Amer Corn Growers v. EPA

United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued February 25, 2002 Decided May 24, 2002

No. 99-1348

American Corn Growers Association,
Petitioner

v.

Environmental Protection Agency,
Respondent

State of Michigan, Department of
Environmental Quality, et al.,
Intervenors

Consolidated with Nos. 99-1349, 99-1350,
99-1351, 99-1352, 99-1357, 99-1358, 99-1359,
01-1111, 01-1112, 01-1113

On Petitions for Review of an Order of the
Environmental Protection Agency

Peter Glaser argued the cause for Industry petitioners and
intervenors on the BART Issues in Case Nos. 99-1348,

99-1349, 99-1350, 99-1351, 99-1352, 99-1356, 99-1357,
99-1358 and 99-1359. With him on the joint briefs were Paul
M. Seby, Henry V. Nickel, F. William Brownell, Michael L.
Teague, Kevin L. Fast, David M. Flannery, Kathy G. Beck-
ett, Scott D. Goldman, Harold P. Quinn, Jr., William H.
Lewis, Jr., and Michael A. McCord.

Kevin L. Fast argued the cause for Industry petitioners in
Case Nos. 01-1111, 01-1112 and 01-1113. With him on the
joint briefs were Peter Glaser, Paul M. Seby, Henry V.
Nickel, F. William Brownell, and Michael L. Teague.

David S. Baron argued the cause and filed the briefs for
petitioner Sierra Club.

Jennifer M. Granholm, Attorney General, State of Michi-
gan, Thomas L. Casey, Solicitor General, and John Fordell
Leone, Assistant Attorney General, were on the briefs for
intervenor State of Michigan.

Pamela S. Tonglao, Kenneth C. Amaditz, and H. Michael
Semler, Attorneys, U.S. Department of Justice, argued the
causes for respondents. With them on the brief was M. Lea
Anderson, Attorney, U.S. Environmental Protection Agency.

Erick Titrud argued the cause for intervenors State of
Maine, State of New Hampshire, State of Vermont, and
Tribal and Environmental intervenors. With him on the joint
brief were Ann Brewster Weeks, Vickie L. Patton, William
G. Grantham, G. Steven Rowe, Attorney General, State of
Maine, Philip T. McLaughlin, Attorney General, State of
New Hampshire, Maureen D. Smith, Senior Assistant Attor-
ney General, and William H. Sorrell, Attorney General, State
of Vermont.

Peter Glaser, Henry V. Nickel, F. William Brownell, Mi-
chael L. Teague, Kevin L. Fast, Paul M. Seby, Harold P.
Quinn, Jennifer M. Granholm, Attorney General, State of
Michigan, John Fordell Leone, Assistant Attorney General,
David M. Flannery, Kathy G. Beckett, William H. Lewis, Jr.,

and Michael A. McCord were on the joint brief for Industry
and State intervenors, in support of respondents.

Mark L. Shurtleff, Attorney General, State of Utah, Fred
Nelson, Assistant Attorney General, and Susan M. McMicha-
el were on the brief for amici curiae State of Utah and State
of New Mexico Environment Department, in support of re-
spondent EPA.

Before: Edwards, Randolph, and Garland, Circuit Judges.

Opinion for the Court filed Per Curiam.

Opinion concurring in part and dissenting in part filed by
Circuit Judge Garland.

Per Curiam: In 1999, the Environmental Protection Agen-
cy promulgated a final rule to address regional haze. See
Regional Haze Regulations, 64 Fed. Reg. 35,714 (July 1,
1999). The Haze Rule calls for states to play the lead role in
designing and implementing regional haze programs to clear
the air in national parks and wilderness areas that have been
classified as "mandatory class I Federal areas,"1 such as
Yellowstone National Park, Grand Canyon National Park, and
Shenandoah National Park. See 40 C.F.R. ss 81.401-.437
(listing areas that have been designated as Class I areas
where visibility is an important value). Numerous petitioners
now challenge the Haze Rule. We vacate the rule in part and
sustain it in part.

I. Introduction

"Regional haze," as EPA defines it, is visibility impairment
caused by geographically dispersed sources emitting fine

__________
1 "Class I" areas include all international parks, national wilder-
ness areas which exceed 5,000 acres in size, national memorial parks
which exceed 5,000 acres in size, and national parks which exceed
6,000 acres in size and which were in existence on August 7, 1977.
See 42 U.S.C. s 7472(a). The term "mandatory class I Federal
areas" is defined as "Federal areas which may not be designated as
other than class I." Id. s 7491(g)(5). At the time the Haze Rule
was promulgated, there were 156 Class I areas across the country.
See 64 Fed. Reg. at 35,714.

particles and their precursors into the air. See 64 Fed. Reg.
at 35,715. The emission and movement of sulfur dioxide,
oxides of nitrogen, and fine particulate matter from sources,
such as power plants, contribute to haze. See id. Fine
particulate matter scatters and absorbs light. See id.

Haze has degraded visibility in most of the country's na-
tional parks and wilderness areas. See id. The average
visual range in many Class I areas in the western United
States is 100 to 150 kilometers - which is just one-half to two-
thirds the estimated visual range that would exist without
manmade air pollution. See id. In most of the eastern
United States, the average visual range is less than 30
kilometers - or about one-fifth the visual range that would
exist under estimated natural conditions. See id.

Before 1977, the Clean Air Act (the "CAA" or the "Act")
"did not elaborate on the protection of visibility as an air-
quality related value." Chevron U.S.A., Inc. v. EPA, 658
F.2d 271, 272 (5th Cir. 1981). But in 1977, "[i]n response to a
growing awareness that visibility was rapidly deteriorating in
many places, such as wilderness areas and national parks," id.
at 272, Congress added s 169A to the Act. See Clean Air Act
Amendments of 1977, Pub. L. No. 95-95, s 128, 91 Stat. 685,
742 (current version at 42 U.S.C. s 7491). Section 169A
established as a national goal the "prevention of any future,
and the remedying of any existing, impairment in visibility in
mandatory class I areas which impairment results from man-
made air pollution." See 91 Stat. at 742 (current version at 42
U.S.C. s 7491(a)(1)). Congress directed EPA to issue regula-
tions requiring states to submit State Implementation Plans
("SIPs") containing emission limits, schedules of compliance,
and other measures necessary to make reasonable progress
toward meeting the national visibility goal. See 91 Stat. at
743 (current version at 42 U.S.C. s 7491(b)(2)). In addition,
Congress required states to address possible visibility impair-
ment caused by currently-operating large stationary sources
which had been in operation between 1962 and 1977. See 91
Stat. at 743 (current version at 42 U.S.C. s 7491(b)(2)(A)).

 Congress also gave EPA the responsibility of promulgating
regulations under s 169A to "assure ... reasonable progress
toward meeting the national goal." See 91 Stat. at 742-43
(current version at 42 U.S.C. s 7491(a)(4)). EPA issued its
first regulations in 1980. See 45 Fed. Reg. 80,084 (Dec. 2,
1980). The 1980 visibility regulations, which apply to states
containing at least one Class I area, addressed visibility
impairment reasonably attributable to one source, or to a
small number of sources. See id. at 80,085. EPA limited the
reach of the 1980 regulations to impairment attributable to
specific sources and deferred any action on regional haze
attributable to multiple sources located across broad geo-
graphic regions because there was insufficient data regarding
the relationship between emitted pollutants, pollutant trans-
port and visibility impairment. See id. at 80,086.

In 1990, Congress amended the Clean Air Act again, add-
ing s 169B in an attempt to prompt EPA to further address
visibility impairment in national parks and wilderness areas.
See Clean Air Act Amendments, Pub. L. No. 101-549, s 816,
104 Stat. 2695 (1990) (current version at 42 U.S.C. s 7492).
Section 169B requires, among other things, that EPA under-
take research to identify "sources" and "source regions" of
visibility impairment in Class I areas, consider designating
transport commissions to study the interstate movement of
pollutants, and establish a transport commission for the
Grand Canyon National Park. See 42 U.S.C. s 7492.

EPA established the Grand Canyon Visibility Transport
Commission ("GCVTC") in 1991 to assess information about
the adverse impacts on visibility in and around sixteen Class I
areas on the Colorado Plateau region and to provide policy
recommendations to EPA to address such impacts. See 56
Fed. Reg. 57,522 (Nov. 12, 1991). The GCVTC issued its
report to EPA in 1996. Then in 1997 EPA issued a notice of
proposed rulemaking with regard to regional haze, see 62
Fed. Reg. 41,138 (July 31, 1997), noting that advances in
scientific and technical knowledge, including analyses provid-
ed by the GCVTC, had made it possible for EPA to target
region-wide visibility impairment. After receiving more than
1,300 comments to the proposed rule, EPA published the final

Haze Rule on July 1, 1999. See 64 Fed. Reg. at 35,714. The
final Haze Rule reaches all states because, EPA concluded, all
states contain sources whose emissions are "reasonably antici-
pated to contribute to regional haze in a Class I area." Id. at
35,721. Under the Haze Rule, a state must develop and
submit a SIP that provides for reasonable progress toward
achieving "natural visibility conditions" in the national parks
and wilderness areas in that state. See 40 C.F.R.
s 51.308(d)(1). SIPs addressing regional haze in an "attain-
ment" area must be submitted within one year of the date the
area is designated as "attainment," and revised SIPs for
"non-attainment" areas must be submitted within three years
after the designation. See id. s 51.308(b)(1)-(2).

The Haze Rule, for the most part, does not specify what
control measures a state must implement in its initial SIP.
See 64 Fed. Reg. at 35,721 (noting that the determination of
what specific control measures must be implemented "can
only be made by a State once it has conducted the necessary
technical analyses of emissions, air quality, and the other
factors that go into determining reasonable progress"). But
the rule does require states to: (1) provide for an improve-
ment in visibility in the 20 percent most impaired days; (2)
ensure that there is no degradation in visibility during the 20
percent clearest days; and (3) determine the annual rate of
visibility improvement that would lead to "natural visibility"
conditions in 60 years. See 40 C.F.R. s 51.308(d)(1); see also
id. s 51.301; 64 Fed. Reg. at 35,734. A state may not adopt
a rate of improvement that would achieve natural visibility
conditions in more than 60 years unless it demonstrates that
the 60-year rate is unreasonable. See 40 C.F.R.
s 51.308(d)(1)(ii).

The Haze Rule also provides that each state must develop a
long-term strategy for achieving its visibility improvement
goals. This strategy must include the identification of all
major stationary sources subject to Best Available Retrofit
Technology ("BART") requirements. See id. s 51.308(e). In
identifying sources subject to BART, the Haze Rule calls for
states to use a group rather than a source-by-source ap-
proach. See 64 Fed. Reg. at 35,740 (providing that a state
should find a source subject to BART "if it can be shown that

the source emits pollutants within a geographic area from
which pollutants can be emitted and transported downwind to
a Class I area") (italics added). In addition, when establish-
ing emission limits for BART sources, states must consider
the improvement in visibility that would result if the technolo-
gy were used at all comparable BART sources (rather than
the improvement that a particular device at a particular
source would accomplish). See 40 C.F.R. s 51.308(e)(1)(ii)(B).

The various petitioners and intervenors in this consolidated
case raise numerous challenges to the Haze Rule. In Part II
we address the claim that EPA acted contrary to law in
establishing a group rather than a source-by-source approach
to BART determinations. In Part III we address the claims
of industry petitioners in Case Nos. 01-1111, 01-1112, and
01-1113 that EPA acted without legal authority and in anarbi-
trary and capricious manner in promulgating the "natural
visibility" goal and the "no degradation" requirement in the
regional haze regulations. Finally, in Part IV, we address
the challenges raised by the Sierra Club - namely that EPA
failed to set reasonable criteria for measuring or assuring
reasonable progress, and that EPA acted contrary to law in
extending the statutory deadline for submission of state haze
control plans.

II. BART Issues

Under s 169A of the Act, each state must review all
BART-eligible sources - meaning all major stationary sources
built between August 1962 and August 1977 - to determine
whether the sources emit "any air pollutant which may rea-
sonably be anticipated to cause or contribute to any impair-
ment of visibility" in a Class I area.2 42 U.S.C.
s 7491(b)(2)(A). After deciding that a BART-eligible source
emits a pollutant which may reasonably be anticipated to

__________
2 A "major stationary source" is a source that has the potential
to emit 250 tons or more of any pollutant. See 42 U.S.C.
s 7491(g)(7).

cause or contribute to Class I visibility impairment, the state
then must determine what is the best available retrofit tech-
nology for controlling emissions from that source. See id.
Under the Act, states must take the following five factors into
consideration when deciding what BART controls to place on
a source:

the costs of compliance, the energy and nonair quality
environmental impacts of compliance, any existing pollu-
tion control technology in use at the source, the remain-
ing useful life of the source, and the degree of improve-
ment in visibility which may reasonably be anticipated to
result from the use of such technology.

Id. s 7491(g)(2).

The Haze Rule interprets and implements these statutory
BART provisions in two main ways. First, the Haze Rule
requires states to "find that a BART-eligible source is 'rea-
sonably anticipated to cause or contribute' to regional haze if
it can be shown that the source emits pollutants within a
geographic area from which pollutants can be emitted and
transported downwind to a Class I area." 64 Fed. Reg. at
35,740 (italics added). In other words, states must subject
BART-eligible sources to BART requirements even absent
empirical evidence of that source's individual contribution to
visibility impairment in a Class I area so long as the source is
located within a region that may contribute to visibility
impairment. See id. at 35,740; see also Br. for EPA at 26-27.
EPA explained in the preamble to the Haze Rule that this
sort of "collective contribution" approach was "consistent with
that taken in the programs for acid rain and ozone, programs
which also address regional air quality problems caused by
transported pollutants." 64 Fed. Reg. at 35,740; see also 63
Fed. Reg. at 57,376.

Second, the Haze Rule provides that once a state has
decided that a particular source is subject to BART and is
considering what BART controls to place on that source, the
state must analyze "the degree of visibility improvement that
would be achieved in each mandatory Class I Federal area as
a result of the emission reductions achievable from all sources

subject to BART located within the region that contributes to
visibility impairment in the Class I area." 40 C.F.R.
s 51.308(e)(1)(ii)(B) (italics added). This means that of the
five statutory factors to be considered by states when deter-
mining BART controls, see 42 U.S.C. s 7491(g)(2), only four
factors (the costs of compliance, the environmental impacts of
compliance, any existing pollution control technology in use at
the source, and the remaining useful life of the source) are
considered on a source-specific basis. The Haze Rule re-
quires states to consider the fifth statutory factor (the degree
in improvement) on a group or "area wide" basis.

Industry petitioners attack EPA's decision to use a group
rather than a source-by-source BART approach, arguing that
the language, statutory structure, and legislative history of
s 169A make it clear that the Haze Rule runs afoul of the
Act. See Br. for Industry Pet'rs and Intervenor in Case Nos.
99-1348, et al. at 13. For the reasons that follow, we grant
the petition for review, vacate the BART rules, and remand
to EPA.

In the Haze Rule, EPA extracts one of the five statutory
factors listed in s 169A(g)(2) and treats it differently than the
other four. See 64 Fed. Reg. at 35,741 (providing that only
"the degree in improvement in visibility that would be expect-
ed at each Class I area as a result of imposing BART" is to
be considered on a group rather than a source-specific basis).
In effect, EPA bifurcates the states' determination of the
appropriate BART emission limitations for specific sources.
States must first estimate possible emission reductions on a
source-by-source basis based on the application of the tech-
nology, the cost, time for compliance, energy and nonair
environmental impacts, and the remaining useful life of the
source. See id.; see also 40 C.F.R. s 51.308(e)(1)(ii)(A).
"Taking these factors into account allows the State to arrive
at an estimate of the 'best system' of retrofit control technolo-
gy for a particular source." 64 Fed. Reg. at 35,741. States
must then calculate the degree in improvement in visibility
that would be expected at each Class I area as a result of

imposing BART on all sources subject to BART. See id.; see
also 40 C.F.R. s 51.308(e)(1)(ii)(B).

EPA argues that its bifurcated approach to determining
appropriate BART controls is permissible because
s 169A(g)(2) is unclear about how a state must analyze
anticipated visibility improvement. See Chevron U.S.A., Inc.
v. Natural Res. Def. Council, 467 U.S. 837, 842-43 (1984).
We cannot agree. The Haze Rule's splitting of the statutory
factors is consistent with neither the text nor the structure of
the statute. See 42 U.S.C. s 7491(g)(2). All five
s 169A(g)(2) factors inform the states' inquiries into what
BART controls are appropriate for particular sources. Al-
though no weights were assigned, the factors were meant to
be considered together by the states. The language of
s 169A(g)(2) can be read in no other way. To treat one of
the five statutory factors in such a dramatically different
fashion distorts the judgment Congress directed the states to
make for each BART-eligible source. This is most apparent
with respect to the states' duty to take into account "the costs
of compliance" in deciding not only whether to order an
individual source to install any new pollution control equip-
ment, but also what type of equipment - or as the statute
puts it, what type of "retrofit technology." How is a state to
determine what is too costly (and what is not) for a particular
source? The statute answers that the state must consider the
degree of improvement in visibility in national parks and
wilderness areas that would result from the source's installing
and operating the retrofit technology. EPA has a far differ-
ent answer: in assessing the cost of compliance imposed on a
source, the state may not consider the degree to which new
equipment at a particular source would help cure the haze in
some distant national park. Under EPA's take on the stat-
ute, it is therefore entirely possible that a source may be
forced to spend millions of dollars for new technology that
will have no appreciable effect on the haze in any Class I
area.3 A similar problem arises when a state considers, as it

__________
3 EPA's rule requires states to consider the cost of compliance
in terms of the likely emission reductions which would be achieved

must, the "existing pollution control technology in use at the
source." How is a state to decide whether the source already
has installed sufficient devices without determining how
much, if at all, the source is contributing to visual impairment
in downwind Class I areas? As the industry petitioners
correctly note, there is no point during the Haze Rule's
BART determination "in which it could be demonstrated that
the degree of improvement in visibility obtained from install-
ing a particular set of emissions controls at a source with
'exceedingly low' or even merely theoretical visibility impacts
is not justified by the cost of BART in light of those low or
theoretical impacts." Br. for Industry Pet'rs and Intervenor
in Case Nos. 99-1348, et al. at 17-18.

The Haze Rule's treatment of s 169A(g)(2)'s degree-of-
improvement calculation is, the industry petitioners argue,
not the only respect in which the rule is inconsistent with the
Act. As they see it, the Haze Rule also unlawfully constrains

__________
by the imposition of BART, no matter whether this reduction would
enhance visibility in downwind national parks. See 64 Fed. Reg. at
35,741 (explaining that the four factors, including cost, "should be
taken into account for each source subject to BART in order to
compare tradeoffs between the control efficiencies and costs associ-
ated with various control alternatives"). The preamble to the rule
provides very little guidance about how states are to calculate the
degree of improvement in visibility under the regime EPA contem-
plates. The preamble tells the states only this:

To calculate the degree of improvement in visibility that would
be expected at each Class I area as a result of imposing BART
on all sources subject to BART, the State should estimate the
possible emissions reductions resulting from the application of
BART at all subject sources located within the region that
contributes to visibility impairment in the Class I area. The
State should work on its own or in conjunction with other
States, such as a regional planning body, to determine the
geographic scope of the region that contributes to each Class I
area. The States should consult with one another to determine
the emission reductions achievable from sources subject to
BART in other states.

Id.

the states' statutory authority because under the Act it is the
states - not EPA - who must determine which BART-eligible
sources should be subject to BART. See 42 U.S.C.
s 7491(b)(2)(A) (providing that each BART-eligible source
that, "as determined by the State ... emits any air pollutant
which may reasonably be anticipated to cause or contribute to
any impairment of visibility," shall install and operate the
best available retrofit technology (italics added)); see also id.
s 7491(g)(2) (listing the factors that "the State ... shall take
into consideration" in determining BART controls (italics
added)).

We agree with these petitioners that the Haze Rule's
BART provisions are inconsistent with the Act's provisions
giving the states broad authority over BART determinations.
See id. s 7491(b)(2)(A); see also id. s 7491(g)(2). The Haze
Rule ties the states' hands and forces them to require BART
controls at sources without any empirical evidence of the
particular source's contribution to visibility impairment in a
Class I area. See 64 Fed. Reg. at 35,740; see also Br. for EPA
at 26-27. If the Haze Rule contained some kind of a mecha-
nism by which a state could exempt a BART-eligible source
on the basis of an individualized contribution determination,
then perhaps the plain meaning of the Act would not be
violated. But the Haze Rule contains no such mechanism.
Section 169A(c)(1) - on which EPA relies - is a procedure by
which the Administrator, with the approval of federal land
managers, can exempt a source from BART requirements.
See 42 U.S.C. s 7491(c)(1) ("The Administrator may, by rule,
after notice and opportunity for public hearing, exempt any
major stationary source from [the BART requirements], upon
his determination that such source does not or will not, by
itself or in combination with other sources, emit any air
pollutant which may reasonably be anticipated to cause or
contribute to a significant impairment of visibility in any
mandatory class I Federal area."); see also id. s 7491(c)(3).
It does not provide the states with a means by which they can
exempt sources based on individual contribution determina-
tions.

 Our conclusion that the Haze Rule's BART provisions
impermissibly constrain state authority is reinforced by the
Conference Report on the 1977 amendments to the Act. See
Demby v. Schweiker, 671 F.2d 507, 510 (D.C. Cir. 1981). The
Report explains:

The agreement clarifies that the State, rather than the
Administrator, identifies the source that impairs visibility
in the Federal class I areas identified....

In establishing emission limitations for any source which
impairs visibility, the State shall determine what consti-
tutes "best available retrofit technology" ... in establish-
ing emission limitations on a source-by-source basis to be
included in the State implementation plan so as to carry
out the requirements of this section.

H.R. Conf. Rep. No. 95-564 (1977), reprinted in 3 Senate
Comm. on Env't and Pub. Works, A legislative History of the
Clean Air Act Amendments of 1977, at 535 (1978) [hereinafter
"1977 Legislative History"]. The "agreement" to which the
Conference Report refers was an agreement to reject the
House bill's provisions giving EPA the power to determine
whether a source contributes to visibility impairment and, if
so, what BART controls should be applied to that source.
See id. at 533-35. Pursuant to the agreement, language was
inserted to make it clear that the states - not EPA - would
make these BART determinations. See id. at 533-35; see
also H.R. Res. 4151, 95th Cong. (1977), reprinted in 1977
Legislative History at 1985, 2325-30. The Conference Report
thus confirms that Congress intended the states to decide
which sources impair visibility and what BART controls
should apply to those sources. The Haze Rule attempts to
deprive the states of some of this statutory authority, in
contravention of the Act.

In sum, we conclude that the Haze Rule's BART provisions
are contrary to the text, structure and history of s 169A of
the Act because the rule isolates s 169A(g)(2)'s benefit calcu-
lation and constrains authority Congress conferred on the
states. Although petitioners also contended that no concept
of a group or area-wide BART determination could ever be

consistent with the Act,4 we need not decide that broad issue
today. We hold only that the Haze Rule's treatment of
s 169A(g)(2)'s benefit calculation and its infringement on
states' authority under the Act render the BART provisions
of the rule impermissible.

III. The "Natural Visibility" Goal and the
"No Degradation" Requirement

The industry petitioners in Case Nos. 01-1111, 01-1112, and
01-1113 ("Reconsideration Petitioners") cite four grounds in
support of their claim that the "natural visibility" goal and the
"no degradation" requirement in the Haze Rule should be
vacated as "arbitrary and capricious" and otherwise not in
accordance with law: (1) EPA exceeded its authority under
s 169A(a)(1) and adopted regulations that conflict with the
PSD program in establishing "natural visibility" as the goal of
the regional haze program; (2) the regulations impermissibly
constrain state discretion in requiring that the states develop
their visibility programs using the "no degradation" require-
ment as a bench mark; (3) EPA has no authority to impose
upon the states the goal of achieving "natural visibility"
conditions, and thereby restrict the opportunity of some
states to participate in the planning process aimed at address-
ing regional haze; and (4) EPA promulgated the Haze Rule
without providing adequate notice and an opportunity for
comment. We find no merit in these claims and, accordingly,
deny industry petitioners' challenge to the "natural visibility"
goal and the "no degradation" requirement.

__________
4 The industry petitioners argued that source-by-source BART
determinations are required by the statute and that no concept of
area-wide BART determinations is permissible. See Brief for In-
dustry Pet'rs and Intervenor in Case Nos. 99-1348, et al. at 14
(arguing that s 169A makes it clear that BART determinations
"must be made on a source-by-source basis"). Cf. Train v. Natural
Res. Def. Council, 421 U.S. 60, 64 (1975) (discussing the history of
the Clean Air Act and how the premise of the Act was to give states
and local governments responsibility over preventing air pollution
"at its source").

 Before we turn to the merits of petitioners' claims, we must
first address EPA's contentions that petitioners' challenge to
the natural visibility goal and their claims of inadequate
notice are barred because they were not properly raised
before the agency. We find no merit in EPA's contentions.
Petitioners argued that the Haze Rule conflicted with the
PSD program in both their comments to the agency before
the regulations were issued and in their petition for reconsid-
eration. See Supplemental Comments of the Utility Air
Regulatory Group at 22, reprinted in Joint Appendix ("J.A.")
156; Petition for Reconsideration of the Regional Haze Regu-
lations Submitted by Utility Air Regulatory Group & Nation-
al Mining Ass'n at 10-11, reprinted in J.A. 97-98. Petitioners
also sought notice and comment in connection with these
portions of the Haze Rule in their petition for reconsideration.
See Petition for Reconsideration of the Regional Haze Rule
Submitted by the Center for Energy and Economic Develop-
ment at 11-14, reprinted in J.A. 116-19.

On the merits, we reject petitioners' claim that EPA had no
authority under s 169A to adopt the natural visibility goal.
EPA acted under express congressional authorization in pro-
mulgating the challenged regulations. See 42 U.S.C.
s 7491(a)(4). In a case such as this, where

"there is an express delegation of authority to the agency
to elucidate a specific provision of the statute by regula-
tion," Chevron, 467 U.S. at 843-844, ... any ensuing
regulation is binding in the courts unless procedurally
defective, arbitrary or capricious in substance, or mani-
festly contrary to the statute.

United States v. Mead Corp., 533 U.S. 218, 227 (2001) (foot-
note omitted). The natural visibility goal is neither "mani-
festly contrary to the statute" nor "arbitrary or capricious in
substance." Indeed, the goal is an eminently reasonable
elucidation of the statute.

The statutory goal enunciated in s 169A(a)(1) is quite clear:
"the prevention of any future, and the remedying of any
existing, impairment of visibility." 42 U.S.C. s 7491(a)(1).
Petitioners argue that a "natural visibility" goal cannot be

gleaned from this statutory standard. This claim is specious.
Agency regulations that aim to remedy any existing impair-
ment of visibility and prevent any future impairment - as the
statute commands - will of necessity aim to achieve a state of
natural visibility. There is no material inconsistency between
the statutory and regulatory goals, for the latter merely
elucidates the former.

The petitioners also claim that Congress did not intend for
the statutory goal of s 169A(a) to displace the objectives of
the PSD program. Therefore, according to petitioners, the
natural visibility goal and the no degradation requirement
cannot be squared with the PSD program, because that
program recognizes that some impairment of visibility would
be acceptable in Mandatory Federal Class I areas. We reject
this argument, because EPA has reasonably construed the
PSD program and the disputed regional haze rules as comple-
mentary regulatory regimes.

There are two things worth noting at the outset. First, the
natural visibility goal is not a mandate, it is a goal. As EPA
has explained, this goal serves as the foundation for analytical
tools to be used by the states to set reasonable progress
goals. 64 Fed. Reg. at 35,732-33 Petitioners' claim that the
agency is without authority to mandate attainment of the
national goal is therefore meritless.

Second, the statute specifically calls for regulations to
assure "reasonable progress toward meeting the national
goal" of remedying any current and preventing any future
impairment of visibility. 42 U.S.C. s 7491(a)(4). The no
degradation provision requires implementation plans to "pro-
vide for an improvement in visibility for the most impaired
days over the period of the implementation plan and ensure
no degradation in visibility for the least impaired days over
the same period." 40 C.F.R. s 51.308(d)(1). This regulation
plainly and permissibly serves to assure the reasonable prog-
ress sought by Congress.

The PSD program was adopted pursuant to the 1977
amendments to the Act. See generally Ala. Power Co. v.
Costle, 636 F.2d 323, 349-51 (D.C. Cir. 1979). The program

generally controls any additional deterioration of air quality
by establishing maximum allowable increases of certain pollu-
tants in specified areas. See 42 U.S.C. s 7473(b). It is
therefore true, as industry petitioners point out, that the PSD
program may sometimes allow for limited air quality deterio-
ration. EPA, however, has taken pains to explain that the
PSD program and the Haze Rule are not at odds:

Section 169A of the CAA requires the EPA to promul-
gate regulations to ensure that the States revise their
implementation plans to contain those measures neces-
sary to make reasonable progress toward the national
visibility goal. In addition to the remedying of any
existing visibility impairment, that goal requires the pre-
vention of any future visibility impairment in mandatory
Class I Federal areas. As part of the overall strategy to
effectuate that goal, the final rule requires States to
identify all anthropogenic sources of visibility impair-
ment. The States accordingly should take into account
the cumulative effect of all existing, man-made sources of
air pollution in developing their regional haze implemen-
tation plan as well as potential new sources.

With respect to the comment that EPA lacks authority
to impose a welfare-based standard which renders other
requirements of the CAA such a[s] PSD and NSPS
largely superfluous, EPA notes that when Congress
amended the CAA in 1977 to provide for the protection of
visibility, it was aware of both the PSD and NSPS
provisions. Nevertheless, Congress required EPA to
issue regulations to address visibility. In contrast, the
final regional haze rule requires States to take into
account the visibility impact of emissions from both
existing and new sources, and stationary and nonstation-
ary sources. This is only one of many instances under
the CAA in which Congress has provided for overlapping
regulation. Indeed, the PSD and NSPS programs both
focus on the control of emissions from new stationary
sources. EPA believes that the regional haze rule and
these other provisions are complementary means of im-
proving air quality.

 Commenters raised a number of specific questions
regarding the interaction of the PSD program and the
regional haze rule. One commenter asked the EPA to
address the relationship of allowable Class I impacts to
the proposed visibility impact limits. All PSD areas are
categorized as Class I, II, or III. The classification of an
area determines the corresponding maximum allowable
increases, or increment, of air quality deterioration.
Only a relatively small increment of air quality deteriora-
tion is permissible in Class I areas. These increments
are measured over annual, 24-hour, and/or 3-hour aver-
aging times. Nowhere, however, does the CAA provide
that air quality must be allowed to deteriorate to the full
extent allowed by the Class I increments standing alone.
To read the statute in that manner would contravene
both the general goals of the CAA to "protect and
enhance" air quality (see section 101(b)(1)) but the specif-
ic long-term goal of section 169A is to eventually remedy
existing visibility impairment in Class I areas. Accord-
ingly, we believe that allowing localized air quality in-
creases in the short-term due to the emissions from
major new sources subject to PSD is not inconsistent
with the regional haze program. The regional haze
program is focused on long-term emission decreases from
the entire regional emission inventory, comprised of ma-
jor and minor stationary sources, area sources and mo-
bile sources. We expect that long-term emission strate-
gies for regional haze will derive substantial emission
decreases from the inventory as a whole, and that these
overall strategies will be able to accommodate some
localized increases within the framework of a regional
decrease. We also note that the overall inventory would
decrease in cases where new sources are built that
replace older, more polluting sources. Accordingly, we
do not see any inherent conflict between the two pro-
grams.

While the PSD program generally allows for a small
increment of air quality deterioration in Class I areas,
section 165 of the CAA also provides for the additional

 protection of air quality-related values, "including visibili-
ty," in Class I Federal areas beyond that provided by the
increments. That is, where the FLM [Federal Land
Manager] demonstrates that emissions from a new or
modified source will have an adverse impact on air
quality-related values (AQRVs), notwithstanding the fact
that the emissions from the source do not cause or
contribute to concentrations in excess of the increment
for a Class I area, "a permit shall not be issued."
Section 165(d). Thus, under PSD there can be no in-
crease in emissions from the construction or modification
of a major stationary source where that increase would
result in adverse impacts on AQRVs in a Class I Federal
area.

Responses to Significant Comments on the Notice of Pro-
posed Rulemaking s I.F (Apr. 1999), reprinted in J.A. 1062-
63.

The Government also reminds us that the PSD program
"does not require that [visibility] deterioration occur. Nor
does it create an entitlement to degrade air quality in general
or visibility in particular, because nothing in the CAA pro-
vides for issuance of a PSD permit as a matter of right." Br.
for EPA at 59. We agree.

Petitioners cite Alabama Power in an attempt to support
their claim that the existence of the PSD program effectively
bars "natural visibility" as a viable regulatory goal. Alabama
Power supports no such claim. Indeed, the court noted that
"[s]ection 169A is available to protect visibility in Class I
areas where visibility is an important characteristic, and the
[agency] may choose to invoke [its] rulemaking authority ...
to address this problem." 636 F.2d at 368. In acknowl-
edging the availability of s 169A, the court implicitly em-
braced EPA's view that the visibility program is a supplement
to the PSD program.

Industry petitioners additionally claim that the no degrada-
tion requirement conflicts with s 169A(g)(1)'s list of factors
that states must consider when determining reasonable prog-
ress. Section 169A(g)(1) states:

 in determining reasonable progress there shall be taken
into consideration the costs of compliance, the time nec-
essary for compliance, and the energy and nonair quality
environmental impacts of compliance, and the remaining
useful life of any existing source subject to such require-
ments.

42 U.S.C. s 7491(g)(1). Petitioners argue that, because "rea-
sonable progress" could at times involve degradation, the "no
degradation" requirement restricts the States' authority to
apply the statutory criteria. We disagree.

As noted above, the statute commands EPA to promulgate
regulations assuring "reasonable progress toward meeting
the national goal." Id. s 7491(a)(4). The national goal in-
cludes "the prevention of any future ... impairment of
visibility." Id. s 7491(a)(1). The no degradation require-
ment simply elucidates "reasonable progress." The require-
ment does not, however, in any way alter the list of
s 169A(g)(1) criteria. In fact, the cited statutory factors do
not include "degradation." Therefore, the States will be able
to comply with the no degradation requirement while apply-
ing the s 169A(g)(1) criteria.

Next, although the petitioners assert that the Haze Rule
somehow restricts the opportunity of some states to partici-
pate in the planning process aimed at addressing regional
haze, we can find no real evidence in support of this claim.
This contention certainly offers no ground upon which to
vacate the disputed regulations.

Finally, petitioners claim that they did not have fair notice
and an adequate opportunity to comment on the regulatory
goal of natural visibility, because "EPA provided no notice in
its 1997 proposal that it intended to require States to achieve
natural visibility conditions." Br. for Reconsideration Pet'rs
at 25. Rather, according to petitioners, EPA merely pro-
posed regulations patterned on the statutory goal enunciated
in s 169A(a)(1), i.e., "'preventing any future, and remedying
any existing, impairment of visibility."' Br. for Reconsidera-
tion Pet'rs at 25 (quoting old 40 C.F.R. s 51.300(a)(1)). This
argument is meritless. As noted above, there is no material

inconsistency between the statutory goal enunciated in
s 169A(a)(1) and the regulatory goal of "natural visibility."
The latter is a "logical outgrowth" of the former. Fertilizer
Inst. v. EPA, 935 F.2d 1303, 1311 (D.C. Cir. 1991). There-
fore, EPA did not violate any notice and comment require-
ments in adopting the natural visibility goal as a part of the
Haze Rule.

If there is any tension between the Haze Rule and the PSD
program, it is EPA's responsibility to harmonize the regulato-
ry requirements. It has done so in a perfectly reasonable
fashion. EPA's regulatory harmonization is both consistent
with the statute and reasonable. Accordingly, we deny the
petitions for review of the natural visibility goal and the no
degradation requirement.

IV. The "Reasonable Progress" Criteria and
the Extension of the Statutory Deadline

While the Industry Petitioners attack the Regional Haze
Rule as overstepping EPA's statutory authority, Sierra Club
argues that EPA has not gone far enough to meet its
statutory responsibilities.

In its first cluster of attacks on the Haze Rule, Sierra Club
contends that the Rule does not satisfy EPA's responsibility
under CAA s 169A(a)(4) to "promulgate regulations to assure
... reasonable progress toward meeting the national [visibili-
ty] goal," 42 U.S.C. s 7491(a)(4), its responsibility under CAA
s 169B(e)(1) to establish "criteria for measuring 'reasonable
progress' toward the national goal," 42 U.S.C. s 7492(e)(1),
and its obligation under the Administrative Procedure Act not
to act in an "arbitrary or capricious" fashion, 5 U.S.C. s 706
(2)(A). Sierra Club argues that the Haze Rule's require-
ments for improvement in visibility during the 20 percent
most impaired days and for no degradation during the 20
percent least impaired days, 40 C.F.R. s 51.308(d)(1); see
also 64 Fed. Reg. at 35,734, do not qualify as "reasonable
progress" criteria and are arbitrary and capricious. Similar-
ly, it argues that the Rule's requirement that a state not
adopt a rate of improvement that would take more than 60
years to achieve natural visibility unless the state demon-

strates that the 60-year rate is unreasonable, 40 C.F.R.
s 51.308(d)(1)(i)(b), (ii), does not meet the statutory mandates
and lacks "requisite specificity" because a state would be
"free to reject the 60 year time frame merely by claiming that
such a schedule is not 'reasonable."' Reply Br. for Sierra
Club at 5, 8.

We might well consider the latter attack unripe even
without reference to our decision in Part II that the group-
BART provisions of the Haze Rule are invalid. If in the
future a state does conclude that it needs more than 60 years
to achieve natural visibility, and if EPA decides to accept that
conclusion, it will at that time be open to Sierra Club to
challenge EPA's decision as arbitrary and capricious. In the
meantime, this court will certainly "'benefit from postponing
review until the policy in question has sufficiently crystal-
lized."' Grand Canyon Air Tour Coalition v. FAA, 154 F.3d
455, 472 (D.C. Cir. 1998) (quoting Florida Power & Light Co.
v. EPA, 145 F.3d 1414, 1421 (D.C. Cir. 1998)).

But in any event, our decision to invalidate the group-
BART provisions renders this entire cluster of challenges
unripe for disposition. Because those provisions were inti-
mately related to EPA's assessment of what was necessary to
achieve the goal of natural visibility, we cannot be sure
whether on remand EPA will retain its current criteria for
evaluating reasonable progress or adopt others. If the invali-
dation of the group-BART provisions causes EPA to doubt
the efficacy of the remaining elements of the Haze Rule,
perhaps EPA will see wisdom in some of Sierra Club's
complaints and, for example, increase the percentage of days
during which there must be improvement in visibility, or
increase the specificity of its criteria for reasonable progress.
In light of the uncertainty that our decision creates with
respect to the form of the rule that may emerge upon
remand, the only prudent course is for us to decline to
address Sierra Club's challenges at this juncture.

Sierra Club's second major attack on the Haze Rule chal-
lenges EPA's determination to give states 3 years to file haze
SIPs for areas designated "attainment" or "unclassifiable."
We are troubled by EPA's action, which appears to contra-

vene express statutory language, but in light of our decision
regarding group-BART we leave this to EPA to reconsider on
remand as well.

The Transportation Equity Act for the 21st Century, Pub.
L. No. 105-178, 112 Stat. 107, 463 (1998) ("TEA-21"), provides
that, for areas designated as "nonattainment" for the new
national ambient air quality standard (NAAQS) for fine par-
ticulate matter, EPA shall require states to submit haze SIPs
3 years after the area has been so designated. See TEA-21
s 6102(c)(2) (incorporating the 3-year deadline of 42 U.S.C.
s 7492(e)(2)). However, TEA-21 also expressly mandates
that for any area designated as "attainment" or "unclassifia-
ble" for that standard, EPA "shall require the [SIP] to be
submitted 1 year after the area has been so designated." Id.
Nonetheless, the Haze Rule permits a state to "choose to
defer addressing the [Rule's] core requirements for regional
haze ... and the requirements for BART" by submitting a
so-called "commitment SIP," containing a "demonstration of
ongoing participation in a regional planning process to ad-
dress regional haze, and an agreement ... to continue partic-
ipating," a "description of the regional planning process," and
a "list of all BART-eligible sources within the state." 40
C.F.R. s 51.308(c), (c)(1). If a state submits such a commit-
ment SIP, the deadline for submitting a haze SIP is extended
from 1 year to 3. Id. s 51.308(c)(2); see Br. for EPA at 87;
Br. for Sierra Club at 25.

On its face, this provision of the Haze Rule appears to
extend the express statutory deadline for "attainment" and
"unclassifiable" areas, an action which is beyond the agency's
authority. See Sierra Club v. EPA, 129 F.3d 137, 140 (D.C.
Cir. 1997) (holding that EPA cannot establish a "grace peri-
od" for compliance when not authorized to do so by the CAA);
Sierra Club v. EPA, 719 F.2d 436, 469 (D.C. Cir. 1983)
(reversing an EPA implementation plan that would have
effectively extended the statutory deadline for state submis-
sions under CAA amendments). The statute requires states
to submit, by the 1-year deadline, SIPs "contain[ing] such
emission limits, schedules of compliance, and other measures
as may be necessary to carry out" the haze regulations. 42

U.S.C. s 7492(e)(2) (incorporated by reference into TEA-21
s 6102(c)(2)). A commitment SIP, which by definition ad-
dresses neither the Haze Rule's "core requirements for re-
gional haze," nor its "requirements for BART," 40 C.F.R.
s 51.308(c), does not appear to satisfy the statutory require-
ment. Cf. Natural Res. Def. Council, Inc. v. EPA, 22 F.3d
1125, 1134 (D.C. Cir. 1994) (holding, under CAA s 110(k)(4),
that EPA cannot satisfy its responsibility to determine wheth-
er a state plan submission complies with the CAA unless the
submission "contains something more than a mere promise to
take appropriate but unidentified measures in the future,"
and that a submission containing nothing more than such a
commitment cannot extend the statutory deadline).

Notwithstanding our doubts about the validity of this provi-
sion, we decline to vacate it in light of the uncertainty that
our decision invalidating the group-BART provisions of the
Haze Rule will cast upon the contents of the SIPs required of
the states. With the Rule and hence the contents of the SIPs
now altered and subject to revision on remand, the more
prudent course for this court is simply to remand the dead-
line-extension issue as well. This will permit the agency to
reconsider its decision to extend the deadline at the same
time that it decides what form the substantive requirements
of a revised Haze Rule should take.

 Garland, Circuit Judge, concurring in part and dissenting
in part: In the Clean Air Act, Congress declared a national
goal of restoring natural visibility in the country's largest
national parks and wilderness areas. In Part II of today's
opinion, the court adopts an interpretation of the Act that, in
the view of the Environmental Protection Agency (EPA) and
the National Academy of Sciences, will prevent the achieve-
ment of Congress' goal. If that interpretation were required
by the statutory language, we would of course be compelled
to adopt it. But such an interpretation is not required. To
the contrary, EPA's construction of the Clean Air Act as
permitting the group-BART provisions of the Haze Rule is a
reasonable interpretation of the legislative language. It is
therefore entitled to our deference under the standard an-
nounced in Chevron U.S.A. Inc. v. Natural Res. Def. Council,
Inc., 467 U.S. 837, 842-43 (1984). Accordingly, while concur-
ring in most of the court's opinion, I dissent from the
conclusions it reaches in Part II.

A

Chevron instructs courts to apply a two-step framework
when reviewing an agency's construction of a statute. First,
we must ask "whether Congress has directly spoken to the
precise question at issue," in which case we "must give effect
to the unambiguously expressed intent of Congress." Id. at
842-43. However, if the "statute is silent or ambiguous with
respect to the specific issue," we move to the second step and
must defer to the agency's interpretation as long as it is
"based on a permissible construction of the statute." Id. at
843; accord Barnhart v. Walton, 122 S.Ct. 1265, 1271-72
(2002).

My colleagues stop at Chevron's first step, concluding that
the language of the Clean Air Act (CAA) can be read in only
one way. They adopt the view of the industry petitioners
that under the Act, BART ("best available retrofit technolo-
gy") controls cannot be imposed on a source unless a state
determines how much that particular source contributes to
visual impairment in a downwind national park or wilderness
area, as well as how much improvement in visibility would
result from installing BART controls at that specific source.
Op. at 10-11. EPA, by contrast, interprets the Clean Air Act

as permitting a collective assessment of the impact that
emissions from (and controls on) sources located in upwind
regions have on visibility impairment in downwind areas.

Before considering the grounds for the court's decision, it is
important to understand why EPA decided to require a
collective contribution approach, rather than a tracing of the
effects of each individual source's emissions. Congress added
s 169A to the Clean Air Act "[i]n response to a growing
awareness that visibility was rapidly deteriorating" in major
national parks and wilderness areas ("Class I areas"). Chev-
ron U.S.A., Inc. v. EPA, 658 F.2d 271, 272 (5th Cir. 1981).
The section establishes a national goal of restoring natural
visibility in such areas,1 and expressly instructs EPA to issue
regulations to "assure ... reasonable progress" toward meet-
ing the national goal. 42 U.S.C. s 7491(a)(4). After examin-
ing the results of scientific studies, EPA concluded that such
reasonable progress was not possible without a collective
approach. The record compiled by EPA showed that visibili-
ty impairment in Class I areas is caused in large part by
long-range transport of combined emissions from multiple
sources.2 Although it is practicable to trace emissions from
an individual source into its surrounding region, and to model
the transport of combined pollution from that region to a
downwind Class I area,3 it is not possible to trace emissions

__________
1 Section 169A declares the national goal to be "the prevention
of any future, and the remedying of any existing, impairment of
visibility in mandatory class I Federal areas." 42 U.S.C.
s 7491(a)(1). As the court holds today, agency regulations that aim
to accomplish these objectives "will of necessity aim to achieve a
state of natural visibility." Op. at 16.

2 See, e.g., Congressional Research Service, Regional Haze:
EPA's Proposal to Improve Visibility in National Parks and
Wilderness Areas 2 (1997) (J.A. at 242); National Academy of
Sciences, National Research Council, Protecting Visibility in
National Parks and Wilderness Areas 7-8, 196-99 (1993) (J.A. at
362, 456-57) [hereinafter "NAS Report"].

3 See Regional Haze Regulations, 64 Fed. Reg. 35,714, 35,718
(July 1, 1999). The court does not dispute the reasonableness of, or

from an individual source directly to such a downwind area
without great time and expense4--and even then the results
would be of uncertain reliability.5 Citing the National Acade-
my of Sciences' conclusion that a program focused "on deter-
mining the contribution of individual emission sources to
visibility impairment is doomed to failure,"6 EPA adopted the
group-BART approach that is at issue here.

__________
support for, the latter proposition. Cf. Appalachian Power Co. v.
EPA, 135 F.3d 791, 802 (D.C. Cir. 1998) (noting that "computer
models are a useful and often essential tool for performing the
Herculean labors Congress imposed on EPA in the Clean Air Act,"
and that "their scientific nature does not easily lend itself to judicial
review" (internal quotation marks omitted)); id. at 814 ("[O]ur
consideration of EPA's use of computer models proceeds with
considerable deference to the agency's expertise.").

4 See NAS Report at 240-41 (J.A. at 478) ("It would be ex-
tremely time-consuming and expensive to try to determine the
percent contribution of individual sources to haze one source at a
time."); Regional Haze Regulations, 64 Fed. Reg. at 35,740 ("[E]s-
tablishing the contribution from one particular source to the prob-
lem of regional haze would require lengthy and expensive studies
and pose substantial technical difficulties.").

5 See NAS Report at 2 (J.A. at 359) ("During transport, the
emissions from many sources mix together to form a uniform,
widespread haze known as regional haze."); id. at 20 (J.A. at 368)
("[T]he extent to which [source-specific] techniques can be used in
attributing visibility impairment is uncertain, as is their usefulness
in estimating the effect that different control strategies might have
on visibility."); id. at 25-26 (J.A. at 370-71) ("Efforts to decide
whether a particular source is contributing to regional haze have
thus far encountered grave obstacles. Studies designed to estimate
the effect of a particular source on surrounding visibility are
expensive, and the results can be uncertain and controversial."). To
take just one example, "the efforts to trace the contribution of the
Navajo Generating Station to haze in the Grand Canyon National
Park took several years and cost millions of dollars without leading
to quantitatively definitive answers." Id. at 7 (J.A. at 361).

6 EPA, Resp. to Pets. for Recons. of Regional Haze Rule 16
(Jan. 10, 2001) (J.A. at 17) (quoting NAS Report at 7 (J.A. at 361));

My colleagues do not dispute that we must defer to EPA's
expert opinion regarding the impracticability of tracing indi-
vidual source emissions.7 Rather, they conclude that notwith-
standing EPA's view of the facts, the industry petitioners are
correct that the Haze Rule's group-BART provisions violate
the plain meaning of the Clean Air Act by: (i) employing a
group rather than source-by-source standard in determining
the appropriate BART controls for a particular source, and
(ii) constraining the authority of the states to make their own
BART-related decisions. These two contentions are consid-
ered in Parts B and C below. Because I conclude that there
is nothing in the Clean Air Act that bars the approach taken
by EPA, and that to the contrary the Haze Rule rests on a
reasonable interpretation of the statutory language, I would
follow the Supreme Court's direction in Chevron and uphold
the Rule.

B

As the court notes, the Haze Rule employs a group analysis
in making two determinations required by the Clean Air Act:
(i) whether a pollution-emitting source is subject to BART
requirements at all, and (ii) what kind of BART controls
should be placed on a subject source. The industry petition-
ers contend that the Clean Air Act prohibits the use of a
group standard in making either of these determinations.

Under the Act, a source is subject to BART requirements,
and hence a state implementation plan must require such a
source to install BART controls, if it "emits any air pollutant
which may reasonably be anticipated to cause or contribute to
any impairment of visibility in any [Class I] area." CAA

__________

see also NAS Report at 240 (J.A. at 478) ("The committee doubts
... that such attributions could be the basis for a workable visibility
protection program.").

7 See Appalachian Power, 135 F.3d at 801-02 ("Our analysis is
guided by the deference traditionally given to agency expertise,
particularly when dealing with a statutory scheme as unwieldy and
science-driven as the Clean Air Act."); see also Husqvarna AB v.
EPA, 254 F.3d 195, 199 (D.C. Cir. 2001).

s 169A(b)(2)(A), 42 U.S.C. s 7491(b)(2)(A). Under the Haze
Rule, a state must "find that a BART-eligible source is
'reasonably anticipated to cause or contribute' to regional
haze if it can be shown that the source emits pollutants within
a geographic area from which pollutants can be emitted and
transported downwind to a Class I area." Regional Haze
Regulations, 64 Fed. Reg. at 35,740. That is, a source is
subject to BART requirements, without proof of that source's
individual contribution to visibility impairment in a Class I
area, as long as the source emits pollutants into an upwind
area from which pollutants may be transported to a down-
wind Class I area. Id.

The industry petitioners contend that CAA s 169A(b)(2)
unambiguously provides that a source is subject to BART
requirements only if a state can show the extent to which that
particular source contributes to impairment in a Class I area.
That section, however, requires states to impose BART con-
trols on any source that "emits any air pollutant which may
reasonably be anticipated to cause or contribute to any
impairment of visibility in any [Class I] area." 42 U.S.C.
s 7491(b)(2)(A) (emphasis added). Far from plainly compel-
ling the petitioners' reading, the italicized words pile ambigui-
ty upon ambiguity and virtually invite the reader to adopt the
construction favored by EPA. See Merriam-Webster's Col-
legiate Dictionary 252 (10th ed. 1996) (defining "contribute"
as "to give or supply in common with others," or "to give a
part to a common ... store") (emphasis added); Central
Ariz. Water Conservation Dist., 990 F.2d 1531, 1541 (9th Cir.
1993) ("The phrase 'may reasonably be anticipated' suggests
that Congress did not intend to require EPA to show a
precise relationship between a source's emissions and all or a
specific fraction of the visibility impairment within a Class I
area." (quoting with approval National Research Council,
Haze in the Grand Canyon: An Evaluation of the Winter
Haze Intensive Tracer Experiment 5 (1990))). If a source is
one of several that emit pollutants into an upwind area, and if
pollution from that area is transported downwind to a nation-

al park,8 then it can hardly be unreasonable to conclude that
the pollutants issued by the source "may reasonably be
anticipated" to "contribute" to "any" impairment in the park.

My colleagues wisely do not accept the industry petitioners'
contention that s 169A(b)(2) bars a collective determination
of whether a source is subject to BART. (As discussed in
Part C infra, they do conclude that EPA may not require the
states to employ such a mode of analysis.) They do, however,
accept the petitioners' contention that to determine the kind
of BART controls that should be imposed on a subject source,
a state must determine how much that particular source
contributes to visual impairment in the downwind Class I
area, Op. at 11, as well as the degree of improvement in
visibility that would occur in the downwind area if that
particular source installed such controls, id. at 10. The Haze
Rule, by contrast, provides that once a state has concluded
that a particular source is subject to BART requirements, in
determining the kind of BART controls to place on the source
the state must consider the degree of improvement that
would be achieved in the downwind area by imposing BART
controls on all subject sources in the contributing upwind
area. See 40 C.F.R. s 51.308(e)(1)(ii)(B); Regional Haze
Regulations, 64 Fed. Reg. at 35,741.

The industry petitioners rest their contention that the
statute unambiguously bars this collective assessment ap-
proach on s 169A(g)(2), which states:

[I]n determining best available retrofit technology the
State ... shall take into consideration [1] the costs of
compliance, [2] the energy and nonair quality environ-
mental impacts of compliance, [3] any existing pollution
control technology in use at the source, [4] the remaining
useful life of the source, and [5] the degree of improve-

__________
8 Under the Haze Rule, the state must establish the first
condition directly and the second through the application of comput-
er modeling techniques. See Regional Haze Regulations, 64 Fed.
Reg. at 35,740, 35,741; supra note 3.

 ment in visibility which may reasonably be anticipated to
result from the use of such technology.

42 U.S.C. s 7491(g)(2). According to both the industry peti-
tioners and the court, this section requires the state to take
into consideration each of the five listed factors on a source-
by-source basis. Since the Haze Rule does require source-
by-source consideration of the first four factors, see Regional
Haze Regulations, 64 Fed. Reg. at 35,740-41; Op. at 9, the
only question is whether such consideration is also required of
the fifth factor: "the degree of improvement in visibility
which may reasonably be anticipated to result from the use of
such technology."

There is nothing in the statutory language that requires a
source-by-source application of the fifth factor. Section
169A(g)(2) requires an assessment of the degree of improve-
ment that may reasonably be anticipated "from the use of
such technology," but it does not say whether that improve-
ment must be from the use of such technology by a single
source or by all sources in the upwind area.9 Although the
court says that the statute does not permit any of the five
factors to be treated differently from any of the others, the
statute itself does not say so. Moreover, the first four factors
are different in kind from the fifth: the first four all go to the
cost of imposing controls on a particular source and permit a
determination of the most cost-effective control technology
for each such source. Regional Haze Regulations, 64 Fed.
Reg. at 35,740-41. The fifth factor, by contrast, goes to the
benefit to be derived from using the most cost-effective
controls. In EPA's expert view, that benefit can best be
determined by considering the total benefit that would accrue
if each source in the upwind area used the kind of controls
most cost-effective for that source.

The industry petitioners concede that s 169A(g)(2) does not
require a state to undertake a cost-benefit analysis in decid-
ing the type of controls to impose, or specify the weight to be

__________
9 See Regional Haze Regulations, 64 Fed. Reg. at 35,741 ("EPA
interprets the language 'from the use of such technology' to refer to
the application of BART level controls to all sources subject to
BART.").

accorded to any of the five factors.10 All that is required is
that the state "take into consideration" the five listed factors.
42 U.S.C. s 7491(g)(2). Because the statute does not specify
how the state should take those factors into consideration, it
does not bar EPA from employing a group rather than
source-by-source mode of analysis in considering benefits.
See Weyerhaeuser Co. v. Costle, 590 F.2d 1011, 1045 (D.C.
Cir. 1978) (holding that where "Congress did not mandate any
particular structure or weight" for the factors EPA is to
consider, "it left EPA with discretion to decide how to account
for the consideration factors, and how much weight to give
each factor"); see also New York v. Reilly, 969 F.2d 1147,
1150 (D.C. Cir. 1992) (same).

Other related provisions of the Clean Air Act support
EPA's reading of s 169A(g)(2) as permitting a region-wide
assessment. Section 169A(a)(3) directs EPA to undertake a
study to "identify the classes or categories of sources ...
which, alone or in conjunction with other sources ..., may
reasonably be anticipated to cause or contribute significantly
to impairment of visibility," 42 U.S.C. s 7491(a)(3) (emphasis
added), and s 169A(b)(1) directs that the regulations promul-
gated under s 169A take into account the recommendations
of that study, 42 U.S.C. s 7491(b)(1). Similarly, s 169B(a)(1)
instructs EPA to conduct research "to identify and evaluate
sources and source regions of ... visibility impairment." 42
U.S.C. s 7492(a)(1) (emphasis added); see id. s 7492(a)(2).
These provisions not only permit, but again appear to invite a
group-BART approach.

The court states that "under EPA's take on the statute, it
is ... entirely possible that a source may be forced to spend

__________
10 Reply Br. for Industry Pet'rs at 8 ("Industry Petitioners
agree ... that states are free to determine the weight and signifi-
cance to be assigned to each of the CAA s 169A(g)(2) factors."); see
Op. at 10; cf. American Textile Mfrs. Inst., Inc. v. Donovan, 452
U.S. 490, 510 (1981) ("When Congress has intended that an agency
engage in cost-benefit analysis, it has clearly indicated such intent
on the face of the statute."); Central Ariz., 990 F.2d at 1542 n.10
(holding that "Congress has not required 'cost-benefit' analysis in
the [Clean Air] Act").

millions of dollars for new technology that will have no
appreciable effect on the haze in any Class I area." Op. at
10. In accordance with the statute, however, EPA has struc-
tured the Haze Rule to avoid this result. The Rule creates
an evidentiary presumption that, if a source emits pollution
into an upwind region from which it can be shown that
pollution is transported downwind to a Class I area, then it
"may reasonably be anticipated" that the source "cause[s] or
contribute[s] to" impairment in the Class I area--and hence
that limiting the source's emissions will reduce that impair-
ment.11 But the presumption is not irrebuttable. To the
contrary, the Haze Rule incorporates the exemption provision
of s 169A(c)(1), which permits EPA to

exempt any major stationary source from the [BART]
requirement of subsection (b)(2)(A) of this section, upon
his determination that such source does not or will not,
by itself or in combination with other sources, emit any
air pollutant which may reasonably be anticipated to
cause or contribute to a significant impairment of visibili-
ty in any mandatory class I Federal area.

__________
11 The court does not dispute the reasonableness of this pre-
sumption. See American Iron & Steel Inst. v. EPA, 115 F.3d 979,
1000 (D.C. Cir. 1997) (holding that it is reasonable for EPA to
presume that if a pollutant is present in fish tissue at a level
exceeding that set by regulation, then any facility "that contributes
a pollutant to a body of water [in which the fish swims] ... has the
reasonable potential to contribute to that exceedence"); see also
Baltimore Gas & Elec. Co. v. Natural Res. Def. Council, Inc., 462
U.S. 87, 103 (1983) (holding that a reviewing court must be "at its
most deferential" when the agency is "making predictions, within its
area of special expertise, at the frontiers of science"); American
Trucking Ass'ns, Inc. v. EPA, 175 F.3d 1027, 1055 (D.C. Cir. 1999)
("[W]e have expressly held that EPA's decision to adopt and set air
quality standards need only be based on reasonable extrapolations
from some reliable evidence." (internal quotation marks omitted)),
rev'd on other grounds sub nom. Whitman v. American Trucking
Ass'ns, Inc., 531 U.S. 457 (2001).

42 U.S.C. s 7491(c)(1); see also 40 C.F.R. ss 51.303,
.308(e)(4). Hence, a source that emits pollution into a source
region, but that can show that BART controls are unneces-
sary because its pollution does not contribute to a significant
impairment of visibility in a Class I area, will not have to
spend money installing BART controls.12 All that the Haze
Rule does is put the burden of proof on the polluter, rather
than on the state. Moreover, the statute's limitation of the
exemption to a source that does not by itself "or in combina-
tion with other sources" contribute to a significant impair-
ment, 42 U.S.C. s 7491(c)(1), once again invites the collective-
assessment approach taken by EPA.

Finally, one more provision of s 169A deserves repeat
mention here. As discussed in Part A above, s 169A(a)(4)
instructs EPA "to promulgate regulations to assure reason-
able progress toward meeting the national goal" of restoring
natural visibility conditions. 42 U.S.C. s 7491(a)(4). Yet
EPA's findings indicate that it will not be possible "to assure
reasonable progress" if the statutory interpretation an-
nounced today prevails: it is simply not practicable to deter-
mine, as the court's interpretation requires, how much a
particular "source is contributing to visual impairment in
downwind Class I areas," or the degree of improvement in
visibility in such areas "that would result from [a particular]
source's installing and operating" BART controls. Op. at 11,
10; see supra notes 4, 5. Indeed, EPA explained that it
"avoided inclusion of any approach in the regional haze rule
that required the assessment of the visibility improvement
attributed to an individual source because" the National
Academy of Sciences had determined that such an approach
was "doomed to failure." Resp. to Pets. for Recons. of

__________
12 The court correctly notes that under this exemption, it is
EPA rather than the state that determines whether a source has
made the required showing. EPA, however, does not rely on the
exemption to answer the state-authority issue discussed in Part C
below, but rather to counter the petitioners' claim that the Haze
Rule fails to provide a source with the opportunity to demonstrate
that it makes no appreciable contribution to visibility impairment in
a Class I area. Br. for EPA at 29-30, 32.

Regional Haze Rule 16 (Jan. 10, 2001) (J.A. at 17) (quoting
National Academy of Sciences, National Research Council,
Protecting Visibility in National Parks and Wilderness
Areas 7-8, 196-99 (1993) (J.A. at 362, 456-57)). We should
not lightly assume that Congress enacted a statute that
makes it impracticable to achieve the same statute's stated
goal. There certainly is nothing in the language of the Clean
Air Act that requires us to adopt such a self-defeating
construction.

C

The industry petitioners' second attack on the Haze Rule
marches under the banner of states' rights, but in this case
that banner is a false flag. The Rule gives states great
leeway to make the BART determinations required by the
Clean Air Act, reserving to EPA no more authority than
Congress conferred upon the agency. Moreover, as discussed
above, the industry petitioners' insistence that both EPA and
the states are barred from using group-BART principles will
impose an enormous unfunded mandate on the states--re-
quiring them to engage in lengthy, expensive, and likely
fruitless studies to trace pollutants from specific sources into
specific Class I areas.13 It is not surprising, therefore, that
only a single state has enlisted under the petitioner's banner.
Five others have filed briefs in support of EPA, while the
balance remain silent.

The industry petitioners attack, as unlawfully constraining
state authority, both the provision of the Haze Rule that
concerns which sources are subject to BART requirements,
and the provision that concerns the kind of BART controls
that must be installed on subject sources. With respect to
the former, the petitioners emphasize s 169A's declaration
that "each major stationary source ... which, as determined
by the State ... emits any air pollution which may reasonably

__________
13 See supra notes 4, 5; Br. for Maine, et al. at 10 (protesting
that to adopt the industry petitioners' interpretation of s 169A(g)(2)
"would impose staggering and costly administrative burdens" on the
states).

be anticipated to cause or contribute to any impairment of
visibility" in a Class I area, is subject to BART requirements.
42 U.S.C. s 7491(b)(2)(A) (emphasis added). With respect to
the latter, they stress that s 169A requires that each subject
source install "the best retrofit technology, as determined by
the State," 42 U.S.C. s 7491(b)(2)(A), and that "in determin-
ing best available retrofit technology the State ... shall take
into consideration" the five factors discussed in Part B above,
id. s 7491(g)(2) (emphasis added). By directing the states to
employ a group-BART analysis in making these determina-
tions, the industry petitioners contend, and the court agrees,
that EPA has unlawfully constrained the states' decisionmak-
ing authority. Op. at 11-13.

The Haze Rule, however, does not contravene the statutory
commands italicized above. Under the Rule, it is the state
and not EPA that determines which specific sources emit
pollution that "may reasonably be anticipated to cause or
contribute to" impairment, and hence are subject to BART
requirements. All that EPA has done, as explained in Part
B, is reasonably interpret that phrase to include sources that
emit pollution into upwind regions from which pollution is
transported to national parks. It is still the state that must
determine both that the source emits covered pollutants, and
that the region into which the source emits such pollutants is
one from which emissions may reasonably be anticipated to
be transported to downwind parks. See 40 C.F.R.
s 51.308(e)(1)(ii); Regional Haze Regulations, 64 Fed. Reg. at
35,739-41; Br. for EPA at 43. Similarly, it is still the state
that must take into consideration the five statutory factors
and the state that must then determine the best available
retrofit technology for a particular source. All that EPA has
done, again as explained in Part B, is reasonably interpret the
fifth of those factors to require the state to analyze the
degree of anticipated improvement on a group basis. See
Regional Haze Regulations, 64 Fed. Reg. at 35,741.

Moreover, the Clean Air Act expressly delegates to EPA
the authority to make these kinds of judgments. As already
noted, s 169A directs EPA to promulgate regulations to

assure reasonable progress toward meeting the national goal
of restoring natural visibility. 42 U.S.C. s 7491(a)(4). It
further instructs that those regulations shall "provide guide-
lines to the States ... on appropriate techniques and meth-
ods for implementing" the section's provisions, including the
provisions governing which sources are subject to BART
requirements and the kind of BART controls that should be
imposed. Id. s 7491(b)(1). The section likewise directs EPA
to "require each applicable implementation plan for a State
... to contain such emission limits, schedules of compliance
and other measures as may be necessary to make reasonable
progress toward meeting the national goal" of restoring natu-
ral visibility. Id. s 7491(b)(2). Similarly, the next section of
the Act, s 169B, orders EPA to "carry out [its] regulatory
responsibilities" under s 169A by promulgating "criteria for
measuring 'reasonable progress' toward the national goal."
42 U.S.C. s 7492(e)(1). These provisions give EPA ample
authority to promulgate guidelines requiring states to use
group-BART principles to determine both the sources that
are subject to BART requirements and the kinds of controls
those sources must install.

My colleagues contend that the Conference Report on the
1977 Clean Air Amendments reinforces their view that the
Haze Rule impermissibly constrains state authority. Op. at
13. But that report is a weak reed upon which to rest a
Chevron step one claim regarding the Act's plain meaning.
As the court recounts, the report merely states that the
conference "agreement clarifies that the State, rather than
the Administrator, identifies the source that impairs visibili-
ty," and that in determining the appropriate BART controls
for such a source, "the state shall determine what constitutes
'best available retrofit technology' ... in establishing emis-
sion limitations on a source-by-source basis." H.R. Conf.
Rep. No. 95-564, at 535 (1977). The report tells us nothing
more about the referenced "agreement" than can be gleaned
from these quotations, and the quotations themselves do little
more than restate the statutory language. Moreover, as
noted above, the Haze Rule is consistent with these quota-
tions: under the Rule, it is the state rather than EPA that

identifies the sources that impair visibility, and it is the state
that determines the best available retrofit technology for each
such individual source. All that the group-BART provisions
of the Rule do is effectuate EPA's authority to "provide
guidelines to the states" for making these determinations
regarding particular sources. 42 U.S.C. s 7491(b)(1).14

As the Clean Air Act repeatedly declares, restoring natural
visibility to national parks and wilderness areas is a "nation-
al" goal. See id. s 7491(a)(1), (a)(4), (b)(2), (b)(2)(B); id.
s 7492(e)(1). It is not surprising, therefore, that while the
Act leaves many determinations regarding particular sources
to the states, it grants EPA authority to establish national
guidelines for the kind of analysis the states must employ in
making those determinations.15 Under the statute, those
guidelines must "assure ... reasonable progress toward
meeting the national goal" of restoring natural visibility. Id.
s 7491(a)(4). Because EPA has reasonably determined that
group-BART principles are necessary to provide such assur-
ance, the provisions of the Haze Rule that incorporate those

__________
14 The court states that the "agreement" referred to in the
report was an agreement to reject the provisions of an earlier
House bill. As there may have been many reasons for rejecting
that bill, the "[r]ejection of [the] proposed legislation during the
course of enactment provides a hazardous basis from which to
determine legislative intent," GAO v. GAO Pers. Appeals Bd., 698
F.2d 517, 525 n.52 (D.C. Cir. 1983), and a particularly hazardous
foundation for a Chevron step one claim. In any event, the most
the court can divine regarding the content of the agreement is that
it was to insert language clarifying that the states were to "deter-
mine whether a source contributes to visibility impairment and, if
so, what BART controls should be applied to that source." Op. at
13. As noted in the text, the Haze Rule leaves both determinations
in the hands of the states.

15 Cf. Appalachian Power Co. v. EPA, 249 F.3d 1032, 1047
(D.C. Cir. 2001) (holding that a state's development of its implemen-
tation plan under CAA s 110 is not "free of extrinsic legal con-
straints," including EPA's reasonable construction of CAA s 126).

principles are a permissible exercise of the agency's delegated
power.

D

In sum, there is nothing in the language, structure or
history of the Clean Air Act that bars EPA from promulgat-
ing the group-BART provisions of its Haze Rule. To the
contrary, those provisions represent "a reasonable interpreta-
tion of an ambiguous statute," and therefore must be given
effect by this court. Christensen v. Harris County, 529 U.S.
576, 586 (2000) (citing Chevron, 467 U.S. at 842-844). Ac-
cordingly, I respectfully dissent from the court's decision to
strike down those provisions.