Effective Permitting Tools for Fine Particulate Matter under the Prevention of Significant Deterioration Permitting Program
On February 7, 2024, the U.S. Environmental Protection Agency (EPA) strengthened the National Ambient Air Quality Standards (NAAQS) for fine particle pollution (PM2.5) by revising the level of the primary (health-based) annual PM2.5 standard to 9.0 micrograms per cubic meter (µg/m3). On and after the May 6, 2024 effective date of the final rule, any permit issued under the Prevention of Significant Deterioration (PSD) program will need to include, among other things, a demonstration that the proposed emissions would not cause or contribute to a violation of the revised primary annual PM2.5 NAAQS.
Regulations, guidance, and technical tools are available to implement the strengthened primary annual PM2.5 NAAQS under the PSD program. Included on this page is a reference list of policy and technical guidance, models, and tools to assist stakeholders in identifying and accessing these resources as part of a PSD permitting action. EPA staff are available to consult with permit reviewing authorities and individual sources on a case-by-case basis to identify the existing data, models, and tools to demonstrate compliance and, as appropriate, exercise the inherent discretion and flexibilities within the permitting process to best evaluate impacts from a proposed new major source or major modification of an existing source. Air agencies and permit applicants seeking to obtain EPA assistance should contact their appropriate EPA Regional Office.