2011 disapproval. 5 U.S.C. § 553(e). While Section 553(e) authorized
Citizens to petition for repeal of the 2008 approval, that provision does not displace the
procedural requirements of the Clean Air Act for SIP revisions and error corrections. See 5
U.S.C. § 559 (stating the APA does “not limit or repeal additional requirements imposed by
statute or otherwise recognized by law”). Thus, we must still consider whether the EPA’s 2011
disapproval complied with the procedures set forth in the Clean Air Act.
       9
          For this contention, Alabama Power cites language from this Court’s decision in
Georgia Power, a citizen enforcement action in which we rejected Sierra Club’s argument that a
1999 Guidance Policy issued by the EPA had the effect of revising Georgia’s SIP. 443 F.3d at
1354. We stated that “even if the EPA had intended its 1999 policy to alter the meaning of
Georgia’s existing” SIP, “the EPA would have been powerless to effect such a change absent
formal SIP revision.” Id. Citing the SIP Call provision, we noted that “[i]f the EPA believes that
its current interpretation of the Clean Air Act requires Georgia to modify its [SIP], the EPA
should require the state to revise its SIP to conform to EPA policy.” Id. at 1355. Although
Alabama Power contends Georgia Power established the SIP Call procedure as the exclusive
procedure by which the EPA may reverse its initial approval, the cited language was in the
context of analyzing Sierra Club’s argument that an EPA policy document effected a change to a
SIP. Moreover, the EPA itself stated that the Georgia SIP remained in effect regardless of the
1999 Guidance policy. Id. at 1354 n.12.

                                                20
Administrator finds [the SIP] substantially inadequate,” Section 110(k)(5) requires

the EPA to notify the state of the substantial inadequacy, and then give the state

the first opportunity to revise the SIP to conform with the Clean Air Act. 42

U.S.C. § 7410(k)(5). While Section 110(k)(5) provides an avenue for revising a

substantially inadequate SIP, Section 110(k)(6) provides an avenue for correcting

a SIP revision approved in error. Here, the EPA does not contend Alabama’s SIP

was “substantially inadequate”; rather, the EPA is claiming it made an “error” in

2008 when it initially approved the SIP revision. Thus, for our purposes, the

lawfulness of the 2011 disapproval hinges on whether Section 110(k)(6)

authorized the EPA’s action.

      Section 110(k)(6) permits the EPA to “revise” a SIP provision approved “in

error” without “any further submission from the State.” 42 U.S.C. § 7410(k)(6).

Section 110(k)(6) “may” be invoked “[w]henever the Administrator determines

that the Administrator’s action approving, disapproving, or promulgating any plan

or plan revision (or part thereof) . . . was in error.” Id. The statute provides the

procedure for correcting or “revis[ing]” the erroneous action: “the Administrator

may in the same manner as the approval, disapproval, or promulgation revise such

action as appropriate without requiring any further submission from the State.” Id.




                                          21
The statute requires that “[s]uch determination and the basis thereof shall be

provided to the State and public.” Id.

      As the plain language shows, Section 110(k)(6) has both discretionary and

mandatory features. Through the use of the terms “whenever” and “may,” Section

110(k)(6) confers discretion on the EPA to decide if and when it will invoke the

statute to revise a prior action. See, e.g., N.Y. Pub. Interest Research Grp. v.

Whitman, 321 F.3d 316, 330–31 (2d Cir. 2003) (stating that the phrase

“[w]henever the Administrator makes a determination” in Section 502(i)(1) of the

Clean Air Act grants the EPA “discretion whether to make a determination”). To

invoke Section 110(k)(6), however, the plain language of the statute requires a

determination by the Administrator that “the action approving . . . [the] plan

revision . . . was in error.” 42 U.S.C. § 7410(k)(6); see also Chevron, 467 U.S. at

843, 104 S. Ct. at 2781 (noting the court must “give effect to the unambiguously

expressed intent of Congress”). Our conclusion that the error determination is

mandatory to invoke Section 110(k)(6)’s procedure is based on the last provision

of the statute, which, using mandatory “shall” language, requires that the EPA

provide “the State and public” with its error “determination and the basis thereof.”

42 U.S.C. § 7410(k)(6). Thus, if the EPA chooses to invoke Section 110(k)(6) to




                                          22
revise a prior action, Congress has required the EPA to articulate an “error” and

provide “the basis” of its determination that an error occurred.

      Here, the EPA has been unable to point to a determination of the error

committed in the 2008 approval. Neither the text of the final rule disapproving the

revision published in the Federal Register, nor the record before this Court, reveal

that the EPA affirmatively made the requisite error determination. See Motor

Vehicle Mfrs. Ass’n of the U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 463 U.S.

29, 50, 103 S. Ct. 2856, 2870 (1983) (“[A]n agency’s action must be upheld, if at

all, on the basis articulated by the agency itself.”). Section 110(k)(6) is only

referred to in passing in the final rule, when the “EPA notes that the process it has

used for reconsidering and disapproving this SIP revision is entirely consistent

with the process required under [S]ection 110(k)(6).” 76 Fed. Reg. at 18,878 n.18.

Nowhere in the final rule does the EPA clearly articulate the alleged “error”

committed in 2008 at the time of the initial approval. See generally 76 Fed. Reg.

18,870. We decline to speculate as to the error “determination and the basis

thereof” when the EPA itself has failed to provide a cognizable error

determination. See Investacorp, Inc. v. Arabian Inv. Banking Corp. (Investcorp)

E.C., 931 F.2d 1519, 1524 (11th Cir. 1991) (“Although we will bestow proper

respect to the determinations of the [agency], we will not defer to an ethereal

                                          23
determination that is not affirmatively stated by the administrative agency.”); see

also Mitchell Energy Corp. v. FERC, 651 F.2d 414, 418 (5th Cir. 1981) (“If the

administrative action is to be tested by the basis upon which it purports to rest, that

basis must be set forth with such clarity as to be understandable. It will not do for

a court to be compelled to guess at the theory underlying the agency’s action; nor

can a court be expected to chisel that which must be precise from what the agency

has left vague and indecisive.” (quoting SEC v. Chenery Corp., 332 U.S. 194,

196–97, 67 S. Ct. 1575, 1577 (1947)). As such, the EPA has not complied with

the procedural demands Congress articulated in Section 110(k)(6).10

       Moreover, the EPA has failed to clarify the ambiguity surrounding the error

committed in the 2008 approval despite opportunities to do so.11 Although the

EPA’s brief relies on Section 110(k)(6) as authority for the 2011 “error

correction,” the brief fails to provide a clear statement of the error committed in

the 2008 approval. In an effort to understand the EPA’s assertion of error, we



       10
          Although the dissent concludes the EPA’s 2011 interpretation of Section 110(l) was
substantively permissible, we do not reach this issue because the EPA failed to follow the Clean
Air Act’s mandate to provide “the State and public” with its error “determination and the basis
thereof.” 42 U.S.C. § 7410(k)(6).
       11
           We note that we are reluctant to accept litigation positions as official justifications for
agency action. See, e.g., Gonzalez v. Reno, 212 F.3d 1338, 1350 (11th Cir. 2000) (“An after-the-
fact rationalization of agency action—an explanation developed for the sole purpose of defending
in court the agency’s acts—is usually entitled to no deference from the courts.”).

                                                 24
focused on this issue at oral argument. However, when questioned as to where we

would find a statement in the record from the EPA regarding the error committed

in the 2008 approval, counsel for the EPA stated “[y]ou are not going to find it in

the Federal Register notice.” Rather, counsel directed us to the EPA’s 2009

motion for voluntary remand, which stated “the agency has determined that its

prior action may have been in error or inadequately explained.”

       A statement in a motion for voluntary remand that there “may have been”

error is insufficient to invoke Section 110(k)(6) as authority to revise a SIP.

Section 110(k)(6) requires that the “determination and the basis thereof shall be

provided to the State and public,” such that the mere possibility of error is

inadequate. Here, we are simply unable to locate the statutorily required error

determination in the record so that we may evaluate whether the EPA’s application

of Section 110(k)(6) was appropriate. The EPA itself cannot point to the error

committed in the 2008 approval; we are not permitted to rummage through the

record and cobble one together for them.12 See Bowman Transp., Inc. v. Arkansas-

       12
            Although the dissent infers error from a combination of EPA comments, we decline to
do so. At most, the EPA’s statements in the record indicate that its 2008 findings were
comparatively less strong than its 2011 findings, based on a different interpretation of Section
110(1). If we conclude this combination of EPA record statements constitutes an error
determination under Section 110(k)(6), it is hard to imagine any statement by the EPA that would
not qualify so long as the EPA argues, as it did here, that its prior findings could have been
better. If the EPA would like to affirmatively declare the 2008 approach erroneous, our opinion
leaves it free to do so, so long as it follows Congress’s statutory procedures.

                                              25
Best Freight Sys., Inc., 419 U.S. 281, 285–86, 95 S. Ct. 438, 442 (1974) (noting

that under the APA standard of review, courts may not supply “a reasoned basis

for the agency’s action that the agency itself has not given”); see also Camp v.

Pitts, 411 U.S. 138, 142, 93 S. Ct. 1241, 1244 (1973) (stating that under the APA

standard of review, “the focal point for judicial review should be the

administrative record already in existence”).

      The EPA is fully capable of articulating an error when proceeding under

Section 110(k)(6). For example, in a Federal Register notice issued one month

after the final rule at issue here, the EPA invoked Section 110(k)(6) for authority

to correct its previous full approval of Texas’s Clean Air Act Prevention of

Significant Deterioration (PSD) program. Determinations Concerning Need for

Error Correction, Partial Approval and Partial Disapproval, and Federal

Implementation Plan Regarding Texas’s Prevention of Significant Deterioration

Program, 76 Fed. Reg. 25,178 (May 3, 2011). The EPA explicitly articulated the

error committed at the time of the prior action: “[The] EPA is determining in this

rulemaking that it erred in fully approving Texas’s PSD program in 1992 because

at that time, the program had a gap, which recent statements by Texas have made

particularly evident.” 76 Fed. Reg. at 25,179. The EPA then took action “through




                                         26
the error-correction mechanism provided under” Section 110(k)(6) to correct the

1992 error, revising its previous full approval to a partial disapproval. Id.13

       Here, as the EPA conceded at oral argument, there is no such explicit error

determination in the Federal Register notice for the SIP revision at issue. We are


       13
            The EPA’s clear invocation of Section 110(k)(6) in the 2011 correction of Texas’s
PSD program is not an outlier. In fact, articulating an error to invoke Section 110(k)(6) appears
to have been the EPA’s consistent practice and interpretation of Congress’s procedural
requirements for at least 15 years. See Limitation of Approval of Prevention of Significant
Deterioration Provisions Concerning Greenhouse Gas Emitting-Sources in State Implementation
Plans; Final Rule, 75 Fed. Reg. 82,536, 82,543–45 (Dec. 30, 2010) (identifying errors clearly and
specifically invoking the error correction method of Section 110(k)(6)); Approval and
Promulgation of Implementation Plans; Kentucky: Approval of Revisions to the State
Implementation Plan, 75 Fed. Reg. 2,440, 2,440–41 (January 15, 2010) (“EPA has determined
that [the state’s] rule . . . was erroneously incorporated into the SIP because the rule is not related
to the attainment and maintenance of the national ambient air quality standards.”); see also id. at
2441 (specifying clearly that it was “removing” a previously approved rule “pursuant to section
110(k)(6) of the Clean Air Act” in order to “correct[]” its “error”); id. at 2443 (explaining that
the rule being deleted “was erroneously incorporated into the SIP because it does not relate to the
implementation, maintenance, and enforcement of the NAAQS in Kentucky”); Designation of
Areas for Air Quality Planning Purposes; Arizona; Correction of Boundary of Phoenix
Metropolitan 1-Hour Ozone Nonattainment Area, 70 Fed. Reg. 68,339, 68,339 (November 10,
2005) (declaring that the “EPA is taking direct final action to correct” its prior determination
“under the authority of section 110(k)(6) of the Clean Air Act”); see also id. at 68,343 (“Based
on the historic ambient monitoring data and prevailing wind patterns in the area, we conclude
that we clearly erred in failing to consider data made available at the time of our September 1979
affirmation . . . .”); id. (concluding that based on overlooked data, the agency’s prior boundary
determination “was erroneous”); id. at 68,345 (stating that the agency’s action was intended to
“remov[e] unnecessary obligations that flow[ed] from the erroneous inclusion” of a portion of
land in the EPA’s boundary determination); Designation of Areas for Air Quality Planning
Purposes; Correction of Designation of Nonclassified Ozone Nonattainment Areas; States of
Maine and New Hampshire, 62 Fed. Reg. 14,641, 14,641 (March 27, 1997) (announcing the
EPA’s “decision to correct” its prior ozone designations “pursuant to section 110(k)(6) of the
Clean Air Act (the Act), which allows the USEPA to correct its actions”); see also id. at 14,642
(concluding that its “earlier action . . . was in error,” because the “information submitted by [the
state] did not provide enough data” to make the designation); id. (declaring itself to be
“correcting [an] error” based on “clearly inadequate” “information available at the time of the
designation”).

                                                  27
not holding that “magic words” are required to invoke Section 110(k)(6). But,

Congress has demanded, at a minimum, that the EPA affirmatively articulate the

error committed at the time of the initial action if it chooses to rely on its Section

110(k)(6) authority to later revise that action.14

       To recap, the Clean Air Act contains two provisions that grant the EPA

authority to revise a SIP: Sections 110(k)(5) and (k)(6). 42 U.S.C. §§ 7410(k)(5)

& (6). The EPA does not purport to rely on the SIP Call procedures set forth in

Section 110(k)(5), nor could it, as there was never a finding of substantial

inadequacy. 42 U.S.C. § 7410(k)(5). Although the EPA does purport to rely on

the error-correction mechanism provided in Section 110(k)(6), the EPA did not

“provide[] . . . the State and public” with the error determination Congress

requires. 42 U.S.C. § 7410(k)(6). Thus, we conclude the EPA did not act in

accordance with the Clean Air Act in the 2011 disapproval of Alabama’s visible

emissions SIP revision.



       14
           The dissent’s approach of inferring error where such error has not been affirmatively
articulated by the EPA would limit the EPA’s future ability to change policies. As the dissent
points out, it is not “unusual for a change in philosophy within an agency to result in a policy
about-face.” However, a change in policy does not in and of itself indicate that the prior
enforcement policy was erroneous, as there can be multiple permissible agency interpretations of
a statute. Chevron, 467 U.S. at 843 n.11, 104 S. Ct. at 2782 n.11. It is at least feasible that a
change in administration would result in the EPA applying a 2008-type approach to Section
110(l)’s enforcement, and to declare this approach erroneous, without the EPA having done so
itself, would limit the EPA’s future enforcement flexibility.

                                               28
      2. Whether the EPA Acted Within its Inherent Authority in Issuing the 2011
         Disapproval

      As additional justification for the 2011 disapproval, the EPA contends it

was acting within its inherent authority to reconsider decisions. 76 Fed. Reg. at

18,877–78. The EPA relies on Gun South, Inc. v. Brady, 877 F.2d 858 (11th Cir.

1989), and New Jersey v. EPA, 517 F.3d 574 (D.C. Cir. 2008), as support for its

claim of inherent authority. We conclude the EPA cannot rely on any inherent

authority here, where Congress has provided specific statutory procedures for

revising a SIP. See 42 U.S.C. § 7410(k)(5), (k)(6).

      Gun South considered the authority of the Bureau of Alcohol, Tobacco, and

Firearms (Bureau) to temporarily suspend the importation of assault rifles under

the Gun Control Act. Gun S., 877 F.2d at 860–61. After noting neither the Gun

Control Act nor its implementing regulations expressly authorized the suspension,

we concluded “the Bureau must necessarily retain the power to correct the

erroneous approval of firearms import applications,” as well as “the corollary

power to temporarily suspend the importation of firearms.” Id. at 862. As support

for our conclusion that the temporary suspension fell within the Bureau’s implied

authority, we recognized the general rule that agencies possess implied authority

“to reconsider and rectify errors even though the applicable statute and regulations



                                         29
do not expressly provide for such reconsideration.” Id. Thus, Gun South

recognized the Bureau’s implied authority to impose a temporary suspension

where the Gun Control Act lacked an express provision authorizing such action.

Id.15

        In contrast to the Bureau in Gun South, here, the EPA had statutory tools

available to revise the SIP: Sections 110(k)(5) and (k)(6) of the Clean Air Act.

The EPA chose to invoke Section 110(k)(6) of the Clean Air Act to “revise” a SIP

revision approved “in error,” 47 U.S.C. § 7410(k)(6), but failed to articulate what

error was committed in the 2008 approval. We decline to imply any authority to

act beyond the confines of the EPA’s statutory authority where the Clean Air Act

provides express provisions for revising and correcting a SIP. See, e.g., Mich. v.

EPA, 268 F.3d 1075, 1081 (D.C. Cir. 2001) (noting the EPA is “a creature of

statute,” and may exercise “only those authorities conferred upon it by Congress”).

        We note that our conclusion is consistent with New Jersey, 517 F.3d at 582,

where the D.C. Circuit recognized that “[a]n agency can normally change its

position and reverse a decision.” The D.C. Circuit noted an important

        15
           As support for our finding of implied authority, we also relied on the legislative history
in the Gun Control Act illustrating “Congress’s intent absolutely to bar the importation of
firearms outside of the narrow statutory exceptions.” Gun S., 877 F.2d at 862. Additionally, we
noted the Bureau did not interpret the Gun Control Act as prohibiting a temporary ban, and
deferred to the Bureau’s interpretation because the plain language of the statute did not compel a
different interpretation. Id. at 863.

                                                 30
qualification on that general principle: “Congress, however, undoubtedly can

limit an agency’s discretion to reverse itself.” Id. at 583. In New Jersey, the court

held Congress did just that by including express delisting requirements in the

Clean Air Act. Id. The D.C. Circuit concluded those express provisions

precluded the EPA from claiming it possessed inherent authority to delist a

regulated unit without following the statutory procedure. See id. (noting that

“when Congress has provided a mechanism capable of rectifying mistaken actions

. . . it is not reasonable to infer authority to reconsider agency action” (internal

quotation marks omitted)). Likewise, the Clean Air Act’s express statutory

provisions for revising and correcting a SIP preclude the EPA’s reliance on any

claim of inherent authority here.

      3. Whether the 2011 Disapproval was Court-Authorized

      As a final source of authority, the EPA places great weight on this Court’s

September 28, 2009, order granting its motion for voluntary remand. The EPA

relies on the “memoranda filed by the parties” to define “[t]he scope of

authorization [the] EPA received from the Court,” and contends “[c]ontext and

logic underscore that [the] EPA obtained authorization from this Court to proceed

as it did on remand.” We disagree with this bold assertion.




                                           31
      On April 9, 2009, the EPA moved this Court for a voluntary remand. Our

September 28, 2009, order granting the motion provided as follows:

      The EPA has filed a “Motion for Voluntary Remand” in Appeal No.
      08-16961, which is a petition for review of the final rule approving
      revisions to the Alabama State Implementation Plan. The “Motion
      for Voluntary Remand,” construed as a motion for limited remand to
      permit the EPA to conduct reconsideration proceedings and to stay
      this Court’s proceedings pending resolution of reconsideration, is
      GRANTED. Appeal Number 08-16961 is hereby REMANDED to
      the EPA on a limited basis for purposes of reconsidering the final rule
      under review, and proceedings in this Court shall remain STAYED
      pending completion of such reconsideration. The EPA is directed to
      provide the Court with reports every sixty (60) days regarding the
      status of the reconsideration proceedings.

September 28, 2009, Order Granting Motion for Voluntary Remand at 2–3.

Nothing in the order explicitly authorized the EPA to act outside the statutory

procedures set forth in the Clean Air Act. The order simply permitted the EPA to

conduct reconsideration proceedings on remand, and stayed the appeal pending

completion of such reconsideration.

      We decline the EPA’s invitation to imply rulings on substantive issues from

this seemingly straightforward remand order. Even assuming we could divine

“court authorization” for the 2011 disapproval from this order, the order has no

precedential value. Our rules state that “[a] ruling on a motion or other

interlocutory matter, whether entered by a single judge or a panel, is not binding



                                         32
upon the panel to which the appeal is assigned on the merits, and the merits panel

may alter, amend, or vacate it.” 11th Cir. R. 27-1(g). Accordingly, we reject the

EPA’s “court authorization” argument as meritless.

      4. The 2011 Disapproval is Vacated

      In sum, because the 2011 disapproval was not conducted according to the

statutory procedures set forth in the Clean Air Act, we must set it aside. See 5

U.S.C. § 706(2)(C),(D) (stating a final agency action must be set aside if it

exceeds the agency’s statutory authority or is “without observance of procedure

required by law”). We therefore grant Alabama Power’s petition challenging the

2011 disapproval and vacate the EPA’s final disapproval of revisions to

Alabama’s visible emissions rule. Because the April 6, 2011, final rule is vacated,

the October 15, 2008, final rule approving the revisions stands as the last final

action taken on the proposed revision. Thus, we must next consider Citizens’

petition challenging the October 15, 2008, final rule.

B.    The EPA’s 2008 Approval of Alabama’s SIP Revision

      Citizens contend the 2008 approval violates Section 110(l) of the Clean Air

Act. Citizens make no specific argument as to how the EPA’s 2008 approval

violated Section 110(l) of the Clean Air Act; rather, they rely on their arguments

as to how the EPA’s 2011 disapproval did not violate the Clean Air Act. Citizens

                                         33
also challenge two long-standing provisions of Alabama’s SIP that were not a part

of Alabama’s 2008 submissions.16 The EPA does not defend the 2008 approval,

but Alabama Power, as an intervenor in the 2008 appeal, claims the 2008 approval

was valid and lawful.

       1.      Whether the 2008 Approval Violates Section 110(l) of the Clean Air
               Act

       Section 110(l) of the Clean Air Act, entitled “Plan revisions,” provides in

pertinent part that “[t]he Administrator shall not approve a revision of a plan if the

revision would interfere with any applicable requirement concerning attainment

and reasonable further progress . . . or any other applicable requirement of this

Act.” 42 U.S.C. § 7410(l). The question of whether the 2008 approval violates

the Clean Air Act depends on the meaning of the phrase “would interfere.” The

Sixth Circuit has concluded that “[a] court searching for the meaning of ‘interfere’

[in Section 110(l)] or for a clearly preferred mechanism for determining that which

interferes wades into ambiguity, the only solution to which is the deferential

Chevron step two.” Ky. Res. Council, 467 F.3d at 995. We agree, as the Clean Air

Act “does not directly speak to how a determination of interference is to be made.”


       16
           Citizens also make a vague and general assertion that the proposed revision leaves
Alabama incapable of detecting particulate matter violations. Citizens have failed to offer any
support for this claim, and there is no indication that the SIP revision renders Alabama incapable
of detecting violations and enforcing the visible emissions limits.

                                                34
Id. (internal quotation marks omitted). Thus, under Chevron step two, we defer to

the EPA’s interpretation of Section 110(l) if it is based on a permissible

construction of the statute. Chevron, 467 U.S. at 842–43.

      In the 2008 approval, the EPA interpreted Section 110(l) to permit approval

of the SIP revision “‘unless the agency finds it will make air quality worse.’” 73

Fed. Reg. at 60,960 (quoting Ky. Res. Council, 467 F.3d at 995). The EPA then

concluded the proposed SIP revision satisfied Section 110(l)’s requirements

because the revision would not interfere with either the annual or 24-hour

particulate matter NAAQS. 73 Fed. Reg. at 60,959.

      The EPA’s interpretation is a permissible reading of Section 110(1), and thus

entitled to deference. The Sixth Circuit reached this same conclusion in Kentucky

Resources Council, 467 F.3d at 996, and we find its reasoning persuasive. As the

Sixth Circuit noted, the EPA’s interpretation gives the states flexibility and “does

service to a fundamental premise underlying the Clean Air Act scheme, which is

that the states have the primary responsibility for ensuring that the NAAQS are

met.” Id.

      We agree that where interference is not demonstrated, approval of the state’s

SIP revision appropriately respects the state’s choice to achieve air quality

standards with “whatever mix of emission limitations it deems best suited to its

                                          35
particular situation.” Train, 421 U.S. at 79, 95 S. Ct. at 1482; see also Fla. Power

& Light Co., 650 F.2d at 581 (“The state is ‘at liberty’ to devise the particular

components of its pollution control plan so long as the plan is adequate to meet the

standards mandated by [the] EPA.”). Because we find the EPA’s interpretation

reasonable and entitled to deference, the EPA’s 2008 approval utilizing that

interpretation does not violate Section 110(1) of the Clean Air Act.

      Although we conclude the EPA’s interpretation of Section 110(1) in the

2008 approval was permissible, we pass no judgment on the EPA’s interpretation

of Section 110(1) in the 2011 disapproval. There may be more than one

permissible interpretation of a statute, see Chevron, 467 U.S. at 843 n.11, 104 S.

Ct. at 2782 n.11, and so long as the interpretation is permissible, it does not matter

whether the interpretation “is a dramatic shift in EPA policy,” Friends of

Everglades v. S. Fla. Water Mgmt. Dist., 570 F.3d 1210, 1219 (11th Cir. 2009).

      2.     Whether the Automatic Exemption and Director’s Discretion
             Provisions Violate the Clean Air Act

      Citizens contend the rule providing automatic exemptions for “startup,

shutdown, load change, and rate change or other short, intermittent periods of

time,” see Ala. Admin. Code r. 335-3-4-.01(1)(c), may not be approved as part of

Alabama’s SIP because such a rule would prevent the limitations of emissions on a



                                          36
continuous basis. Citizens also claim the SIP’s “director’s discretion” provisions,

see Ala. Admin. Code r. 335-3-4-.01(1)(d), are prohibited by the Clean Air Act

because such provisions give the state the power to change rules unilaterally.

       Citizens’ attempt to challenge the EPA’s approval of the automatic

exemption and director’s discretion provisions is untimely. Section 7607(b)(1)

requires that “[a]ny petition for review under this subsection shall be filed within

sixty days from the date notice of such promulgation, approval, or action appears in

the Federal Register.” 42 U.S.C. § 7607(b)(1). The automatic exemption for

“startup, shutdown, load change, and rate change or other short, intermittent

periods of time,” Ala. Admin. Code r. 335-3-4-.01(1)(c), became an approved part

of Alabama’s SIP in 1972. See Approval and Promulgation of Implementation

Plans, 37 Fed. Reg 10,842, 10,847–48 (May 31, 1972). The “director’s discretion”

provision, Ala. Admin. Code r. 335-3-4-.01(1)(d), became an approved part of

Alabama’s SIP in 1993. See Alabama: Approval of the Visible Emission

Regulations, 58 Fed. Reg. 25,566 (April 27, 1993). Accordingly, Citizens’ attempt

to challenge these provisions now is untimely. 42 U.S.C. § 7606(b)(1).

      Moreover, we reject Citizens’ contention that the EPA reopened these

provisions for review by considering the 2008 SIP revision. The EPA made clear

from the outset that “[t]he director’s discretion provisions under Alabama rule 335-

                                          37
3-4.01(1)(c) and (d) would be unchanged by [the 2008] SIP revision,” and that the

provisions were “not being revised by ADEM or reviewed by [the] EPA at

present.” 73 Fed. Reg. at 60,958 n.1. The EPA also stated that “nothing in [the

Federal Register] notice should be considered as approving those provisions.” Id.

There is no support for the Citizens’ contention that the EPA reopened these issues.

      We also reject Citizens’ claim that the EPA “constructively” reopened the

provisions by considering the 2008 SIP revision. Citizens rely on Sierra Club v.

EPA, 551 F.3d 1019 (D.C. Cir. 2008), in which the D.C. Circuit stated a

“constructive reopening occurs if the revision of accompanying regulations

‘significantly alters the stakes of judicial review.’” Id. at 1025 (quoting Kennecott

Utah Copper Corp. v. U.S. Dep’t of Interior, 88 F.3d 1191, 1227 (D.C. Cir. 1996)).

The D.C. Circuit concluded the EPA had constructively reopened a startups,

shutdowns, and malfunctions (SSM) exemption by “completely chang[ing] the

regulatory context for its SSM exemption by stripping out virtually all of the SSM

plan requirements that it created to contain the exemption.” Id. (internal quotation

marks omitted) (emphasis omitted).

      Prior to the rulemakings at issue in Sierra Club, the EPA had limited the

SSM exemption by (1) requiring sources to comply with an SSM plan during

periods of SSM, (2) requiring review and approval of the SSM plan, (3) requiring

                                          38
that the SSM plans be made available to the public, such that the public could

participate in the permit approval process, and (4) making the SSM plan directly

enforceable. Id. at 1025. In the rulemakings challenged by Sierra Club, however,

the EPA—while not officially reopening the SSM exemption—eliminated all of the

aforementioned safeguards, meaning the SSM plans were no longer mandatory,

enforceable, subject to approval, or publicly available. Id. at 1025–26.

      We are not presented with an analogous situation. Citizens have not pointed

to any changes, minor or major, to the automatic exemption for “startup, shutdown,

load change, and rate change or other short, intermittent periods of time,” or to the

“director’s discretion” provisions. Citizens have also failed to demonstrate that the

EPA has created a new regulatory context sufficient to constructively reopen the

provisions—there is simply no evidence the provisions, or the enforcement of the

provisions have changed in any way. Because the EPA did not reopen these

provisions, constructively or otherwise, we decline to review them on appeal.

      Accordingly, we deny Citizens’ petition challenging the 2008 approval and

affirm the EPA’s final rule approving revisions to Alabama’s visible emissions

rule. 73 Fed. Reg. at 60,957. As a final matter, we decline to follow Citizens’ and

the EPA’s suggestion that we ignore the 2008 approval. If the EPA wishes to




                                          39
revise or correct the 2008 approval, it may do so by following the statutory

procedures provided in the Clean Air Act. See 42 U.S.C. §§ 7410(k)(5), (k)(6).

                                      V. Conclusion

       Alabama Power’s petition is hereby GRANTED, and the EPA’s 2011

disapproval is VACATED.17 Citizens’ petition is hereby DENIED, and the EPA’s

2008 approval is AFFIRMED.




       17
          On June 21, 2011, Alabama Power filed a motion to direct the EPA to supplement the
administrative record. The motion is denied.

                                             40
MOLLOY, District Judge, concurring in part and dissenting in part:

      I agree with much of the Court’s opinion, including its determination that the

EPA was not required to issue a SIP call as the exclusive means of revising the SIP

approved in 2008. To that extent, I concur in the majority opinion. But I respectfully

dissent from the Court’s determination that “[n]either the text of the final rule

disapproving revision published in the Federal Register, nor the record before this

Court, reveal that EPA affirmatively made the requisite error determination.” Majority

Op. at 23.

      My disagreement is based on two specific differences with the Court’s opinion.

First, the EPA’s notices and decisions in the Federal Register quite clearly describe

how the agency believes it was in error in approving the 2008 proposed revision.

Second, the process that the EPA followed was more accommodating to the State and

to the affected industries than what will inevitably follow from Court’s decision, as

applied in future cases. I believe we should dismiss the 2008 action for lack of

jurisdiction and affirm the EPA’s 2011 disapproval.

                                         I.

      When the EPA published notice that it was proposing either to affirm its

approval or disapprove Alabama’s proposed revision, it said:




                                         41
      EPA’s prior approval notice provides extensive discussion of the reasons
      why EPA concluded in that notice that section 110(l) had been satisfied.
      In particular, EPA stated as grounds for this conclusion that: “(1) The
      revision would not increase the allowable average opacity levels; and (2)
      the relationship between changes in opacity and increases or decreases
      in ambient PM2.5 levels cannot be quantified readily for the sources
      subject to this SIP revision, and is particularly uncertain for short-term
      analyses.”


74 Fed. Reg. 50930, 50932–33 (Oct. 2, 2009) (quoting 73 Fed. Reg. at 60959 (Oct. 15,

2008)) (internal citations and footnote omitted).

      Given those two reasons for approving the 2008 proposed revision, the error

that the EPA believes it committed is identified in the thorough description set forth

in the Federal Register:

      Based on the information received to date, EPA believes that increases
      or decreases in PM2.5 emissions based on short-term increases in opacity
      cannot be quantified readily for the sources subject to this SIP revision.
      There are several contributors to the uncertainties associated with
      relating mass emissions to increases in opacity, including: (1)
      Differences between combustion technology characteristics and fuel
      components, (2) differences in control technology types, temperatures at
      which they operate, and load characteristics, (3) the recognition that both
      opacity and mass emissions are subject to significant variability over
      short periods of time and fluctuations such that one may act
      independently of the other, and (4) differences between the mass of
      particles that exists at the point of opacity measurement by the COMS
      (e.g., in the stack) and the direct PM2.5 that forms immediately upon
      exiting the stack (that are related to fuel components more than to control
      technology).




                                          42
Id. at 50933. In this passage, the agency makes clear that because “the relationship

between changes in opacity and increases or decreases in ambient PM 2.5 levels cannot

be quantified readily for the sources subject to this SIP revision” and because there are

at least four distinct reasons that little or no change in opacity might yet be

accompanied by a significant increase in actual emission of particulate matter, the

EPA cannot say whether the proposed revision “would interfere with any applicable

requirement concerning attainment.” Because § 110(l) of the Clean Air Act requires

the EPA to ensure that the proposed revision will not interfere with any applicable

requirement concerning attainment, the EPA’s approval did not comply with the Act.

That is the identified error or mistake the agency made.

      The EPA also described a second error, an extension of the first, when it

announced its disapproval of the 2008 proposed revision. It said that in its prior

approval of the revision:

      [W]e established a new metric of “average daily opacity” (and “average
      quarterly opacity”) and concluded that section 110(l) did not prohibit
      approval of a SIP revision that allowed significantly increased opacity
      levels for longer consecutive periods of time because the revision would
      not increase the allowable average opacity levels (on either a quarterly
      or daily basis). This analysis was focused on opacity and operational
      conditions regarding opacity as opposed to a focus on the relationship
      between opacity and PM mass emissions . . . .




                                           43
76 Fed. Reg. 18870, 18874 (Apr. 6, 2011) (emphases added). In short, the prior

analysis looked at numbers, not at what the numbers were supposed to index or

signify. The mistaken prior analysis was inconsistent with the requirements of the

Act.

       When it announced its final decision to disapprove the proposed revision, the

EPA referred back to the two identified reasons in support of approval that were stated

in its Notice of October 2, 2009. It said:

       [B]oth of the findings that provided the foundation for [EPA’s] initial
       approval of the SIP revision were not strong enough to support approval
       under the [Clean Air Act]. EPA concludes that, as it was described in the
       Submittals, the concept of “average daily opacity” is not a useful tool for
       evaluating whether the Submittals are likely to maintain current air
       quality, particularly given the lack of other limitations on opacity
       exceedances in the Submittals. . . .

76 Fed. Reg. 18870, 18874–75 (Apr. 6, 2011) (emphases added).

       All of these statements describe errors of judgment. The EPA does not use the

specific words “error” or “correction.” Nor does it identify a mathematical mistake or

linguistic slip. And it does not provide an easy descriptor of the error or expressly

invoke § 110(k)(6). But, just as the majority does not require the EPA to intone

“magic words,” Majority Op. at 28, there is no reason why such omissions should

doom the agency’s action.




                                             44
      The majority states, “Congress has required the EPA to articulate an ‘error’ and

provide ‘the basis’ of its determination that an error occurred.” Id. at 23 (emphasis

added). But that is not exactly what the Act says. The Act says the EPA may revise

its prior approval, disapproval, or promulgation whenever it determines that its action

“was in error.” Section 110(k)(6) (emphasis added). When error is spoken of as a

place, the intent is often to include misjudgment rather than mere mistake or omission.

      Because the EPA described the errors of judgment that it sought to correct,

§110(k)(6) authorized its reconsideration of its approval of Alabama’s proposed SIP

revision. That being so, the agency had not “completed its decisionmaking process”

as to the 2008 approval, Franklin v. Massachusetts, 505 U.S. 788, 797 (1992), and the

erstwhile approval became “interlocutory in nature,” National Parks Conservation

Ass’n v. Norton, 324 F.3d 1229, 1236–37 (quoting Bennett v. Spear, 520 U.S. 154,

177-78 (1997)). See also Whitman v. Am. Trucking Ass’ns, Inc., 531 U.S. 457, 479

(2001). Therefore, I would dismiss the 2008 action for lack of jurisdiction.

                                          II.

      I would also uphold the EPA’s action in 2011 disapproving the proposed

revision. The proposal, after all, would apply not only to the coal-fired utilities

represented in this action but also to cement manufacturing facilities, as well as pulp

and paper facilities, entities which might generate different kinds of particulate matter

                                           45
in different ways with different consequences. See 76 Fed. Reg. 18873 & n.8; 74 Fed.

Reg. at 50933. The EPA found that, while “[o]ne of the primary purposes of opacity

limits is to ensure that PM control devices are operating within normal parameters,”

the proposed revision might result in failure to alert an operator or the State or EPA

to an equipment malfunction that is not only causing increased opacity but failing to

control types of PM emissions that the operator mistakenly believes to be under

control. 76 Fed. Reg. at 18874. “[A] rule that allows no more than one 6-minute

exceedance per hour and opacity readings no greater than 40 percent clearly requires

more effective control equipment and/or operating procedures than . . . a rule that

allows longer consecutive periods of exempt opacity excursions and at higher opacity

levels.” Id. at 18876.

       Further, the EPA found:

       [E]lements that are missing from the submitted modeling include: data
       from all the sources and source categories affected by the Alabama
       Submittals[1] ; a demonstration of the relationship between PM emissions
       and opacity at a particular facility and source-category; consideration of
       emissions from other sources in the modeled area; condensable PM data;
       explanation for background PM levels used in the evaluation; and an
       explanation of the use of PM 10 as a surrogate for PM 2.5; among other
       concerns.



       1
         For instance, while Alabama Power Company submitted models, cement manufacturers
and pulp and paper facilities, whose operations would also be affected by the proposed revision,
apparently did not. 74 Fed. Reg. at 50933; 76 Fed. Reg. at 18873.

                                               46
Id. at 18875. The EPA concluded that “it is reasonably foreseeable that approving the

Alabama Submittals would allow increased mass emissions, for at least some sources

and under at least some conditions, over the PM emission levels that would have been

allowed” under the previous rule.         Consequently, “[S]ection 110(l) requires

disapproval . . . absent additional limitations which would significantly diminish the

likelihood that mass emissions increases will occur.” Id. at 18876.

      In its 2011 disapproval, in my view, the EPA permissibly construed § 110(l) and

acted neither arbitrarily nor capriciously when it determined that an increase in opacity

limits will “interfere” with the PM2.5 standard for attainment by making it more

difficult for operators to spot malfunctions and by exempting more emissions of

particulate matter. Although opacity is not attainment and is not an air-quality

standard, it is aptly described as an “applicable requirement concerning attainment.”

These determinations are squarely within the heartland of EPA expertise and the

sphere of judicial deference to it under Chevron. That being so, the law requires us

to defer to the agency determination in this case where the meaning of words or

phrases in a statute or regulation is evident from context. See Nat’l Ass’n of Home

Builders vs Defenders of Wildlife, 551 U.S. 644, 666 (2007).

      Of greater concern is what I perceive will be the consequence of the majority’s

reasoning. The EPA’s Notice of October 2, 2009, solicited input on whether its 2008

                                           47
approval was, in fact, “in error.” I believe that the EPA complied with § 110(k)(6) in

making this request for input because the statute requires it to undertake any revision

of its prior action “in the same manner as the approval” but “without requiring any

further submission from the State.” When it gave notice of its intent to reconsider, the

EPA said:

      This rulemaking is part of EPA’s reconsideration process on our October
      15, 2008, final action approving Alabama’s visible emissions SIP
      revisions. EPA is seeking public comment on proposals to affirm our
      prior action, which approved the SIP revisions, or amend and disapprove
      the revisions to Alabama SIP rule 335-3-4-.01 (“Visible Emissions”),
      submitted initially in 2003 and significantly revised and re-submitted on
      August 22, 2008.

74 Fed. Reg. at 50934.

      The EPA could have simply decreed in 2009 that it made an error of judgment

in approving Alabama’s proposed revision because the evidence was not sufficient to

ensure that allowing opacity greater than 20% for more extended periods of time

would not result in emission of more particulate matter. Had it done so, under the

majorities’ reasoning we could not now conclude that the EPA’s reconsideration was

faulty. It is not particularly unusual for a change in philosophy within an agency to

result in a policy about-face or to perceive error in earlier decisions. See, e.g., FCC

v. Fox Television Stations, Inc., 556 U.S. 502, 514–15 (2009); Nat’l Ass’n of Home

Builders v. EPA, 682 F.3d 1032, 1034–39 (D.C. Cir. 2012); Chamber of Commerce

                                          48
v. EPA, 642 F.3d 192, 196–66 (D.C. Cir. 2011); see also Sierra Club v. Ga. Power

Co., 443 F.3d 1346, 1353–54 & n.11 (11th Cir. 2006) (describing the EPA’s

clarification in 2001 of guidance that it provided in 1999). What one person calls “a

reevaluation of which policy would be better in light of the facts,” Home Builders, 682

F.3d at 1038, another person may reasonably call a determination that prior policy was

“in error,” § 110(k)(6).

       But, here, instead of taking wholly on itself the determination that an error

occurred, EPA invited the interested parties to provide input on the question of

whether it erred. It specifically asked for plant- or industry-specific data about the

relationship between opacity and real amounts of particulate emissions into the

ambient air. As a result of the EPA’s willingness to listen to these responses and

consider additional data from interested parties before it made a final decision whether

to change course, the majority concludes that the EPA exceeded its authority. If this

reasoning is correct, and I do not think it is, the lesson for the EPA is—declare errors

first, and investigate whether they exist later. It has a “verdict first, evidence later”

feel to it.

       No one affected by EPA’s decision in this case claims they were unable to

understand why the agency was concerned about its prior action. On the contrary,

both the State and the utility industries avoid making any such claim, asserting instead

                                           49
that EPA failed to identify a “technical or clerical error”—words that cannot be found

in § 110(k)(6)’s phrase “in error.” No one has even attempted to refute the EPA’s

concern about the relationship between opacity and particulate matter or that

consideration of the relationship is an issue wholly within the mainstream of the

agency’s responsibilities.

       In my view, the process functioned just as it is supposed to. The EPA did not

hide the ball, it did not do anything that was irrational, arbitrary, or capricious, it gave

ample opportunity to interested groups to explain their own positions and allay the

EPA’s concerns, and, at least in my opinion, it clearly explained its own concerns and

final decision. I believe the record fails to support the appellant’s position and, under

applicable law, supports the EPA’s actions and decision.

       The majority’s conclusion that the EPA “failed to articulate an error” reflects

a determination of what the majority expects the articulation of error to sound like and

less to do with the EPA’s process or its findings about air quality and particulate

matter.

       When the question is whether the EPA had authority to reconsider under

§ 110(k)(6), we should read what the agency said in the Federal Register in the

particular case at hand and ask whether the agency says that it was wrong on a prior

occasion. Doing so remains the best way to avoid asking for “magic words” and is

                                            50
the best way to determine whether the agency’s actions—regardless of its brief or oral

argument, see Majority Op. at 25–26 & n.11—were consistent with the law enacted

by Congress.

      For these reasons, I respectfully dissent.




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