Air Quality Standards:
The Decisionmaking Process

John E. Blodgett, Larry B. Parker, and James E. McCarthy
Environment and Natural Resources Policy Division

Updated June 24, 1998

97-722 ENR CONTENTS

CONTENTS

Summary
Introduction
Background
Criteria Air Pollutants
National Ambient Air Quality Standards

Primary Standards

"Margin of Safety"

Secondary Standards

Setting NAAQS

Setting and Reviewing NAAQS

Criteria Document
Staff Paper
Clean Air Scientific Advisory Committee

The Administrator's Decision

The Evidence
The Criteria

Health

Sensitive populations
Adverse health effect
Exposure evaluation and risk assessment
Margin of safety

Costs

Promulgating NAAQS

The Administrative Rulemaking Process

Notice of Proposed Rulemaking
Public Comment
Promulgation of the Rule
Regulatory Impact Assessments

Costs and Benefits - Executive Order 12866
Unfunded Mandates - Unfunded Mandates Reform Act
Small Business - Regulatory Flexibility Act
Other Regulatory Impact Assessments

Consultations - Office of Management and Budget; Other Departments and Agencies

Judicial Review

Appendix I. The NAAQS-Setting Process
Appendix II. Setting NAAQS - a Typical Chronology (Ozone)

Summary

The decisions by the Administrator of the Environmental Protection Agency (EPA) in July 1997 to revise ambient air quality standards (NAAQS) for ozone and particulate matter have refocused attention on the criteria and the process by which these decisions are made. Controversy over the new standards, other concerns about the Clean Air Act (CAA), and the expiration in 1998 of authorizations for appropriations in the statute, suggest that the Congress may soon consider amendments to the CAA. If so, the NAAQS decisionmaking process will likely command attention, particularly whether costs should be considered in setting NAAQS. Because of the role the NAAQS dispute might play in bringing amendments onto the legislative agenda, this report provides background on the processes and procedures for setting and revising NAAQS. It lays out the steps of the decision process and identifies the statutory criteria established by the Act for setting NAAQS.

The process by which EPA today sets NAAQS is the result of many year's evolution as the CAA was amended. The resulting multistage process for setting a NAAQS repeats regularly, as the Act requires each NAAQS to be reviewed every 5 years using the same process, to ensure that the standard is based on the most recent scientific information. The basic steps of the process are as follows:

· The listing by EPA of a pollutant that is emitted from numerous or diverse mobile or stationary sources and that endangers public health.
· The preparation of a "criteria document" that summarizes the scientific information relevant to the pollutant; this document is formally reviewed by a Clean Air Scientific Advisory Committee (CASAC).
· The preparation of a "staff paper" that summarizes the criteria document and lays out policy options for the Administrator; it is also reviewed by CASAC.
· Based on the criteria document, the staff paper, and CASAC's "closure letters," the Administrator proposes a NAAQS; this proposal is published in the Federal Register, a "docket" created, and an opportunity for public review and comment provided. And,
· The Administrator's final decision, "which, in the judgment of the Administrator, ... [is] requisite to protect the public health" [CAA, § 1 09(b)(1)].

The CAA spells out requirements for the criteria document, the CASAC review, the basis on which the Administrator chooses the standard, and the procedural process for promulgating the standard. EPA administratively added the preparation of a "staff paper"; in addition, Executive Order 12866 requires a Regulatory Impact Analysis (RIA), although the economic analysis is essentially irrelevant to the decision on the standard. Also, a number of regulatory assessment requirements in law other than the CAA impinge on the process - with debatable impact.

Several aspects in the NAAQS-setting process have been the foci of attention in the past and might be revisited: these include the Act's requirement that NAAQS be set to protect health with an adequate margin of safety, without consideration of costs; the process for verifying the scientific underpinnings of a proposed standard; the boundaries on the Administrator's judgment in accounting for risk and uncertainty in setting NAAQS; EPA's responsiveness to public comments; and the extent to which EPA must respond to requirements exogenous to the CAA that direct EPA to consider costs or other impacts of its regulations.

Introduction

The decisions by the Administrator of the Environmental Protection Agency (EPA) in July 1997 to revise the national ambient air quality standards (NAAQS) for ozone and particulate matter (PM) refocused attention on the criteria and the process by which these decisions are made. The new standards have been attacked both as overly stringent and as inadequately protective of health; as ignoring costs and as giving costs too much deference; as going beyond what is scientifically conclusive; and as failing to be sufficiently precautionary.1

These controversies, along with other concerns about the Clean Air Act (CAA) and the expiration in 1998 of the authorizations for appropriations in the statute, suggest that the Congress may soon consider amendments to the CAA. If so, the NAAQS decisionmaking process will likely command considerable attention, including how scientific evidence is used and whether costs should be considered in setting NAAQS. Because of discrepancies in views on what transpired - or should have transpired - in EPA's development of the ozone and PM proposals, this report provides background on the processes and procedures for setting and revising NAAQS. It lays out the steps of the decision process and identifies the statutory criteria established by the Act for NAAQS, to aid the reader's understanding of the Act's policy for NAAQS. It does not evaluate the decisionmaking process nor assess EPA's decisions on the ozone and PM NAAQS; nor does it address the several other categories of pollutants (e.g., hazardous air pollutants) or other standards-setting activities under the Act.

Background

The process by which EPA sets and revises NAAQS evolved over many years. Initially, federal air quality law focused on supporting state programs, through the conduct of research (a central, federal research program was more efficient than 50 state research efforts) and through technical and financial support (regulation was seen as a state and local matter). By the late 1960s, the federal research effort, located in the National Center for Air Pollution Control, Public Health Service, Department of Health, Education, and Welfare (HEW), included the preparation of "criteria" - a summary of scientific knowledge concerning selected air pollutants - and "guidelines" a summary of control technologies. These criteria and guidelines were to support state programs to control air pollution.

As environmental awareness heightened in the late 1960s, the federal role enlarged. With the Clean Air Act Amendments of 1970, the federal clean air program was moved to the newly created EPA 2 and reconstituted, with the federal government becoming responsible for establishing "national ambient air quality standards" for air pollutants endangering public health and resulting from numerous or diverse mobile or stationary sources. The states remained primarily responsible for developing implementation plans to attain and maintain compliance with those national standards. Major amendments in 1977 and 1990 refined the NAAQS setting and implementation process. The 1977 amendments formally established the Clean Air Scientific Advisory Committee (CASAC) and the 5-year review process. The 1990 amendments increased federal guidance to states in implementing existing NAAQS.

Thus the present process for setting and revising NAAQS consists of the statutory steps incorporated in the CAA over a series of amendments. In addition, several other steps of varying degrees of import have been added by the EPA, by executive orders, and by subsequent regulatory reform enactments by the Congress. The steps are depicted in appendix I; for an example chronology of the steps, see appendix II. The documentary language spelling out those steps, along with explanatory notes, follows.

Criteria Air Pollutants

The pollutants for which NAAQS are set are often called "criteria pollutants." This term reflects the evolution of the process. Before there were NAAQS, the Air Quality Act of 1%7 (a predecessor of the CAA) required the Federal government to list air pollutants and to prepare "criteria" a report summarizing scientific evidence concerning their health effects. The states then set standards. Thus the air pollutants for which NAAQS were later set were originally air pollutants for which the Office of Air Quality in HEW prepared "criteria." The current language specifying the listing of "criteria" air pollutants, as modified by the 1970 and 1977 amendments to the CAA, is as follows..

The Administrator shall publish, and shall from time to time thereafter revise, a list which includes each air pollutant - (A) emissions of which, in his judgment, cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare; [and] (B) the presence of which in the ambient air results from numerous or diverse mobile or stationary sources........[CAA §108(a)(1)]

With the Clean Air Act Amendments of 1970, the EPA became responsible for determining national ambient air quality standards for the "criteria pollutants" those of such national scope in release or effect that national standards are appropriate. Also, EPA was to assist states in attaining these standards through grants and technical assistance,3 and could impose sanctions on states for failures to fulfill their obligations. At present, six pollutants are designated "criteria pollutants" for which NAAQS have been set: particulate matter (PM), ozone (03, a key measure of smog), nitrogen dioxide(NO2 or, inclusively, nitrogen oxides, NOx), sulfur oxides (SOx, or, specifically, S02), carbon monoxide (CO), and lead (Pb).

National Ambient Air Quality Standards

The Administrator....... shall publish....... regulations prescribing a national primary ambient air quality standard and a national secondary ambient air quality standard for each air pollutant for which air quality criteria have been issued ....[CAA §109(a)(1)(A)]

A NAAQS is a uniform, national standard establishing the maximum permissible concentration of an air pollutant in the ambient air - the "portion of the atmosphere, external to buildings, to which the general public has access." 4 The CAA directs the Administrator to set a NAAQS at a level that provides protection from adverse effects on the public health and welfare. The Act provides for "primary standards" to protect health with a margin of safety and for "secondary standards" to protect welfare.

Primary Standards

National primary ambient air quality standards... shall be ambient air 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. [CAA § 1 09(b)( 1)]

An ambient air quality standard... should be the maximum permissible ambient air level of an air pollution agent or class of such agents (related to a period of time) which will protect the health of any group of the population. [Senate Report No.91-1196, p.10]

As stated in § 109, a NAAQS defines the acceptable concentration of an air pollutant in the ambient air necessary to protect health. As discussed later, costs are not considered in setting primary standards. Areas - defined as air quality control regions - complying with the standard are designated "attainment areas" and areas in which the pollutant exceeds the standard are designated "nonattainment areas." An area can be in attainment for one air pollutant and out of attainment for another.

Although a primary NAAQS has a federally enforceable deadline, a NAAQS does not itself establish what to do when concentrations exceed the standard (nor how to protect clean air in attainment areas). Other provisions of the CAA lay out the process of implementation (specifically, §110). For nonattainment areas, this includes monitoring ambient air quality to determine compliance; requiring states to prepare state implementation plans (SIPs) to bring areas not in compliance into compliance; and requiring states to implement their plans to achieve and maintain the NAAQS by a specified deadline. Federal measures to protect air quality include new source performance standards (§111), which are national standards on specified categories of new sources of selected air pollutants, and mobile source emission standards (§202). Also, the federal government continues to prepare "guidance documents" spelling out available control measures for the NAAQS pollutants. Finally, in attainment areas where the air is cleaner than NAAQS, the CAA establishes a program for new source permitting to "maintain" that clean air quality (Title I, Part C).

ENDNOTES

1 See CRS Report 97-8, Air Quality: Background Analysis of EPA'S 1997 Ozone and Particulate Matter Standards:

2 EPA was created by Reorganization Plan No.3 in 1970, reprinted as 42 U.S.C. §4321 note; the Agency went into operation December 2 of that year.

3 For example, in conjunction with setting NAAQS, the CAA requires EPA to prepare information on air pollution control technologies:

Simultaneously with the issuance of criteria ..., the Administrator shall, after consultation with appropriate advisory committees and Federal departments and agencies, issue to the States and appropriate air pollution control agencies information on air pollution control technologies, which information shall include data relating to the cost of installation and operation, energy requirements, emission reduction benefits, and environmental impact of the emission control technology. [CAA, § 108(b)( 1)]

The preparation of these "guidance documents," as they are known, is not reviewed in this report.

4 40 CFR §50.1(e). Air within workplaces is subject to regulation by the Occupational Health and Safety Administration.

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