Petition for Writ of Certiorari — Environmental Protection Agency, et al., Petitioners v. Kentucky, et al.

No. XX-XX

In the Supreme Court of the United States

ENVIRONMENTAL PROTECTION AGENCY, ET AL.

PETITIONERS

v.

COMMONWEALTH OF KENTUCKY, ET AL.

ON PETITION FOR A WRIT OF CERTIORARI

TO THE UNITED STATES COURT OF APPEALS

FOR THE SIXTH CIRCUIT

PETITION FOR A WRIT OF CERTIORARI

SARAH M. HARRIS

Acting Solicitor General

Counsel of Record

ADAM R.F. GUSTAFSON

Acting Assistant Attorney

General

MALCOLM L. STEWART

Deputy Solicitor General

AIMEE W. BROWN

Assistant to the Solicitor

General

JEFFREY HAMMONS

Attorney

Department of Justice

Washington, D.C. 20530-0001

SupremeCtBriefs@usdoj.gov

(202) 514-2217

QUESTION PRESENTED

The United States Environmental Protection Agency

(EPA) took a final action under the Clean Air Act, 42

U.S.C. 7401 et seq., to disapprove 21 States’ plans for implementing national ozone standards. EPA determined

that those state plans would not adequately “prohibit[]

* * * emissions activity within the State” from “contribut[ing] significantly to nonattainment in, or interfer[ing] with maintenance by, any other State” of national ambient air quality standards.

42 U.S.C.

7410(a)(2)(D)(i)(I). The question presented is as follows:

Whether EPA’s disapproval action is subject to review only in the D.C. Circuit under 42 U.S.C. 7607(b)(1),

which channels to that court petitions to review EPA final actions that are “nationally applicable” or are “based

on a determination of nationwide scope or effect.”

(I)

PARTIES TO THE PROCEEDING

Petitioners in this Court are the United States Environmental Protection Agency, which was the respondent in the court of appeals in Nos. 23-3216 and 23-3225,

and Lee Michael Zeldin, Administrator of the Environmental Protection Agency.*

Respondents in this Court are the Commonwealth of

Kentucky, which was the petitioner in the court of appeals in No. 23-3216, and the Kentucky Energy and Environment Cabinet, which was the petitioner in the

court of appeals in No. 23-3225.

RELATED PROCEEDINGS

United States Court of Appeals (6th Cir.):

Kentucky v. EPA, No. 23-3216 (Dec. 6, 2024)

Kentucky Energy & Env’t Cabinet v. EPA, No. 233225 (Dec. 6, 2024)

Pursuant to this Court’s Rule 35.3, Lee Michael Zeldin is automatically substituted for his predecessor, Michael Regan, who was

the respondent in the court of appeals in Nos. 23-3216 and 23-3225.

*

(II)

TABLE OF CONTENTS

Page

Opinion below ................................................................................ 1

Jurisdiction .................................................................................... 1

Statutory provisions involved ...................................................... 2

Statement ...................................................................................... 2

Reasons for granting the petition ............................................... 7

Conclusion ..................................................................................... 8

Appendix A — Court of appeals opinion

(Dec. 6, 2024) ................................................ 1a

Appendix B — Statutory provisions ..................................... 59a

TABLE OF AUTHORITIES

Case:

EPA v. EME Homer City Generation, L.P.,

572 U.S. 489 (2014)................................................................ 3

Statutes:

Administrative Procedure Act,

5 U.S.C. 551 et seq., 701 et seq. ............................................ 7

Clean Air Act, 42 U.S.C. 7401 et seq. ..................................... 2

Tit. I .................................................................................... 2

42 U.S.C. 7408 .................................................................... 3

42 U.S.C. 7409 .................................................................... 3

42 U.S.C. 7410(a) ....................................................... 3, 59a

42 U.S.C. 7410(a)(2)(D)(i)(I) ..................................... 3, 60a

42 U.S.C. 7410(c)(1) ................................................... 3, 68a

42 U.S.C. 7410(k)(2) .................................................. 3, 77a

42 U.S.C. 7410(k)(3) .................................................. 3, 77a

42 U.S.C. 7607(b)(1) .............................................. 2, 4, 6, 7

Miscellaneous:

76 Fed. Reg. 48,208 (Aug. 8, 2011) ......................................... 3

(III)

IV

Miscellaneous—Continued:

Page

80 Fed. Reg. 65,292 (Oct. 26, 2015) ........................................ 3

88 Fed. Reg. 9336 (Feb. 13, 2023) ...................................... 4, 5

In the Supreme Court of the United States

No. XX-XX

ENVIRONMENTAL PROTECTION AGENCY, ET AL.,

PETITIONERS

v.

COMMONWEALTH OF KENTUCKY, ET AL.

ON PETITION FOR A WRIT OF CERTIORARI

TO THE UNITED STATES COURT OF APPEALS

FOR THE SIXTH CIRCUIT

PETITION FOR A WRIT OF CERTIORARI

The Acting Solicitor General, on behalf of the Environmental Protection Agency (EPA) and Lee Zeldin,

Administrator of the EPA, respectfully petitions for a

writ of certiorari to review the judgment of the United

States Court of Appeals for the Sixth Circuit in this

case.

OPINION BELOW

The opinion of the court of appeals (App., infra, 1a-58a)

is reported at 123 F.4th 447.

JURISDICTION

The judgment of the court of appeals was entered on

December 6, 2024. The jurisdiction of this Court is invoked under 28 U.S.C. 1254(1).

(1)

2

STATUTORY PROVISIONS INVOLVED

Pertinent statutory provisions are reproduced in an

appendix to this petition. App., infra, 59a-84a.

STATEMENT

1. a. This case raises the same question currently

pending before the Court in Oklahoma v. EPA, 145 S. Ct.

411 (2024) (No. 23-1067), and PacifiCorp v. EPA, 145 S.

Ct. 411 (2024) (No. 23-1068). When a petitioner seeks

review of a “final action” taken by the EPA under the

Clean Air Act (CAA), 42 U.S.C. 7401 et seq., Section

7607(b)(1) of Title 42 provides for direct court of appeals

review of the petitioner’s challenge. To determine which

circuit has exclusive venue over the challenge, Section

7607(b)(1) separates EPA’s final actions into three categories.

First, challenges to certain specified actions or to “any

other nationally applicable regulations promulgated, or

final action taken,” must be filed “only in the United

States Court of Appeals for the District of Columbia.”

42 U.S.C. 7607(b)(1). Second, challenges to certain

specified actions, including an action “approving or

promulgating any implementation plan,” “or any other

final action * * * under [the CAA] (including any denial

or disapproval [under Title I of the CAA]) which is locally or regionally applicable may be filed only in the

United States Court of Appeals for the appropriate circuit.” Ibid. Third, “[n]otwithstanding” the sentence directing review of a locally or regionally applicable action to “the appropriate circuit,” challenges to such a locally or regionally applicable action “may be filed only

in the United States Court of Appeals for the District of

Columbia if such action is based on a determination of

nationwide scope or effect and if in taking such action

3

the Administrator finds and publishes that such action

is based on such a determination.” Ibid.

b. Under the CAA, EPA must set and periodically

revise national ambient air quality standards (NAAQS)

for particular pollutants, including ozone, to protect

public health and the environment. See 42 U.S.C. 7408,

7409. The CAA authorizes the States, in the first instance, to develop state implementation plans to achieve

and maintain those NAAQS, and to submit those plans

to EPA within three years after the promulgation of a

new or revised NAAQS. 42 U.S.C. 7410(a). To combat

cross-border pollution, the CAA requires each State’s

plan to prohibit in-state emissions that will “contribute

significantly to nonattainment” or “interfere with maintenance” of healthy air quality in any other State. 42

U.S.C. 7410(a)(2)(D)(i)(I). This statutory requirement

is known as the Good Neighbor Provision. See EPA v.

EME Homer City Generation L.P., 572 U.S. 489, 498

(2014).

When a State submits its plan to EPA, the agency

must assess the plan to determine whether it meets the

CAA’s requirements, including whether it prohibits any

significant contribution to nonattainment in other

States. If particular plans do not satisfy that requirement, EPA must disapprove those plans and promulgate federal plans to implement the requirements. 42

U.S.C. 7410(c)(1), (k)(2), and (3).

c. In 2015, EPA revised the NAAQS for ozone to set

a more stringent standard, triggering the requirements

for States to develop implementation plans. 80 Fed.

Reg. 65,292 (Oct. 26, 2015). EPA reviewed the state

plan submissions it received using a four-step framework it had developed for assessing Good Neighbor obligations for ozone. See, e.g., 76 Fed. Reg. 48,208,

4

48,248-48,249 (Aug. 8, 2011); EME Homer, 572 U.S. at

524 (rejecting challenges to this framework). After reviewing the submissions, EPA issued a final rule in

which it concluded that 21 States’ submissions—each of

which proposed no additional emissions reductions to

meet the more stringent ozone standard—must be disapproved because they failed to comply with the Good

Neighbor Provision. 88 Fed. Reg. 9336, 9338 (Feb. 13,

2023). EPA found that the 21 States had failed, on both

legal and technical grounds, to justify their conclusions

that their emissions do not significantly contribute to

nonattainment, or interfere with the maintenance, of

the relevant NAAQS in downwind States. Id. at 93549361. Respondent Kentucky was among those 21 States.

Id. at 9356.

Many of the 21 States offered substantially similar

reasons for asserting that they were not required to implement any additional emissions reductions. See, e.g.,

88 Fed. Reg. at 9354-9379 (summarizing States’ assertions and EPA’s responses). In disapproving the States’

submissions, EPA made uniform determinations to address the overlapping arguments the various States had

asserted in support of their plans. Ibid.

EPA then addressed judicial review of the action.

EPA explained that its rulemaking was “ ‘nationally applicable’ ” under Section 7607(b)(1) because the agency

was disapproving submissions “for 21 states located

across a wide geographic area” by “applying a uniform

legal interpretation and common, nationwide analytical

methods with respect to the [CAA’s] requirements * * *

concerning interstate transport of pollution.” 88 Fed.

Reg. at 9380.

“In the alternative,” EPA found that the “action is

based on a determination of ‘nationwide scope or ef-

5

fect.’ ” 88 Fed. Reg. at 9380. EPA explained in particular that, in disapproving the 21 state plans, the agency

was implementing “a common core of nationwide policy

judgments and technical analysis concerning the interstate transport of pollutants throughout the continental

U.S.” Ibid. EPA further explained that it had evaluated the plans “with an eye to ensuring national consistency and avoiding inconsistent or inequitable results

among upwind states * * * and between upwind and

downwind states.” Id. at 9381. EPA also observed that

“consolidated review of this action in the D.C. Circuit

will avoid piecemeal litigation in the regional circuits,

further judicial economy, and eliminate the risk of inconsistent results for different states.” Ibid.

2. Various States and industry groups challenged

EPA’s disapproval action with respect to 12 state plans.

Those challenges were filed in the D.C. Circuit and in

seven regional circuits. * Respondents (Kentucky and

the Kentucky Energy & Environment Cabinet) filed petitions for review in the Sixth Circuit. EPA moved to

transfer venue to the D.C. Circuit. App., infra, 12a. Respondents moved to stay the disapproval of Kentucky’s

plan pending review. Ibid. A motions panel granted the

stay and denied EPA’s motion to transfer. Id. at 12a-

See, e.g., West Virginia v. EPA, No. 23-1418 (4th Cir. Apr. 14,

2023); Texas v. EPA, No. 23-60069 (5th Cir. Feb. 14, 2023); Kentucky v. EPA, No. 23-3216 (6th Cir. Mar. 13, 2023); Arkansas v.

EPA, No. 23-1320 (8th Cir. Feb. 16, 2023); Missouri v. EPA, No. 231719 (8th Cir. Apr. 13, 2023); ALLETE, Inc. v. EPA, No. 23-1776

(8th Cir. Apr. 14, 2023); Nevada Cement Co. v. EPA, No. 23-682 (9th

Cir. Apr. 14, 2023); Utah v. EPA, No. 23-9509 (10th Cir. Feb. 13,

2023); Oklahoma v. EPA, No. 23-9514 (10th Cir. Mar. 2, 2023); Alabama v. EPA, No. 23-11173 (11th Cir. Apr. 13, 2023); Nevada v.

EPA, No. 23-1113 (D.C. Cir. Apr. 14, 2023).

*

6

13a. The parties then proceeded to merits briefing, and

EPA continued to contest venue. Id. at 13a.

The court of appeals rejected EPA’s renewed request to transfer venue, held that EPA’s disapproval of

Kentucky’s plan was arbitrary and capricious, and vacated the disapproval action as to Kentucky’s plan.

App., infra, 1a-47a.

With respect to venue, the court of appeals held that

the disapproval action is neither nationally applicable,

nor based on a determination of nationwide scope or effect. App., infra, 14a-34a. The court concluded that the

disapproval action is not nationally applicable because

it “formally applies to just 21 States—not the whole

country.” Id. at 18a. The court further viewed the “disapproval of each state plan * * * as a distinct ‘action’ ”

that is locally or regionally applicable. Id. at 22a. The

court likewise rejected EPA’s argument that the disapproval action is based on determinations of nationwide

scope or effect. The court reasoned that the term “determination” in Section 7607(b)(1) must be read to “refer[] to the agency’s ultimate decision—not each preliminary step on the road to that decision.” Id. at 26a.

The court therefore “ask[ed] whether the ultimate decision underlying the EPA’s ‘final action’ has a ‘nationwide scope or effect.’ ” Id. at 27a (quoting 42 U.S.C.

7607(b)(1)). The court concluded that “[n]othing about

the EPA’s decision to deny Kentucky’s plan has [nationwide] scope or effect.” Id. at 29a. The court also held

that EPA’s disapproval action was not “based on” two

of the determinations identified in the rule because

EPA had argued that it would have denied Kentucky’s

plan absent those determinations. Id. at 30a-31a.

On the merits, the court of appeals held that EPA’s

disapproval of Kentucky’s plan was arbitrary and capri-

7

cious because that disapproval relied on updated modeling and a lower threshold of ozone contribution than

EPA had previously identified in a memorandum, without adequately explaining either change. App., infra,

34a-42a. The court then concluded that those “defect[s]” warranted vacatur of the disapproval action with

respect to Kentucky’s plan. Id. at 46a; see id. at 44a47a.

Judge Murphy issued a concurring opinion to “highlight two issues that [the court] need not conclusively

decide”: whether EPA’s delay in acting on Kentucky’s

plan violated the Administrative Procedure Act (APA),

5 U.S.C. 551 et seq., 701 et seq., and whether remand

without vacatur is an available remedy under the APA.

App., infra, 48a; see id. at 48a-58a.

REASONS FOR GRANTING THE PETITION

The court of appeals below held that it was the

proper venue to hear respondents’ challenges to EPA’s

disapproval action, then vacated the disapproval action

with respect to Kentucky’s plan. App., infra, 14a-34a.

At this juncture, EPA is reassessing the basis for and

soundness of the disapproval action, and the concerns

raised by the decision below are part of that reassessment. Nonetheless, this Court granted certiorari in Oklahoma v. EPA, 145 S. Ct. 411 (2024) (No. 23-1067), and

PacifiCorp v. EPA, 145 S. Ct. 411 (2024) (No. 23-1068),

and consolidated the cases to consider whether the D.C.

Circuit is the proper venue under Section 7607(b)(1) to

hear challenges to the same disapproval action that is at

issue here. Because this case raises the same question,

the government is following its usual practice of filing a

petition for a writ of certiorari so that the Court could

hold this petition pending its decision in Oklahoma and

8

PacifiCorp, then dispose of the petition as appropriate

in light of that decision.

CONCLUSION

The petition for a writ of certiorari should be held

pending this Court’s decision in Oklahoma v. EPA, 145

S. Ct. 411 (2024) (No. 23-1067), and PacifiCorp v. EPA,

145 S. Ct. 411 (2024) (No. 23-1068), and then disposed of

as appropriate in light of that decision.

Respectfully submitted.

SARAH M. HARRIS

Acting Solicitor General

ADAM R.F. GUSTAFSON

Acting Assistant Attorney

General

MALCOLM L. STEWART

Deputy Solicitor General

AIMEE W. BROWN

Assistant to the Solicitor

General

JEFFREY HAMMONS

Attorney

MARCH 2025

APPENDIX

TABLE OF CONTENTS

Page

Appendix A — Court of appeals opinion (Dec. 6, 2024) ..... 1a

Appendix B — Statutory provisions:

42 U.S.C. 7410 ........................................ 59a

42 U.S.C. 7607(b)(1) .......................... 83a

(I)

APPENDIX A

UNITED STATES COURT OF APPEALS

FOR THE SIXTH CIRCUIT

Nos. 23-3216/3225

COMMONWEALTH OF KENTUCKY (23-3216);

KENTUCKY ENERGY AND ENVIRONMENT CABINET

(23-3225), PETITIONERS

v.

UNITED STATES ENVIRONMENTAL PROTECTION

AGENCY; MICHAEL S. REGAN, ADMINISTRATOR,

UNITED STATES ENVIRONMENTAL PROTECTION

AGENCY, RESPONDENTS

Argued: May 8, 2024

Decided and Filed: Dec. 6, 2024

On Petition for Review of a Final Agency Action of

the United States Environmental Protection Agency

Nos. EPA-HQ-OAR-2021-0663;

EPA-R04-OAR-2021-0841

OPINION

Before:

Judges.

BOGGS, KETHLEDGE, and MURPHY, Circuit

MURPHY, Circuit Judge. After the Environmental

Protection Agency (EPA) changed its air-quality standard for ozone under the Clean Air Act, the States needed

to amend their state plans to implement the new stand(1a)

2a

ard. To help the States with their plan revisions, the

EPA issued two guidance memoranda. It told the

States that they could use specific modeling to identify

their emissions that cross state lines. And it told them

that they presumptively need not worry about any interstate emissions that fall below a specific minimum

threshold. This guidance led Kentucky to propose a

plan that did not reduce its emissions further. But the

EPA sat on Kentucky’s proposed plan for some two

years—well past the Clean Air Act’s deadline for the

agency to act. It then belatedly disapproved the plan.

To Kentucky’s surprise, this disapproval rested on different modeling that came out after the EPA’s deadline

and on a lower threshold than the one the EPA told Kentucky it could use. Kentucky petitioned our court to

vacate the EPA’s disapproval. In response, the EPA

sought to transfer Kentucky’s challenge to the D.C. Circuit because the EPA had disapproved Kentucky’s plan

in a rule that also rejected 20 other state plans.

We deny the EPA’s motion to send this case to

the D.C. Circuit. Kentucky properly sued in this court

because the EPA’s disapproval was not a “nationally

applicable . . . final action” or one “based on a determination of nationwide scope or effect[.]” 42 U.S.C.

§ 7607(b)(1). The EPA’s view that a rule touching less

than half the country can qualify as “nationally applicable” conflicts with that phrase’s ordinary meaning and

would create much confusion over where to sue. At any

rate, the EPA cannot turn the quintessential “local” action (a state-plan decision) into a national one merely by

combining it with others. To fend off legal challenges

on the merits, the EPA’s final rule also clarified that its

decision to disapprove Kentucky’s plan rested on Ken-

3a

tucky’s unique facts. So its action was not “based on a

determination of nationwide scope or effect.”

We next hold that the EPA’s disapproval of Kentucky’s plan violated the Administrative Procedure Act

(APA). The EPA acted in an “arbitrary” way by telling

Kentucky one thing and then doing another. 5 U.S.C.

§ 706(2)(A). It recommended that Kentucky use certain modeling and a certain threshold. Yet it denied

Kentucky’s plan using different modeling and a different threshold. Ralph Waldo Emerson might have approved of this approach, since he once opined that “[a]

foolish consistency is the hobgoblin of little minds[.]”

Antonin Scalia, Assorted Canards of Contemporary Legal Analysis, 40 Case W. Res. L. Rev. 581, 587 (1989)

(quoting Ralph Waldo Emerson, Self-Reliance, in Essays and English Traits 66 (C.W. Eliot ed. 1909)). But

this “canard” has no place in legal reasoning because

“[c]onsistency is the very foundation of the rule of law.”

Id. at 588. Congress thus kept it out of our administrative law by passing the APA. Because the EPA has not

justified its inconsistencies here, we vacate its disapproval of Kentucky’s plan.

I

A

Like most laws, the Clean Air Act represents a compromise of competing interests. Cf. Luna Perez v.

Sturgis Pub. Schs., 598 U.S. 142, 150 (2023). Congress

sought to reduce pollution. 42 U.S.C. § 7401(a)(1)-(2).

But it also sought to respect state authority.

Id.

§ 7401(a)(3)-(4). The Act thus seeks to improve air

quality in a specific way: through “a model of cooperative federalism.” Sierra Club v. Korleski, 681 F.3d 342,

4a

343 (6th Cir. 2012) (quoting Ellis v. Gallatin Steel Co.,

390 F.3d 461, 467 (6th Cir. 2004)).

The cooperative process begins at the federal level.

The EPA must impose and periodically revise “national

ambient air quality standards” for each air pollutant.

42 U.S.C. § 7409(a)(1), (d). The EPA should set these

standards at a level that will “protect the public health.”

Id. § 7409(b)(1).

When the EPA adopts a revised air-quality standard

for a pollutant, the regulatory process shifts to the States.

Each State must develop an “implementation plan” (or

“[s]tate plan” for short) that will maintain and enforce

this standard within its borders.

Id. §§ 7407(a);

7410(a). A State must submit its plan to the EPA for

approval within three years of the revised air-quality

standard. Id. § 7410(a)(1). Its plan must satisfy many

statutory criteria. See id. § 7410(a)(2). The plan, for

example, must contain the emissions limits required to

meet the new standard. Id. § 7410(a)(2)(A).

Once the State submits its plan, the EPA must

approve or disapprove it within 18 months.

Id.

§ 7410(k)(1)-(3). The EPA must evaluate the plan only

against the statutory criteria. If the plan meets the

criteria, the EPA cannot reject it on the ground that the

State has chosen an unwise method to attain the airquality standard. See Ohio v. EPA, 603 U.S. 279, 284

(2024).

If the EPA disapproves a state plan, the agency must

issue a “[f]ederal implementation plan” that meets the

revised air-quality standard within the State.

42

U.S.C. § 7410(c)(1)(B). The agency may issue this federal plan “at any time within 2 years” from its disap-

5a

proval of the state plan. Id. § 7410(c)(1). But if the

State timely revises its plan to correct the original’s

deficiencies and the EPA approves that revised plan,

the EPA need not issue its own federal plan. Id.

§ 7410(c)(1)(B); see also EPA v. EME Homer City Generation, L.P., 572 U.S. 489, 507-10 (2014).

B

This case concerns a specific requirement that state

plans must meet: the “Good Neighbor Provision.”

EME Homer, 572 U.S. at 495. Pollutants emitted from

a source (say, a power plant) in one State often do not

stop at that State’s borders. Rather, the wind can

carry the pollutants “over hundreds of miles” to one or

more States. Id. at 496. This fact creates a classic

“negative externality”: an upwind State can shift some

of the cost of its activities (such as energy production) to

downwind States. See id. at 495. Without national

regulation, upwind States would have little incentive to

take these external costs into account. See id. So

downwind States might have to impose greater limits on

their own activities to achieve acceptable pollution levels. See id.

Congress adopted the Good Neighbor Provision to create the national coordination required for States to “internalize” these harms. See 42 U.S.C. § 7410(a)(2)(D).

This provision requires a state plan to include terms that

prohibit “any source or other type of emissions activity

within the State from emitting any air pollutant in

amounts which will . . . contribute significantly to

nonattainment in, or interfere with maintenance by, any

other State with respect to” an air-quality standard.

Id. § 7410(a)(2)(D)(i). How will States know whether

their emissions will have these interstate effects? To

6a

help them identify emissions that they may have to reduce, the EPA must classify all areas as “nonattainment” (if an area does not meet an air-quality standard)

or “attainment” (if it does). See id. § 7407(d); EME

Homer, 572 U.S. at 498.

The Supreme Court has addressed the Good Neighbor Provision once when evaluating the “Cross-State

Air Pollution Rule” (or “Transport Rule”) that the EPA

issued in 2011. EME Homer, 572 U.S. at 500. The

Transport Rule adopted a “two-step approach” for determining whether pollution sources in an upwind State

“contribute[d] significantly to nonattainment” in a

downwind State. Id. (citation omitted). First, the

EPA asked whether the upwind State had sources

linked to a downwind State’s “receptor[s]” (places where

the EPA measures air quality). Id. At this “screening” step, if an upwind State’s sources contributed only

a small part of the total pollutant at a downwind receptor (less than 1% of the air-quality standard for that pollutant), the Transport Rule decided that the State did

not “contribute[] significantly” to the downwind State’s

pollution problems. Id. at 501. Second, the Transport Rule relied on a cost-benefit analysis to control

emissions from States whose pollution contributions at

a receptor exceeded this 1% threshold. Id. at 500-01.

Ultimately, the Court relied on the now-overruled review scheme from Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984), to

hold that the Good Neighbor Provision’s text permitted

this approach. See EME Homer, 572 U.S. at 495-96; cf.

Loper Bright Enters. v. Raimondo, 144 S. Ct. 2244, 2273

(2024).

7a

C

This case also concerns a specific pollutant: ozone.

Although ozone in the atmosphere helps protect us

“from the sun’s radiation,” the pollutant at ground levels

can harm human health (for example, by inflaming our

lungs) and the earth’s vegetation (for example, by reducing crop yields). Ohio, 603 U.S. at 284; National Ambient Air Quality Standards for Ozone, 80 Fed. Reg.

65292, 65302-11, 65369-73 (Oct. 26, 2015). In October

2015, the EPA lowered the air-quality standard for

ozone from 75 to 70 parts per billion (or ppb). 80 Fed.

Reg. at 65330, 65365. This revision required the States

to submit revised implementation plans within three

years. See 42 U.S.C. § 7410(a). To help States develop plans that would meet the Good Neighbor Provision, the EPA released two memoranda in 2018.

March 2018 Memorandum. The EPA issued its

first guidance in March 2018. It told the States that it

planned to determine each State’s good-neighbor obligations using the same approach from the Transport

Rule (but the agency now divided this approach into four

steps). Mar. Mem., J.A. 76-77. At Step 1, the relevant federal or state regulator should “identify downwind” locations that will struggle to attain or maintain

the air-quality standard. Id. At Step 2, the regulator

should identify the upwind States whose pollution

sources “contribute enough to those downwind air quality problems to warrant further review[.]” Id. at 76.

At Step 3, the regulator should rely on cost considerations (among other things) to calculate the amount of

emissions reductions (if any) that an upwind State must

make so that it does not contribute to the “downwind air

quality problems[.]” Id. at 77. At Step 4, the regula-

8a

tor should identify “permanent and enforceable measures” to achieve these reductions. Id. The EPA told

States that their plans could follow this approach or “alternative frameworks” that comported with the Good

Neighbor Provision. Id.

This March 2018 Memorandum also included “modeling” data to predict ozone problems in downwind

States in 2023 and to identify the upwind contributors.

Id. The EPA suggested that the States could “consider

using this national modeling to develop” their plans.

Id. at 80. The modeling relied on data centered on pollution from 2011, so we will call it the “2011 modeling.”

Id. at 77-80. It identified two types of downwind “receptors”: those showing that a location would not attain the ozone standard in 2023 (“nonattainment receptors”) and those showing that a location would struggle

to maintain that standard in 2023 (“maintenance receptors”). Id. at 78.

August 2018 Memorandum. Five months later, the

EPA issued more “recommendations” for state plans.

Aug. Mem., J.A. 98.

These recommendations addressed “Step 2”—the “screening” step at which the

EPA eliminates the upwind States that contribute only

a small amount to downwind receptors. Id. at 99. As

with the Transport Rule, the EPA historically screened

out States that contributed less than 1% of an air-quality

standard. See EME Homer, 572 U.S. at 500 & n.3. If

the EPA applied this rule to the ozone standard of 70

ppb, it would set a .7 ppb “threshold” that a State’s contributions must exceed. Aug. Mem., J.A. 100. The

August 2018 Memorandum compared this 1% rule (.7

ppb) to a larger threshold: 1 ppb. Id. It found that

“the amount of upwind collective contribution” under

9a

both thresholds was “generally comparable[.]” Id. at

101. The EPA thus told States that they could use the

higher 1 ppb threshold. Id. According to the EPA, if

a State’s ozone contributions fell below 1 ppb at a receptor, the State could find that it did not contribute enough

pollutants to warrant further review at Steps 3 and 4.

Id. at 99. Yet the EPA also refused to guarantee approval of a state plan that followed this recommendation

because the recommendation might “not apply to the

facts and circumstances” of all States. Id. at 98.

D

Kentucky relied on these memoranda to draft its

plan. It used the 2011 modeling from the March 2018

Memorandum and the 1 ppb threshold from the August

2018 Memorandum. State Plan, J.A. 151-52. At Step

2, these choices showed that Kentucky exceeded the

screening threshold at only one maintenance receptor in

Harford County, Maryland. Id. at 152; Mar. Mem.,

J.A. 89. Kentucky contributed 1.52 ppb of ozone to this

location. State Plan, J.A. 152.

Turning to Step 3, Kentucky decided that it need not

impose further emissions reductions despite the link to

the Maryland receptor. Id. Kentucky gave several

reasons for this conclusion. To begin with, the Maryland receptor was a “maintenance” receptor, so the pollution there was less severe than the pollution at a “nonattainment” receptor. Id. Kentucky’s ozone-producing

emissions also would continue to decrease in future

years because of other regulations and because of the

expected “retirement of several” power plants. Id. at

163-66, 177-78. Kentucky also opined that “local” emissions in Maryland (such as local car traffic) contributed

far more than Kentucky emissions to ozone in the area.

10a

Id. at 173-77. The Commonwealth believed that the

EPA should compel “local sources” to reduce their emissions before requiring far-away sources to “overcontrol” their emissions. Id. at 173.

During Kentucky’s notice-and-comment process, the

EPA commented on its state plan. EPA Comments,

J.A. 124-28. Among other things, Kentucky’s plan used

an “intricate combination” of the 2011 modeling from

the March 2018 Memorandum and additional modeling

from a Kentucky contractor. Id. at 126. The EPA

recommended that Kentucky simply use the EPA’s 2011

modeling and its 1 ppb screening threshold as an “alternative, more straightforward approach[.]” Id. The

agency added that this approach would still connect

Kentucky only to the Maryland monitor. Id. The

EPA separately noted that Kentucky should specifically

identify the power-plant closures that EPA’s 2011 modeling failed to capture. Id.

After this feedback, Kentucky formally submitted its

plan in January 2019. State Plan, J.A. 129. When discussing the EPA’s comments, Kentucky “concur[red]

with EPA’s” simplified proposal. Id. at 454. Despite

the link to the Maryland monitor, Kentucky also continued to find that it need not reduce emissions. Id. at

178. In that respect, it identified the planned powerplant “shutdown” that the 2011 modeling had not considered. Id. at 454.

Under the Act, the EPA had until July 2020 to rule

on Kentucky’s plan. 42 U.S.C. § 7410(k)(1)(B), (2). That

date came and went without a ruling.

Nearly 20 months after the deadline, the EPA proposed a rule to disapprove Kentucky’s plan. Air Plan

11a

Disapproval, 87 Fed. Reg. 9498, 9498 (Feb. 22, 2022).

This rule included two surprises. As for the first, the

EPA used different modeling than the modeling in its

March 2018 Memorandum. See id. at 9500-01. The

new modeling centered on pollution in 2016, so we will

call it the “2016v2 modeling.” Id. As for the second,

the EPA rejected the 1 ppb threshold that its August

2018 Memorandum had recommended to screen out

small upwind contributions. Id. at 9502-03. The agency proposed returning to the lower threshold that the

Transport Rule had used: 1% of the air-quality standard (.7 ppb for the ozone standard). Id. These changes

affected Kentucky in different ways. On the one hand,

the new modeling no longer linked Kentucky to the Maryland receptor because that receptor was now adequately attaining the air-quality standard. Id. at 9507,

9509. On the other hand, the .7 ppb threshold linked

Kentucky to three nonattainment receptors in Connecticut and one maintenance receptor in Pennsylvania.

Id.

A year later, the EPA disagreed with Kentucky’s objections and issued a final rule disapproving its plan.

Air Plan Disapprovals, 88 Fed. Reg. 9336, 9356 (Feb. 13,

2023). This rule combined the EPA’s denial of Kentucky’s plan with its denial of 20 others. See id. at

9336-38 & n.8. The rule contained two fresh surprises.

The EPA again switched to new modeling: the “2016v3

modeling.” See id. at 9339, 9344. Although this modeling contained similar data as the 2016v2 modeling, it

included “models, methods, and source datasets that became available in calendar years 2020 through 2022[.]”

Id. at 9345. Further, the EPA now identified a third

type of “receptor”—what it called a “violating monitor”

—in addition to maintenance and nonattainment recep-

12a

tors. Id. at 9342. It chose this third group as a cautionary matter. Fresh information from 2021 and 2022

showed that certain locations were not attaining the

ozone standard even though the EPA’s modeling predicted that these areas would meet the standard. Id.

at 9349. At the same time, the EPA used these new

monitors only on a “confirmatory basis” and chose not

to rely on them as a sole ground to deny a state plan.

Id.

How did these fresh changes affect Kentucky? The

2016v3 modeling and 1% threshold continued to link

Kentucky to three Connecticut receptors. 2016v3 Modeling, J.A. 577. The EPA also linked Kentucky to four

new violating monitors in Connecticut, New York, Michigan, and Ohio. Id. at 578; see 88 Fed. Reg. at 9356.

Relying on these links at Step 2, the EPA found Kentucky’s proposal inadequate at Step 3. See 88 Fed.

Reg. at 9356.

E

The EPA’s disapproval of these 21 state plans triggered a flood of litigation. Many States sought review

of the EPA’s denials in their regional circuit courts.

Kentucky and its Energy and Environment Cabinet

(collectively, Kentucky) filed petitions for review in our

court, asking us to vacate the EPA’s disapproval of their

plan. The EPA responded by moving to transfer Kentucky’s case to the D.C. Circuit. Meanwhile, the Commonwealth moved to stay the EPA’s disapproval of its

plan pending our full review. In May 2023, a motions

panel granted a short administrative stay while it considered these motions. The same month, other circuit

courts also stayed the denials of other state plans. See

Ohio, 603 U.S. at 288-89.

13a

A few days after we granted our administrative stay,

the EPA imposed its own federal implementation plan

on Kentucky and 22 other States for the 2015 ozone

standard. Federal “Good Neighbor Plan” for the 2015

Ozone National Ambient Air Quality Standards, 88 Fed.

Reg. 36654, 36654 (June 5, 2023). States challenged

that plan in the D.C. Circuit. See Ohio, 603 U.S. at 290.

As litigation over the federal plan progressed, regional circuits continued to stay the EPA’s disapproval

of state plans. See id. In July 2023, we turned our administrative stay into a stay pending our full review.

Kentucky v. EPA, 2023 WL 11871967, at *5 (6th Cir.

July 25, 2023) (order). We also denied the EPA’s motion to transfer the suit to the D.C. Circuit. See id. at *13.

A short time later, the EPA stayed its federal plan

for the States that had obtained judicial stays. Federal

“Good Neighbor Plan” for the 2015 Ozone National Ambient Air Quality Standards, 88 Fed. Reg. 49295, 49295

(July 31, 2023). These stays grew to cover “12 of the

23” States subject to the federal plan. Ohio, 603 U.S.

at 289-90. Yet this plan’s emissions reductions rested

on the premise that all States would participate. See

id. at 287-88, 293-94. The Supreme Court thus stayed

the federal plan pending judicial review of that plan’s

validity. See id. at 300.

* * *

The Supreme Court’s decision completes the backdrop against which we must review Kentucky’s petitions

here. Those petitions raise three questions.

Did

Kentucky sue in the right court? If so, did the EPA

lawfully deny Kentucky’s plan? If not, what is the

14a

proper remedy? Our short answers: Yes, No, and

Vacatur. We will fill in the details to each answer in

turn.

II.

Did Kentucky Sue in the Right Court?

The EPA has renewed its request to transfer Kentucky’s petitions to the D.C. Circuit. Kentucky responds that we should reject this request based solely

on the motions panel’s earlier order denying the EPA’s

motion to transfer. See Kentucky, 2023 WL 11871967,

at *1-3. According to Kentucky, we must “defer[]” to

“the decisions of motions panels” and “cannot simply”

reject them. Wallace v. FedEx Corp., 764 F.3d 571, 583

(6th Cir. 2014). Yet we have never explained the

amount of deference due these decisions. Indeed, why

should we defer at all? We can (and sometimes do) depart from unpublished opinions. See Bell v. Johnson,

308 F.3d 594, 611 (6th Cir. 2002). And other circuits do

not defer to similar interlocutory rulings. See Tex.

Democratic Party v. Abbott, 978 F.3d 168, 176 (5th Cir.

2020); United States v. Lopez-Armenta, 400 F.3d 1173,

1175 (9th Cir. 2005); Am. Fed’n of Grain Millers, Loc.

24 v. Cargill Inc., 15 F.3d 726, 727 (7th Cir. 1994); 16AA

Charles A. Wright et al., Federal Practice and Procedure § 3973.3, at 256-60 (5th ed. 2023). Still, we may

save that question for another day. Even reviewing

the EPA’s motion de novo, we agree with the motions

panel that it lacks merit.

A.

Background Law

The Clean Air Act allows a party injured by an EPA

action to file a “petition for review” challenging the action in a circuit court of appeals. 42 U.S.C. § 7607(b)(1).

The Act’s (lengthy) judicial-review provision contains

15a

three basic parts. First, the provision gives the D.C.

Circuit the authority to review the EPA’s “nationally applicable” “regulations” or “final action”:

A petition for review of action of the Administrator in

promulgating any national primary or secondary ambient air quality standard, any emission standard or

requirement under section 7412 of this title, any

standard of performance or requirement under section 7411 of this title,[] any standard under section

7521 of this title (other than a standard required to

be prescribed under section 7521(b)(1) of this title),

any determination under section 7521(b)(5) of this title, any control or prohibition under section 7545 of

this title, any standard under section 7571 of this title, any rule issued under section 7413, 7419, or under

section 7420 of this title, or any other nationally applicable regulations promulgated, or final action

taken, by the Administrator under this chapter may

be filed only in the United States Court of Appeals

for the District of Columbia.

Id. Second, the provision gives the appropriate regional circuit court the authority to review the EPA’s

“locally or regionally applicable” actions:

A petition for review of the Administrator’s action in

approving or promulgating any implementation plan

under section 7410 of this title or section 7411(d) of

this title, any order under section 7411( j) of this title,

under section 7412 of this title, under section 7419 of

this title, or under section 7420 of this title, or his action under section 1857c-10(c)(2)(A), (B), or (C) of

this title (as in effect before August 7, 1977) or under

regulations thereunder, or revising regulations for

enhanced monitoring and compliance certification

16a

programs under section 7414(a)(3) of this title, or any

other final action of the Administrator under this

chapter (including any denial or disapproval by the

Administrator under subchapter I) which is locally or

regionally applicable may be filed only in the United

States Court of Appeals for the appropriate circuit.

Id. Third, the provision redirects even a locally or regionally applicable action to the D.C. Circuit if the action

is “based on a determination of nationwide scope or effect” and the EPA notes that the action has this scope

or effect:

Notwithstanding the preceding sentence a petition

for review of any action referred to in such sentence

may be filed only in the United States Court of Appeals for the District of Columbia if such action is

based on a determination of nationwide scope or effect and if in taking such action the Administrator

finds and publishes that such action is based on such

a determination.

Id.

Our court has yet to decide on the nature of this provision. Does it impose a (nonwaivable) jurisdictional

ban on the wrong circuit’s adjudication of a petition or

instead a (waivable) limit on the proper venue in which

to sue? See Wachovia Bank v. Schmidt, 546 U.S. 303,

315-16 (2006). Other courts have read § 7607(b) as

granting jurisdiction to all circuit courts, and they have

added that its circuit-specific rules identify only the

proper venue. See Texas v. EPA, 829 F.3d 405, 418

(5th Cir. 2016); Dalton Trucking, Inc. v. EPA, 808 F.3d

875, 879-80 (D.C. Cir. 2015); Clean Water Action Council of Ne. Wis., Inc. v. EPA, 765 F.3d 749, 751-52 (7th

17a

Cir. 2014). But the parties did not brief this distinction. And our holding that Kentucky sued in the right

court eliminates the need to decide it. Cf. Jaber v. Gonzales, 486 F.3d 223, 228 n.3 (6th Cir. 2007).

B.

Application

The EPA offers two reasons why this suit belongs in

the D.C. Circuit. It first argues that its disapproval of

the 21 state plans qualifies as a “nationally applicable

. . . final action.” And even if the disapproval of

Kentucky’s plan was “locally or regionally applicable,”

the EPA next argues that it was “based on a determination of nationwide scope or effect.” These claims have

created a circuit split. Apart from Kentucky, several

States have challenged the disapprovals of their plans in

regional circuits. And most circuit courts have held

that they (not the D.C. Circuit) represent the proper tribunal for the suits. See West Virginia v. EPA, 90 F.4th

323, 331 (4th Cir. 2024) (citing cases). The Tenth Circuit, by contrast, has sent challenges to the denial of Oklahoma’s plan to the D.C. Circuit. See Oklahoma ex

rel. Drummond v. EPA, 93 F.4th 1262, 1266-69 (10th

Cir. 2024), cert. granted, 2024 WL 4529798 (U.S. Oct. 21,

2024). We agree with the courts that have rejected the

EPA’s two arguments for D.C. Circuit review.

1. Did the EPA take a “nationally applicable” action when denying Kentucky’s plan?

The EPA argues that its rule disapproving the state

plans qualifies as a single “nationally applicable . . .

final action” rather than many “locally or regionally applicable” actions. 42 U.S.C. § 7607(b)(1). This claim

misreads the phrases “nationally applicable” and “final

action.”

18a

Nationally Applicable.

The EPA first misconstrues the phrase “nationally applicable” in § 7607(b)(1).

As with any case, we start with the “ordinary meaning”

of the words Congress used. Engine Mfrs. Ass’n v. S.

Coast Air Quality Mgmt. Dist., 541 U.S. 246, 252 (2004)

(quoting Park ‘N Fly, Inc. v. Dollar Park & Fly, Inc.,

469 U.S. 189, 194 (1985)); see Nat’l Ass’n of Mfrs. v.

Dep’t of Def., 583 U.S. 109, 127 (2018).

The key

words—“nationally applicable regulations promulgated,

or final action taken,” by the EPA—convey that the

challenged regulations or action must apply to the entire

country. 42 U.S.C. § 7607(b)(1). Because the phrasal

adjective “nationally applicable” modifies the nouns

“regulations” and “action,” the regulations or action

must “have reference to” (“applicable”) the “nation as a

whole” (“nationally”). 1 Oxford English Dictionary

575 (2d ed. 1989); 10 Oxford English Dictionary, supra,

at 235; Webster’s Third New Int’l Dictionary 105, 1505

(1976). We doubt that we need dictionaries for this

point. Would anyone say that Congress passed a “nationally applicable” law if the law formally applied to

only 40% of the country? No, the word “‘[n]ational’

contemplates an activity with a nationwide scope.”

Black’s Law Dictionary 923 (5th ed. 1979). And here,

all agree that the EPA’s rule formally applies to just 21

States—not the whole country.

Two canons of construction confirm this reading.

The sentence in § 7607(b)(1) that contains the “nationally applicable” clause triggers the “ejusdem generis”

canon. That canon applies to a catchall clause following a list of items. See Bissonnette v. LePage Bakeries

Park St., LLC, 601 U.S. 246, 252 (2024). It instructs

courts to interpret the catchall as falling within the same

class as the specific items that precede it. See id. So,

19a

for example, the phrase “seamen, railroad employees, or

any other class of workers” covers only transportation

workers—not all workers. 9 U.S.C. § 1; see Bissonnette, 601 U.S. at 252-53. The catchall clause here—

“any other nationally applicable regulations promulgated, or final action taken, by the” EPA—also follows

a list of specific actions that parties must challenge in

the D.C. Circuit. 42 U.S.C. § 7607(b)(1). And as far

as we can tell, those actions have nationwide applicability. See id. For example, challengers must sue in the

D.C. Circuit over “any national primary or secondary

ambient air quality standard[.]” Id. Likewise, they

must sue in the D.C. Circuit over the EPA’s “standards”

for stationary sources, hazardous pollutants, motor vehicles, fuels, and aircraft under 42 U.S.C. §§ 7411, 7412,

7521, 7545, and 7571. Id. § 7607(b)(1). And they must

sue in that court over the general “rules” that govern

enforcement (or similar) proceedings under §§ 7413,

7419, and 7420. Id. § 7607(b)(1). Given that the list in

§ 7607(b)(1) includes several national regulations, we

read the catchall to have a similar breadth. See Bissonnette, 601 U.S. at 252.

Next, courts presume that Congress means to adopt

“clear boundaries” in “jurisdictional statutes” to avoid

wasteful litigation over the proper forum.

Direct

Mktg. Ass’n v. Brohl, 575 U.S. 1, 11 (2015); see Miss. ex

rel. Hood v. AU Optronics Corp., 571 U.S. 161, 172-73

(2014); Hertz Corp. v. Friend, 559 U.S. 77, 94 (2010).

Even if § 7607(b)(1) is a mere venue provision, the Supreme Court would likely extend this “clear boundaries”

principle to § 7607(b)(1). See New York v. EPA, 133

F.3d 987, 990 (7th Cir. 1998). And our reading has “administrative simplicity” because it asks an objective

question: Does the action formally apply to the nation?

20a

Hertz, 559 U.S. at 94. The EPA’s view, by contrast,

would engender perpetual litigation over the actions

that are “nationally applicable.” The agency says its

rule here falls within that phrase because the rule covers

21 States in different parts of the country. Would this

logic reach an action that covered only California,

Maine, and Alabama because they fall in different parts

of the country? If not, how many more States are

needed? The EPA does not even try to answer these

questions.

Final Action.

The EPA also misconstrues the

phrase “final action” in § 7607(b)(1). It argues that its

disapprovals of the 21 state plans all qualify as a single

consolidated action rather than 21 separate actions. It

thus advocates for a “rulemaking approach” that treats

as a single “action” any regulatory decisions that the

EPA combines into a single rule in the Federal Register.

According to Kentucky, by contrast, the phrase “final

action” adopts a “statutory approach” that treats each

activity the Clean Air Act allows the EPA to take as a

distinct “action”—whether the EPA announces these

activities in a single rule or separate rules in the Federal

Register.

We side with Kentucky in this debate. This time,

though, the ordinary meaning of “action” does not help

all that much. That word means simply a “thing done”

or “something done.” Webster’s Third, supra, at 21;

Black’s, supra, at 26. So these (circular) definitions

leave the critical question unanswered: Did the EPA

do 21 “things” or a single “thing” in the rule?

That said, Kentucky’s approach better fits the “structure” of the judicial-review provision. Engine Mfrs.

Ass’n, 541 U.S. at 252. As a general matter, § 7607(b)(1)

21a

focuses on the statute (not the rulemaking) to distinguish the EPA actions that parties must challenge in the

D.C. Circuit from those they must challenge in regional

circuits. See Texas v. EPA, 2023 WL 7204840, at *4

(5th Cir. May 1, 2023) (per curiam). The provision ties

the proper tribunal to the activity taken “under this

chapter” (that is, under the Clean Air Act). 42 U.S.C.

§ 7607(b)(1). For example, § 7409(a)(1) requires the

EPA to issue a national air-quality standard “for each

air pollutant,” and § 7607(b)(1) sends a challenge to

“any” such “standard” to the D.C. Circuit. On the other

hand, § 7419(a)(1)(A) allows the EPA to issue a “primary

nonferrous smelter order” for a specific smelter, and

§ 7607(b)(1) sends a challenge to such an “order” to a

regional circuit. Nothing in § 7607(b)(1)’s text would

allow the EPA to obtain D.C. Circuit review of the smelter order simply by combining it with the air-quality

standard. Rather, the standard and the order represent distinct “actions” even if the EPA publishes them

in the same rule in the Federal Register.

Congress also knows how to refer to rules in the Federal Register when it wants to. Section 7607(b)(1) makes

the “notice” of an EPA action “in the Federal Register”

relevant to the 60-day limit for suing. Id. Congress

also required a “promulgated rule” to go through several procedures. Id. § 7607(d)(6)(A). Yet Congress

used “final action” (not “promulgated rule”) when deciding where parties must sue. Id. § 7607(b)(1), (d)(6)(A).

And courts normally presume Congress acts intentionally with such different word choices. See Burlington

N. & Santa Fe Ry. Co. v. White, 548 U.S. 53, 63 (2006);

Gen. Motors Corp. v. United States, 496 U.S. 530, 541

(1990).

22a

As a specific matter, § 7607(b)(1) clarifies that the

disapproval of each state plan qualifies as a distinct “action” that falls on the local side of this divide. The

Clean Air Act requires the EPA to “act” on each State’s

“submission” on a plan-by-plan basis within a specific

time. 42 U.S.C. § 7410(k)(2); see West Virginia, 90

F.4th at 330. The judicial-review provision then indicates that the EPA’s “action in approving . . . any

implementation plan” (in the singular) belongs in a regional circuit. 42 U.S.C. § 7607(b)(1). And while the

EPA denied Kentucky’s plan, this decision falls within

the catchall for “locally or regionally applicable” actions

(which includes a “denial or disapproval”). Id. As

then-Judge Kavanaugh explained, EPA action on a state

plan qualifies as the “prototypical” decision that belongs

in a regional circuit because of its local character. Am.

Rd. & Transp. Builders Ass’n v. EPA, 705 F.3d 453, 455

(D.C. Cir. 2013). So each state-plan denial in the

EPA’s rule qualifies as a distinct “action” under the

Clean Air Act. This reading makes this case easy:

the EPA’s disapproval of Kentucky’s plan is a locally applicable action.

The EPA’s contrary arguments do not convince us

otherwise. The agency offers no textual theory for its

view that the phrase “nationally applicable” can reach

an action applying to a hodgepodge of States that make

up less than half the nation. It instead jumps to precedent, suggesting that courts have treated EPA actions

as “nationally applicable” if they affect a large (unidentified) number of States. See S. Ill. Power Coop. v.

EPA, 863 F.3d 666, 671 (7th Cir. 2017); ATK Launch

Sys., Inc. v. EPA, 651 F.3d 1194, 1197 (10th Cir. 2011);

Texas v. EPA, 2011 WL 710598, at *3-4 (5th Cir. Feb.

24, 2011); W. Va. Chamber of Com. v. Browner, 1998 WL

23a

827315, at *2, *6-8 (4th Cir. Dec. 1, 1998) (per curiam).

But the Fifth Circuit has since clarified that the EPA

misread its precedent. See Calumet Shreveport Refin.,

L.L.C. v. EPA, 86 F.4th 1121, 1131 (5th Cir. 2023), cert.

granted, 2024 WL 4529794 (U.S. Oct. 21, 2024). True,

a regulation can be “nationally applicable” if its “legal

effect” applies to the whole country—even if its practical effect is felt only by a subset of States. Id. The

EPA could, for example, adopt a universal regulation

imposing requirements that practically apply to only

some States (say, because of their different geographies

or because the remaining States already satisfy the regulation). But the EPA seeks to go well beyond that

valid principle because it makes no claim that a rule disapproving 21 state plans formally applies everywhere.

As for the remaining circuits, we disagree with their

view that a regulation need not regulate the nation as a

whole to be “nationally applicable.” Take the Tenth

Circuit’s decision in ATK Launch Systems, 651 F.3d at

1197. It did not try to interpret the phrase “nationally

applicable.” Rather, it merely concluded that a regulation’s reach “from coast to coast and beyond” suffices

even if the regulation does not formally apply to the whole

nation. Id. But the court did not say why. And it left

many questions unanswered. How many States must a

rule cover? How spread out must the covered States

be? Nothing in the statute can answer these questions.

Next, the EPA suggests that we must consider the

“face of [its] rule”—not the rule’s “practical effect” as

applied to Kentucky—to decide whether it is “nationally

applicable.” Respondents’ Br. 32 (quoting ATK Launch

Sys., 651 F.3d at 1197). This argument conflates the

rule issued in the Federal Register (the EPA’s words)

24a

with the “final action” that the EPA takes (the statute’s

words). 42 U.S.C. § 7607(b)(1). Those phrases do not

mean the same thing. And the relevant final action

(the denial of Kentucky’s plan) applies only to Kentucky

on its face.

The EPA also argues that its disapprovals of the 21

plans represent a single “nationally applicable” action

because the disapprovals rested on a “uniform legal interpretation and common, nationwide analytical methods[.]” Respondents’ Br. 35 (quoting 88 Fed. Reg. at

9380-81). This theory conflicts with § 7607(b)(1)’s text

and structure. Starting with text, the phrase “nationally

applicable” modifies the action that the EPA takes—not

the reasons for it. And here, the action was a “prototypical” local decision. Am. Rd. & Transp. Builders

Ass’n, 705 F.3d at 455. Turning to structure, Congress

recognized that local actions might rest on national decisions. So it allowed D.C. Circuit review if the EPA

showed that a local action was “based on a determination

of nationwide scope or effect[.]” 42 U.S.C. § 7607(b)(1).

We would unravel this layered scheme if we looked to an

action’s justification at the start to decide whether the

action is national or local.

The EPA ends with policy. It suggests that Kentucky’s view inefficiently requires many courts to “concurrently” review actions that rest on the “same legal

interpretations, policy decisions, and analytical methodology,” which could generate “inconsistent” results. Respondents’ Br. 37. Yet we see competing “wisdom” in

“allowing difficult issues to mature through full consideration” by different courts. E.I. du Pont de Nemours

& Co. v. Train, 430 U.S. 112, 135 n.26 (1977). This expanded review increases the likelihood that the Su-

25a

preme Court will have all arguments before it when it

resolves the issue. See id. Regardless, the axiom that

“no legislation pursues its purposes at all costs” applies

just as much to procedural provisions as it does to substantive ones. CTS Corp. v. Waldburger, 573 U.S. 1, 12

(2014) (quoting Rodriguez v. United States, 480 U.S.

522, 525-26 (1987) (per curiam)). We thus must enforce

the judicial-review provision as written even if it conflicts with the EPA’s views of “sound policy.” Nat’l

Ass’n of Mfrs., 583 U.S. at 132 (quoting Florida Power

& Light Co. v. Lorion, 470 U.S. 729, 746 (1985)). And

the written text makes clear that the EPA took a locally

applicable action when disapproving Kentucky’s plan.

2. Is the denial of Kentucky’s plan “based on a determination of nationwide scope or effect”?

The EPA alternatively claims that, even if its disapproval of Kentucky’s plan was “locally or regionally applicable,” that disapproval was “based on a determination of nationwide scope or effect” under § 7607(b)(1).

88 Fed. Reg. at 9380. The EPA said as much in the final rule itself, so it met the separate requirement that it

“publish” this finding. Id.; 42 U.S.C. § 7607(b)(1).

The agency reasoned that all 21 disapprovals were

“based on a common core of nationwide policy judgments and technical analysis concerning the interstate

transport of pollutants throughout the continental U.S.”

88 Fed. Reg. at 9380. The EPA then listed three examples. First, the agency used the same four-step “framework” when disapproving all 21 plans. Id. Second,

the disapprovals rested on the 2016v3 modeling and a

uniform approach to identifying maintenance and nonattainment receptors. Id. at 9380-81. Third, the EPA

considered requests to use “alternative approaches or

26a

alternative sets of data” under the same standards. Id.

at 9381.

This interpretation misreads two other

phrases in § 7607(b)(1): “determination” and “based

on.”

Determination. The EPA argues that each analytical step in the chain of reasoning to its ultimate decision

for a “final action” qualifies as an independent “determination” that triggers review in the D.C. Circuit if at least

one step (considered in isolation) has a “nationwide scope

or effect.” 42 U.S.C. § 7607(b)(1). To give the obvious

example, the EPA reasons that every approval or disapproval of a state plan includes the choice to follow its

four-step “framework” for applying the Good Neighbor

Provision. 88 Fed. Reg. at 9380. Because this framework applies everywhere, the EPA says that every one

of its actions on a state plan will be “based on a determination of nationwide scope or effect” about the Good

Neighbor Provision’s meaning.

This broad reading of “determination” lacks merit.

We again start with the “ordinary meaning” of the text.

Engine Mfrs. Ass’n, 541 U.S. at 252. Admittedly, “determination” in the abstract could mean what the EPA

says because it can refer to any academic resolution of a

“question by argument or reasoning.” Webster’s Third,

supra, at 616. But the EPA’s reading does not fit the

context. When used to describe a ruling from an “administrative agency,” Black’s Law Dictionary, supra, at

405, “determination” has a more precise “legal meaning”

that refers to the agency’s ultimate decision—not each

preliminary step on the road to that decision. Smith v.

Spizzirri, 601 U.S. 472, 477 (2024); United States v. Hansen, 599 U.S. 762, 774 (2023). In other words, the word

“implies an ending or finality of a controversy or suit,”

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Black’s Law Dictionary, supra, at 405, and directs us to

look to the “authoritative decision” of the “matter at issue,” 4 Oxford English Dictionary, supra, at 548; Webster’s Third, supra, at 616; see also McQuillin v. Hartford Life & Accident Ins. Co., 36 F.4th 416, 420 (2d Cir.

2022). This understanding shows that courts should

ask whether the ultimate decision underlying the

EPA’s “final action” has a “nationwide scope or effect.”

42 U.S.C. § 7607(b)(1); see West Virginia, 90 F.4th at

328-29.

The EPA’s “unbounded interpretation,” by contrast,

would upset Congress’s “careful delineation” of the actions that parties should challenge in the D.C. Circuit

and those that they should challenge in regional circuits.

Fischer v. United States, 603 U.S. 480, 493 (2024). If

“determination” covered each discrete choice the EPA

makes en route to a final decision, every “final action”

rests on a nationwide “determination.” After all, the

EPA always must ground its actions in a “national rule

or standard” in the Clean Air Act or its regulations.

West Virginia, 90 F.4th at 328. The agency cannot

haphazardly regulate parties by adopting one view of

the law for some States and the opposite view for others.

The EPA’s reading thus would allow it to send every action to the D.C. Circuit despite Congress’s presumptive

choice to keep local actions local.

To be sure, the EPA’s reading would not make Congress’s choice entirely “superfluous.” Fischer, 603 U.S.

at 493. Even if all local actions rest on nationwide determinations (as the EPA implies), the agency still must

“publish[]” a finding to that effect. 42 U.S.C. § 7607(b)(1).

If it opts not to, parties could sue in regional circuits.

The EPA thus asks us to give it total discretion to decide

28a

where parties should sue. But this fact confirms its error because § 7607(b)(1) does not grant it this discretion.

Recall that the relevant sentence sends a local action to

the D.C. Circuit only if both the action “is based on a

determination of nationwide scope or effect and” the

EPA “publishes that such action is based on such a determination.” Id. (emphasis added). So the action

must rest on a nationwide determination (the first requirement) independent of the EPA’s published views

(the second requirement). Congress would not have

written this sentence in the conjunctive if it meant to

give the EPA complete discretion.

It would have

simply said that a local action belongs in the D.C. Circuit

if the EPA finds that it rests on a national determination. All told, then, “determination” refers to the

EPA’s “authoritative” answer to the question it resolves

when taking an action. 4 Oxford English Dictionary,

supra, at 548.

This definition proves the EPA’s error here. The

agency suggests that its preliminary choices (such as its

use of the four-step framework for the Good Neighbor

Provision) were independent “determination[s]” under

§ 7607(b)(1). But those choices did not “end[]” the

“controversy”: whether the EPA should approve Kentucky’s plan. 4 Oxford English Dictionary, supra, at

548.

Instead, the “determination” underlying the

EPA’s disapproval was its ultimate decision that Kentucky did not satisfy the Good Neighbor Provision. See

88 Fed. Reg. at 9356.

We thus must ask whether this decision about Kentucky’s plan had a “nationwide scope or effect” under

§ 7607(b)(1). It did not. Like “nationally applicable,”

the word “nationwide” shows that a determination’s

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“scope or effect” must exist “throughout [the] entire nation.” Webster’s Third, supra, at 1505; West Virginia,

90 F.4th at 328. And the phrase “scope or effect”

shows that this provision reaches EPA decisions that apply to the entire country as a legal matter (de jure) or as

a practical one (de facto). That is, a determination

might have a nationwide “scope” if its formal “area” of

operation covers the country. 14 Oxford English Dictionary, supra, at 672; see Webster’s Third, supra, at

2035. And it might have a nationwide “effect” if its “operative influence” is felt everywhere. 5 Oxford English Dictionary, supra, at 79; see Webster’s Third, supra, at 724.

Nothing about the EPA’s decision to deny Kentucky’s plan has this scope or effect. To the contrary,

the agency decided that Kentucky’s plan did not satisfy

the Good Neighbor Provision due to “circumstances

. . . unique” to that plan. West Virginia, 90 F.4th at

328. To start, the EPA found that Kentucky wrongly

suggested at Step 2 of its framework that the Commonwealth’s emissions sources were linked only to a Maryland receptor. See 87 Fed. Reg. at 9509. The EPA

decided instead that Kentucky sources were linked to

three Connecticut receptors. 88 Fed. Reg. at 9356;

2016v3 Modeling, J.A. 577. Next, the EPA disagreed

with Kentucky’s “particular arguments” for using the

higher 1 ppb threshold (rather than the lower 1%

threshold) to weed out the receptors with which it had

an insufficient connection. 88 Fed. Reg. at 9373 (emphasis added). Because Kentucky’s connection to the

Connecticut receptors fell in between these thresholds,

the EPA proceeded to Step 3. See id. at 9356. It

lastly found that Kentucky did not adequately show at

that step why it need not reduce any emissions to help

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the Connecticut receptors attain the ozone standard.

Id. This logic applied only to Kentucky and had, at most,

regional effects. So the EPA does not even try to argue that its final “determination” had any sort of nationwide scope or effect.

Based On. Apart from the EPA’s overbroad reading of “determination,” it disregards that the final action

must be “based on” the identified determinations. 42

U.S.C. § 7607(b)(1). In ordinary English, one would

say that a person’s action (say, taking an umbrella on a

trip) is “based on” a factor (say, the high chance of rain)

if the person has “ground[ed]” the action in that factor.

McGraw-Hill’s Dictionary of American Idioms and

Phrasal Verbs 34 (2005). When a statute uses a phrase

like “based on” to connect one thing to another in this

way, the Supreme Court has relied on a “traditional

background principle[]”—but-for causation—to eliminate factors that an action could not have been based on.

Burrage v. United States, 571 U.S. 204, 213-14 (2014);

Safeco Ins. Co. of Am. v. Burr, 551 U.S. 47, 63 (2007); see

also Univ. of Tex. Sw. Med. Ctr. v. Nassar, 570 U.S. 338,

350 (2013). Under this test, the person’s decision to

take an umbrella could not have been based on the

chance of rain unless the person would have left the umbrella at home “but for” this chance. Burrage, 571 U.S.

at 212. That is, the chance of rain must have mattered

to that decision. See id. at 211-12. Here, then, if the

EPA would have taken the same “action” without the alleged “determination,” nobody would say the action was

“based on” the determination.

This reading of “based on” independently dooms the

EPA’s reliance on two of the alleged “determinations”

identified in the final rule. The agency suggested that

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its denial of Kentucky’s plan rested on its decision to

rely on the 2016v3 modeling and its use of “uniform” criteria to evaluate each State’s request to use a 1 ppb

threshold rather than a threshold of 1% of the ozone

standard (.7 ppb). 88 Fed. Reg. at 9380. In this court,

however, the EPA claims that it would have denied Kentucky’s plan even if it had allowed Kentucky to use the

2011 modeling and 1 ppb threshold. Respondents’ Br.

56-57. Under that older modeling and higher threshold, Kentucky sources were still linked to a Maryland

receptor. State Plan, J.A. 152. And the EPA argues

that Kentucky did not adequately explain why it need

not cut emissions to allow this receptor to meet the ozone

standard. Respondents’ Br. 57-68. Yet if the EPA

would have denied Kentucky’s plan anyway, that denial

could not have been “based on” the agency’s use of the

later modeling and lower threshold. So these decisions

cannot allow the EPA to take this case to the D.C. Circuit.

The EPA’s responses again lack merit. It makes

two textual arguments to support its reading of “determination.” The agency first points out that the statute

uses “a” to modify “determination” (“based on a determination of nationwide scope or effect”). This indefinite article allegedly implies that an action can rest on

multiple determinations and that only one need have a

“nationwide scope or effect.” But the EPA places too

much weight on this article. Because “determination”

is a “countable noun[],” basic grammar rules required

Congress to use the article (nobody would say “based on

determination”). Niz-Chavez v. Garland, 593 U.S. 155,

162-63 (2021). And the use of “a” says nothing about

whether “determination” should reach each of the EPA’s

nonfinal interpretive choices or just its final decision.

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If anything, the decision to use a singular noun could

just as well convey that the final action must rest on a

“single” decision—not on many separate decisions. Id.

at 163.

The EPA also suggests that our reading of “determination” suffers from the same problem as its reading:

we allegedly strike this clause out of the statute because

the final “applying-the-law-to-the-facts” decision that

underlies any local action will never have the required

nationwide scope or effect. Yet caselaw existing before

Congress amended the key language in § 7607(b)(1) offers examples of state-plan “determinations” that might

have a “nationwide scope or effect.” Take Dayton

Power & Light Co. v. EPA, 520 F.2d 703 (6th Cir. 1975).

There, the EPA followed a “unitary rule-making procedure” to adopt regulations that had “the effect of amending every state’s air quality implementation plan in precisely the same way.” Id. at 705. Interpreting an earlier version of the statute, we held that the challenges to

these uniform state-plan amendments belonged in the

D.C. Circuit. Id. at 706-09. Thus, when the “automatic application of standard, nation-wide guidelines to

all plans simultaneously preordains wholesale” actions,

the EPA “determination” may well have a nationwide

scope or effect. Nat. Res. Def. Council, Inc. v. EPA,

465 F.2d 492, 494 (1st Cir. 1972) (per curiam). But the

EPA makes no such claim here.

Moving away from the text, the EPA argues that the

legislative history supports its view. When discussing

this judicial-review provision, a House Report agreed

“with the comments” in a statement accompanying recommended amendments that had been proposed by the

Administrative Conference of the United States. H.R.

33a

Rep. 95-294, at 324 (1977) (discussing Admin. Conf. of

the U.S., Recommendations on Judicial Review Under

the Clean Air Act, 41 Fed. Reg. 56767, 56769 (Dec. 30,

1976) (Statement of G. William Frick)). These comments

suggested that Congress should send “‘national’ [stateplan] issues” to the D.C. Circuit. 41 Fed. Reg. at 56769.

Yet this meaningless statement says nothing about the

key question: Which state-plan issues are “national”?

In fact, this legislative history may well cut the other

way. The statement relied on by the EPA cites decisions like Dayton Power & Light as examples of the uniform regulations that belong in the D.C. Circuit. See

41 Fed. Reg. at 56769 & n.3. And again, the EPA’s denial of Kentucky’s plan here looks nothing like the regulations in that case. In all events, we cannot use (at

best) ambiguous legislative history to muddy the unambiguous meaning of statutory phrases like “nationwide.”

See Food Mktg. Inst. v. Argus Leader Media, 588 U.S.

427, 437 (2019). Nothing about the disapproval of Kentucky’s plan has a national sweep.

The EPA also claims that we should use a “deferential standard” to review whether an agency action rests

on “a determination of nationwide scope or effect” under

§ 7607(b)(1). Respondents’ Br. 46. But the Supreme

Court has recently told courts that we should no longer

defer to an agency’s answers to legal questions. See

Loper Bright, 144 S. Ct. at 2273. And the EPA resolves

a pure question of law when it interprets the key terms

in § 7607(b)(1) (such as “nationally applicable” or “determination”). After Loper Bright, we must review

(and correct) the agency’s mistaken interpretation of

those terms without giving it deference.

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The EPA lastly makes a big-picture point. It says

that any decision about the Good Neighbor Provision

will always involve nationwide issues because this part

of the Clean Air Act concerns pollution that crosses state

lines. This argument all but confirms its error: it reads

words like “nationally applicable” and “nationwide” to

mean “regionally applicable” or “regional.” The Good

Neighbor Provision regulates pollution as long as it is

emitted from one “State” and travels to “any other

State[.]” 42 U.S.C. § 7410(a)(2)(D)(i). It thus would

cover pollution emitted from St. Louis that landed just

across the Mississippi River in East St. Louis. Yet nobody would say that the EPA made a “nationwide” determination when it decided whether Missouri adequately accounted for this Illinois pollution problem.

In the end, the EPA’s fact-specific denial of Kentucky’s

plan belongs in our court, not the D.C. Circuit.

III.

Did the EPA Lawfully Disapprove

Kentucky’s Plan?

Because Kentucky sued in the right tribunal, we proceed to the merits. Our court has evaluated the EPA’s

disapprovals of state plans using the APA’s general

standards. See Navistar Int’l Transp. Corp. v. EPA,

941 F.2d 1339, 1341 (6th Cir. 1991); Dressman v. Costle,

759 F.2d 548, 555 (6th Cir. 1985); cf. 42 U.S.C. § 7607(d)(1),

(9). Under those standards, a court must “hold unlawful and set aside agency action” that the court finds “arbitrary, capricious, an abuse of discretion, or otherwise

not in accordance with law.” 5 U.S.C. § 706(2)(A).

We need not proceed past § 706(2)(A)’s ban on “arbitrary” and “capricious” actions to resolve this case.

That ban requires agencies to make reasonable decisions in a reasonable way. See FCC v. Prometheus Ra-

35a

dio Project, 592 U.S. 414, 423 (2021); Dep’t of Homeland

Sec. v. Regents of the Univ. of Cal., 591 U.S. 1, 16 (2020).

Under this deferential “reasonableness” test, a court

cannot set aside an action simply because it would have

made a different choice. See Prometheus Radio Project, 592 U.S. at 423. But the court must ensure that

the agency considered each “important aspect of the

problem” and issued a decision rooted in the law and

facts. Motor Vehicle Mfrs. Ass’n of U.S., Inc. v. State

Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983).

When an agency departs from its prior position, the

change creates unique “aspect[s] of the problem” that it

must confront. Id.; Encino Motorcars, LLC v. Navarro, 579 U.S. 211, 221-22 (2016). To start, the agency

must “display awareness” that it has, in fact, jettisoned

its past views. FCC v. Fox Television Stations, Inc.,

556 U.S. 502, 515 (2009). This requirement does not

compel the agency to meet a “heightened” reasonableness test as compared to when it adopts a policy from

scratch. Id. at 514. Still, the agency must acknowledge the change and explain why it sees things differently. See Encino Motorcars, 579 U.S. at 221. So while

the agency can make a “U-turn,” it cannot make an unexplained one. Casey v. Berryhill, 853 F.3d 322, 329

(7th Cir. 2017). Courts thus have found agency action

arbitrary and capricious when it rested on an “[u]nexplained inconsistency” with past practice. Encino Motorcars, 579 U.S. at 222 (citation omitted).

Next, the agency must address how a change will affect those who have relied on its prior position. See Fox,

556 U.S. at 515; Smiley v. Citibank (S.D.), N.A., 517 U.S.

735, 742 (1996). The agency should identify these reliance interests and weigh them against the “policy” rea-

36a

sons supporting the change. Regents of the Univ. of

Cal., 591 U.S. at 33. The Supreme Court has held, for

example, that an agency arbitrarily adopted a more

employee-friendly view of the wage-and-hour laws when

the agency ignored that employers had structured their

payment arrangements based on the agency’s past interpretation. See Encino Motorcars, 579 U.S. at 22224. And this mandate to address reliance interests applies just as much to an agency’s departure from informal guidance as it does to its departure from formal regulations. See Perez v. Mortg. Bankers Ass’n, 575 U.S.

92, 105-06 (2015).

The EPA failed to live up to these standards here.

The agency’s denial of Kentucky’s plan departed from

prior guidance in three respects. For one, the EPA’s

March 2018 Memorandum told the States (including

Kentucky) that they “may consider using” the 2011 modeling to develop their plans for the first two steps of the

EPA’s four-step approach to the Good Neighbor Provision. Mar. Mem., J.A. 80. For another, the EPA’s

August 2018 Memorandum told the States that “it may

be reasonable and appropriate for [them] to use a 1 ppb

contribution threshold” when identifying the links to

downwind receptors that require more scrutiny at the

agency’s later steps. Aug. Mem., J.A. 101. The EPA

issued this memo to “provide[] recommendations” to

States but added that this presumption of a 1 ppb

threshold may not fit “the facts” of a particular State.

Id. at 98. For a third, the EPA saw nothing about Kentucky’s unique “facts” that warranted a departure from

these recommendations. Id. To the contrary, the

EPA told Kentucky during the Commonwealth’s noticeand-comment process that it could “rely entirely” on the

2011 modeling and 1 ppb threshold as a “more straight-

37a

forward approach” at Step 2.

126.

EPA Comments, J.A.

The EPA threw out all this guidance when it disapproved Kentucky’s plan. The EPA relied on the 2016v3

modeling—not the 2011 modeling that it had recommended—to identify Kentucky’s links to downwind receptors. 88 Fed. Reg. at 9356. Even worse, this new

modeling showed that Kentucky’s highest contribution

to a maintenance or nonattainment receptor was only

“0.84 ppb,” which is below the 1 ppb threshold that the

EPA had recommended. Id. Yet the EPA denied

Kentucky’s plan by using a lower threshold: 1% of the

ozone standard (.7 ppb). See id.; see also id. at 9342.

The EPA acted arbitrarily because it did not adequately

explain either change.

Threshold Change. The EPA did not even “display

awareness” that its switch from a 1 ppb threshold to a .7

ppb threshold changed anything. Fox, 556 U.S. at 515.

The EPA’s final rule reasoned that its August 2018

Memorandum had cautioned that the recommended 1

ppb threshold might not fit the “facts and circumstances” of all States. 88 Fed. Reg. at 9372. It then

invoked this disclaimer to find that no State “made a sufficient showing” to use this threshold. Id. at 9373.

Yet the EPA’s logic flipped the key presumption. The

August 2018 Memorandum treated the 1 ppb threshold

as presumptively acceptable unless a State’s unique

facts made the threshold improper, but the final rule

treated the 1 ppb threshold as presumptively unacceptable unless that threshold fit a State’s facts. The

August 2018 Memorandum had presumptively allowed

States to use the 1 ppb threshold because it was “generally comparable” to a .7 ppb threshold in capturing up-

38a

wind contributors to downwind receptors. Aug. Mem.,

J.A. 101. When departing from this presumption, did

the EPA disagree that the thresholds were generally

comparable in this way? Did it change for another reason? The EPA did not even acknowledge the change,

let alone explain it. See Encino Motorcars, 579 U.S. at

221-22.

The EPA instead accused States like Kentucky of

“misunderstanding” the August 2018 Memorandum by

accepting at face value what it said. 88 Fed. Reg. at

9373. “That’s a bit rich.” Mingo Logan Coal Co. v.

EPA, 829 F.3d 710, 740 (D.C. Cir. 2016) (Kavanaugh, J.,

dissenting). It is especially rich in Kentucky’s case.

The EPA specifically told Kentucky that it could “rely”

on the 1 ppb threshold. EPA Comments, J.A. 126. So

by “disagree[ing] with Kentucky’s arguments for” that

threshold, the agency was disagreeing with itself. 88

Fed. Reg. at 9356.

Modeling Change. When deciding to switch to the

2016v3 modeling, by comparison, the EPA ignored the

“serious reliance interests” that arose from its earlier

assurance that States could use the 2011 modeling.

Fox, 556 U.S. at 515. To justify the newer modeling,

the EPA reasoned that it should be able to use “the best

information available to it at the time it” decides on a

plan’s validity. 88 Fed. Reg. at 9366. This logic ignored

an “important aspect of the problem”: Kentucky’s reliance on the March 2018 Memorandum. State Farm,

463 U.S. at 43. Indeed, the EPA’s briefing cites nothing in the rule that even acknowledged this reliance interest.

If the EPA had “considered” Kentucky’s reliance, it

might have chosen an alternative to its flat disapproval.

39a

Regents of the Univ. of Cal., 591 U.S. at 32. As Kentucky suggested, the EPA could have announced in advance that it would use newer data and given States the

option to update their plans. Ky. Comments, J.A. 51314. In response to comments like this one, the EPA argued that the Clean Air Act did not require it to give

States “specific metrics” to help them comply with the

Good Neighbor Provision. 88 Fed. Reg. at 9363 (quoting EME Homer, 572 U.S. at 510). Yet this generic response ignores the key question: May the EPA affirmatively give the States one set of “metrics” to draft their

plans and then use another set of metrics to grade them?

The EPA’s response thus confirms its utter disregard of

Kentucky’s reliance interest.

The EPA’s defenses of these changes lack merit.

First, the EPA rests on the disclaimer in the August

2018 Memorandum that its recommended 1 ppb threshold might not fit a State’s facts. But this disclaimer

does the EPA no good as applied to Kentucky. Again,

the memorandum proposed the 1 ppb threshold because

it captured a “generally comparable” amount of upwind

contributions to downwind receptors as would a .7 ppb

threshold. Aug. Mem., J.A. 101. So if the 1 ppb

threshold was not “comparable” to a .7 ppb threshold for

a particular State and receptor, this approach might

give way. But the EPA has made no receptor-specific

argument for Kentucky. Indeed, the memorandum itself listed all receptors to which Kentucky contributed

over .7 ppb when finding the two thresholds comparable.

Compare Aug. Mem., J.A. 102-03, with State Plan, J.A.

152. The EPA instead argues that Kentucky did not

provide an adequate “technical justification” for the

higher threshold. Respondents’ Br. 70. Yet the EPA

does not explain what “technical” justification Kentucky

40a

needed beyond the one in the EPA’s own prior memorandum.

Second, the EPA suggests that its comments about

Kentucky’s draft plan did not promise that Kentucky

could rely on the 2011 modeling or 1 ppb threshold

“without conducting further analysis and offering technical justification.” Respondents’ Br. 70. That is

false. When discussing the modeling data in Kentucky’s plan, the EPA stated: “An alternative, more

straightforward approach would be to rely entirely upon

the EPA’s [2011 modeling] and apply the 1 ppb screening threshold” from the August 2018 Memorandum.

EPA Comments, J.A. 126 (emphasis added). The EPA

did not then warn that it might still reject the state plan

despite this recommendation.

Third, the EPA says that Kentucky could not have

relied on the two memoranda because the EPA did not

have a “longstanding policy” of using only modeling data

in existence when a State submitted a plan or a 1 ppb

threshold. Respondents’ Br. 72, 88 (quoting Breeze

Smoke, LLC v. FDA, 18 F.4th 499, 507 (6th Cir. 2021)

(order)).

This argument misunderstands the law.

While “longstanding policies” suffice to create reliance

interests, Encino Motorcars, 579 U.S. at 222, they are

not necessary to do so. Such interests can arise in

other ways—such as when an agency tells a party that

it can do something during the rulemaking process.

See EPA Comments, J.A. 126. A contrary holding

would allow agencies to “pull a surprise switcheroo” by

issuing a final action that flatly contradicts prior guidance, as long as the action does not depart from some

traditional practice. Env’t Integrity Project v. EPA,

425 F.3d 992, 996 (D.C. Cir. 2005).

41a

The EPA’s support for this alleged “longstanding

policy” requirement—our decision in Breeze Smoke—is

not to the contrary. There, we recognized that an

agency’s earlier guidance was not “longstanding,” so a

party could not rely on caselaw refusing to defer to

agency actions that inexplicably departed from traditional practice. Breeze Smoke, 18 F.4th at 507. But

we did not uphold the agency action in Breeze Smoke on

this basis alone. Rather, we also rejected the regulated party’s other claim that the agency had told the

party one thing during the regulatory process and then

done something different when taking the final action.

See id. at 506-07. We reasoned that the final action

comported with the earlier guidance, so the party could

not have relied on anything in that guidance to believe

that the agency would act differently. See id. Here,

by contrast, a clear conflict exists. The EPA told Kentucky that it could use the 2011 modeling and 1 ppb

threshold and then denied Kentucky’s plan in large part

because Kentucky had done what the EPA told it to do.

Because the EPA did not adequately consider Kentucky’s “reliance interests” when changing course in

these ways, it acted arbitrarily. Fox, 556 U.S. at 515.

Fourth, the EPA argues that Kentucky did not prove

its reliance because it did not incur “substantial” monetary “costs” using the 2011 modeling. Respondents’ Br.

93. But Kentucky wasted the costs it incurred drafting

its plan because the EPA evaluated that plan using a different yardstick from the one the agency promised. Regardless, as a sovereign entity, Kentucky possesses the

“primary responsibility” to regulate pollution emitted

from its borders and the discretion to decide how best to

meet air-quality standards. 42 U.S.C. § 7401(a)(3); Ohio,

603 U.S. at 284. Kentucky placed this important regu-

42a

latory interest on the line when it chose to rely on the

EPA’s 2011 modeling. And it lost that interest when

the EPA used newer data to disapprove its plan and to

impose a federal plan that took the Commonwealth’s

regulatory discretion. See 42 U.S.C. § 7410(c). Given

the Clean Air Act’s “cooperative federalism” design, Sierra Club, 681 F.3d at 343 (quoting Ellis, 390 F.3d at

467), this type of sovereign reliance interest warrants

protection under the APA, see Ohio, 603 U.S. at 291.

* * *

Even if the EPA acted arbitrarily and capriciously in

the ways that we have explained, the agency claims that

we should find its mistakes harmless. The EPA opines

that it would have denied Kentucky’s plan even if it had

judged the plan using Kentucky’s 2011 modeling and 1

ppb threshold. Under those datapoints, Kentucky still

contributed to a Maryland monitor at Step 2. State

Plan, J.A. 152. And the EPA now argues that Kentucky gave inadequate reasons at Step 3 as to why it

need not cut omissions to keep this monitor in attainment. Respondents’ Br. 57-68. The problem? Under basic principles of administrative law, agencies may

invoke in court only the grounds that they relied on at

the time they took the challenged action. See Regents

of the Univ. of Cal., 591 U.S. at 20. If those relied-upon

reasons cannot sustain an agency action, neither a court

nor an agency may salvage the action by invoking “better” reasons for it in litigation. See id. at 22-23; see also

Calcutt v. FDIC, 598 U.S. 623, 628-29 (2023) (per curiam).

This principle renders the EPA’s harmless-error arguments premature. The EPA did not rely on its current Step 3 claims to deny Kentucky’s state plan. To

43a

be sure, its rule did state that Kentucky “did not conduct

an adequate Step 3 analysis.” 88 Fed. Reg. at 9356.

But the EPA’s four-part approach raises distinct “steps”

for a reason. The validity of a State’s decision on what

emissions to cut at Step 3 depends on the State’s links

at Step 2. And the EPA’s rule used the 2016v3 modeling at Step 2 to link Kentucky to Connecticut receptors.

See id.; 2016v3 Modeling, J.A. 577. At Step 3, then, the

rule analyzed these receptors. The agency noted, for

example, that Kentucky was still linked to them even after the agency considered Kentucky’s planned powerplant shutdowns. See 88 Fed. Reg. at 9356. The rule,

by contrast, did not suggest that Kentucky’s Step 3 analysis would fall short for the Maryland receptor linked

to Kentucky under the 2011 modeling. Because the

EPA abandoned this modeling, it did not even ask that

question.

Nor do we find it a forgone conclusion that the EPA

would deny Kentucky’s plan on remand. See Calcutt,

598 U.S. at 629-30. Suppose the EPA kept its 2016v3

modeling but retained the higher 1 ppb threshold. In

that scenario, Kentucky would not be linked to any

maintenance or nonattainment receptors because its

“highest-level contribution” to any such receptor was .84

ppb under that newer modeling. 88 Fed. Reg. at 9356.

Or suppose the EPA relied on the older modeling showing only a single Kentucky link to the Maryland receptor. It might not make much sense to find Kentucky’s

Step 3 analysis inadequate for this receptor. Kentucky’s plan predicted that its then-existing emissions

reductions would allow the Maryland receptor to maintain the new ozone standard. State Plan, J.A. 177-78.

And the EPA’s newer data may well have proved Ken-

44a

tucky right because Kentucky is no longer linked to this

receptor. 2016v3 Modeling, J.A. 577.

In short, we have no idea how the EPA would have

acted if it had not committed the legal errors that we

have identified. The agency thus has failed to show

that the errors did not prejudice Kentucky. Yet nothing we have said in this opinion would prohibit the EPA

from properly raising any new concerns in additional administrative proceedings on remand.

IV.

What Is the Proper Remedy?

Despite the errors underlying its action, the EPA

lastly asks us to remand to the agency without vacating

its disapproval of Kentucky’s plan. Substantial out-ofcircuit caselaw underlies this request. Several courts

have held that they may remand an illegal action to an

agency without vacating the action—allowing the action

to continue to have binding force in the meantime. See

Black Warrior Riverkeeper, Inc. v. U.S. Army Corps of

Eng’rs, 781 F.3d 1271, 1290 (11th Cir. 2015) (collecting

cases); see also 33 Charles A. Wright et al., Federal

Practice and Procedure § 8382, at 289-93 (2d ed. 2018).

Yet the parties cite only one of our own decisions that

has remanded to an agency without vacating its action.

See Sierra Club v. EPA, 60 F.4th 1008, 1021-23 (6th Cir.

2023). There, we did not find the action unlawful and

instead remanded for additional proceedings at the

agency’s request. See id. at 1020-21. So the case says

nothing about whether we may refuse to vacate illegal

actions. The EPA asks us to break new ground.

We need not do so to resolve this case. Even assuming that the APA permits this remand-withoutvacatur remedy, it would not apply to the EPA’s errors.

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The courts that have permitted remand-without-vacatur

relief consider two primary factors when deciding on the

propriety of that relief. See id. at 1022. They first

ask how serious of an error the agency made. See id.

If the agency committed a technical error that it could

easily fix on remand, courts are more likely to keep its

action in place. See id. If, by contrast, the agency

committed a “fundamental” error—such as taking a substantively illegal action or ignoring notice-and-comment

requirements—these courts will not let the action stand.

See Long Island Power Auth. v. FERC, 27 F.4th 705,

717 (D.C. Cir. 2022); Allina Health Servs. v. Sebelius,

746 F.3d 1102, 1110-11 (D.C. Cir. 2014).

The courts that permit a remand-without-vacatur

remedy next ask how disruptive their vacatur would be.

See Sierra Club, 60 F.4th at 1022. If vacatur would,

say, upend years of transactions entered in reliance on

the agency’s action, courts are more likely to keep it in

place. See Am. Great Lakes Ports Ass’n v. Schultz, 962

F.3d 510, 518-19 (D.C. Cir. 2020). If, however, an

agency can point to just the normal uncertainty that follows every vacatur of agency action, courts are more

likely to vacate the action. See Sierra Club, 60 F.4th at

1023; Nat. Res. Def. Council v. Wheeler, 955 F.3d 68, 85

(D.C. Cir. 2020).

Apart from these two factors, courts treat vacatur as

the default and remand without vacatur as the “rare”

remedy. United Steel, Paper & Forestry, Rubber, Mfg.,

Energy, Allied Indus. & Serv. Workers Int’l Union v.

Mine Safety & Health Admin., 925 F.3d 1279, 1287

(D.C. Cir. 2019); see Am. Great Lakes Ports Ass’n, 962

F.3d at 518. And the two factors merely structure the

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inquiry because the proper remedy will depend on all

the equities. See Sierra Club, 60 F.4th at 1022.

The EPA has failed to establish that the equities justify remand without vacatur here. For starters, while

the EPA may try to rely on distinct grounds to fix its

errors on remand, its current disapproval contains a

“fundamental” defect. Allina Health Servs., 746 F.3d

at 1110 (citation omitted).

The agency’s bait-andswitch tactics left Kentucky with the type of “deficient

notice” that has justified vacatur in other cases. Id.

If anything, this case warrants that relief even more because the EPA undercut the Clean Air Act’s “cooperative federalism” structure. Sierra Club, 681 F.3d at

343 (quoting Ellis, 390 F.3d at 467). If we did not vacate its disapproval, the agency would have every “incentive” to take similar shortcuts in the future. Env’t

Def. Fund v. FERC, 2 F.4th 953, 976 (D.C. Cir. 2021).

The EPA has also not shown that vacatur would have

any unusually disruptive effects. See Sierra Club, 60

F.4th at 1023. It asserts that vacatur will bar it from

imposing its federal implementation plan on Kentucky

and thus will delay that plan’s emissions reductions.

Yet the Supreme Court has already indefinitely stayed

the federal plan. See Ohio, 603 U.S. at 300. So the

agency could not enforce its emissions reductions even

if we refused to vacate the disapproval of Kentucky’s

plan. And the EPA’s long delay in acting on this state

plan undercuts any claim that an urgent need exists to

compel Kentucky to reduce its emissions. See Texas,

2023 WL 7204840, at *11. Besides, the EPA’s arguments simply assume the conclusion on the merits:

that Kentucky’s current plan falls short of meeting its

good-neighbor obligations. But “it is far from certain”

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that the EPA will reach that same conclusion on remand.

Env’t Def. Fund, 2 F.4th at 976.

All told, we deny the EPA’s motion to transfer. We

also grant Kentucky’s petitions for review, vacate the

EPA’s disapproval of Kentucky’s state implementation

plan, and remand to the agency for further proceedings

consistent with this opinion.

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_________________

CONCURRENCE

_________________

MURPHY, Circuit Judge, concurring. Our holding

that the Environmental Protection Agency (EPA) acted

arbitrarily and capriciously and our assumption that the

remand-without-vacatur remedy exists allow us to fully

resolve this case. I write this separate concurrence to

highlight two issues that we need not conclusively decide. First, the EPA’s failure to timely act on Kentucky’s state implementation plan may have provided an

independent ground to vacate the EPA’s disapproval

under the Administrative Procedure Act (APA). Second, the validity of the remand-without-vacatur remedy

may depend on the nature of this “vacatur” relief.

I. Did the EPA’s Untimely Disapproval of Kentucky’s Plan Violate the APA?

Apart from barring arbitrary and capricious agency

action, the APA also requires agencies to act “in accordance with law[.]” 5 U.S.C. § 706(2)(A). Kentucky and

the EPA have debated whether the EPA violated this

mandate by disapproving Kentucky’s plan in an untimely manner using data generated after its deadline to

act. I think it may well have done so.

Start with some statutory background. The Clean

Air Act imposes two deadlines on the EPA after a State

submits a plan. The EPA must first decide whether

the plan contains the “information necessary to enable

[the agency] to determine whether the plan submission

complies with the” Act. 42 U.S.C. § 7410(k)(1)(A). The

EPA has no duty to “act on” a plan until it contains this

information. Id. Yet the EPA should make this “[c]om-

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pleteness” finding within 60 days. Id. § 7410(k)(1)(B).

And if the EPA has failed to make the finding “6 months

after” the State submitted the plan, the plan “shall on

that date be deemed by operation of law to meet [the]

minimum criteria” necessary for the EPA’s review. Id.

The second deadline then identifies when the EPA must

approve or disapprove the plan: “[w]ithin 12 months”

of the EPA’s completeness finding (whether made expressly or “by operation of law”). Id. § 7410(k)(2)-(3).

The parties agree on how this law applied here. Kentucky submitted its plan in January 2019. But the EPA

never expressly found that this plan contained all the required information. By operation of law, therefore, that

finding occurred in July 2019. See id. § 7410(k)(1)(B).

This date, in turn, required the EPA to act on Kentucky’s

plan by July 2020. See id. § 7410(k)(2)-(3). But the

EPA missed this deadline. It disapproved the plan

more than two years later in February 2023. What

consequences should follow from the missed deadline?

Background principles help answer this question.

Many statutes command public officials to act within a

certain time. See United States v. James Daniel Good

Real Prop., 510 U.S. 43, 63 (1993). The Supreme Court

has repeatedly held that official s who miss these statutory deadlines do not automatically forfeit the power to

act belatedly if the statute itself does not impose that

penalty. See id.; Nielsen v. Preap, 586 U.S. 392, 411

(2019) (plurality opinion); Barnhart v. Peabody Coal

Co., 537 U.S. 149, 158-63 (2003); Brock v. Pierce County,

476 U.S. 253, 259-62 (1986); see also McIntosh v. United

States, 601 U.S. 330, 337-42 (2024). When a statute

does not identify the consequence for a violation, the

Court has explained, courts may not simply pick the

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remedy they think best as a common-law matter. See

James Daniel Good, 510 U.S. at 63; Gen. Med., P.C. v.

Azar, 963 F.3d 516, 526 (6th Cir. 2020) (Murphy, J., concurring).

These principles provide the first step in the analysis:

The Clean Air Act says nothing about what should happen if the EPA misses its “[d]eadline for action” on a

state plan. 42 U.S.C. § 7410(k)(2). And we cannot create our “own coercive sanction” (say, an automatic approval of the state plan) to remedy the EPA’s untimely

action on the plan. Barnhart, 537 U.S. at 159 (quoting

James Daniel Good, 510 U.S. at 63). Indeed, the Act’s

silence stands out compared to the remedy that applies

when the EPA misses the initial deadline to decide

whether the plan contains all required information. In

that event, the Act “deem[s]” the plan complete “by operation of law[.]” 42 U.S.C. § 7410(k)(1)(B). And

Congress presumably acted intentionally with its inclusion of this express remedy for the first deadline and its

omission of the remedy for the second one. See State

Farm Fire & Cas. Co. v. United States ex rel. Rigsby,

580 U.S. 26, 34 (2016).

As other background principles show, however, this

conclusion does not allow the EPA to violate the Clean

Air Act’s timelines with impunity. Rather, additional

sources of law can allow courts to enforce a statute’s requirements even when the statute itself lacks its own

remedy. As one example from the Supreme Court’s

caselaw, Article III gives courts the “inherent power” to

sanction parties for violating court rules—even if no

statute gives them this power. Id. at 37 (citing Chambers v. NASCO, Inc., 501 U.S. 32, 43-46 (1991)). So

when a statute required plaintiffs to file complaints un-

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der seal, this background power allowed courts to punish plaintiffs who violated the sealing requirement despite the lack of a statutory remedy. See id. If courts

rely on these other remedies, however, they must also

respect the limitations that come with the remedies.

In criminal cases, for instance, district courts must overlook all errors that do not harm the defendant. See

Fed. R. Crim. P. 52(a); McIntosh, 601 U.S. at 338. This

harmless-error rule covers the failure of courts or prosecutors to meet various statutory deadlines in criminal

cases. See Dolan v. United States, 560 U.S. 605, 617

(2010); United States v. Montalvo-Murillo, 495 U.S.

711, 722 (1990).

These principles provide the second step in the analysis: Although the Clean Air Act does not explain what

should happen if the EPA acts on a state plan after its

deadline, the APA applies to this untimely action. And

this second legal source does allow us to “set aside” (and

issue an “injunction” against) an EPA “action” if it is

“not in accordance with” the Clean Air Act’s timelines.

5 U.S.C. §§ 703, 706(2)(A). The EPA also seemingly violated the Clean Air Act’s clear command that it “shall

act on” Kentucky’s plan within 12 months of its completeness finding. 42 U.S.C. § 7410(k)(2). The word

“shall” suggests that the EPA lacks discretion to miss

this deadline. See State Farm, 580 U.S. at 33-34. In

short, courts need not rely on their “own coercive sanction” to remedy violations of the Clean Air Act’s timelines. James Daniel Good, 510 U.S. at 63. They need

only rely on the APA’s sanction for this violation.

That said, like the harmless-error rule in criminal

cases, the APA requires us to give “due account” to “the

rule of prejudicial error.” 5 U.S.C. § 706. If the EPA’s

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violation of the deadline when ruling on Kentucky’s plan

did not harm Kentucky, the APA would give us no basis

to overturn the untimely disapproval. See Shinseki v.

Sanders, 556 U.S. 396, 406-07 (2009). For several reasons, however, the illegal delay may well have “had a

‘substantial influence’ on the outcome of the proceeding”

in this case. Montalvo-Murillo, 495 U.S. at 722 (quoting Bank of Nova Scotia v. United States, 487 U.S. 250,

256 (1988)); see Shinseki, 556 U.S. at 407-08. Those

reasons all follow from the EPA’s decision to base its

untimely disapproval on data in the 2016v3 modeling

that postdated the EPA’s deadline to act. See Air Plan

Disapprovals, 88 Fed. Reg. 9336, 9345 (Feb. 13, 2023).

For starters, the Clean Air Act notes that the EPA

“shall approve” a state plan within the required timeframe if the plan “meets all of the applicable requirements” of the Act. 42 U.S.C. § 7410(k)(3) (emphasis

added). So if the information on the date of the EPA’s

deadline shows that the plan complies with the Act, the

EPA must approve the plan. See id. The Act does not

give the EPA residual discretion. See Ohio v. EPA,

603 U.S. 279, 284 (2024). Given this statutory scheme,

the EPA’s use of after-the-fact data perhaps shows the

required harm to Kentucky.

A related provision confirms this point. The EPA

admits that Kentucky could have sued back in July 2020

to obtain a court order requiring the EPA to timely act

while Kentucky’s plan remained pending with the EPA.

See 42 U.S.C. § 7604(a)(2); 88 Fed. Reg. at 9365; Brock,

476 U.S. at 260 n.7. Yet a court-imposed deadline to

rule on the plan in, say, 2021 would likewise have barred

the EPA from relying on “datasets” that did not exist

until 2022. 88 Fed. Reg. at 9345. As a result, even the

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EPA’s preferred remedy shows that its delay harmed

Kentucky because it allowed the EPA to rely on postdeadline data that Congress did not intend for it to consider. See Motor Vehicle Mfrs. Ass’n of U.S., Inc. v.

State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983).

A structural point reinforces the same idea. The

Clean Air Act does not leave the EPA powerless to consider new information. It provides a remedy when new

facts show that an approved state plan “is substantially

inadequate to attain or maintain” an air-quality standard. 42 U.S.C. § 7410(k)(5). In a paragraph entitled

“[c]alls for plan revisions,” the Act allows the EPA to

“require [a] State to revise” this plan. Id. But such a

compelled amendment requires the EPA to jump

through several procedural hoops. The EPA must notify the State of its concerns, and the State (not the

EPA) gets to take the lead in deciding on the revisions

that will address those concerns. See id. This cooperative process also shows that EPA’s unlawful delay

likely prejudiced Kentucky. If the EPA had taken this

statutorily contemplated path, Kentucky would have retained the authority to devise revisions that accounted

for the EPA’s post-deadline modeling. See id. By delaying action on Kentucky’s plan and then disapproving

it using this modeling, the EPA kicked Kentucky out of

this process by triggering the power to impose a federal

plan. See Ohio, 603 U.S. at 284-86; Texas v. EPA, 2023

WL 7204840, at *9 (5th Cir. May 1, 2023) (per curiam).

As far as I can tell, nothing in the EPA’s briefing justifies its unlawful delay and prejudicial use of post-deadline

data. The agency first cites caselaw holding that agencies

might violate the APA’s ban on arbitrary-and-capricious

conduct if they “ignore new and better data.” Dist.

54a

Hosp. Partners, L.P. v. Burwell, 786 F.3d 46, 56-57

(D.C. Cir. 2015). The EPA thus suggests that it would

have acted arbitrarily if it overlooked the 2016v3 modeling. Yet this caselaw has rejected arbitrary-and-capricious challenges when the EPA had good reasons to use

older data. See Sierra Club v. EPA, 356 F.3d 296, 308

(D.C. Cir. 2004); see also Bd. of Cnty. Comm’rs of Weld

Cnty. v. EPA, 72 F.4th 284, 289-90 (D.C. Cir. 2023).

The EPA perhaps had such reasons here: the Act required it to approve or disapprove the plan in a timely

manner, not to wait on constantly updated modeling.

See Sierra Club, 356 F.3d at 308. To be sure, I agree

that this fact does not mean that the EPA should “ignore” this newer modeling. Dist. Hosp. Partners, 786

F.3d at 57. It just means that the EPA should follow

the Clean Air Act’s rules for how to use it: by issuing

a call for the revision of an approved plan—not by unlawfully postponing its decision on a proposed one.

The EPA next relies on a decision that rejected the

claim that the agency must rely on pollution conditions

as they existed on the deadline for States to submit their

plans. See Wisconsin v. EPA, 938 F.3d 303, 322 (D.C.

Cir. 2019) (per curiam). The EPA places undue emphasis on Wisconsin. There, the EPA proposed a federal plan in 2016 using data about expected pollution

conditions in 2017. See id. at 312, 321. This data revealed that a downwind State (Delaware) would have no

problematic receptors. Id. at 321. But Delaware argued that the Good Neighbor Provision required the

EPA to consider pollution conditions as they existed in

2011. Id. The State relied on the fact that the Act required upwind States to submit their plans for meeting

the relevant air-quality standard at that time. Id. at

321-22. The D.C. Circuit rejected this view. Because

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the Good Neighbor Provision uses the future tense (covering States that “will” contribute to downwind nonattainment), the court interpreted the provision as regulating pollution conditions in future years—not as of the

plan-submission date. Id. at 322 (quoting 42 U.S.C.

§ 7410(a)(2)(D)(i)). Nothing I say here conflicts with this

logic. Both the 2011 modeling that Kentucky used and

the 2016v3 modeling that the EPA used predicted pollution in a future year: 2023. See Mar. Mem., J.A. 77;

88 Fed. Reg. at 9345. Neither source modeled pollution existing when Kentucky submitted its plan in 2019.

And since Wisconsin involved a federal plan, it did not

discuss what should happen if the EPA violates its statutory deadline to rule on a state plan. Wisconsin thus

did not suggest that the EPA could deny a state plan

using new data generated after its deadline to act.

When the EPA turns to the Clean Air Act’s text, it

concedes that the Act imposes a mandatory deadline for

the agency to decide on a plan’s validity. But the EPA

calls the statutory deadline “procedural” and suggests

that it is “not ‘central to the regulatory scheme.’ ” Respondents’ Br. 80 (quoting Wisconsin, 938 F.3d at 322).

The agency adds that it may freely disregard “procedural” rules in pursuit of achieving the “Act’s central object”: attaining the air-quality standard. Id. (quoting Wisconsin, 938 F.3d at 316). I see three problems

with this ends-justify-the-means logic. As an initial

matter, the Constitution does not give agencies any prerogative power to “dispense” with statutory requirements that they find “unimportant.” See Michael W.

McConnell, The President Who Would Not Be King 11519 (2020). Next, because “no legislation pursues its

purposes at all costs,” CTS Corp. v. Waldburger, 573

U.S. 1, 12 (2014) (quoting Rodriguez v. United States,

56a

480 U.S. 522, 525-26 (1987) (per curiam)), the “limitations” on a statute’s main goals are “often [its] price of

passage[.]”

Henson v. Santander Consumer USA

Inc., 582 U.S. 79, 89 (2017). So courts must respect

those limitations just as much as the primary provisions.

See Kucana v. Holder, 558 U.S. 233, 252 (2010). Finally, Congress’s findings reveal that it viewed respect

for state authority as a central goal of the Clean Air Act.

See 42 U.S.C. § 7401(a)(3). And the EPA’s unlawful delay here did not just run afoul of a procedural deadline;

it also undercut the Act’s primary “cooperative federalism” design. Sierra Club v. Korleski, 681 F.3d 342, 343

(6th Cir. 2012) (quoting Ellis v. Gallatin Steel Co., 390

F.3d 461, 467 (6th Cir. 2004)).

All told, the EPA’s untimely disapproval of Kentucky’s plan may have violated the APA for this independent reason. Given that it acted in an arbitrary and

capricious way when disapproving that plan, though, we

need not conclusively resolve the issue.

II. Does the APA Authorize a Remand-WithoutVacatur Remedy?

The EPA has asked us to remand its disapproval of

Kentucky’s plan to the agency for reconsideration without vacating that disapproval. In my view, its arguments about the availability of this remedy have broader

ramifications. The correct answer might turn on a debate about whether the APA permits vacatur of an

agency action as a remedy distinct from an injunction

enjoining the action’s enforcement. Compare Corner

Post, Inc. v. Bd. of Governors of Fed. Rsrv. Sys., 144

S. Ct. 2440, 2460-70 (2024) (Kavanaugh, J., concurring),

with United States v. Texas, 599 U.S. 670, 693-703 (2023)

(Gorsuch, J., concurring in the judgment). The APA

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instructs courts that they “shall” “set aside” agency action found unlawful. 5 U.S.C. § 706(2). What does

this text mean? On the one hand, many have read it to

create a distinct vacatur remedy against agency actions

(rather than an injunction remedy against their enforcement). See Corner Post, 144 S. Ct. at 2462-63 (Kavanaugh, J., concurring) (citing cases); Mila Sohoni, The

Power to Vacate a Rule, 88 Geo. Wash. L. Rev. 1121,

1131-37, 1162-63 (2020). Yet this reading cuts against

the notion that courts may refuse to vacate actions found

illegal. Section 706(2) uses the word “shall” and suggests that courts must vacate illegal actions if the section creates a distinct judicial remedy. See Milk Train,

Inc. v. Veneman, 310 F.3d 747, 757 (D.C. Cir. 2002) (Sentelle, J., dissenting) (quoting Checkosky v. SEC, 23 F.3d

452, 491 (D.C. Cir. 1994) (Randolph, J., concurring)).

On the other hand, others have not read § 706(2)’s

“set aside” text as creating a standalone remedy. See

Texas, 599 U.S. at 695-97 (Gorsuch, J., concurring in the

judgment); Arizona v. Biden, 40 F.4th 375, 396-97 (6th

Cir. 2022) (Sutton, C.J., concurring); John Harrison,

Section 706 of the Administrative Procedure Act Does

Not Call for Universal Injunctions or Other Universal

Remedies, 37 Yale J. Reg. Bull. 37, 41-46 (2020). They

have instead read it as codifying an idea first made famous by Marbury v. Madison, 5 U.S. 137 (1803): that

a court need not give effect to an unlawful rule and may

“disregard[]” it when deciding on the parties’ legal rights.

Id. at 177-78; see Harrison, supra, at 43. Those on this

side of the debate have added that the APA allows courts

to grant only traditional remedies like “declaratory

judgments or writs of prohibitory or mandatory injunction[.]” 5 U.S.C. § 703; see Harrison, supra, at 37.

This differing view might make the remand-without-

58a

vacatur remedy more defensible. If the “vacatur” of an

action amounts to nothing more than an injunction, the

remedy could trigger the equitable discretion that

courts possess when deciding whether to grant that relief. The relief is never “a matter of right” even for

parties with valid claims. Hill v. McDonough, 547 U.S.

573, 584 (2006); see Winter v. Nat. Res. Def. Council,

Inc., 555 U.S. 7, 24 (2008). And notably, courts holding

that they may remand without vacatur have justified

this remedy on the ground that vacatur qualifies as an

“equitable remedy” subject to their discretion. Black

Warrior Riverkeeper, Inc. v. U.S. Army Corps of Eng’rs,

781 F.3d 1271, 1290 (11th Cir. 2015).

At day’s end, our resolution of this case allows us to

avoid these tricky issues. We need not decide whether

we have the power to keep illegal action in place. Even

if we did, the EPA has not justified that remedy on the

facts here. So we also need not decide whether “vacatur” qualifies as a new remedy or as an injunction by another name. Nothing turns on that distinction here.

59a

APPENDIX B

1.

42 U.S.C. 7410 provides:

State implementation plans for national primary and secondary ambient air quality standards

(a)

Adoption of plan by State; submission to Administrator; content of plan; revision; new sources; indirect source review program; supplemental or intermittent control systems

(1) Each State shall, after reasonable notice and

public hearings, adopt and submit to the Administrator,

within 3 years (or such shorter period as the Administrator may prescribe) after the promulgation of a national primary ambient air quality standard (or any revision thereof ) under section 7409 of this title for any

air pollutant, a plan which provides for implementation,

maintenance, and enforcement of such primary standard in each air quality control region (or portion thereof )

within such State. In addition, such State shall adopt

and submit to the Administrator (either as a part of a

plan submitted under the preceding sentence or separately) within 3 years (or such shorter period as the Administrator may prescribe) after the promulgation of a

national ambient air quality secondary standard (or revision thereof ), a plan which provides for implementation, maintenance, and enforcement of such secondary

standard in each air quality control region (or portion

thereof ) within such State. Unless a separate public

hearing is provided, each State shall consider its plan

implementing such secondary standard at the hearing

required by the first sentence of this paragraph.

60a

(2) Each implementation plan submitted by a State

under this chapter shall be adopted by the State after

reasonable notice and public hearing. Each such plan

shall—

(A) include enforceable emission limitations and

other control measures, means, or techniques (including economic incentives such as fees, marketable

permits, and auctions of emissions rights), as well as

schedules and timetables for compliance, as may be

necessary or appropriate to meet the applicable requirements of this chapter;

(B) provide for establishment and operation of

appropriate devices, methods, systems, and procedures necessary to—

(i) monitor, compile, and analyze data on ambient air quality, and

(ii) upon request, make such data available to

the Administrator;

(C) include a program to provide for the enforcement of the measures described in subparagraph (A), and regulation of the modification and construction of any stationary source within the areas

covered by the plan as necessary to assure that national ambient air quality standards are achieved, including a permit program as required in parts C and

D;

(D)

contain adequate provisions—

(i) prohibiting, consistent with the provisions of this subchapter, any source or other type

of emissions activity within the State from emitting any air pollutant in amounts which will—

61a

(I) contribute significantly to nonattainment in, or interfere with maintenance by, any

other State with respect to any such national

primary or secondary ambient air quality

standard, or

(II) interfere with measures required to be

included in the applicable implementation plan

for any other State under part C to prevent significant deterioration of air quality or to protect visibility,

(ii) insuring compliance with the applicable

requirements of sections 7426 and 7415 of this title (relating to interstate and international pollution abatement);

(E) provide (i) necessary assurances that the

State (or, except where the Administrator deems inappropriate, the general purpose local government

or governments, or a regional agency designated by

the State or general purpose local governments for

such purpose) will have adequate personnel, funding,

and authority under State (and, as appropriate, local)

law to carry out such implementation plan (and is not

prohibited by any provision of Federal or State law

from carrying out such implementation plan or portion thereof ), (ii) requirements that the State comply

with the requirements respecting State boards under section 7428 of this title, and (iii) necessary assurances that, where the State has relied on a local or

regional government, agency, or instrumentality for

the implementation of any plan provision, the State

has responsibility for ensuring adequate implementation of such plan provision;

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(F) require, as may be prescribed by the

Administrator—

(i) the installation, maintenance, and replacement of equipment, and the implementation

of other necessary steps, by owners or operators

of stationary sources to monitor emissions from

such sources,

(ii) periodic reports on the nature and

amounts of emissions and emissions-related data

from such sources, and

(iii) correlation of such reports by the State

agency with any emission limitations or standards

established pursuant to this chapter, which reports shall be available at reasonable times for

public inspection;

(G) provide for authority comparable to that

in section 7603 of this title and adequate contingency plans to implement such authority;

(H)

provide for revision of such plan—

(i) from time to time as may be necessary to

take account of revisions of such national primary

or secondary ambient air quality standard or the

availability of improved or more expeditious methods of attaining such standard, and

(ii) except as provided in paragraph (3)(C),

whenever the Administrator finds on the basis of

information available to the Administrator that

the plan is substantially inadequate to attain the

national ambient air quality standard which it implements or to otherwise comply with any addi-

63a

tional requirements established under this chapter;

(I)

in the case of a plan or plan revision for an

area designated as a nonattainment area, meet the

applicable requirements of part D (relating to nonattainment areas);

(J) meet the applicable requirements of section

7421 of this title (relating to consultation), section

7427 of this title (relating to public notification), and

part C (relating to prevention of significant deterioration of air quality and visibility protection);

(K)

provide for—

(i) the performance of such air quality modeling as the Administrator may prescribe for the

purpose of predicting the effect on ambient air

quality of any emissions of any air pollutant for

which the Administrator has established a national ambient air quality standard, and

(ii) the submission, upon request, of data related to such air quality modeling to the Administrator;

(L) require the owner or operator of each major

stationary source to pay to the permitting authority,

as a condition of any permit required under this chapter, a fee sufficient to cover—

(i) the reasonable costs of reviewing and acting upon any application for such a permit, and

(ii) if the owner or operator receives a permit

for such source, the reasonable costs of implementing and enforcing the terms and conditions of

any such permit (not including any court costs or

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other costs associated with any enforcement action),

until such fee requirement is superseded with respect

to such sources by the Administrator’s approval of a

fee program under subchapter V; and

(M) provide for consultation and participation

by local political subdivisions affected by the plan.

(3)(A) Repealed. Pub. L. 101-549, title I, § 101(d)(1),

Nov. 15, 1990, 104 Stat. 2409.

(B) As soon as practicable, the Administrator shall,

consistent with the purposes of this chapter and the Energy Supply and Environmental Coordination Act of

1974 [15 U.S.C. 791 et seq.], review each State’s applicable implementation plans and report to the State on

whether such plans can be revised in relation to fuel

burning stationary sources (or persons supplying fuel to

such sources) without interfering with the attainment

and maintenance of any national ambient air quality

standard within the period permitted in this section. If

the Administrator determines that any such plan can be

revised, he shall notify the State that a plan revision may

be submitted by the State. Any plan revision which is

submitted by the State shall, after public notice and opportunity for public hearing, be approved by the Administrator if the revision relates only to fuel burning stationary sources (or persons supplying fuel to such

sources), and the plan as revised complies with paragraph (2) of this subsection. The Administrator shall

approve or disapprove any revision no later than three

months after its submission.

(C) Neither the State, in the case of a plan (or portion thereof ) approved under this subsection, nor the

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Administrator, in the case of a plan (or portion thereof )

promulgated under subsection (c), shall be required to

revise an applicable implementation plan because one or

more exemptions under section 7418 of this title (relating to Federal facilities), enforcement orders under section 7413(d)1 of this title, suspensions under subsection

(f ) or (g) (relating to temporary energy or economic authority), orders under section 7419 of this title (relating to primary nonferrous smelters), or extensions of

compliance in decrees entered under section 7413(e) 1 of

this title (relating to iron- and steel-producing operations) have been granted, if such plan would have met

the requirements of this section if no such exemptions,

orders, or extensions had been granted.

(4) Repealed. Pub. L. 101-549, title I, § 101(d)(2),

Nov. 15, 1990, 104 Stat. 2409.

(5)(A)(i) Any State may include in a State implementation plan, but the Administrator may not require as a

condition of approval of such plan under this section, any

indirect source review program. The Administrator

may approve and enforce, as part of an applicable implementation plan, an indirect source review program

which the State chooses to adopt and submit as part of

its plan.

(ii) Except as provided in subparagraph (B), no

plan promulgated by the Administrator shall include

any indirect source review program for any air quality

control region, or portion thereof.

(iii) Any State may revise an applicable implementation plan approved under this subsection to suspend

1

See References in Text note below.

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or revoke any such program included in such plan, provided that such plan meets the requirements of this section.

(B) The Administrator shall have the authority to

promulgate, implement and enforce regulations under

subsection (c) respecting indirect source review programs which apply only to federally assisted highways,

airports, and other major federally assisted indirect

sources and federally owned or operated indirect

sources.

(C) For purposes of this paragraph, the term “indirect source” means a facility, building, structure, installation, real property, road, or highway which attracts, or

may attract, mobile sources of pollution. Such term includes parking lots, parking garages, and other facilities

subject to any measure for management of parking supply (within the meaning of subsection (c)(2)(D)(ii)), including regulation of existing off-street parking but

such term does not include new or existing on-street

parking. Direct emissions sources or facilities at, within, or associated with, any indirect source shall not be

deemed indirect sources for the purpose of this paragraph.

(D) For purposes of this paragraph the term “indirect source review program” means the facility-by-facility

review of indirect sources of air pollution, including such

measures as are necessary to assure, or assist in assuring, that a new or modified indirect source will not attract mobile sources of air pollution, the emissions from

which would cause or contribute to air pollution concentrations—

67a

(i)

exceeding any national primary ambient air

quality standard for a mobile source-related air pollutant after the primary standard attainment date, or

(ii) preventing maintenance of any such standard after such date.

(E) For purposes of this paragraph and paragraph

(2)(B), the term “transportation control measure” does

not include any measure which is an “indirect source review program”.

(6) No State plan shall be treated as meeting the

requirements of this section unless such plan provides

that in the case of any source which uses a supplemental,

or intermittent control system for purposes of meeting

the requirements of an order under section 7413(d)2 of

this title or section 7419 of this title (relating to primary nonferrous smelter orders), the owner or operator

of such source may not temporarily reduce the pay of

any employee by reason of the use of such supplemental

or intermittent or other dispersion dependent control

system.

(b)

Extension of period for submission of plans

The Administrator may, wherever he determines

necessary, extend the period for submission of any plan

or portion thereof which implements a national secondary ambient air quality standard for a period not to exceed 18 months from the date otherwise required for

submission of such plan.

2

See References in Text note below.

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(c)

Preparation and publication by Administrator of

proposed regulations setting forth implementation

plan; transportation regulations study and report;

parking surcharge; suspension authority; plan implementation

(1) The Administrator shall promulgate a Federal

implementation plan at any time within 2 years after the

Administrator—

(A) finds that a State has failed to make a required submission or finds that the plan or plan revision submitted by the State does not satisfy the minimum criteria established under subsection (k)(1)(A),

or

(B) disapproves a State implementation plan

submission in whole or in part,

unless the State corrects the deficiency, and the Administrator approves the plan or plan revision, before the

Administrator promulgates such Federal implementation plan.

(2)(A) Repealed. Pub. L. 101-549, title I, § 101(d)(3)(A),

Nov. 15, 1990, 104 Stat. 2409.

(B) No parking surcharge regulation may be required by the Administrator under paragraph (1) of this

subsection as a part of an applicable implementation

plan. All parking surcharge regulations previously required by the Administrator shall be void upon June 22,

1974. This subparagraph shall not prevent the Administrator from approving parking surcharges if they are

adopted and submitted by a State as part of an applicable implementation plan. The Administrator may not

condition approval of any implementation plan submit-

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ted by a State on such plan’s including a parking surcharge regulation.

(C) Repealed. Pub. L. 101-549, title I, § 101(d)(3)(B),

Nov. 15, 1990, 104 Stat. 2409.

(D) For purposes of this paragraph—

(i)

The term “parking surcharge regulation”

means a regulation imposing or requiring the imposition of any tax, surcharge, fee, or other charge on

parking spaces, or any other area used for the temporary storage of motor vehicles.

(ii) The term “management of parking supply”

shall include any requirement providing that any new

facility containing a given number of parking spaces

shall receive a permit or other prior approval, issuance of which is to be conditioned on air quality considerations.

(iii) The term “preferential bus/carpool lane”

shall include any requirement for the setting aside of

one or more lanes of a street or highway on a permanent or temporary basis for the exclusive use of buses

or carpools, or both.

(E) No standard, plan, or requirement, relating to

management of parking supply or preferential bus/

carpool lanes shall be promulgated after June 22, 1974,

by the Administrator pursuant to this section, unless

such promulgation has been subjected to at least one

public hearing which has been held in the area affected

and for which reasonable notice has been given in such

area. If substantial changes are made following public

hearings, one or more additional hearings shall be held

in such area after such notice.

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(3) Upon application of the chief executive officer of

any general purpose unit of local government, if the Administrator determines that such unit has adequate authority under State or local law, the Administrator may

delegate to such unit the authority to implement and enforce within the jurisdiction of such unit any part of a

plan promulgated under this subsection. Nothing in

this paragraph shall prevent the Administrator from implementing or enforcing any applicable provision of a

plan promulgated under this subsection.

(4) Repealed. Pub. L. 101-549, title I, § 101(d)(3)(C),

Nov. 15, 1990, 104 Stat. 2409.

(5)(A) Any measure in an applicable implementation plan which requires a toll or other charge for the

use of a bridge located entirely within one city shall be

eliminated from such plan by the Administrator upon

application by the Governor of the State, which application shall include a certification by the Governor that he

will revise such plan in accordance with subparagraph

(B).

(B) In the case of any applicable implementation

plan with respect to which a measure has been eliminated under subparagraph (A), such plan shall, not later

than one year after August 7, 1977, be revised to include

comprehensive measures to:

(i)

establish, expand, or improve public transportation measures to meet basic transportation

needs, as expeditiously as is practicable; and

(ii) implement transportation control measures

necessary to attain and maintain national ambient air

quality standards,

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and such revised plan shall, for the purpose of implementing such comprehensive public transportation

measures, include requirements to use (insofar as is necessary) Federal grants, State or local funds, or any combination of such grants and funds as may be consistent

with the terms of the legislation providing such grants

and funds. Such measures shall, as a substitute for the

tolls or charges eliminated under subparagraph (A),

provide for emissions reductions equivalent to the reductions which may reasonably be expected to be

achieved through the use of the tolls or charges eliminated.

(C) Any revision of an implementation plan for purposes of meeting the requirements of subparagraph (B)

shall be submitted in coordination with any plan revision

required under part D.

(d), (e) Repealed. Pub. L. 101-549, title I, § 101(d)(4),

(5), Nov. 15, 1990, 104 Stat. 2409

(f )

National or regional energy emergencies; determination by President

(1) Upon application by the owner or operator of a

fuel burning stationary source, and after notice and opportunity for public hearing, the Governor of the State

in which such source is located may petition the President to determine that a national or regional energy

emergency exists of such severity that—

(A) a temporary suspension of any part of the

applicable implementation plan or of any requirement under section 7651j of this title (concerning

excess emissions penalties or offsets) may be necessary, and

72a

(B) other means of responding to the energy

emergency may be inadequate.

Such determination shall not be delegable by the President to any other person. If the President determines

that a national or regional energy emergency of such severity exists, a temporary emergency suspension of any

part of an applicable implementation plan or of any requirement under section 7651j of this title (concerning

excess emissions penalties or offsets) adopted by the

State may be issued by the Governor of any State covered by the President’s determination under the condition specified in paragraph (2) and may take effect immediately.

(2) A temporary emergency suspension under this

subsection shall be issued to a source only if the Governor of such State finds that—

(A) there exists in the vicinity of such source a

temporary energy emergency involving high levels of

unemployment or loss of necessary energy supplies

for residential dwellings; and

(B) such unemployment or loss can be totally or

partially alleviated by such emergency suspension.

Not more than one such suspension may be issued for

any source on the basis of the same set of circumstances

or on the basis of the same emergency.

(3) A temporary emergency suspension issued by a

Governor under this subsection shall remain in effect for

a maximum of four months or such lesser period as may

be specified in a disapproval order of the Administrator,

if any. The Administrator may disapprove such suspension if he determines that it does not meet the requirements of paragraph (2).

73a

(4) This subsection shall not apply in the case of a

plan provision or requirement promulgated by the Administrator under subsection (c) of this section, but in

any such case the President may grant a temporary emergency suspension for a four month period of any such

provision or requirement if he makes the determinations

and findings specified in paragraphs (1) and (2).

(5) The Governor may include in any temporary

emergency suspension issued under this subsection a

provision delaying for a period identical to the period of

such suspension any compliance schedule (or increment

of progress) to which such source is subject under section 1857c-102 of this title, as in effect before August 7,

1977, or section 7413(d) 2 of this title, upon a finding that

such source is unable to comply with such schedule (or

increment) solely because of the conditions on the basis

of which a suspension was issued under this subsection.

(g)

Governor’s authority to issue temporary emergency

suspensions

(1) In the case of any State which has adopted and

submitted to the Administrator a proposed plan revision

which the State determines—

(A)

meets the requirements of this section, and

(B) is necessary (i) to prevent the closing for one

year or more of any source of air pollution, and (ii) to

prevent substantial increases in unemployment which

would result from such closing, and

which the Administrator has not approved or disapproved under this section within 12 months of submission of the proposed plan revision, the Governor may issue a temporary emergency suspension of the part of

the applicable implementation plan for such State which

74a

is proposed to be revised with respect to such source.

The determination under subparagraph (B) may not be

made with respect to a source which would close without

regard to whether or not the proposed plan revision is

approved.

(2) A temporary emergency suspension issued by a

Governor under this subsection shall remain in effect for

a maximum of four months or such lesser period as may

be specified in a disapproval order of the Administrator.

The Administrator may disapprove such suspension if

he determines that it does not meet the requirements of

this subsection.

(3) The Governor may include in any temporary

emergency suspension issued under this subsection a

provision delaying for a period identical to the period of

such suspension any compliance schedule (or increment

of progress) to which such source is subject under section 1857c-1033of this title as in effect before August 7,

1977, or under section 7413(d)3 of this title upon a finding that such source is unable to comply with such schedule (or increment) solely because of the conditions on the

basis of which a suspension was issued under this subsection.

(h)

Publication of comprehensive document for each

State setting forth requirements of applicable implementation plan

(1) Not later than 5 years after November 15, 1990,

and every 3 years thereafter, the Administrator shall assemble and publish a comprehensive document for each

State setting forth all requirements of the applicable im3

See References in Text note below.

75a

plementation plan for such State and shall publish notice

in the Federal Register of the availability of such documents.

(2) The Administrator may promulgate such regulations as may be reasonably necessary to carry out the

purpose of this subsection.

(i)

Modification of requirements prohibited

Except for a primary nonferrous smelter order under section 7419 of this title, a suspension under subsection (f ) or (g) (relating to emergency suspensions), an

exemption under section 7418 of this title (relating to

certain Federal facilities), an order under section

7413(d)3 of this title (relating to compliance orders), a

plan promulgation under subsection (c), or a plan revision under subsection (a)(3); no order, suspension, plan

revision, or other action modifying any requirement of

an applicable implementation plan may be taken with respect to any stationary source by the State or by the Administrator.

( j)

Technological systems of continuous emission reduction on new or modified stationary sources; compliance with performance standards

As a condition for issuance of any permit required under this subchapter, the owner or operator of each new

or modified stationary source which is required to obtain

such a permit must show to the satisfaction of the permitting authority that the technological system of continuous emission reduction which is to be used at such

source will enable it to comply with the standards of performance which are to apply to such source and that the

construction or modification and operation of such

76a

source will be in compliance with all other requirements

of this chapter.

(k)

Environmental Protection Agency action on plan

submissions

(1) Completeness of plan submissions

(A)

Completeness criteria

Within 9 months after November 15, 1990, the

Administrator shall promulgate minimum criteria

that any plan submission must meet before the

Administrator is required to act on such submission under this subsection. The criteria shall be

limited to the information necessary to enable the

Administrator to determine whether the plan submission complies with the provisions of this chapter.

(B)

Completeness finding

Within 60 days of the Administrator’s receipt

of a plan or plan revision, but no later than 6

months after the date, if any, by which a State is

required to submit the plan or revision, the Administrator shall determine whether the minimum

criteria established pursuant to subparagraph (A)

have been met. Any plan or plan revision that a

State submits to the Administrator, and that has

not been determined by the Administrator (by the

date 6 months after receipt of the submission) to

have failed to meet the minimum criteria established pursuant to subparagraph (A), shall on that

date be deemed by operation of law to meet such

minimum criteria.

77a

(C)

Effect of finding of incompleteness

Where the Administrator determines that a

plan submission (or part thereof ) does not meet

the minimum criteria established pursuant to subparagraph (A), the State shall be treated as not

having made the submission (or, in the Administrator’s discretion, part thereof ).

(2) Deadline for action

Within 12 months of a determination by the Administrator (or a determination deemed by operation

of law) under paragraph (1) that a State has submitted a plan or plan revision (or, in the Administrator’s

discretion, part thereof ) that meets the minimum criteria established pursuant to paragraph (1), if applicable (or, if those criteria are not applicable, within

12 months of submission of the plan or revision), the

Administrator shall act on the submission in accordance with paragraph (3).

(3) Full and partial approval and disapproval

In the case of any submittal on which the Administrator is required to act under paragraph (2), the

Administrator shall approve such submittal as a

whole if it meets all of the applicable requirements of

this chapter. If a portion of the plan revision meets

all the applicable requirements of this chapter, the

Administrator may approve the plan revision in part

and disapprove the plan revision in part. The plan

revision shall not be treated as meeting the requirements of this chapter until the Administrator approves the entire plan revision as complying with the

applicable requirements of this chapter.

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(4) Conditional approval

The Administrator may approve a plan revision

based on a commitment of the State to adopt specific

enforceable measures by a date certain, but not later

than 1 year after the date of approval of the plan revision.

Any such conditional approval shall be

treated as a disapproval if the State fails to comply

with such commitment.

(5) Calls for plan revisions

Whenever the Administrator finds that the applicable implementation plan for any area is substantially inadequate to attain or maintain the relevant

national ambient air quality standard, to mitigate adequately the interstate pollutant transport described

in section 7506a of this title or section 7511c of this

title, or to otherwise comply with any requirement of

this chapter, the Administrator shall require the

State to revise the plan as necessary to correct such

inadequacies. The Administrator shall notify the

State of the inadequacies, and may establish reasonable deadlines (not to exceed 18 months after the date

of such notice) for the submission of such plan revisions. Such findings and notice shall be public.

Any finding under this paragraph shall, to the extent

the Administrator deems appropriate, subject the

State to the requirements of this chapter to which the

State was subject when it developed and submitted

the plan for which such finding was made, except that

the Administrator may adjust any dates applicable

under such requirements as appropriate (except that

the Administrator may not adjust any attainment

date prescribed under part D, unless such date has

elapsed).

79a

(6) Corrections

Whenever the Administrator determines that

the Administrator’s action approving, disapproving,

or promulgating any plan or plan revision (or part

thereof ), area designation, redesignation, classification, or reclassification was in error, the Administrator may in the same manner as the approval, disapproval, or promulgation revise such action as appropriate without requiring any further submission from

the State. Such determination and the basis thereof

shall be provided to the State and public.

(l)

Plan revisions

Each revision to an implementation plan submitted

by a State under this chapter shall be adopted by such

State after reasonable notice and public hearing. The

Administrator shall not approve a revision of a plan if

the revision would interfere with any applicable requirement concerning attainment and reasonable further

progress (as defined in section 7501 of this title), or any

other applicable requirement of this chapter.

(m) Sanctions

The Administrator may apply any of the sanctions

listed in section 7509(b) of this title at any time (or at

any time after) the Administrator makes a finding, disapproval, or determination under paragraphs (1) through

(4), respectively, of section 7509(a) of this title in relation to any plan or plan item (as that term is defined by

the Administrator) required under this chapter, with respect to any portion of the State the Administrator determines reasonable and appropriate, for the purpose of

ensuring that the requirements of this chapter relating

to such plan or plan item are met. The Administrator

80a

shall, by rule, establish criteria for exercising his authority under the previous sentence with respect to any

deficiency referred to in section 7509(a) of this title to

ensure that, during the 24-month period following the

finding, disapproval, or determination referred to

in section 7509(a) of this title, such sanctions are not applied on a statewide basis where one or more political

subdivisions covered by the applicable implementation

plan are principally responsible for such deficiency.

(n)

Savings clauses

(1) Existing plan provisions

Any provision of any applicable implementation

plan that was approved or promulgated by the Administrator pursuant to this section as in effect before November 15, 1990, shall remain in effect as part

of such applicable implementation plan, except to the

extent that a revision to such provision is approved

or promulgated by the Administrator pursuant to

this chapter.

(2) Attainment dates

For any area not designated nonattainment, any

plan or plan revision submitted or required to be submitted by a State—

(A) in response to the promulgation or revision of a national primary ambient air quality

standard in effect on November 15, 1990, or

(B) in response to a finding of substantial inadequacy under subsection (a)(2) (as in effect immediately before November 15, 1990),

shall provide for attainment of the national primary

ambient air quality standards within 3 years of No-

81a

vember 15, 1990, or within 5 years of issuance of such

finding of substantial inadequacy, whichever is later.

(3) Retention of construction moratorium in certain

areas

In the case of an area to which, immediately before

November 15, 1990, the prohibition on construction

or modification of major stationary sources prescribed

in subsection (a)(2)(I) (as in effect immediately before November 15, 1990) applied by virtue of a finding of the Administrator that the State containing

such area had not submitted an implementation plan

meeting the requirements of section 7502(b)(6) of

this title (relating to establishment of a permit program) (as in effect immediately before November 15,

1990) or 7502(a)(1) of this title (to the extent such requirements relate to provision for attainment of the

primary national ambient air quality standard for

sulfur oxides by December 31, 1982) as in effect immediately before November 15, 1990, no major stationary source of the relevant air pollutant or pollutants shall be constructed or modified in such area

until the Administrator finds that the plan for such

area meets the applicable requirements of section

7502(c)(5) of this title (relating to permit programs)

or subpart 5 of part D (relating to attainment of the

primary national ambient air quality standard for

sulfur dioxide), respectively.

(o)

Indian tribes

If an Indian tribe submits an implementation plan to

the Administrator pursuant to section 7601(d) of this title, the plan shall be reviewed in accordance with the

provisions for review set forth in this section for State

82a

plans, except as otherwise provided by regulation promulgated pursuant to section 7601(d)(2) of this title.

When such plan becomes effective in accordance with

the regulations promulgated under section 7601(d) of

this title, the plan shall become applicable to all areas

(except as expressly provided otherwise in the plan) located within the exterior boundaries of the reservation,

notwithstanding the issuance of any patent and including rights-of-way running through the reservation.

(p)

Reports

Any State shall submit, according to such schedule as

the Administrator may prescribe, such reports as the

Administrator may require relating to emission reductions, vehicle miles traveled, congestion levels, and any

other information the Administrator may deem necessary to assess the development 4 effectiveness, need for

revision, or implementation of any plan or plan revision

required under this chapter.

4

So in original.

Probably should be followed by a comma.

83a

2.

42 U.S.C. 7607(b)(1) provides:

Administrative proceedings and judicial review

(b)

Judicial review

(1) A petition for review of action of the Administrator in promulgating any national primary or secondary

ambient air quality standard, any emission standard or

requirement under section 7412 of this title, any standard of performance or requirement under section 7411

of this title,,35any standard under section 7521 of this title (other than a standard required to be prescribed under section 7521(b)(1) of this title), any determination

under section 7521(b)(5) 1 6 of this title, any control or

prohibition under section 7545 of this title, any standard under section 7571 of this title, any rule issued under section 7413, 7419, or under section 7420 of this title, or any other nationally applicable regulations promulgated, or final action taken, by the Administrator under this chapter may be filed only in the United States

Court of Appeals for the District of Columbia. A petition for review of the Administrator’s action in approving or promulgating any implementation plan under section 7410 of this title or section 7411(d) of this title, any

order under section 7411( j) of this title, under section

7412 of this title, under section 7419 of this title, or under section 7420 of this title, or his action under section

1857c-10(c)(2)(A), (B), or (C) of this title (as in effect before August 7, 1977) or under regulations thereunder,

or revising regulations for enhanced monitoring and

compliance certification programs under section

7414(a)(3) of this title, or any other final action of the

1

3

See References in Text note below.

So in original.

84a

Administrator under this chapter (including any denial

or disapproval by the Administrator under subchapter

I) which is locally or regionally applicable may be filed

only in the United States Court of Appeals for the appropriate circuit. Notwithstanding the preceding sentence a petition for review of any action referred to in

such sentence may be filed only in the United States

Court of Appeals for the District of Columbia if such

action is based on a determination of nationwide scope

or effect and if in taking such action the Administrator

finds and publishes that such action is based on such a

determination. Any petition for review under this

subsection shall be filed within sixty days from the date

notice of such promulgation, approval, or action appears

in the Federal Register, except that if such petition is

based solely on grounds arising after such sixtieth day,

then any petition for review under this subsection shall

be filed within sixty days after such grounds arise.

The filing of a petition for reconsideration by the Administrator of any otherwise final rule or action shall

not affect the finality of such rule or action for purposes

of judicial review nor extend the time within which a petition for judicial review of such rule or action under this

section may be filed, and shall not postpone the effectiveness of such rule or action.