CRS Report for Congress
Received through the CRS Web
The Supreme Court Upholds EPA Standard-
Setting Under the Clean Air Act: Whitman v.
American Trucking Ass’ns
Robert Meltz
Legislative Attorney
American Law Division
James E. McCarthy
Specialist in Environmental Policy
Resources, Science and Industry Division
On February 27, 2001, the Supreme Court handed down its decision in Whitman
v. American Trucking Associations, a challenge to EPA’s promulgation in 1997 of
revised national ambient air quality standards for ozone and particulates under the Clean
Air Act. On the broader issues, the Court ruled that (1) the Act’s provisions governing
the setting of primary (health-protective) ambient standards did not transgress the
“nondelegation doctrine,” a moribund constitutional principle that the court below had
resurrected, and (2) the Act bars EPA from considering implementation costs when it
sets primary national ambient standards. On a narrow issue, the Court held that EPA
had not been justified, in promulgating its ozone implementation plan, in applying only
the Act’s nonattainment-area subpart of general application, rather than a subpart specific
to ozone nonattainment. As a result, the Court charged the agency with developing a
“reasonable interpretation” accommodating both subparts. Such accommodation is likely
to prove a difficult task, however, and almost certainly once adopted will generate
further legal challenges.
On February 27, 2001, the Supreme Court handed down its eagerly awaited decision
in Whitman v. American Trucking Associations.1 The case stems from EPA’s
controversial promulgation in 1997 of revised national ambient air quality standards
(NAAQSs) for ozone and particulates, under the Clean Air Act (CAA). More
fundamentally, the legal theories in the case raise basic questions about standard-setting

1 121 S. Ct. 903 (2001). The decision adjudicated both EPA’s petition (No 99-1257) from the
decision below, and an industry cross-petition (No. 99-1426).
Congressional Research Service The Library of Congress

under the Clean Air Act and the constitutional limits on congressional delegation to
agencies of standard-setting authority.
NAAQSs lie at the very heart of the Clean Air Act. These standards prescribe
maximum pollutant concentrations for ground-level, outdoor air, and have been
promulgated by EPA for six pollutants,2 including ozone and particulates. The NAAQSs
determine the stringency of emission limits that each state must impose on individual
stationary sources of the six pollutants, to achieve the NAAQSs within its borders.
NAAQSs come in two forms: “primary NAAQSs” protect the public health, while
“secondary NAAQSs” protect the public “welfare” (non-public health effects).3 Once a
NAAQS has been promulgated, EPA must review it (and the “criteria documents” on
which it is based) every 5 years, and make such revisions “as may be appropriate.”4
In 1997, EPA revised the NAAQSs for ozone and particulate matter, making them
stricter. Given the perceived impact of these more stringent standards on the economy,
it was unsurprising that numerous legal challenges were brought – with two members of
Congress (Rep. Bliley and Sen. Hatch) filing as amici on the side of the challengers.
Pursuant to CAA requirement, the suit was filed in the U.S. Court of Appeals for the
District of Columbia Circuit.
In May, 1999, the D.C. Circuit ruled 2-1 that various deficiencies in EPA’s
promulgation of the two NAAQSs required that they be sent back to EPA for further
consideration.5 Among other things, the two-judge majority held that EPA’s reading of
the CAA section governing the setting of primary NAAQSs gave the agency too much
discretion, and thus violated the constitutional “nondelegation doctrine.” It also rejected
industry’s position that EPA, in arriving at primary NAAQSs, may consider the costs of
implementation. Finally, it ruled that EPA could not enforce its revised primary NAAQS
for ozone, owing to its being an eight-hour standard, rather than the one-hour standard
envisioned by CAA nonattainment-area provisions added to the Act in 1990 (see further
discussion on page 4). Five months later, the three-judge panel made minor modifications
in its opinion, but the full court refused to grant rehearing en banc (all the judges of the
court sitting).6 In May, 2000, the Supreme Court took the case.7
What the Supreme Court Said
The Supreme Court in American Trucking gave EPA a unanimous victory on the two
major issues in the case: consideration of costs, and nondelegation doctrine. Justice Scalia

2 40 C.F.R. §§ 50.4-50.12.
3 CAA § 109(b); 42 U.S.C. § 7409(b).
4 CAA § 109(d)(1); 42 U.S.C. § 7409(d)(1).
5 175 F.3d 1027 (D.C. Cir. 1999).
6 195 F.3d 4 (D.C. Cir. 1999).
7 120 S. Ct. 2003 (petition of EPA, granted May 23, 2000); 120 S. Ct. 2193 (petition of American
Trucking Ass’ns, granted May 30, 2000).

authored the opinion of the Court, with various justices writing separate concurrences to
note differences as to rationale, but not as to holding.
Consideration of costs. The Court affirmed the D.C. Circuit decision (which, in turn,
had endorsed existing case law of the circuit) in holding that when promulgating primary
NAAQSs, or revised primary NAAQSs, EPA may not consider the costs of implementing
the new standard. Health impacts, and health impacts alone, are to be the touchstone. The
governing standard in the statute, the Court said, made this clear: section 109(b)(1)
instructs EPA to set primary NAAQSs “the attainment and maintenance of which ... are
requisite to protect the public health” with an “adequate margin of safety.”8
Industry’s arguments that considerations other than the health impacts of pollutants
were cognizable could not overcome the directness of the above statutory text. For
example, industry contended that a very stringent NAAQS might close down whole
industries, thereby impoverishing the workers dependent on that industry and, in turn,
reducing their health. A health-based standard such as the primary NAAQS should include
these indirect impacts, industry asserted. The Court, however, pointed to numerous other
CAA sections where Congress had explicitly allowed consideration of economic factors,
concluding that had it intended to allow such factors under section 109(b)(1), it would
have been more forthright – particularly given the centrality of the NAAQS concept to the
CAA’s regulatory scheme. Looking for such a forthright “textual commitment” of
authority for EPA to consider costs, the Court found none. Its conclusion: section

109(b)(1) “unambiguously bars cost considerations from the NAAQS-setting process.”

Nondelegation doctrine. The most controversial portion of the D.C. Circuit’s
majority opinion was its embrace of a long-moribund constitutional principle known as the
“nondelegation doctrine.” This separation-of-powers doctrine derives from Article I of
the Constitution, which vests “[a]ll legislative Powers” in Congress. Not surprisingly,
the Supreme Court reads this vesting provision loosely, recognizing that Congress
routinely delegates quasi-legislative powers to non-Article I bodies. In particular,
Congress frequently commits to the specialized expertise of executive-branch agencies the
task of rulemaking in technical areas — such as air pollution control. The nondelegation
doctrine says that such delegations pass constitutional muster only if Congress gives the
agency an intelligible principle to guide its exercise of that authority.
The majority opinion below found that EPA had construed CAA section 109 so
loosely as to render it an unconstitutional delegation. The court agreed with the factors
used by the agency to assess the public health threat posed by air pollutants. But, it said,
EPA had articulated no intelligible principle for translating the factors into a particular
NAAQS, nor is one apparent from the statute. Given that both ozone and particulates are
non-threshold pollutants (adverse health effects occur at any concentration above zero),
some public health threat has to be tolerated if EPA is to avoid shutting down entire
industries. The agency, in the court’s view, had articulated no standard for determining
how much.
In invoking the nondelegation doctrine, the D.C. Circuit drew considerable attention.
It was the first time in 65 years that the nondelegation doctrine had been successfully used,

8 42 U.S.C. § 7409(b)(1).

and raised serious implications for how Congress delegates standard-setting authority to
agencies generally. Commentators pointed to other federal statutes – such as the Corps
of Engineers wetlands permitting program under the Clean Water Act, and the rulemaking
authority conferred by the Occupational Safety and Health Act – as vulnerable to
nondelegation-doctrine challenge, should the D.C. Circuit be affirmed on appeal.
The Supreme Court, however, reversed. The scope of discretion allowed by section
109(b)(1), the Court said, is “well within the outer limits of our nondelegation
precedents.” Under section 109(b)(1), primary NAAQSs are to set at levels “requisite”
to protect public health – “requisite” being argued by the United States, and accepted by
the Court, as meaning “sufficient, but not more than necessary.” To be sure, acknowledged
the Court, more guidance must be furnished the agency when the agency action is to have
broad scope – as here, where the revised NAAQSs affect the entire U.S. economy. But
even for sweeping regulatory schemes, the Court disclaimed any demand that statutes
provide a “determinate criterion” for saying precisely how much of the regulated harm is
too much. EPA may therefore be allowed discretion to determine how much of a public
health threat from ozone and particulates (recall, they are non-threshold pollutants) it will
tolerate at non-zero levels.9
Issues involving implementation of the revised ozone NAAQS. EPA lost, again
unanimously, on two issues arising from its policy for implementing the revised ozone
NAAQS in non-attainment areas. First, the Court rejected EPA’s argument that the policy
did not constitute final agency action ripe for review.
The Court then proceeded to the second issue: which CAA provisions govern the
ozone nonattainment-area implementation policy. This calls for some background. The
CAA imposes restrictions on nonattainment areas over and above those that the Act
imposes generally. These additional nonattainment-area restrictions are found in Title I,
Part D of the statute. Subpart 1 of Title D contains general nonattainment regulations that
apply to every pollutant for which a NAAQS exists. Subpart 2 of Part D addresses ozone
in particular. The dispute before the Court was whether Subpart 1 alone, or rather
Subpart 2 or some combination of Subparts 1 and 2, controls the implementation of the
revised ozone NAAQS in nonattainment areas. EPA, in its implementation policy, took
the former, Subpart-1-only course. The problem it faced was that Subpart 2 contemplated
a 1-hour ozone NAAQS, reflecting the ozone standard existing when Subpart 2 was
enacted in 1990. The revised ozone NAAQS, however, embodied an 8-hour standard.
Thus, some Subpart 2 provisions – in particular, the nonattainment-area classification
scheme that identified the requirements to be imposed depending on an area’s degree of
nonattainment – did not fit the new ozone NAAQS.
The Court found that EPA could not ignore Subpart 2 entirely, as it had done.
Whatever awkwardness of fit results from applying Subpart 2 to the new ozone standard,
it cannot, said the Court, justify “render[ing] Subpart 2's carefully designed restrictions on
EPA discretion utterly nugatory once a new standard has been promulgated ....” One
example of the discretion-limiting nature of Subpart 2: under Subpart 1, EPA may extend

9 The Supreme Court also soundly rejected the D.C. Circuit’s view that an unconstitutionally
standardless delegation of power can be remedied by the agency’s adoption of an interpretation
confining its own discretion. Congress, it said, must lay down the intelligible principle.

attainment dates for as long as 12 years; under Subpart 2, only 2 years (though Subpart
2's attainment deadlines stretch from 3 to 20 years depending on the severity of an area’s
ozone pollution). The Court left it to EPA “to develop a reasonable interpretation of the
[CAA’s] nonattainment implementation provisions” for the revised ozone NAAQS.
Legal Commentary
As to the nondelegation issue in American Trucking, EPA had gone to the Supreme
Court with the stronger arguments. It was not a foregone conclusion, however, that EPA
would win unanimously, as it did, even though the Court had on many occasions sustained
federal statutes containing standards as loose as, or looser than, that in the CAA governing
NAAQS setting. A few justices voting for at least some resuscitation of the nondelegation
doctrine was widely deemed a possibility on the ground that the Court in other areas
recently has revealed an interest in cabining congressional power and discretion – and not
only when the federal-state balance is implicated. Though it has been 66 years since the
last successful nondelegation-doctrine challenge, the Court has not hesitated to reverse
longstanding patterns in its constitutional jurisprudence when doing so furthered the
agenda of a contingent of the justices. Very likely, the Court’s refusal to bring back the
nondelegation doctrine stemmed in part from the Court’s view 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.”10
Moreover, the task of rewriting federal statutes necessitated by a reinvigorated
nondelegation doctrine might be one of daunting magnitude. From the environmental area
to antitrust to civil rights, federal laws abound that give agencies only the broadest of
Likewise, EPA had the better argument when it came to inclusion of costs in the
setting of NAAQSs. As a critic of using legislative history to divine the meaning of
statutes, Justice Scalia restricted his analysis for the Court to examination of the statutory
text itself. But the concurrence by Justice Breyer reveals a legislative history from the
enactment of the 1970 CAA that sides unambiguously with EPA’s keep-costs-out position.
For the foregoing issues then, the American Trucking decision largely restores the
status quo ante. As before the filing of this case, a lax jurisprudence under the
nondelegation doctrine and the impermissibility of considering costs in setting NAAQSs
are once again regarded as relatively settled law. Some commentators have noted the
Court’s refusal in American Trucking to defer to EPA’s interpretation of the CAA on
ozone standard implementation, and speculated that the legacy of the decision may lie in
its signalling a desire by the Court to lessen the degree of judicial deference to agency
decisionmaking. But it is premature as yet to draw this conclusion.
Remaining Issues
The Court’s decision in Whitman v. American Trucking is not the end of court
proceedings in the case. Numerous issues remain before the D.C. Circuit, and EPA’s next
attempt at an implementation plan may also be subject to court challenge.

10 Mistretta v. United States, 488 U.S. 361, 372 (1989).

Developing an implementation plan that embodies a “reasonable interpretation”of the
Act’s nonattainment implementation provisions for the revised ozone NAAQS, as the
Court mandated, is not an easy task. EPA has said that an 8-hour standard of 0.09 ppm11
would have “generally represent[ed] the continuation of the [old] level of protection,”
but the new standard is, in fact, set at a more stringent level of 0.08 ppm. Thus, the
statute’s classification system contains a gap that does not address areas with readings of

0.08 - 0.09 ppm.

A second problem relates to the setting of attainment dates. In the 1990
amendments, Congress was specific in setting dates of attainment that ranged from 3-20
years from the date of enactment, depending on the severity of an area’s ozone pollution.
The Court read this specificity as denying EPA its previous broad discretion in setting
attainment dates. But three of the Act’s deadlines (for Marginal, Moderate, and Serious
ozone nonattainment areas) have already passed. How EPA is to respond to this is
unclear. The Court itself noted that the Act’s method for calculating attainment dates
“seems to make no sense for areas that are first classified under a new standard after
November 15, 1990.”12
In these circumstances, it would seem likely that whatever approach EPA may take
will be subject to challenge by parties opposed to the new standards, with the potential for
several additional years of litigation before the issues are resolved. Whether Congress
should intervene to settle these matters is a possibility that few have discussed. While
logical in many respects, such a legislative clarification would open a number of issues
regarding the level of the new standards, the implementation measures to be required, and
the nature of EPA’s standard-setting authority that interested parties may not wish to have

11 National Ambient Air Quality Standards for Ozone; Final Rule, 62 Fed. Reg. 38,856, 38,858
(1997), quoted in Whitman at 121 S. Ct. 903, 918.
12 121 S. Ct. 903, 918.