Transportation Conformity Guidance for 2012 PM2.5 Non-attainment Areas, EPA-420-B-15-091
Abstract
This document provides guidance for meeting transportation conformity requirements in areas designated non-attainment for the 2012 primary annual PM2.5 national ambient air quality standards (2012 PM2.5 NAAQS). The 2012 PM2.5 NAAQS was established at 12.0 micrograms per cubic meter (µg/m3). EPA’s final rule designating non-attainment areas for the 2012 PM2.5 NAAQS was published in the Federal Register (see 80 FR 2206) on January 15, 2015 and is effective April 15, 2015. This rule established initial air quality designations and classifications for the 2012 PM2.5 NAAQS for most areas in the United States. The guidance is intended to take the information contained in the transportation conformity rule (40 CFR Part 93) and EPA’s existing guidance for implementing conformity in multi-jurisdictional areas and demonstrate how conformity specifically applies in the context of the 2012 PM2.5 NAAQS. The transportation conformity rule is already structured so that existing conformity requirements will apply for any new or revised NAAQS; the conformity rule, therefore, applies directly and does not need to be updated to reflect the 2012 PM2.5 NAAQS.