Last week, EPA Administrator Scott Pruitt released a Memorandum setting out changes to the process by which EPA reviews and sets National Ambient Air Quality Standards (NAAQS).  The procedural changes—dubbed a “Back to Basics” approach—are intended to “help EPA meet its statutory obligations consistent with [its] commitment to cooperative federalism.” Pruitt’s Memorandum also builds on a White House Memorandum released last month that directs EPA to ensure efficient and cost-effective implementation of the NAAQS program, especially with respect to permitting decisions for the construction of industrial and manufacturing facilities.

Pruitt’s Memorandum directs EPA and the Clean Air Scientific Advisory Committee (CASAC) to adhere to the following principles:

1. Meet Statutory Deadlines. EPA and CASAC are directed to look for opportunities to streamline the NAAQS review process to ensure that new standards are timely set at five-year intervals.
2. Address all Clean Air Act Provisions for NAAQS Reviews.  EPA will provide a standardized set of key questions to CASAC to frame the entirety of the NAAQS review process, including questions designed to elicit information about the health, welfare, social, economic, and energy effects of NAAQS standards.  The Memorandum acknowledges that under Whitman v. American Trucking Associations, Inc., 531 U.S. 457 (2001), EPA may not consider the cost of implementation when reviewing and revising NAAQS.  The Memorandum suggests that the Administrator may still take into account welfare, economic, and energy effects of NAAQS standards, because the Clean Air Act does not require EPA to establish NAAQS at a zero-risk level, but rather at a level that reduces risk to sufficiently protect public health with an adequate margin of safety: “The selection of any particular approach to providing an adequate margin of safety is a policy choice left specifically to the Administrator’s judgment.”
3. Streamline and Standardize the Process for Development and Review of Key Policy-Relevant Information.  EPA’s Integrated Science Assessments, Risk and Exposure Assessments, and Policy Assessments should focus on policy-relevant science and on studies, causal determinations, or analyses that address key questions related to the adequacy of NAAQS.
4. Differentiate Science and Policy Considerations in the NAAQS Review Process.  EPA should establish a clear distinction between the purely scientific findings of the Integrated Science Assessment and the wider range of policy concerns that the Administrator must consider when reviewing NAAQS.
5. Timely Implementation of Regulations and Guidance.  When a NAAQS is revised, EPA should, where appropriate and consistent with law, also provide implementation regulations and guidance as well as technical information to assist state co-regulators in developing approvable plans to implement and maintain the NAAQS.