&EPA
United States
Environmental Protection
Agency
   Office of Transportation and Air Quality
                   EPA-420-B-15-090
                    November 2015
   Transportation Conformity Guidance for Quantitative Hot-spot Analyses in Plvh.sand PMio
                           Nonattainment and Maintenance Areas
                         Guidance Change Bulletin: November 2015
 Part of Guidance
                 Change from 2013 Guidance to
                 2015 Guidance
Reason for Change
 Section 1.2: Requirement for
 Quantitative PM Hot-spot
 Analyses	
                 Revised to describe past events
                 instead of occurring events
Section brought up to date
 Section 2.6: NAAQS
 Considered in PM Hot-spot
 Analyses
                 Clarified section and added new
                 footnote to reflect new PM
                 NAAQS
In December 2012, EPA
promulgated a revised annual
primary PM2.5 NAAQS of 12.0
u.g/m3 (80 Federal Register 2206).
Conformity will apply for this
NAAQS on April 15, 2016
 Section 2.8: Appropriate
 Time Frame and Analysis
 Years
                 Added sentence to clarify
                 analysis years must be within
                 the timeframe of the
                 transportation plan/regional
                 emissions analysis, per the
                 regulations
Reflect guidance implementation
and experience in the field
 Section 4: Estimating
 Project-Level PM Emissions
 Using MOVES
                 Revised in its entirety to reflect
                 MOVES2014/MOVES2014a
EPA released MOVES2014 (79
Federal Register 60343); revised
guidance is also applicable to
minor revisions to MOVES2014
model, such as MOVES2014a
 Section?: Selecting an Air
 Quality Model, Data Inputs,
 and Receptors
                 Described area sources before
                 volume sources and noted that
                 area sources may be easier to
                 characterize correctly compared
                 to volume sources
Reflect guidance implementation
and experience in the field
 Section 7.5: Incorporating
 Meteorological Data
                 Added new sentence
                 emphasizing representativeness
                 of meteorological data; added
                 new sentence about processing
                 five years of meteorological data
                 in one AERMOD run
Reflect guidance implementation
and experience in the field
 Section 7.6.2: General
 Guidance for Receptors for
 all PM NAAQS
                 Clarified receptors should be
                 placed in areas considered
                 ambient air, i.e., where the
                 public generally has access.
                 Deleted text that said to exclude
                 areas where public present only
                 for a short period of time, or
                 behind fenced property
Updated to be consistent with
Appendix W and EPA guidance for
receptor placement when
modeling air quality for stationary
sources

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Part of Guidance
Change from 2013 Guidance to
2015 Guidance
Reason for Change
Section 7.7: Running the
Model and Obtaining Results
Added new sentence regarding
AERMOD results
Reflect guidance implementation
Section 8.3.2: Adjusting Air
Quality Monitoring Data to
Account for Future Changes
in Air Quality: Using
Chemical Transport Models
Added new sentences regarding
photochemical modeling
Reflect guidance implementation
Section 9.3.3: 24-hour PM2.5
NAAQS
Revised Tier 1 and Tier 2 design
value calculations for this
NAAQS
Changed to be more consistent
with the way the 24-hour PM2.s
NAAQS design value is calculated
with other EPA Programs,
including EPA's "Guidance for
PM2.s Permit Modeling/' issued
May 20, 2014	
Section 9.3.4: 24-hour
NAAQS
Revised design value calculation
for this NAAQS.  Also ensured
calculation now takes into
account the number of
background concentrations
available
Changed to be more consistent
with the way the PMio NAAQS
design value is calculated for
other EPA programs
Section 10: Mitigation and
Control Measures
Updated web links
Ensure document is current
Appendix A:  Clearinghouse
of Websites, Guidance, and
Other Technical Resources
for PM Hot-spot Analyses
Updated web links and
documents
Ensure document is current
Appendix E:  Example
Quantitative PM Hot-spot
Analysis of a Highway Project
Using MOVES and CAL3QHCR
Removed content but appendix
retained
The example in this appendix has
been superseded by the example
analysis found in EPA's
quantitative PM hot-spot analysis
course, found on the web at
www.epa.gov/otaq/stateresource
s/transconf/training3day.htm
Appendix F: Example
Quantitative PM Hot-spot
Analysis of a Transit Project
Using MOVES and AERMOD
Removed content but appendix
retained
The example in this appendix has
been superseded by the example
analysis found in EPA's
quantitative PM hot-spot analysis
course, found on the web at
www.epa.gov/otaq/stateresource
s/transconf/training3day.htm
AppendixJ.3:  Characterizing
Emission Sources
Described area sources before
volume sources and noted area
sources may be easier to
characterize correctly compared
Reflect guidance implementation
and experience in the field

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Part of Guidance

Appendix J. 6.: Running the
Model and Obtaining Results
Appendix K.4: Example: 24-
hour PM2.5NAAQS
Appendix K.5: Example: 24-
hour PMio NAAQS
Appendix L: Calculating 24-
hour PM2.s Design Value
Using a Tier 2 Approach
Change from 2013 Guidance to
2015 Guidance
to volume sources; included
additional information
Included additional information
for running air quality models
that reflects new design value
calculations specified above in
Section 9.3.3
Revised to reflect new Tier 1
design value calculation
specified above in Section 9.3.3
Revised to reflect new design
value calculation specified
above in Section 9.3.4
Added new appendix to describe
how to calculate the Tier 2
design value approach
Reason for Change

Design value change necessitated
revising instructions
Revised appendix is consistent
with design value used for other
EPA programs
Revised appendix is consistent
with design value used for other
EPA programs
New appendix is consistent with
design value used for other EPA
programs, including EPA's
"Guidance for PM2.5 Permit
Modeling/' issued May 20, 2014

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