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EPA Proposes Nonattainment Classifications and Deadlines for SIP Submittals for the 1997 and 2006 PM2.5 NAAQS


As reported in the fourth quarter 2012 issue of the Air Quality Letter, on Jan. 4, 2013, the U.S. Court of Appeals for the District of Columbia Circuit held that EPA’s final rules establishing implementation requirements for the PM2.5 National Ambient Air Quality Standard (NAAQS) were inconsistent with the Clean Air Act. Specifically, the court ruled that EPA’s PM2.5 implementation rules must be based on the particulate matter-specific provisions of Subpart 4 of Part D of Title I of the Act, and not the more general provisions of Subpart 1 of Part D of Title I. As a result, EPA was required to identify and establish classifications for areas designated as nonattainment for the PM2.5 NAAQS. Under Subpart 4 of the Act, Section 188, all areas designated nonattainment are initially classified by operation of law as “moderate” nonattainment areas. Such areas remain classified as moderate nonattainment areas until and unless EPA later classifies them as serious nonattainment areas.

In its Nov. 21, 2013, proposed rule, EPA notes there are only a few areas of the country that remain nonattainment for the 1997 and 2006 PM2.5 NAAQS. They include areas in Montana, California, Alaska and Utah, which are identified in the proposed rule. EPA is proposing to provide these areas until Dec. 31, 2014, to submit updated State Implementation Plans (SIPs) pursuant to Subpart 4 of Part D of Title I of the Act. EPA notes that the Subpart 4 SIP requirements for areas classified as moderate PM2.5 nonattainment areas are generally comparable to those of Subpart 1. Subpart 4 also includes additional statutory SIP planning provisions in the event EPA reclassifies a moderate nonattainment area to serious nonattainment area.

It is important to note that, as discussed elsewhere in this and previous issues of the Air Quality Letter, effective March 18, 2013, EPA also adopted a more stringent primary annual PM2.5 standard of 12 µg/m3.  Several counties in Indiana have 2010-2012 monitoring data in excess of the new standard. Accordingly, such areas would potentially be designated as moderate nonattainment as a result of the Jan. 4, 2013, court ruling.

To view a complete PDF of the Fourth Quarter 2013 issue of the Air Quality Letter, click HERE.

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