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

Subverting the Process of Setting Health-Based Air Quality Standards: EELP Interviews Janet McCabe

by EELP Staff

The EPA has changed its policy on litigation in ways that make it harder for citizens and courts to hold the agency accountable when it fails to do its job.

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.


The science- and health-based National Ambient Air Quality Standards are the foundation of the progress America has made in cleaning up the air over the past several decades. Thanks to these standards, air quality in almost every US city is far improved over what it was in the 1970s – this is why the air of Los Angeles today no longer resembles the soot- and smog-choked air of cities like Beijing.

Essential to this success is that the process of setting the standards has been exclusively science-based, as both the Clean Air Act requires, and the Supreme Court has confirmed. Considerations of cost are expressly excluded from the science-based assessment of what levels of pollution can be considered “safe” for public health.

Since science itself continues to advance, Congress harnessed progressive improvement in public health protection to the advance of science by requiring EPA to review the standards every five years in light of new scientific developments.

Once new standards are set, the “action-based” provisions of the Clean Air Act are set in motion to reduce air pollution.

Scott Pruitt’s May 9 memo threatens to undermine the integrity of the standard-setting process and to sever the harness linking ongoing improvements in air quality and public health protection to the advance of science by:

  • Introducing non-scientific considerations into science-based assessments, conflating the question of “what is science telling us is safe?” with “how much do we want to spend?”
  • Inverting the purpose of the Clean Air Act reviews, as if meeting deadlines intended to ensure continual science-based assessment is more important than getting the science right
  • Collapsing into one step a two-step sequence that separates health and cost considerations – determining safe air quality levels based on health science and then designing the rules for achieving those levels
  • Via a memo not subject either to public comment or judicial review, unilaterally amending a cardinal provision of the Clean Air Act that excludes cost and other considerations from the science-based assessment of air quality standards

The approach laid out in the May 9 memo, featuring the intrusion of non-science-related considerations in making what should be health-science-based assessments, works in an adverse synergy with changes Pruitt has made to the EPA’s science advisory panels and his proposal to suppress certain critical scientific studies.


On May 9, 2018, Scott Pruitt signed a Memorandum, Back-to-Basics Process for Reviewing National Ambient Air Quality Standards, which makes changes to the process for reviewing and setting National Ambient Air Quality Standards under the Clean Air Act.

Setting National Ambient Air Quality Standards (NAAQS) is the most fundamental task of the EPA under the Clean Air Act. EPA sets standards for six pervasive pollutants that affect public health, called “criteria pollutants.” These pollutants are: carbon monoxide, lead, ground-level ozone, nitrogen dioxide, particulate matter, and sulfur dioxide.

The Clean Air Act requires EPA to review the NAAQS for each of the six criteria pollutants every five years in order to ensure that the agency can revise the standards as new scientific studies demonstrate what levels of these pollutants are harmful to human health. During this review, the EPA can decide to keep existing standards or create revised standards.

Congress intended the Clean Air Act to first and foremost protect human health by establishing these reviews that allow adjustments to pollution limits according to the best available information over time. EPA sets the NAAQS with an adequate margin of safety, considering sensitive populations like children, the elderly, and people with respiratory conditions.

After the NAAQS are set solely according to public health science, then EPA can begin to consider how to achieve the standards from a technology perspective.

The new “Back-to-Basics” process outlined in the memo will collapse the two steps, first considering public health and then considering technology, into one step. According to the May 9 memo, these traditionally separate phases must be combined in order to speed up the process.

There have been changes to this process in the past in order to make it more efficient, but past changes have safeguarded the thoroughness and scientific integrity of the process while streamlining aspects of it.

In the past, groups have attempted to introduce economic and technological considerations into the NAAQS-setting process, which is supposed to only consider health science. The Supreme Court, in Whitman v. American Trucking Associations, Inc., ruled that EPA is not allowed to consider the costs of implementation when setting the NAAQS. Those groups have a voice and influence in how states decide how they will implement the new standards through State Implementation Plans.

The “Back-to-Basics” memo suggests EPA will consider economic effects during the NAAQS review process. The Clean Air Act lists “…adverse public health, welfare, social, economic, or energy effects…” as topics the Clean Air Scientific Advisory Committee can provide advice on, but only for compliance with the NAAQS, not the creation of the NAAQS. That provision relates to EPA drafting the implementing regulations for states, which traditionally happens after the NAAQS are already set. The 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.

The memo ends the practice of EPA collaboration with other agencies while setting the NAAQS. This means that EPA will miss out on valuable insights from other agencies during the process.

The memo also proposes releasing both the NAAQS and the regulations for their implementation at the same time. This may sound like an efficient proposal, but it is practically impossible to achieve because the implementation measures and the NAAQS will have to be drafted at the same time. Normally, the NAAQS are set first and then guidelines for implementation of the standards are written.

The only way to release both the NAAQS and their implementing regulations at the same time is to know what the NAAQS will be before they are set. Being able to release both at the same time raises questions about the integrity and legitimacy of the NAAQS process.

EPA’s proposals regarding science transparency, which we have written about previously, will also affect the NAAQS process by limiting the health science that EPA can consider. The memo itself makes reference to the need to “ensure transparency” in the scientific studies reviewed during the process.

The group of scientists conducting the scientific review for the NAAQS, the Clean Air Scientific Advisory Committee, will differ from past groups due to changes to eligibility requirements for scientists. These changes have resulted in a reduction in professors from research institutions and an increase in scientists employed by industry.

Ultimately, the new process outlined in the memo changes the NAAQS process in significant ways that amount to amendments to the Clean Air Act performed by Administrator Pruitt without any opportunities for public input or accountability.

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