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Appendix E-2f
Regional Haze Modeling for Southeastern VISTAS II
Regional Haze Analysis Project 2028 Emissions
Version V3 and V5 Comparison Report
Benchmark Run #7
September 22, 2020
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CAMx Benchmarking Report #6 (for Run #7)
Regional Haze Modeling for Southeastern
VISTAS II Regional Haze Analysis Project
2028 Emissions Version V3 and V5 Comparison Report
Task 6 Benchmark Report #6
Covering Benchmark Run #7
Prepared for:
Southeastern States Air Resource Managers, Inc.
(SESARM)
205 Corporate Center Drive, Suite D
Stockbridge, GA 30281-7383
Under Contract No. V-2018-03-01
Prepared by:
Alpine Geophysics, LLC
387 Pollard Mine Road
Burnsville, NC 28714
and
Eastern Research Group, Inc.
1600 Perimeter Park Dr., Suite 200
Morrisville, NC 27560
September 22, 2020
Final
Alpine Project Number: TS-527
ERG Project Number: 4133.00.006
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Contents
Page
1.0 INTRODUCTION ............................................................................................................1
1.1 Overview ...............................................................................................................1
1.2 Emissions Update..................................................................................................3
1.3 2028elv3 and 2028elv5 CAMx 6.40 Comparison ................................................3
2.0 DIFFERENCES BETWEEN 2028ELV3 AND 2028ELV5 SIMULATIONS .................4
3.0 CONFIRMATION METHODOLOGY ............................................................................4
3.1 CAMx Species Mapping .......................................................................................5
4.0 CAMX 2028ELV3 AND 2028ELV5 COMPARISON ....................................................6
4.1 Emissions ..............................................................................................................6
4.2 Annual PM2.5 Design Value ................................................................................24
4.3 24-Hour (Daily) PM2.5 Design Value ..................................................................32
4.4 Scatterplots of Ozone and PM Species Concentrations ......................................39
5.0 CONCLUSIONS.............................................................................................................46
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TABLES
Table 3-1. Species Mapping from CAMx into Aggregated Species ...............................................5
Table 4-1. Comparison of CAMx 6.40 2028elv5 and 2028elv3 Annual Emissions .......................7
Table 4-2. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Annual PM2.5
Design Values (µg/m3) for FRM Monitors in VISTAS States ..........................................25
Table 4-3. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Daily (24-Hour)
PM2.5 Design Values (µg/m3) for FRM Monitors in VISTAS States ................................33
FIGURES
Figure 4-1. Comparison of Elevated NOX Emissions (tpy) for CAMx 2028elv5 and 2028elv3
Simulations ..........................................................................................................................8
Figure 4-2. Comparison of Elevated VOC Emissions (tpy) for CAMx 2028elv5 and 2028elv3
Simulations ..........................................................................................................................9
Figure 4-3. Comparison of Elevated PEC Emissions (tpy) for CAMx 2028elv5 and 2028elv3
Simulations ........................................................................................................................11
Figure 4-4. Comparison of Elevated PNH4 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................12
Figure 4-5. Comparison of Elevated PNO3 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................13
Figure 4-6. Comparison of Elevated POA Emissions (tpy) for CAMx 2028elv5 and 2028elv3
Simulations ........................................................................................................................14
Figure 4-7. Comparison of Elevated PSO4 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................15
Figure 4-8. Comparison of Low Level NOX Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................16
Figure 4-9. Comparison of Low Level VOC Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................17
Figure 4-10. Comparison of Low Level SO2 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................18
Figure 4-11. Comparison of Low Level PEC Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................19
Figure 4-12. Comparison of Low Level PNH4 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................20
Figure 4-13. Comparison of Low Level PNO3 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................21
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Figure 4-14. Comparison of Low Level POA Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................22
Figure 4-15. Comparison of Low Level PSO4 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations.........................................................................................................23
Figure 4-16. Comparison of Annual PM2.5 Design Values (µg/m3) for CAMx 6.40 2028elv5
and 2028elv3 Simulations ..................................................................................................30
Figure 4-17. Scatterplot Comparing Annual Average Predicted PM2.5 Design Values (µg/m3)
at all Monitor Locations for CAMx 6.40 2028elv3 and 2028elv5 Simulations
Performed by VISTAS (Alpine) ........................................................................................31
Figure 4-18. Comparison of Daily PM2.5 Design Values (µg/m3) for CAMx 6.40 2028elv5
and 2028elv3 Simulations ..................................................................................................37
Figure 4-19. Scatterplot Comparing Daily (24-hr) Average Predicted PM2.5 Design Values
(µg/m3) at all Monitor Locations for CAMx 6.40 2028elv3 and 2028elv5 Simulations
Performed by VISTAS (Alpine) ........................................................................................38
Figure 4-20. Scatterplot Comparing 24-hour Average Predicted Ozone Concentrations (ppb)
for All Days at all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine) ....................................................39
Figure 4-21. Scatterplot Comparing 24-hour Average Predicted PM2.5 Concentrations (µg/m3)
for All Days all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine) ....................................................40
Figure 4-22. Scatterplot Comparing 24-hour Average Predicted PM2.5 Concentrations
(µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine); Modified Scale .........................41
Figure 4-23. Scatterplot Comparing 24-hour Average Predicted Sulfate Concentrations
(µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine) ....................................................42
Figure 4-24. Scatterplot Comparing 24-hour Average Predicted Nitrate Concentrations
(µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine) ....................................................43
Figure 4-25. Scatterplot Comparing 24-hour Average Predicted Organic Carbon
Concentrations (µg/m3) for All Days all IMPROVE Monitor Locations for CAMx
6.40 2028elv5 and 2028elv3 Simulations Performed by VISTAS (Alpine) .....................44
Figure 4-26. Scatterplot Comparing 24-hour Average Predicted Organic Carbon
Concentrations (µg/m3) for All Days all IMPROVE Monitor Locations for CAMx
6.40 2028elv5 and 2028elv3 Simulations Performed by VISTAS (Alpine); Modified
Scale ...................................................................................................................................45
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Abbreviations/Acronym List
Alpine Alpine Geophysics, LLC
CAMx Comprehensive Air Quality Model with Extensions
dv Deciview
DV Design Value
EGU Electric Generating Unit
EPA Environmental Protection Agency
ERG Eastern Research Group, Inc.
ERTAC Eastern Regional Technical Advisory Committee
FLM Federal Land Manager
FR Federal Register
IPM Integrated Planning Model
km kilometer
µg/m3 microgram per cubic meter
NAAQS National Ambient Air Quality Standard
NOx Oxides of nitrogen
OAQPS Office of Air Quality Planning and Standards
O3 Ozone
OC Organic carbon
OSAT Ozone Source Apportionment Technology
PSAT Particulate Source Apportionment Technology
PEC Primary elemental carbon
PM Particulate matter
PM2.5 Fine particle; primary particulate matter less than or equal to 2.5 microns
in aerodynamic diameter
PNH4 Particulate ammonium
PNO3 Particulate nitrate
POA Primary Organic Aerosol
PSAT Particulate Source Apportionment Technology
PSO4 Particulate sulfate
R2 Pearson correlation coefficient squared
RADM-AQ Regional Acid Deposition Model – aqueous chemistry
RHR Regional Haze Rule
SESARM Southeastern States Air Resource Managers, Inc.
SIP State Implementation Plan
SMAT-CE Software for Model Attainment Test – Community Edition
SMOKE Sparse Matrix Operator Kernel Emissions
SO2 Sulfur dioxide
SOA Secondary organic aerosol
SOAP Secondary organic aerosol partitioning
tpy Tons per year
U.S. United States
VISTAS Visibility Improvement – State and Tribal Association of the Southeast
VOC Volatile organic compounds
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1.0 INTRODUCTION
1.1 Overview
Southeastern States Air Resource Managers, Inc. (SESARM) has been designated by the
United States (U.S.) Environmental Protection Agency (EPA) as the entity responsible for
coordinating regional haze evaluations for the ten Southeastern states of Alabama, Florida,
Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, and West
Virginia. The Eastern Band of Cherokee Indians and the Knox County, Tennessee local air
pollution control agency are also participating agencies. These parties are collaborating through
the Regional Planning Organization known as Visibility Improvement - State and Tribal
Association of the Southeast (VISTAS) in the technical analyses and planning activities
associated with visibility and related regional air quality issues. VISTAS analyses will support
the VISTAS states in their responsibility to develop, adopt, and implement their State
Implementation Plans (SIPs) for regional haze.
The state and local air pollution control agencies in the Southeast are mandated to protect
human health and the environment from the impacts of air pollutants. They are responsible for
air quality planning and management efforts including the evaluation, development, adoption,
and implementation of strategies controlling and managing all criteria air pollutants including
fine particles and ozone (O3) as well as regional haze. This project will focus on regional haze
and regional haze precursor emissions. Control of regional haze precursor emissions will have
the additional benefit of reducing criteria pollutants as well.
The 1999 Regional Haze Rule (RHR) identified 18 Class I Federal areas (national parks
greater than 6,000 acres and wilderness areas greater than 5,000 acres) in the VISTAS region.
The 1999 RHR required states to define long-term strategies to improve visibility in Federal
Class I national parks and wilderness areas. States were required to establish baseline visibility
conditions for the period 2000-2004, natural visibility conditions in the absence of anthropogenic
influences, and an expected rate of progress to reduce emissions and incrementally improve
visibility to natural conditions by 2064. The original RHR required states to improve visibility on
the 20% most impaired days and protect visibility on the 20% least impaired days.1 The RHR
1 RHR summary data is available at: http://vista.cira.colostate.edu/Improve/rhr-summary-data/
CAMx Benchmarking Report #6 (for Run #7)
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requires states to evaluate progress toward visibility improvement goals every five years and
submit revised SIPs every ten years.
EPA finalized revisions to various requirements of the RHR in January 2017 (82 FR
3078) that were designed to strengthen, streamline, and clarify certain aspects of the agency’s
regional haze program including:
A. Strengthening the Federal Land Manager (FLM) consultation requirements to ensure
that issues and concerns are brought forward early in the planning process.
B. Updating the SIP submittal deadlines for the second planning period from July 31,
2018 to July 31, 2021 to ensure that they align where applicable with other state
obligations under the Clean Air Act. The end date for the second planning period
remains 2028; that is, the focus of state planning will be to establish reasonable
progress goals for each Class I area against which progress will be measured during
the second planning period. This extension will allow states to incorporate planning
for other Federal programs while conducting their regional haze planning. These
other programs include: the Mercury and Air Toxics Standards, the 2010 1-hour
sulfur dioxide (SO2) National Ambient Air Quality Standards (NAAQS); the 2012
annual fine particle (PM2.5) NAAQS; and the 2008 and 2015 ozone NAAQS.
C. Adjusting interim progress report submission deadlines so that second and subsequent
progress reports will be due by: January 31, 2025; July 31, 2033; and every ten years
thereafter. This means that one progress report will be required midway through each
planning period.
D. Removing the requirement for progress reports to take the form of SIP revisions.
States will be required to consult with FLMs and obtain public comment on their
progress reports before submission to the EPA. EPA will be reviewing but not
formally approving or disapproving these progress reports.
The RHR defines “clearest days” as the 20% of monitored days in a calendar year with
the lowest deciview (dv) index values. “Most impaired days” are defined as the 20% of
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monitored days in a calendar year with the highest amounts of anthropogenic visibility
impairment. The long-term strategy and the reasonable progress goals must provide for an
improvement in visibility for the most impaired days since the baseline period and ensure no
degradation in visibility for the clearest days since the baseline period.
1.2 Emissions Update
Since the completion of the original round of emissions inventory development,
emissions processing, modeling, and Particulate Source Apportionment Technology (PSAT),
SESARM concluded that the 2028 point electric generating unit (EGU) and non-EGU emissions
needed to be reviewed and updated for selected sources. These include data review from:
• Point source emissions updates identified in the Area of Influence report;
• Updated EGU emissions developed by the Eastern Regional Technical Advisory
Committee (ERTAC);
• EPA’s 2028 point source emissions based on the 2016 modeling platform; and
• Additional facility emission updates after PSAT analysis.
Specific updates related to development of the 2028 emissions inventory updates are presented in
the Task 2 and Task 3 updated reports.2,3
1.3 2028elv3 and 2028elv5 CAMx 6.40 Comparison
Under subcontract to Eastern Research Group, Inc, (ERG), Alpine Geophysics, LLC
(Alpine) has executed two air quality simulations for the 2028el projection year modeling
platform using CAMx 6.40. We note that CAMx 6.50 has now been released, however that
model release was too late to be included with sufficient certainty in the VISTAS II project
schedule.
This comparison is to document the differences in model estimates between CAMx 6.40
2028elv3 and 2028elv5 as is discussed in the VISTAS II Modeling Protocol.4
2 Southeastern States Air Resource Managers, Inc. "Southeastern VISTAS II Regional Haze Analysis Project - Task 2 and Task
11.3 Emission Inventory Updates Report." Prepared by Eastern Research Group, Inc. under Contract V-2018-03-01. Final.
September 2020.
3 Southeastern States Air Resource Managers, Inc. "Conversion of the Task 2B 2028 Point Source Remodeling Files for
Emissions Processing with SMOKE, Task 3." Prepared by Alpine Geophysics, LLC and Eastern Research Group, Inc. under
Contract V-2018-03-01. Final. September 2020.
4 “Regional Haze Modeling for Southeastern VISTAS II Region Haze Analysis Project, Final Modeling Protocol. Update and
Addendum to the Approved Modeling Protocol for Task 6.1 (June 2018).” Prepared for SESARM under Contract No. V-
2018-03-01. Prepared by Alpine Geophysics, LLC and Eastern Research Group, Inc. August 31, 2020.
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2.0 DIFFERENCES BETWEEN 2028ELV3 AND 2028ELV5
SIMULATIONS
Differences in modeled output concentrations between the 2028elv3 and 2028elv5 CAMx
6.40 simulations were as a result solely of changes to the emissions inventory.
There are notable emissions inventory differences used in the modeling by SESARM
compared to EPA’s 2028el modeling platform. SESARM updated the 2028 emissions inventory
used in this analysis (2028elv5) with changes to both electric generating unit (EGU) and non-
EGU point source emissions. Summaries of the emission differences are presented in the updated
Task 2 and 3 reports2,3 for this study, the Alpine Geophysics memo “Task 6 – Benchmark #7
Review and 2028elv3 Reassessment” (Appendix A), and summarized in Section 4.1.
The VISTAS emissions processing was restricted to 2011, however, the CAMx model
has a “spin-up” period from December 22 through December 31, 2010 to minimize the influence
of the global model-derived initial conditions. For the 2028elv3 simulation the spin-up period for
the low level emissions were based on the EPA supplied 2028el emissions for the December
2010 period. The elevated 2028elv3 emissions and the 2028elv5 low level and elevated
emissions were copied by day of week from the beginning of 2011. This small difference in
emissions handling led to differences in model concentrations during January 1-2, 2011. January
1-2 do not represent any 20% clearest or 20% most anthropogenically impaired days at any Class
I area and therefore our results here do not include these days in the 2028elv3 and 2028elv5
modeled value scatterplots.
3.0 CONFIRMATION METHODOLOGY
The presented comparison of model simulations are based on annual and 24-hour PM2.5
design values as generated from the output of the two VISTAS12-based simulations; CAMx 6.40
with 2028elv3 and 2028elv5 emissions. This report does not compare hourly concentrations for
each PM species as the model version, platform configuration and processing methods, and the
underlying projection year emissions inventories differ significantly between the two model runs
making it difficult, if not impossible, to determine the cause of any differences seen in
concentrations. We also provide a comparison of gridded 12-kilometer (km) annual elevated and
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low level emissions for the domain. The metric for comparison of the design values are the
absolute difference (Equation 1) and percent difference (Equation 2) defined as:
(Equation 1) (𝐶𝐶2028𝑒𝑒𝑒𝑒𝑒𝑒5 −𝐶𝐶2028𝑒𝑒𝑒𝑒𝑒𝑒3 )
(Equation 2) (𝐶𝐶2028𝑒𝑒𝑒𝑒𝑒𝑒5 −𝐶𝐶2028𝑒𝑒𝑒𝑒𝑒𝑒3)(𝐶𝐶2028𝑒𝑒𝑒𝑒𝑒𝑒3)
Where C2028elv5 is the design value at each FRM monitor for the CAMx simulation with
the 2028elv5 emissions and C2028elv3 is the design value at each FRM monitor for the CAMx
simulation with the 2028elv3 emissions. For the emission comparison plots, only Equation 1
results were calculated for each grid cell and plotted for review.
The results are presented for each FRM monitor in the VISTAS states for each of the two
design values. Emission density spatial maps are presented for only the nested VISTAS12
modeling domain that was reprocessed with updated emissions. On each spatial emissions
difference plot presented, the maximum positive and negative values, along with the grid cell in
which these occur, are presented at the top of the graphic. The coordinates refer to the row and
columns of the cell referenced to the cell coordinates on the bottom (column) and left (row) of
the graphic.
Scatterplots of the daily average concentrations of ozone and the various calculated PM
species in local standard time at the Interagency Monitoring for Protected Visual Environment
(IMPROVE) monitors across all modeled days are also presented with the CAMx 2028elv5
results plotted on the x-axis and the CAMx 2028elv3 results plotted on the y-axis.
3.1 CAMx Species Mapping
The CAMx species mapping from version 6.40 of the model is presented in Table 3-1.
Table 3-1. Species Mapping from CAMx into Aggregated Species
Aggregated Species CAMx 6.40 Species
Ozone O3
PM2.5 PSO4+PNO3+PNH4+SOA1+SOA2+SOA3+SOA4+SOPA+SOPB+POA+PEC
+FPRM+FCRS+NA+PCL
Sulfate PSO4
Nitrate PNO3
Organic Matter (OM) SOA1+SOA2+SOA3+SOA4+SOPA+SOPB+POA
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4.0 CAMX 2028ELV3 AND 2028ELV5 COMPARISON
This section presents comparisons of the simulations using CAMx 2028elv3 and CAMx
2028elv5 performed on the Alpine computer system. Emissions presented are the post-processed
results of the Sparse Matrix Operator Kernel Emissions (SMOKE) emissions tool, including
oxides of nitrogen (NOX), volatile organic compounds (VOC), and speciated PM2.5 components
(e.g., particulate nitrate (PNO3), particulate sulfate (PSO4), etc.) for elevated and low level
sources. Annual and 24-Hour PM2.5 design values are the result of running each of the model
platforms through the Software for the Modeled Attainment Test - Community Edition (SMAT-
CE) tool to generate receptor-level values.
4.1 Emissions
Annual emission summaries have been prepared from the model-ready input files for
both elevated and low level sources. Elevated sources include all CEM-based emissions in the
modeling platform, non-EGU point sources with explicit latitude and longitude release
coordinates and calculated plume rise greater than or equal to twenty (20) meters, emissions
from wildfires, and international commercial marine emissions not otherwise associated with
specific U.S. states. Low-level sources are comprised of all other anthropogenic source types
including non-EGU point sources with a calculated plume rise of less than twenty (20) meters,
agricultural and prescribed fires, biogenic and other natural source emissions, and commercial
marine emissions associated with sources assigned to specific U.S. states. Results presented
include maps of the VISTAS12 domain with annual emissions (tons per year) and emission
differences by grid cell and pollutant. Table 4-1 presents summary results by pollutant over the
VISTAS12 domain for elevated and low level comparisons. Figures 4-1 through 4-7 present the
annual emissions and emission differences for elevated sources by pollutant in the VISTAS12
modeling domain. Figures 4-8 through 4-15 present annual emissions and emission differences
for low level sources, by pollutant, in the VISTAS12 modeling domain.
As expected with the changes in modeled emission inventories between the SESARM
2028elv3 and 2028elv5 platforms, we see the changes in elevated (point source) emissions fairly
uniformly throughout of the modeling domain. Low-level emission changes are also seen
predominantly in the VISTAS states for areas where emission inventory modifications were
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applied for this analysis with scattered changes elsewhere due to the replacement of first-layer
emitting point sources as noted above.
Table 4-1. Comparison of CAMx 6.40 2028elv5 and 2028elv3 Annual Emissions
Source Type Pollutant
2028 Annual Emissions (tons)
2028elv5 Elv5-elv3e Domain Wide Individual Grid Cell
Total Tons Total Change % Change Max Increase Max Decrease
Elevated NOXa 3,303,000 -364,300 -11.03% 8,106 -17,730
Elevated VOCb 3,293,000 -8,109 -0.25% 1,194 -2,331
Elevated SO2c 2,737,000 -918,000 -33.54% 7,247 -53,910
Elevated PEC 183,300 -4,977 -2.72% 140 -290
Elevated PNH4d 9,808 -208 -2.12% 6 -15
Elevated PNO3 11,760 -179 -1.52% 22 -16
Elevated POA 1,208,000 -5,856 -0.48% 180 -406
Elevated PSO4 62,220 -6,059 -9.74% 165 -445
Low Level NOX 5,805,000 -759 -0.01% 61 -157
Low Level VOC 46,160,000 -6,035 -0.01% 1,147 -1,201
Low Level SO2c 257,300 2,321 0.90% 2,849 -157
Low Level PEC 118,400 -52 -0.04% 2 -13
Low Level PNH4b 5,831 -1 -0.02% 0 -1
Low Level PNO3 3,770 -7 -0.17% 0 -1
Low Level POA 757,200 -142 -0.02% 2 -36
Low Level PSO4 150,000 -217 -0.14% 15 -69
a NOX is calculated as the sum of NO plus NO2
b VOC emissions are approximate since calculated from CB6 speciated emissions.
c The molecular weight for SO2 in these totals was 3% higher than the true molecular weight.
d PNH4 = Particulate ammonium
e Emission differences are discussed in the updated Task 2 and 3 reports2,3 for this study and the
Alpine Geophysics memo “Task 6 – Benchmark #7 Review and 2028elv3 Reassessment”
(Appendix A).
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Annual NOX Emissions – Elevated Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-1. Comparison of Elevated NOX Emissions (tpy) for CAMx 2028elv5 and 2028elv3
Simulations
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Annual VOC Emissions – Elevated Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-2. Comparison of Elevated VOC Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
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Annual SO2 Emissions – Elevated Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-3. Comparison of Elevated SO2 Emissions (tpy) for CAMx 2028elv5 and 2028elv3
Simulations
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Annual PEC Emissions – Elevated Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-3. Comparison of Elevated PEC Emissions (tpy) for CAMx 2028elv5 and 2028elv3
Simulations
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Annual PNH4 Emissions – Elevated Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-4. Comparison of Elevated PNH4 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
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Annual PNO3 Emissions – Elevated Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-5. Comparison of Elevated PNO3 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
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Annual POA Emissions – Elevated Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-6. Comparison of Elevated POA Emissions (tpy) for CAMx 2028elv5 and 2028elv3
Simulations
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Annual PSO4 Emissions – Elevated Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-7. Comparison of Elevated PSO4 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
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Annual NOX Emissions – Low Level Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-8. Comparison of Low Level NOX Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
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Annual VOC Emissions – Low Level Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-9. Comparison of Low Level VOC Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
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Annual SO2 Emissions – Low Level Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-10. Comparison of Low Level SO2 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 19
Annual PEC Emissions – Low Level Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-11. Comparison of Low Level PEC Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 20
Annual PNH4 Emissions – Low Level Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-12. Comparison of Low Level PNH4 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 21
Annual PNO3 Emissions – Low Level Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-13. Comparison of Low Level PNO3 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 22
Annual POA Emissions – Low Level Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-14. Comparison of Low Level POA Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 23
Annual PSO4 Emissions – Low Level Sources
2028elv5
Difference (2028elv5 – 2028elv3)
Figure 4-15. Comparison of Low Level PSO4 Emissions (tpy) for CAMx 2028elv5 and
2028elv3 Simulations
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 24
4.2 Annual PM2.5 Design Value
Annual PM2.5 design values were generated using the results of each individual CAMx
simulation (version 6.40 with SESARM’s 2028elv5 and modeled 2028elv3 emissions platforms)
and the SMAT-CE tool. Results for each individual FRM monitor in the VISTAS states are
presented in tabular format in Table 4-2 along with the absolute difference and percent difference
in design value.
The maximum calculated decrease is 0.67 µg/m3 at monitor 211010014 in Henderson,
Kentucky (7% decrease between 2028elv3 and 2028elv5). No increases are calculated at any
FRM monitor in the VISTAS states because of the move from 2028elv3 to 2028elv5. The
average change in annual design value for all monitors in the VISTAS states is a decrease of 0.33
µg/m3, with an average annual percent decrease of 4% at these same locations.
Geographic distribution of the 2028elv5 annual PM2.5 design values and differences in
design values compared to the modeled 2028elv3 simulation are presented in Figure 4-16. In the
VISTAS12 domain, the largest annual PM2.5 design value decreases are seen in areas consistent
with the largest reduction in SO2 and NOX emissions between modeled 2028elv3 and 2020elv5.
The smallest changes are seen on the boundaries of the VISTAS12 domain, consistent with not
reprocessing the larger 12US2 region.
A scatterplot of the annual PM2.5 design values for all FRM monitors in the VISTAS12
domain is presented in Figure 4-17. The CAMx 6.40 2028elv5 results are plotted on the x-axis
and the 2028elv3 results are plotted on the y-axis. The data have a line of best fit with a slope of
1.0277, an intercept of 0.1346 µg/m3and an R2 of 0.9948. As expected, due to the lower
emissions associated with the 2028elv5 platform compared to modeled 2028elv3, new 2028elv5
annual PM2.5 design values are lower at all monitors across all concentration ranges.
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 25
Table 4-2. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Annual PM2.5
Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Annual PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
010030010 Alabama Baldwin 8.06 7.73 -0.33 -4%
010270001 Alabama Clay 7.92 7.59 -0.33 -4%
010331002 Alabama Colbert 8.37 8.03 -0.34 -4%
010491003 Alabama DeKalb 8.52 8.21 -0.31 -4%
010550010 Alabama Etowah 8.84 8.55 -0.29 -3%
010690003 Alabama Houston 8.25 7.98 -0.27 -3%
010730023 Alabama Jefferson 11.17 10.55 -0.62 -6%
010731005 Alabama Jefferson 9.33 8.89 -0.44 -5%
010731009 Alabama Jefferson 8.24 7.80 -0.44 -5%
010731010 Alabama Jefferson 9.56 9.18 -0.38 -4%
010732003 Alabama Jefferson 10.31 9.68 -0.63 -6%
010732006 Alabama Jefferson 9.50 8.96 -0.54 -6%
010735002 Alabama Jefferson 8.97 8.59 -0.38 -4%
010735003 Alabama Jefferson 8.68 8.22 -0.46 -5%
010890014 Alabama Madison 9.15 8.84 -0.31 -3%
010970003 Alabama Mobile 8.17 7.80 -0.37 -5%
010972005 Alabama Mobile 7.83 7.50 -0.33 -4%
011011002 Alabama Montgomery 9.58 9.26 -0.32 -3%
011030011 Alabama Morgan 8.73 8.40 -0.33 -4%
011130001 Alabama Russell 10.17 9.86 -0.31 -3%
011170006 Alabama Shelby 8.18 7.79 -0.39 -5%
011210002 Alabama Talladega 9.14 8.77 -0.37 -4%
011250004 Alabama Tuscaloosa 8.74 8.36 -0.38 -4%
011270002 Alabama Walker 9.12 8.68 -0.44 -5%
120990008 Florida Palm Beach 6.94 6.85 -0.09 -1%
120990009 Florida Palm Beach 5.85 5.73 -0.12 -2%
130210007 Georgia Bibb 10.60 10.32 -0.28 -3%
130210012 Georgia Bibb 7.96 7.69 -0.27 -3%
130510091 Georgia Chatham 8.54 8.31 -0.23 -3%
130590002 Georgia Clarke 8.13 7.81 -0.32 -4%
130630091 Georgia Clayton 9.43 9.11 -0.32 -3%
130670004 Georgia Cobb 8.73 8.39 -0.34 -4%
130890002 Georgia DeKalb 8.76 8.44 -0.32 -4%
130950007 Georgia Dougherty 10.41 10.14 -0.27 -3%
131150003 Georgia Floyd 9.48 9.13 -0.35 -4%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 26
Table 4-2. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Annual PM2.5
Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Annual PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
131210039 Georgia Fulton 10.36 10.02 -0.34 -3%
131390003 Georgia Hall 8.07 7.76 -0.31 -4%
131530001 Georgia Houston 8.55 8.28 -0.27 -3%
132150001 Georgia Muscogee 10.78 10.47 -0.31 -3%
132450005 Georgia Richmond 9.27 9.01 -0.26 -3%
132450091 Georgia Richmond 9.54 9.28 -0.26 -3%
132950002 Georgia Walker 8.02 7.69 -0.33 -4%
133190001 Georgia Wilkinson 9.97 9.71 -0.26 -3%
210130002 Kentucky Bell 8.80 8.45 -0.35 -4%
210190017 Kentucky Boyd 8.31 7.96 -0.35 -4%
210290006 Kentucky Bullitt 9.32 8.83 -0.49 -5%
210373002 Kentucky Campbell 7.61 7.20 -0.41 -5%
210430500 Kentucky Carter 6.80 6.46 -0.34 -5%
210470006 Kentucky Christian 8.39 7.91 -0.48 -6%
210590005 Kentucky Daviess 9.25 8.64 -0.61 -7%
210670012 Kentucky Fayette 7.97 7.52 -0.45 -6%
210930006 Kentucky Hardin 8.4 7.90 -0.50 -6%
211010014 Kentucky Henderson 8.96 8.29 -0.67 -7%
211110067 Kentucky Jefferson 9.44 8.98 -0.46 -5%
211451004 Kentucky McCracken 8.84 8.32 -0.52 -6%
211510003 Kentucky Madison 6.97 6.54 -0.43 -6%
211950002 Kentucky Pike 8.03 7.69 -0.34 -4%
212270008 Kentucky Warren 8.83 8.40 -0.43 -5%
280330002 Mississippi DeSoto 8.36 7.98 -0.38 -5%
280350004 Mississippi Forrest 9.92 9.51 -0.41 -4%
280430001 Mississippi Grenada 8.00 7.62 -0.38 -5%
280450003 Mississippi Hancock 8.23 7.93 -0.30 -4%
280470008 Mississippi Harrison 7.99 7.69 -0.30 -4%
280490010 Mississippi Hinds 9.58 9.21 -0.37 -4%
280590006 Mississippi Jackson 7.90 7.51 -0.39 -5%
280670002 Mississippi Jones 10.1 9.71 -0.39 -4%
280750003 Mississippi Lauderdale 9.20 8.79 -0.41 -4%
280810005 Mississippi Lee 9.36 9.00 -0.36 -4%
370010002 North Carolina Alamance 7.36 7.03 -0.33 -4%
370210034 North Carolina Buncombe 6.97 6.65 -0.32 -5%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 27
Table 4-2. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Annual PM2.5
Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Annual PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
370330001 North Carolina Caswell 6.57 6.23 -0.34 -5%
370350004 North Carolina Catawba 7.98 7.67 -0.31 -4%
370370004 North Carolina Chatham 6.07 5.74 -0.33 -5%
370510009 North Carolina Cumberland 7.66 7.37 -0.29 -4%
370570002 North Carolina Davidson 8.54 8.23 -0.31 -4%
370610002 North Carolina Duplin 6.48 6.21 -0.27 -4%
370630015 North Carolina Durham 7.00 6.67 -0.33 -5%
370650004 North Carolina Edgecombe 6.66 6.35 -0.31 -5%
370670022 North Carolina Forsyth 7.33 6.97 -0.36 -5%
370670030 North Carolina Forsyth 7.34 6.99 -0.35 -5%
370710016 North Carolina Gaston 7.78 7.49 -0.29 -4%
370810013 North Carolina Guilford 6.97 6.62 -0.35 -5%
370810014 North Carolina Guilford 7.14 6.78 -0.36 -5%
370870012 North Carolina Haywood 7.86 7.59 -0.27 -3%
370990006 North Carolina Jackson 7.15 6.87 -0.28 -4%
371010002 North Carolina Johnston 6.70 6.40 -0.30 -4%
371070004 North Carolina Lenoir 6.85 6.57 -0.28 -4%
371110004 North Carolina McDowell 7.60 7.30 -0.30 -4%
371170001 North Carolina Martin 6.39 6.08 -0.31 -5%
371190041 North Carolina Mecklenburg 8.11 7.82 -0.29 -4%
371190042 North Carolina Mecklenburg 8.45 8.17 -0.28 -3%
371190043 North Carolina Mecklenburg 7.64 7.34 -0.30 -4%
371210001 North Carolina Mitchell 7.19 6.91 -0.28 -4%
371230001 North Carolina Montgomery 6.95 6.66 -0.29 -4%
371290002 North Carolina New Hanover 5.61 5.37 -0.24 -4%
371470006 North Carolina Pitt 6.29 6.00 -0.29 -5%
371550005 North Carolina Robeson 7.51 7.23 -0.28 -4%
371590021 North Carolina Rowan 7.85 7.55 -0.30 -4%
371730002 North Carolina Swain 7.50 7.21 -0.29 -4%
371830014 North Carolina Wake 7.89 7.58 -0.31 -4%
371830020 North Carolina Wake 7.09 6.78 -0.31 -4%
371890003 North Carolina Watauga 6.29 5.99 -0.30 -5%
371910005 North Carolina Wayne 7.40 7.16 -0.24 -3%
450190048 South Carolina Charleston 7.11 6.88 -0.23 -3%
450190049 South Carolina Charleston 6.88 6.64 -0.24 -3%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 28
Table 4-2. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Annual PM2.5
Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Annual PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
450250001 South Carolina Chesterfield 7.69 7.41 -0.28 -4%
450370001 South Carolina Edgefield 8.03 7.76 -0.27 -3%
450410003 South Carolina Florence 8.65 8.36 -0.29 -3%
450450009 South Carolina Greenville 8.65 8.31 -0.34 -4%
450450015 South Carolina Greenville 8.92 8.58 -0.34 -4%
450630008 South Carolina Lexington 8.64 8.40 -0.24 -3%
450830011 South Carolina Spartanburg 8.47 8.16 -0.31 -4%
470650031 Tennessee Hamilton 8.55 8.20 -0.35 -4%
470651011 Tennessee Hamilton 8.45 8.08 -0.37 -4%
470654002 Tennessee Hamilton 8.30 7.92 -0.38 -5%
510030001 Virginia Albemarle 6.67 6.34 -0.33 -5%
510360002 Virginia Charles 6.57 6.24 -0.33 -5%
510410003 Virginia Chesterfield 7.44 7.08 -0.36 -5%
510590030 Virginia Fairfax 7.38 6.99 -0.39 -5%
510690010 Virginia Frederick 8.19 7.78 -0.41 -5%
510870014 Virginia Henrico 7.17 6.83 -0.34 -5%
510870015 Virginia Henrico 6.76 6.41 -0.35 -5%
511071005 Virginia Loudoun 7.57 7.20 -0.37 -5%
511390004 Virginia Page 7.13 6.77 -0.36 -5%
511650003 Virginia Rockingham 7.89 7.55 -0.34 -4%
515200006 Virginia Bristol City 7.73 7.45 -0.28 -4%
516500008 Virginia Hampton City 5.93 5.64 -0.29 -5%
516800015 Virginia Lynchburg City 6.52 6.18 -0.34 -5%
517100024 Virginia Norfolk City 7.04 6.75 -0.29 -4%
517700015 Virginia Roanoke City 7.73 7.38 -0.35 -5%
517750011 Virginia Salem City 7.50 7.15 -0.35 -5%
518100008 Virginia Virginia Beach
City
6.98 6.70 -0.28 -4%
540030003 West Virginia Berkeley 9.38 8.96 -0.42 -4%
540090005 West Virginia Brooke 9.59 9.08 -0.51 -5%
540110006 West Virginia Cabell 9.10 8.74 -0.36 -4%
540291004 West Virginia Hancock 8.73 8.23 -0.50 -6%
540390010 West Virginia Kanawha 8.14 7.72 -0.42 -5%
540391005 West Virginia Kanawha 9.27 8.83 -0.44 -5%
540490006 West Virginia Marion 9.21 8.81 -0.40 -4%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 29
Table 4-2. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Annual PM2.5
Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Annual PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
540511002 West Virginia Marshall 10.03 9.58 -0.45 -4%
540610003 West Virginia Monongalia 8.08 7.64 -0.44 -5%
540690010 West Virginia Ohio 8.72 8.22 -0.50 -6%
540810002 West Virginia Raleigh 6.99 6.61 -0.38 -5%
541071002 West Virginia Wood 9.12 8.73 -0.39 -4%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 30
Annual PM2.5 Design Value – VISTAS12 Domain
CAMx 6.40 2028elv5
Annual PM2.5 Design Value Reduction (2028elv3 – 2028elv5)
Figure 4-16. Comparison of Annual PM2.5 Design Values (µg/m3) for CAMx 6.40 2028elv5
and 2028elv3 Simulations
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 31
Figure 4-17. Scatterplot Comparing Annual Average Predicted PM2.5 Design Values
(µg/m3) at all Monitor Locations for CAMx 6.40 2028elv3 and 2028elv5 Simulations
Performed by VISTAS (Alpine)
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 32
4.3 24-Hour (Daily) PM2.5 Design Value
Daily PM2.5 design values were generated using the results of each individual CAMx
simulation (version 6.40 with SESARM’s 2028 elv5 and modeled 2028elv3 emissions platform)
and the SMAT-CE tool. Results for each individual FRM monitor in the VISTAS states are
presented in tabular format in Table 4-3 along with the absolute difference and percent difference
in design value.
The maximum calculated decrease is 2.4 µg/m3 at monitor 010732003 in Jefferson,
Alabama (11% decrease going from 2028elv3 to 2028elv5). No increases are calculated at any
FRM monitor in the VISTAS states because of the move from 2028elv3 to 2028elv5. The
average change in annual design value for all monitors in the VISTAS states is a decrease of 0.7
µg/m3, with an average annual percent decrease of 4% at these same locations.
Geographic distribution of the 6.40 2028elv5 daily PM2.5 design values and reductions in
design values compared to the modeled 2028elv3 simulation are presented in Figure 4-18. Daily
PM2.5 design values have widespread change throughout the VISTAS12 modeling domain with
the smallest daily design value changes seen along the western border of the region.
A scatterplot of the daily PM2.5 design values for all FRM monitors in the VISTAS12
domain is presented in Figure 4-19. The CAMx 6.40 2028elv5 results are plotted on the x-axis
and the modeled 2028elv3 results are plotted on the y-axis. The data has a slope of 0.9977, an
intercept of 0.688 µg/m3 and an R2 of 0.9854. 2028elv5 concentrations are lower compared to
modeled 2028elv3 across all concentration ranges which is consistent with the change in
emissions between the two platforms.
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 33
Table 4-3. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Daily (24-Hour)
PM2.5 Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Daily (24-Hr) PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
10030010 Alabama Baldwin 15.9 15.3 -0.6 -4%
10270001 Alabama Clay 17.2 16.6 -0.6 -3%
10331002 Alabama Colbert 16.2 15.7 -0.5 -3%
10491003 Alabama DeKalb 17.1 16.5 -0.6 -4%
10550010 Alabama Etowah 17.7 17.3 -0.4 -2%
10690003 Alabama Houston 17.0 16.7 -0.3 -2%
10730023 Alabama Jefferson 22.9 22.3 -0.6 -3%
10731005 Alabama Jefferson 17.8 16.9 -0.9 -5%
10731009 Alabama Jefferson 17.8 16.9 -0.9 -5%
10731010 Alabama Jefferson 18.3 17.7 -0.6 -3%
10732003 Alabama Jefferson 21.2 18.8 -2.4 -11%
10732006 Alabama Jefferson 18.6 17.9 -0.7 -4%
10735002 Alabama Jefferson 17.4 16.7 -0.7 -4%
10735003 Alabama Jefferson 17.7 16.9 -0.8 -5%
10890014 Alabama Madison 18.6 18.1 -0.5 -3%
10970003 Alabama Mobile 16.1 15.5 -0.6 -4%
10972005 Alabama Mobile 16.7 16.0 -0.7 -4%
11011002 Alabama Montgomery 19.9 19.4 -0.5 -3%
11030011 Alabama Morgan 16.5 15.8 -0.7 -4%
11130001 Alabama Russell 23.4 23.0 -0.4 -2%
11170006 Alabama Shelby 15.8 15.1 -0.7 -4%
11210002 Alabama Talladega 18.5 18.0 -0.5 -3%
11250004 Alabama Tuscaloosa 19.0 18.4 -0.6 -3%
11270002 Alabama Walker 17.8 17.0 -0.8 -4%
120990008 Florida Palm Beach 15.7 15.5 -0.2 -1%
120990009 Florida Palm Beach 13.6 13.4 -0.2 -1%
130210007 Georgia Bibb 22.1 21.6 -0.5 -2%
130210012 Georgia Bibb 17.9 17.5 -0.4 -2%
130510017 Georgia Chatham 24.3 23.7 -0.6 -2%
130510091 Georgia Chatham 24.4 23.8 -0.6 -2%
130590002 Georgia Clarke 17.6 17.1 -0.5 -3%
130670004 Georgia Cobb 17.1 16.5 -0.6 -4%
130890002 Georgia DeKalb 17.2 16.7 -0.5 -3%
130950007 Georgia Dougherty 24.3 24.0 -0.3 -1%
131390003 Georgia Hall 16.5 15.9 -0.6 -4%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 34
Table 4-3. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Daily (24-Hour)
PM2.5 Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Daily (24-Hr) PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
131530001 Georgia Houston 19.5 19.1 -0.4 -2%
132950002 Georgia Walker 17.2 16.8 -0.4 -2%
133190001 Georgia Wilkinson 20.2 19.8 -0.4 -2%
210130002 Kentucky Bell 20.6 20.2 -0.4 -2%
210190017 Kentucky Boyd 17.8 17.1 -0.7 -4%
210373002 Kentucky Campbell 16.0 15.1 -0.9 -6%
210430500 Kentucky Carter 14.9 14.3 -0.6 -4%
210470006 Kentucky Christian 15.8 14.7 -1.1 -7%
210590005 Kentucky Daviess 19.9 18.3 -1.6 -8%
210670012 Kentucky Fayette 16.2 15.3 -0.9 -6%
210930006 Kentucky Hardin 17.0 16.1 -0.9 -5%
211010014 Kentucky Henderson 18.5 16.7 -1.8 -10%
211110067 Kentucky Jefferson 20.4 19.4 -1.0 -5%
211451004 Kentucky McCracken 17.0 15.8 -1.2 -7%
211510003 Kentucky Madison 14.3 13.5 -0.8 -6%
211950002 Kentucky Pike 18.1 17.4 -0.7 -4%
212270008 Kentucky Warren 16.3 15.3 -1.0 -6%
280330002 Mississippi DeSoto 15.9 15.2 -0.7 -4%
280350004 Mississippi Forrest 19.5 19.0 -0.5 -3%
280430001 Mississippi Grenada 15.8 14.9 -0.9 -6%
280450003 Mississippi Hancock 18.3 17.9 -0.4 -2%
280470008 Mississippi Harrison 15.1 14.8 -0.3 -2%
280490010 Mississippi Hinds 18.5 17.9 -0.6 -3%
280590006 Mississippi Jackson 17.6 16.9 -0.7 -4%
280670002 Mississippi Jones 20.3 19.8 -0.5 -2%
280750003 Mississippi Lauderdale 18.6 17.9 -0.7 -4%
280810005 Mississippi Lee 17.4 16.6 -0.8 -5%
370010002 North Carolina Alamance 15.2 14.6 -0.6 -4%
370210034 North Carolina Buncombe 13.5 12.9 -0.6 -4%
370330001 North Carolina Caswell 12.8 12.4 -0.4 -3%
370350004 North Carolina Catawba 16.4 16.1 -0.3 -2%
370370004 North Carolina Chatham 13.0 12.3 -0.7 -5%
370510009 North Carolina Cumberland 17.0 16.6 -0.4 -2%
370570002 North Carolina Davidson 15.9 15.5 -0.4 -3%
370610002 North Carolina Duplin 14.4 14.0 -0.4 -3%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 35
Table 4-3. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Daily (24-Hour)
PM2.5 Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Daily (24-Hr) PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
370630015 North Carolina Durham 13.9 13.5 -0.4 -3%
370650004 North Carolina Edgecombe 14.7 14.1 -0.6 -4%
370670022 North Carolina Forsyth 15.3 14.8 -0.5 -3%
370670030 North Carolina Forsyth 14.8 14.5 -0.3 -2%
370710016 North Carolina Gaston 16.4 15.8 -0.6 -4%
370810013 North Carolina Guilford 16.1 15.6 -0.5 -3%
370810014 North Carolina Guilford 14.4 13.9 -0.5 -3%
370870012 North Carolina Haywood 18.8 18.4 -0.4 -2%
370990006 North Carolina Jackson 13.8 13.4 -0.4 -3%
371010002 North Carolina Johnston 14.1 13.6 -0.5 -4%
371070004 North Carolina Lenoir 15.8 15.0 -0.8 -5%
371110004 North Carolina McDowell 15.4 14.9 -0.5 -3%
371170001 North Carolina Martin 17.3 16.3 -1.0 -6%
371190041 North Carolina Mecklenburg 17.5 17.0 -0.5 -3%
371190042 North Carolina Mecklenburg 17.9 17.4 -0.5 -3%
371190043 North Carolina Mecklenburg 15.2 14.8 -0.4 -3%
371210001 North Carolina Mitchell 13.8 13.3 -0.5 -4%
371230001 North Carolina Montgomery 14.9 14.4 -0.5 -3%
371290002 North Carolina New Hanover 15.9 15.2 -0.7 -4%
371470006 North Carolina Pitt 15.4 14.8 -0.6 -4%
371550005 North Carolina Robeson 16.9 16.3 -0.6 -4%
371590021 North Carolina Rowan 15.3 14.9 -0.4 -3%
371730002 North Carolina Swain 15.6 15.0 -0.6 -4%
371830014 North Carolina Wake 17.4 16.8 -0.6 -3%
371830020 North Carolina Wake 14.4 13.9 -0.5 -3%
371890003 North Carolina Watauga 13.0 12.5 -0.5 -4%
371910005 North Carolina Wayne 15.8 15.4 -0.4 -3%
450190048 South Carolina Charleston 16.3 15.8 -0.5 -3%
450190049 South Carolina Charleston 15.9 15.3 -0.6 -4%
450250001 South Carolina Chesterfield 15.5 15.1 -0.4 -3%
450370001 South Carolina Edgefield 16.9 16.3 -0.6 -4%
450410003 South Carolina Florence 18.4 18.0 -0.4 -2%
450450009 South Carolina Greenville 18.1 17.6 -0.5 -3%
450450015 South Carolina Greenville 19.3 19.0 -0.3 -2%
450630008 South Carolina Lexington 19.0 18.6 -0.4 -2%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 36
Table 4-3. Comparison of CAMx 6.40 2028elv3 and 2028elv5 Predicted Daily (24-Hour)
PM2.5 Design Values (µg/m3) for FRM Monitors in VISTAS States
Monitor State County
2028 Daily (24-Hr) PM2.5 Design Value (µg/m3)
2028elv3 2028elv5 Difference Percent
Difference
450790019 South Carolina Richland 19.4 18.9 -0.5 -3%
450830011 South Carolina Spartanburg 17.4 16.8 -0.6 -3%
470650031 Tennessee Hamilton 18.6 18.0 -0.6 -3%
470651011 Tennessee Hamilton 17.0 16.4 -0.6 -4%
470654002 Tennessee Hamilton 16.7 16.3 -0.4 -2%
510030001 Virginia Albemarle 13.8 12.8 -1.0 -7%
510360002 Virginia Charles 13.9 12.9 -1.0 -7%
510410003 Virginia Chesterfield 15.5 14.8 -0.7 -5%
510590030 Virginia Fairfax 18.0 17.3 -0.7 -4%
510690010 Virginia Frederick 18.6 17.9 -0.7 -4%
510870014 Virginia Henrico 16.1 15.3 -0.8 -5%
510870015 Virginia Henrico 14.1 13.1 -1.0 -7%
511071005 Virginia Loudoun 16.5 16.1 -0.4 -2%
511390004 Virginia Page 16.1 15.0 -1.1 -7%
511650003 Virginia Rockingham 17.7 17.2 -0.5 -3%
515200006 Virginia Bristol City 16.2 15.6 -0.6 -4%
516500008 Virginia Hampton City 14.9 14.0 -0.9 -6%
516800015 Virginia Lynchburg City 13.9 13.2 -0.7 -5%
517100024 Virginia Norfolk City 15.7 14.9 -0.8 -5%
517700015 Virginia Roanoke City 16.9 16.2 -0.7 -4%
517750011 Virginia Salem City 15.0 14.4 -0.6 -4%
518100008 Virginia Virginia Beach
City
16.8 16.3 -0.5 -3%
540030003 West Virginia Berkeley 23.5 22.8 -0.7 -3%
540090005 West Virginia Brooke 19.2 18.3 -0.9 -5%
540110006 West Virginia Cabell 18.8 18.0 -0.8 -4%
540291004 West Virginia Hancock 20.5 19.5 -1.0 -5%
540390010 West Virginia Kanawha 17.0 16.1 -0.9 -5%
540391005 West Virginia Kanawha 18.6 17.9 -0.7 -4%
540490006 West Virginia Marion 19.3 18.6 -0.7 -4%
540511002 West Virginia Marshall 23.3 22.6 -0.7 -3%
540610003 West Virginia Monongalia 17.1 16.4 -0.7 -4%
540690010 West Virginia Ohio 17.9 17.0 -0.9 -5%
540810002 West Virginia Raleigh 14.3 13.5 -0.8 -6%
541071002 West Virginia Wood 18.6 17.7 -0.9 -5%
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 37
Daily PM2.5 Design Value – VISTAS12 Domain
CAMx 6.40 2028elv5
Daily PM2.5 Design Value Reduction (2028elv3 – 2028elv5)
Figure 4-18. Comparison of Daily PM2.5 Design Values (µg/m3) for CAMx 6.40 2028elv5
and 2028elv3 Simulations
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 38
Figure 4-19. Scatterplot Comparing Daily (24-hr) Average Predicted PM2.5 Design Values
(µg/m3) at all Monitor Locations for CAMx 6.40 2028elv3 and 2028elv5 Simulations
Performed by VISTAS (Alpine)
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 39
4.4 Scatterplots of Ozone and PM Species Concentrations
Scatterplots of the daily average concentrations of ozone and the various calculated PM
species in local standard time at the Interagency Monitoring for Protected Visual Environment
(IMPROVE) monitors across all modeled days are presented in Figures 4-20 through 4-26. The
CAMx 6.40 20282elv5 results are plotted on the x-axis and the 2028elv3 results are plotted on
the y-axis.
Figure 4-20 exhibits concentrations for ozone with a line of best fit with a slope of
1.0147, an intercept of -0.3588 ppb and an R2 of 0.9986. Results are scattered both above and
below the 1:1 line, with marginally higher concentrations estimated by CAMx 6.40 2028elv3
across the concentration range.
Figure 4-20. Scatterplot Comparing 24-hour Average Predicted Ozone Concentrations
(ppb) for All Days at all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine)
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 40
Scatterplots of the daily average PM2.5 concentrations in local standard time at the
IMPROVE monitors are presented in Figures 4-21 and 4-22 with different axis scaling to
facilitate analysis over the full range of concentrations. The CAMx 6.40 2028elv5 results are
plotted on the x-axis and the 2028elv3 results are plotted on the y-axis. The data has a line of
best fit with a slope of 1.0197, an intercept of 0.0652 µg/m3and an R2 of 0.9978. As expected
with the change in emissions, 2028elv5 predicts lower concentrations across most locations in
the domain although a few sites at lower concentrations (< 20 µg/m3) show significantly higher
concentrations with 2028elv5. These are largely associated with increased NOX (and NO3)
emissions from changes made in the 2028elv5 inventory compared to modeled 2028elv3.
Figure 4-21. Scatterplot Comparing 24-hour Average Predicted PM2.5 Concentrations
(µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine)
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 41
Figure 4-22. Scatterplot Comparing 24-hour Average Predicted PM2.5 Concentrations
(µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine); Modified Scale
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 42
Scatterplots of the daily average sulfate concentrations in local standard time at the
IMPROVE monitors are presented in Figure 4-23. The CAMx 6.40 2028elv5 results are plotted
on the x-axis and the 2028elv3 results are plotted on the y-axis. The data have a line of best fit
with a slope of 1.156, an intercept of -0.0317 µg/m3 and an R2 of 0.9572. As expected with the
change in emissions, 2028elv5 predicts lower concentrations across most locations.
Figure 4-23. Scatterplot Comparing 24-hour Average Predicted Sulfate Concentrations
(µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine)
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 43
Scatterplots of the daily average nitrate concentrations in local standard time at the
IMPROVE monitors are presented in Figure 4-24. The CAMx 6.40 2028elv5 results are plotted
on the x-axis and the 2028elv3 results are plotted on the y-axis. The data have a line of best fit
with a slope of 1.0141, an intercept of -0.0007 µg/m3 and an R2 of 0.9975. As expected with the
change in NOx emissions, 2028elv5 predicts lower concentrations across many locations.
However, many other locations show higher nitrate concentrations. This is likely due to the
decrease in sulfate formation (see Figure 4-23) resulting in more available free ammonia that can
be used to form additional ammonium nitrate.
Figure 4-24. Scatterplot Comparing 24-hour Average Predicted Nitrate Concentrations
(µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40 2028elv5 and
2028elv3 Simulations Performed by VISTAS (Alpine)
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 44
Scatterplots of the daily average organic carbon concentrations in local standard time at
the IMPROVE monitors are presented in Figures 4-24 and 4-25 with different axis scaling to
facilitate analysis over the full range of concentrations. The CAMx 6.40 2028elv5 results are
plotted on the x-axis and the 2028elv3 results are plotted on the y-axis. The data have a line of
best fit with a slope of 1.0012, an intercept of 0.0017 ppb and an R2 of 1.000. The two
simulations show nearly identical results for organic carbon.
Figure 4-25. Scatterplot Comparing 24-hour Average Predicted Organic Carbon
Concentrations (µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40
2028elv5 and 2028elv3 Simulations Performed by VISTAS (Alpine)
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 45
Figure 4-26. Scatterplot Comparing 24-hour Average Predicted Organic Carbon
Concentrations (µg/m3) for All Days all IMPROVE Monitor Locations for CAMx 6.40
2028elv5 and 2028elv3 Simulations Performed by VISTAS (Alpine); Modified Scale
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020 46
5.0 CONCLUSIONS
A comparison has been made between modeled CAMx 6.40 2028elv5 and 2028elv3
simulations as performed on the Alpine Geophysics computer system. The comparison was
conducted for PM2.5 and included an examination both of annual emissions for elevated and low
level sources and annual and daily future year design values at monitors in the modeling domain.
The annual emissions comparisons showed areas of differences across the domain that
are consistent with changes in the modeled 2028 emissions inventories used for this analysis. A
comparison of the annual and daily PM2.5 design values at the monitors in the VISTAS12
modeling domain showed a systematic decrease for all FRM monitors for both values between
the modeled 2028elv3 and 2028elv5 platforms. The greatest change in design values are seen in
the central regions of the VISTAS12 modeling domain with smallest change noted along the
borders of the domain itself.
A comparison of the daily average concentrations at the IMPROVE monitors showed
fairly small differences for ozone between the two simulations with CAMx 6.40 2028elv5
estimating slightly lower values across most of the concentration range. Because of the changes
in emissions between the modeled 2028elv3 and 2028elv5 modeling platforms, PM2.5 and sulfate
generally decreased. Nitrate concentrations showed decreases at some sites and increases at
others. Organic carbon concentrations are nearly identical with the modeled 2028elv3 and
2028elv5 emissions.
The comparison of modeled CAMx 6.40 2028elv3 and 2028elv5 showed differences in
both annual and daily PM2.5 design values as well as in daily concentrations of various PM2.5
species. This is to be expected given the changes made in the modeled 2028 projection emission
inventory across the modeling domain. Alpine Geophysics does not see any features in the
modeling that would preclude the use of the updated emission inventories in CAMx 6.40
2028elv5 platform for use in the VISTAS air quality planning.
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020
Appendix A
Task 6 – Benchmark Run #7 Report Review and 2028 elv3 Reassessment
(see APP_A_ELV3_REASSESSMENT.zip)
CAMx Benchmarking Report #6 (for Run #7)
September 22, 2020
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