American Trucking Associations, Inc. v. United States Environmental Protection Agency

The nondelegation doctrine permits Congress to confer regulatory authority only if it supplies an “intelligible principle” to guide the agency. EPA relied on sensible factors—such as the severity of an effect, the size of the affected population, the certainty of the evidence, and the existence of sensitive populations—but those factors did not establish how much risk was too much or when EPA should stop tightening a standard.

For pollutants believed to be non-threshold pollutants, such as ozone and likely particulate matter, some risk may exist at every exposure level above zero. EPA therefore needed a principle explaining why a particular nonzero level was “requisite” to protect public health with an adequate margin of safety. EPA’s explanations showed that higher pollution causes more harm and lower pollution causes less harm, but did not articulate a rule for choosing one point on that continuum over another.

EPA’s reasons for selecting 0.08 ppm rather than 0.07 ppm for ozone—greater uncertainty at lower exposures, less severe effects, CASAC’s recommendation, and proximity to natural background concentrations—did not themselves identify a legally binding stopping rule. The same problem applied to the PM standards: greater statistical confidence in health effects at some concentrations did not reveal how much uncertainty or harm EPA was entitled to tolerate.

The court distinguished earlier decisions sustaining EPA standards because those cases had not confronted the delegation issue. It also found EPA’s asserted discretion broader than the discretion upheld after remand in the OSHA lockout/tagout litigation, where OSHA had adopted a more bounded standard.

The court did not strike down § 109 immediately. Following its approach in Lockout/Tagout I, it gave EPA an opportunity to derive and adopt a more determinate construction, such as a framework that consistently weighs severity, probability, population affected, and uncertainty. EPA could alternatively report to Congress that no limiting principle could be developed and seek legislation.

The court treated its prior decision in Lead Industries Association v. EPA as controlling. Section 109’s text and legislative history make health effects from air pollutants, rather than economic costs or technological feasibility, the basis for primary NAAQS.

Section 109(d), governing periodic revision of standards, did not create a different rule. Its direction to make revisions “as may be appropriate” is immediately qualified by the requirement that revisions be made in accordance with §§ 108 and 109(b), which exclude implementation costs from the standard-setting judgment.

Although the Clean Air Scientific Advisory Committee must advise EPA about social, economic, and energy effects of attainment strategies, that information is relevant to EPA’s duty under § 108 to provide States with control-strategy information. It does not authorize EPA to use cost in selecting the health-based NAAQS themselves.

The claimed consequences of reduced funding for mine reclamation were downstream effects of the cost of complying with the ozone and PM standards. Under NRDC v. EPA, health effects caused by economic disruption, such as unemployment or compliance costs, are outside the health inquiry prescribed by § 109.

The court distinguished those indirect effects from ozone’s asserted direct health benefits as a shield against ultraviolet radiation. A direct health effect caused by the pollutant’s presence in ambient air belongs in EPA’s analysis; an effect caused by the expense of regulating the pollutant does not.

Congress expressly exempted Clean Air Act actions from NEPA’s central environmental-impact-statement requirement. Petitioners’ reliance on Portland Cement was misplaced because that decision addressed a different Clean Air Act provision before Congress enacted the relevant statutory exemption.

NEPA’s general directives concerning economic and environmental considerations could not override the Clean Air Act’s specific prohibition on considering implementation costs in setting NAAQS. The court applied the ordinary rule that a specific statutory scheme governs over a more general one.

To the extent NEPA’s alternatives and information provisions called for discussion of pollution-control methods, the Clean Air Act’s § 108 already supplied the functional equivalent by requiring EPA to provide States with available control-technology and alternative-method information.

The statute expressly bars courts from staying, enjoining, invalidating, or otherwise affecting a rule because an agency failed to prepare a regulatory impact statement. It also generally precludes judicial review of agency compliance with the Act’s requirements.

Even assuming an impact statement could be considered as part of the administrative record under another source of law, its principal added information would concern implementation costs. Because EPA may not consider those costs in setting NAAQS, the absence of such a statement could not establish that the standards were arbitrary or capricious.

The Regulatory Flexibility Act requires analysis of small entities subject to the agency’s proposed rule, not every small entity indirectly affected somewhere in the economy. Under the Clean Air Act, the NAAQS establish ambient-air targets, while States retain broad discretion to choose the emission controls in their state implementation plans.

EPA therefore reasonably concluded that the NAAQS themselves did not directly impose regulatory requirements on small businesses. If EPA later had to issue a federal implementation plan for a noncomplying State, it represented that it would perform the required flexibility analysis at that stage.

The court declined to defer to the Small Business Administration’s contrary view because SBA does not administer the Regulatory Flexibility Act. The 1996 amendments to that Act did not alter the statutory language on which the court’s prior direct-regulation rule rested.

Section 109(d) continued to require periodic review and revision of NAAQS, and the 1990 amendments did not repeal or limit that obligation for ozone. The anti-backsliding provision’s express treatment of a relaxed standard also presupposed that EPA retained authority to revise the ozone standard.

The numerical classifications in Subpart 2 were tied to the then-existing 0.12 ppm ozone standard, but they did not themselves enact that number as an unalterable NAAQS. The statute also continued to require EPA to designate areas as attainment, nonattainment, or unclassifiable after promulgating a revised standard.

Subpart 1’s general classification and attainment-date provisions do not apply where another part of the Act specifically supplies classifications and dates. Subpart 2 applies to each area designated nonattainment for ozone pursuant to § 107(d), and that language encompasses designations made after EPA revises the ozone standard.

The court found the statutory text, legislative evolution, and structure decisive. Congress enacted Subpart 2 to replace the unsuccessful one-size-fits-all ozone attainment regime with a detailed scheme that gave areas differing deadlines based on the seriousness of their ozone problems.

Allowing EPA to use Subpart 1 after adopting a more stringent ozone standard would undermine Congress’s calibrated deadlines. It could force even the most seriously polluted areas, including Los Angeles, to meet the new standard as quickly as or faster than the statutory date Congress allowed for achieving the older, less stringent standard.

Subpart 2 expressly addresses primary ozone NAAQS, not secondary standards, so it does not literally supply a separate classification scheme for revised secondary standards. Nonetheless, its structure reflects Congress’s judgment about what is practicable in reducing ozone concentrations.

Requiring compliance with a revised secondary standard before attainment of the older primary standard would conflict with that congressional judgment. Once an area attains the 0.12 ppm primary standard, however, EPA may require compliance with the revised secondary standard as expeditiously as practicable under the general provisions.

Section 108 requires air-quality criteria to reflect the latest scientific knowledge concerning “all identifiable effects” on public health or welfare caused by a pollutant’s presence in ambient air. That broad language includes beneficial effects; Congress’s use of the narrower term “adverse effects” in certain subclauses reinforced, rather than limited, the general command.

EPA’s argument that a substance labeled a “pollutant” could be evaluated only for harmful features was inconsistent with the statutory text. Nor did Title VI’s protection of stratospheric ozone resolve the asserted benefits of tropospheric, or ground-level, ozone.

EPA could not demand stricter proof of beneficial effects than it demanded for adverse effects. Because EPA itself had considered unquantified adverse effects where evidence was limited, it had to evaluate the studies on UV shielding under comparable evidentiary standards on remand.

The record contained sufficient evidence to support regulating coarse particles. Studies concerning volcanic ash and dust storms, along with multivariate analyses finding independent associations for PM10 and PM2.5, supported EPA’s conclusion that coarse particles could produce health effects distinct from fine particles.

But PM10 measures both coarse particles and fine particles. Once EPA established a separate PM2.5 standard and recognized that the two fractions differed materially, using PM10 as a surrogate for coarse particles made the allowed level of coarse pollution depend arbitrarily on the amount of fine-particle pollution already present.

EPA’s justifications did not solve that problem. The fact that certain studies used PM10 did not eliminate the acknowledged confounding caused by fine particles; the combined PM10 and PM2.5 standards produced double regulation of fine particles and potential underregulation of coarse particles; and the convenience of an existing PM10 monitoring network was not a permissible health-based reason for choosing an ill-fitting indicator.

Both the earlier total-suspended-particulate standards and the later PM10 standards included particles 2.5 micrometers in diameter and smaller. In many areas, fine particles made up a substantial component of PM10 pollution.

EPA’s decision to focus more specifically on fine particles reflected developing scientific knowledge about distinct health risks. It was an authorized refinement of an existing particulate-matter standard, not the initial regulation of a separate pollutant.

Section 108 authorizes regulation where emissions may reasonably be anticipated to endanger public health or welfare. The statutory language does not demand laboratory-level proof explaining every causal pathway before EPA may act.

Numerous epidemiological studies from varied locations found statistically significant associations between airborne particulate matter and adverse health effects. That body of evidence was sufficient under the Act and the court’s precedent permitting reasonable extrapolations from reliable evidence.

The court did not resolve the broader challenge to the level of the secondary PM2.5 standards because the nondelegation remand required EPA to reconsider its standard-setting principles. It did, however, decide the statutory question that would guide EPA on remand.

The Act’s regional-haze provisions aim to remedy visibility impairment in designated national parks and wilderness areas even where NAAQS are attained. That separate program would be unnecessary if secondary NAAQS had to eliminate all adverse visibility effects, so Congress did not require NAAQS alone to do all of that work.