06/26/2018 - CleanLaw Podcast - EPA Mission Tracker - Regulatory Rollbacks

Modifying the Air Quality Standards Review Process with Janet McCabe

Click here for a full transcript of this episode.

Listen below to our podcast featuring Janet McCabe, former Acting Assistant Administrator for the EPA Office of Air and Radiation and current Assistant Director for Policy and Implementation at Indiana University’s Environmental Resilience Institute and a Senior Law Fellow at the Environmental Law and Policy Center.

Janet discusses the National Ambient Air Quality Standards, the importance of reviewing those standards every five years, and the changes Trump’s EPA has made to the review process in its Back-to-Basics memo.


The National Ambient Air Quality Standards (NAAQS) are the foundation of America’s progress towards cleaner air, and setting them is EPA’s fundamental obligation under the Clean Air Act. Thanks to these standards, air quality in almost every US city is far better than it was in the 1970s. Basing the NAAQS in peer-reviewed science is essential to the success of this process. As both the Clean Air Act requires, and the Supreme Court has confirmed, considerations of cost are excluded from the assessment of what levels of pollution are “safe” for public health.

By requiring EPA to review the standards every five years and determine whether a revision is necessary based solely on science, Congress tied improvement in public health protection to the advancement of science. Once new standards are set, the “action-based” provisions of the Clean Air Act are set in motion to reduce air pollution.

On May 9, 2018, Scott Pruitt signed a Memorandum, Back-to-Basics Process for Reviewing National Ambient Air Quality Standards. The memo undermines the integrity of the standard-setting process and severs the link between scientific advancement and air quality improvements and public health protection by:

  • Collapsing into one step a two-step sequence of first determining safe air quality levels and then designing the rules for achieving those levels
  • Elevating the importance of meeting deadlines over getting the science right
  • Introducing economic considerations
  • Amending a fundamental provision of the Clean Air Act without providing opportunity for public comment or judicial review

EPA sets the NAAQS for six “criteria pollutants,” which affect public health. These pollutants are: carbon monoxide, lead, ground-level ozone, nitrogen dioxide, particulate matter, and sulfur dioxide. EPA sets the NAAQS with an adequate margin of safety, considering sensitive populations like children, the elderly, and people with respiratory conditions.

The Clean Air Act requires EPA to review the NAAQS for each pollutant every five years. During this review, EPA can decide to keep the existing standards or to revise them. Congress intended the Clean Air Act to protect public health by establishing these reviews, which allow continual adjustments to pollution limits according to the best available information. After the NAAQS are set, then EPA can begin to consider how to achieve the standards from a technology perspective.

The “Back-to-Basics” process outlined in the May 9 memo will collapse these two steps – first considering public health and then considering technology – into one step. Administrator Pruitt alleges this change is required to speed up the process. While there have been efficiency changes to the NAAQS review process in the past, previous changes have safeguarded the thoroughness and scientific integrity of the process.

The “Back-to-Basics” memo also suggests EPA will consider economic effects during the NAAQS review process. The Clean Air Act authorizes EPA’s scientific advisory committee to provide advice on “…adverse public health, welfare, social, economic, or energy effects…” for compliance with the NAAQS. This statutory provision relates to EPA’s drafting of the implementing regulations for states. This step traditionally happens after the NAAQS are already set. The list of additional considerations is not for the creation of the NAAQS. But the May 9 memo indicates that EPA now believes that provision is relevant to the NAAQS review. Considering economic effects during the NAAQS review itself would directly conflict with the Supreme Court’s ruling on the issue. In Whitman v. American Trucking Associations, Inc., the Court ruled that EPA is not allowed to consider the costs of implementation when setting the NAAQS.

The memo also proposes simultaneously issuing both the NAAQS and the regulations for their implementation. This may sound efficient, but it is not possible in practice; the implementation measures and the NAAQS will have to be drafted at the same time. Because the NAAQS are set before the implementation guidelines, the only way to simultaneously release both the NAAQS and their implementing regulations is to know what the NAAQS will be before they are set. This raises questions about the integrity and legitimacy of the NAAQS process.

The memo also ends the practice of EPA collaboration with other agencies while setting the NAAQS, which reduces the robustness of the process.

None of these significant changes have been offered for public input or accountability.

Numerous other changes by EPA also affect the NAAQS process. For more information, please see our other Mission Tracker posts, including:

This post was edited for clarity on Dec. 10, 2019.

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