EPA Issues Final Final 24-hour PM2.5 Designations

On Oct. 8, EPA made new "final" area designations for the 2006 24-hour PM2.5 NAAQS (based on 2006-2008 data).  The original "final" designations were made in December, 2008 (based on 2005-2007 data), but the new EPA wanted to review them before going final again.  EPA has designated 31 areas as nonattainment (down from 58, after consideration of the 2008 air quality data) and several additional areas as potentially nonattainment based on possible violations.  States that contain areas designated as non-attainment must submit SIPs within three years to describe their plans to achieve attainment, using the SIP requirements for the 1997 PM2.5 NAAQS as a guide, pending any revisions to the requirements.  The rule also lists the designations for nonattainment for the 1997 PM2.5 NAAQS and reiterates that these designations remain in effect until further action.

In the meantime, EPA is in the process of its periodic review of the air quality criteria and NAAQS for airborne PM, as required under Section 109(d) of the CAA.  The CASAC review panel was formed in 2007 and related draft documents were recently published for public review and comment, as noted below.  Currently, EPA is targeting Jan. 2011 and Oct. 2011 for the proposed and final rule respectively establishing new PM NAAQS.