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United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT
Argued October 19, 2007 Decided December 11, 2007
No. 06-1164
ENVIRONMENTAL DEFENSE, INC., ET AL.,
PETITIONERS
v.
ENVIRONMENTAL PROTECTION AGENCY AND
STEPHEN L. JOHNSON, ADMINISTRATOR,
RESPONDENTS
On Petition for Review of an Order of the
Environmental Protection Agency
Robert E. Yuhnke argued the cause for petitioners. With
him on the briefs was Joanne M. Spalding.
David J. Kaplan, Attorney, U.S. Department of Justice,
argued the cause for respondents. With him on the brief was
John C. Cruden, Deputy Assistant Attorney General.
Before: GINSBURG, Chief Judge, and ROGERS and BROWN,
Circuit Judges.
2
Opinion for the Court filed by Circuit Judge ROGERS.
ROGERS, Circuit Judge: Environmental Defense, Inc., the
Natural Resources Defense Council, and the Sierra Club petition
for review of a final rule promulgated by the Environmental
Protection Agency to regulate “hot spot” analyses undertaken as
part of the transportation conformity determinations required by
the Clean Air Act (“CAA”). See PM2.5 and PM10 Hot Spot
Analyses in Project-Level Transportation Conformity
Determinations for the New PM2.5 and Existing PM10 National
Ambient Air Quality Standards (“Final Rule”), 71 Fed. Reg.
12,468, 12,470-74 (Mar. 10, 2006) (to be codified at 40 C.F.R.
pt. 93). Petitioners seek a remand of sections 93.116 and 123(b)
of the Final Rule on the ground that they fail to implement the
conformity conditions in CAA §§ 176(c)(1)(A) and (B)(iii).
Petitioners also seek vacatur of EPA’s decision to withdraw a
previously announced emissions model from use in “hot spot”
analyses on the ground that EPA failed to give prior adequate
notice or opportunity for comment.1 We grant the petition in
part and deny it in part. Because petitioners fail to show that
EPA’s interpretation of CAA § 176(c)(1)(A) is unreasonable or
that EPA failed to give adequate notice and opportunity for
comment prior to withdrawing the model, we deny the petition
as to those contentions. However, if “any area” properly means
“a local area” under CAA § 176(c)(1)(B)(i) and (B)(ii), then it
is arbitrary and capricious not to define the term similarly in
(B)(iii) or not to explain why the term there means something
different. We therefore grant the petition and remand the Final
Rule for EPA either to interpret (B)(iii) in harmony with (B)(i)
and (B)(ii) or to explain why it need not do so.
1
The court severed Petitioners’ other challenges to the Final
Rule pursuant to a joint motion of the parties in light of settlement
discussions. Envtl. Def. v. EPA, No. 06-1164 (D.C. Cir. June 14,
2007).
3
I.
Pursuant to the CAA, EPA has established National
Ambient Air Quality Standards (“NAAQS”) that regulate air
contaminants, including particulate matter measuring less than
ten micrometers (“PM10”) and less than 2.5 micrometers
(“PM2.5”). The states, in turn, have prepared State
Implementation Plans (“SIPs”) to “provide[] for
implementation, maintenance, and enforcement of [NAAQS] in
each air quality control region (or portion thereof) . . . .” CAA
§ 110(a)(1), 42 U.S.C. § 7410(a)(1). See generally Envtl. Def.
Fund v. EPA (“EDF II”), 167 F.3d 641, 643-46 (D.C. Cir.
1999); S. Coast Air Quality Mgmt. Dist. v. EPA, 472 F.3d 882,
886-87 (D.C. Cir. 2006). The CAA requires that states be
divided into specific areas, which are rated “nonattainment” if
air quality standards do not comply with the NAAQS,
“attainment” if they do, or “maintenance” if they have passed
from nonattainment to attainment status. CAA
§§ 107(d)(1)(A)(I)-(ii); 3(E), 42 U.S.C. §§ 7407(d)(1)(A)(I)-(ii);
(3)(E).
The federal conformity rule, first adopted in 1977,
prohibited federal agencies from assisting, supporting, or
approving transportation activities that do not conform to a
state’s SIP. See Criteria and Procedures for Determining
Conformity to State or Federal Implementation Plans, 58 Fed.
Reg. 62,188, 62,189 (Nov. 24, 1993). State-designated
metropolitan planning organizations (“MPOs”) for certain urban
areas, as required by the federal highway law,2 could not approve
2
Thus, states must designate an MPO in each urban area with
a population over 50,000 persons. 23 U.S.C. § 134(d). The MPO, in
turn, must prepare a 20-year regional transportation plan, id. at §
134(I), and a transportation improvement program (“TIP”) with a
four-year horizon. Id. at § 134(j). These “plans” and “programs”
4
transportation activities that did not conform to a SIP. Id. In the
years after adoption of the conformity rule, EPA and the U.S.
Department of Transportation (“DOT”) engaged in inconclusive
discussions about whether individual transportation projects that
were part of broader transportation plans implementing SIP
requirements could be approved without further assessments.
EPA argued for additional assessments to evaluate whether
individual projects would affect the attainment of NAAQS in SIP
areas. See, e.g., Letter from Jennifer Joy Wilson, Assistant
Adm’r for External Affairs, EPA & Don R. Clay, Acting
Assistant Adm’r for Air and Radiation, EPA, to Robert E. Farris,
Administrator, Federal Highway Administration, DOT (Nov. 8,
1988).
In 1990, Congress amended the CAA’s conformity
provisions, requiring EPA and DOT jointly to promulgate
transportation regulations. As amended, Section 176(c)(1)3 sets
forth conformity requirements for all activities:
identify transportation “projects” that the MPO wants to implement.
See generally 23 U.S.C. §§ 101 et seq.; 49 U.S.C. §§ 5301 et seq.
3
Section 176(c)(1) provides, in part, that:
No department, agency, or instrumentality of the
Federal Government shall engage in, support in any
way or provide financial assistance for, license or
permit, or approve, any activity which does not
conform to an implementation plan after it has been
approved or promulgated under section 7410 of this
title [addressing SIPs].
42 U.S.C. § 7506(c)(1). MPOs similarly may not approve any
“project, program, or plan which does not conform to a [SIP].” Id.
5
Conformity to an implementation plan means–
(A) conformity to an implementation plan’s purpose of
eliminating or reducing the severity and number of
violations of the national ambient air quality standards
and achieving expeditious attainment of such standards;
and
(B) that such activities will not –
(i) cause or contribute to any new violation of any
standard in any area;
(ii) increase the frequency or severity of any
existing violation of any standard in any area; or
(iii) delay timely attainment of any standard or
any required interim emission reductions or other
milestones in any area.
42 U.S.C. § 7506(c)(1) (emphases added).
The EPA first invoked its authority under § 176(c)(4), 42
U.S.C. § 7506(c)(4), to promulgate regulations applicable to
transportation projects, in 1993. In relevant part, those
regulations required federal agencies and MPOs to conduct an
analysis of the impact of a transportation project upon carbon
monoxide and PM10 pollution at the local level in nonattainment
and maintenance areas. See 40 C.F.R. § 93.101 (1993). Such an
analysis thus provides information concerning pollutant levels
“on a scale smaller than the entire nonattainment or maintenance
area, including, for example, congested roadway intersections .
. . .” Id. The rule required only a qualitative approach for PM10
“until EPA releases [quantitative] modeling guidance on this
subject and announces in the Federal Register that these
requirements are in effect.” Id. §§ 93.131(d), 51.454(d) (1993);
see also id. § 93.123(b)(4).
6
In November 2003 EPA proposed to amend these
conformity regulations by adopting criteria and procedures for
PM2.5 and revising the hot spot rule for PM10. Notice of
Proposed Rulemaking (“NPRM”), 68 Fed. Reg. 62,690, 62, 712
(Nov. 5, 2003). On December 13, 2004, EPA issued a
supplementary proposal setting forth a number of hot spot
options for PM2.5. Supplemental Notice of Proposed Rulemaking
(“Supplemental NPRM”), 69 Fed. Reg. 72,140, 72,144-45 (Dec.
13, 2004), and for PM10, id. at 72,149-50. EPA proposed to
require only a qualitative analysis for PM2.5 in the first instance,
as it had done for PM10. Id. at 72,145.
Ultimately EPA revised the existing hot spot regulation as
regards PM10 and imposed the same criteria for PM2.5. Final
Rule, 71 Fed. Reg. at 12,470-71 (amending 40 C.F.R. § 93.116).
The new hot spot regulation, which applies in nonattainment and
maintenance areas regardless of the SIP, 40 C.F.R. § 93.116,
now provides that a new transportation project:
must not [1] cause or contribute to any new
localized CO, PM10, and/or PM2.5 violations or [2]
increase the frequency or severity of any existing
CO, PM10, and/or PM2.5 violations in CO, PM10
and PM2.5 nonattainment and maintenance areas.
This criterion is satisfied . . . if it is demonstrated
that . . . no new local violations will be created
and the severity or number of existing violations
will not be increased as a result of the project.
Final Rule, 71 Fed. Reg. at 12,510 (codified at 40 C.F.R. §
93.116(a)).
During the rulemaking, Petitioners commented that
proposed § 93.116(a) violated CAA §§ 176(c)(1)(A) and (B)(iii).
They posited that by including only two of the four statutory
7
conformity conditions, the proposed rule failed to require any
finding that the project be consistent with the SIP’s aim of
eliminating all emissions violations and that the project’s
emissions not delay timely attainment and interim progress in
meeting emission milestones. EPA, in response, rejected the
view that the “hot spot” regulation supplants existing
transportation conformity regulations, maintaining instead that
the latter already require transportation projects to be “consistent
with the emissions projections and control measures in the SIP.”
Final Rule, 71 Fed. Reg. at 12,482. According to EPA, the
purpose of “hot spot” regulations is limited to preventing an
increase in the severity or frequency of local violations of
emissions standards, reflecting the mandate of CAA §§
176(c)(1)(B)(i) and B(iii); EPA rejected a construction of CAA
§§ 176(c)(1)(A) and (B)(iii) that would require new individual
projects to reduce emissions as opposed to preventing any new
violations or worsening of existing violations. See id.
EPA also announced in the Final Rule that a previously
established quantitative emissions model, MOBILE6.2, while
potentially appropriate for quantitative analyses of PM2.5 at the
regional level, was not appropriate for PM2.5 or PM10 hot-spot
analyses. Id. at 12,500. Previously, EPA had stated that
MOBILE6.2 “must be used in all PM2.5 conformity analyses,
until [it is] replaced by newer approved methods or models.”
Notice of Availability (“NOA”), 69 Fed. Reg. 28,830, 28,832
(May 19, 2004). Upon releasing MOBILE6.2, EPA had
explained that the release did not trigger any requirement
quantitatively to analyze PM10 emissions under the hot spot rule.
Id.
II.
Petitioners challenge EPA’s amendment to the “hot spot”
conformity regulation, 40 C.F.R. § 93.116, contending that it
8
unlawfully ignores the requirements of CAA §§ 176(c)(1)(A)
and (B)(iii). Petitioners also challenge EPA’s withdrawal of
MOBILE6.2 for PM2.5 hot spot analyses.
A.
As a threshold matter, we hold that insofar as EPA maintains
that Petitioners’ challenge to the Final Rule is time barred
because EPA did not reopen these issues in the rulemaking, its
position is untenable. The final rule applied existing regulatory
criteria to PM10 and PM2.5, and there is a limited period of time
within which an aggrieved party may obtain judicial review of an
EPA rule. In the instant case, however, the notices in the Federal
Register in November 2003 and December 2004 “create[d] the
opportunity for renewed comment [on] and objection” to the “hot
spot” regulation as applied to PM2.5 and PM10. See Ohio v. EPA,
838 F.2d 1325, 1328 (D.C. Cir. 1988). The NPRM “invite[d]
commenters [(sic)] to suggest additional options” for PM10 rules
beyond those EPA proposed. 68 Fed. Reg. at 62,713; see id. at
62,714. The Supplemental NPRM sought comment on the
application of Section 176(c)(1) to PM2.5, stating that “EPA
believes it is important to consider the full range of options for
addressing localized PM2.5 concentrations which may cause or
contribute to any new violation of the PM2.5 standard; increase
the frequency or severity of any existing violation; or delay
timely attainment of the standard.” 69 Fed. Reg. at 72,146.
EPA’s proposed rulemaking, which discussed five different
options, thus explicitly invited comment on the 1993 conformity
rule and the statutory conformity requirements for projects.
Given its expansive call for comments on the “hot spot”
requirements, EPA cannot plausibly contend that Petitioners’
comments asking that the proposed rule be modified for PM2.5
and PM10 raised issues outside the scope of the rulemaking. Nor
did EPA take that position in responding to Petitioners’
9
comments during the rulemaking. Accordingly, the court may
entertain the petition.
B.
When incorporating PM2.5 into the hot spot regulations, EPA
did not require that new projects contribute to reducing the
severity and number of local NAAQS violations, as Petitioners
contend CAA § 176(c)(1)(A) requires, and also did not require
that the new projects not delay the timely attainment of
emissions standards or milestones in any local area, as
Petitioners contend CAA § 176(c)(1)(B)(iii) requires. These
additional statutory conditions are important, Petitioners observe,
because “they add the requirement that the project must
contribute to NAAQS compliance by reducing or eliminating
violations, or that measures must be adopted to ensure that
emissions from the project will not interfere with attainment by
delaying the emission reductions needed for attainment beyond
the attainment deadline.” Petr.’s Br. 20. The two conditions in
the Final Rule “only go so far as to prevent projects that will
worsen existing air quality, either by causing new violations
where none currently exist or by contributing to the increased
frequency or severity of violations being caused by emissions
from an existing highway, terminal or other transportation
facility.” Id. at 20-21. Petitioners further contend that when
Congress amended the CAA in 1990 to prescribe conditions it
removed any agency discretion to define the essential conditions
relevant to making a conformity determination and,
consequently, EPA had no authority to waive its statutory duty
to prescribe criteria and procedures to be used by DOT when
making conformity determinations. Id. at 6-10, 23, 33.
EPA does not dispute that it cannot waive the requirements
of CAA §§ 176(c)(1)(A) and (B), see Final Rule, 71 Fed. Reg. at
12,481; Supplemental NOPR, 69 Fed. Reg. at 72,143, but
reiterates its position in the rulemaking that neither provision of
10
the CAA requires individual projects to reduce emissions, see
Final Rule, 71 Fed. Reg. at 12,481. As construed by EPA, these
provisions “only require air quality to not be worsened by an
individual project than what would have otherwise occurred.”
Id. at 12,482.
We review Petitioners’ challenge to determine whether
EPA’s promulgation of the Final Rule was arbitrary or
capricious, an abuse of discretion, or otherwise not in accordance
with law. See CAA § 307(d)(9)(A), 42 U.S.C. § 7607(d)(9)(A);
see also 5 U.S.C. § 706. Challenges to EPA’s interpretation of
the CAA are governed by the familiar two-pronged test of
Chevron, U.S.A., Inc. v. Natural Resources Defense Council,
Inc., 467 U.S. 837 (1984). Under step one, the court asks
“whether Congress has directly spoken to the . . . issue;” if
Congress’ intent is clear, “that is the end of the matter; for the
court, as well as the agency, must give effect to the
unambiguously expressed intent of Congress.” Id. at 842-43.
However, if the court determines that “Congress has not directly
addressed the precise question at issue,” id. at 843, then, under
step two, “if 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.
1.
Petitioners contend that CAA § 176(c)(1)(A) adds the
additional temporal condition that a project contributes to
attaining the NAAQS “as expeditiously as practicable.” Petr.’s
Br. 21. In support of their interpretation that subsection (A)
requires emissions reductions, Petitioners point to EDF II, 167
F.3d at 647, where the court stated that “a ‘conforming’ . . .
project is one that will contribute to ‘eliminating or reducing the
severity and number of violations of the [NAAQS] . . . .’” Id.
(citing 42 U.S.C. § 7506(c)(1)(A)). We conclude that Petitioners
have not shown that subsection (A) applies to “hot spots” or that
11
EPA’s contrary position is arbitrary or capricious or contrary to
the statute.
Subsection (A) provides that activities shall “conform[] to
an implementation plan’s purpose.” The statute defines an
implementation plan in regional terms by state, not as a localized
area. See CAA § 107(b), 42 U.S.C. § 7407(b). To the extent that
subsection (A), on its face, does not apply to the immediate “area
substantially affected by [a] project,” cf. 40 C.F.R. § 93.101, it
is unnecessary to reach the question of what subsection (A) may
require by way of emissions reduction. But to the extent that
subsection (A) is ambiguous because of the reference in CAA
§ 176(c)(1)’s introductory clause to “project, program, or plan,”
Petitioners fail to show that EPA’s interpretation is not “a
permissible construction of the statute.” Chevron, 467 U.S. at
843.
EPA interprets the conditions in subsection (A) to be “met
if a transportation project is consistent with the emissions
projections and control measures in the SIP.” Final Rule, 71
Fed. Reg. at 12,482. In the preamble to the Final Rule, EPA
explained that “[a]lthough . . . transportation projects need to be
consistent with a SIP’s purpose of reducing violations, this can
be accomplished by simply not increasing violations . . . .” Id.
(citing Envtl. Def. Fund v. EPA (“EDF I”), 82 F.3d 451 (D.C.
Cir. 1996)).4 According to EPA, so long as air quality
concentrations in the entire SIP area are not worsened as the
result of a transportation project, subsection (A) is satisfied.
Consistent with subsection (A)’s focus on the SIP as a whole by
4
EDF I’s interpretation of CAA § 176(c)(1)(A) was recently
reaffirmed by Environmental Defense v. EPA (“EDF III”), 467 F.3d
1329, 1339 (D.C. Cir. 2006), although it too does not speak to the
antecedent question of whether subsection (A) requires a “hot spot”
analysis.
12
contrast with the express attention to “any area” in
§ 176(c)(1)(B), EPA has never taken the position that subsection
(A) applies to a “hot spot.” For example, in the Supplemental
NPRM, EPA cited subsection (B) as the basis for requiring
conformity analysis at PM “hot spots.” See 69 Fed. Reg. at
72,146.
Petitioners view CAA § 176(c)(2) as the statutory scheme
for regional emissions conformity based on the SIP and CAA
§ 176(c)(1) as the scheme for local “hot spot” conformity based
on the NAAQS. Petitioners accordingly assert that EPA has
violated the statute because subsection (A) requires something
different than subsection (B). But Petitioners presuppose that
subsection (A) applies locally without showing that it does.
Although Petitioners correctly note that subsection (A) applies
to ‘any project,’ that does not determine whether a project must
satisfy the conditions in subsection (A) at the local or the
regional level. EPA has taken the latter view, and Petitioners
have not established that its interpretation is contrary to the
statute or unreasonable.
2.
More persuasive is Petitioners’ contention that EPA acted
arbitrarily and contrary to law by not requiring conformity
determinations for individual projects to meet the conditions of
CAA § 176(c)(1)(B)(iii) at the local level. CAA § 176(c)(1)
defines “conformity” as involving “activities” that occur “in any
area” — a phrase that appears in each of subsection (B)’s
subparts. EPA includes in the Final Rule the requirements for
individual projects to comply with the conditions in (B)(i) and
(B)(ii) at the local level, see 40 C.F.R. § 93.101, but does not do
so for (B)(iii)’s conditions. EPA provides no reason for
interpreting “any area” as meaning “a local area,” i.e., “hot
spots,” in (B)(i) and (B)(ii) but not in (B)(iii).
13
EPA maintains on appeal that the Final Rule, along with the
broader regulatory framework and the SIP process can satisfy the
requirements of (B)(iii). Because it interprets the statute not to
require each project to reduce emissions, EPA asserts that it is
not necessary to include (B)(iii)’s conditions in the Final Rule.
See Final Rule, 71 Fed. Reg. at 12,482. However, under EPA’s
revision of the “hot spot” regulations, an individual project’s
emissions could counterbalance mitigation measures already in
place, thereby delaying attainment of emissions standards and
violating the requirement of (B)(iii) without either increasing or
decreasing emissions. EPA’s position thus does not seem to
cover all circumstances where (B)(iii) is applicable.
Even assuming (B)(iii) is ambiguous, EPA’s reliance on the
SIP process would appear to be arbitrary and capricious for
failure to establish “a rational connection between the facts
found and choice made.” Tourus Records, Inc. v. DEA, 259 F.3d
731, 736 (D.C. Cir. 2001) (quotations omitted). In the preamble
to the Final Rule EPA acknowledged that it “does not anticipate
requiring PM2.5 SIP modeling to be performed at a level of detail
that would identify all potential transportation hot spots” and
noted comments by State and Territorial Air Pollution Program
Administrators expressing “concerns regarding the ability of the
SIP to evaluate the local air quality impacts of all future projects
. . . .” Final Rule, 71 Fed. Reg at 12,476. So understood, and in
view of the generous time periods associated with the SIP
process as outlined in EPA’s brief, see Resp.’s Br. at 33, it is
likely that SIP-based enforcement of (B)(iii)’s conditions would
be post-hoc and subject to delays. See, e.g., CAA §§ 110(c) &
(k)(5), 42 U.S.C. §§ 7410(c) & (k)(5). The statutory prohibition
on projects that cause delays in attaining emissions standards
would effectively be stripped of almost any impact and be
inconsistent with Congress’s intent that pollution production be
prevented by forward planning. Thus, even were we to treat the
text as ambiguous, EPA has failed to create a rational link
14
between the requirements of (B)(iii) and the regulatory
framework or the SIP process.
The fundamental problem, however, is that if, as EPA posits
in the Final Rule, “any area” in (B)(i) and (B)(ii) properly means
“a local area” under either Chevron step one or step two, then it
is arbitrary and capricious not to define the term similarly in
(B)(iii) or not to provide an explanation that satisfactorily
addresses the purpose and function of the condition. EPA’s
explanation, that individual projects are not required to reduce
emissions, does not address this inconsistency. A remand is
therefore required for EPA either to interpret (B)(iii) in harmony
with (B)(i) and (B)(ii) or to explain why it need not do so.
3.
Petitioners also contend that EPA erred procedurally when,
without giving adequate notice or soliciting comments, it
declined to require that MPOs and federal agencies perform a
quantitative analysis of PM2.5 emissions at the local level using
MOBILE6.2, a previously approved emissions model.
Petitioners point to EPA’s prior approval of MOBILE6.2 for
such analysis in the 2004 NOA. See 69 Fed. Reg. at 28,832.
EPA responds that judicial review of this procedural issue
is barred because Petitioners did not raise it with “reasonable
specificity” in their comments before the agency. See CAA
§ 307(d)(7)(B), 42 U.S.C. § 7607(d)(7)(B). Notwithstanding our
ordinarily “strict[]” application of CAA § 307(d)(7)(B), see
Motor & Equip. Mfrs. Ass’n v. Nichols, 142 F.3d 449, 462 (D.C.
Cir. 1998), it is inapplicable here. Pursuant to § 307(d)(1)(V), 42
U.S.C. § 7607(d)(1)(V), EPA acted to make CAA § 307(d)
applicable to this rulemaking only upon promulgation of the
Final Rule. See Final Rule, 71 Fed. Reg. at 12,509-10.
Petitioners had no prior notice that EPA would take this step; in
this circumstance CAA § 307(d)(7)(B) does not require that a
15
procedural issue first be presented to the agency. See also Nw.
Envtl. Def. Ctr. v. Bonneville Power Admin., 117 F.3d 1520,
1535 (9th Cir. 1997).
On the merits, however, Petitioners’ contention fails for we
find no procedural error. In the Supplemental NPRM, which
followed the NOA release of MOBILE6.2, EPA provided
sufficient notice and comment opportunities. EPA there
specifically “propose[d] to extend the current rule’s
§ 93.123(b)(3) and (b)(4) requirements with respect to PM2.5.”
Supplemental NPRM, 69 Fed. Reg. at 72,145. Section
93.123(b)(4) then provided that “[t]he requirements for
quantitative analysis [of PM10] will not take effect until EPA
releases modeling guidance on this subject and announces in the
FEDERAL REGISTER that these requirements are in effect.” The
Supplemental NPRM also advised that “[i]f EPA finalizes an
option that would require quantitative and/or qualitative PM2.5
hot spot analyses, we would provide guidance and appropriate
models for carrying out such analyses in a timely manner.” 69
Fed. Reg. at 72,146. Petitioners objected to this proposed delay
in quantitative analysis, noting the previously established
availability of MOBILE6.2 and EPA’s Technical Guidance on
the Use of MOBILE6.2 for Emission Inventory Preparation;
other commentators raised similar objections. EPA responded,
explaining in the preamble to the Final Rule that, in view of its
“technical limitations,” MOBILE6.2 was inappropriate for use in
performing local analyses because it “will produce inaccurate
results in some cases,” which EPA described. Final Rule, 71
Fed. Reg. at 12,499; see also id. at 12,498-502. This exchange
demonstrates that EPA complied with the requirements of notice
and comment rulemaking.
Accordingly, we grant the petition in part and remand the
Final Rule to EPA either to interpret CAA § 176(c)(1)(B)(iii) in
16
harmony with (B)(i) and (B)(ii) or to explain why it need not do
so; we otherwise deny the petition.