Under Sections 108 and 109(b)(1) of the Clean Air Act, EPA must set National Ambient Air Quality Standards, commonly known as NAAQS, for six common air pollutants: carbon monoxide, lead, nitrogen dioxide, ozone, particle pollution, and sulfur dioxide. See 42 U.S.C. § 7408. For each pollutant, EPA identifies primary ambient air quality standards that are "requisite" to protect the public health. Id. § 7409(b)(1). Specifically, the EPA Administrator must "identify the maximum airborne concentration of a pollutant that the public health can tolerate, decrease the concentration to provide an 'adequate' margin of safety, and set the standard at that level." Whitman v. American Trucking Associations, Inc., 531 U.S. 457, 465, 121 S.Ct. 903, 149 L.Ed.2d 1 (2001). At least every five years, EPA must reevaluate the standards and, if appropriate, revise them. See 42 U.S.C. § 7409(d). Communities for a Better Environment v. EPA, 748 F. 3d 333 (DC Cir. 2014).
EPA must also promulgate secondary standards "requisite to protect the public welfare from any known or anticipated adverse effects" of those six pollutants in the ambient air. Id. § 7409(b)(2) (emphasis added). An adverse effect on public welfare includes adverse effects on "soils, water, crops, vegetation, ... animals, wildlife, weather, visibility, and climate," among other things. Id. § 7602(h). Communities for a Better Environment v. EPA, ibid.
The Clean Air Act places upon each state "the primary responsibility for assuring air quality within the entire geographic area comprising such State." 42 U.S.C. § 7407(a). In order to carry out that responsibility, each state must submit for EPA approval a state implementation plan (SIP) for the attainment of national air quality standards, § 7410(a)(1), and each SIP must contain a permitting or so-called "new source review" (NSR) program. See § 7410(a)(2)(C) (requiring "regulation of the modification and construction of any stationary source within the areas covered by the plan ..., including a permit program"). Oklahoma Dept. of Environmental Quality v. EPA, 740 F. 3d 185 (DC Cir. 2014).
Under Title V of the Clean Air Act, 42 U.S.C. §§ 7661-7700, every "major source" of pollution is required to obtain an operating permit for a fixed term. Id. § 7661a(a). Title V operating permits impose emission limitations, standards, monitoring requirements, compliance schedules, and other conditions on covered sources of pollution. See id. § 7661c. A source is considered "major" if it emits a certain amount of pollution. Id. § 7602(j). The Act also requires New Source Review (NSR) permits for a new or modified major source within an area not in attainment with National Ambient Air Quality Standards, if the source emits a certain amount of pollutants. Id. §§ 7502(c)(5), 7503. Under regulations promulgated by the Environmental Protection Agency ("EPA"), multiple pollutant-emitting activities are considered to be a single stationary source if they are, inter alia, "adjacent." 40 C.F.R. § 71.2, § 52.21(b)(5)-(6). National Envtl. Development Association v. EPA, 752 F. 3d 999 (DC Cir. 2014).
THIS CASEBOOK contains a selection of 57 U. S. Court of Appeals decisions that analyze and interpret provisions of the Clean Air Act. The selection of decisions spans from 2011 to the date of publication.