SEPA
United States
Environmental Protection
Agency
   Office of Transportation & Air Quality
                EPA-420-B-13-056
                  November 2013
  Transportation Conformity Guidance for Quantitative Hot-spot Analyses in
             PM2.5 and PM10 Nonattainment and Maintenance Areas

                    Guidance Change Bulletin: November 2013
       Part of Guidance
                  Change from 2010 Guidance
                       to 2013 Guidance
     Reason for Change
Section 5: Estimating Project-
Level PM Emissions Using
EMFAC (in California)
                 Revised former EMFAC2007
                 section to reflect EMFAC2011
EPA approved EMFAC2011 for
PM hot-spot analyses (78 FR
14533) and committed to update
the 2010 guidance to reflect the
new model
Section 7.6.1:  Placing Receptors.
Overview
                 Deleted Exhibit 7-4 and
                 reorganized in accordance with
                 revisions to former Sections 7.6.2
                 and 7.6.3 (see below)
In EPA's 2012 PM NAAQS
final rule (78 FR 3264), EPA
committed to review the
guidance and revise as necessary
in accordance with the PM2 5
NAAQS and air quality
monitoring regulatory revisions
Section 7.6.2:  General guidance
for receptors for all PM NAAQS
                 Revised examples for finer and
                 wider receptor spacing to only
                 include outer range; for example
                 "finer spacing (e.g., 10-25
                 meters)" changed to "finer
                 spacing (e.g., 25 meters)"
Reflect latest information from
guidance implementation to date
so that PM hot-spot analyses
include appropriate spacing
while using state and local
resources efficiently
Section 7.6.3:  Additional
Guidance for Receptors for the
PM25NAAQS
                 Deleted
Reflect 2012 PM NAAQS final
rule
Section 9.1-9.3: Calculating PM
Design Values and Determining
Conformity
                 Clarified Exhibit 9-2 and
                 sentences that refer to Section 9.4
                 to be consistent with revised
                 Section 9.4 (see below)
Reflect 2012 PM NAAQS final
rule
Section 9.4: Determining
Appropriate Receptors for
Comparison to the Annual PM2 5
NAAQS
                 Revised in its entirety
Reflect 2012 PM NAAQS final
rule
Appendix G: Example of Using
EMFAC for a Highway Project
                 Revised to reflect use of
                 EMFAC2011
Reflect latest approved EMFAC
model
Appendix H: Example of Using
EMFAC to Develop Emission
Factors for a Transit Project
                 Revised to reflect use of
                 EMFAC2011
Reflect latest approved EMFAC
model

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