Petitioners Brief — Whitman v. American Trucking Assns., Inc.

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7— 2°, Avo © !

No. 99-1257

In the Supreme Court of the United States

CAROL M. BROWNER, ADMINISTRATOR OF

THE ENVIRONMENTAL PROTECTION AGENCY,

ET AL., PETITIONERS

AMERICAN TRUCKING ASSOCIATIONS, INC., ET AL.

ON A WRIT OF CERTIORARI TO

THE UNITED STATES COURT OF APPEALS

FOR THE DISTRICT OF COLUMBIA CIRCUIT

BRIEF FOR THE PETITIONERS

SETH P. WAXMAN

Solicitor General

Counsel of Record

Lois J. SCHIFFER

Assistant Attorney General

LAWRENCE G. WALLACE

Gary S. Guzy Deputy Solicitor General

General Counsel JEFFREY P. MIN EAR

GERALD K. GLEASON Assistant to the Solicitor

MICHAEL L. Goo General

JAN M. TIERNEY DAVID J. KAPLAN

KEVIN W. MCLEAN MARY F. EDGAR

Attorneys Attorneys

Environmental Protection Department of Justice

Agency Washington, D.C. 20530-0001

Washington, D.C. 20460 (202) 514-2217

QUESTIONS PRESENTED

1. Whether Section 109 of the Clean Air Act (CAA), 42

U.S.C. 7409, as interpreted by the Environmental Protection

Agency (EPA) in setting revised National Ambient Air

Quality Standards (NAAQS) for ozone and particulate

matter, effects an unconstitutional delegation of legislative

power.

2. Whether the court of appeals exceeded its jurisdiction

by reviewing, as a final agency action that is ripe for review,

EPA’s preliminary preamble statements on the scope of the

agency’s authority to implement the revised “eight-hour”

ozone NAAQS.

3. Whether provisions of the Clean Air Act Amendments

of 1990 specifically aimed at achieving the long-delayed

attainment of the then-existing ozone NAAQS restrict

EPA’s general authority under other provisions of the CAA

to implement a new and more protective ozone NAAQS until

the prior standard is attained.

(I)

2 TT ee EFL — — m

„

TABLE OF CONTENTS

Opinions below

Jurisdiction

Constitutional, statutory, and regulatory provisions in-

volved.

Statement

I. The Clean Air Act’s NAAQS provisions

A. Air quality criteria and standards

B. Implementation of air quality standards .............

II. The particulate matter and ozone rulemaking

proceedings

A. The particulate matter rule

B. The ozone rule

III. The proceedings below

Summary of argument

Argument:

I. The court of appeals erroneously applied the

nondelegation doctrine

A. Section 109 of the Clean Air Act does not

constitute an unconstitutional grant of

legislative power

B. The court of appeals improperly employed

the nondelegation doctrine to expand the

scope of its review

C. EPA has recognized limitations on its

discretion to revise the particulate matter and

ozone standards

II. The court of appeals lacked jurisdiction to review

| EPA’s preamble statements on the scope of its

authority to implement a revised ozone

' standard

(III)

Table of Contents—Continued:

A. EPA’s preamble statements regarding imple-

mentation authority are not “agency action”

within the meaing of Section 307(b)(1) of

the Act

B. EPA’s preamble statements do not constitute

“final” agency action

C. EPA’s preamble statements regarding imple-

mentation of the eight-hour ozone standard

are not ripe for review

III. The court of appeals improperly restricted

EPA’s authority to implement the revised

ozone standard

A. The Clean Air Act authorizes EPA to

implement the revised ozone NAAQS under

Subpart 1 of Part D

B. Delaying implementation of the revised

NAAQS until the previous standard is

attained conflicts with the Clean Air Act’s

requirement that all NAAQS be attained “as

expeditiously as practicable”

Conclusion

Appendix

TABLE OF AUTHORITIES

Cases:

ACLU v. FCC, 823 F.2d 1554 (D.C. Cir. 1987),

Abbott Labs. v. Gardner, 387 U.S. 136 (1967) ......... 38. 41. 42

cert. denied, 485 U.S. 959 (1988)

American Power & Light Co. v. SEC, 329 U.S. 90

» 8 8

(1946) 22, 24, 26, 27

Baltimore Gas & Elec. Co. v. NRDC, 462 U.S. 87

(1983)

Cases Continued: Page

Bennett v. Spear, 520 U.S. 154 (1997) 38, 41

Black v. Cutter Labs., 351 U.S. 292 (1956) 37

California v. Rooney, 483 U.S. 307 (1987) .. 37

Chevron U.S.A. Inc. v. NRDC, 467 U.S. 837

(1984) 43, 48, 50

Citizens to Preserve Overton Park, Inc. v. Volpe,

401 U.S. 402 (1971) 27, 34

Ethyl Corp. v. EPA, 541 F.2d 1 (D.C. Cir.), cert.

denied, 426 U.S. 941 (1976) 28

FPC v. Conway Corp, 426 U.S. 271 (1976) 30

FTC v. Mandel Bros., Inc., 359 U.S. 385 (1959) ............... 46

FTC v. Standard Oil Co., 449 U.S. 232 (1980) .............. 36, 37,

38, 43

Federal Energy Admin. v. Algonquin SNG,

Inc., 426 U.S. 548 (1976) 25, 26

Harrison v. PPG Indus., Inc., 446 U.S. 578

(1980) 36

Herb v. Pitcairn, 324 US. 117 (1945) 37

INS v. National Ctr. for Immigrants Rights,

Inc., 502 U.S. 183 (1991) 46

International Longshoremen s & Warehousemen’s

Union v. Boyd, 347 U.S. 222 (1954) 43

Lead Indus. Ass n v. EPA, 647 F 2d 1130 (D.C.

Cir.), cert. denied, 449 U.S. 1042 (1980) 3, 5, 24, 29

Loving v. United States, 517 U.S. 748 (1998) 21

Lujan v. National Wildlife Fed’n, 497 U.S. 871

(1990) 36, 44

Mead Corp. v. Tilley, 490 U.S. 714 (1989) * 46

Mistretta v. United States, 488 U.S. 361 (1989) ............ 21, 22,

23, 24, 25, 44

Montana-Dakota Util. Co. v. Northwestern Pub.

II 30

Cases Continued: Page

NR De v. EPA, 902 F. 2d 962 (1990), opinion vacated

in part, 921 F. 2d 326 (D.C. Cir.), cert. denied, 498

U.S. 1082 (1991) 4, 28, 30

New York v. EPA, 852 F. 2d 574 (D.C. Cir. 1988),

cert. denied, 489 U.S. 1065 (1989) 28

Office of Communication of United Church of

Christ v. FCC, 826 F.2d 101 (D.C. Cir. 1987) .. 43

Ohio Forestry Ass n v. Sierra Club, 523 U.S. 726

(1998) 41, 42, 43, 44

Poe v. Ullman, 367 U.S. 497 (1961) —— . ͤ 42

Reno v. Catholic Soc. Servs., Inc., 509 U.S. 43

(1993) 4142

Simon v. Eastern Ky. Welfare Rights Org., 426

I ___—————————————————————— 42

Skinner v. Mid-America Pipeline Co., 490 U.S.

212 (1989) 22

Texas v. United States, 523 U.S. 296 (1998) 42

Toilet Goods Ass’n v. Gardner, 387 U.S. 158

(1967) 43, 44

Touby v. United States, 500 U.S. 160 (1991) ........... 21, 24, 25

Train v. NRDC, 421 US. 60 (1975)... 3,6

Union Elec. Co. v. EPA, 427 U.S. 246 (1976) 6

Vermont Yankee Nuclear Power Corp. v. NRDC,

435 U.S. 519 (1978) 27

Yakus v. United States, 321 U.S. 414 (1944) ........... 21, 22, 26

Constitution, statutes and regulations:

U.S. Const. Art. I 1

Administrative Procedure Act:

5 U.S.C. 551(13) 36

5 US.C. 701(b)(2) 36

5 U.S.C. 706(2) 37

VII

Air Pollution Control Act of 1955, ch. 360, 69

Stat. 322 3

Air Quality Act of 1967, Pub. L. No. 90-148, § 108(c),

81 Stat. 492-494

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

99 — 42 U.S.C. 7401-7515 (1994 & Supp. III

§ 107(d), 42 U.S.C. 7407(d) (1982) 7

§ 107(d), 42 U.S.C. 240 ld) 42, 45, 46

§ 107(d)(1), 42 U.S.C. 7407(4\(1) 5, 40, 48

$ 107(d)(1)(A), 42 U.S.C. T40 (dN A "59

§ 107(d)(1(C), 42 U.S.C. 7407(4)(1\(C) 48

§ 107(d\(3), 42 U.S.C. 7407(4\(3) 47-48

§ 107(d)(4), 42 U.S.C. 7404(4)(4) 48

§ 107(d)(4)(A), 42 U.S.C. 7407(4).4)(A) 48

§§ 108-109, 42 U.S.C. 7408-7409 3

§ 108, 42 U.S.C. 7408 5

§ 108(a), 42 U.S.C. 7408(a) 39

§ 108(a)(1), 42 U.S.C. 7408(a)(1) 4

§ 108(a)(1)(A)-(B), 42 U.S.C. 7408(a)(1)(A)-(B) ceccccoeossesee. 23

§ 108(a)(2), 42 U.S.C. 7408(a)(2) 4, 23

§ 108(a)(2)(A)-(B), 42 U.S.C. 7408(a)(2A)-(B) ........... 23

#1080, 1 USC. 7408(b) 28

| 42 U.S.C. 7409 2

5 109(a)(1), 42 U.S.C. 7409(a)(1) — 1

§ 109(b)(1), 42 U.S.C. 7409%b)(1) 4, 23

§ 109(b)(1)-(2), 42 U.S.C. 7409(b)(1)-(2) *

510900) 2), 42 U.S.C. 74090b)(2) 4.5

§ 109(d), 42 U.S.C. 74094) 39

§ 109(d)(1), 42 U.S.C. 7409(4)(1) 5, 45

5 109(d)(2), 42 U.S.C. 7409(4)(2) 23

5 10 (dh )( B), 42 U.S.C. 740 (d 2) B) 4

§ 110, 42 U.S.C. 7410 3,6

§ 110(a), 42 U.S.C. 7410(a)

VIII

Statutes and regulations—Continued: Page

§ 110(a), 42 U.S.C. 7410(a)(1) 6

§ 110(c), 42 U.S.C. 7410(c) 6

§ 110(k), 42 U.S.C. 7410(k) 40

§§ 171-178, 42 U.S.C. 7501-7508 (1982) 6

§§ 171-179, 42 U.S.C. 7501-7509a (1994 &

Supp. III 1997) 7

§§ 171-193, 42 U.S.C. 7501-7515 (1994 &

Supp. IIT 1997) 6

§ 172, 42 U.S.C. 7502 16, 42

§§ 172(a) and (e), 42 U.S.C. 7502(a) and (e)

(1982) 6

§ 172(a), 42 U.S.C. 7500) . 5, 7, 8, 21, 40, 43, 45, 46

§ 172(a)(1), 42 U.S.C. 7502(a)(1) 45

§ 172(a)(1)(A), 42 U.S.C. 7502(a)(1)(A) 7, 21, 45

§ 172(a)(1)(C), 42 U.S.C. 7502(a)(1)(C) 8, 46

§ 172(a)(2), 42 U.S.C. 7502(a)(2) 45, 49

§ 172(a)(2)(A), 42 U.S.C. 7502(a)(2)(A) 7

§ 172(a)(2\(C), 42 U.S.C. 7502 ) C) 7

§ 172(a)(2)(D), 42 U.S.C. 7502(a)(2)(D) .... 8, 46

§ 172(b), 42 U.S.C. 7502(b) 40

§ 172(c), 42 U.S.C. 7502(c) 6, 40

§ 181, 42 U.S.C. 7511 : 16, 42

§ 181-185B, 42 U.S.C. 7511-7511f (1994 & Supp. III

1997) 7

§§ 181-191, 42 U.S.C. 7511-7514a (1994 & Supp. III

1997) ... 7

§ 181(a), 42 U.S.C. 75110) 16, 20, 35, 42, 46, 47, 48

§ 181(a)(1), 42 U.S.C. 7511(a)(1) passim

§ 181(a)(5), 42 U.S.C. 7511 (a)(5) 49

§ 181(b), 42 U.S.C. 7511(b) 47, 48

§§ 182-187, 42 U.S.C. 7512-7512a (1994 & Supp. III

1997) 7

§§ 188-189, 42 U.S.C. 7513-7513b 7

. NO LE A

Statutes and regulations—Continued: Page

§§ 191-192, 42 U.S.C. 7514-7514a 7

§ 307(b)(1), 42 U.S.C. 7607 h) 24, 34, 35, 36, 39, 50

§ 307(d), 42 U.S.C. 7607(d) 23

§ 307(d)(2)-(6), 42 U.S.C. 7607(d)(2)-(6) 32

§ 307(d)(3), 42 U.S.C. 7607(d)(3) 5, 24

§ 307(d)(6), 42 U.S.C. 7607(d)(6) 34, 37

§ 307(d)(6)(A), 42 U.S.C. 7607(d)(6)(A) 24

§ 307(d)(6)(b), 42 U.S.C. 7607(d)(6)(B) 15, 24

§ 307(d)(7)(B), 42 U.S.C. 7607(d)(7)(B) 35

§ 307(d)(9), 42 U.S.C. T607T(A)(Q) . 23, 24, 27, 30, 37

§ 1, 77 Stat. 395 3

Clean Air Act of 1963, Pub. L. No. 88-206, 77 Stat.

392 3

Clean Air Act Amendments of 1970, Pub. L. No.

91-604, 84 Stat. 1676 3

§ 107(a), 84 Stat. 1679-1683 3

Clean Air Act Amendments of 1977, Pub. L. No. 95-

95, 91 Stat. 685 3

Clean Air Act Amendments of 1990, Pub. L. No.

101-549, 104 Stat. 2399 3,6

Pub. L. No. 105-178, 112 Stat. 107:

§ 6101(b), 112 Stat. 463 40

§ 6102(c), 112 Stat. 464 40

§ 6103(a)-(b), 112 Stat. 465 40

42 U.S.C. 1857¢-5(a)(2)(A)()(1979) .... 6

40 C. F. R.:

Section 50.4(a)-(b) 49

Section 50.8(a)(1)-(2) 49

Section 50.9 (1990) 45

Section 50.9(b) 15, 39

Section 50.10 47

Pt. 50 App. I 47

Miscellaneous:

50 Fed. Reg. 25,532 (1985) ... 5

52 Fed. Reg. 24,634-24,635 (1987) 5

59 Fed. Reg. 38,906-38,907 (1994) 5

Miscellaneous—Continued: Page Miscellaneous—Continued: Page

61 Fed. (1996): p. 38, 864 14

pp. 65,641-65,643 9 pp. 38,864-38,865 14

p. 65,642 32 pp. 38,864-38,868 33

p. 65,644 10 p. 38,865 13, 33

pp. 65,650-65,651 2 pp. 38, 867-38, 868 14

pp. 65,71 9-65, 720 a 11 p. 38,868 14

1 — on 1 p. 8 fg —

p. 65,725-65,726 1 14 p. 38,878

p. 65,727 33 p. 38,883 —

p- = — 0 — pp. 38, 884-38, 885 15, 17, 35, 36

p. 65,730 — , H.R. Rep. No. 294, 95th Cong., Ist Sess

62 Fed Re (1997): P * ng * st . (1977) seeeeeereseeeeeees 24

— Reg. : 0 H.R. Rep. No. 490, 101st Cong., 2d Sess. Pt. 1 (1990) . 47, 49

p. — ss : Modern Epidemiology (K.J. Rothman & S. Greenland

l — . — ( at x -- 3 1998) 9

— a : , Rep. No. 1196, 91st Cong., 2d Sess. (1970)

pp. 38,656-38,657 : 31 ) 8. Rep. No. 228, 101st Cong. Ist Sons. U e

p. 2 — om a wae 1 Staff of the Senate Comm. on Pub. Works, 93d Cong.,

p. es “ 3 b 2d Sess., A Legislative History of the Clean Air Act

4 — eee eee eee ö Amendments of 1970 (Comm. Print 1974) 24-25

p. 38,669 . 10

p. 38,675-88,676 ... 10, 11, 32

pp. 38,675-38,677 . 7 32

p. 38,676 8 10, 33

pp. 38,676-38,677 .... e. ,

p. 38,677 11

p. 38,683 11

p. 38,688 —.dP•———.—.—.—.—..—.—.—. 29

p. 38,856 2

p. 38,858 1

p. 38,859 11, 12, 31

p. 38,860 12

p. 38,861 12

pp. 38,861-38,873 13

p. 38,862 . 12

p. 38,863 LAAT 12, 13, 33

pp. 38,863-38,864 i 13, 14

pp. 38,863-38,868 .. 14

In the Supreme Court of the United States

No. 99-1257

CAROL M. BROWNER, ADMINISTRATOR OF

THE ENVIRONMENTAL PROTECTION AGENCY,

ET AL., PETITIONERS

AMERICAN TRUCKING ASSOCIATIONS, INC., ET AL.

ON A WRIT OF CERTIORARI TO

THE UNITED STATES COURT OF APPEALS

FOR THE DISTRICT OF COLUMBIA CIRCUIT

BRIEF FOR THE PETITIONERS

OPINIONS BELOW

The opinion of the court of appeals (Pet. App. la-69a) is

reported at 175 F.3d 1027. The opinion on petitions for

rehearing and dissenting statements on denial of rehearing

en banc (Pet. App. 70a-101a) are reported at 195 F.3d 4.

JURISDICTION

The decision of the court of appeals was entered on May

14, 1999. Petitions for rehearing were granted in part and

denied in part on October 29, 1999. The petition for a writ of

certiorari was filed on January 27, 2000, and was granted on

May 22, 2000. The jurisdiction of this Court is invoked under

on 28 U.S.C. 1254(1).

CONSTITUTIONAL, STATUTORY, AND REGULATORY

PROVISIONS INVOLVED

Article I of the United States Constitution states in

pertinent part as follows:

All legislative Powers herein granted shall be vested in

a Congress of the United States.

(1)

The relevant sections of the Clean Air Act, 42 U.S.C. 7401

et seq., are set forth in the petition appendix at Pet. App.

105a-126a. The EPA rules at issue in this case are set forth

in the petition appendix at Pet. App. 102a-104a.

STATEMENT

Section 109 of the Clean Air Act (CAA), 42 U.S.C. 7409,

requires the Environmental Protection Agency (EPA) to

establish and periodically revise, based on the latest

scientific knowledge, primary National Ambient Air Quality

Standards (NAAQS) “requisite to protect” public health

with “an adequate margin of safety,” and secondary NAAQS

“requisite to protect” other public interests. On July 18,

1997, EPA issued final rules revising the NAAQS for two

pollutants: particulate matter (PM) and ozone.’ EPA

decided to revise the PM and ozone standards because new

scientific evidence showed that the standards then in effect

were not adequately protecting millions of Americans from

adverse health effects. For example, a quantitative risk

assessment indicated that PM concentrations below the

standards EPA established in 1987 may annually subject

people in two urban areas alone, representing about five

million people, to hundreds of early deaths, thousands of

hospital admissions for respiratory illness, and tens of

thousands of incidents of respiratory symptoms in children.

See 61 Fed. Reg. 65,638, 65,650-65,651 (1996).

On petitions for review, the court of appeals held that

Section 109, as interpreted by EPA in setting the revised

PM and ozone standards, effected an unconstitutional dele-

gation of legislative authority. The court remanded both

rules for EPA to articulate an “intelligible principle” for

determining the degree of public health protection to be

afforded by the NAAQS. In addition, even though EPA had

See NAAQS for Particulate Matter, 62 Fed. Reg. 38,652 (1997);

NAAQS for Ozone, 62 Fed. Reg. 38,856 (1997). Copies of the Federal

taken no final agency action to implement the revised ozone

NAAQS, the court issued an opinion, later modified,

interpreting the scope of EPA’s implementation authority.

I. THE CLEAN AIR ACT’S NAAQS PROVISIONS

The Clean Air Act sets up a comprehensive and extra-

ordinarily detailed program for control of air pollution

through a system of shared federal and state responsibility.’

The NAAQS are a central feature of that program. Sections

108 and 109 of the Act require EPA to establish, review, and

revise nationally applicable standards for a small class of

common air pollutants. 42 U.S.C. 7408-7409. The NAAQS

establish permissible concentrations of those pollutants in

the “ambient,” or outside, air. Section 110 of the Act then

calls on the States to impose controls on individual sources of

air pollution as necessary to attain and maintain the

NAAQS. 42 U.S.C. 7410; see Train v. NRDC, 421 U.S. 60,

78-79 (1975); Lead Indus. Ass’n v. EPA, 647 F.2d 1130, 1137

(D.C. Cir.), cert. denied, 449 U.S. 1042 (1980).

A. Air Quality Criteria And Standards

The NAAQS-setting process begins with identification of

air pollutants that are emitted from “numerous or diverse”

2 Congress first addressed the problem of air pollution through the

Air Pollution Control Act of 1955, ch. 360, 69 Stat. 322, which authorized

the Secretary of Health, Education, and Welfare (HEW) to conduct re-

search activities. Congress later expanded HEW’s authority to include,

among other things, compiling and publishing air quality criteria based on

scientific studies, Clean Air Act of 1963, Pub. L. No. 88-206, §1, 77 Stat.

392, 395. Congress later directed States to develop regionally based

ambient air quality standards and provided mechanisms for enforcement,

Air Quality Act of 1967, Pub. L. No. 90-148, § 108(c), 81 Stat. 492-494.

Congress substantially revised that program through the Clean Air Act

Amendments of 1970, Pub. L. No. 91-604, 84 Stat. 1679, which provided for

national ambient air quality standards and for state implementation. See

§ 107(a), 84 Stat. 1679-1683. Congress continued to build on that program

through the Clean Air Act Amendments of 1977, Pub. L. No. 95-95, 91

Stat. 685, and the Clean Air Act Amendments of 1990, Pub. L. No. 101-

549, 104 Stat. 2399. See text at p. 6, infra, and note 5, infra.

sources and that “may reasonably be anticipated to endanger

public health or welfare.” 42 U.S.C. 7408(a)(1). EPA has

identified six such pollutants, commonly referred to as “cri-

teria” pollutants: sulfur oxides; nitrogen oxides; carbon mon-

oxide; lead; ozone; and particulate matter.

EPA must develop “air quality criteria” reflecting the

“latest scientific knowledge” on “all identifiable effects on

public health or welfare” that may result from each criteria

pollutant’s presence in the ambient air. 42 U.S.C. 7408(a)(2).

EPA generally records the scientific assessments constitut-

ing air quality criteria in a “Criteria Document,” which pro-

vides a rigorous analysis of all pertinent scientific informa-

tion. EPA also develops a “Staff Paper” to “bridge the gap”

between the scientific review and the judgments the Admin-

istrator must make to set standards. See NRDC v. EPA,

902 F.2d 962, 967 (1990), opinion vacated in part, 921 F.2d

326 (D.C. Cir.), cert. denied, 498 U.S. 1082 (1991). Both docu-

ments undergo public notice and comment, as well as exten-

sive scientific peer-review by the Clean Air Scientific Advi-

sory Committee (CASAC), an independent committee

established under the Act to advise the EPA Administrator

on air quality criteria and NAAQS. 42 U.S.C. 7409(d)(2)(B);

see 62 Fed. Reg. 38,654 (1997).

Relying on the “air quality criteria,” EPA promulgates

“primary” and “secondary” NAAQS to protect against the

adverse health and welfare effects of each criteria pollutant.

42 U.S.C. 7409(a)(1) and (b)(1)-(2). EPA must set “primary”

standards at levels that, “in the judgment of the Administra-

tor,” are “requisite to protect the public health” with “an

adequate margin of safety.” 42 U.S.C. 7409(b)(1). EPA must

set “secondary” standards at levels that are “requisite to

protect the public welfare” from any “known or anticipated

adverse effects.” 42 U.S.C. 7409(b)(2).

We have provided a set of the Criteria Documents and Staff Papers

for PM and ozone to the Clerk of the Court.

To ensure that standards keep pace with advances in

scientific knowledge, EPA must review the air quality

criteria and standards every five years and revise them as

“appropriate in accordance with [Sections 108 and 109(b)].”

42 U.S.C. 7409(d)(1). When setting or revising NAAQS,

EPA must consider and explain any significant departure

from CASAC’s recommendations. 42 U.S.C. 7607(d)(3).

Drawing on legislative guidance, EPA has developed

decisional criteria to ensure consistency among its NAAQS

decisions. EPA considers, among other public health factors,

the nature and severity of health effects, the types of health

evidence, the kind and degree of uncertainties involved, and

the size and nature of the sensitive populations at risk. See,

e.g., 97-1440 C.A. App. (PM App.) 1908. The court of appeals

approved EPA's use of those factors 20 years ago, Lead

Indus., 647 F.2d at 1161, and EPA has since employed them

in numerous NAAQS rulemakings.‘ The court reaffirmed its

approval of EPA’s use of those factors in this case. Pet. App.

5a, 6a-7a.

B. Implementation Of Air Quality Standards

The CAA sets out a detailed process, resting on principles

of federal-state cooperation, to ensure that the air through-

out the Nation “attains” the NAAQS. Within three years of

promulgating a new or revised NAAQS, EPA must “desig-

nate” areas of the country as either “attainment” (i.e., the

area meets that NAAQS), “nonattainment” (i.e., the area

fails to meet that NAAQS), or “unclassifiable” (7.e., adequate

information is not available). 42 U.S.C. 7407(d)(1). Follow-

ing designation, EPA must establish the date by which

nonattainment areas shall attain that NAAQS (i. e., the area’s

attainment date). See 42 U.S.C. 7502(a). The CAA provides

for each State to develop, for EPA’s approval, a state imple-

4 See, e. g., 59 Fed. Reg. 38,906-38,907 (1994) (carbon monoxide

NAAQS); 52 Fed. Reg. 24,634-24,635 (1987) (PM NAAQS); 50 Fed. Reg.

25,582 (1985) (nitrogen dioxide NAAQS).

mentation plan (SIP) that sets forth pollution control mea-

sures necessary to attain all NAAQS by the applicable

attainment dates. See 42 U.S.C. 7410(a), 7502(c). See

generally Union Elec. Co. v. EPA, 427 U.S. 246 (1976);

Train, supra. If a State fails to develop an adequate SIP,

then EPA must promulgate measures to attain the NAAQS

in the form of a federal implementation plan (FIP). 42

U.S.C. 7410(c).

Congress laid the foundation for the CAA’s current regu-

latory scheme through the Clean Air Act Amendments of

1970 and the Clean Air Act Amendments of 1977. See note

2, supra.’ Congress built further on that foundation through

the Clean Air Act Amendments of 1990, Pub. L. No. 101-549,

104 Stat. 2399, which address, among other things, the

continuing problem of NAAQS nonattainment. Congress

retained with limited modifications the basic planning obliga-

tions in Section 110 for States to implement all NAAQS,

including “any revision thereof,” in all areas of the Nation,

regardless of their designation status. 42 U.S.C. 7410(a)(1).

Congress, however, adjusted the attainment obligations for

the NAAQS then in existence and revised the attainment

obligations that would result if EPA promulgated new or

revised NAAQS. As a consequence, the 1990 Amendments

contain a complicated set of new implementation obligations,

set out in the CAA’s Title I, Part D, for nonattainment areas.

See 42 U.S.C. 7501-7515 (1994 & Supp. III 1997).

The Clean Air Amendments of 1970 introduced the NAAQS concept

and required States to attain each NAAQS “as expeditiously as practica-

ble but * * * in no case later than three years” after EPA approves a

SIP. 42 U.S.C. 1857¢-5(a)(2)(A)(i) (1970). The Clean Air Act Amend-

ments of 1977 added a new outside attainment date (1982, or 1987 if

extended, 42 U.S.C. 7502(a) and (c) (1982)), and introduced the concept of

designating areas “nonattainment” for each NAAQS. 42 U.S.C. 7407(d)

(1982). The 1977 Amendments also introduced a new “Part D,” which

contained additional attainment provisions for all NAAQS that apply to all

nonattainment areas. See 42 U.S.C. 7501-7508 (1982) (Pt. D, Tit. D.

First, Congress modified the general nonattainment pro-

visions that it had previously set out in Part D, see note 5,

supra, and placed them in a new subpart, titled “Subpart 1

—Nonattainment Areas in General.” 42 U.S.C. 7501-7509a

(1994 & Supp. III 1997). Section 172(a) of that Subpart in-

cludes a new scheme for EPA to classify and establish at-

tainment dates for nonattainment areas, based upon various

factors, including the severity of the area’s pollution prob-

lem. 42 U.S.C. 7502(a).° That scheme applies to all non-

attainment areas “with respect to any [NAAQS] (or any

revised standard, including a revision of any standard in

effect on November 15, 1990).” 42 U.S.C. 7502(a)(1)(A).

Second, Congress created a series of new subparts in Part

D, which address nonattainment of each of the then-existing

NAAQS. See 42 U.S.C. 7511-7514a (1994 & Supp. III 1997)

(Subpts. 2-5, Pt. D, Tit. I). Subpart 2 contains specific

implementation provisions for the ozone NAAQS, which

apply in addition to the general implementation provisions in

Subpart 1. See 42 U.S.C. 7511-7511f (1994 & Supp. III 1997)

(“Subpart 2—Additional Provisions for Ozone Nonattain-

ment Areas“) Those provisions address the continued

nonattainment, as of 1990, of the primary ozone NAAQS

then in existence (i.e., the “one-hour” ozone standard). Sec-

tion 181(a)(1) of that Subpart sets out specific classifications

and attainment dates that apply “by operation of law” for

areas that, prior to the 1990 Amendments, were designated

6 The dates must be set so that attainment is achieved as “as expedi-

tiously as practicable,” with outside dates that may range up to 10 years

from the date an area is designated nonattainment, with two one-year

extensions possible. 42 U.S.C. 7502(a)(2)(A) and (C).

7 Subparts 3-5 contain additional provisions that address the con-

tinued nonattainment of the other existing standards. 42 U.S.C. 7512-

7512a (1994 & Supp. III 1997); 42 U.S.C. 7513-7513b, 7514-7514a.

nonattainment under the one-hour ozone standard. 42

U.S.C. 7511(a\(1).°

Third, Congress reconciled EPA’s general authority

under Section 172(a) of Subpart 1 to classify and establish

attainment dates for nonattainment areas with the attain-

ment schedule in Section 181(a)(1) of Subpart 2 (and in other

Subparts of Part D). Congress provided that EPA’s author-

ity in Section 172(a) shall not apply to “nonattainment areas

for which classifications [or “attainment dates”) are specifi-

cally provided under other provisions of [Part D].“ 42 U.S.C.

7502(a)(1)(C) and (a)(2)(D). Thus, to the extent that Section

181(a)(1) specifically provides classifications and attainment

dates for areas designated nonattainment for the one-hour

ozone standard, EPA may not invoke Section 172(a) to

establish classifications and attainment dates for that ozone

NAAQS.

II. THE PARTICULATE MATTER AND OZONE RULE-

MAKING PROCEEDINGS

On July 18, 1997, EPA promulgated revised primary and

secondary air quality standards for PM and ozone. In each

rulemaking, the Criteria Documents and Staff Papers

underwent several rounds of review by CASAC, public

comment, and revision by EPA. Ultimately, CASAC

notified EPA that the PM and ozone Criteria Documents

provided an adequate scientific basis for regulatory

decisions. PM App. 3151; 97-1441 C.A. App. (Ozone App.)

235. CASAC also notified EPA that the PM and ozone Staff

Papers, which among other things identified ranges of

8 Table 1 of Section 181(a)(1) establishes specific classifications for

nonattainment areas under the one-hour ozone standard based upon the

areas “design value,” which refers to the measurement methodology then

in use. See note 29, infra. Table 1 also sets a corresponding attainment

date for each classification, expressed as either 3, 6, 9, 15, or 20 years

“after November 15, 1990,” when the 1990 Amendments were enacted. 42

US.C. 7511(a)(1).

potential standards for the Administrator’s consideration,

were likewise scientifically adequate. PM App. 3162; Ozone

App. 236-238. As required by Section 109, EPA then set

new PM and ozone standards based on the revised air

quality criteria. EPA provided exhaustive explanations of

the basis for the two decisions, which we briefly summarize

below.

A. The Particulate Matter Rule

Particulate matter encompasses a broad class of chemi-

cally and physically diverse liquid and solid particles. 62

Fed. Reg. at 38,653. Scientists generally distinguish be-

tween two categories of PM—fine and coarse. Both were en-

compassed by the “PM,,” standards that EPA set in 1987.“

EPA revised the PM standards based on new scientific

studies that had emerged since EPA’s last PM review,

including an extensive body of epidemiological studies on

exposure to PM pollution.“ More than 60 such studies

showed statistically significant positive associations between

exposure to PM air pollution and serious adverse health

effects, including premature death and illness severe enough

to require hospital admission. 61 Fed. Reg. at 65,641-65,643;

PM App. 1375-1778, 1801-1845 (Criteria Document). The

same evidence identified several large “sensitive” popula-

9 Generally, fine particles are by-products of combustion or the

reaction and transformation of gases. PM App. 519, 1786. Coarse parti-

cles generally are the result of abrasion of material into smaller pieces,

which are then suspended in the air by wind or human activity. Id. at 519,

1787. PM,, denotes particulate matter up to about 10 micrometers (um) in

diameter, which is the fraction of PM that can be inhaled into the human

lungs. 62 Fed. Reg. at 38,654 n.1, 38,666-38,667. PM. denotes particles up

to about 2.5 pm in diameter. Id. at 38,654 n.5.

10 Epidemiological studies examine patterns of disease in real-world

human populations. Epidemiologists look for statistical associations that

may reflect cause-and-effect relationships, using the concept of statistical

significance to separate those associations from results that may be the

product of chance. See Modern Epidemiology 184 (KJ. Rothman & S.

Greenland eds., 2d ed. 1998).

tions that may experience health effects at lower PM con-

centrations, or more severely, than the general public. 61

Fed. Reg. at 65,644. Those populations included the elderly,

children, and people with cardiovascular and respiratory

disease, including asthma. Ibid.; PM App. 1991-1993.

The scientific studies indicated that those very serious

health effects were “attributable to PM at levels below the

current NAAQS.” PM App. 1870. The Administrator con-

cluded, based on the nature of the health effects and the

huge size of the affected populations, 62 Fed. Reg. at 38,657,

that the studies provided “strong evidence that the current

PM,, standards do not adequately protect public health, and

that revision of the standards is not only appropriate, but

necessary,” id. at 38,665.

The Administrator decided she could best protect against

the health risk posed by PM by adopting two sets of stan-

dards: (1) PM,; NAAQS to control fine particles, which were

likely responsible for those health effects associated with PM

concentrations at or below the 1987 NAAQS; and (2) PM,

NAAQS to provide continued control of inhalable coarse

particles. 62 Fed. Reg. at 38,665-38,668. The Administrator

selected the annual PM,, NAAQS as the “generally control-

ling” standard to reduce both long-term and peak PM,, con-

centrations and adopted the 24-hour PM. NAAQS only to

address unusual circumstances. Id. at 38,669.

To select the levels requisite to protect public health, with

an adequate margin of safety, the Administrator relied

chiefly on epidemiological studies that employed direct mea-

sures of fine particles, such as PM,;. 62 Fed. Reg. at 38,675-

38,676 & n.41. “(Placing greatest weight on those studies

that were clearly statistically significant,” the Administrator

concluded that an annual PM,, standard of 15 micrograms

per cubic meter of air (yg/m*) “will provide an adequate

margin of safety against the effects observed in these

epidemiological studies.” Jd. at 38,676. That level is just

below the range of 15.7 to 21 g/ m' that encompasses the

annual mean PM,, levels in locations where epidemiological

studies had shown statistically significant positive associa-

tions between fine particles and adverse health effects.

Ibid.; PM App. 3506-3521. The Administrator acknowledged

that “the possibility of effects at lower annual concentrations

cannot be excluded,” but she noted that the evidence

supporting that possibility—which did not rise to the level of

statistical significance—is “highly uncertain,” and therefore

did not warrant establishment of a lower annual standard.

62 Fed. Reg. at 38,675-38,676; PM App. 3506-3521."

B. The Ozone Rule

Ground-level ozone is a ubiquitous pollutant formed in the

air from the interaction in sunlight of nitrogen oxides and

volatile organic compounds emitted from many sources. It is

the principal component of smog and a powerful lung

irritant. See 62 Fed. Reg. at 38,858.”

EPA’s review of the latest scientific knowledge on ozone

disclosed a large body of new research demonstrating asso-

ciations between adverse health effects and exposure to

ozone over longer periods, at more moderate levels of exer-

tion, and at lower concentrations than had been shown by

the studies available in 1979, when EPA had promulgated an

ozone standard of 0.12 parts per million (ppm) averaged over

one hour (the one-hour standard). 62 Fed. Reg. at 38,859; 61

Fed. Reg. at 65,719-65,720. Some of those new studies

showed health effects associated with prolonged (six to eight

hours) exposure to ozone levels as low as 0.08 ppm. 62 Fed.

11 EPA adopted a 24-hour PM., NAAQS of 65 g/m to “supplement”

the protection afforded by the annual PM,, standard. 62 Fed. Reg. at

38,677. The Administrator also determined that secondary PM,, stan-

dards identical to the primary PM,, standards were appropriate to protect

public welfare from, among other things, adverse effects on visibility. Id.

at 38,683.

12 The ozone NAAQS regulates harmful ground-level or “tropospheric”

ozone, and not stratospheric ozone, which “provides a protective shield

from excess ultraviolet radiation.” 62 Fed. Reg. at 38,858.

Reg. at 38,859. The studies also showed that, in comparison

to the general population, active children and workers who

regularly engage in outdoor activities are at greater risk of

experiencing adverse health effects from exposure to ozone.

Ibid. In addition, people with pre-existing respiratory

disease are more susceptible than others to the effects of

ozone. Ibid. See generally Ozone App. 1460-1648, 1740-1780,

3770-3786, 3875-3881 (Criteria Document).

The scientific evidence convinced the Administrator that

she should revise both the averaging time and the con-

centration level of the 1979 one-hour ozone standard. 62

Fed. Reg. at 38,863. She determined, and CASAC con-

curred, that an eight-hour standard was more consistent

than a one-hour standard with the kind of prolonged expo-

sures at which the scientific evidence showed children and

others in at-risk populations were experiencing health

effects of concern. Id. at 38,861. In addition, EPA’s quan-

titative exposure and risk assessments showed that an eight-

hour standard would provide significantly greater nation-

wide uniformity in health protection than a one-hour

standard. Id. at 38,862.

To select a concentration level for the eight-hour averag-

ing period, EPA employed a weight-of-evidence approach.

Using, with CASAC’s concurrence, guidelines of the Ameri-

can Thoracic Society, EPA considered the medical signifi-

cance, or “adversity,” of ozone-related health effects, which

can vary widely. 62 Fed. Reg. at 38,860.“ EPA also

considered the public health implications of its conclusions

regarding effects on individuals. For that purpose, EPA

prepared quantitative exposure and risk assessments that

used (among other information) data from human clinical

13 For example, effects that may be mere nuisances to many healthy

people may have serious consequences for asthmatics. EPA and CASAC

also recognized that an effect that may be medically insignificant if experi-

enced only once may, with repetition, become adverse by setting the stage

for more serious illness. 61 Fed. Reg. at 65,723; Ozone App. 1881-1882.

studies to estimate, for various levels of ozone in the ambient

air, the number of people within certain sensitive population

groups likely to experience effects that would interfere with

normal activity. Jd. at 38,861-38,873.

EPA narrowed its consideration to the range of 0.07 ppm

to 0.09 ppm for an eight-hour ozone standard. The upper

bound for consideration could be no higher than 0.09 ppm

because the exposure and risk assessments showed that the

risks associated with an eight-hour standard of 0.09 ppm

were “the same or only marginally smaller” than those asso-

ciated with the 1979 one-hour standard, which EPA and

CASAC agreed provided “little, if any, margin of safety.” 62

Fed. Reg. at 38,863-38,864. The lower bound for consi-

deration also emerged from the scientific evidence, including

in particular: (1) the absence of any human clinical studies

on exposures below 0.08 ppm, id. at 38,863; and (2) quanti-

tative exposure assessments showing that a 0.07 ppm

standard would, over the course of an ozone season, limit

“exposures of concern” to “essentially zero,” ibid.“

The Administrator explained why she found significant

differences in the character of the available scientific evi-

dence regarding ozone exposures within the range identified.

She compared a 0.08 ppm standard to a 0.09 ppm standard on

the basis of a number of factors, including estimates of the

relative number of children that would experience adverse

health effects, the relative frequency of such effects, and

relative increases in hospital admissions. Those estimates

and estimates of occurrences of “exposures of concern”

14 With CASAC’s concurrence, EPA deemed eight-hour exposures,

during moderate exertion, to ozone concentrations of 0.08 ppm or above to

be “exposures of concern” for purposes of the quantitative exposure and

risk assessments. 62 Fed. Reg. at 38,865. In those analyses, EPA used

data from human clinical studies, which necessarily related to only the

mildest health effects. A single “exposure of concern” would not

necessarily cause adverse effects, but is an indicator of the public health

impacts of more serious effects.

under a standard of 0.09 ppm counseled against use of that

concentration. 62 Fed. Reg. at 38,867-38,868; see note 14,

supra. For example, EPA estimated that a 0.09 ppm stan-

dard would allow more than three times as many children to

experience exposures of concern than would a standard of

0.08 ppm. 62 Fed. Reg. at 38,868.

The Administrator also explained why she concluded that

a standard set below 0.08 ppm would be more stringent than

requisite to protect against adverse effects of public health

significance. See 62 Fed. Reg. at 38,863-38,868. With

CASAC’s concurrence, EPA had reasonably assumed, for

purposes of the quantitative risk assessment, that there is no

“effects threshold” for the categories of health effects mea-

sured in human clinical studies—lung function decreases and

respiratory symptoms. EPA therefore assumed that those

effects may occur at ozone levels below 0.08 ppm. See 61

Fed. Reg. at 65,725-65,726. As to those effects, the record

showed that average responses caused by exposures even at

0.08 ppm were “typically small or mild in nature.” 62 Fed.

Reg. at 38,864. The Administrator recognized that repeated

exposures at the 0.08 ppm level could potentially produce

adverse effects for some unusually sensitive individuals,

ibid., but the record indicated that the “most certain” ozone-

related effects at and below that level, even when adverse,

are “transient and reversible,” id. at 38,868. Moreover, the

quantitative exposure and risk assessments showed that a

standard set at 0.08 ppm would significantly reduce the

number of such exposures. See ibid. As for more serious

health effects, EPA lacked clinical data indicating the

existence of an exposure-response relationship at ozone

levels below 0.08 ppm. See id. at 38,863-38,864, 38,868;

Ozone App. 1962. Furthermore, none of the CASAC

advisors recommended setting the revised NAAQS at a level

below 0.08 ppm. 62 Fed. Reg. at 38,864-38,865, 38,868.

Accordingly, the Administrator reasonably concluded, based

on the available evidence, that an eight-hour ozone standard

of 0.08 ppm would be sufficient to protect public health with

an adequate margin of safety. Id. at 38,868-38,869."°

In addition to explaining the basis for its decisions, EPA

responded, as required by the Act, 42 U.S.C. 7607(d)(6)(B),

to all significant public comments. Various commenters had

argued that, by enacting in 1990 specific provisions

regarding implementation of the one-hour ozone standard

then in effect, e.g., 42 U.S.C. 7511(a)(1), Congress had

effectively codified that standard and precluded EPA from

revising it. In response, EPA explained that its authority to

revise the one-hour ozone standard was clear on the face of

the Act and then briefly and generally discussed how some

of the Act’s provisions would apply to implementation of a

revised ozone standard. The sole purpose of that discussion

was to respond fully to the comments arguing that the 1990

Amendments curtailed EPA’s authority to revise the ozone

standard. 62 Fed. Reg. at 38,884-38,885; see App., infra, la-

6a (reproducing the preamble discussion).

III. THE PROCEEDINGS BELOW

Numerous industry groups, a public interest group, and

several States and individuals challenged the revised PM

and ozone NAAQS. The court of appeals rejected many of

the challenges, but nevertheless remanded both final rules to

EPA with instructions “to develop a construction of the act”

that would satisfy this Court’s “nondelegation doctrine.”

Pet. App. 4a, 5a. Relying on a theory that the parties had

not extensively briefed, the court concluded that EPA’s

interpretation of Section 109 of the CAA “effects an uncon-

stitutional delegation of legislative power.” Id. at 4a.

According to the majority, EPA’s interpretation of the Act

15 EPA set a revised secondary ozone standard identical to the revised

primary standard. 62 Fed. Reg. at 38,878. In addition, EPA issued a

separate rule, 40 C.F.R. 50.9(b), respecting future enforcement of the one-

hour ozone standard, which the revised eight-hour ozone standard would

replace. See note 26, infra.

leaves it “free to pick any point between zero and a hair

below * * * London’s Killer Fog,” a notorious 1952 incident

in which air pollution may have caused approximately 4000

deaths over four days. Id. at 13a. Judge Tatel dissented

from that portion of the opinion, emphasizing that the major-

ity “ignore[d] the last half-century of Supreme Court non-

delegation jurisprudence” upholding numerous statutes con-

taining fewer guiding principles than Section 109. Id. at 59a.

In the ozone case (No. 97-1441), the court of appeals

rejected the industry petitioners’ argument that the 1990

Amendments, which established mandatory classifications

and attainment dates for the primary one-hour ozone

standard then in effect, see CAA § 181, 42 U.S.C. 7511,

precluded EPA from revising the ozone NAAQS. Pet. App.

34a-37a. That ruling resolved the issue before the court.

The court of appeals nevertheless went on to direct what

EPA may and may not do when it proceeds—in the

future—to implement the ozone NAAQS. The court ruled

that EPA cannot implement the revised ozone NAAQS

through Section 172 (42 U.S.C. 7502), but must instead

employ Section 181(a) (42 U.S.C. 7511(a)). Pet. App. 34a,

37a-44a. Because the requirements of Section 181(a) are tied

to the one-hour standard, the court’s ruling effectively

meant, as the court itself recognized, that EPA could pro-

mulgate, but could not enforce, the revised ozone NAAQS.

. at 57a.“ .

K SPA and other parties filed petitions for rehearing and

suggestions for rehearing en banc. The panel * =

hearing, in part, to modify its opinion regarding EPA’s

authority to implement the revised osone standard. —

App. 7la-72a. The panel rejected EPA’s argument that,

all, of the other chal-

16 The court of appeals resolved some, but not all, ‘

lenges to the PM and ozone rules. See Pet. App. 4a-5a. The court con

cluded that some of the issues could not be resolved “until such time as

EPA may develop a constitutional construction of the act.” Id. at 5a.

because EPA had yet to take final action implementing the

revised ozone NAAQS, the court lacked jurisdiction to con-

sider which provisions of the Act would govern implemen-

tation, including the specification of classifications and

attainment dates. Id. at 78a-80a. The court found that

EPA’s statements on that issue in the preamble accom-

panying the revised ozone standard, made in response to

industry comments challenging EPA’s authority to pro-

mulgate that standard, see 62 Fed. Reg. at 38,884-38,885,

constituted final agency action on the question of imple-

mentation that was ripe for judicial review. Pet. App. 78a-

80a.

On the merits, the panel modified its opinion to state that

“EPA can enforce a revised primary ozone NAAQS only in

conformity with Subpart 2.” Pet. App. 8la. Judge Tatel

wrote separately because he disagreed with the panel ma-

jority’s reasoning. Pet. App. 83a-89a. He found the statute

ambiguous and would have deferred to EPA’s interpreta-

tion. Id. at 84a. Judge Tatel nevertheless concurred in the

judgment because, in his view, the modified decision would

allow EPA to implement the revised ozone standard under

Subpart 1 once an area has attained the one-hour standard in

accordance with Subpart 2. Id. at 89a. As to the non-

delegation issue, the panel denied EPA’s petition for re-

hearing. It expressly rejected EPA’s view that the relevant

provisions of the Act set out intelligible principles that limit

the agency’s discretion. Id. at 72a-76a. Judge Tatel again

dissented. Id. at 89a, 97a-99a.

The court also denied EPA’s suggestion for rehearing en

bane, with five of the court’s eleven active judges voting in

favor of rehearing en banc, and four voting against it. Pet.

App. 90a-92a. Judge Silberman and Judge Tatel each wrote

statements dissenting from the denial of rehearing en banc

on the nondelegation issue. Jd. at 92a-96a, 97a-99a. Chief

Judge Edwards and Judge Garland joined in Judge Tatel’s

statement. Id. at 97a.

SUMMARY OF ARGUMENT

1. The court of appeals incorrectly concluded that

Section 109 of the CAA, as interpreted by EPA, violates the

nondelegation doctrine. Section 109’s requirement that

NAAQS must be set at a level “requisite to protect” public

health with “an adequate margin of safety” does not con-

stitute an unconstitutional grant of legislative power. Fur-

thermore, the nondelegation doctrine does not impose a con-

stitutional obligation on EPA to go beyond what Congress

has directed and announce a “determinate criterion for

drawing lines.” Pet. App. 5a-6a. The court’s novel view that

the Constitution demands such a precise criterion—and that

the agency must supply it—is fundamentally unsound.

Congress has directed EPA to establish NAAQS by refer-

ence to the CAA’s detailed requirements, which set out

intelligible principles to guide EPA’s actions. The CAA’s

directives, which are more specific than many statutory

directives that this Court has upheld, amply ensure that

Congress has not abdicated its power to make the laws. The

CAA prescribes the legal standards governing EPA's

decisions, factors that EPA must consider in making its de-

cisions under Section 109, a body of experts that EPA must

consult on those decisions, and a rigorous set of procedures

that EPA must follow. In short, the Act establishes multiple

specific restrictions that cabin EPA’s discretion in setting

NAAQS. The nondelegation doctrine does not require more.

The court of appeals’ direction that EPA must narrow the

scope of Congress’s direction is not only unprecedented, it

also is contrary to the purpose of the nondelegation doctrine.

The Court has developed that doctrine to enforce the Con-

stitution’s requirement that Congress alone shall exercise

legislative power. The court of appeals has improperly

employed the doctrine to expand the scope of its judicial

review authority beyond the limits that Congress has set

through the CAA’s statutory standards for review of agency

action. The court of appeals’ conclusion that EPA must

provide a “determinate, binding standard” for setting

NAAQS is not only inconsistent with the CAA’s recognition

that NAAQS must be set in the face of scientific uncer-

tainties, but it is also likely impracticable. An Executive

Branch agency, acting pursuant to congressional direction, is

entitled to assess the available evidence and make a rea-

soned judgment on the proper regulatory standard. Con-

trary to the court of appeals’ characterization, EPA’s inter-

pretation of its authority did not leave it free to set a

NAAQS at any point between zero and “a hair below” an air

pollution level that killed 4000 people in four days. To the

contrary, the rulemaking records reveal that EPA properly

construed and applied limitations on its discretion. It pro-

vided reasoned explanations, supported by the record evi-

dence, for why it chose the challenged PM and ozone stan-

dards in light of continuously evolving scientific knowledge.

2. The court of appeals also erred in prematurely decid-

ing the scope of EPA’s authority to implement and enforce

the revised standard. The court did so by subjecting EPA’s

preamble statements on how it may implement the revised

ozone standard to judicial review. Those preamble state-

ments do not constitute judicially reviewable agency action.

EPA made those statements to respond to comments that

the implementation scheme in Section 181(a)(1) negates

EPA’s authority to promulgate a revised ozone standard.

Once the court of appeals rejected that challenge to EPA’s

NAAQS revision authority, its task was done. It should not

have treated EPA’s preamble statements that explain the

basis for EPA’s ozone NAAQS as separate agency action

that is independently subject to judicial review.

Even if EPA’s preamble remarks about what future steps

it intends to take to implement the ozone NAAQS consti-

tuted “agency action,” they are certainly not “final” agency

action. Those statements are not the consummation of the

agency’s decisionmaking process and they do not create any

rights or obligations. They simply express EPA’s current

views on some aspects of the complicated implementation

process that EPA and the States will undertake through

future rulemakings. The CAA sets out a detailed procedure

for conducting those rulemakings. Under the statutory pro-

cess, EPA will issue final rules on specific subjects in an

orderly fashion, and each final rule will be subject to judicial

review when the rule is ripe for the court’s review.

Even if EPA’s preamble statements constituted final

agency action, they would not be ripe for review. The issue

of how to reconcile the numerous provisions governing

implementation is, at this stage, too abstract. The courts do

not have the benefit of EPA’s explanation of how and why it

has implemented a NAAQS in a particular way, which would

be available only after EPA has completed the relevant rule-

makings, including any required public notice and response

to comments, and taken final action that actually implements

the standard. The courts should not review those complex

implementation issues until EPA has had the opportunity to

work through the various implementation provisions,

reconcile any conflicts, make any policy judgments, and

apply its expertise to resolve any ambiguities in the statute.

3. Ifthe Court decides to reach the merits, it should rule

that the court of appeals’ modified decision is incorrect, even

as interpreted by Judge Tatel in his partial concurrence.

The CAA authorizes EPA to implement the revised national

ozone standard contemporaneously throughout the country,

regardless of whether an area is violating the one-hour ozone

standard. The court of appeals’ decision would inappropri-

ately force EPA to delay protecting the public from the very

health consequences that warrant a NAAQS revision in the

first place, until the area attains an air quality standard that

EPA has concluded is inadequate to protect public health.

Congress could not have intended that implausible result.

The statutory provision on which the court of appeals

primarily relied—Section 181(a) of Subpart 2—implements

only the one-hour ozone standard. It does not apply to the

revised eight-hour ozone NAAQS or otherwise curtail EPA’s

authority to implement that standard under Section 172(a)

and any other applicable provision of Subpart 1. Moreover,

because the Act requires the attainment of all NAAQS “as

expeditiously as practicable,” 42 U.S.C. 7502(a)(1)(A),

7511(a)(1), the court of appeals erred in concluding that EPA

must delay implementation of the eight-hour NAAQS in any

area until it attains the one-hour ozone standard.

ARGUMENT

I. THE COURT OF APPEALS ERRONEOUSLY A.

PLIED THE NONDELEGATION DOCTRINE

The nondelegation doctrine is “rooted in the principle of

separation of powers.” Mistretta v. United States, 488 U.S.

361, 371 (1989). “The fundamental precept of the delegation

doctrine is that the lawmaking function belongs to Congress,

U.S. Const., Art. I, § 1, and may not be conveyed to another

branch or entity.” Loving v. United States, 517 U.S. 748, 758

(1996). The nondelegation doctrine does not require, how-

ever, that Congress dictate every detail of a regulatory pro-

gram. Congress may rely on the other branches to make

rules that carry out its will. See Loving, 517 U.S. at 758:

Mistretta, 488 U.S. at 372.

This Court’s application of the nondelegation doctrine has

been “driven by a practical understanding that in our

increasingly complex society, replete with ever changing and

more technical problems, Congress simply cannot do its job

absent an ability to delegate power under broad general

directives.” Mistretta, 488 U.S. at 372. The Court has

accordingly recognized that Congress does not violate the

Constitution “merely because it legislates in broad terms,

leaving a certain degree of discretion to executive or judicial

actors.” Touby v. United States, 500 U.S. 160, 165 (1991); see

Yakus v. United States, 321 U.S. 414, 425 (1944) (Congress

may “call for the exercise of judgment, and for the formu-

lation of subsidiary administrative policy within the pre-

scribed framework”).

The Court has specifically emphasized that Congress does

not violate the nondelegation doctrine if “Congress clearly

delineates the general policy, the public agency which is to

apply it, and the boundaries of this delegated authority.”

Mistretta, 488 U.S. at 372-373 (quoting American Power &

Light Co. v. SEC, 329 U.S. 90, 105 (1946)); Skinner v. Mid-

America Pipeline Co., 490 U.S. 212, 218-219 (1989). “Only if

we could say that there is an absence of standards for the

guidance of the [agency’s] action, so that it would be impossi-

ble in a proper proceeding to ascertain whether the will of

Congress has been obeyed, would we be justified in over-

riding its choice of means for effecting its declared purpose.”

Mistretta, 488 U.S. at 379 (emphasis added) (quoting Yakus,

321 U.S. at 425-426).

A. Section 109 Of The Clean Air Act Does Not Constitute

An Unconstitutional Grant Of Legislative Power

Contrary to the court of appeals’ conclusion, Section 109

easily satisfies this Court’s “intelligible principle” standard.

This Court’s decisions leave no doubt that Section 109 does

not amount to an invalid delegation of legislative power and

that EPA can properly fulfill the responsibilities that Section

109 assigns. Section 109’s directives “are far more specific

than the sweeping statutory delegations consistently upheld

by [this] Court for more than sixty years.” Pet. App. 97a

(Tatel, J., dissenting from denial of rehearing en banc); see

also id. at 93a (Silberman, J., dissenting from denial of re-

hearing en banc); id. at 59a-60a (Tatel, J., dissenting) (collect-

ing cases).

The starting point for nondelegation analysis is the CAA’s

language, which must be read in context with due regard to

the Act’s purpose and history. See American Power &

Light, 329 U.S. at 104. A perusal of this comprehensive

legislation, which Congress has repeatedly amended in light

of new knowledge and developments (see note 2, supra), re-

veals that Congress has exercised its lawmaking function

with exacting care. The Act, which now occupies more than

280 pages in the United States Code, is extraordinarily

detailed and prescriptive. As the Act has evolved, Congress

has consistently recognized the need to rely on an Executive

Branch agency’s scientific resources and expertise in execut-

ing the legislative purposes. At the same time, Congress has

carefully channeled EPA’s discretion through increasingly

detailed substantive and procedural requirements.

Section 109(b)(1) of the Act requires that primary

NAAQS be set at levels “requisite to protect the public

health” with an “adequate margin of safety” and that secon-

dary standards be set at levels “requisite to protect the

public welfare.“ 42 U.S.C. 7409(b)(1). To warrant the

setting of a NAAQS, a pollutant must “reasonably be anti-

cipated to endanger public health or welfare” and be emitted

from “numerous or diverse * * * sources.” 42 U.S.C.

7408(a)(1)(A)-(B). Each standard must be based on “air

quality criteria” that reflect “the latest scientific knowl-

edge,” 42 U.S.C. 7408(a)(2), including information on vari-

able factors” that “may alter the effects on public health,” as

well as interactions with other pollutants “to produce an

adverse effect on public health or welfare.” 42 U.S.C.

7408(a)(2)(A)-(B). Further, the Act establishes and pre-

scribes the composition of CASAC (see p. 4, supra) and

requires EPA to consider, and explain any significant de-

parture from, CASAC’s advice on revision of the air quality

criteria and standards. 42 U.S.C. 7409(d)(2), 7607(d)\9).”

Section 307(d) of the Act, 42 U.S.C. 7607(d), which sets out

the procedures for rulemaking and judicial review, further

17 See Mistretta, 488 U.S. at 376 n.10 (Congress explicit requirement

that the Commission consult with authorities in the field,” among other

things, gives content to the statutory mandate.).

ensures that EPA adheres to a “disciplined decisionmaking

process” in setting NAAQS. See Pet. App. 63a (Tatel, J.,

dissenting). Congress has prescribed a rulemaking process

that ensures extensive public participation. EPA must dis-

cuss the data, methodology, and major legal and policy

interpretations underlying proposed NAAQS, 42 U.S.C.

7607(d)(3); provide a reasoned explanation for its decision, 42

U.S.C. 7607(d)(6)(A); and respond to significant comments,

42 U.S.C. 7607(d)(6)(B). EPA’s rule is then subject to

judicial review. 42 U.S.C. 7607(b)(1) and (d)(9).“

The Act’s legislative history “provides additional guidance

for [EPA’s] consideration of the statutory factors” that is

relevant for assessing the constitutionality of Section 109.

Mistretta, 488 U.S. at 376 n.10. That legislative history,

which the court below failed to consider, indicates that the

health effects justifying a NAAQS must be “adverse,” Lead

Indus., 647 F.2d at 1152 (citing S. Rep. No. 1196, 91st Cong.,

2d Sess. 10 (1970) (S. Rep. 1196)), in the sense that they are

medically significant and not merely detectable, id. at 1155

n.51. To provide an “adequate margin of safety,” standards

must be “preventative or precautionary,” reflecting an

emphasis on the “predominant value of protection of public

health.” Ibid. (quoting H.R. Rep. No. 294, 95th Cong., Ist

Sess. 49 (1977) (H.R. Rep. 294)); id. at 1155 (EPA must “err

on the side of caution”). Furthermore, public health is dis-

tinct from individual health; the standards must protect

sensitive populations, such as asthmatics, id. at 1152, but not

the most sensitive individuals within those populations. See

S. Rep. 1196, at 10 (EPA must consider effects on “a repre-

sentative sample of persons comprising the sensitive group

rather than to a single person in such a group.”), in 1 Staff of

18 The availability of such review weighs strongly in favor of the

constitutionality of Section 109’s grant of agency authority. See American

Power & Light, 329 U.S. at 105 (“[pjrivate rights are protected by access

to the courts to test the application of the policy in the light of the[)

legislative declarations”); Touby, 500 U.S. at 170 (Marshall, J., concurring).

the Senate Comm. on Pub. Works, 93d Cong., 2d Sess., A

Legislative History of the Clean Air Act Amendments of

1970, at 410 (Comm. Print 1974).

In short, Congress has placed “multiple specific restric-

tions” on EPA’s discretion in setting and revising NAAQS

that satisfy the constitutional requirements of the nondele-

gation doctrine. Touby, 500 U.S. at 167. Those restrictions

are at least as rigorous as those in Towby and other non-

delegation cases, many of which in fact involved far less

prescriptive legislation. See id. at 165. The Act prescribes

the legal standard EPA is to apply, factors that EPA is to

consider, a body of experts that EPA is to consult, and pro-

cedures that EPA must follow in making its highly technical

scientific judgments about the health and welfare effects of

particular pollutants. As in American Power & Light Co.,

the Act provides “a veritable code of rules” for EPA to fol-

19 For example, in Touby, the Court held that the challenged statute,

which authorizes the Attorney General to regulate new “designer” drugs,

“meaningfully constrains” the Attorney General's discretion by requiring

her to find that action is “necessary to avoid an imminent hazard to the

public safety”; to “consider” three factors and statutorily prescribed

criteria; to publish notice in the Federal Register, and to consider com-

ments from an agency head. 500 U.S. at 166. In Mistretta, the Court held

that the statutory authorization for sentencing guidelines is “sufficiently

specific and detailed to meet constitutional requirements,” noting that

Congress specified three “goals” and four “purposes”; “prescribed the

specific tool” for regulating sentencing; directed the Commission to con-

sider seven “factors,” and prohibited it from considering other factors; and

explicitly required the Commission to consult authorities in the field of

criminal sentencing. 488 U.S. at 374-375 & 376 n.10. In Federal Energy

Administration v. Algonquin SNG, Inc., 426 U.S. 548 (1976), the Court

held the challenged statute constitutional because it established precon-

ditions to presidential action; allowed the President to act only to the

extent “necessary” to achieve the statutory objective; and articulated a

series of specific factors that he was to consider in exercising his author-

ity. Id. at 559.

low in fulfilling Congress’s will. 329 U.S. at 105; see Yakus,

321 U.S. at 426.”

B. The Court Of Appeals Improperly Employed The

Nondelegation Doctrine To Expand The Scope Of Its

Review

This Court’s nondelegation doctrine preserves the Consti-

tution’s separation of powers by ensuring that Congress

does not abdicate its power to make laws. The court of

appeals transformed that doctrine, however, into a judicial

check on executive power. The court of appeals employed

the nondelegation doctrine as an additional means, beyond

the explicit judicial review provisions of the CAA, to super-

vise the exercise of administrative discretion. See Pet. App.

14a. The court directed EPA to “develop[] determinate,

binding standards for itself” to reduce the likelihood that

EPA would “exercise the delegated authority arbitrarily”

and to “enhance the likelihood that meaningful judicial

review will prove feasible.” Ibid. That novel use of the

nondelegation doctrine departs from the doctrine’s purpose,

it has no basis in this Court’s precedents, and it trenches on

Congress’s power to specify appropriate standards for

judicial review of executive action. See id. at 93a (Silber-

man, J., dissenting from the denial of rehearing en banc).

20 Because Section 109 so plainly satisfies the nondelegation doctrine,

there is no need to consider, as some of the industry respondents have

urged, whether EPA should have read Section 109 more narrowly to avoid

a constitutional issue. This Court rejected a similar argument in

Algonquin SNG, Inc., 426 U.S. at 558-559. In that case, the Court held

that because the standards provided by the challenged statute were

“clearly sufficient to meet any delegation doctrine attack,” there was no

need to give the statute a narrow construction to avoid an alleged serious

question of unconstitutional delegation of legislative power.” Id. at 559.

So too, in this case, “the terminology” of the Act “does not come so close

to” the “boundaries limiting the scope of congressional delegation to the

executive branch” as “to raise a serious constitutional problem.” Pet. App.

98a (Silberman, J., dissenting from denial of rehearing en banc).

The court of appeals viewed the nondelegation doctrine as

requiring Congress, or agencies interpreting the intent of

Congress, to delineate a “determinate criterion for drawing

lines.” Pet. App. 6a. In the court’s view, the Constitution

requires that EPA supply a single principle that would

enable the court to conclude that EPA’s NAAQS are set at

what the court deems exactly the “right” level. See id. at

10a-lla, 73a. That approach, however, is inconsistent with

the court’s limited role in reviewing NAAQS. The CAA

makes clear that EPA’s actions in setting NAAQS are

subject to review under the arbitrary or capricious standard

of judicial review. See 42 U.S.C. 7607(d)(9). Under that

standard, the court is limited to examining whether EPA’s

action “was based on consideration of the relevant factors

and whether there has been a clear error of judgment.”

Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S.

402, 416 (1971) (Overton). “The court is not empowered to

substitute its judgment for that of the agency.” Ibid. As

Judge Silberman recognized, the court of appeals’ approach

would “implicitly assertſ] a greater role for a reviewing court

than is justified.” Pet. App. 96a. See Baltimore Gas & Elec.

Co. v. NRDC, 462 U.S. 87, 103 (1983) (“When examining this

kind of scientific determination, as opposed to simple find-

ings of fact, a reviewing court must generally be at its most

deferential.”).”

Moreover, the court of appeals’ demand for a determinate

criterion to govern EPA’s NAAQS decisions is difficult to

*! The court’s direction to EPA to develop “determinate, binding stan-

dards” to govern the agency’s NAAQS decisions (Pet. App. 14a, 73a) is

also inconsistent with this Court’s decision in American Power & Light

Co., which rejected the notion that there is “any constitutional require-

ment” obligating an agency to translate legislative standards into “formal

and detailed rules of thumb” before applying them. 329 U.S. at 106. Cf.

Vermont Yankee Nuclear Power Corp. v. NRDC, 435 U.S. 519, 543-545

(1978) (courts may not impose on agencies procedures that are not

imposed by statute).

reconcile in practice with the Act’s command that EPA set

NAAQS—and revise them, as appropriate, every five

years based on the “latest scientific knowledge.” 42 U.S.C.

7408(b). As the D.C. Circuit has recognized in the past,

Congress has directed EPA to make “predictions * * * at

the frontiers of science.” NRDC, 902 F.2d at 968 (quoting

New York v. EPA, 852 F.2d 574, 580 (D.C. Cir. 1988), cert.

denied, 489 U.S. 1065 (1989)); accord Lead Indus., 647 F. 2d

at 1147. Because “the statute is ‘precautionary’ in nature,

the evidence ‘uncertain or conflicting’ and the ‘regulations

designed to protect the public health,’” the court of appeals

has recognized that Congress did “not demand rigorous step-

by-step proof of cause and effect.” NRDC, 902 F.2d at 968

(citations omitted).

The purpose of Section 109’s requirement that NAAQS

provide an “adequate margin of safety” is to ensure “a rea-

sonable degree of protection * * * against hazards which

research has not yet identified.” Lead Indus., 647 F. 2d at

1150 (quoting S. Rep. 1196, at 10). EPA must therefore be

able to draw conclusions from “suspected, but not completely

substantiated, relationships between facts, from trends

among facts, from theoretical projections from imperfect

data, from probative preliminary data not yet certifiable as

‘fact,’ and the like.” NRDC, 902 F.2d at 968 (quoting Ethyl

Corp. v. EPA, 541 F.2d 1, 28 (D.C. Cir.) (en banc), cert.

denied, 426 U.S. 941 (1976)); H.R. Rep. 294, at 43-51, 110-112.

To hold EPA to the court’s novel demand for precision would

restrict the agency’s ability to act on a precautionary basis in

the face of scientific uncertainties, thereby potentially erod-

ing the public health protection Congress intended NAAQS

to afford.

The court of appeals’ requirement that EPA develop a

“determinate criterion for drawing lines” (Pet. App. 6a),

which EPA would presumably be required to apply in every

NAAQS proceeding (see id. at 73a), is also inconsistent with

EPA's own expert assessment of the flexibility necessary to

apply Section 109’s mandate to all the pollutants for which

EPA must develop standards. In the PM and ozone rule-

making proceedings, EPA received comments arguing that

the Act required the agency to adopt various specific ap-

proaches to decisions under Section 109, such as, for exam-

ple, first determining a “safe level” and then applying a mar-

gin of safety. 62 Fed. Reg. at 38,688, 38,883. In its response

to those comments, EPA noted that the D.C. Circuit had

specifically rejected claims that any of the approaches sug-

gested by the commenters were required by the Act and in-

stead had ruled that “[tJhis court must allow [the Adminis-

trator] the discretion to determine which approach will best

fulfill the goals of the Act.” Ibid. (quoting Lead Indus., 647

F. ad at 1161-1162).

The criteria pollutants that are subject to the NAAQS

process vary widely in relation to key factors, including their

health effects, the types of available scientific evidence, the

kind and degree of scientific uncertainties, and the size of

sensitive populations. Because of that wide variation:

[T]he most appropriate approach to establishing a

NAAQS with an adequate margin of safety may be dif-

ferent for each standard under review. Thus, no general-

ized paradigm * * * can substitute for the Administra-

tor’s careful and reasoned assessment of all relevant

health factors in reaching such a judgment.

62 Fed. Reg. at 38,688; see id. at 38,883."

2 The two pollutants at issue here illustrate this fact. In assessing the

health effects of PM and ozone, EPA determined that the most useful

scientific information currently consists primarily of epidemiological

studies in the case of PM, but currently consists primarily of human

clinical studies in the case of ozone. The PM epidemiological studies pro-

vide evidence of very serious health effects associated with ambient

pollution concentrations, but that evidence must be evaluated in light of

potentially confounding variables that cannot be directly controlled when

studying “real world” populations. The human clinical studies on ozone

provide strong evidence of specific effects triggered by controlled

At bottom, the court’s rationale for its approach—to pre-

vent arbitrary agency action and to enhance judicial review

(Pet. App. 14a)—overlooks that Congress is entitled to set

the parameters for judicial oversight of EPA’s scientific

judgments. Congress has concluded that EPA’s actions in

setting NAAQS are subject to the arbitrary or capricious

test. See 42 U.S.C. 7607(d)(9). EPA must consider the fac-

tors that the Act prescribes and provide a reasoned explana-

tion, based on scientific evidence, for its decision. When re-

viewing that decision, a court is not entitled to demand that

EPA demonstrate that the numerical standard the agency

selected was the sole possible choice. To the contrary, as

this Court explained in reviewing rates set by the Federal

Power Commission under a statute requiring rates to be

“just and reasonable”:

[Tjhere is no single cost-recovering rate, but a zone of

reasonableness: “Statutory reasonableness is an ab-

stract quality represented by an area rather than a

pinpoint. It allows a substantial spread between what is

unreasonable because too low and what is unreasonable

because too high.”

FPC v. Conway Corp., 426 U.S. 271, 278 (1976) (quoting

Montana-Dakota Util. Co. v. Northwestern Pub. Serv. Co.,

341 U.S. 246, 251 (1951)).

This Court’s decisions in Conway and similar cases do not

announce novel concepts. The D.C. Circuit has itself ac-

knowledged, when it reviewed the 1987 PM standard, that a

reviewing court should not ask if EPA has identified “the

clear and sole appropriate standard,” but rather whether

EPA has selected a standard that is reasonable in light of the

record evidence. NRDC, 902 F.2d at 972. The court of

appeals here relied on the nondelegation doctrine as its sole

pollutant concentrations, but—for ethical and other reasons—cannot be

used to measure directly very serious health effects or effects in highly

susceptible individuals.

justification for departing from that established standard of

review. Pet. App. 12a-13a. Under this Court’s precedents,

Section 109 does not violate the nondelegation doctrine. The

court of appeals improperly relied on that doctrine to depart

from traditional principles governing the scope of judicial

review of agency action.

C. EPA Has Recognized Limitations On Its Discretion To

Revise The Particulate Matter And Ozone Standards

The court of appeals’ nondelegation holding rests on the

erroneous conception that EPA interprets Section 109 to set

no limits on its discretion. The court characterized EPA as

claiming discretion so broad as to leave it free to “pick any

point between zero and a hair below * * * London’s Killer

Fog.” Pet. App. 18a. To the contrary, EPA has recognized

and applied principles that channel its discretion far more

narrowly than the court acknowledged.

The CAA’s directive that EPA must base the revised

NAAQS on “air quality criteria” reflecting the “latest

scientific knowledge” limits, at the outset, the alternatives

that EPA can consider. EPA found that a wide range of

adverse health effects were occurring at concentrations

below the pre-existing PM and ozone NAAQS, which

effectively dictated an upper bound for any revised NAAQS.

The revised PM and ozone NAAQS had to be at least as

protective as those pre-existing standards. See, e.g., 62 Fed.

Reg. at 38,656-38,657, 38,665; id. at 38,859; 61 Fed. Reg. at

65,719-65,721; pp. 10-13, supra. In each case, EPA also

identified a lower bound for consideration at the most pro-

tective levels the scientific evidence reasonably supported.

For PM, the lower bound was the lowest level at which long-

term epidemiological data indicated there might be an

“effects threshold” below which there is no risk of health

effects. See PM App. 2145, 2147. For ozone, which appears

to have no effects threshold (see note 23, infra), the lower

bound—0.07 ppm—was the level at which EPA’s exposure

assessment showed that exposures of public health concern

were “essentially zero.” 61 Fed. Reg. at 65,728, 65,730.

EPA’s review of the latest scientific knowledge on the

health effects of PM confined the agency to considering a

quite limited range of 12.5 to 20 pg/m* for the annual PM.;

standard (and 20 to 65 hg / m for the daily PM,, standard).

See 62 Fed. Reg. at 38,675-38,677; PM App. 2158 (Staff

Paper). That range is obviously far more narrow than a

range from zero to a hair below” 2,500 hg / m' (the level the

court of appeals assumed for the “Killer Fog”). Similarly,

EPA’s review of the latest scientific knowledge on the health

effects of ozone confined the agency to considering an eight-

hour ozone standard between 0.07 ppm and 0.09 ppm. See p.

13, supra. EPA had identified those ranges in its Staff

Papers, and CASAC had agreed that EPA’s identification of

those ranges had sound scientific support. See PM App.

3162; Ozone App. 238; pp. 8-9, supra.

Furthermore, although EPA may exercise discretion in

selecting a standard, EPA is constrained in doing so by the

CAA’s explicit requirement that the agency consider

relevant factors, apply them to relevant facts, respond to

criticisms, and adequately explain its rationale. 42 U.S.C.

7607(d)(2)-(6). In fulfilling those obligations, EPA employed

the decisional criteria that the agency has long used to

ensure consistency in its NAAQS decisions. See p. 5, supra.

For example, in setting the annual PM,, standards, EPA

took account of the “types of health evidence” and the “kind

and degree of uncertainties.” EPA identified a scientific

criterion applicable to epidemiological studies—statistical

significance to the 95% confidence level—to determine “how

much uncertainty [was] too much” within the narrow range

under consideration. See Pet. App. 10a; 62 Fed. Reg. at

38,675-38,676; 61 Fed. Reg. at 65,642 n.8; see note 10, supra.

The scientific evidence showed statistically significant

positive associations between PM,; and adverse health

effects in locations where PM,, ranged from 15.7 to 21 pg/m’.

— —

— — 3

See pp. 10-11, supra. But no study showed a statistically

significant association between adverse health effects and

PM, in any area with an annual PM,, level below 15.7 g/m.

See 62 Fed. Reg. at 38,676; PM App. 3506-3521. EPA

therefore set the annual PM,, standard at 15 pg/m*, which

EPA determined would be requisite to protect public health

with an adequate margin of safety.

In the ozone rule, EPA selected the standard based pri-

marily on consideration of “the nature and severity of the

health effects,” “the size of the sensitive population at risk,”

and, again, the “types of health evidence.” EPA recognized

that a standard of 0.09 ppm would not protect public health

with an adequate margin of safety. See pp. 13-14, supra.

EPA also recognized that its mandate is not to set standards

more stringent than requisite to protect against health

effects of public health significance. EPA identified impor-

tant and meaningful differences in the character of the

scientific evidence regarding risks—including the estimated

frequency and duration of adverse health effects—associated

with levels above and below 0.08 ppm. Those differences

amply justified the Administrator’s selection of the 0.08 ppm

level as requisite to protect public health with an adequate

margin of safety. E.g.,62 Fed. Reg. at en 61 Fed.

Reg. at 65,727, 65,730; see also pp. 13-15, supra.”

The record accordingly demonstrates that EPA did not

exercise unfettered discretion in promulgating the revised

PM and ozone standards. To the contrary, EPA explained in

detail, with reference to the scientific evidence in the record,

why it selected the challenged PM and ozone standards. The

court of appeals thus failed to appreciate the record before it

3 EPA and CASAC recognized that ozone has no apparent effects

threshold. See, e. g., 62 Fed. Reg. at 38,863. CASAC acknowledged that

fact when it commented that no “bright line” differentiated ozone levels

within the range of 0.07 ppm to 0.09 ppm. Ozone App. 238. CASAC’s com-

ment did not mean, however, that the public health effects were the same

at any level within the range. See 62 Fed. Reg. at 38,865.

in erroneously concluding that EPA claimed such wide

discretion that it could have set the new standards at

virtually any level. Cf. Overton, 401 U.S. at 416.

II. THE COURT OF APPEALS LACKED JURIS-

DICTION TO REVIEW EPA’S PREAMBLE STATE-

MENTS ON THE SCOPE OF ITS AUTHORITY TO

IMPLEMENT A REVISED OZONE STANDARD

Section 307(b)(1) of the CAA authorizes the D.C. Circuit

to review “action of the Administrator in promulgating any

[NAAQS]” and other “nationally applicable regulations

promulgated, or final action taken, by the Administrator.”

42 U.S.C. 7607(b)(1). In this case, the court of appeals

plainly had jurisdiction to review EPA’s promulgation of the

ozone NAAQS. The NAAQS, which consists of a specific,

two-paragraph rule, Pet. App. 104a, is final agency action.

The court of appeals erred, however, in concluding that it

also had authority to critique portions of EPA’s explanatory

preamble and thereby dictate the course of the agency’s

future implementation actions. The court of appeals’ broad

pronouncement that “EPA can enforce a revised primary

ozone NAAQS only in conformity with Subpart 2,” Pet. App.

8la, results from that court’s premature and unfocused

exploration of issues that were not properly before that

court.

EPA’s rulemaking addressed promulgation of a revised

ozone NAAQS. The issue of implementation arose in the

ozone case because participants in the rulemaking pro-

ceeding argued that, when Congress enacted the 1990

Amendments and included—in Section 181(a)(1) of Subpart

2—a scheme for implementing the then-current one-hour

ozone standard, Congress thereby implicitly prohibited EPA

from ever promulgating a revised ozone standard. See p. 15,

supra. Section 307(d)(6) of the CAA requires EPA to

respond to “significant comments.” 42 U.S.C. 7607(d)(6).

EPA accordingly addressed those arguments in the rule-

making preamble and, later, in its brief in the court of

appeals. EPA explained generally, as part of its demonstra-

tion why the Section 181(a) scheme does not prevent EPA

from promulgating a revised NAAQS, that the revised

standard could be implemented through Subpart 1. See

App., infra, la-Ga; 62 Fed. Reg. at 38,884-38,885.™

The court of appeals was obligated to address the specific

arguments that the rulemaking participants had raised in

their judicial challenge to EPA’s promulgation of a revised

ozone NAAQS. See 42 U.S.C. 7607(d)(7(B). The only issue

involving “implementation” before the court of appeals,

however, was whether the participants were correct that the

Section 181(a) scheme precluded EPA from promulgating

the revised standard. Once the court answered that

question in the negative, Pet. App. 34a-37a, its task was

done. It should not have gone on to consider prematurely

whether and how EPA could implement the revised

NAAQS.

The government objected, through petitions for rehearing

and rehearing en banc, to the court of appeals’ decision to

address an issue that was not properly before it. The court

responded by asserting that it had jurisdiction to address the

views that EPA expressed in the preamble because those

explanatory statements about the agency’s future intentions

independently satisfied the final agency action requirement

of Section 307(b) of the CAA. Pet. App. 77a-78a. That con-

clusion is wrong.

* Consistent with its position here, EPA explained in the rulemaking

that a] number of commentors submitted comments regarding

implementation issues that are not relevant to the Ozone NAAQS review.

Therefore, they are not being responded to in this document.” Ozone App.

223. EPA clearly recognized that such comments were premature and

would be addressed, if necessary, in later rulemakings.

A. EPA’s Preamble Statements Regarding Implementation

Authority Are Not “Agency Action” Within The

Meaning Of Section 307(b)(1) Of The Act

The court of appeals has undertaken to address prospec-

tively how to reconcile two complex portions of the CAA—

Subparts 1 and 2 of Part D—even though EPA has not yet

undertaken that task through rulemaking. The court justi-

fied its review on the basis that EPA stated, in an

explanatory preamble, how it intends to reconcile those

provisions. See 62 Fed. Reg. at 38,884-38,885 (App., infra,

la-6a). Section 307(b)(1), however, limits the court of

appeals to review of particular agency actions, such as

“promulgating any * * * [NAAQS)” and other “final action

* * * taken[] by the Administrator.” 42 U.S.C. 7607(b)(1).

The CAA does not define the phrase “action * * *

taken{] by the Administrator,” but its meaning can be

discerned from conventional principles of administrative law.

Cf. Harrison v. PPG Indus., Inc., 446 U.S. 578, 586 (1980).

The Administrative Procedure Act (APA) defines the term

“agency action” as “the whole or a part of an agency rule,

order, license, sanction, relief, or the equivalent or denial

thereof, or failure to act.” 5 U.S.C. 551(13); see 5 U.S.C.

701(b)(2). As this Court has indicated, the phrase “agency

action” is limited to discrete acts that affect legal rights. See

Lujan v. National Wildlife Fed’n, 497 U.S. 871, 891 (1990)

(“Under the terms of the APA, respondent must direct its

attack against some particular ‘agency action’ that causes it

harm.”); FTC v. Standard Oil Co., 449 U.S. 232, 247 (1980)

(“In general, the term encompasses formal orders, rules, and

interpretive decisions that crystallize or modify private

rights.”) (Stevens, J., concurring).

The CAA also draws a clear distinction between agency

action and the agency’s explanation of its action. For exam-

ple, a promulgated rule—a familiar form of agency ac-

tion—must be “accompanied” by “a statement of basis and

purpose” and “a response to each of the significant [public]

comments [on the proposed rule].” 42 U.S.C. 7607(d)(6).

That requirement facilitates judicial review of whether the

agency’s rule is “arbitrary, capricious, or an abuse of dis-

cretion,” 42 U.S.C. 7607(d)\(9). A court is entitled to set aside

the rule if it concludes that the agency’s rationale for the

rule is inadequate. But in that situation, the court invali-

dates the rule itself —viz., the agency’s action—and not the

agency's explanation for its action. See ibid.; see also 5

U.S.C. 706(2). The agency’s explanation is not itself “agency

action” that is independently subject to review. Cf. Califor-

nia v. Rooney, 483 U.S. 307, 311 (1987) (per curiam) (“This

Court ‘reviews judgments, not statements in opinions.’”)

(quoting Black v. Cutter Labs., 351 U.S 292, 297 (1956));

Herb v. Pitcairn, 324 U.S. 117, 126 (1945) (“our power is to

correct wrong judgments, not to revise opinions”).

In this case, EPA’s “action” is promulgation of the revised

ozone NAAQS, which consists of a discrete rule. See Pet.

App. 104a. The rule itself makes clear that the preamble

sets out the “reasons” for the rule. Ibid. The related

preamble statements at issue here (see App., infra, la-6a)

could properly be considered by the court of appeals only as

they relate to the agency action in question—promulgation

of the revised ozone NAAQS. Those statements do not

themselves constitute “agency action.” If they did, then

virtually any regulatory preamble that endeavors to explain

the basis for an agency’s action would arguably spawn

additional agency actions that are each potentially subject to

judicial review and revision. Congress surely did not

authorize courts to engage in that sort of broad and limitless

anticipatory oversight of CAA programs. See Standard Oil,

449 U.S. at 247-249 (Stevens, J., concurring).

B. EPA's Preamble Statements Do Not Constitute “Final”

Agency Action

Even if EPA’s preamble statements constituted “agency

action,” they do not constitute “final” agency action. In

Bennett v. Spear, 520 U.S. 154 (1997), this Court identified

two conditions that must be satisfieu for agency action to be

“final”: (1) it “must mark the ‘consummation’ of the agency’s

decisionmaking process”; and (2) it “must be one by which

‘rights or obligations have been determined,’ or from which

‘legal consequences will flow. Id. at 177-178. EPA's dis-

cussion of the Act’s implementation provisions in the

preamble does not satisfy either of those requirements.

The court of appeals improperly reconfigured the “con-

summation” prong by focusing solely on whether the plans

that EPA described in the preamble appeared tentative or

likely to change. See Pet. App. 77a-78a. Under Bennett,

however, the proper inquiry is not merely whether the

agency has any present intention to alter its position.

Rather, the question is whether the agency has consum-

mated its decisionmaking process. The answer necessarily

depends upon what steps the governing statute requires.”

When EPA’s preamble statements are considered in light

of the CAA’s implementation program, it is clear that they

do not constitute final agency action. EPA completed the

25 For example, the Court concluded in Standard Oil Co., supra, that

the action at issue—filing an administrative complaint—was not final

agency action under the relevant statutory process. The Court explained

that the action “is a prerequisite to a definitive agency position on the

question whether Socal violated the Act, but itself is a determination only

that adjudicatory proceedings will commence.” 449 U.S. at 241-242. Like-

wise, in cases involving rulemakings, the Court has concluded that agency

regulations are final if the agency has completed the applicable rule-

making procedures and promulgated a legally binding rule that completed

action within the context of the substantive regulatory program. See, e. g.,

Abbott Labs. v. Gardner, 387 U.S. 136, 149-152 (1967) (discussing cases).

Thus, the certitude of an agency’s statements, standing alone, does not

satisfy the consummation prong.

TEE VS —

statutory process for reviewing the existing ozone s

42 U.S.C. 7408(a), 7409(d), and reached a final —

ulgating the eight-hour ozone standard. EPA thus consum-

mated its decisionmaking process and took final agency

action in promulgating the NAAQS. 42 U.S.C. 7607(b)(1).

EPA, however, has hardly begun and has not yet completed

a in the CAA’s distinct process for implementing the

— — NAAQS, which requires additional rulemakin g

The CAA provides EPA up to three years after prom-

ulgating a revised NAAQS to designate all areas within the

Nation as attainment, nonattainment, or unclassifiable for

* As part of the ozone NAAQS rulemaking, EPA issued separate

, EPA 4

rule, — —— — — future enforcement of the one-hour

ozone 8 0 ight-h i

—— — eight-hour ozone NAAQS will replace. That

The 1-hour standards set forth in this section will no longe

an area once EPA determines that the area has air quality meeting

ar. r standard. Area designations are codified in 40 CFR part

Ibid. EPA issued that rule as a transition measure to reliev

; e areas that

are in compliance with the one-hour ozone standard from the obligation to

comply with both the old one-hour standard and the new eight-hour

standard. See 62 Fed. Reg. at 38,873. In the course of explaining that

— — —— in the preamble that Subpart 1 would apply to imple-

— on o new eight-hour ozone standard. Ibid. See App., infra,

Neither 40 C. F. R. 50.9(b) nor EPA’s related

provides a jurisdietional basis for the court of — —

EPA's authority to implement the eight-hour standard under Subpart 1.

As an initial matter, no party in this case challenged 40 C.F.R. 50.9(b), the

court of appeals accordingly did not review it, and thus it clearly was not

the predicate for the court of appeals’ ruling. In any event, 40 C.F.R.

50.9(b) merely addresses interim enforcement of the pre-existing one hour

standard. Neither 40 C. F. R. 50.9(b) nor EPA’s preamble statements de-

scribing it resolve whether or how Subparts 1 and 2, and other provisions

— — ., interact to limit EPA’s authority to implement the eight-

that standard. 42 U.S.C. 7407(d)(1).” At the same time, for

nonattainment areas, EPA must establish schedules for

States to submit state implementation plans. 42 U.S.C.

7502(b). EPA may establish classifications for nonattain-

ment areas and must establish their attainment dates. 42

U.S.C. 7502(a); see also 42 U.S.C. 7511(a)(1). States develop,

for EPA approval or disapproval, their SIPs to implement

the NAAQS by the applicable attainment dates. See 42

U.S.C. 7410(a) and (k), 7502(c). Under that statutory

structure, NAAQS implementation proceeds through a care-

ful decisionmaking process that includes designation, setting

dates for SIP submissions, classifying nonattainment areas,

developing SIPs, setting attainment dates, and obtaining

EPA’s approval of the SIPs. EPA’s expression of its views,

in a regulatory preamble, on some aspects of that future pro-

cess cannot reasonably be viewed as completing any of the

discrete steps that make up that process.

EPA did not take action in the rule under review to

designate, classify, or set attainment dates for any areas, to

set schedules for SIP submissions, or to approve or dis-

approve any SIP. Thus, EPA’s preamble statements do not

mark the consummation of any part of the agency’s imple-

mentation process. They do not conclude the agency’s

thinking on how it may implement the revised ozone stan-

dard, or precisely whether or how implementation of the

revised eight-hour standard may be affected by any Subpart

2 provisions. EPA’s deliberations on those matters are

ongoing and have not yet resulted in final agency action that

is ripe for judicial review.

The preamble statements also do not satisfy the second

Bennett requirement that “the action must be one by which

‘rights or obligations have been determined,’ or from which

27 Congress slightly modified this schedule in 1998 with respect to the

revised standards at issue here. Pub. L. No. 105-178, §§ 6101(b), 6102(c),

61038(a)-(b), 112 Stat. 463-465.

3 S EE ere eg

‘legal consequences will flow.’” 520 U.S. at 178. The court of

appeals concluded that EPA’s preamble statements respect-

ing future implementation were final action because by “pro-

mulgating a revised ozone NAAQS the EPA has triggered

the provisions of §§ 107(d)(1) and 172, which impose a

number of requirements upon the states * * * [and] those

areas that do not comply will ultimately be required to do

so.” Pet. App. 78a. Any obligations triggered by pro-

mulgation of the NAAQS arise, however, regardless of what

EPA said, or did not say, in the preamble about imple-

mentation. No legal consequences flow from the preamble

statements themselves. EPA’s views on implementation will

produce tangible legal consequences only when EPA takes

actual steps to implement the NAAQS through the

prescribed rulemaking processes. Affected parties will be

able to obtain judicial review of EPA’s judgments on

implementation once EPA takes final action that actually

creates new legal obligations.

C. EPA’s Preamble Statements Regarding Implementation

Of The Eight-Hour Ozone Standard Are Not Ripe For

Review

Even if EPA’s preamble statements were final agency

action, that purported agency action would not be ripe for

judicial review. The ripeness doctrine serves “to prevent

the courts, through avoidance of premature adjudication,

from entangling themselves in abstract disagreements over

administrative policies, and also to protect the agencies from

judicial interference until an administrative decision has

oeen formalized and its effects felt in a concrete way by the

challenging parties.” Ohio Forestry Ass’n v. Sierra Club,

523 U.S. 726, 732-733 (1998) (quoting Abbott Labs., 387 U.S.

at 148-149).

The ripeness doctrine “is drawn both from Article III

limitations on judicial power and from prudential reasons for

refusing to exercise jurisdiction.” Reno v. Catholic Soc.

Servs., Inc., 509 U.S. 48, 57 n.18 (1993). To determine

whether a controversy is ripe a court must “evaluate both

the fitness of the issues for judicial decision and the hardship

to the parties of withholding court consideration.” Texas v.

United States, 523 U.S. 296, 301 (1998). “A claim is not ripe

for adjudication if it rests upon ‘contingent future events

that may not occur as anticipated, or indeed may not occur at

all.. Id. at 300.

The court of appeals’ concerns regarding how to reconcile

Subparts 1 and 2 are not yet fit for review because, at this

stage, the matter is too abstract, as demonstrated by the

breadth and generality of the court’s conclusion. EPA has

neither fully developed its interpretation nor attempted to

exercise its authority to implement the eight-hour ozone

standard. See, e.g., Ohio Forestry, 523 U.S. at 732-738;

Abbott Labs., 387 U.S. at 148-149.

The interplay among Sections 107(d), 172, and 181, and

other relevant provisions of the Act, is complex. As we have

explained, EPA expressed views on selected implementation

provisions of the Act to respond to comments in the ozone

rulemaking that those provisions negate EPA’s NAAQS

revision authority. A court’s consideration of whether and

how Section 181(a) and other sections of Subpart 2 may

affect EPA’s authority under the various provisions of

Subpart 1 would be on much surer footing if the reviewing

court had the benefit of EPA’s full explanation of how and

why it has implemented the revised ozone standard in a

particular way, after the completion of a relevant decisional

process (including any required public notice and comment)

that actually implements the standard.”

2% The Court has recognized that deferring review is appropriate

where “the need for some further procedure, some further contingency of

application or interpretation . serve[s) to make remote the issue

which was sought to be presented to the Court.” Simon v. Eastern Ky.

Welfare Rights Org., 426 U.S. 26, 51-52 (1976) (Brennan, J., concurring)

(quoting Poe v. Ullman, 367 U.S. 497, 528 (1961) (Harlan, J., dissenting);

The case for deferring review is especially strong here

because the resolution of any tension between the various

provisions in Subparts 1 and 2 may depend upon the cir-

cumstances of the particular nonattainment area at issue.

See, ¢.g., Pet. App. 40a-4la (expressing concern regarding

the interplay and future application of Sections 172(a) and

181(a)(1) on Los Angeles). Deferring review of those imple-

mentation issues would allow EPA the opportunity to work

through the various implementation provisions in concrete

settings, reconcile conflicts, make policy judgments, and

apply its expertise as necessary to resolve ambiguities in the

statute. See Ohio Forestry, 523 U.S. at 733-734; Chevron

U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-845 (1984).

Judicial intervention at this point would also “den[y] the

agency an opportunity to correct its own mistakes and to

apply its expertise.” Standard Oil, 449 U.S. at 242. Defer-

ring review would facilitate future judicial review by reduc-

ing the issues to manageable proportions. The importance of

a concrete setting for judicial review is underscored by the

court’s own confusion regarding EPA’s interpretation, com-

pare Pet. App. 43a-44a, with id. at 80a-81a and id. at 87a-88a,

its reliance upon predicted future outcomes in particular

areas, id. at 40a-4la, and the extreme breadth and lack of

clarity of the court’s ultimate conclusion that “EPA can

enforce a revised primary ozone NAAQS only in conformity

with Subpart 2,” id. at 81a.

Finally, deferring review will not work substantial hard-

ship. EPA’s expression of its views in the preamble created

see, e. g., Toilet Goods Ass n v. Gardner, 387 U.S. 158, 163-164 (1967)

(interpretive rule not ripe for review). In this case, “[djetermination of

the scope * * * of legislation in advance of its immediate adverse effect

in the context of a concrete case involves too remote and abstract an in-

quiry for the proper exercise of the judicial function.” International

Longshoremen s & Warehousemen’s Union v. Boyd, 347 U.S. 222, 224

(1954). See ACLU v. FCC, 823 F.2d 1554, 1577 (D.C. Cir. 1987), cert.

denied, 485 U.S. 959 (1988); Office of Communication of United Church of

Christ v. FCC, 826 F.2d 101, 106 (D.C. Cir. 1987).

no obligations that adversely affect any parties’ day-to-day

operations, and the parties will have ample opportunity to

bring their legal challenge when any harm is more imme-

diate and certain. See Lujan, 497 U.S. at 891; Ohio Forestry,

523 U.S. at 733-734; Toilet Goods Ass’n v. Gardner, 387 U.S.

158, 164 (1967).

III. THE COURT OF APPEALS IMPROPERLY RE-

STRICTED EPA’S AUTHORITY TO IMPLEMENT

THE REVISED OZONE STANDARD

If this Court were to reach the merits of the court of

appeals’ decision respecting implementation, it should re-

verse that decision. The court of appeals correctly upheld

EPA’s authority to revise the ozone NAAQS, and it cor-

rectly concluded that the CAA requires EPA to designate all

areas of the Nation as attainment, nonattainment, or unclas-

sifiable areas for the revised standard. Pet. App. 34a-37a.

The court erred, however, in concluding that EPA could not

enforce a more protective ozone standard in those desig-

nated areas. See id. at 37a-44a. On rehearing, the court

modified its views and concluded that “EPA can enforce a

revised primary ozone NAAQS only in conformity with

Subpart 2.” Id. at 81a. Judge Tatel explained in his partial

concurrence that the panel’s revised decision allows EPA to

enforce its revised ozone standard under Subpart 1 in an

area only after that area attains the one-hour standard under

Subpart 2. Id. at 89a (Tatel, J., concurring). But even under

that view, the court of appeals’ decision is incorrect.

As we explain below, EPA reasonably interprets the CAA

to require that EPA implement a revised ozone standard

under Subpart 1. The revised NAAQS is a National

Ambient Air Quality Standard that should apply throughout

the entire Nation, for all members of the public, including

those that reside in areas that do not currently attain the

one-hour standard. There is no warrant for categorically

requiring that EPA ensure compliance with the very one-

hour ozone standard that it found inadequate to protect

public health before it can require efforts to attain the more

protective revised ozone NAAQS.

A. The Clean Air Act Authorizes EPA To Implement The ~

Revised Ozone NAAQS Under Subpart 1 Of Part D

Title I of the CAA, 42 U.S.C. 7401-7515 (1994 & Supp. III

1997), governs the promulgation and implementation of

all NAAQS, and it directs that the NAAQS be attained

“as expeditiously as practicable.” 42 U.S.C. 7502(a)(2),

7511(a)(1). Part A expressly requires EPA to reconsider

and, if appropriate, revise the NAAQS— including the pre-

existing one-hour ozone standard—every five years. 42

U.S.C. 7409(d)(1); Pet. App. 34a. Subpart 1 of Part D, which

governs implementation for “Nonattainment Areas in Gen-

eral,” sets out specific provisions for implementing revised

NAAQS. 42 U.S.C. 7502(a)(1). It follows that EPA’s revised

ozone NAAQS would be subject to implementation under

Subpart 1. The court of appeals’ counter-intuitive conclusion

—that the revised ozone NAAQS must be implemented in

conformity with Subpart 2, which addresses the former

ozone NAAQS—conflicts at the outset with the basic

framework of the Act.

Subpart 1’s specific language reveals that the court’s

construction is wrong. Section 172(a) establishes classifi-

cations and attainment dates for all areas designated non-

attainment “pursuant to section [107(d)] with respect to any

* * * revised standard, including a revision of any standard

in effect on November 15, 1990.“ 42 U.S.C. 7502(a)(1)(A).

Section 172(a)(1)(A)’s reference to “any” revised standard

includes a revision of the one-hour ozone standard, because

that standard was “in effect on November 15, 1990.” See 40

C.F.R. 50.9 (1990). Thus, Section 172(a), on its face, makes

clear that Subpart 1 governs the selection of classifications

and attainment dates for a revised ozone NAAQS.

The court of appeals questioned that interpretation

because Sections 172(a)(1)(C) and 172(a)(2)(D) provide that

EPA’s classification and attainment date-setting authority

under Section 172(a) does not apply to “nonattainment areas

for which classifications [or “attainment dates”) are specifi-

cally provided under other provisions of [Part Dl.“ 42 U.S.C.

7502(a)(1(C) and (a)(2)(D). See Pet. App. 37a. The court of

appeals noted that Section 181(a)(1), in Subpart 2 of Part D,

provides that “each area designated nonattainment for ozone

pursuant to [Section 107(d)}” is to be classified and given an

attainment date under its Table 1. 42 U.S.C. 7511(a)(1). See

Pet. App. 38a. In the court’s view, Section 181(a)(1) dictates

that all areas that are designated as nonattainment for ozone

under Section 107(d), including areas designated under the

revised ozone NAAQS, are subject to Subpart 2’s provisions.

Id. at 38a-89a. Congress, however, adequately answered the

court’s concern over those seemingly competing references.

Section 181(a)—which is contained in Subpart 2 of Part

D—“specifically provide[s]” classifications and attainment

dates for only a particular subset of ozone “nonattainment

areas.” Section 181(a)’s caption states that the Section

provides “Classification and attainment dates for 1989

nonattainment areas.” 42 U.S.C. 7511(a) (emphasis added).

The 1989 nonattainment areas are, of course, the areas that

were subject to the one-hour ozone standard then in force.

Congress enacted Subpart 2 out of concern over the con-

tinuing nonattainment of the one-hour ozone standard that

existed when it enacted the 1990 Amendments. It plainly

crafted Section 181(a)(1) to address that specific problem.

The title of Section 181(a) clarifies that Section’s reach and

resolves any confusion about whether Subpart 2 governs

implementation of the revised ozone NAAQS. See INS v.

National Ctr. for Immigrants’ Rights, Inc., 502 U.S. 183, 189

(1991); Mead Corp. v. Tilley, 490 U.S. 714, 723 (1989); FTC v.

Mandel Bros., 359 U.S. 385, 388-389 (1959).

The court of appeals’ contrary conclusion would lead to

unworkable and absurd results. For example, Section

181(a)(1) sets attainment dates and classifications based on

an area’s “design value,” which is an air quality measure that

specifically applies to the one-hour ozone standard that was

in existence in 1990. See 42 U.S.C. 751 1(aK ). It would

make no sense—and, indeed, would be impossible—to clas-

sify areas and set their attainment dates for the revised

NAAQS’s eight-hour standard using an air quality measure-

ment based upon one-hour averaging. The eight-hour

NAAQS rests on an entirely different averaging meth-

odology, statistical form, and concentration. See 40 C.F.R

50.10 & Pt. 50 App. I, 14 2-3. a.

In addition, Section 181(a) calculates attainment dates for

areas based upon a fixed number of years from 1990. See 42

U.S.C. 7511(a)(1) (Table 1). Section 181(a)(1) makes refer-

ence to 1990 because it establishes attainment dates for the

1989 nonattainment areas,” which had not attained the one-

hour ozone standard at the time of enactment of the 1990

Amendments. That timetable makes no sense in calculating

attainment dates for a revised NAAQS. Indeed many of

Section 181(a)(1)’s attainment dates, including those for

marginal,” “moderate,” and “serious” nonattainment areas

have already passed. See 42 U.S.C. 751 lla) (Table 1)” »*»n„n»

® See H.R. Rep. No. 490, 101st Con

H.R. . No. , g., 2d Sess. Pt. 1, at 197 (1990).

* 2 primary ozone standard, established to protect human beth be

— maximum hourly concentration of 0.12 parts per million (ppm) lie.

¢ one-hour ozone standard]. Compliance with the ozone standard is

— the basis of a ‘design value,’ which is the fourth highest one-

reading over three years.”). The court appeals correct!

— See Pet. App. 32a n.6. 1 5 1

The text of Section 181(b), 42 U.S.C. 78110 i

N 0 (o), S.C. ), provides furthe

evidence that Section 181 applies only to the implementation of the one.

hour standard. Section 181(b) recognizes that areas initially designated

shortly after enactment of the 1990 Amendments as “attainment” areas

for the one-hour ozone standard ma i

y be redesignated as “nonattainment”

if, for example, air quality in the area deteriorates. See 42 USC.

In light of those considerations, Section 181(a)(1) cannot

reasonably be construed to have “specifically provided” clas-

sifications and attainment dates for the eight-hour ozone

standard. Rather, the text and context of Section 181(a)

indicate that Congress intended Section 181(a)(1) to provide

classifications and attainment dates only for “1989 non-

attainment areas” that had been designated under the then-

current one-hour ozone standard. See 42 U.S.C.

7407(d)(1)(C) and (4A). EPA’s view that Congress in-

tended EPA to implement the revised NAAQS under Sub-

part 1 and to implement the former NAAQS under Subpart

2 represents, at a minimum, a permissible and reasonable

accommodation of the provisions entrusted to the agency’s

care. See, e.g., Chevron, 467 U.S. at 842-845.

B. Delaying Implementation Of The Revised NAAQS Until

The Previous Standard Is Attained Conflicts With The

Clean Air Act’s Requirement That All NAAQS Be

Attained “As Expeditiously As Practicable”

The court of appeals also erred in its apparent conclusion

that EPA cannot implement the revised ozone NAAQS in an

area until that area has had an opportunity to meet the

attainment dates for the one-hour ozone standard. See Pet.

App. 89a. The court overlooked that the attainment dates

set out in Section 181(a)(1) establish the maximum period of

time allowed for attainment. See 42 U.S.C. 7511(a)(1). Both

7407d)( 3). Section 181(b) allows for adjustment of the attainment date set

out in Section 181(a)(1)’s “Table 1” in that circumstance. See 42 U.S.C.

7511(b). Section 181(b) makes no provision, however, for using Table 1 if

EPA promulgates a revised ozone standard and jesignates an area as

“nonattainment” under the revised standard. Section 181(b) expressly

applies only to areas that were initially designated as “attainment” for the

one-hour ozone standard pursuant to 42 U.S.C. 7407(d)(4) and are later

as “nonattainment” for that standard under 42 U.S.C.

7407(d\(3). See 42 U.S.C. 7511(b). Section 181(b) does not apply to de-

signations for revised NAAQS, which are made under 42 U.S.C.

7407(d)(1).

Subpart 1 and Subpart 2 require that all areas attain the

— as expeditiously as practicable.” CAA §§'172(a)(2),

1(aX(1), 42 U.S.C. 750 2c)“ 2), 7511(a)(1); see H.R. Rep. No.

490, 101st Cong., 2d Sess. Pt. at 1, at 229; S. Rep. No. 228

101st Cong., Ist Sess. 37 (1989). EPA accordingly is justified

in concluding that it should implement the revised ozone

uit the rn dcleh throughout the Nation in accordance

iming provisions set out i

— p t in Subpart 1. 42 U.S.C.

The court of appeals expressed concern that a practical

conflict could conceivably arise for the Los Angeles area

between Subpart 1’s deadline to attain the revised ozone

standard and Subpart 2’s attainment date for the one-hour

ozone standard. See Pet. App. 41a. It is entirely reasonable

however, for Congress to require that, once EPA determines

that a revised NAAQS is necessary to protect public health,

the revised NAAQS should be attained without avoidable

delay notwithstanding the timetable that Congress en-

— for the standard then in effect.

oreover, the court of appeals has overs

practical problem that the 4 — NAAQS —— -

we have noted, the deadlines for attainment in Section

181(a)(1) are only outer time limits for attaining the one-hour

standard. See 42 U.S.C. 7511(a)(1). Los Angeles would be

required to attain the revised NAAQS under Subpart 1 no

later than the same year that marks the outer time limit for

attaining Subpart 2’s one-hour ozone standard. Compare

CAA § 172(a)(2), 42 U.S.C. 75020) 2), with CAA § 181(a)(1)

and (5), 42 U.S.C. 7511(a)(1) and (5). That situation, how-

ever, does not necessarily pose any practical problems. For

simultaneous implementation of two or more NAAQS including

: , t

—_ the same pollutant. See, ¢.g., 40 C. F. R. 50.4(a)-(b),

example, it may be “practicable”’—and preferable from an

implementing State’s perspective—to achieve both the one-

hour ozone standard and the revised ozone standard at

approximately the same time. There is no reason to believe

that Congress intended to preclude that approach.

In any event, the question of how to reconcile any

competing compliance deadlines is clearly the type of issue

that should first be addressed by EPA through future final

action under the implementation process, including any

required public notice and opportunity for comment. EPA’s

determinations can then be subject to judicial review in the

appropriate court of appeals. See 42 U.S.C. 7607(b)(1). To

the extent that there is tension between Subparts 1 and 2, it

will be up to EPA to harmonize the applicable provisions,

and the courts must defer to EPA’s reasonable judgment on

the matter. Chevron, 467 U.S. at 845. Those issues,

however, are properly reserved for another day. Regardless

of how those provisions may ultimately be applied, they

certainly do not justify the court of appeals’ conclusion that

Congress prohibited EPA from implementing the revised

ozone standard in an area until it attains the very standard

that EPA found was not adequate to protect public health.

CONCLUSION

The judgment of the court of appeals should be reversed

and the case remanded for further proceedings.

Respectfully submitted.

Gary S. GUZY

General Counsel

GERALD K. GLEASON

MICHAEL L. Goo

JAN M. TIERNEY

KEVIN W. MCLEAN

Attorneys

Environmental Protection

Agency

JULY 2000

SETH P. WAXMAN

Solicitor General

Lois J. SCHIFFER

Assistant Attorney General

LAWRENCE G. WALLACE

Deputy Solicitor General

JEFFREY P. MINEAR

Assistant to the Solicitor

General

DAVID J. KAPLAN

MARY F. EDGAR

Attorneys

APPENDIX

Excerpts From Federal Register Notice:

National Ambient Air Quality Standards For

Ozone; Final Rule (62 Fed. Reg. 38,856 (1997))

1. In discussing its jurisdiction to review EPA’s imple-

mentation of the eight-hour ozone NAAQS (Pet. App. 77a-

78a), the court of appeals cited the following passage from

the preamble of the Federal Register Notice describing

EPA’s Final Rule: National Ambient Quality Standards For

Ozone:

D. 1990 Act Amendments

Contrary to the view expressed in some public

comments, EPA maintains that the provisions of subpart

2 of Part D of Title I of the Clean Air Act, enacted in 1990,

do not preclude EPA from revising the O, standard. The

provisions of subpart 2 simply do not limit EPA’s clear

authority under section 109 to revise the standard.

The basic contention of the commenters is that be-

cause the provisions of subpart 2 are linked to the current

I-hour, 0.12 ppm O, standard, they prohibit EPA from

revising the O, standard. These provisions, however, do

not lead to such a conclusion. Moreover, the view ex-

pressed in these comments ignores provisions indicating

that Congress believed that EPA could revise the O,

NAAQS.

At the outset, it should be noted that Congress ex-

pressly authorized EPA to revise any ambient air quality

standard in section 109. That section, which requires

EPA to review and revise, as appropriate, each NAAQS

every 5 years, contains no language expressly or im-

plicitly prohibiting EPA from revising a NAAQS. If

Congress had intended to preclude EPA from reviewing

and revising a NAAQS, which is one of EPA’s

(la)

fundamental functions, Congress would have specifically

done so. Clearly, Congress knew how to preclude EPA

from exercising otherwise existing regulatory authority

and did so in other instances. See section

202(b)(1(C\(expressly precluding EPA from modifying

certain motor vehicle standards prior to model year 2004);

section 112(b)(2)(preventing EPA from adding to the list

of hazardous air pollutants any air pollutants that are

listed under section 108(a) unless they meet the specific

exceptions of section 112(b)(2)); section 249(e)(3), (f) and

section 250(b)(limiting EPA’s authority regarding certain

clean-fuel vehicle programs). No such language was

included in either section 109 or elsewhere in the Act and

no such implication may properly be based on the

provisions of subpart 2 of Part D of Title I.

Second, other provisions of the Act expressly con-

template EPA’s ability to revise any NAAQS, and

provide no indication that such ability is limited to stan-

dards other than those whose implementation is the

subject of subparts 2, 3 and 4 of Part D. For example,

section 110(a)(2)(H{i) provides that SIPs are to provide

for revisions “from time to time as may be necessary to

take account of revisions of such national primary or

secondary ambient air quality standard * * *.” Section

107(d)(1)(A) provides a process for designating areas as

attainment, nonattainment, or unclassifiable “after

promulgation of a new or revised standard for any

pollutant under section 109 * .“ Section 172(e)

addresses modifications of national primary ambient air

quality standards. Finally, section 172(a)(1) expressly

contemplates that EPA may revise a standard in effect at

the time of enactment of the 1990 Clean Air Act

Amendments. Section 172(a)(1)(A) provides EPA with

authority to classify nonattainment areas on or after the

designation of an area as nonattainment with respect to

“any revised standard, including a revision of any

standard in effect on the date of the enactment of the

Clean Air Act Amendments of 1990.” Plainly, Congress

had no intention of prohibiting EPA from revising any of

the ambient standards in effect at the time of the

enactment of the 1990 amendments.

Third, the provisions of subpart 2 of Part D do not

support the contention that they somehow preclude EPA

from exercising its authority to revise the NAAQS under

section 109. The fact that Congress laid out an

implementation program for the O, standard existing at

the time of the 1990 amendments in no way suggests that

Congress intended to preclude EPA from exercising the

authority it provided EPA to revise the NAAQS when

the health data on which EPA bases such decisions war-

ranted a change in the standard. Contrary to this conten-

tion, section 181(a) does not preclude the designation of

areas as nonattainment for O, that have design values less

than 0.121 ppm. EPA has designated as nonattainment

numerous areas whose design value was less than 0.121

ppm, but which violated the existing 1-hour, 0.12 ppm O,

standard. These areas, referred to as “nonclassifiable

nonattainment areas,” include “submarginal” areas (i. e.,

O; nonattainment areas with design values below 0.121

ppm), (See 57 FR 13498, 13524-27, April 16, 1992). These

areas include areas that were designated nonattainment

prior to the 1990 amendments and whose nonattainment

designation Congress required to be continued after 1990.

See section 107(d)(1)(C)(i). Clearly, Congress did not

prohibit the designation of areas as nonattainment for O,

with design values below 0.121 ppm; in fact, in some cases,

Congress required it. Furthermore, the position

advanced by the commenters would mean that, in effect,

Congress in the 1990 amendments legislatively revised

the then-existing 1-hour, 0.12 ppm O, standard to a 0.121

ppm standard. There is no indication that Congress in-

tended to do that.

In addition, the fact that Congress directed EPA to use

“the interpretation methodology issued by the Admini-

strator most recently” before the date of the enactment of

the Clean Air Act Amendments of 1990 in the context of

subpart 2 does not add any support to the commenters’

position; it merely shows that Congress intended the

existing 1-hour, 0.12 ppm standard to be implemented in a

specified way, not that Congress intended to preclude

EPA from using its otherwise applicable authority to

revise the standard.

The EPA also disagrees with the contention that

sections 172(a)(1)(C) and (a)(2)(D), which provide that the

general classification and attainment date provisions of

section 172 do not apply to areas for which classifications

or attainment dates “are specifically provided under other

provisions of this part,” support the conclusion that

Congress intended to prohibit EPA from revising the O;

standard. These provisions simply mean that where

Congress elsewhere provided for specific classifications

and attainment dates, as in the case of subpart 2

regarding the I-hour, 0.12 ppm standard, EPA is not to

modify those classifications or dates. The EPA is not pur-

porting to do this. These provisions do not lead to the

conclusion that because Congress established them for

the O, standard in effect at the time of the 1990

amendments, Congress meant that EPA could not revise

that standard in order to appropriately protect public

health.

EPA does not accept the thesis that revising the O;

standard forces EPA to violate other provisions of the

Act and, therefore, is not an “appropriate” revision of the

standard under section 109. Revising the O; standard in

accordance with the language of section 109 does not

result in EPA violating any provision of the Act. On the

other hand, a determination by EPA that the O, standard

should not be revised, even though EPA concludes that it

needs to be revised to protect public health with an

adequate margin of safety, would violate section 109.

Also, EPA does not believe that carrying out the

provisions of section 109 to set a new O; standard to

protect public health with an adequate margin of safety

somehow “risks undermining both perceptions and reality

of the functioning of our democratic form of government.”

EPA is merely implementing the words of the Clean Air

Act, a statute passed by the Congress and signed by the

President. To refuse to revise the standard

notwithstanding the need to protect public health as

enunciated in section 109 would thwart the objectives of

those who passed and signed the Clean Air Act on behalf

of the American public.

Finally, for the reasons stated above, EPA’s analy-

sis of its ability to implement the revised O, standard

under the provisions of subpart 1 of Part D of Title I does

not support the view that Congress prohibited EPA from

revising the standard. Congress clearly specified an

approach to the implementation of the 1-hour, 0.12 ppm O,

standard in the provisions of subpart 2 of Part D. EPA

believes that the clear and express linkage of that

approach to the 1-hour, 0.12 ppm standard indicates that

it may implement a revised O, standard in accord with the

general principles of subpart 1 of Part D, as informed by

the no-backsliding principle embodied in section 172(e).

That Congress directed specifically how EPA and the

States should implement the 1-hour, 0.12 ppm O, standard

does not carry with it the implication that Congress

intended to prohibit EPA from exercising its otherwise

clear and express authority to revise that standard in

order to carry out one of its fundamental missions, the

establishment of ambient air quality standards to protect

public health with an ample margin of safety. If Congress

had intended to prohibit EPA from exercising such a

fundamental authority it would have clearly specified (as

it did in other instances) that EPA could not do so.

The EPA also disagrees with the contention that a

revised O, standard may not be implemented for so long

as the current 1-hour, 0.12 ppm O; standard remains in

effect. The fact that the provisions of subpart 2 of Part D

are focused on the implementation of the current standard

does not mean that, if a new or revised O, standard is

promulgated pursuant to section 109, the new standard

could not simultaneously be implemented under the

provisions of section 110 and subpart 1 of Part D, which

apply regardless of the criteria pollutant of concern.

There is no language in sections 181 or 182 that precludes

the implementation of a different standard under other

authority; those provisions simply govern the implemen-

tation of the 1-hour, 0.12 ppm O, standard. EPA further

notes that it has historically had more than one primary

standard for criteria pollutants (e.g., annual and 24-hour

PM,, and sulfur dioxide standards, and 8-hour and 1-hour

CO standards) and believes that had Congress wanted to

preclude EPA from implementing two primary O, stan-

dards simultaneously it would have expressly precluded

EPA from doing so. Thus, EPA does not believe that it

must repeal the 1-hour, 0.12 ppm O, standard before it can

promulgate and implement a new primary O: standard.

62 Fed. Reg. 38,884-38,885 (1997).

2. The preamble of the Federal Register Notice also

describes EPA’s separate final rule, 40 C.F.R. 50.9(b), re-

specting future enforcement of the one-hour ozone NAAQS.

The preamble contains the following passage, which provides

an additional discussion of implementation of the ozone

NAAQS:

4. Final decision on the primary standard. After

carefully considering the information presented in the

Criteria Document and the Staff Paper, the advice and

recommendations of CASAC, public comments received

on the Proposal, and for the reasons discussed above, the

Administrator is replacing the existing 1-hour, 0.12 ppm

—— gy with a new 8-hour, 0.08 ppm primary

8 ard. Ihe new 8-hour standard will i

— — become effective

The 8-hour, 0.08 ppm primary standard will be met

at an ambient air quality monitoring site when the 3-year

average of the annual fourth-highest daily maximum 8-

hour average O, concentration is less than or equal to 0.08

ppm. Data handling conventions are specified in a new

A 4 * .

— I to 40 CFR part 50 as discussed in Unit VI

In the proposal, EPA proposed that the revocation

of the existing 1-hour O, standard be delayed for certain

purposes until EPA had approved State Implementation

Plans to implement the new 8-hour O, standard. EPA had

proposed continuing the applicability of the 1-hour

standard in this way in order to facilitate continuity in

public health protection during the transition to a new

standard. (See Memorandum from John S. Seitz to M

D. Nichols, November 20, 1996; Docket No. A-95-58 —

II- B-3.) Also, at the time of the proposal of the new 03

standard, EPA had proposed an interpretation of the Act

in the proposed Interim Implementation Policy (61 FR

65764, December 13, 1996) under which the provisions of

— — of part D of Title I of the Act would not apply to

sting O; nonattainm

— ent areas once a new O, standard

i In light of comments received regardi

interpretation proposed in the Interim — dea

Poliey, EPA has reconsidered that interpretation and now

believes that the Act should be interpreted such that the

provisions of subpart 2 continue to apply to O

nonattainment areas for purposes of achieving —

of the current I-hour standard. As a consequence, the

provisions of subpart 2, which govern implementation of

the I-hour O; standard in O; nonattainment areas, will

continue to apply as a matter of law for so long as an area

is not attaining the 1-hour standard. Once an area attains

that standard, however, the purpose of the provisions of

subpart 2 will have been achieved and those provisions

will no longer apply. However, the provisions of subpart

1 of part D of Title I of the Act would apply to the

implementation of the new 8-hour O, standards.

To facilitate the implementation of those provisions

and to ensure a smooth transition to the implementation

of the new 8-hour standard, the I-hour standard should

remain applicable to areas that are not attaining the 1-

hour standard. Therefore, the I-hour standard will

remain applicable to an area until EPA determines that it

has attained the I-hour standard, at which point the 1-

hour standard will no longer apply to that area.

62 Fed. Reg. 38,873 (1997).

This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.