U.S. Supreme Court puts EPA to the test

Published February 1, 2001

The United States Supreme Court is expected to rule this summer on whether the United States Environmental Protection Agency may consider compliance costs, as well as health effects, when it sets national ambient air quality standards for ozone and particulate matter under the Clean Air Act (CAA).

The issue arises from two cases—American Trucking Association et al. v. Browner and Browner v. American Trucking Association et al.—which the Court has consolidated for its review.

The Court will consider whether Congress, by enacting a vague statutory provision, gave EPA regulatory powers so unbridled that they amount to an unconstitutional delegation to EPA of Congress’s law-making powers. Moreover, the Court will evaluate EPA’s efforts to promulgate health-based standards in the face of scientific uncertainty about the nature and gravity of the health risks caused by air pollutants.

At issue are provisions of the Clean Air Act that require EPA to establish National Ambient Air Quality Standards (NAAQSs). Those standards represent the maximum levels of certain air pollutants allowable in outdoor air. State governments are required to set and enforce limits on the emissions of those pollutants from specific stationary sources to ensure the allowable pollutant levels are not exceeded. The standards also influence the controls placed by EPA upon emissions from mobile sources such as cars, trucks, trains, airplanes, boats, snowmobiles, and even lawn mowers.

In 1997, EPA issued revised NAAQSs for two air pollutants: ozone and particulate matter. Ozone is formed by the reaction in sunlight of nitrogen oxides and volatile organic compounds. The NAAQS previously established by EPA for ozone was 0.12 parts per million averaged over a one-hour period. The 1997 revised standard was 0.08 parts per million averaged over an eight-hour period.

Particulate matter takes many forms. Typically, coarse particulate matter consists of larger particles often created by travel on gravel and dirt roads and landscape grading. Fine particulate matter is often created by combustion. The NAAQS previously established by EPA for particulate matter was an annual arithmetic mean of 50 micrograms per cubic meter for particles larger in diameter than 10 micrometers. EPA kept this level in its 1997 revisions for so-called “coarse” particles, but added a new one of 15 micrograms per cubic meter, annual arithmetic mean, for fine particles—those below 2.5 micrometers in diameter.

More than 103 corporations and industry trade associations filed a court challenge to the proposed new NAAQSs in the Court of Appeals for the District of Columbia, which struck down both the ozone and particulate matter regulations. The Supreme Court agreed to review the Court of Appeals’ decision.

According to the Court of Appeals, Congress had delegated its legislative power to EPA when it enacted Section 109(b)(1) of the Clean Air Act. In that statute, Congress directs EPA to set NAAQSs at levels which “in the judgment of the [EPA] Administrator, . . . and allowing an adequate margin of safety, are requisite to protect the public health.” In that provision, the Court of Appeals stated, Congress failed to articulate an “intelligible principle” to limit EPA’s discretion and power to establish NAAQS. Thus, the Court of Appeals found Congress had delegated to EPA its legislative power under the United States Constitution to “make all Laws.”

As noted by the Court of Appeals, EPA could have cured this defect by establishing its own “intelligible principle,” e.g., it would promulgate air quality standards based upon “population affected, severity and probability.” No such principle had been articulated and adopted by EPA, the Court of Appeals held.

But the court also questioned whether guiding principles could be established, because the language of the statute seems to require EPA to ignore all factors other than health effects. Thus, the statute may be read to give EPA no choice but to establish a zero-risk, zero-emission policy.

At oral argument in the Supreme Court in November, EPA contended the “requisite to public health language” in the Act authorizes it to exercise its judgment to set standards stringent enough to reduce serious medical conditions caused by inhalation of pollutants, such as lung inflammation, but that EPA need not address trivial health effects such as coughing. Several justices questioned whether the statutory language established any basis for these distinctions.

Industry advocates argued before the Court that Congress could not have intended to direct EPA to enact a zero-emission standard, and that the term “public health” and other provisions in Section 109 of the Act necessarily mean EPA was to include a cost-benefit analysis of the standards. Any other construction of the statute is incorrect, industry advocates argued, because a zero-emission standard would lead to deindustrialization of the country, and thus a negative impact on the public health.

The ozone and particulate matter standards are further flawed, industry advocates told the Court, because EPA’s own scientists have recognized that “associations between O3 [ozone] exposure and chronic health impacts have not been sufficiently demonstrated in humans.” EPA also refused to take into account information about the beneficial effects of ground-level ozone in reducing human exposure to UV radiation.

The science panel established by the CAA, the Clean Air Scientific Advisory Committee, reviewed EPA data on ozone and found it impossible to agree on a standard justifiable on public health grounds.


Maureen Martin is an attorney in private practice in Chicago.