Chapter 2. National Air Quality Standards

Theodore L. Garrett and Sonya D. Winner

Editors' Summary: On November 15, 1990, President Bush signed into law the Clean Air Act Amendments of 1990, the first comprehensive changes to the Act in 13 years. During the intervening months since its enactment, EPA has geared up, streamlined, and commenced its rulemaking processes to accommodate the regulatory burden the new law places on the Agency. As amended by the 1990 amendments, the Clean Air Act instructs EPA to promulgate 27 rules during each of the first two years. However, EPA must do much of its interpretation and rulemaking of the new Act's mandates without the aid of a comprehensive legislative history, because Congress rushed to get the 1990 amendments passed before the end of the 101st Congress. The minimal conference report and other reports related to passage of the amendments have already proved troublesome where the language Congress used is ambiguous. For example, litigation and political pressure have embroiled EPA's WEPCo rulemaking, which addresses how the amended Act's new source performance standards and new source review programs are to be applied to electric utilities' plans to renovate existing facilities. This may be only the tip of the struggles that EPA will face in implementing the new law.

In this three part series of Articles, the authors provide a comprehensive analysis of the Clean Air Act, from its origins through the 1990 amendments and their impacts. In Part I, the authors discuss the history of the Clean Air Act and provide a section-by-section overview of its provisions. In addition, they explain the Act's focus on national air quality standards, provisions for state implementation plans, and the goal of bringing areas with dirty air into attainment of the standards.

Parts II and III, planned for publication in the next two to three months, will address the 1977 amendments, EPA's post-1987 attainment policy, comprehensive analysis of the 1990 amendments, and impacts of the 1990 amendments on regulatory agencies and industry.

[22 ELR 10165]

The cornerstone of air pollution control under the Clean Air Act is the national ambient air quality standards (NAAQS) promulgated by the U.S. Environmental Protection Agency (EPA). Although the NAAQS are not directly enforceable, they are the benchmark for emission limitations established by the states for those air pollutants that the Administrator determines may endanger public health or welfare.¹ This chapter examines each step of the NAAQS process.

I. Overview of Air Quality Standards

The NAAQS prescribe the maximum permissible concentration of a harmful pollutant in the ambient air. Although the Act does not define "ambient air," 40 C.F.R. § 50.1(e) defines the term as "that portion of the atmosphere, external to buildings, to which the general public has access." This definition was paraphrased with apparent approval by the U.S. Supreme Court in Train v. NRDC.²

There are two kinds of NAAQS. Primary standards prescribe the maximum permissible concentration of a pollutant in the ambient air "requisite to protect the public health."³ Secondary standards specify a level of air quality "requisite to protect the public welfare from any known or anticipated adverse effects."⁴ EPA has established NAAQS for sulfur oxides, particulate matter, carbon monoxide, ozone, nitrogen dioxide, and lead.⁵

The promulgation of NAAQS is a three-step process. First, the Administrator publishes a list of air pollutants.⁶ Second, the Administrator issues "air quality criteria" describing the kind and extent of the effects on public health and welfare that may be expected from the pollutants listed.⁷ At the same time, the Administrator proposes NAAQS for the pollutants.⁸ Third, after an appropriate opportunity for public comment on the proposed standards, the Administrator promulgates final primary and secondary standards.⁹

The Act also establishes a timetable for the review and revision of criteria and standards.¹⁰ The 1977 amendments¹¹ to the Act directed the Administrator to review and revise the existing criteria and standards by December 31, 1980, and to continue to review the criteria and standards at five year intervals after that date.¹² The 1990 amendments¹³ had little, if any, impact on the procedure for establishing NAAQS.

II. Listing Air Pollutants

Section 108(a)(1)¹⁴ describes the standards the Administrator is to follow when listing air pollutants. To list a substance as an air pollutant, the Administrator must determine that (1) the substance is an "air pollutant" as defined in § 302(g);¹⁵ (2) the pollutant is emitted from numerous or diverse mobile or stationary sources; and (3) emissions from such sources cause or contribute to air pollution that may endanger public health or welfare. Once the Administrator finds that a substance in the ambient air endangers public health or welfare, ambient air quality standards must be promulgated.¹⁶

Air Pollutant. Section 302(g) provides:

The term "air pollutant" means any air pollution agent or combination of such agents, including any physical, chemical, biological, radioactive (including source material, special nuclear material, and by-product material) substance or matter which is emitted into or otherwise enters the ambient air. Such term includes any precursors to the formation of any air pollutant, to the extent the Administrator has identified such precursor or precursors for the particular purpose for which the term air pollutant is used.¹⁷

This broad definition of "air pollutant" gives the Administrator the authority to list a substance as an air pollutant if it is in the ambient air and meets the requirements of § 108(a)(1).

Stationary and Mobile Sources. Section 108(a)(1)(B) requires that the substance be emitted from numerous mobile or stationary sources.¹⁸ Congress intended that standards be established for pollutants that are "generally present in the ambient air in all areas of the nation" and "are generally detectable through monitoring devices and systems."¹⁹

The Clean Air Act differentiates between pollution from numerous and diverse sources and pollution that poses specific dangers in the area immediately surrounding the source of the pollution.²⁰ Air pollutants that endanger health or [22 ELR 10166] welfare but that are confined to the area of the emission source and are not generally detectable in the ambient air are regulated either as hazardous pollutants under § 112²¹ or pursuant to standards of performance under § 111²² for new stationary sources.

Endanger Public Health or Welfare. The Administrator must also conclude, "in his judgment," that the emissions of the pollutant may "cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare."²³ The legislative history refers to "the necessarily judgmental element in the task of predicting future health risks of present action and … confer[s] upon the Administrator the requisite authority to exercise such judgment."²⁴ In a dictum in one D.C. Circuit case, however, Judge Wright indicated that § 108 requires an actual adverse effect and actual harm rather than a prediction of harm.²⁵

Although authority granted to the Administrator is broad, "[t]he Administrator's judgment must … remain subject to restraints of reasoned decision making…."²⁶ Congress intended to give the Administrator authority to exercise his judgment while requiring that the judgment be rational and subject to adequate judicial review of its reasonableness.

III. Listing Procedure and Judicial Review

The Act describes no administrative procedure for listing of air pollutants under § 108, and the judicial review provisions of § 307 make no reference to review of the Administrator's determination to list an air pollutant.²⁷ A person wishing to challenge the basis for a listing could present data and views on that issue during the public comment period on the proposed standard. Judicial review of the listing of a pollutant under § 108(a)(1) would be available in a challenge to the subsequent promulgation of the NAAQS.²⁸

Although the listing process has not yet been challenged, the Administrator's duty to list has. In NRDC v. Train,²⁹ the U.S. Court of Appeals upheld a district court decision requiring the Administrator to place lead on the list of air pollutants under § 108(a)(1) of the Act. In defending the suit, EPA argued that § 108(a)(1)(C) gives the Administrator the power not to list a pollutant even though it meets the criteria of § 108(a)(1)(A) and (B).³⁰ EPA argued that the Administrator is required to list only pollutants for which he plans to issue air quality criteria. The Court held that EPA's interpretation was inconsistent with the language and the purpose of the Act, and directed the Administrator to list lead under § 108(a)(1) and to promulgate the NAAQS for lead.

IV. Issuance of Air Quality Criteria

Within 12 months of listing a substance as an air pollutant, the Administrator must issue "air quality criteria" for the substance.³¹ Air quality criteria are issued by the Administrator in lengthy background documents that are announced in the Federal Register notice when the NAAQS for the pollutant is proposed.³² Criteria documents produced by the Administrator must "accurately reflect the latest scientific knowledge useful in indicating the kind and extent" of a pollutant's effects on public health or welfare. The criteria document must include factors that alter the effect of a pollutant, the interaction of one pollutant with another, and any known or anticipated adverse effect on public welfare.³³ Judicial review of the criteria can be obtained in a proceeding for review of the air quality standards themselves.³⁴

V. Promulgation of the NAAQS

Within 12 months of listing as an air pollutant pursuant to § 108(a)(1), and simultaneously with the issuance of air quality criteria for that pollutant, the Administrator must propose national primary and secondary air quality standards for the pollutant.³⁵ After allowing a reasonable time for public comments, the Administrator must promulgate final standards "with such modifications as he deems appropriate."³⁶

The 1977 amendments to the Act created a more detailed administrative process for the promulgation of the NAAQS.³⁷ These procedures include submitting written comments; providing an opportunity for an informal oral presentation; establishing a docket and administrative record; and providing for EPA responses to significant comments, criticisms, and new data submitted in oral presentations.

A. Promulgation of Primary Standards

Section 109(b)(1) defines primary NAAQS as "ambient air [22 ELR 10167] quality standards the attainment and maintenance of which in the judgment of the Administrator, based on such criteria and allowing an adequate margin of safety, are requisite to protect the public health."³⁸ The scientific basis for setting a primary NAAQS is found in the air quality criteria promulgated at the same time as the proposed standard. The criteria document issued by the Administrator at the time the NAAQS is proposed sets forth the basic scientific and medical data on which the Agency relies.

This relationship between the air quality criteria and the prescribed levels in the standard was at issue in Kennecott Copper Corp. v. EPA.³⁹ In that case, the court remanded the standard for sulfur oxides to EPA and directed the "Administrator to supply an implementing statement that will enlighten the court" as to the basis on which he reached the numerical standard "from the material in the Criteria." The court concluded that without "sufficient indication of the basis on which the Administrator reached" the standard, it could not determine whether the Administrator's action was an abuse of discretion or an error of law. The Administrator must thus supply a reasoned basis in the scientific and medical data in the criteria document when setting primary or secondary ambient air quality standards.

The courts have held that the Administrator may not consider either the economic costs of setting a particular standard,⁴⁰ or the attainability and technological feasibility of the standards.⁴¹ The essential ingredient in the statutory definition of a primary standard is that the levels prescribed "are requisite to protect the public health."⁴² In enacting the 1970 and 1977 amendments to the Act, Congress indicated that the term "public health" includes "the health of susceptible individuals, as well as healthy adults."⁴³

Section 109(b)(1) also requires that primary standards provide "an adequate margin of safety." The Senate committee stated at the time of the 1970 amendments: "[M]argins of safety are essential to any health-related environmental standards if a reasonable degree of protection is to be provided against hazards which research has not yet identified."⁴⁴

B. Promulgation of Secondary Standards

Section 109(b)(2) requires that secondary ambient air quality standards be set at a level, based on the criteria, that is "requisite to protect the public welfare from any known or anticipated adverse effects associated with the presence of such air pollutant in the ambient air."⁴⁵ The key phrase here is "requisite to protect the public welfare." "Public welfare" as defined in § 302(h)⁴⁶ includes effects on soils, water, crops, wildlife, weather, economic values, and personal comfort and well-being. The statute requires the Administrator to protect the public "from any known or anticipated adverse effects" that may result from the presence of a pollutant in the ambient air. The reference to "known or anticipated adverse effects" suggests the possibility of a secondary standard that is based on adverse effects that cannot be demonstrated,⁴⁷ similar to the adequate margin of safety for primary standards.

As a practical matter, the primary standards have been more important than secondary standards. Of the six pollutants for which there are primary standards, in four cases the secondary standard is exactly the same as the primary standard. (These four cases are particulate matter, ozone, nitrogen dioxide, and lead.) In the fifth case, carbon monoxide, there is no secondary standard. In only one case, sulfur dioxide, is there a separate secondary standard.⁴⁸

1. A state implementation plan (SIP) sets limits for specific facilities or categories of sources within the state to assure that the NAAQS will be achieved and maintained in each air quality control region in the state. The background and significance of the NAAQS under the Clean Air Act (CAA) is discussed in Train v. NRDC, 421 U.S. 60, 63-68, 5 ELR 20264 (1975).

2. Id. at 65, 5 ELR at 20264.

3. CAA § 109(b)(1), 42 U.S.C. § 7409(b)(1), ELR STAT. CAA 18 (emphasis added).

4. CAA § 109(b)(2), 42 U.S.C. § 7409(b)(2), ELR STAT. CAA 18 (emphasis added).

5. See 40 C.F.R. pt. 50 (1991).

6. CAA § 108(a)(1), 42 U.S.C. § 7408(a)(1), ELR STAT. CAA 16.

7. CAA § 108(a)(2), 42 U.S.C. § 7408(a)(2), ELR STAT. CAA 16.

8. CAA § 109(a)(2), 42 U.S.C. § 7409(a)(2), ELR STAT. CAA 18.

9. CAA § 109(a)(1)(B), 42 U.S.C. § 7409(a)(1)(B), ELR STAT. CAA 18.

10. CAA § 109(d)(1), 42 U.S.C. § 7409(d)(1), ELR STAT. CAA 19.

11. Clean Air Act Amendments of 1977, Pub. L. No. 95-95, 91 Stat. 685.

12. See EDF v. Thomas, 870 F.2d 892, 900, 19 ELR 20660 (2d Cir.), cert. denied sub nom. Alabama Power v. EDF, 110 S. Ct. 537 (1989). EPA has found it difficult to act within the five-year revision cycle. For example, EPA proposed revisions for visibility impairment from particulate matter in 1984. 42 Fed. Reg. 10408 (March 20, 1984). No final action had been taken on this standard as of April 1990. NRDC v. EPA, 902 F.2d 962, 986 (D.C. Cir. 1990).

13. Clean Air Act Amendments of 1990, Pub. L. No. 101-549, 104 Stat. 2399, ELR STAT. CAA6-186.

14. 42 U.S.C. § 7408(a)(1), ELR STAT. CAA 16.

15. 42 U.S.C. § 7602(g), ELR STAT. CAA 133.

16. CAA § 109(a)(2), 42 U.S.C. § 7409(a)(2), ELR STAT. CAA 18; see also NRDC v. Train, 545 F.2d 320, 325, 7 ELR 20004 (2d Cir. 1976).

17. 42 U.S.C. § 7602(g), ELR STAT. CAA. 133 (emphasized text was added to Act by 1990 amendments).

18. 42 U.S.C. § 7408(a)(1)(B), ELR STAT. CAA 16.

19. S. REP. NO. 1196, 91st Cong., 2d Sess. 9, 18 (1970).

20. Id. at 18.

21. 42 U.S.C. § 7412, ELR STAT. CAA 28.

22. 42 U.S.C. § 7411, ELR STAT. CAA 25; see infra chapters 7-8.

23. CAA § 108(a)(1)(A), 42 U.S.C. § 7408(a)(1)(A), ELR STAT. CAA 16.

24. H.R. REP. NO. 294, 95th Cong., 1st Sess. 51 (1977).

25. Ethyl Corp. v. EPA, 541 F.2d 1, 14, 6 ELR 20267 (D.C. Cir.), cert. denied, 426 U.S. 941 (1976).

26. H.R. REP. NO. 294, supra note 24, at 51. The reference to the procedural safeguards contained in § 305 is to the 1977 amendments to § 307 prescribing more detailed procedures for judicial review and administrative action under the Act. 42 U.S.C. § 7607, ELR STAT. CAA 136.

27. Section 307(d)(1) lists certain administrative actions by the Administrator as subject to the fairly detailed procedural steps set forth in that subsection. The promulgation of any NAAQS under § 109 is included, but there is no reference to the listing of pollutants under § 108. 42 U.S.C. § 7607(d)(1), ELR STAT. CAA 137. Similarly, § 307(b)(1) lists certain administrative actions that are subject to judicial review, including the promulgation of any national primary or secondary NAAQS, but there is no reference to the listing of pollutants under § 108. 42 U.S.C. § 7607(b)(1), ELR STAT. CAA 136.

28. In National Asphalt Pavement Ass'n v. Train, 539 F.2d 775, 779 n.2, 6 ELR 20688 (D.C. Cir. 1976), the court stated that the listing of a category of sources under § 111(b)(1)(A) was subject to judicial review in the course of any proceedings brought for review of the resulting standard of performance promulgated under § 111(b).

29. 545 F.2d 320, 7 ELR 20004 (2d Cir. 1976).

30. Id. at 325.

31. CAA § 108(a)(2), 42 U.S.C. § 7408(a)(2), ELR STAT. CAA 16.

32. See e.g., 49 Fed. Reg. 10408 (March 20, 1984).

33. CAA § 108(a)(2), 42 U.S.C. § 7408(a)(2), ELR STAT. CAA 17.

34. See NRDC v. EPA, 902 F.2d 962, 988 (D.C. Cir. 1990), Kennecott Copper Corp. v. EPA, 462 F.2d 846, 850, 2 ELR 20116 (D.C. Cir. 1972).

35. CAA § 109(a)(2), 42 U.S.C. § 7409(a)(2), ELR STAT. CAA 18.

36. CAA § 109(a)(1)(B), 42 U.S.C. § 7409(a)(1)(B), ELR STAT. CAA 18.

37. CAA § 307(d), 42 U.S.C. § 7607(d), ELR STAT. CAA 137.

38. 42 U.S.C. § 7409(b)(1), ELR STAT. CAA 18.

39. 462 F.2d 846, 850, 2 ELR 20116 (D.C. Cir. 1972).

40. Natural Resource Defense Council, Inc. v. EPA, 902 F.2d 962, 973 (D.C. Cir. 1990) (per curiam) (§ 109 does not permit EPA to consider the costs of unemployment in promulgating the NAAQS).

41. American Petroleum Inst. v. Costle, 665 F.2d 1176, 1185, 11 ELR 20916 (D.C. Cir. 1981).

42. S. REP. NO. 1196, supra note 19, at 10; see NRDC v. EPA, 902 F.2d at 973; NRDC v. EPA, 824 F.2d 1146, 1157, 1159 (D.C. Cir. 1987) (en banc).

43. S. REP. NO. 1196, supra note 19, at 10; H.R. REP. NO. 294, supra note 24, at 50. The Administrator's action on the lead standard is instructive. He indicated that the "margin of safety considerations" led him to base the standard on the most critically sensitive subgroup within the population. Lead Indus. Ass'n v. EPA, 647 F.2d 1130, 1153, 10 ELR 20643 (D.C. Cir.), cert. denied, 449 U.S. 1042 (1980).

44. S. REP. NO. 1196, supra note 19, at 10.

45. 42 U.S.C. § 7409(b)(2), ELR STAT. CAA 18.

46. 40 U.S.C. § 7602(h), ELR STAT. CAA 133.

47. In Ethyl Corp. v. EPA, 541 F.2d 1, 6 ELR 20267 (D.C. Cir.), cert. denied, 426 U.S. 941 (1976), for example, Judge Wright contrasted this phrase in § 109(b)(2) with the wording in § 108(a)(1)(A), which prior to the 1977 amendments referred to "an adverse effect on public health and welfare" without the modifier "known or anticipated." Id. at 14 n.20, 6 ELR at 20273 n.20. Judge Wright interpreted this difference to mean that for the purpose of listing a pollutant under § 108(a)(1)(A) there had to be a determination of actual harm, whereas the "known or anticipated" language of § 109(b)(2) was intended to "prescribe a margin of safety."

48. 40 C.F.R. pt. 50 (1991).