Deadline Extended for Promulgation of 1-Hour SO2 NAAQS

U.S. EPA announced in Federal Register Vol. 77, No. 150 published on August 3, 2012 that it is using its authority under the Clean Air Act (CAA) to extend by up to one (1) year the deadline for promulgating the initial area designations for the 1-hour sulfur dioxide (SO₂) National Ambient Air Quality Standard (NAAQS).  This will now require U.S. EPA to complete initial designations for the 1-hour SO₂ NAAQS by June 3, 2013.  U.S. EPA cited CAA Section 107(d)(1)(B)(i) which states that “Upon promulgation or revision of a NAAQS the Administrator shall promulgate the designations of all areas (or portions thereof) as expeditiously as practicable, but in no case later than 2 years from the date of promulgation of the new or revised NAAQS.  Such period may be extended for up to 1 year in the event the Administrator has insufficient information to promulgate the designations” for its justification of the extension.  U.S. EPA indicated that based on comments received from the September 2011 Draft SO2 NAAQS Implementation Guidance Document and the subsequent comments received as part of the stakeholder meetings that it remains significantly uncertain what analytical approach sources, States, and U.S. EPA will consistently and cooperatively use to make the determinations required under the CAA to determine attainment status with the 1-hour SO₂ NAAQS.  U.S. EPA further concluded that it currently has insufficient information to promulgate designations by June 2012.  U.S. EPA indicated that it intends to resolve the “issue” of how to determine an area’s attainment status by the end of the year.  However, U.S. EPA gave no indication of whether it will move forward with modeling or monitoring to determine attainment status.  U.S. EPA did indicate that it will move forward with the final designations for areas with monitored violations of the 1-hour SO₂ NAAQS. 

For more information on the history of the promulgation of the 1-hour SO2 NAAQS please refer to ALL4’s June 4TR article “How the SO₂ NAAQS Came Crashing Down On Us.”