FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

BILL MACCLARENCE,                          
                             Petitioner,
               v.
                                           
                                                  No. 07-72756
UNITED STATES ENVIRONMENTAL                        OPINION
PROTECTION AGENCY; STEPHEN L.
JOHNSON,
                    Respondents.
                                           
          On Petition for Review of an Order of the
             Environmental Protection Agency

                    Argued and Submitted
              February 5, 2009—Portland, Oregon

                       Filed March 4, 2010

     Before: Richard A. Paez and Johnnie B. Rawlinson,
    Circuit Judges, and Raner C. Collins,* District Judge.

                     Opinion by Judge Paez




  *The Honorable Raner C. Collins, United States District Judge for the
District of Arizona, sitting by designation.

                                3409
                 MACCLARENCE v. USEPA                3411




                       COUNSEL

Robert Ukeiley, Law Office of Robert Ukeiley, Berea, Ken-
tucky, William M. Eddie, Field Jerger, LLP, Portland, Ore-
gon, for the petitioner.
3412               MACCLARENCE v. USEPA
Ronald J. Tenpas, Assistant Attorney General, John C. Cru-
den, Deputy Assistant Attorney General, Andrew J. Doyle,
Attorney, Environment & Natural Resources Division,
Department of Justice, Washington, DC, Kristi M. Smith,
Office of General Counsel, Environmental Protection Agency,
Washington, DC, Julie A. Vergeront, Office of Regional
Counsel, Region 10, Environmental Protection Agency, Seat-
tle, Washington, for respondents United States Environmental
Protection Agency, and Stephen L. Johnson, Administrator,
United States Environmental Protection Agency.


                         OPINION

PAEZ, Circuit Judge:

   Bill MacClarence petitions this court for review of an order
by the Environmental Protection Agency Administrator (the
“Administrator”) denying his request that the Environmental
Protection Agency (“EPA”) object to the issuance of a Clean
Air Act Title V permit for pollutant-emitting activities at
Gathering Center #1 (“GC 1”), an oil and gas processing
facility in Prudhoe Bay. The Alaska Department of Environ-
mental Conservation’s (“ADEC”) granted the permit to
British Petroleum Exploration (Alaska), Inc.’s (“BP”), which
owns GC 1. We have jurisdiction to review MacClarence’s
petition for review pursuant to 42 U.S.C. §§ 7661d(b)(2) and
7607(b)(1). Because the Administrator’s denial of MacClar-
ence’s request was not arbitrary or capricious, we deny the
petition.

I.    Background

     A.   The Prudhoe Bay Unit

   The Prudhoe Bay Unit (PBU) is located on the North Slope
of Alaska and extends over 300 square miles. It consists of a
                       MACCLARENCE v. USEPA                           3413
series of oil and gas facilities, including thirty-eight drill sites
or “well pads” and six production centers, as well as support
facilities for PBU workers. GC 1 is one of the six production
facilities at the PBU. BP owns approximately 26.35% to
50.7% of the facilities at the PBU, including GC 1, and oper-
ates all of the PBU facilities pursuant to an agreement with
the other owners. Although the PBU oil field is composed of
a number of different oil leases, those leases have been unit-
ized or pooled by the State of Alaska so that the field may be
exploited efficiently.

   The PBU facilities are engaged in a continuum of oil and
gas refining activities, from drilling to sale.1 Well pads in the
PBU pump “three-phase” crude oil from the tundra beneath
the PBU facilities. This oil is transferred to the production
centers, including GC 1, where it is separated into processed
crude oil, water, and hydrocarbon gases. The processed crude
oil is pumped from the production centers to the Trans-Alaska
Pipeline for sale, while other facilities at the PBU dispose of
or re-inject the by-products of the production process.

  B.    Title V of the Clean Air Act

   MacClarence petitioned the Administrator to object to a
final permit issued for GC 1 pursuant to Title V of the Clean
Air Act (the “CAA”), 42 U.S.C. §§ 7401 et seq. The CAA
was enacted in 1963 to “protect and enhance the quality of the
Nation’s air resources so as to promote the public health and
welfare and the productive capacity of its population.”
§ 7401(b)(1). Built on a scheme of “cooperative federalism,”
  1
    The various functions and the interconnectedness of the PBU facilities
are too complex to describe fully here. The brief description of the facili-
ties and activities of the PBU is intended only to provide background and
context for our opinion. For a more extensive discussion of the PBU oil
and gas production and processing facilities, see generally Alaska Depart-
ment of Environmental Conservation Air Quality Operating/Construction
Permit, Permit No. 182TVP01 (Feb. 17, 2004) (“Revision 1”),
http://www.dec.state.ak.us/air/ap/docs/182tvp01r1.pdf.
3414               MACCLARENCE v. USEPA
the CAA places the onus of enforcement on state and local
governments, but “provides for ‘Federal financial assistance
and leadership . . . for the development of cooperative, Fed-
eral, State, regional, and local programs to prevent and control
air pollution.’ ” N.Y. Pub. Interest Research Group v. Whit-
man (NYPIRG I), 

, 320 (2d Cir. 2003) (quoting
42 U.S.C. § 7401(a)(3), (4); Connecticut v. EPA, 

, 151 (2d Cir. 1982)).

   The Clean Air Act Amendments of 1990, Pub. L. No. 101-
549, §§ 501-07, 104 Stat. 2399, 2635-48 (1990), enacted Title
V of the CAA, which requires facilities that are “major
sources” of pollutants to obtain operating permits from state-
run permitting programs that have been approved by EPA.
See 42 U.S.C. § 7661a. ADEC is Alaska’s EPA-approved
Title V permitting authority. 66 Fed. Reg. 63,184, 63,184
(Dec. 5, 2001). Each permit must “include enforceable emis-
sion limitations and standards, a schedule of compliance, a
requirement that the permittee submit to the permitting
authority . . . the results of any required monitoring, and such
other conditions as are necessary to assure compliance with
applicable requirements of [the CAA].” 42 U.S.C. § 7661c(a).
Title V, however, does not itself impose additional substan-
tive clean air standards. 40 C.F.R. § 70.1(b).

   Title V further provides for both EPA and public review of
permits. 42 U.S.C. § 7661d; 40 C.F.R. § 70.8(d). After a per-
mitting authority receives an application for a Title V permit,
it is required to submit a copy of the permit application and
the “permit proposed to be issued and issued as a final per-
mit” to EPA, 42 U.S.C. § 7661d(a)(1)(B), and to provide the
public with notice and opportunity to comment on the draft
permit, 40 C.F.R. § 70.7(h). If the permit “contains provisions
that are determined by the Administrator as not in compliance
with the applicable requirements of [the CAA],” the Adminis-
trator, within forty-five days of receiving the proposed permit,
“shall . . . object to its issuance.” 42 U.S.C. § 7661d(b)(1).
                       MACCLARENCE v. USEPA                          3415
   If the EPA does not object to the permit within this time
frame, however, “any person” may petition the Administrator
to make an objection within sixty days after the expiration of
EPA’s period of review. 

The petition must
be based on objections that were made “with reasonable spec-
ificity during the public comment period” on the draft permit.

petitioner demonstrates to the Administrator that
the permit is not in compliance with the requirements of [the
CAA],” Title V provides that the Administrator “shall issue
an objection . . . .” 

does object to a permit, “the
permitting authority may not issue the permit unless it is
revised” to meet the objection. 

(c).

  C.    Aggregation

   Here, MacClarence petitioned for an objection pursuant to
§ 7661d(b)(2), arguing that the permit did not comply with
the CAA because ADEC, in the final draft permit for GC 1,
had not properly “aggregated” stationary sources of air pollu-
tion in the PBU. Title V and other CAA provisions, such as
the “prevention of significant deterioration” (PSD) require-
ments, 42 U.S.C. §§ 7470-79, apply to certain “stationary
sources” of air pollution. In some cases, several discrete sta-
tionary sources may be required to be aggregated into one sin-
gle stationary source for purposes of compliance with these
provisions.2 For example, as noted above, Title V requires
every “major source” of air pollution to obtain a permit. 42
U.S.C. § 7661a(a). The Title V regulations, in turn, define
“major source” as a “stationary source (or any group of sta-
tionary sources that are located on one or more contiguous or
adjacent properties, and are under common control of the
same person (or persons under common control)) belonging
to a single major industrial grouping . . . .” 40 C.F.R. § 70.2
(emphasis added).
  2
    In making “stationary source” determinations, ADEC looks to the defi-
nitions of “stationary source” outlined in the federal PSD and Title V reg-
ulations. See Alaska Stat. § 46.14.990(26) (citing 40 C.F.R. 51.116(b)
(PSD requirements) and 40 C.F.R. § 70.2 (Title V requirements)).
3416                MACCLARENCE v. USEPA
   Similarly, the PSD requirements, which “ensure that the air
quality in attainment areas or areas that are already ‘clean’
will not degrade,” Alaska Dep’t of Envtl. Conservation v.
EPA, 

, 470 (2004) (quoting R. Belden, Clean Air
Act 43 (2001)), may require the aggregation of stationary
sources. Under the PSD requirements, “major stationary
sources” may not be constructed or modified in a significant
way “unless a permit prescribing emission limitations has
been issued for the facility.” 

(citing 42 U.S.C.
§§ 7475(a)(1), 7479(2)(C)). A “major stationary source,” for
PSD purposes, is a “stationary source” that emits or has the
potential to emit a certain quantity of pollutants. 42 U.S.C.
§§ 7479(1), 7602(j). In turn, a “stationary source” is “any
building, structure, facility, or installation which emits or may
emit a regulated . . . pollutant.” 40 C.F.R. § 51.166(b)(5). The
regulations define “[b]uilding, structure, facility, or installa-
tion” as “all of the pollutant-emitting activities which belong
to the same industrial grouping, are located on one or more
contiguous or adjacent properties, and are under the control of
the same person . . . .” 

   As the record for this case reveals, the aggregation of
pollutant-emitting activities for the purposes of designating a
“major source” or “major stationary source” is not a clear-cut
task. Under the governing regulations, however, determina-
tions regarding “major sources” for purposes of issuing Title
V permits and “major stationary sources” for purposes of
meeting PSD requirements involve the same analysis; the
aggregated sources must belong to the same industrial group-
ing, be located on continuous or adjacent properties, and be
under common control. See 40 C.F.R. §§ 51.166(b)(6), 70.2.
Over the years, EPA has provided some guidance on the
aggregation of pollutant-emitting activities and the designa-
tion of “major sources” and “major stationary sources.” When
EPA promulgated regulations for the PSD program in 1980,
it noted that a “stationary source” should reflect “a common
sense notion of ‘plant.’ ” 45 Fed. Reg. 52,676, 52,694-95
(Aug. 7, 1980). EPA has also issued memoranda in order to
                   MACCLARENCE v. USEPA                   3417
provide regional EPA administrators and state permitting
authorities with guidance in applying aggregation principles
to designate stationary sources. See, e.g., Memorandum from
Acting Assistant Administrator, EPA, to Regional EPA
Administrators, Source Determinations for Oil and Gas Indus-
tries (Jan. 12, 2007), EPA docket EPA-HQ-OAR-2007-0629-
0001.pdf,       http://www.regulations.gov/search/Regs/content
Streamer?objectId=0900006480269a33&disposition=
attachment&contentType=pdf (withdrawn by Gina McCarthy,
Assistant Administrator, EPA, to Regional EPA Administra-
tors, Withdrawal of Source Determinations for Oil and Gas
Industries (September 22, 2009), EPA docket EPA-HQ-OAR-
2007-0629-0003.pdf,         http://www.regulations.gov/search/
Regs/contentStreamer?objectId=0900006480a3309c&
disposition=attachment&contentType=pdf);        Letter   from
Director, Air Program, EPA, to Utah Division of Air Quality,
Response to Request for Guidance in Defining Adjacent with
Respect to Source Aggregation (May 21, 1998), http://
www.epa.gov/region07/programs/artd/air/title5/t5memos/util-
trl.pdf.

  D.   The Permitting Process for GC 1

   With this statutory and regulatory framework in mind, we
turn to the permitting process for GC 1. In 1997, ARCO, then
the owner of GC 1, applied to ADEC for a Title V permit.
ADEC prepared a draft permit and submitted it for public
comment on February 22, 2002. This initial draft permit did
not aggregate GC 1 with any other potential pollutant-
emitting sources in the PBU. The following month, MacClar-
ence submitted comments on the draft permit, arguing that
“[a]ll BP units within the Prudhoe Bay Facility” should be
aggregated in such a way that the Title V permit applied to the
PBU as a whole, rather than just GC 1. In April 2002, the
Pacific Northwest Regional Office of the EPA (EPA Region
10) also submitted “preliminary comments” to ADEC regard-
ing the GC 1 draft permit. Echoing MacClarence’s concerns,
EPA stated,
3418               MACCLARENCE v. USEPA
    [A]bsent a contrary rationale, it is EPA’s position
    that the BP GC 1 facility is part of the larger source
    consisting of all BP units within the Prudhoe Bay
    . . . . [T]he BP facilities are interdependent, located
    on adjacent properties, and are owned or operated by
    the same person under common control.

   ADEC revised the draft permit and submitted a new draft
permit for public comment in March 2003. ADEC again pro-
posed to extend coverage of the operations permitted under
Title V only to GC 1. Significantly, however, ADEC also pro-
posed a condition that would require BP to aggregate all of
the pollutant-emitting sources within the PBU “for the pur-
pose of determining applicability with the modification
requirements of [Alaska’s approved PSD program].” The
revised permit’s Statement of Basis explained in detail why
the PBU in its entirety should be considered a “major station-
ary source,” referencing CAA provisions and EPA guidance
on aggregation, and used diagrams to depict the interconnec-
tedness of the various pollutant-emitting sources within the
PBU. ADEC concluded by stating that “[t]he individual facili-
ties at the Prudhoe Bay Unit act as a single integrated produc-
tion facility for the purpose of delivering crude oil to the
Trans Alaska Pipeline System . . . .”

   In response to the March 2003 draft permit, BP submitted
comments requesting that aggregation conditions be com-
pletely eliminated from the permit. Shortly thereafter, in July
2003, ADEC reversed course and issued a proposed permit
that, like the initial draft permit, did not aggregate GC 1 with
any other PBU facilities. In August 2003, EPA responded to
this proposed permit by requesting that ADEC

    postpone issuing draft, proposed and final Title V
    permits for those North Slope operations which raise
    aggregation issues until the agencies have come to a
    mutual understanding on an over-arching approach
    to the issue or until either agency has advised the
                    MACCLARENCE v. USEPA                      3419
    other that it has decided to forego further attempts to
    reach a mutual understanding.

BP was included in ADEC’s and EPA’s ensuing conversa-
tions regarding aggregation of pollutant-emitting sources in
the North Slope.

   In October 2003, after these discussions concluded, ADEC
issued a new draft permit that employed a “hub-and-spoke”
aggregation model. Under this model, ADEC aggregated GC
1 with the well pads that supply it with three-phase crude oil
for purposes of Title V and for the PSD requirements. The
draft permit, however, did not aggregate GC 1 with the rest
of the PBU facilities as had been requested by MacClarence
in his March 2002 comments. In a Statement of Basis for “Re-
vision 1,” discussed infra, ADEC explained that it rejected
aggregation of the entire PBU facilities because, among other
things (1) the PBU covers roughly 300 square miles and
therefore aggregation “stretches the concept of proximity”
that underlies aggregation determinations; (2) “[t]he complex-
ity of administering . . . and operating . . . a stationary source
as large as the PBU without clear corresponding environmen-
tal benefit argues against” aggregation of the entire PBU; and
(3) “there [was] no precedent for defining such a large station-
ary source . . . .”

   When the EPA, in February 2004, did not object to this per-
mit under 42 U.S.C. § 7661d(b), MacClarence petitioned the
EPA Administrator to object to the permit. This petition, like
MacClarence’s March 2002 comments, argued that the permit
violated the CAA because it did not aggregate all of the
pollutant-emitting sources in the PBU into one stationary
source. MacClarence attached to the petition his 2002 com-
ments, ADEC’s March 2003 Statement of Basis, and EPA’s
August 2003 letter to ADEC requesting a postponement of
ADEC’s issuance of any permits involving aggregation issues
in the North Slope.
3420                    MACCLARENCE v. USEPA
   After MacClarence submitted his petition, EPA notified
him that ADEC had issued a revision to the final permit, “Re-
vision 1.” Revision 1, among other things, “added to the per-
mit itself the definition of the title V source, which was
previously only in the statement of basis” and “made minor
changes to the aggregation discussion in the statement of
basis.” Pursuant to EPA’s request, MacClarence refiled his
petition for an objection to the permit on April 14, 2004.3 He
resubmitted his original petition with a cover letter stating that
his petition remained unchanged as Revision 1 did not address
his concerns and did not explain ADEC’s decision to reverse
course from its March 2003 draft permit that required aggre-
gation.

   The Administrator denied MacClarence’s request for an
objection on April 20, 2007.4 MacClarence timely petitioned
this court for review of EPA’s denial of his request for an
objection.

II.    Discussion

   In considering MacClarence’s petition for review, we do
not decide whether MacClarence’s substantive argument—
that the CAA requires all pollutant-emitting sources in the
PBU to be aggregated for purposes of Title V and other sub-
stantive CAA provisions—is correct. Rather, we consider
  3
     Revision 1 was the version of the final permit to which MacClarence
responded in his petition to the EPA Administrator. Alaska Department of
Environmental Conservation Air Quality Operating/Construction Permit,
Permit No. 182TVP01 (Feb. 17, 2004) (“Revision 1”), http://
www.dec.state.ak.us/air/ap/docs/182tvp01r1.pdf. ADEC, however, revised
the permit yet again in August 2005, “Revision 2”. Because MacClarence
petitioned for an objection prior to Revision 2, any future references to
“the final permit,” or its Statement of Basis, are to the final permit as mod-
ified by Revision 1.
   4
     MacClarence does not challenge EPA’s unexplained failure to respond
to his petition within the sixty-day period required by statute. See 42
U.S.C. § 7661d(b)(2).
                    MACCLARENCE v. USEPA                     3421
only whether the EPA Administrator erred in determining that
MacClarence failed to demonstrate, pursuant to 42 U.S.C.
§ 7661d(b)(2), that the final Title V permit for GC 1 did not
comply with the CAA.

   In denying MacClarence’s request, the Administrator rea-
soned that MacClarence (1) “failed to provide adequate infor-
mation to support his claim that the entire PBU should be
aggregated,” and (2) “failed to demonstrate that the failure to
aggregate all facilities within the PBU has led to a deficiency
in the content of the permit.” Because we conclude that we
may properly uphold the Administrator’s denial of MacClar-
ence’s petition on the basis of the first ground, we need not
reach the second.

  A.   Standard of Review

   Our review of the “the reasonableness of [the Administra-
tor’s] decision-making processes” in denying MacClarence’s
petition is governed by the Administrative Procedure Act
(APA). CHW W. Bay v. Thompson, 

, 1226 (9th
Cir. 2001) (citing Transitional Learning Comm. at Galveston,
Inc. v. U.S. Office of Pers. Mgmt., 

, 430 n.2 (5th
Cir. 2000)); see Sierra Club v. EPA, 

, 961 (9th
Cir. 2003). Under the APA, we may only set aside an agency
action if it is “arbitrary, capricious, an abuse of discretion, or
otherwise not in accordance with law.” 5 U.S.C. § 706(2)(A).
We review the Administrator’s interpretation of 42 U.S.C.
§ 7661d(b)(2), as expressed in its order denying MacClar-
ence’s petition, under the principles set forth in Chevron USA
Inc. v. Natural Res. Def. Council, Inc., 

(1984).
De Jesus Ramirez-Zavala v. Ashcroft, 

, 875 (9th
Cir. 2003).

  B.   MacClarence’s Petition

  [1] This petition for review requires us, for the first time,
to consider a petitioner’s burden under 42 U.S.C.
3422                MACCLARENCE v. USEPA
§ 7661d(b)(2) to “demonstrate[ ] to the Administrator that [a
Title V] permit is not in compliance with the requirements of
[the CAA].” § 7661d(b)(2). Specifically, we must determine
whether the Administrator’s interpretation of the word “dem-
onstrate,” as expressed in his order denying MacClarence’s
petition, was a permissible construction of § 7661d(b)(2), and
whether the Administrator’s application of § 7661d(b)(2) to
the petition was arbitrary and capricious.

   Chevron provides the guiding principles for according def-
erence to an agency’s interpretation of a statute it administers.

. Here, it is undisputed that EPA is tasked
with the administration of the CAA. Therefore, we first
decide “whether Congress has directly spoken to the precise
question at issue. If the intent of Congress is clear . . . the
court, as well as the agency, must give effect to the unam-
biguously expressed intent of Congress.” 

If,
however, the statute is ambiguous, “Chevron deference
applies, ‘when it appears that Congress delegated authority to
the agency generally to make rules carrying the force of law,
and that the agency interpretation claiming deference was pro-
mulgated in the exercise of that authority.’ ” Nw. Ecosystem
Alliance v. United States Fish & Wildlife Serv., 

, 1141 (9th Cir. 2007) (quoting United States v. Mead
Corp., 

, 226-27 (2001)). Under Chevron defer-
ence, the agency’s interpretation is valid so long as it “is
based on a permissible construction of the statute.” 

. When Chevron deference does not apply, we
are guided by the principles of Skidmore v. Swift, 

(1944); “[t]he ‘fair measure of deference’ may then range
from ‘great respect’ to ‘near indifference,’ depending on ‘the
degree of the agency’s care, its consistency, formality, and
relative expertness, and . . . the persuasiveness of the agency’s
position.’ ” Nw. Ecosystems 

(quot-
ing 

).

  [2] Several of our sister circuits have concluded that the
word “demonstrate” in § 7661d(b)(2) is an ambiguous term.
                   MACCLARENCE v. USEPA                    3423
See Sierra Club v. EPA, 

, 406 (6th Cir. 2009);
Sierra Club v. Johnson (Sierra Club II), 

, 1266
(11th Cir. 2008); Citizens Against Ruining the Environment v.
EPA, 

, 677-78 (7th Cir. 2008); N.Y. Pub. Interest
Research Group v. Johnson (“NYPIRG II”), 

,
179 (2d Cir. 2005). We agree. The word “demonstrate” may
mean variously, to “point out;” “to manifest clearly, certainly,
or unmistakably;” or “to make evident or reveal as true by
reasoning processes, concrete facts and evidence, experimen-
tation, operation, or repeated examples.” Webster’s Third New
International Dictionary 600 (1993). As the Eleventh Circuit
pointed out in Sierra Club II, the plain meaning of the term
“demonstrate” in § 7661d(b)(2) “does not resolve important
questions that are part and parcel of the Administrator’s duty
to evaluate the sufficiency of a petition, for example, the type
of evidence a petitioner may present and the burden of proof
guiding the Administrator’s evaluation of when a sufficient
demonstration has 

. The ambigu-
ity of this provision in the statute suggests that Congress has
left the meaning of “demonstrate” open for EPA to supply a
reasonable interpretation under Chevron. See NYPIRG 

n.11 (“There clearly is some room for the exercise
of agency expertise in [§ 7661d(b)(2)] . . . .”).

   [3] Whether we defer to the Administrator’s interpretation
of “demonstrate” under Chevron’s reasonableness standard or
Skidmore’s persuasiveness standard, nothing in the Adminis-
trator’s order denying MacClarence’s petition qualifies as an
impermissible interpretation of his burden under
§ 7661d(b)(2). The Administrator denied MacClarence’s peti-
tion, in part, because MacClarence “failed to provide adequate
information to support his claim that the entire PBU should
be aggregated . . . .” Specifically, he noted that MacClarence
“ma[d]e only generalized statements that all facilities in the
PBU must be aggregated and d[id] not provide adequate refer-
ences, legal analysis, or evidence in support of these general
assertions.”
3424               MACCLARENCE v. USEPA
   [4] This construction of MacClarence’s burden under
§ 7661d(b)(2) is both reasonable and persuasive, and is con-
sistent with our common understanding of the word “demon-
strate.” The Administrator’s expectation that MacClarence
provide “references, legal analysis, or evidence” comports
with Webster’s definition of “demonstrate”—“to make evi-
dent or reveal as true by reasoning processes, concrete facts
and evidence, experimentation, operation, or repeated exam-
ples.” New International 

. Further,
the Administrator’s interpretation is consistent with
§ 7661d(b)(2) as a whole, which mandates that the Adminis-
trator “shall issue an objection” to the permit with which the
permitting authority must comply, should a petitioner satisfy
his burden under the statute. See Sierra Club v. Johnson
(Sierra Club I), 

, 1280 (11th Cir. 2006) (quot-
ing 42 U.S.C. § 7661d(b)(2)) (holding that the Administra-
tor’s duty to object to a permit once a petitioner demonstrates
that it does not comply with the CAA is mandatory, not dis-
cretionary); NYPIRG 

(same). Because a
petition that properly demonstrates that a permit is not in
compliance with the CAA requires the Administrator and
state permitting authority to take certain action, the Adminis-
trator’s requirement that MacClarence support his allegations
with legal reasoning, evidence, and references is reasonable
and persuasive.

   [5] Thus, the Administrator’s conclusion that MacClarence
“failed to provide adequate information to support his claim
that the entire PBU should be aggregated” was not arbitrary
or capricious. The success of MacClarence’s petition turned
on his argument that aggregation of the entire PBU pollutant-
emitting sources was necessary for the permit to comply with
the CAA and that the final aggregation decision — the hub-
and-spoke model — did not comply with the CAA. Rather
than offering a reasoned analysis of why the entire PBU
should be aggregated or of the deficiencies in the hub-and-
spoke model, MacClarence merely stated in his petition:
                       MACCLARENCE v. USEPA                          3425
      As reinforced by ADEC’s original analysis, shown at
      Attachment 2, the March 7, 2003 version of this per-
      mit complies with all federal requirements for source
      aggregation. ADEC’s rationale for requiring aggre-
      gation is based on EPA directives. By contrast, the
      permit decisions referenced in the final permit are at
      variance with your agency’s own guidance.

   Although MacClarence’s March 2002 comments and
ADEC’s March 2003 Statement of Basis, which were
attached to the petition, provided an explanation of why
aggregation of the entire PBU pollutant-emitting sources was
necessary to comply with the CAA, he merely alleged that the
final aggregation decision, the hub-and-spoke model, was “at
variance with [EPA’s] own guidance.”5 Neither MacClar-
ence’s petition nor the documents attached to the petition
address EPA guidance memoranda or directives with which
the hub-and-spoke model conflicted or explained how the
hub-and-spoke model contravened such guidance or the CAA.6

   At the end of his petition, MacClarence did challenge
ADEC’s reliance on permit decisions by other states to sup-
port its final aggregation decision. His brief discussion of
these references, however, noted only that the facilities at
issue in those other permit decisions were dissimilar to the
PBU, and at best, showed that those permit decisions did not
support ADEC’s decision to adopt a hub-and-spoke aggrega-
tion model. MacClarence made no attempt to show that the
  5
     MacClarence argues that the Administrator did not consider the docu-
ments he attached to his petition in evaluating his arguments and thus pro-
hibited him from “incorporating by reference” arguments and other
information. In light of the Administrator’s statement that he considered
“available information, including . . . information provided by the Peti-
tioner in his petition,” we are not persuaded by this argument.
   6
     MacClarence’s attempt to challenge the merits of the hub-and-spoke
aggregation model before this court are unavailing. Our review is limited
to the record before the Administrator. Asarco, Inc. v. EPA, 

, 1158-60 (9th Cir. 1980).
3426                MACCLARENCE v. USEPA
hub-and-spoke model was at “variance” with the CAA or any
other EPA guidance.

   MacClarence also argues that the Administrator improperly
faulted him for failing to challenge the reasonableness of
ADEC’s Statement of Basis for the final permit. In denying
MacClarence’s petition, the Administrator stated that Mac-
Clarence “does not provide any argument as to why ADEC’s
decision not to aggregate [the entire PBU], which is described
in great detail in the Statement of Basis for the final Revision
1 permit, is unreasonable.” MacClarence argues that this
statement reflects an improper interpretation of his burden
under § 7661d(b)(2) by requiring him to show the “unreason-
ableness” of ADEC’s rationale for employing the hub-and-
spoke model in the final permit, rather than the final permit’s
noncompliance with the CAA.

   [6] We reject this argument. The Administrator’s order
denying MacClarence’s petition properly sets forth MacClar-
ence’s burden under § 7661d(b)(2), stating that “[t]o justify
exercise of an objection by EPA to a title V permit pursuant
to [§ 7661d(b)(2)], a petitioner must demonstrate that the per-
mit is not in compliance with the requirements of the CAA”
and later concluding that “the general allegations of the Peti-
tioner in the April 2004 Petition . . . fail to demonstrate a basis
for Petitioner’s claim that Revision 1 to the GC 1 Permit vio-
lates the CAA . . . .” In light of the Administrator’s proper
recitation of MacClarence’s burden, we view the Administra-
tor’s statement that MacClarence should have shown that
ADEC’s explanation for its aggregation decision was unrea-
sonable, as requiring MacClarence to challenge the basis or
reasons for ADEC’s final decision and to demonstrate that the
permit did not comply with the CAA. We see nothing wrong
with the Administrator’s expectation that MacClarence
needed to challenge this reasoning. MacClarence’s petition
relied on ADEC’s March 2003 Statement of Basis. ADEC,
however, rejected the aggregation decisions reflected in that
Statement of Basis and explained why it did so in the new
                    MACCLARENCE v. USEPA                     3427
Statement of Basis for the final permit. The Administrator
reasonably expected MacClarence to challenge that explana-
tion.

   [7] Further, the Administrator’s conclusion that MacClar-
ence did not challenge ADEC’s reasoning for the final permit
was not arbitrary or capricious. ADEC’s final Statement of
Basis explained how the hub-and-spoke aggregation model
complied with the CAA, why complete aggregation of the
facilities in the PBU was impractical and unprecedented, and
why the hub-and-spoke model was a better alternative than
complete aggregation. Although MacClarence asserted in his
petition that the out-of-state permit decisions cited by ADEC
did not support its final aggregation decision, his petition
failed to demonstrate that the hub-and-spoke aggregation
model did not comply with the CAA. More importantly, Mac-
Clarence failed to challenge ADEC’s reasoning that “[t]he
complexity of administering . . . and operating . . . a stationary
source as large as the PBU without clear corresponding envi-
ronmental benefit argues against [the aggregation of the entire
PBU].”

   Therefore, we conclude that the Administrator’s determina-
tion that MacClarence did not demonstrate that the entire
PBU should be aggregated did not constitute an impermissible
interpretation of MacClarence’s burden under 42 U.S.C.
§ 7661d(b)(2), to “demonstrate” that ADEC’s final Title V
permit for BP’s GC 1 did not comply with the CAA, nor was
it arbitrary or capricious.

  PETITION DENIED.