Document ID: EPA-HQ-OAR-2019-0587-0019
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2023-08-25T04:00Z

APPENDIX 2A: ADDITIONAL AIR QUALITY MODELING INFORMATION
 Overview
A 2016-based modeling platform was used to project future-year air quality for 2032 to identify areas that would exceed the existing and potential alternative PM NAAQS after accounting for expected emission reductions from `on-the-books' rules. This platform uses the Community Multiscale Air Quality (CMAQ; www.epa.gov/cmaq) model for air quality simulation and incorporates the most recent, complete set of base year emissions information available for national modeling. PM2.5 design values (DVs) were projected to 2032 using relative response factors (RRFs) developed from CMAQ simulations based on emissions estimated for 2016 and projected to 2032.
Air quality ratios, which relate a change in PM2.5 DVs to a change in emissions, were used to estimate the emission reductions needed to just meet the existing and alternative NAAQS in areas projected to exceed the standards in 2032. The emission reduction estimates are used in identifying controls and associated costs of meeting the standards. To inform calculations of the health benefits of meeting standards, annual-mean PM2.5 concentration fields corresponding to cases where the existing and alternative NAAQS are just met were developed. The PM2.5 concentration fields were created by adjusting the 2032 field based on the CMAQ modeling using the incremental change in annual PM2.5 DV needed to meet the standards.  
      The overall steps in the air quality analysis are:
 Project annual and 24-hour PM2.5 DVs to 2032 using a CMAQ simulation for 2016 and a corresponding CMAQ simulation with emissions representative of 2032.
 Develop air quality ratios that relate a change in PM2.5 DVs to a change in emissions for use in estimating the emission reductions needed to just meet the existing and alternative NAAQS. The air quality ratios are developed using the change in DVs associated with CMAQ sensitivity modeling where 50% reductions in anthropogenic emissions were applied in targeted counties relative to previous CMAQ modeling for 2028.
 Using the air quality ratios from Step 2, estimate the emission reductions needed to meet the existing standards (12/35) beyond the 2032 modeling case. For counties in the San Joaquin Valley (SJV) and South Coast Air Basin of California, 75% reductions in anthropogenic NOx emissions are applied in addition to reductions in primary PM2.5 emissions in this step. Concentrations of ammonium nitrate are elevated in SJV and South Coast, and these areas are pursuing both NOx and primary PM2.5 emission reductions to meet the existing standards. For other counties, primary PM2.5 emission reductions alone are applied. The resulting PM2.5 DVs define the 12/35 analytical baseline that is used as the reference case in estimating the incremental costs and benefits of meeting alternative standards relative to existing standards. 
 Using the air quality ratios from Step 2, estimate the primary PM2.5 emission reductions needed to meet the alternative standards beyond the 12/35 analytical baseline.  
 Develop a gridded national PM2.5 concentration field associated with the 2032 case by fusing the 2032 CMAQ modeling with projected monitor concentrations. Adjust the 2032 concentration field according to the changes in PM2.5 DVs needed to meet standard levels to create national PM2.5 concentration fields associated with meeting the existing and alternative standard levels.
 As a sensitivity analysis, estimate the influence on PM2.5 DVs of emission reductions beyond the 2032 modeling that are expected to occur due to EGU retirements and other factors became known or on-the-books after the EGU emissions projections were conducted for the 2032 CMAQ modeling. 
In the remainder of this Appendix, the 2016 air quality model configuration and simulation are described and evaluated in Section 2A.1. The projection of air quality from 2016 to 2032 is described in Section 2A.2. The development of air quality ratios and their application to estimating emission reductions is described in Section 2A.3. The development of the PM2.5 concentration fields is described in Section 2A.4. Finally, the sensitivity analysis for EGU emission reductions beyond the 2032 CMAQ modeling case is described in section 2A.6.
 2A.1	2016 CMAQ Modeling
CMAQ modeling was performed for 2016 to provide a reference simulation for the PM2.5 DV projections to 2032 that are described in section 2A.2.
    2A.1.1	Model Configuration
CMAQ is a three-dimensional grid-based Eulerian air quality model designed to estimate the formation and fate of oxidant precursors, primary and secondary PM2.5 concentrations, and deposition over regional spatial scales (e.g., over the contiguous U.S.) (Appel et al., 2021, Appel et al., 2018, Appel et al., 2017). CMAQ simulates the key processes (e.g., emissions, transport, chemistry, and deposition) that affect primary (directly emitted) and secondary (formed by atmospheric processes) PM using state-of-the-science process parameterizations and input data for emissions, meteorology, and initial and boundary conditions. CMAQ's representation of the chemical and physical mechanisms that govern the formation and fate of air pollution enable simulations the impacts of emission controls on PM2.5 concentrations. 
CMAQ version 5.3.2 (doi: 10.5281/zenodo.4081737) was used to simulate air quality for 2016 to provide a reference simulation for the 2032 air quality projection. The geographic extents of the outer and inner air quality modeling domains are shown in Figure 2A-1. The outer domain covers the 48 contiguous states along with most of Canada and Mexico with a horizontal resolution of 36 x 36 km. Air quality modeling for the 36-km domain was used to provide chemical boundary conditions for the nested 12-km domain simulation, which was used in projecting air quality to the future. Both model domains have 35 vertical layers with a top at about 17.6 km (50 millibars). The chemical boundary and initial conditions for the 36-km modeling domain were developed with version 3.1.1 of the hemispheric CMAQ model (https://www.epa.gov/cmaq/hemispheric-scale-applications). The simulations included 10 days of model spin-up in December 2015 and produced hourly pollutant concentrations for each grid cell across each modeling domain.
Gas-phase chemistry in the CMAQ simulations was based on the Carbon Bond 2006 mechanism (CB6r3) (Emery et al., 2015), and deposition was modeled with the M3DRY parameterization. Aerosol processes were parameterized with the AERO7 module using ISORROPIA II for inorganic aerosol thermodynamics (Fountoukis and Nenes, 2007) and the non-volatile treatment for primary organic aerosol (Appel et al., 2017, Simon and Bhave, 2012). Emissions used were based on version 2 of the 2016 emissions modeling platform as described in detail previously (USEPA, 2022). Emissions of anthropogenic precursors for secondary organic aerosol (SOA) (Murphy et al., 2017) were not added to the simulation beyond what was captured in the National Emissions Inventory. Emissions of biogenic compounds were modeled with the Biogenic Emission Inventory System (BEIS) (Bash et al., 2016). Emissions of sea-spray aerosol (Gantt et al., 2015) were simulated online within CMAQ using 2016 meteorology.  
The 2016 meteorological data were derived from running Version 3.8 of the Weather Research Forecasting Model (WRF) (Skamarock et al., 2008). The meteorological outputs from WRF include hourly-varying horizontal wind components (i.e., speed and direction), temperature, moisture, vertical diffusion rates, and rainfall rates for each grid cell in each vertical layer. Selected physics options used in the WRF simulations include Pleim-Xiu land surface model (Pleim et al., 2001, Xiu and Pleim, 2001), Asymmetric Convective Model version 2 planetary boundary layer scheme (Pleim, 2007), Kain-Fritsch cumulus parameterization (Kain, 2004) utilizing the moisture-advection trigger (Ma and Tan, 2009), Morrison double moment microphysics (Morrison et al., 2005, Morrison and Gettelman, 2008), and RRTMG longwave and shortwave radiation schemes (Iacono et al., 2008). The meteorological model configuration and evaluation have been described previously (USEPA, 2019c).  
      
                                     36US3
12US2
36US3
12US2
Figure 2A-1	Map of the Outer 36US3 (36 x 36 km Horizontal Resolution) and Inner 12US2 (12 x 12 km Horizontal Resolution) Modeling Domains Used for the PM NAAQS RIA
      
    2A.1.2	Model Performance Evaluation
CMAQ predictions were evaluated by comparison with observations from U.S. monitoring networks in 2016. Modeled PM2.5 concentrations were compared with available observations from U.S. EPA's Air Quality System (AQS) database (www.epa.gov/aqs). Modeled concentrations of PM2.5 components (nitrate; sulfate; elemental carbon; EC; and organic carbon, OC) were compared with observations from the Chemical Speciation Network (CSN) and Interagency Monitoring of Protected Visual Environments (IMPROVE) network (USEPA, 2019d). CSN sites tend to be in relatively urban areas and IMPROVE sites in relatively rural areas. Model predictions were paired with observations in space and time by averaging predictions to the observation sampling period and matching predictions with monitors in a model grid cell. Regional performance statistics were summarized according to the U.S. climate regions defined in Figure 2A-2. The absolute and normalized bias and error statistics and Pearson correlation coefficient used in evaluating model performance are defined in Table 2A-1. As described below, performance statistics for this application are generally within the range of model performance statistics reported in previous applications (Kelly et al., 2019, Simon et al., 2012) and suggest that the simulations are suitable for use in our application.
In Figure 2A-3, PM2.5 model performance is shown for the AQS sites having the highest PM2.5 DVs in the county for counties with projected annual PM2.5 DVs greater than 8 g m[-3] or 24-hour DVs greater than 30 g m[-3]. For regions in the eastern U.S., normalized mean biases (NMBs) are within 15% and Pearson correlation coefficients are 0.58 or greater for all regions, except for the South (r=0.37). In western regions, the model is generally biased low compared with observations, with NMBs ranging from -16% in the Northwest to -30% in the Southwest. Underpredictions in western regions could be related to challenges in representing the influence of complex terrain in the 12-km modeling, challenges in simulating wildfire impacts, and underestimates of windblown dust influence. PM2.5 performance statistics by region and season across all sites are provided in Table 2A-2. For the annual period, NMB is within 13% in eastern regions and correlation coefficients are 0.55 or greater in four of the five regions. In the western regions, NMB ranged from 8.0% in the Northwest to -25.9% in the Northern Rockies and Plains and correlation coefficients ranged from 0.10 to 0.43.
Model performance statistics for PM2.5 sulfate by region and season for sites in the CSN and IMPROVE networks are provided in Table 2A-3. The annual NMBs in sulfate predictions are within +-16% for all regions except the Northwest (NMB: 64%) at CSN sites and within +-23% for all regions except the Northwest (NMB: 41%) at IMPROVE sites. Overpredictions of PM2.5 species concentrations in the Northwest have been previously attributed to challenges in simulating the atmospheric mixing height near the Puget Sound and at coastal sites and in simulating wildfire influence on concentrations (Kelly et al., 2019). Concentrations are relatively low in the Northwest compared with the eastern U.S., and mean biases (MBs) in sulfate predictions are <0.25 g m[-3] for both networks in the Northwest. Correlation coefficients over the annual period for sulfate predictions and observations were greater than 0.56 in six of the nine regions for CSN sites and seven of the nine regions at IMPROVE sites. Spatially, sulfate predictions tend to be biased slightly low in the southern and eastern parts of the domain and biased slightly high toward the Northwestern part of the domain (Figure 2A-4 and 2A-5). 
Model performance statistics for PM2.5 nitrate by region and season for sites in the CSN and IMPROVE networks are provided in Table 2A-4. In five of the nine regions, the annual NMB in nitrate predictions is within +-18% at CSN sites and within +-30% at IMPROVE sites. Nitrate predictions are biased low in the West at CSN (NMB: -48.8%) and IMPROVE (NMB: -24.8%) sites. Underpredictions of nitrate during meteorological inversion episodes in western mountain basins have been identified in the past due to challenges in resolving the influence of complex terrain and chemical and meteorological coupling in 12-km modeling (Baker et al., 2011, Kelly et al., 2019). Outside of the Northwest, correlation coefficients for the annual period ranged from 0.59 to 0.79 at CSN sites and 0.52 to 0.75 at IMPROVE sites. Spatially, nitrate predictions tend to be biased high in the eastern US and low in western U.S. (Figure 2A-4 and 2A-5).
Model performance statistics for PM2.5 OC by region and season for sites in the CSN and IMPROVE networks are provided in Table 2A-5. The annual NMB in OC predictions is within +-30% for six of the nine regions at CSN sites and seven of the nine regions at IMPROVE sites. PM2.5 OC predictions are biased high (positive NMB) in eight of the nine regions at CSN sites and five of the nine regions at IMPROVE sites. Correlation coefficients over the annual period for OC predictions and observations were greater than 0.5 in five of the nine regions for CSN sites and four of the nine regions at IMPROVE sites. Spatially, OC predictions tend to be biased high in the eastern U.S. and low in the western U.S., although spatial variability exists (Figure 2A-4 and 2A-5). Modeling of the emissions, volatility and atmospheric chemistry related to organic aerosol formation is an active area of research (USEPA, 2019d).     
Model performance statistics for PM2.5 EC by region and season for sites in the CSN and IMPROVE networks are provided in Table 2A-6. The annual NMB in EC predictions is within +-17% at CSN sites and within +-25% at IMPROVE sites for all regions except the Northwest. As mentioned above, overpredictions of PM2.5 species concentrations in the Northwest may be associated with challenges in modeling the mixing height near the coast, wildfire influence, and other factors. Correlation coefficients for the EC predictions and observations over the annual period were greater than 0.5 in seven of the nine regions for CSN and IMPROVE sites. Spatially, EC predictions tend to be biased slightly low through much of the US with predictions biased high along the coast of the Northeast and Northwest (Figure 2A-4 and 2A-5).
        
                                       
Figure 2A-2	U.S. Climate Regions (Karl and Koss, 1984) Used in the CMAQ Model Performance Evaluation

Table 2A-1	Definition of Statistics Used in the CMAQ Model Performance Evaluation
Statistic
Description
MB (g m[-3]) =  1ni=1nPi-Oi  
Mean bias (MB) is defined as the average difference between predicted (P) and observed (O) concentrations for the total number of samples (n)
RMSE (g m[-3]) = i=1n(Pi-Oi)2/n	
Root mean-squared error (RMSE)
NMB (%) = inPi-OiinOix100	
The normalized mean bias (NMB) is defined as the sum of the difference between predictions and observations divided by the sum of observed values
NME (%) = inPi-OiinOix100	
Normalized mean error (NME) is defined as the sum of the absolute value of the difference between predictions and observations divided by the sum of observed values
r = i=1n(Pi-P)(Oi-O)i=1n(Pi-P)2i=1n(Oi-O)2
Pearson correlation coefficient

                                       
Figure 2A-3	Comparison of CMAQ Predictions of PM2.5 and Observations at AQS Sites for County Highest PM2.5 Monitors with 2032 PM2.5 DVs Greater than 8/30

Table 2A-2	CMAQ Performance Statistics for PM2.5 at AQS Sites in 2016
                                    Region
                                    Season
                                       N
                                     Avg.
                                     Obs.
                                 (g m[-3])
                                     Avg.
                                     Mod.
                                 (g m[-3])
                                      MB
                                 (g m[-3])
                                      NMB
                                      (%)
                                     RMSE
                                 (g m[-3])
                                      NME
                                      (%)
                                       r
                                   Northeast
Winter
                                                                          13305
8.32
10.16
1.84
22.1
5.95
47.6
0.65
                                       
Spring
                                                                          13491
6.86
7.41
0.56
 8.1
3.85
39.0
0.69
                                       
Summer
                                                                          13636
7.20
6.61
-0.58
-8.1
3.45
35.3
0.56
                                       
Fall
                                                                          13413
6.72
7.94
1.22
18.1
4.90
46.8
0.65
                                       
Annual
                                                                          53845
7.27
8.02
0.75
10.3
4.63
42.3
0.64
                                   Southeast
Winter
                                                                          10996
7.37
8.47
1.09
14.8
5.26
41.8
0.48
                                       
Spring
                                                                          11218
8.05
7.60
-0.45
-5.6
3.47
29.9
0.60
                                       
Summer
                                                                          11501
8.01
6.59
-1.43
-17.8
3.55
32.6
0.51
                                       
Fall
                                                                          11454
8.88
8.69
-0.19
-2.2
5.28
32.9
0.63
                                       
Annual
                                                                          45169
8.09
7.83
-0.26
-3.2
4.47
34.0
0.55
                                  Ohio Valley
Winter
                                                                          10729
8.47
10.61
2.15
25.4
5.50
44.8
0.57
                                       
Spring
                                                                          10739
7.76
8.42
0.66
 8.6
4.65
39.3
0.47
                                       
Summer
                                                                          10753
8.54
8.36
-0.18
-2.0
3.93
32.7
0.49
                                       
Fall
                                                                          10761
8.92
10.48
1.56
17.5
5.67
40.2
0.62
                                       
Annual
                                                                          42982
8.42
9.47
1.05
12.5
4.99
39.3
0.55
                                 Upper Midwest
Winter
                                                                           6638
8.19
9.62
1.43
17.4
5.07
42.6
0.65
                                       
Spring
                                                                           6556
7.04
7.53
0.48
 6.9
7.98
44.2
0.30
                                       
Summer
                                                                           6253
6.02
6.00
-0.02
-0.4
3.35
39.9
0.52
                                       
Fall
                                                                           6863
6.42
7.65
1.23
19.2
4.29
45.2
0.65
                                       
Annual
                                                                          26310
6.93
7.73
0.80
11.5
5.46
43.1
0.52
                                     South
Winter
                                                                           7935
6.93
8.35
1.42
20.4
4.77
46.1
0.53
                                       
Spring
                                                                           8266
8.00
7.21
-0.79
-9.9
4.23
35.6
0.51
                                       
Summer
                                                                           7974
9.02
6.20
-2.81
-31.2
5.39
45.6
0.35
                                       
Fall
                                                                           7951
7.96
8.40
0.44
 5.5
4.52
37.0
0.57
                                       
Annual
                                                                          32126
7.98
7.53
-0.44
-5.6
4.74
41.0
0.43
                                       
                                   Southwest
Winter
                                                                           5373
8.12
6.59
-1.53
-18.9
8.45
58.1
0.39
                                       
Spring
                                                                           5447
4.77
5.16
0.39
 8.3
4.07
52.7
0.32
                                       
Summer
                                                                           5548
6.35
3.99
-2.36
-37.2
4.63
49.6
0.28
                                       
Fall
                                                                           5574
5.58
5.08
-0.50
-9.0
4.35
49.5
0.42
                                       
Annual
                                                                          21942
6.20
5.19
-1.00
-16.2
5.64
52.9
0.37
                               N. Rockies & 
                                    Plains
Winter
                                                                           5006
5.80
3.60
-2.21
-38.0
6.77
62.9
0.29
                                       
Spring
                                                                           5238
5.22
4.04
-1.17
-22.5
15.61
61.9
0.11
                                       
Summer
                                                                           5267
6.55
4.32
-2.23
-34.0
34.38
66.1
0.09
                                       
Fall
                                                                           5065
4.58
4.46
-0.12
-2.6
6.55
63.8
0.22
                                       
Annual
                                                                          20576
5.54
4.11
-1.43
-25.9
19.66
63.8
0.10
                                   Northwest
Winter
                                                                           9961
7.90
6.18
-1.72
-21.8
8.67
70.3
0.24
                                       
Spring
                                                                          10059
4.23
5.42
1.19
28.1
4.88
64.3
0.45
                                       
Summer
                                                                           9884
4.72
6.37
1.65
34.9
8.29
69.0
0.44
                                       
Fall
                                                                           9864
5.63
6.32
0.69
12.2
6.67
69.0
0.39
                                       
Annual
                                                                          39768
5.62
6.07
0.45
 8.0
7.28
68.5
0.32
                                     West
Winter
                                                                          10915
9.47
7.53
-1.94
-20.5
6.83
47.0
0.61
                                       
Spring
                                                                          11124
6.79
5.99
-0.79
-11.7
3.80
39.3
0.57
                                       
Summer
                                                                          11516
9.24
7.46
-1.78
-19.3
9.73
43.8
0.25
                                       
Fall
                                                                          11097
8.64
7.15
-1.50
-17.3
6.24
43.8
0.47
                                       
Annual
                                                                          44652
8.54
7.03
-1.50
-17.6
7.01
43.8
0.43

                                       
                                       
Figure 2A-4	NMB in 2016 CMAQ Predictions of PM2.5 Components at CSN and IMPROVE Sites

                                       
Figure 2A-5	NMB in 2016 CMAQ Predictions of PM2.5 Components at CSN and IMPROVE Sites for Monitors in Counties with 2032 PM2.5 DVs Greater than 8/30
Table 2A-3	CMAQ Performance Statistics for PM2.5 Sulfate at CSN and IMPROVE Sites in 2016
                                    Region
                                    Network
                                    Season
                                       N
                                     Avg.
                                     Obs.
                                 (g m[-3])
                                     Avg.
                                     Mod.
                                 (g m[-3])
                                      MB
                                 (g m[-3])
                                      NMB
                                      (%)
                                     RMSE
                                 (g m[-3])
                                      NME
                                      (%)
                                       r
                                   Northeast
                                      CSN
Winter
                                                                            696
                                                                           1.04
                                                                           1.06
                                                                           0.02
                                                                            1.6
                                                                           0.87
                                                                           43.0
                                                                           0.29
                                       
                                       
Spring
                                                                            741
                                                                           0.92
                                                                           1.02
                                                                           0.10
                                                                           10.8
                                                                           0.51
                                                                           38.4
                                                                           0.59
                                       
                                       
Summer
                                                                            736
                                                                           1.16
                                                                           0.98
                                                                          -0.18
                                                                          -15.5
                                                                           0.51
                                                                           28.7
                                                                           0.79
                                       
                                       
Fall
                                                                            705
                                                                           0.88
                                                                           0.96
                                                                           0.09
                                                                            9.8
                                                                           0.55
                                                                           36.7
                                                                           0.70
                                       
                                       
Annual
                                                                           2878
                                                                           1.00
                                                                           1.01
                                                                           0.00
                                                                            0.5
                                                                           0.62
                                                                           36.3
                                                                           0.57
                                       
                                    IMPROVE
Winter
                                                                            349
                                                                           0.72
                                                                           0.67
                                                                          -0.05
                                                                           -7.3
                                                                           0.29
                                                                           30.3
                                                                           0.70
                                       
                                       
Spring
                                                                            387
                                                                           0.73
                                                                           0.72
                                                                          -0.01
                                                                           -1.6
                                                                           0.29
                                                                           26.8
                                                                           0.76
                                       
                                       
Summer
                                                                            396
                                                                           0.70
                                                                           0.62
                                                                          -0.08
                                                                          -11.9
                                                                           0.34
                                                                           32.2
                                                                           0.83
                                       
                                       
Fall
                                                                            375
                                                                           0.58
                                                                           0.57
                                                                          -0.01
                                                                           -1.9
                                                                           0.26
                                                                           30.4
                                                                           0.84
                                       
                                       
Annual
                                                                           1507
                                                                           0.68
                                                                           0.65
                                                                          -0.04
                                                                           -5.8
                                                                           0.30
                                                                           29.9
                                                                           0.80
                                   Southeast
                                      CSN
Winter
                                                                            456
                                                                           0.93
                                                                           1.02
                                                                           0.09
                                                                            9.5
                                                                           0.44
                                                                           35.4
                                                                           0.64
                                       
                                       
Spring
                                                                            490
                                                                           1.11
                                                                           1.08
                                                                          -0.03
                                                                           -2.8
                                                                           0.48
                                                                           30.9
                                                                           0.56
                                       
                                       
Summer
                                                                            463
                                                                           1.11
                                                                           0.89
                                                                          -0.22
                                                                          -19.6
                                                                           0.49
                                                                           32.0
                                                                           0.54
                                       
                                       
Fall
                                                                            447
                                                                           0.95
                                                                           0.97
                                                                           0.02
                                                                            1.9
                                                                           0.36
                                                                           25.7
                                                                           0.72
                                       
                                       
Annual
                                                                           1856
                                                                           1.03
                                                                           0.99
                                                                          -0.04
                                                                           -3.5
                                                                           0.45
                                                                           31.0
                                                                           0.60
                                       
                                    IMPROVE
Winter
                                                                            342
                                                                           0.95
                                                                           0.85
                                                                          -0.10
                                                                          -10.6
                                                                           0.44
                                                                           35.0
                                                                           0.61
                                       
                                       
Spring
                                                                            379
                                                                           1.24
                                                                           0.97
                                                                          -0.27
                                                                          -21.6
                                                                           0.61
                                                                           30.6
                                                                           0.45
                                       
                                       
Summer
                                                                            394
                                                                           1.21
                                                                           0.77
                                                                          -0.44
                                                                          -36.3
                                                                           0.61
                                                                           41.0
                                                                           0.58
                                       
                                       
Fall
                                                                            366
                                                                           1.04
                                                                           0.86
                                                                          -0.17
                                                                          -16.8
                                                                           0.39
                                                                           26.9
                                                                           0.72
                                       
                                       
Annual
                                                                           1481
                                                                           1.12
                                                                           0.86
                                                                          -0.25
                                                                          -22.6
                                                                           0.53
                                                                           33.6
                                                                           0.56
                                  Ohio Valley
                                      CSN
Winter
                                                                            510
                                                                           1.34
                                                                           1.14
                                                                          -0.20
                                                                          -15.0
                                                                           0.81
                                                                           35.3
                                                                           0.52
                                       
                                       
Spring
                                                                            526
                                                                           1.19
                                                                           1.21
                                                                           0.02
                                                                            1.7
                                                                           0.61
                                                                           34.2
                                                                           0.43
                                       
                                       
Summer
                                                                            515
                                                                           1.65
                                                                           1.50
                                                                          -0.15
                                                                           -9.0
                                                                           0.86
                                                                           30.5
                                                                           0.67
                                       
                                       
Fall
                                                                            499
                                                                           1.23
                                                                           1.22
                                                                          -0.01
                                                                           -0.9
                                                                           0.62
                                                                           31.0
                                                                           0.67
                                       
                                       
Annual
                                                                           2050
                                                                           1.35
                                                                           1.27
                                                                          -0.09
                                                                           -6.3
                                                                           0.74
                                                                           32.7
                                                                           0.61
                                       
                                    IMPROVE
Winter
                                                                            192
                                                                           1.07
                                                                           0.89
                                                                          -0.18
                                                                          -16.7
                                                                           0.49
                                                                           30.9
                                                                           0.69
                                       
                                       
Spring
                                                                            213
                                                                           1.16
                                                                           0.95
                                                                          -0.22
                                                                          -18.6
                                                                           0.53
                                                                           28.9
                                                                           0.56
                                       
                                       
Summer
                                                                            211
                                                                           1.48
                                                                           1.12
                                                                          -0.36
                                                                          -24.5
                                                                           0.67
                                                                           33.9
                                                                           0.73
                                       
                                       
Fall
                                                                            202
                                                                           1.27
                                                                           1.04
                                                                          -0.23
                                                                          -17.8
                                                                           0.50
                                                                           28.1
                                                                           0.80
                                       
                                       
Annual
                                                                            818
                                                                           1.25
                                                                           1.00
                                                                          -0.25
                                                                          -19.8
                                                                           0.55
                                                                           30.6
                                                                           0.72
                                 Upper Midwest
                                      CSN
Winter
                                                                            278
                                                                           1.03
                                                                           1.10
                                                                           0.07
                                                                            7.0
                                                                           0.53
                                                                           33.8
                                                                           0.73
                                       
                                       
Spring
                                                                            292
                                                                           0.93
                                                                           1.15
                                                                           0.22
                                                                           24.1
                                                                           0.47
                                                                           39.5
                                                                           0.71
                                       
                                       
Summer
                                                                            275
                                                                           1.04
                                                                           1.08
                                                                           0.04
                                                                            3.5
                                                                           0.47
                                                                           33.4
                                                                           0.82
                                       
                                       
Fall
                                                                            280
                                                                           0.76
                                                                           1.00
                                                                           0.24
                                                                           31.7
                                                                           0.56
                                                                           48.3
                                                                           0.77
                                       
                                       
Annual
                                                                           1125
                                                                           0.94
                                                                           1.08
                                                                           0.14
                                                                           15.4
                                                                           0.51
                                                                           38.1
                                                                           0.75
                                       
                                    IMPROVE
Winter
                                                                            194
                                                                           0.76
                                                                           0.71
                                                                          -0.05
                                                                           -6.9
                                                                           0.30
                                                                           27.6
                                                                           0.83
                                       
                                       
Spring
                                                                            208
                                                                           0.76
                                                                           0.75
                                                                          -0.01
                                                                           -1.4
                                                                           0.32
                                                                           30.3
                                                                           0.71
                                       
                                       
Summer
                                                                            210
                                                                           0.68
                                                                           0.59
                                                                          -0.10
                                                                          -14.3
                                                                           0.32
                                                                           31.0
                                                                           0.88
                                       
                                       
Fall
                                                                            210
                                                                           0.63
                                                                           0.61
                                                                          -0.01
                                                                           -1.8
                                                                           0.34
                                                                           35.3
                                                                           0.79
                                       
                                       
Annual
                                                                            822
                                                                           0.71
                                                                           0.66
                                                                          -0.04
                                                                           -6.1
                                                                           0.32
                                                                           30.9
                                                                           0.81
                                     South
                                      CSN
Winter
                                                                            258
                                                                           0.99
                                                                           1.12
                                                                           0.12
                                                                           12.5
                                                                           0.63
                                                                           39.9
                                                                           0.60
                                       
                                       
Spring
                                                                            273
                                                                           1.16
                                                                           1.08
                                                                          -0.08
                                                                           -7.3
                                                                           0.84
                                                                           38.6
                                                                           0.63
                                       
                                       
Summer
                                                                            264
                                                                           1.49
                                                                           1.07
                                                                          -0.42
                                                                          -28.3
                                                                           0.81
                                                                           39.9
                                                                           0.46
                                       
                                       
Fall
                                                                            257
                                                                           1.31
                                                                           1.24
                                                                          -0.07
                                                                           -5.3
                                                                           0.61
                                                                           32.0
                                                                           0.67
                                       
                                       
Annual
                                                                           1052
                                                                           1.24
                                                                           1.12
                                                                          -0.11
                                                                           -9.2
                                                                           0.73
                                                                           37.5
                                                                           0.56
                                       
                                    IMPROVE
Winter
                                                                            212
                                                                           0.75
                                                                           0.78
                                                                           0.03
                                                                            4.2
                                                                           0.38
                                                                           34.2
                                                                           0.73
                                       
                                       
Spring
                                                                            242
                                                                           0.97
                                                                           0.80
                                                                          -0.17
                                                                          -17.1
                                                                           0.65
                                                                           38.5
                                                                           0.60
                                       
                                       
Summer
                                                                            221
                                                                           1.42
                                                                           0.77
                                                                          -0.65
                                                                          -45.5
                                                                           0.91
                                                                           48.4
                                                                           0.55
                                       
                                       
Fall
                                                                            234
                                                                           1.10
                                                                           0.89
                                                                          -0.21
                                                                          -19.1
                                                                           0.51
                                                                           33.1
                                                                           0.73
                                       
                                       
Annual
                                                                            909
                                                                           1.06
                                                                           0.81
                                                                          -0.25
                                                                          -23.4
                                                                           0.64
                                                                           39.6
                                                                           0.59
                                   Southwest
                                      CSN
Winter
                                                                            189
                                                                           0.50
                                                                           0.51
                                                                           0.01
                                                                            1.9
                                                                           0.72
                                                                           74.3
                                                                           0.19
                                       
                                       
Spring
                                                                            195
                                                                           0.40
                                                                           0.67
                                                                           0.27
                                                                           68.7
                                                                           0.36
                                                                           77.6
                                                                           0.38
                                       
                                       
Summer
                                                                            192
                                                                           0.70
                                                                           0.49
                                                                          -0.22
                                                                          -30.7
                                                                           0.45
                                                                           45.2
                                                                           0.13
                                       
                                       
Fall
                                                                            200
                                                                           0.50
                                                                           0.52
                                                                           0.02
                                                                            3.0
                                                                           0.28
                                                                           45.1
                                                                           0.35
                                       
                                       
Annual
                                                                            776
                                                                           0.53
                                                                           0.55
                                                                           0.02
                                                                            4.1
                                                                           0.48
                                                                           58.1
                                                                           0.13
                                       
                                    IMPROVE
Winter
                                                                            829
                                                                           0.25
                                                                           0.39
                                                                           0.14
                                                                           57.0
                                                                           0.37
                                                                           83.1
                                                                           0.36
                                       
                                       
Spring
                                                                            909
                                                                           0.39
                                                                           0.62
                                                                           0.23
                                                                           60.3
                                                                           0.35
                                                                           70.8
                                                                           0.47
                                       
                                       
Summer
                                                                            900
                                                                           0.65
                                                                           0.40
                                                                          -0.25
                                                                          -38.3
                                                                           0.48
                                                                           49.3
                                                                           0.32
                                       
                                       
Fall
                                                                            877
                                                                           0.47
                                                                           0.40
                                                                          -0.07
                                                                          -14.7
                                                                           0.30
                                                                           45.4
                                                                           0.38
                                       
                                       
Annual
                                                                           3515
                                                                           0.44
                                                                           0.45
                                                                           0.01
                                                                            3.1
                                                                           0.38
                                                                           57.7
                                                                           0.28
                               N. Rockies & 
                                    Plains
                                      CSN
Winter
                                                                            141
                                                                           0.51
                                                                           0.62
                                                                           0.11
                                                                           21.0
                                                                           0.46
                                                                           54.4
                                                                           0.70
                                       
                                       
Spring
                                                                            145
                                                                           0.54
                                                                           0.65
                                                                           0.11
                                                                           20.5
                                                                           0.32
                                                                           45.7
                                                                           0.68
                                       
                                       
Summer
                                                                            135
                                                                           0.54
                                                                           0.55
                                                                           0.01
                                                                            1.5
                                                                           0.29
                                                                           37.5
                                                                           0.79
                                       
                                       
Fall
                                                                            139
                                                                           0.47
                                                                           0.55
                                                                           0.08
                                                                           17.5
                                                                           0.30
                                                                           43.8
                                                                           0.80
                                       
                                       
Annual
                                                                            560
                                                                           0.51
                                                                           0.59
                                                                           0.08
                                                                           15.2
                                                                           0.35
                                                                           45.4
                                                                           0.73
                                       
                                    IMPROVE
Winter
                                                                            542
                                                                           0.32
                                                                           0.42
                                                                           0.10
                                                                           31.3
                                                                           0.29
                                                                           66.1
                                                                           0.73
                                       
                                       
Spring
                                                                            573
                                                                           0.38
                                                                           0.50
                                                                           0.13
                                                                           34.0
                                                                           0.25
                                                                           53.3
                                                                           0.67
                                       
                                       
Summer
                                                                            603
                                                                           0.36
                                                                           0.40
                                                                           0.04
                                                                           10.0
                                                                           0.21
                                                                           42.2
                                                                           0.54
                                       
                                       
Fall
                                                                            574
                                                                           0.34
                                                                           0.40
                                                                           0.06
                                                                           17.7
                                                                           0.26
                                                                           48.8
                                                                           0.70
                                       
                                       
Annual
                                                                           2292
                                                                           0.35
                                                                           0.43
                                                                           0.08
                                                                           22.9
                                                                           0.25
                                                                           52.0
                                                                           0.67
                                   Northwest
                                      CSN
Winter
                                                                            129
                                                                           0.30
                                                                           0.57
                                                                           0.27
                                                                           92.1
                                                                           0.51
                                                                          119.4
                                                                           0.21
                                       
                                       
Spring
                                                                            135
                                                                           0.38
                                                                           0.73
                                                                           0.36
                                                                           93.6
                                                                           0.47
                                                                           97.7
                                                                           0.64
                                       
                                       
Summer
                                                                            135
                                                                           0.50
                                                                           0.60
                                                                           0.10
                                                                           20.8
                                                                           0.34
                                                                           53.8
                                                                           0.44
                                       
                                       
Fall
                                                                            134
                                                                           0.34
                                                                           0.59
                                                                           0.24
                                                                           70.7
                                                                           0.42
                                                                           93.6
                                                                           0.39
                                       
                                       
Annual
                                                                            533
                                                                           0.38
                                                                           0.62
                                                                           0.24
                                                                           64.0
                                                                           0.44
                                                                           86.3
                                                                           0.38
                                       
                                    IMPROVE
Winter
                                                                            405
                                                                           0.15
                                                                           0.26
                                                                           0.11
                                                                           75.6
                                                                           0.20
                                                                           97.5
                                                                           0.65
                                       
                                       
Spring
                                                                            474
                                                                           0.30
                                                                           0.49
                                                                           0.19
                                                                           61.2
                                                                           0.29
                                                                           69.4
                                                                           0.73
                                       
                                       
Summer
                                                                            488
                                                                           0.35
                                                                           0.39
                                                                           0.04
                                                                           11.8
                                                                           0.23
                                                                           48.9
                                                                           0.45
                                       
                                       
Fall
                                                                            471
                                                                           0.24
                                                                           0.33
                                                                           0.09
                                                                           38.0
                                                                           0.24
                                                                           71.2
                                                                           0.62
                                       
                                       
Annual
                                                                           1838
                                                                           0.27
                                                                           0.37
                                                                           0.11
                                                                           40.5
                                                                           0.24
                                                                           66.2
                                                                           0.62
                                     West
                                      CSN
Winter
                                                                            246
                                                                           0.46
                                                                           0.61
                                                                           0.15
                                                                           33.1
                                                                           0.44
                                                                           70.5
                                                                           0.35
                                       
                                       
Spring
                                                                            257
                                                                           0.76
                                                                           0.80
                                                                           0.04
                                                                            5.1
                                                                           0.53
                                                                           49.5
                                                                           0.44
                                       
                                       
Summer
                                                                            258
                                                                           1.31
                                                                           0.74
                                                                          -0.58
                                                                          -43.9
                                                                           1.25
                                                                           51.1
                                                                           0.35
                                       
                                       
Fall
                                                                            235
                                                                           0.77
                                                                           0.65
                                                                          -0.12
                                                                          -16.1
                                                                           0.52
                                                                           47.2
                                                                           0.49
                                       
                                       
Annual
                                                                            996
                                                                           0.83
                                                                           0.70
                                                                          -0.13
                                                                          -15.8
                                                                           0.77
                                                                           52.5
                                                                           0.37
                                       
                                    IMPROVE
Winter
                                                                            510
                                                                           0.22
                                                                           0.38
                                                                           0.16
                                                                           74.2
                                                                           0.33
                                                                          104.3
                                                                           0.36

Spring
                                                                            549
                                                                           0.51
                                                                           0.61
                                                                           0.10
                                                                           20.5
                                                                           0.36
                                                                           53.8
                                                                           0.39

Summer
                                                                            548
                                                                           0.74
                                                                           0.52
                                                                          -0.22
                                                                          -30.2
                                                                           0.49
                                                                           47.6
                                                                           0.36

Fall
                                                                            527
                                                                           0.47
                                                                           0.44
                                                                          -0.03
                                                                           -6.0
                                                                           0.30
                                                                           47.1
                                                                           0.45

Annual
                                                                           2134
                                                                           0.49
                                                                           0.49
                                                                           0.00
                                                                            0.3
                                                                           0.38
                                                                           55.2
                                                                           0.39

Table 2A-4	CMAQ Performance Statistics for PM2.5 Nitrate at CSN and IMPROVE Sites in 2016
                                    Region
                                    Network
                                    Season
                                       N
                                     Avg.
                                     Obs.
                                 (g m[-3])
                                     Avg.
                                     Mod.
                                 (g m[-3])
                                      MB
                                 (g m[-3])
                                      NMB
                                      (%)
                                     RMSE
                                 (g m[-3])
                                      NME
                                      (%)
                                       r
                                   Northeast
                                      CSN
Winter
                                                                            696
                                                                           1.72
                                                                           2.44
                                                                           0.72
                                                                           42.1
                                                                           1.55
                                                                           61.7
                                                                           0.74
                                       
                                       
Spring
                                                                            741
                                                                           0.86
                                                                           0.84
                                                                          -0.01
                                                                           -1.7
                                                                           0.72
                                                                           55.6
                                                                           0.77
                                       
                                       
Summer
                                                                            736
                                                                           0.32
                                                                           0.21
                                                                          -0.12
                                                                          -36.2
                                                                           0.30
                                                                           62.2
                                                                           0.52
                                       
                                       
Fall
                                                                            705
                                                                           0.64
                                                                           0.72
                                                                           0.08
                                                                           12.0
                                                                           0.65
                                                                           61.0
                                                                           0.66
                                       
                                       
Annual
                                                                           2878
                                                                           0.88
                                                                           1.04
                                                                           0.16
                                                                           18.3
                                                                           0.92
                                                                           60.1
                                                                           0.79
                                       
                                    IMPROVE
Winter
                                                                            349
                                                                           0.49
                                                                           1.05
                                                                           0.56
                                                                          113.3
                                                                           0.99
                                                                          127.3
                                                                           0.66
                                       
                                       
Spring
                                                                            387
                                                                           0.32
                                                                           0.32
                                                                           0.00
                                                                            1.3
                                                                           0.40
                                                                           65.7
                                                                           0.61
                                       
                                       
Summer
                                                                            396
                                                                           0.15
                                                                           0.20
                                                                           0.05
                                                                           31.1
                                                                           0.26
                                                                           91.3
                                                                           0.40
                                       
                                       
Fall
                                                                            375
                                                                           0.22
                                                                           0.30
                                                                           0.07
                                                                           32.1
                                                                           0.35
                                                                           82.5
                                                                           0.57
                                       
                                       
Annual
                                                                           1507
                                                                           0.29
                                                                           0.45
                                                                           0.16
                                                                           55.2
                                                                           0.56
                                                                           96.6
                                                                           0.62
                                   Southeast
                                      CSN
Winter
                                                                            456
                                                                           0.68
                                                                           1.33
                                                                           0.66
                                                                           97.0
                                                                           1.15
                                                                          112.4
                                                                           0.64
                                       
                                       
Spring
                                                                            490
                                                                           0.37
                                                                           0.37
                                                                          -0.01
                                                                           -1.5
                                                                           0.41
                                                                           63.1
                                                                           0.60
                                       
                                       
Summer
                                                                            463
                                                                           0.20
                                                                           0.22
                                                                           0.02
                                                                            9.2
                                                                           0.21
                                                                           70.8
                                                                           0.35
                                       
                                       
Fall
                                                                            450
                                                                           0.33
                                                                           0.43
                                                                           0.11
                                                                           32.8
                                                                           0.46
                                                                           76.6
                                                                           0.62
                                       
                                       
Annual
                                                                           1859
                                                                           0.39
                                                                           0.58
                                                                           0.19
                                                                           48.4
                                                                           0.66
                                                                           87.6
                                                                           0.68
                                       
                                    IMPROVE
Winter
                                                                            342
                                                                           0.49
                                                                           0.63
                                                                           0.14
                                                                           27.5
                                                                           0.50
                                                                           70.9
                                                                           0.60
                                       
                                       
Spring
                                                                            379
                                                                           0.34
                                                                           0.26
                                                                          -0.08
                                                                          -24.1
                                                                           0.29
                                                                           56.2
                                                                           0.42
                                       
                                       
Summer
                                                                            394
                                                                           0.19
                                                                           0.19
                                                                           0.01
                                                                            4.1
                                                                           0.16
                                                                           59.5
                                                                           0.44
                                       
                                       
Fall
                                                                            366
                                                                           0.29
                                                                           0.28
                                                                          -0.01
                                                                           -3.7
                                                                           0.29
                                                                           61.9
                                                                           0.61
                                       
                                       
Annual
                                                                           1481
                                                                           0.32
                                                                           0.33
                                                                           0.01
                                                                            3.0
                                                                           0.33
                                                                           63.2
                                                                           0.61
                                  Ohio Valley
                                      CSN
Winter
                                                                            510
                                                                           2.41
                                                                           2.37
                                                                          -0.04
                                                                           -1.8
                                                                           1.63
                                                                           43.5
                                                                           0.59
                                       
                                       
Spring
                                                                            526
                                                                           0.91
                                                                           0.87
                                                                          -0.03
                                                                           -3.5
                                                                           1.04
                                                                           64.7
                                                                           0.44
                                       
                                       
Summer
                                                                            515
                                                                           0.37
                                                                           0.37
                                                                           0.00
                                                                            1.0
                                                                           0.48
                                                                           78.3
                                                                           0.27
                                       
                                       
Fall
                                                                            499
                                                                           0.82
                                                                           0.84
                                                                           0.02
                                                                            2.7
                                                                           0.81
                                                                           58.4
                                                                           0.59
                                       
                                       
Annual
                                                                           2050
                                                                           1.13
                                                                           1.11
                                                                          -0.01
                                                                           -1.1
                                                                           1.08
                                                                           53.4
                                                                           0.69
                                       
                                    IMPROVE
Winter
                                                                            192
                                                                           1.31
                                                                           1.07
                                                                          -0.24
                                                                          -18.5
                                                                           1.15
                                                                           55.2
                                                                           0.54
                                       
                                       
Spring
                                                                            213
                                                                           0.53
                                                                           0.32
                                                                          -0.21
                                                                          -39.2
                                                                           0.65
                                                                           59.4
                                                                           0.60
                                       
                                       
Summer
                                                                            211
                                                                           0.19
                                                                           0.18
                                                                          -0.01
                                                                           -5.5
                                                                           0.21
                                                                           68.0
                                                                           0.32
                                       
                                       
Fall
                                                                            202
                                                                           0.50
                                                                           0.37
                                                                          -0.13
                                                                          -26.1
                                                                           0.60
                                                                           62.4
                                                                           0.55
                                       
                                       
Annual
                                                                            818
                                                                           0.62
                                                                           0.47
                                                                          -0.15
                                                                          -23.5
                                                                           0.72
                                                                           58.6
                                                                           0.64
                                 Upper Midwest
                                      CSN
Winter
                                                                            278
                                                                           2.76
                                                                           2.72
                                                                          -0.04
                                                                           -1.5
                                                                           1.54
                                                                           37.6
                                                                           0.75
                                       
                                       
Spring
                                                                            292
                                                                           1.15
                                                                           1.14
                                                                          -0.01
                                                                           -1.1
                                                                           1.27
                                                                           58.0
                                                                           0.52
                                       
                                       
Summer
                                                                            275
                                                                           0.35
                                                                           0.36
                                                                           0.01
                                                                            3.8
                                                                           0.55
                                                                           85.8
                                                                           0.27
                                       
                                       
Fall
                                                                            280
                                                                           0.81
                                                                           0.82
                                                                           0.01
                                                                            1.1
                                                                           0.87
                                                                           55.9
                                                                           0.65
                                       
                                       
Annual
                                                                           1125
                                                                           1.27
                                                                           1.26
                                                                          -0.01
                                                                           -0.6
                                                                           1.12
                                                                           48.6
                                                                           0.77
                                       
                                    IMPROVE
Winter
                                                                            194
                                                                           1.44
                                                                           1.11
                                                                          -0.34
                                                                          -23.3
                                                                           1.32
                                                                           49.9
                                                                           0.66
                                       
                                       
Spring
                                                                            208
                                                                           0.58
                                                                           0.35
                                                                          -0.22
                                                                          -38.3
                                                                           0.78
                                                                           58.6
                                                                           0.67
                                       
                                       
Summer
                                                                            210
                                                                           0.12
                                                                           0.14
                                                                           0.02
                                                                           20.5
                                                                           0.16
                                                                           75.5
                                                                           0.55
                                       
                                       
Fall
                                                                            210
                                                                           0.33
                                                                           0.27
                                                                          -0.06
                                                                          -18.1
                                                                           0.50
                                                                           65.4
                                                                           0.52
                                       
                                       
Annual
                                                                            822
                                                                           0.60
                                                                           0.46
                                                                          -0.14
                                                                          -24.0
                                                                           0.80
                                                                           55.5
                                                                           0.72
                                     South
                                      CSN
Winter
                                                                            258
                                                                           0.97
                                                                           1.02
                                                                           0.06
                                                                            5.8
                                                                           0.85
                                                                           53.7
                                                                           0.63
                                       
                                       
Spring
                                                                            273
                                                                           0.35
                                                                           0.30
                                                                          -0.06
                                                                          -16.1
                                                                           0.36
                                                                           61.9
                                                                           0.52
                                       
                                       
Summer
                                                                            264
                                                                           0.25
                                                                           0.25
                                                                           0.00
                                                                            0.4
                                                                           0.26
                                                                           68.5
                                                                           0.31
                                       
                                       
Fall
                                                                            257
                                                                           0.35
                                                                           0.37
                                                                           0.02
                                                                            6.3
                                                                           0.38
                                                                           69.0
                                                                           0.46
                                       
                                       
Annual
                                                                           1052
                                                                           0.48
                                                                           0.48
                                                                           0.00
                                                                            1.0
                                                                           0.51
                                                                           60.0
                                                                           0.68
                                       
                                    IMPROVE
Winter
                                                                            212
                                                                           0.81
                                                                           0.65
                                                                          -0.16
                                                                          -19.3
                                                                           0.73
                                                                           54.1
                                                                           0.63
                                       
                                       
Spring
                                                                            242
                                                                           0.34
                                                                           0.24
                                                                          -0.10
                                                                          -30.4
                                                                           0.37
                                                                           57.1
                                                                           0.59
                                       
                                       
Summer
                                                                            221
                                                                           0.21
                                                                           0.14
                                                                          -0.07
                                                                          -35.1
                                                                           0.17
                                                                           57.5
                                                                           0.42
                                       
                                       
Fall
                                                                            234
                                                                           0.24
                                                                           0.18
                                                                          -0.06
                                                                          -24.7
                                                                           0.26
                                                                           50.3
                                                                           0.53
                                       
                                       
Annual
                                                                            909
                                                                           0.39
                                                                           0.30
                                                                          -0.10
                                                                          -24.8
                                                                           0.43
                                                                           54.6
                                                                           0.68
                                   Southwest
                                      CSN
Winter
                                                                            189
                                                                           2.86
                                                                           1.00
                                                                          -1.86
                                                                          -65.2
                                                                           4.52
                                                                           73.3
                                                                           0.51
                                       
                                       
Spring
                                                                            195
                                                                           0.48
                                                                           0.30
                                                                          -0.18
                                                                          -37.9
                                                                           0.54
                                                                           55.2
                                                                           0.66
                                       
                                       
Summer
                                                                            192
                                                                           0.26
                                                                           0.13
                                                                          -0.13
                                                                          -50.0
                                                                           0.32
                                                                           84.4
                                                                          -0.09
                                       
                                       
Fall
                                                                            200
                                                                           0.59
                                                                           0.36
                                                                          -0.23
                                                                          -38.6
                                                                           0.91
                                                                           76.4
                                                                           0.57
                                       
                                       
Annual
                                                                            776
                                                                           1.03
                                                                           0.44
                                                                          -0.59
                                                                          -57.1
                                                                           2.30
                                                                           72.3
                                                                           0.59
                                       
                                    IMPROVE
Winter
                                                                            829
                                                                           0.28
                                                                           0.16
                                                                          -0.12
                                                                          -42.7
                                                                           0.51
                                                                           71.6
                                                                           0.55
                                       
                                       
Spring
                                                                            909
                                                                           0.17
                                                                           0.14
                                                                          -0.03
                                                                          -19.5
                                                                           0.15
                                                                           56.3
                                                                           0.27
                                       
                                       
Summer
                                                                            900
                                                                           0.15
                                                                           0.07
                                                                          -0.09
                                                                          -56.0
                                                                           0.14
                                                                           60.1
                                                                           0.55
                                       
                                       
Fall
                                                                            877
                                                                           0.12
                                                                           0.09
                                                                          -0.04
                                                                          -29.2
                                                                           0.13
                                                                           59.3
                                                                           0.44
                                       
                                       
Annual
                                                                           3515
                                                                           0.18
                                                                           0.11
                                                                          -0.07
                                                                          -37.5
                                                                           0.28
                                                                           63.2
                                                                           0.52
                               N. Rockies & 
                                    Plains
                                      CSN
Winter
                                                                            141
                                                                           1.19
                                                                           1.02
                                                                          -0.17
                                                                          -14.3
                                                                           1.23
                                                                           54.6
                                                                           0.61
                                       
                                       
Spring
                                                                            145
                                                                           0.50
                                                                           0.36
                                                                          -0.14
                                                                          -28.3
                                                                           0.53
                                                                           53.5
                                                                           0.78
                                       
                                       
Summer
                                                                            135
                                                                           0.17
                                                                           0.12
                                                                          -0.05
                                                                          -27.3
                                                                           0.20
                                                                           64.6
                                                                           0.48
                                       
                                       
Fall
                                                                            139
                                                                           0.31
                                                                           0.34
                                                                           0.02
                                                                            7.1
                                                                           0.45
                                                                           70.3
                                                                           0.58
                                       
                                       
Annual
                                                                            560
                                                                           0.55
                                                                           0.46
                                                                          -0.08
                                                                          -15.5
                                                                           0.72
                                                                           57.3
                                                                           0.68
                                       
                                    IMPROVE
Winter
                                                                            542
                                                                           0.39
                                                                           0.24
                                                                          -0.15
                                                                          -37.8
                                                                           0.57
                                                                           68.6
                                                                           0.64
                                       
                                       
Spring
                                                                            573
                                                                           0.16
                                                                           0.13
                                                                          -0.04
                                                                          -23.4
                                                                           0.22
                                                                           67.4
                                                                           0.33
                                       
                                       
Summer
                                                                            603
                                                                           0.08
                                                                           0.05
                                                                          -0.03
                                                                          -42.2
                                                                           0.08
                                                                           58.2
                                                                           0.34
                                       
                                       
Fall
                                                                            574
                                                                           0.11
                                                                           0.11
                                                                           0.00
                                                                            2.0
                                                                           0.17
                                                                           76.6
                                                                           0.45
                                       
                                       
Annual
                                                                           2292
                                                                           0.18
                                                                           0.13
                                                                          -0.05
                                                                          -29.1
                                                                           0.31
                                                                           68.3
                                                                           0.63
                                   Northwest
                                      CSN
Winter
                                                                            129
                                                                           1.33
                                                                           0.98
                                                                          -0.35
                                                                          -26.4
                                                                           2.25
                                                                           82.2
                                                                           0.33
                                       
                                       
Spring
                                                                            135
                                                                           0.38
                                                                           1.09
                                                                           0.70
                                                                          183.8
                                                                           2.08
                                                                          211.6
                                                                           0.56
                                       
                                       
Summer
                                                                            135
                                                                           0.25
                                                                           1.26
                                                                           1.01
                                                                          396.6
                                                                           1.83
                                                                          406.9
                                                                           0.42
                                       
                                       
Fall
                                                                            134
                                                                           0.51
                                                                           0.95
                                                                           0.44
                                                                           86.7
                                                                           1.21
                                                                          142.4
                                                                           0.19
                                       
                                       
Annual
                                                                            533
                                                                           0.61
                                                                           1.07
                                                                           0.46
                                                                           75.0
                                                                           1.88
                                                                          149.4
                                                                           0.17
                                       
                                    IMPROVE
Winter
                                                                            405
                                                                           0.33
                                                                           0.23
                                                                          -0.10
                                                                          -30.6
                                                                           0.78
                                                                           91.5
                                                                           0.32
                                       
                                       
Spring
                                                                            474
                                                                           0.15
                                                                           0.26
                                                                           0.11
                                                                           75.0
                                                                           0.77
                                                                          113.7
                                                                           0.56
                                       
                                       
Summer
                                                                            488
                                                                           0.14
                                                                           0.30
                                                                           0.16
                                                                          111.7
                                                                           0.80
                                                                          168.2
                                                                           0.39
                                       
                                       
Fall
                                                                            471
                                                                           0.17
                                                                           0.23
                                                                           0.07
                                                                           39.5
                                                                           0.52
                                                                          108.8
                                                                           0.39
                                       
                                       
Annual
                                                                           1838
                                                                           0.19
                                                                           0.26
                                                                           0.07
                                                                           34.1
                                                                           0.73
                                                                          114.8
                                                                           0.27
                                     West
                                      CSN
Winter
                                                                            246
                                                                           3.02
                                                                           1.41
                                                                          -1.61
                                                                          -53.4
                                                                           3.59
                                                                           61.7
                                                                           0.66
                                       
                                       
Spring
                                                                            257
                                                                           1.25
                                                                           0.70
                                                                          -0.55
                                                                          -43.9
                                                                           1.51
                                                                           53.2
                                                                           0.76
                                       
                                       
Summer
                                                                            258
                                                                           1.16
                                                                           0.74
                                                                          -0.42
                                                                          -36.3
                                                                           1.18
                                                                           51.3
                                                                           0.64
                                       
                                       
Fall
                                                                            235
                                                                           1.73
                                                                           0.81
                                                                          -0.92
                                                                          -53.4
                                                                           2.57
                                                                           69.2
                                                                           0.54
                                       
                                       
Annual
                                                                            996
                                                                           1.78
                                                                           0.91
                                                                          -0.87
                                                                          -48.8
                                                                           2.39
                                                                           60.2
                                                                           0.67
                                       
                                    IMPROVE
Winter
                                                                            510
                                                                           0.50
                                                                           0.36
                                                                          -0.14
                                                                          -28.2
                                                                           0.94
                                                                           60.4
                                                                           0.80

Spring
                                                                            549
                                                                           0.41
                                                                           0.34
                                                                          -0.07
                                                                          -17.3
                                                                           0.36
                                                                           47.9
                                                                           0.81

Summer
                                                                            548
                                                                           0.34
                                                                           0.28
                                                                          -0.06
                                                                          -17.5
                                                                           0.38
                                                                           55.1
                                                                           0.45

Fall
                                                                            527
                                                                           0.44
                                                                           0.28
                                                                          -0.15
                                                                          -34.6
                                                                           0.86
                                                                           61.8
                                                                           0.75

Annual
                                                                           2134
                                                                           0.42
                                                                           0.32
                                                                          -0.10
                                                                          -24.8
                                                                           0.68
                                                                           56.5
                                                                           0.75

Table 2A-5	CMAQ Performance Statistics for PM2.5 EC at CSN and IMPROVE Sites in 2016
                                    Region
                                    Network
                                    Season
                                       N
                                     Avg.
                                     Obs.
                                 (g m[-3])
                                     Avg.
                                     Mod.
                                 (g m[-3])
                                      MB
                                 (g m[-3])
                                      NMB
                                      (%)
                                     RMSE
                                 (g m[-3])
                                      NME
                                      (%)
                                       r
                                   Northeast
                                      CSN
Winter
                                                                            672
                                                                           0.67
                                                                           0.78
                                                                           0.11
                                                                           16.5
                                                                           0.68
                                                                           53.7
                                                                           0.60
                                       
                                       
Spring
                                                                            736
                                                                           0.58
                                                                           0.55
                                                                          -0.03
                                                                           -4.8
                                                                           0.44
                                                                           43.2
                                                                           0.58
                                       
                                       
Summer
                                                                            725
                                                                           0.58
                                                                           0.50
                                                                          -0.08
                                                                          -13.5
                                                                           0.35
                                                                           39.6
                                                                           0.58
                                       
                                       
Fall
                                                                            725
                                                                           0.62
                                                                           0.70
                                                                           0.07
                                                                           11.9
                                                                           0.56
                                                                           47.9
                                                                           0.58
                                       
                                       
Annual
                                                                           2858
                                                                           0.61
                                                                           0.63
                                                                           0.02
                                                                            2.9
                                                                           0.52
                                                                           46.3
                                                                           0.58
                                       
                                    IMPROVE
Winter
                                                                            373
                                                                           0.19
                                                                           0.28
                                                                           0.09
                                                                           46.4
                                                                           0.17
                                                                           62.3
                                                                           0.83
                                       
                                       
Spring
                                                                            422
                                                                           0.15
                                                                           0.18
                                                                           0.03
                                                                           16.9
                                                                           0.10
                                                                           43.4
                                                                           0.85
                                       
                                       
Summer
                                                                            423
                                                                           0.16
                                                                           0.17
                                                                           0.01
                                                                            4.6
                                                                           0.09
                                                                           39.1
                                                                           0.82
                                       
                                       
Fall
                                                                            406
                                                                           0.19
                                                                           0.21
                                                                           0.02
                                                                           11.3
                                                                           0.15
                                                                           41.6
                                                                           0.82
                                       
                                       
Annual
                                                                           1624
                                                                           0.17
                                                                           0.21
                                                                           0.03
                                                                           19.7
                                                                           0.13
                                                                           46.6
                                                                           0.82
                                   Southeast
                                      CSN
Winter
                                                                            392
                                                                           0.59
                                                                           0.58
                                                                          -0.01
                                                                           -1.3
                                                                           0.36
                                                                           41.6
                                                                           0.60
                                       
                                       
Spring
                                                                            424
                                                                           0.55
                                                                           0.43
                                                                          -0.13
                                                                          -23.3
                                                                           0.34
                                                                           40.3
                                                                           0.63
                                       
                                       
Summer
                                                                            388
                                                                           0.43
                                                                           0.41
                                                                          -0.02
                                                                           -5.0
                                                                           0.30
                                                                           47.9
                                                                           0.41
                                       
                                       
Fall
                                                                            374
                                                                           0.63
                                                                           0.55
                                                                          -0.08
                                                                          -12.6
                                                                           0.41
                                                                           41.4
                                                                           0.63
                                       
                                       
Annual
                                                                           1578
                                                                           0.55
                                                                           0.49
                                                                          -0.06
                                                                          -11.1
                                                                           0.35
                                                                           42.4
                                                                           0.59
                                       
                                    IMPROVE
Winter
                                                                            376
                                                                           0.28
                                                                           0.26
                                                                          -0.02
                                                                           -5.9
                                                                           0.34
                                                                           48.5
                                                                           0.52
                                       
                                       
Spring
                                                                            416
                                                                           0.32
                                                                           0.21
                                                                          -0.11
                                                                          -34.4
                                                                           0.66
                                                                           50.0
                                                                           0.29
                                       
                                       
Summer
                                                                            425
                                                                           0.23
                                                                           0.17
                                                                          -0.06
                                                                          -24.2
                                                                           0.25
                                                                           45.4
                                                                           0.60
                                       
                                       
Fall
                                                                            395
                                                                           0.36
                                                                           0.26
                                                                          -0.10
                                                                          -28.0
                                                                           0.26
                                                                           38.3
                                                                           0.85
                                       
                                       
Annual
                                                                           1612
                                                                           0.30
                                                                           0.23
                                                                          -0.07
                                                                          -24.2
                                                                           0.42
                                                                           45.2
                                                                           0.51
                                  Ohio Valley
                                      CSN
Winter
                                                                            498
                                                                           0.49
                                                                           0.57
                                                                           0.07
                                                                           15.1
                                                                           0.33
                                                                           45.0
                                                                           0.64
                                       
                                       
Spring
                                                                            548
                                                                           0.54
                                                                           0.45
                                                                          -0.09
                                                                          -16.3
                                                                           0.31
                                                                           38.4
                                                                           0.59
                                       
                                       
Summer
                                                                            523
                                                                           0.61
                                                                           0.47
                                                                          -0.15
                                                                          -24.0
                                                                           0.35
                                                                           39.6
                                                                           0.44
                                       
                                       
Fall
                                                                            523
                                                                           0.71
                                                                           0.62
                                                                          -0.09
                                                                          -12.7
                                                                           0.41
                                                                           36.1
                                                                           0.63
                                       
                                       
Annual
                                                                           2092
                                                                           0.59
                                                                           0.52
                                                                          -0.06
                                                                          -11.0
                                                                           0.35
                                                                           39.3
                                                                           0.59
                                       
                                    IMPROVE
Winter
                                                                            192
                                                                           0.21
                                                                           0.22
                                                                           0.02
                                                                            7.8
                                                                           0.17
                                                                           44.4
                                                                           0.52
                                       
                                       
Spring
                                                                            213
                                                                           0.22
                                                                           0.17
                                                                          -0.04
                                                                          -19.4
                                                                           0.16
                                                                           40.5
                                                                           0.36
                                       
                                       
Summer
                                                                            211
                                                                           0.19
                                                                           0.14
                                                                          -0.05
                                                                          -26.7
                                                                           0.08
                                                                           33.0
                                                                           0.70
                                       
                                       
Fall
                                                                            202
                                                                           0.31
                                                                           0.24
                                                                          -0.07
                                                                          -23.6
                                                                           0.18
                                                                           34.1
                                                                           0.68
                                       
                                       
Annual
                                                                            818
                                                                           0.23
                                                                           0.19
                                                                          -0.04
                                                                          -16.6
                                                                           0.15
                                                                           37.6
                                                                           0.56
                                 Upper Midwest
                                      CSN
Winter
                                                                            278
                                                                           0.34
                                                                           0.54
                                                                           0.21
                                                                           60.4
                                                                           0.45
                                                                           78.7
                                                                           0.55
                                       
                                       
Spring
                                                                            285
                                                                           0.46
                                                                           0.47
                                                                           0.01
                                                                            2.4
                                                                           0.39
                                                                           49.1
                                                                           0.52
                                       
                                       
Summer
                                                                            278
                                                                           0.41
                                                                           0.40
                                                                          -0.01
                                                                           -2.7
                                                                           0.26
                                                                           45.0
                                                                           0.45
                                       
                                       
Fall
                                                                            279
                                                                           0.47
                                                                           0.52
                                                                           0.06
                                                                           12.3
                                                                           0.32
                                                                           47.6
                                                                           0.69
                                       
                                       
Annual
                                                                           1120
                                                                           0.42
                                                                           0.48
                                                                           0.07
                                                                           15.6
                                                                           0.36
                                                                           53.7
                                                                           0.53
                                       
                                    IMPROVE
Winter
                                                                            220
                                                                           0.15
                                                                           0.20
                                                                           0.06
                                                                           40.8
                                                                           0.14
                                                                           56.1
                                                                           0.79
                                       
                                       
Spring
                                                                            239
                                                                           0.19
                                                                           0.17
                                                                          -0.03
                                                                          -14.1
                                                                           0.23
                                                                           44.1
                                                                           0.54
                                       
                                       
Summer
                                                                            237
                                                                           0.18
                                                                           0.14
                                                                          -0.04
                                                                          -21.5
                                                                           0.12
                                                                           42.0
                                                                           0.81
                                       
                                       
Fall
                                                                            240
                                                                           0.20
                                                                           0.19
                                                                          -0.02
                                                                           -8.4
                                                                           0.14
                                                                           42.0
                                                                           0.78
                                       
                                       
Annual
                                                                            936
                                                                           0.18
                                                                           0.17
                                                                          -0.01
                                                                           -3.9
                                                                           0.16
                                                                           45.2
                                                                           0.66
                                     South
                                      CSN
Winter
                                                                            226
                                                                           0.63
                                                                           0.58
                                                                          -0.05
                                                                           -7.6
                                                                           0.35
                                                                           39.7
                                                                           0.60
                                       
                                       
Spring
                                                                            251
                                                                           0.47
                                                                           0.39
                                                                          -0.08
                                                                          -16.6
                                                                           0.27
                                                                           37.9
                                                                           0.54
                                       
                                       
Summer
                                                                            208
                                                                           0.43
                                                                           0.41
                                                                          -0.02
                                                                           -4.9
                                                                           0.30
                                                                           51.2
                                                                           0.36
                                       
                                       
Fall
                                                                            194
                                                                           0.60
                                                                           0.60
                                                                          -0.01
                                                                           -0.9
                                                                           0.37
                                                                           44.3
                                                                           0.49
                                       
                                       
Annual
                                                                            879
                                                                           0.53
                                                                           0.49
                                                                          -0.04
                                                                           -7.7
                                                                           0.32
                                                                           42.6
                                                                           0.55
                                       
                                    IMPROVE
Winter
                                                                            212
                                                                           0.15
                                                                           0.14
                                                                          -0.00
                                                                           -2.1
                                                                           0.11
                                                                           43.2
                                                                           0.68
                                       
                                       
Spring
                                                                            242
                                                                           0.16
                                                                           0.15
                                                                          -0.02
                                                                          -10.1
                                                                           0.23
                                                                           53.6
                                                                           0.61
                                       
                                       
Summer
                                                                            219
                                                                           0.11
                                                                           0.08
                                                                          -0.03
                                                                          -24.9
                                                                           0.07
                                                                           44.6
                                                                           0.63
                                       
                                       
Fall
                                                                            234
                                                                           0.17
                                                                           0.12
                                                                          -0.06
                                                                          -32.0
                                                                           0.10
                                                                           40.6
                                                                           0.70
                                       
                                       
Annual
                                                                            907
                                                                           0.15
                                                                           0.12
                                                                          -0.03
                                                                          -17.5
                                                                           0.14
                                                                           45.7
                                                                           0.63
                                   Southwest
                                      CSN
Winter
                                                                            180
                                                                           0.80
                                                                           0.83
                                                                           0.04
                                                                            4.6
                                                                           0.47
                                                                           44.0
                                                                           0.55
                                       
                                       
Spring
                                                                            194
                                                                           0.30
                                                                           0.44
                                                                           0.14
                                                                           48.7
                                                                           0.27
                                                                           64.3
                                                                           0.66
                                       
                                       
Summer
                                                                            179
                                                                           0.32
                                                                           0.38
                                                                           0.06
                                                                           17.8
                                                                           0.22
                                                                           47.1
                                                                           0.42
                                       
                                       
Fall
                                                                            187
                                                                           0.54
                                                                           0.63
                                                                           0.09
                                                                           15.8
                                                                           0.36
                                                                           49.0
                                                                           0.62
                                       
                                       
Annual
                                                                            740
                                                                           0.49
                                                                           0.57
                                                                           0.08
                                                                           16.9
                                                                           0.34
                                                                           49.1
                                                                           0.66
                                       
                                    IMPROVE
Winter
                                                                            829
                                                                           0.15
                                                                           0.12
                                                                          -0.02
                                                                          -15.1
                                                                           0.17
                                                                           47.3
                                                                           0.86
                                       
                                       
Spring
                                                                            909
                                                                           0.07
                                                                           0.09
                                                                           0.02
                                                                           22.7
                                                                           0.11
                                                                           66.0
                                                                           0.67
                                       
                                       
Summer
                                                                            894
                                                                           0.10
                                                                           0.09
                                                                          -0.01
                                                                          -11.8
                                                                           0.09
                                                                           51.2
                                                                           0.63
                                       
                                       
Fall
                                                                            882
                                                                           0.12
                                                                           0.10
                                                                          -0.02
                                                                          -15.3
                                                                           0.13
                                                                           49.4
                                                                           0.78
                                       
                                       
Annual
                                                                           3514
                                                                           0.11
                                                                           0.10
                                                                          -0.01
                                                                           -7.8
                                                                           0.13
                                                                           52.0
                                                                           0.79
                               N. Rockies & 
                                    Plains
                                      CSN
Winter
                                                                            124
                                                                           0.27
                                                                           0.25
                                                                          -0.02
                                                                           -8.1
                                                                           0.52
                                                                           92.1
                                                                           0.09
                                       
                                       
Spring
                                                                            145
                                                                           0.20
                                                                           0.17
                                                                          -0.03
                                                                          -16.8
                                                                           0.20
                                                                           55.1
                                                                           0.45
                                       
                                       
Summer
                                                                            161
                                                                           0.22
                                                                           0.18
                                                                          -0.04
                                                                          -18.2
                                                                           0.16
                                                                           43.2
                                                                           0.45
                                       
                                       
Fall
                                                                            146
                                                                           0.24
                                                                           0.20
                                                                          -0.05
                                                                          -18.5
                                                                           0.37
                                                                           66.0
                                                                           0.16
                                       
                                       
Annual
                                                                            576
                                                                           0.23
                                                                           0.20
                                                                          -0.04
                                                                          -15.5
                                                                           0.33
                                                                           64.1
                                                                           0.20
                                       
                                    IMPROVE
Winter
                                                                            540
                                                                           0.05
                                                                           0.06
                                                                           0.01
                                                                           18.5
                                                                           0.08
                                                                           78.6
                                                                           0.37
                                       
                                       
Spring
                                                                            573
                                                                           0.07
                                                                           0.07
                                                                          -0.01
                                                                           -6.9
                                                                           0.21
                                                                           77.5
                                                                           0.49
                                       
                                       
Summer
                                                                            601
                                                                           0.10
                                                                           0.14
                                                                           0.03
                                                                           32.5
                                                                           0.42
                                                                           82.1
                                                                           0.27
                                       
                                       
Fall
                                                                            574
                                                                           0.09
                                                                           0.08
                                                                          -0.01
                                                                          -14.4
                                                                           0.14
                                                                           61.3
                                                                           0.27
                                       
                                       
Annual
                                                                           2288
                                                                           0.08
                                                                           0.09
                                                                           0.01
                                                                            8.1
                                                                           0.25
                                                                           74.6
                                                                           0.33
                                   Northwest
                                      CSN
Winter
                                                                            132
                                                                           0.76
                                                                           1.05
                                                                           0.29
                                                                           38.4
                                                                           1.07
                                                                           83.4
                                                                           0.42
                                       
                                       
Spring
                                                                            135
                                                                           0.46
                                                                           1.04
                                                                           0.58
                                                                          126.0
                                                                           1.29
                                                                          146.3
                                                                           0.61
                                       
                                       
Summer
                                                                            129
                                                                           0.41
                                                                           1.11
                                                                           0.70
                                                                          171.2
                                                                           1.19
                                                                          175.7
                                                                           0.49
                                       
                                       
Fall
                                                                            130
                                                                           0.59
                                                                           1.21
                                                                           0.62
                                                                          105.5
                                                                           1.23
                                                                          131.3
                                                                           0.44
                                       
                                       
Annual
                                                                            526
                                                                           0.56
                                                                           1.10
                                                                           0.55
                                                                           98.7
                                                                           1.20
                                                                          126.0
                                                                           0.45
                                       
                                    IMPROVE
Winter
                                                                            425
                                                                           0.08
                                                                           0.13
                                                                           0.04
                                                                           51.8
                                                                           0.32
                                                                          104.5
                                                                           0.79
                                       
                                       
Spring
                                                                            482
                                                                           0.08
                                                                           0.18
                                                                           0.10
                                                                          121.8
                                                                           0.53
                                                                          158.1
                                                                           0.72
                                       
                                       
Summer
                                                                            488
                                                                           0.15
                                                                           0.29
                                                                           0.14
                                                                           90.2
                                                                           0.66
                                                                          153.2
                                                                           0.35
                                       
                                       
Fall
                                                                            471
                                                                           0.12
                                                                           0.25
                                                                           0.13
                                                                          104.2
                                                                           0.56
                                                                          150.3
                                                                           0.69
                                       
                                       
Annual
                                                                           1866
                                                                           0.11
                                                                           0.21
                                                                           0.10
                                                                           93.3
                                                                           0.54
                                                                          144.8
                                                                           0.49
                                     West
                                      CSN
Winter
                                                                            241
                                                                           1.05
                                                                           0.93
                                                                          -0.12
                                                                          -11.4
                                                                           0.56
                                                                           36.9
                                                                           0.61
                                       
                                       
Spring
                                                                            253
                                                                           0.41
                                                                           0.50
                                                                           0.09
                                                                           22.1
                                                                           0.27
                                                                           45.0
                                                                           0.76
                                       
                                       
Summer
                                                                            247
                                                                           0.43
                                                                           0.53
                                                                           0.09
                                                                           21.6
                                                                           0.23
                                                                           38.1
                                                                           0.75
                                       
                                       
Fall
                                                                            235
                                                                           0.67
                                                                           0.76
                                                                           0.09
                                                                           13.9
                                                                           0.37
                                                                           39.8
                                                                           0.67
                                       
                                       
Annual
                                                                            976
                                                                           0.64
                                                                           0.68
                                                                           0.04
                                                                            6.3
                                                                           0.38
                                                                           39.2
                                                                           0.72
                                       
                                    IMPROVE
Winter
                                                                            510
                                                                           0.12
                                                                           0.11
                                                                          -0.01
                                                                           -6.2
                                                                           0.16
                                                                           57.6
                                                                           0.84

Spring
                                                                            546
                                                                           0.08
                                                                           0.09
                                                                           0.02
                                                                           20.5
                                                                           0.09
                                                                           65.8
                                                                           0.74

Summer
                                                                            556
                                                                           0.19
                                                                           0.18
                                                                          -0.01
                                                                           -3.1
                                                                           0.51
                                                                           63.9
                                                                           0.44

Fall
                                                                            527
                                                                           0.15
                                                                           0.16
                                                                           0.01
                                                                            6.4
                                                                           0.20
                                                                           60.4
                                                                           0.68

Annual
                                                                           2139
                                                                           0.13
                                                                           0.14
                                                                           0.00
                                                                            2.4
                                                                           0.29
                                                                           61.9
                                                                           0.55

Table 2A-6	CMAQ Performance Statistics for PM2.5 OC at CSN and IMPROVE Sites in 2016
                                    Region
                                    Network
                                    Season
                                       N
                                     Avg.
                                     Obs.
                                 (g m[-3])
                                     Avg.
                                     Mod.
                                 (g m[-3])
                                      MB
                                 (g m[-3])
                                      NMB
                                      (%)
                                     RMSE
                                 (g m[-3])
                                      NME
                                      (%)
                                       r
                                   Northeast
                                      CSN
Winter
                                                                            672
                                                                           1.81
                                                                           3.25
                                                                           1.45
                                                                           80.2
                                                                           2.61
                                                                           91.5
                                                                           0.67
                                       
                                       
Spring
                                                                            736
                                                                           1.56
                                                                           2.24
                                                                           0.68
                                                                           43.5
                                                                           1.51
                                                                           58.8
                                                                           0.64
                                       
                                       
Summer
                                                                            725
                                                                           1.93
                                                                           2.02
                                                                           0.09
                                                                            4.5
                                                                           0.91
                                                                           33.8
                                                                           0.67
                                       
                                       
Fall
                                                                            725
                                                                           1.84
                                                                           2.67
                                                                           0.84
                                                                           45.7
                                                                           1.76
                                                                           60.6
                                                                           0.69
                                       
                                       
Annual
                                                                           2858
                                                                           1.78
                                                                           2.53
                                                                           0.75
                                                                           42.1
                                                                           1.78
                                                                           60.2
                                                                           0.65
                                       
                                    IMPROVE
Winter
                                                                            373
                                                                           0.75
                                                                           1.64
                                                                           0.89
                                                                          119.3
                                                                           1.32
                                                                          122.4
                                                                           0.81
                                       
                                       
Spring
                                                                            422
                                                                           0.74
                                                                           1.10
                                                                           0.36
                                                                           48.0
                                                                           0.76
                                                                           64.5
                                                                           0.76
                                       
                                       
Summer
                                                                            423
                                                                           1.19
                                                                           1.19
                                                                           0.00
                                                                            0.0
                                                                           0.70
                                                                           37.3
                                                                           0.67
                                       
                                       
Fall
                                                                            406
                                                                           0.93
                                                                           1.33
                                                                           0.40
                                                                           43.6
                                                                           1.18
                                                                           63.8
                                                                           0.66
                                       
                                       
Annual
                                                                           1624
                                                                           0.91
                                                                           1.31
                                                                           0.40
                                                                           44.0
                                                                           1.01
                                                                           66.0
                                                                           0.66
                                   Southeast
                                      CSN
Winter
                                                                            392
                                                                           2.03
                                                                           2.97
                                                                           0.94
                                                                           46.3
                                                                           1.99
                                                                           61.8
                                                                           0.66
                                       
                                       
Spring
                                                                            424
                                                                           2.02
                                                                           2.45
                                                                           0.43
                                                                           21.1
                                                                           1.19
                                                                           42.7
                                                                           0.76
                                       
                                       
Summer
                                                                            388
                                                                           1.92
                                                                           2.33
                                                                           0.42
                                                                           21.8
                                                                           1.01
                                                                           38.5
                                                                           0.72
                                       
                                       
Fall
                                                                            374
                                                                           2.78
                                                                           3.06
                                                                           0.28
                                                                           10.1
                                                                           2.67
                                                                           45.3
                                                                           0.58
                                       
                                       
Annual
                                                                           1578
                                                                           2.18
                                                                           2.70
                                                                           0.52
                                                                           23.8
                                                                           1.82
                                                                           47.0
                                                                           0.59
                                       
                                    IMPROVE
Winter
                                                                            376
                                                                           1.21
                                                                           1.78
                                                                           0.57
                                                                           46.9
                                                                           3.66
                                                                           82.1
                                                                           0.21
                                       
                                       
Spring
                                                                            416
                                                                           4.04
                                                                           1.71
                                                                          -2.33
                                                                          -57.6
                                                                          40.44
                                                                           81.9
                                                                           0.15
                                       
                                       
Summer
                                                                            425
                                                                           1.56
                                                                           1.42
                                                                          -0.14
                                                                           -9.1
                                                                           2.62
                                                                           42.9
                                                                           0.23
                                       
                                       
Fall
                                                                            395
                                                                           2.03
                                                                           1.99
                                                                          -0.05
                                                                           -2.4
                                                                           2.27
                                                                           45.6
                                                                           0.58
                                       
                                       
Annual
                                                                           1612
                                                                           2.23
                                                                           1.72
                                                                          -0.52
                                                                          -23.2
                                                                          20.69
                                                                           66.6
                                                                           0.10
                                  Ohio Valley
                                      CSN
Winter
                                                                            498
                                                                           1.61
                                                                           2.59
                                                                           0.98
                                                                           61.1
                                                                           1.76
                                                                           72.6
                                                                           0.62
                                       
                                       
Spring
                                                                            548
                                                                           1.61
                                                                           1.95
                                                                           0.34
                                                                           20.9
                                                                           1.23
                                                                           47.8
                                                                           0.58
                                       
                                       
Summer
                                                                            523
                                                                           1.88
                                                                           1.91
                                                                           0.03
                                                                            1.5
                                                                           0.85
                                                                           32.8
                                                                           0.56
                                       
                                       
Fall
                                                                            523
                                                                           2.47
                                                                           2.76
                                                                           0.29
                                                                           11.7
                                                                           1.87
                                                                           39.5
                                                                           0.70
                                       
                                       
Annual
                                                                           2092
                                                                           1.89
                                                                           2.30
                                                                           0.40
                                                                           21.2
                                                                           1.48
                                                                           46.4
                                                                           0.64
                                       
                                    IMPROVE
Winter
                                                                            192
                                                                           0.96
                                                                           1.64
                                                                           0.68
                                                                           70.4
                                                                           2.66
                                                                           96.2
                                                                           0.29
                                       
                                       
Spring
                                                                            213
                                                                           1.12
                                                                           1.49
                                                                           0.37
                                                                           33.0
                                                                           3.23
                                                                           66.4
                                                                           0.20
                                       
                                       
Summer
                                                                            211
                                                                           1.33
                                                                           1.28
                                                                          -0.05
                                                                           -4.0
                                                                           0.59
                                                                           33.3
                                                                           0.71
                                       
                                       
Fall
                                                                            202
                                                                           1.84
                                                                           2.02
                                                                           0.18
                                                                            9.5
                                                                           2.05
                                                                           50.4
                                                                           0.60
                                       
                                       
Annual
                                                                            818
                                                                           1.32
                                                                           1.60
                                                                           0.29
                                                                           21.7
                                                                           2.34
                                                                           57.4
                                                                           0.34
                                 Upper Midwest
                                      CSN
Winter
                                                                            278
                                                                           1.18
                                                                           2.73
                                                                           1.55
                                                                          132.2
                                                                           2.54
                                                                          134.8
                                                                           0.55
                                       
                                       
Spring
                                                                            285
                                                                           1.56
                                                                           2.22
                                                                           0.66
                                                                           42.1
                                                                           2.08
                                                                           72.2
                                                                           0.38
                                       
                                       
Summer
                                                                            278
                                                                           1.64
                                                                           1.79
                                                                           0.15
                                                                            8.8
                                                                           0.94
                                                                           38.4
                                                                           0.49
                                       
                                       
Fall
                                                                            279
                                                                           1.58
                                                                           2.21
                                                                           0.64
                                                                           40.4
                                                                           1.41
                                                                           55.5
                                                                           0.74
                                       
                                       
Annual
                                                                           1120
                                                                           1.49
                                                                           2.24
                                                                           0.75
                                                                           50.2
                                                                           1.85
                                                                           70.8
                                                                           0.44
                                       
                                    IMPROVE
Winter
                                                                            220
                                                                           0.60
                                                                           1.25
                                                                           0.65
                                                                          107.6
                                                                           1.11
                                                                          111.6
                                                                           0.70
                                       
                                       
Spring
                                                                            239
                                                                           0.90
                                                                           1.09
                                                                           0.19
                                                                           20.5
                                                                           1.58
                                                                           70.9
                                                                           0.34
                                       
                                       
Summer
                                                                            237
                                                                           1.18
                                                                           0.92
                                                                          -0.26
                                                                          -21.8
                                                                           0.58
                                                                           38.2
                                                                           0.54
                                       
                                       
Fall
                                                                            240
                                                                           0.90
                                                                           1.02
                                                                           0.12
                                                                           13.6
                                                                           0.72
                                                                           46.4
                                                                           0.69
                                       
                                       
Annual
                                                                            936
                                                                           0.90
                                                                           1.07
                                                                           0.17
                                                                           18.4
                                                                           1.07
                                                                           60.2
                                                                           0.42
                                     South
                                      CSN
Winter
                                                                            226
                                                                           2.19
                                                                           2.86
                                                                           0.67
                                                                           30.5
                                                                           2.08
                                                                           64.4
                                                                           0.55
                                       
                                       
Spring
                                                                            251
                                                                           1.57
                                                                           1.90
                                                                           0.33
                                                                           21.2
                                                                           1.15
                                                                           52.5
                                                                           0.55
                                       
                                       
Summer
                                                                            208
                                                                           1.68
                                                                           2.07
                                                                           0.39
                                                                           23.3
                                                                           1.45
                                                                           56.0
                                                                           0.55
                                       
                                       
Fall
                                                                            194
                                                                           2.31
                                                                           3.08
                                                                           0.77
                                                                           33.6
                                                                           2.62
                                                                           59.5
                                                                           0.58
                                       
                                       
Annual
                                                                            879
                                                                           1.92
                                                                           2.45
                                                                           0.53
                                                                           27.6
                                                                           1.87
                                                                           58.6
                                                                           0.57
                                       
                                    IMPROVE
Winter
                                                                            212
                                                                           0.74
                                                                           1.10
                                                                           0.36
                                                                           48.7
                                                                           1.25
                                                                           69.2
                                                                           0.63
                                       
                                       
Spring
                                                                            242
                                                                           1.01
                                                                           1.04
                                                                           0.02
                                                                            2.4
                                                                           1.76
                                                                           61.7
                                                                           0.51
                                       
                                       
Summer
                                                                            219
                                                                           1.09
                                                                           0.88
                                                                          -0.21
                                                                          -19.4
                                                                           0.67
                                                                           46.2
                                                                           0.73
                                       
                                       
Fall
                                                                            234
                                                                           1.11
                                                                           0.97
                                                                          -0.14
                                                                          -12.3
                                                                           0.63
                                                                           40.2
                                                                           0.73
                                       
                                       
Annual
                                                                            907
                                                                           0.99
                                                                           1.00
                                                                           0.00
                                                                            0.4
                                                                           1.19
                                                                           52.7
                                                                           0.52
                                   Southwest
                                      CSN
Winter
                                                                            180
                                                                           2.17
                                                                           3.03
                                                                           0.86
                                                                           39.5
                                                                           2.53
                                                                           74.8
                                                                           0.33
                                       
                                       
Spring
                                                                            194
                                                                           0.92
                                                                           1.49
                                                                           0.57
                                                                           62.2
                                                                           1.27
                                                                           83.2
                                                                           0.37
                                       
                                       
Summer
                                                                            179
                                                                           1.47
                                                                           1.38
                                                                          -0.09
                                                                           -6.1
                                                                           0.84
                                                                           37.9
                                                                           0.43
                                       
                                       
Fall
                                                                            187
                                                                           1.53
                                                                           2.02
                                                                           0.49
                                                                           32.1
                                                                           1.40
                                                                           67.9
                                                                           0.47
                                       
                                       
Annual
                                                                            740
                                                                           1.51
                                                                           1.97
                                                                           0.46
                                                                           30.5
                                                                           1.63
                                                                           65.7
                                                                           0.43
                                       
                                    IMPROVE
Winter
                                                                            829
                                                                           0.52
                                                                           0.50
                                                                          -0.02
                                                                           -4.3
                                                                           0.80
                                                                           48.1
                                                                           0.77
                                       
                                       
Spring
                                                                            909
                                                                           0.42
                                                                           0.46
                                                                           0.04
                                                                            8.5
                                                                           0.65
                                                                           55.6
                                                                           0.45
                                       
                                       
Summer
                                                                            894
                                                                           0.86
                                                                           0.62
                                                                          -0.24
                                                                          -27.6
                                                                           0.76
                                                                           50.4
                                                                           0.53
                                       
                                       
Fall
                                                                            882
                                                                           0.60
                                                                           0.50
                                                                          -0.10
                                                                          -16.2
                                                                           0.55
                                                                           46.5
                                                                           0.66
                                       
                                       
Annual
                                                                           3514
                                                                           0.60
                                                                           0.52
                                                                          -0.08
                                                                          -13.4
                                                                           0.70
                                                                           49.9
                                                                           0.62
                               N. Rockies & 
                                    Plains
                                      CSN
Winter
                                                                            124
                                                                           1.05
                                                                           1.10
                                                                           0.05
                                                                            4.5
                                                                           1.93
                                                                           95.2
                                                                           0.12
                                       
                                       
Spring
                                                                            145
                                                                           0.87
                                                                           0.75
                                                                          -0.12
                                                                          -13.4
                                                                           0.76
                                                                           54.9
                                                                           0.48
                                       
                                       
Summer
                                                                            161
                                                                           1.45
                                                                           0.87
                                                                          -0.58
                                                                          -40.0
                                                                           1.05
                                                                           47.2
                                                                           0.49
                                       
                                       
Fall
                                                                            146
                                                                           1.01
                                                                           0.77
                                                                          -0.24
                                                                          -23.6
                                                                           1.04
                                                                           52.0
                                                                           0.23
                                       
                                       
Annual
                                                                            576
                                                                           1.11
                                                                           0.87
                                                                          -0.24
                                                                          -21.9
                                                                           1.24
                                                                           59.6
                                                                           0.25
                                       
                                    IMPROVE
Winter
                                                                            540
                                                                           0.30
                                                                           0.34
                                                                           0.05
                                                                           15.5
                                                                           0.42
                                                                           70.0
                                                                           0.36
                                       
                                       
Spring
                                                                            573
                                                                           0.59
                                                                           0.47
                                                                          -0.12
                                                                          -20.9
                                                                           1.33
                                                                           63.6
                                                                           0.55
                                       
                                       
Summer
                                                                            601
                                                                           1.22
                                                                           1.03
                                                                          -0.20
                                                                          -16.0
                                                                           3.17
                                                                           58.2
                                                                           0.25
                                       
                                       
Fall
                                                                            574
                                                                           0.63
                                                                           0.49
                                                                          -0.14
                                                                          -22.5
                                                                           1.05
                                                                           60.6
                                                                           0.23
                                       
                                       
Annual
                                                                           2288
                                                                           0.70
                                                                           0.59
                                                                          -0.11
                                                                          -15.3
                                                                           1.84
                                                                           61.1
                                                                           0.34
                                   Northwest
                                      CSN
Winter
                                                                            132
                                                                           2.54
                                                                           4.33
                                                                           1.80
                                                                           70.9
                                                                           4.33
                                                                           98.1
                                                                           0.45
                                       
                                       
Spring
                                                                            135
                                                                           1.43
                                                                           3.62
                                                                           2.19
                                                                          152.9
                                                                           4.59
                                                                          160.7
                                                                           0.58
                                       
                                       
Summer
                                                                            129
                                                                           1.55
                                                                           3.83
                                                                           2.28
                                                                          147.0
                                                                           3.58
                                                                          153.7
                                                                           0.48
                                       
                                       
Fall
                                                                            130
                                                                           1.99
                                                                           3.90
                                                                           1.92
                                                                           96.5
                                                                           3.53
                                                                          116.0
                                                                           0.48
                                       
                                       
Annual
                                                                            526
                                                                           1.88
                                                                           3.92
                                                                           2.05
                                                                          109.1
                                                                           4.04
                                                                          126.3
                                                                           0.45
                                       
                                    IMPROVE
Winter
                                                                            425
                                                                           0.36
                                                                           0.61
                                                                           0.25
                                                                           69.1
                                                                           1.54
                                                                          128.6
                                                                           0.57
                                       
                                       
Spring
                                                                            482
                                                                           0.54
                                                                           0.82
                                                                           0.28
                                                                           51.8
                                                                           1.81
                                                                           93.3
                                                                           0.53
                                       
                                       
Summer
                                                                            488
                                                                           1.32
                                                                           1.57
                                                                           0.24
                                                                           18.5
                                                                           2.94
                                                                           83.3
                                                                           0.47
                                       
                                       
Fall
                                                                            471
                                                                           0.77
                                                                           1.28
                                                                           0.51
                                                                           66.8
                                                                           2.43
                                                                          116.9
                                                                           0.55
                                       
                                       
Annual
                                                                           1866
                                                                           0.76
                                                                           1.08
                                                                           0.32
                                                                           42.3
                                                                           2.26
                                                                           98.6
                                                                           0.44
                                     West
                                      CSN
Winter
                                                                            241
                                                                           3.61
                                                                           4.10
                                                                           0.49
                                                                           13.6
                                                                           2.89
                                                                           48.9
                                                                           0.58
                                       
                                       
Spring
                                                                            253
                                                                           1.52
                                                                           1.85
                                                                           0.32
                                                                           21.3
                                                                           1.10
                                                                           44.5
                                                                           0.64
                                       
                                       
Summer
                                                                            247
                                                                           2.40
                                                                           2.23
                                                                          -0.17
                                                                           -7.2
                                                                           1.44
                                                                           36.0
                                                                           0.51
                                       
                                       
Fall
                                                                            235
                                                                           2.77
                                                                           3.10
                                                                           0.33
                                                                           11.9
                                                                           1.96
                                                                           43.7
                                                                           0.62
                                       
                                       
Annual
                                                                            976
                                                                           2.56
                                                                           2.80
                                                                           0.24
                                                                            9.4
                                                                           1.96
                                                                           43.8
                                                                           0.63
                                       
                                    IMPROVE
Winter
                                                                            510
                                                                           0.59
                                                                           0.52
                                                                          -0.07
                                                                          -12.0
                                                                           0.60
                                                                           50.5
                                                                           0.87

Spring
                                                                            546
                                                                           0.62
                                                                           0.51
                                                                          -0.11
                                                                          -17.5
                                                                           0.48
                                                                           46.7
                                                                           0.61

Summer
                                                                            556
                                                                           1.72
                                                                           1.39
                                                                          -0.33
                                                                          -19.2
                                                                           2.77
                                                                           52.4
                                                                           0.43

Fall
                                                                            527
                                                                           1.07
                                                                           1.00
                                                                          -0.07
                                                                           -6.7
                                                                           1.22
                                                                           50.0
                                                                           0.64

Annual
                                                                           2139
                                                                           1.01
                                                                           0.86
                                                                          -0.15
                                                                          -14.7
                                                                           1.58
                                                                           50.6
                                                                           0.54

      
 2A.2	Projecting PM2.5 DVs to 2032
PM2.5 DVs were projected to 2032 using air quality modeling to inform estimates of the emission reductions needed to meet standards beyond the reductions expected to occur due to finalized rules. The projections were performed by pairing the 2016 CMAQ simulation with a corresponding CMAQ simulation based on emissions representative of 2032. The 2032 emissions case accounts for factors including emission reductions between 2016 and 2032 from `on-the-books' rules and has been described in detail previously (USEPA, 2022). Other than differences in the emissions inputs, all aspects of the 2032 CMAQ modeling were specified identical to the 2016 modeling. These aspects include the meteorology, boundary conditions, the 12-km modeling domain, and the model configuration.
To predict the influence of the emission reductions between 2016 and 2032 on PM2.5 DVs, PM2.5 relative response factors (RRFs) were calculated using the CMAQ results to project monitoring data to 2032. RRFs are the ratios of modeled PM2.5 species concentrations in the future year (2032) to the base year (2016). RRFs are used in projecting air quality to help mitigate the influence of systematic biases in model predictions (e.g., systematic biases in the 2016 and 2032 modeling may partially cancel in the ratio) (Cohan and Chen, 2014, NRC, 2004, USEPA, 2018). RRFs are calculated for each PM2.5 component (i.e., sulfate, nitrate, organic carbon, elemental carbon, crustal material, and ammonium). The annual and 24-hour PM2.5 DVs for the future year are calculated by applying the species-specific RRFs to ambient PM2.5 concentrations from the PM2.5 monitoring network, which are disaggregated into species concentrations by applying the SANDWICH method (Frank, 2006) and through interpolation of PM2.5 species data from the CSN and IMPROVE monitoring networks. Details on the PM2.5 projection method using RRFs are provided in the user's guide for the predecessor to the SMAT-CE software (Abt, 2014). The RRF method for calculating future-year PM2.5 annual and 24-hour PM2.5 DVs was implemented here using the Software for Modeled Attainment Test-Community Edition (SMAT-CE) version 1.8 (USEPA, 2018, Wang et al., 2015). 
    2A.2.1	Monitoring Data for PM2.5 Projections
PM2.5 DVs were projected using ambient PM2.5 measurements from the 2014-2018 period centered on the 2016 CMAQ modeling period. PM2.5 species measurements from the IMPROVE and CSN networks during 2015 - 2017 were used to disaggregate the measured total PM2.5 concentrations into components for the RRF calculations. As in the 2012 PM2.5 NAAQS RIA (USEPA, 2012a), limited exclusion of wildfire and fireworks influence on PM2.5 concentrations was applied to the 2014-2018 PM2.5 monitoring data in addition to exclusion of EPA-concurred exceptional events. Monitoring data were evaluated (i.e., screened) for potential wildfire and fireworks influence because PM2.5 concentrations may be influenced by atypical, extreme, or unrepresentative events such as wildfires or fireworks that may be appropriate for exclusion as described in EPA's memorandum Additional Methods, Determinations, and Analyses to Modify Air Quality Data Beyond Exceptional Events  (USEPA, 2019a). Due to the challenges in identifying wildfire influence on monitored concentrations, only limited screening of major wildfire influence is possible here, and wildfire impacts on concentrations likely persists in the screened data.
 The steps in implementing the limited screening of major wildfire and fireworks influence on PM2.5 concentrations are as follows: 
 An extreme value cutoff of 61 ug m[-3] was identified based the 99.9[th] percentile value from all daily PM2.5 concentrations across all sites in the long-term AQS observations (2002-2018).
 Specific states and months were screened for instances of monitors exceeding the extreme value cutoff to identify potential periods of interest. States included for screening were CA, WA, OR, MT, ID, and CO. These states were selected due to the prevalence of wildfire in the western U.S. and the potential for NAAQS exceedances in these areas. States in the southwest were not included in part due to challenges in distinguishing wildfire influence from dust events. Months included were June-October (while November can be a high fire month for parts of the western U.S., it becomes more difficult to distinguish wildfire PM2.5 from residential wood smoke and other anthropogenic sources during the late fall). 
 For periods flagged under the previous step, the presence of visible wildfire smoke was corroborated using satellite imagery from NASA's Worldview platform (https://worldview.earthdata.nasa.gov) for the dates and geographic location identified. If corroboration with satellite imagery was not possible, the episode was not included. Timeseries for individual sites flagged were also examined to confirm PM2.5 enhancements temporally consistent with the wildfire events identified (Figures 2A-16 to 2A-25).
 For wildfire periods confirmed with satellite imagery, all concentrations above the extreme value cutoff of 61 ug m[-3] occurring during the identified wildfire episode window at impacted sites were removed. 
 In addition to the evaluation criteria above, data corresponding to the Camp Fire (northern CA during November 2018) and the Appalachian Fires (NC, TN, GA during November 2016) were evaluated for exclusion if concentrations exceeded the extreme value threshold of 61 mg m[-3]. These large fire episodes show obvious impacts across multiple monitors and were clearly documented with satellite imagery (Figures 2A-6 to and 2A-15). 
 In addition to the limited exclusion of major wildfire influence, data were evaluated to identify days for potential exclusion due to the influence of isolated fireworks events on PM2.5 concentrations. The 99.9[th] percentile value of 61 ug m[-3] was applied as the cutoff across all sites for New Year's Eve and the Fourth of July. 
A full list of episodes and counties that were evaluated for potential exclusion of monitor data due to influence from wildfire and fireworks is shown in Table 2A-7. Example satellite imagery and timeseries of PM2.5 at impacted monitors for each episode are shown in Figures 2A-6 to 2A-14. The flagged day-site combinations represent 0.4% (767/200,201) of all possible day-site combinations for those sites. Not all days flagged for potential fire influence were excluded only those above the 61 ug m[-3] threshold.
      

Table 2A-7	Wildfire Episodes and Counties Where Data Were Screened for Exclusion if PM2.5 Concentrations Exceeded the Extreme Value Threshold of 61 ug m[-3]
Episode
Dates
Impacted County
State
Camp Fire
Nov. 8-20, 2018
Alameda
CA

Stanislaus
CA

San Joaquin
CA

Sonoma
CA

Butte
CA

Contra Costa
CA

Colusa
CA

Fresno
CA

Mendocino
CA

Sacramento
CA

Napa
CA

Solano
CA

Placer
CA

San Francisco
CA

Marin
CA

Yolo
CA

Tehama
CA

Lake
CA

Santa Clara
CA

Santa Cruz
CA

Nevada
CA

Kings
CA

Merced
CA

San Mateo
CA

Madera
CA

Monterey
CA
North Bay/Wine Country Fires
Oct. 8-20, 2017
Napa
CA

San Joaquin
CA

Mendocino
CA

Solano
CA

Contra Costa
CA

Lake
CA

Sonoma
CA

Marin
CA

Alameda
CA

Nevada
CA

Mendocino
CA
Pacific Northwest/northern CA Fires of 2017
Aug. 1- Sept. 13, 2017
Benewah
ID

Lemhi
ID

Shoshone
ID

Ada
ID

Canyon
ID

Bannock
ID

Jackson
OR

Lane
OR

Josephine
OR

Crook
OR

Klamath
OR

Harney
OR

Flathead
MT

Silver Bow
MT

Lewis and Clark
MT

Powder River
MT

Fergus
MT

Missoula
MT

Ravalli
MT

Lincoln
MT

Yakima
WA

Spokane
WA

Clark
WA

King
WA

Pierce
WA

Okanogan
WA

Snohomish
WA

Shasta
CA

Tehama
CA

Sonoma
CA

Siskiyou
CA
Washington/Oregon Fires of 2018
July 14-Aug. 25, 2018
Spokane
WA

Okanogan
WA

Skagit
WA

Whatcom
WA

Snohomish
WA

Kitsap
WA

King
WA

Clark
WA

Pierce
WA

Yakima
WA

Jackson
OR

Lake
OR

Harney
OR

Klamath
OR

Josephine
OR

Lane
OR

Siskiyou
CA
Montana Fires of 2018
Aug. 13-Aug. 28, 2018
Lincoln
MT

Missoula
MT

Lewis and Clark
MT

Yellowstone
MT

Fergus
MT

Flathead
MT

Shoshone
ID
Montana/Washington/Idaho Fires of 2015
Aug. 15-Aug. 30, 2015
Missoula
MT

Ravalli
MT

Lincoln
MT

Missoula
MT

Flathead
MT

Lewis and Clark
MT

Powder River
MT

Silver Bow
MT

Fergus
MT

Lemhi
ID

Shoshone
ID

Bannock
ID

Clark
WA
416/Burro Fire Complex
June 8-13 2018
La Plata
CO
Butte Fire
Sept. 11-14, 2015
Calaveras
CA

Placer
CA
Carr/Mendocino/Ferguson Fires
July 28-Aug. 18, 2018
Inyo
CA

Mono
CA

Shasta
CA

Siskiyou
CA

Calaveras
CA

Tehama
CA

Lake
CA

Fresno
CA

Tulare
CA

Butte
CA

Nevada
CA
Appalachian Fires
Nov. 7-24, 2016
Hamilton
TN

Knox
TN

Loudon
TN

Roane
TN

Blount
TN

Swain
NC

Mitchell
NC

Buncombe
NC

Jackson
NC

Walker
GA

Clarke
GA

Richmond
GA

Hall
GA

Greenville
SC

Richland
SC

Edgefield
SC

Lexington
SC

Charleston
SC
Fireworks
July 4-5 and Dec. 31-Jan. 1 (all years)
Weber
UT

Pierce
WA

Snohomish
WA

Clark
NV

St. Louis City
MO

Macomb
MI

Marion
IN

Lake
IN

Allen
IN

Cook
IL

La Plata
CO

Stanislaus
CA

San Joaquin
CA

San Bernardino
CA

Riverside
CA

Merced
CA

Madera
CA

Los Angeles
CA

Kings
CA

Kern
CA

Inyo
CA

Imperial
CA

Fresno
CA

Santa Cruz
AZ

Maricopa
AZ

                                       
Figure 2A-6	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from the Camp Fire on 11/10/2018
                                       
Figure 2A-7	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from the North Bay/Wine Country Fires on 10/09/2017
                                       
Figure 2A-8	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from Fires Across the Pacific Northwest/Northern California on 08/29/2017
                                       
Figure 2A-9 	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from Fires in Washington and Oregon on 08/09/2018
                                       
Figure 2A-10	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from Fires in Montana on 08/19/2018
                                       
Figure 2A-11	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from Fires in Montana, Washington and Idaho on 08/22/2015
                                       
Figure 2A-12	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from the 416/Burro Complex Fires on 06/10/2018
                                       
Figure 2A-13	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from the Butte Fire on 09/11/2015
                                       
Figure 2A-14	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from the Carr/Mendocino/Ferguson Fires on 08/04/2018
                                       
Figure 2A-15	Visible Satellite Imagery from NASA's Worldview Platform Showing Smoke from Fires in the Appalachians on 11/10/2016
                                       
Figure 2A-16	Daily PM2.5 (in ug m[-3]) from a Subset of Monitors Impacted by the Camp Fire in November 2018
Note: Bottom axis shows day in 2018. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.   
                                       
Figure 2A-17	Daily PM2.5 (in ug m[-3]) from a Subset of Monitors Impacted by the North Bay/Wine Country Fires in October 2017 
Note: Bottom axis shows day in 2017. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.
                                       
Figure 2A-18	Daily PM2.5 (in ug m[-3]) from a Subset of Monitors Impacted by Fires in the Pacific Northwest/Northern California in August-September 2017 
Note: Bottom axis shows day in 2017. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.  
                                       
Figure 2A-19	Daily PM2.5 (in ug m[-3]) from a Subset of Monitors Impacted by Fires in Washington and Oregon in July-August 2018
Note: Bottom axis shows day in 2018. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.
                                       
Figure 2A-20 	Daily PM2.5 (in ug m[-3]) from the Monitors Impacted by Fires and Smoke in Montana in August 2018
Note: Bottom axis shows day in 2018. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.
                                       
Figure 2A-21 	Daily PM2.5 (in ug m[-3]) from a Subset of Monitors Impacted by Fires in Montana, Washington and Idaho in August 2015
Note: Bottom axis shows day in 2015. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.
                                       
Figure 2A-22	Daily PM2.5 (in ug m[-3]) from the Monitor in Plata, CO Impacted by the 416/Burro Fire Complex in June 2018
Note: Bottom axis shows day in 2018. Red line indicates extreme value threshold of 61 ug m[-3] used for screening. 
                                       
Figure 2A-23	Daily PM2.5 (in ug m[-3]) from the Two monitors Impacted by the Butte Fire in September 2015 
Note: Bottom axis shows day in 2015. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.
                                       
Figure 2A-24	Daily PM2.5 (in ug m[-3]) from a Subset of Monitors Impacted by the Carr/Mendocino/Ferguson Fires in August 2018
Note: Bottom axis shows day in 2018. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.
                                       
Figure 2A-25 	Daily PM2.5 (in ug m[-3]) from a Subset of Monitors Impacted by Fires in the Appalachians in November 2016
Note: Bottom axis shows day in 2016. Red line indicates extreme value threshold of 61 ug m[-3] used for screening.

    2A.2.2	Future-Year PM2.5 Design Values
PM2.5 DVs were projected to 2032 using air quality modeling as described above and compared with the existing standard combination, 12/35. Counties with projected 2032 PM2.5 DVs exceeding the existing standards are shown in Figure 2A-26. Counties that exceed only the 24-hour standard are in northern California, Oregon, Washington, Idaho, Utah, and Montana. Elevated PM2.5 episodically occurs in winter in these areas due to meteorological temperature inversions that concentrate PM2.5 in shallow layers, especially in mountainous terrain. In California, multiple counties exceed both the annual and 24-hour standards and three counties (Los Angeles, San Bernardino, and Imperial) exceed only the annual standard. Los Angeles and San Bernardino are in the South Coast Air Basin along with Riverside County, which exceeds both the annual and 24-hour standard.  

                                       
Figure 2A-26	Counties with Projected 2032 PM2.5 DVs that Exceed the 24-Hour (24-hr Only), Annual (Annual Only) or Both the 24-Hour and Annual (Both) Standards for the Combination of Existing Standards (12/35)

As described below in section 2A.3.4, PM2.5 DVs for 2032 were adjusted to correspond with just meeting the existing standard level to form the 12/35 analytical baseline used in estimating the incremental costs and benefits of meeting the alternative standards relative to the existing standards. The county exceedances of the alternative standards in the 12/35 analytical baseline are shown in Figure 2A-27. Since the PM2.5 DVs have been adjusted to meet the 24-hour standard level of 35 g m[-3] in the analytical baseline, there are no exceedances of the 24-hour standard for the cases of 10/35, 9/35, and 8/35. For the 10/35 case, six counties in the east, three in the NW, and fifteen in California have annual PM2.5 DVs greater than 10 g m[-3] in the 12/35 analytical baseline. For the 10/30 case, twenty-three counties have 24-hr DVs greater than 30 g m-3 and annual DVs less than 10 g m[-3], and eleven counties exceed both the 24-hr and annual standards. For the 9/35 case, twenty-two counties exceed the annual standard in the eastern US, compared with six for the 10/35 and 10/30 cases. The total number of counties exceeding the standards increases from 51 to 141 when moving from 9/35 to 8/35. In Table 2A-8, PM2.5 DVs are shown for the 2032 projections and 12/35 analytical baseline for sites with the highest annual and 24-hour PM2.5 DVs in counties with 2032 DVs that exceed an annual standard 8 g m[-3] or a 24-hour standard of 30 g m[-3].  
                                       
                                       
Figure 2A-27	Counties with PM2.5 DVs in the 12/35 Analytical Baseline that Exceed the 24-Hour (24-hr Only), Annual (Annual Only) or Both the 24-Hour and Annual (Both) Standards for the Combination of Existing Standards

Table 2A-8	PM2.5 DVs for 2032 Projection and 12/35 Analytical Baseline for the Highest DVs in the County for Counties with Annual 2032 DVs Greater 8 g m[-3] or 24-hour 2032 DVs Greater than 30 g m[-3]
State
County
                                    Annual
                                    2032 DV
                                 (g m[-3])
                                    24-hour
                                    2032 DV
                                 (g m[-3])
                                    Annual
                                   12/35 DV
                                 (g m[-3])
                                    24-hour
                                   12/35 DV
                                 (g m[-3])
AL
Jefferson
                                     9.86
                                     20.1
                                     9.86
                                     20.1
AL
Talladega
                                     8.20
                                     16.3
                                     8.20
                                     16.3
AZ
Maricopa
                                     9.47
                                     26.7
                                     9.47
                                     26.7
AZ
Pinal[a]
                                     8.16
                                     34.2
                                     8.16
                                     34.2
AZ
Santa Cruz
                                     8.99
                                     26.5
                                     8.99
                                     26.5
AR
Pulaski
                                     8.99
                                     19.3
                                     8.99
                                     19.3
AR
Union
                                     8.12
                                     17.0
                                     8.12
                                     17.0
CA
Alameda
                                     10.14
                                     25.4
                                     10.14
                                     25.4
CA
Butte
                                     8.28
                                     27.2
                                     8.28
                                     27.2
CA
Contra Costa
                                     9.16
                                     25.1
                                     9.16
                                     25.1
CA
Fresno
                                     13.34
                                     50.8
                                     11.43
                                     35.4
CA
Imperial
                                     12.45
                                     32.4
                                     12.04
                                     31.5
CA
Kern
                                     16.20
                                     57.2
                                     12.04
                                     32.5
CA
Kings
                                     15.27
                                     48.2
                                     12.04
                                     28.4
CA
Los Angeles
                                     12.73
                                     34.9
                                     12.04
                                     31.1
CA
Madera
                                     12.13
                                     39.8
                                     10.60
                                     31.1
CA
Marin
                                     8.18
                                     23.4
                                     8.18
                                     23.4
CA
Merced
                                     11.88
                                     36.3
                                     10.79
                                     29.1
CA
Napa
                                     10.09
                                     25.7
                                     10.09
                                     25.7
CA
Orange
                                     7.79
                                     31.5
                                     7.47
                                     28.5
CA
Plumas
                                     14.52
                                     47.8
                                     10.60
                                     35.4
CA
Riverside
                                     14.10
                                     39.9
                                     12.04
                                     33.1
CA
Sacramento
                                     9.29
                                     31.0
                                     9.29
                                     31.0
CA
San Bernardino
                                     14.96
                                     35.0
                                     12.04
                                     26.3
CA
San Diego
                                     9.16
                                     22.3
                                     9.16
                                     22.3
CA
San Joaquin
                                     12.01
                                     35.7
                                     10.08
                                     29.1
CA
San Luis Obispo
                                     9.63
                                     25.1
                                     9.63
                                     25.1
CA
Santa Clara
                                     9.56
                                     26.0
                                     9.56
                                     26.0
CA
Siskiyou
                                     7.77
                                     34.8
                                     7.77
                                     34.8
CA
Solano
                                     9.04
                                     24.7
                                     9.04
                                     24.7
CA
Stanislaus
                                     12.43
                                     38.7
                                     11.08
                                     29.8
CA
Sutter
                                     8.82
                                     27.6
                                     8.82
                                     27.6
CA
Tulare
                                     14.66
                                     46.5
                                     12.04
                                     25.3
CA
Ventura
                                     9.23
                                     33.5
                                     9.23
                                     33.5
CO
Denver
                                     9.04
                                     24.1
                                     9.04
                                     24.1
CO
Weld
                                     8.14
                                     24.9
                                     8.14
                                     24.9
DE
New Castle
                                     8.14
                                     21.4
                                     8.14
                                     21.4
DC
District of Columbia
                                     8.21
                                     19.8
                                     8.21
                                     19.8
GA
Bibb
                                     8.80
                                     18.3
                                     8.80
                                     18.3
GA
Clayton
                                     8.57
                                     17.2
                                     8.57
                                     17.2
GA
Cobb
                                     8.09
                                     16.6
                                     8.09
                                     16.6
GA
DeKalb
                                     8.08
                                     18.2
                                     8.08
                                     18.2
GA
Dougherty
                                     8.38
                                     21.3
                                     8.38
                                     21.3
GA
Floyd
                                     8.72
                                     17.3
                                     8.72
                                     17.3
GA
Fulton
                                     9.46
                                     20.4
                                     9.46
                                     20.4
GA
Gwinnett
                                     8.06
                                     18.7
                                     8.06
                                     18.7
GA
Muscogee
                                     8.68
                                     27.3
                                     8.68
                                     27.3
GA
Richmond
                                     8.54
                                     21.0
                                     8.54
                                     21.0
GA
Wilkinson
                                     8.97
                                     19.2
                                     8.97
                                     19.2
ID
Benewah
                                     9.61
                                     35.2
                                     9.61
                                     35.2
ID
Canyon
                                     8.86
                                     31.4
                                     8.86
                                     31.4
ID
Lemhi
                                     11.03
                                     39.4
                                     10.05
                                     35.4
ID
Shoshone
                                     11.04
                                     36.6
                                     10.75
                                     35.4
IL
Cook
                                     9.43
                                     20.7
                                     9.43
                                     20.7
IL
Madison
                                     9.03
                                     19.0
                                     9.03
                                     19.0
IL
Saint Clair
                                     8.99
                                     17.6
                                     8.99
                                     17.6
IN
Allen
                                     8.10
                                     19.6
                                     8.10
                                     19.6
IN
Clark
                                     8.58
                                     19.8
                                     8.58
                                     19.8
IN
Elkhart
                                     8.37
                                     23.5
                                     8.37
                                     23.5
IN
Floyd
                                     8.08
                                     18.0
                                     8.08
                                     18.0
IN
Lake
                                     8.92
                                     22.2
                                     8.92
                                     22.2
IN
Marion
                                     9.61
                                     22.0
                                     9.61
                                     22.0
IN
St. Joseph
                                     8.72
                                     20.4
                                     8.72
                                     20.4
IN
Vanderburgh
                                     8.40
                                     17.5
                                     8.40
                                     17.5
IN
Vigo
                                     8.47
                                     19.2
                                     8.47
                                     19.2
KS
Wyandotte
                                     8.15
                                     19.9
                                     8.15
                                     19.9
KY
Jefferson
                                     8.85
                                     19.5
                                     8.85
                                     19.5
LA
Caddo
                                     9.44
                                     19.6
                                     9.44
                                     19.6
LA
East Baton Rouge
                                     8.69
                                     20.7
                                     8.69
                                     20.7
LA
Iberville
                                     8.06
                                     18.6
                                     8.06
                                     18.6
LA
St. Bernard
                                     8.11
                                     17.4
                                     8.11
                                     17.4
LA
West Baton Rouge
                                     8.67
                                     18.7
                                     8.67
                                     18.7
MD
Howard
                                     8.21
                                     18.6
                                     8.21
                                     18.6
MD
Baltimore (City)
                                     8.17
                                     21.5
                                     8.17
                                     21.5
MI
Kent
                                     8.49
                                     22.5
                                     8.49
                                     22.5
MI
Wayne
                                     10.06
                                     24.1
                                     10.06
                                     24.1
MS
Hinds
                                     8.08
                                     18.1
                                     8.08
                                     18.1
MO
Buchanan
                                     8.15
                                     17.1
                                     8.15
                                     17.1
MO
Jackson
                                     8.09
                                     18.1
                                     8.09
                                     18.1
MO
Jefferson
                                     8.51
                                     18.4
                                     8.51
                                     18.4
MO
Saint Louis
                                     8.82
                                     19.1
                                     8.82
                                     19.1
MO
St. Louis City
                                     8.36
                                     19.8
                                     8.36
                                     19.8
MT
Lewis and Clark
                                     8.57
                                     37.6
                                     8.03
                                     35.4
MT
Lincoln
                                     11.08
                                     33.2
                                     11.08
                                     33.2
MT
Missoula
                                     9.53
                                     29.6
                                     9.53
                                     29.6
MT
Ravalli
                                     8.75
                                     38.0
                                     8.11
                                     35.4
MT
Silver Bow
                                     8.64
                                     30.6
                                     8.64
                                     30.6
NE
Douglas
                                     8.08
                                     17.8
                                     8.08
                                     17.8
NE
Sarpy
                                     8.10
                                     17.5
                                     8.10
                                     17.5
NV
Clark
                                     9.24
                                     23.0
                                     9.24
                                     23.0
NJ
Camden
                                     9.21
                                     22.3
                                     9.21
                                     22.3
NJ
Union
                                     8.62
                                     21.3
                                     8.62
                                     21.3
NM
Dona Ana
                                     8.57
                                     27.6
                                     8.57
                                     27.6
NY
New York
                                     8.95
                                     22.1
                                     8.95
                                     22.1
NC
Davidson
                                     8.29
                                     18.1
                                     8.29
                                     18.1
NC
Mecklenburg
                                     8.15
                                     17.5
                                     8.15
                                     17.5
NC
Wake
                                     8.12
                                     16.7
                                     8.12
                                     16.7
OH
Butler
                                     9.82
                                     20.7
                                     9.82
                                     20.7
OH
Cuyahoga
                                     10.23
                                     21.8
                                     10.23
                                     21.8
OH
Franklin
                                     8.17
                                     17.9
                                     8.17
                                     17.9
OH
Hamilton
                                     8.91
                                     20.1
                                     8.91
                                     20.1
OH
Jefferson
                                     9.26
                                     22.3
                                     9.26
                                     22.3
OH
Lucas
                                     8.70
                                     19.4
                                     8.70
                                     19.4
OH
Mahoning
                                     8.20
                                     19.0
                                     8.20
                                     19.0
OH
Stark
                                     8.92
                                     19.9
                                     8.92
                                     19.9
OH
Summit
                                     8.72
                                     19.9
                                     8.72
                                     19.9
OK
Tulsa
                                     8.13
                                     19.5
                                     8.13
                                     19.5
OR
Crook
                                     8.29
                                     35.5
                                     8.27
                                     35.4
OR
Harney
                                     8.61
                                     30.8
                                     8.61
                                     30.8
OR
Jackson
                                     9.18
                                     17.3
                                     9.18
                                     17.3
OR
Klamath
                                     8.64
                                     31.2
                                     8.64
                                     31.2
OR
Lake
                                     7.89
                                     37.3
                                     7.42
                                     35.4
OR
Lane
                                     8.12
                                     29.0
                                     8.12
                                     29.0
PA
Allegheny
                                     11.19
                                     34.7
                                     11.19
                                     34.7
PA
Armstrong
                                     9.28
                                     19.3
                                     9.28
                                     19.3
PA
Beaver
                                     8.44
                                     19.1
                                     8.44
                                     19.1
PA
Berks
                                     8.18
                                     23.9
                                     8.18
                                     23.9
PA
Cambria
                                     9.08
                                     22.8
                                     9.08
                                     22.8
PA
Chester
                                     8.97
                                     22.1
                                     8.97
                                     22.1
PA
Dauphin
                                     8.37
                                     24.5
                                     8.37
                                     24.5
PA
Delaware
                                     9.96
                                     23.6
                                     9.96
                                     23.6
PA
Lackawanna
                                     8.07
                                     18.6
                                     8.07
                                     18.6
PA
Lancaster
                                     10.14
                                     26.8
                                     10.14
                                     26.8
PA
Lebanon
                                     9.10
                                     27.1
                                     9.10
                                     27.1
PA
Lehigh
                                     8.17
                                     21.0
                                     8.17
                                     21.0
PA
Mercer
                                     8.42
                                     19.6
                                     8.42
                                     19.6
PA
Philadelphia
                                     9.75
                                     22.7
                                     9.75
                                     22.7
PA
Washington
                                     8.37
                                     19.0
                                     8.37
                                     19.0
PA
York
                                     8.56
                                     21.4
                                     8.56
                                     21.4
RI
Providence
                                     8.27
                                     17.9
                                     8.27
                                     17.9
SC
Greenville
                                     8.16
                                     18.6
                                     8.16
                                     18.6
TN
Davidson
                                     8.17
                                     16.9
                                     8.17
                                     16.9
TN
Knox
                                     8.60
                                     19.3
                                     8.60
                                     19.3
TX
Cameron
                                     9.75
                                     24.5
                                     9.75
                                     24.5
TX
Dallas
                                     8.08
                                     17.1
                                     8.08
                                     17.1
TX
El Paso
                                     9.08
                                     23.8
                                     9.08
                                     23.8
TX
Harris
                                     10.37
                                     22.0
                                     10.37
                                     22.0
TX
Hidalgo
                                     10.29
                                     25.8
                                     10.29
                                     25.8
TX
Nueces
                                     9.03
                                     23.9
                                     9.03
                                     23.9
TX
Travis
                                     9.07
                                     18.8
                                     9.07
                                     18.8
UT
Box Elder
                                     6.51
                                     31.7
                                     6.51
                                     31.7
UT
Cache
                                     7.07
                                     32.7
                                     7.07
                                     32.7
UT
Davis
                                     7.27
                                     31.1
                                     7.27
                                     31.1
UT
Salt Lake
                                     8.20
                                     37.4
                                     7.71
                                     35.4
UT
Utah
                                     7.63
                                     31.5
                                     7.63
                                     31.5
UT
Weber
                                     7.99
                                     30.8
                                     7.99
                                     30.8
WA
King
                                     8.31
                                     26.5
                                     8.31
                                     26.5
WA
Kittitas
                                     7.37
                                     38.0
                                     6.73
                                     35.4
WA
Okanogan
                                       -
                                     31.8
                                       -
                                     31.8
WA
Snohomish
                                     7.07
                                     31.3
                                     7.07
                                     31.3
WA
Spokane
                                     8.18
                                     27.2
                                     8.18
                                     27.2
WA
Yakima
                                     8.18
                                     38.8
                                     7.34
                                     35.4
WV
Berkeley
                                     8.21
                                     22.1
                                     8.21
                                     22.1
WV
Brooke
                                     8.41
                                     19.8
                                     8.41
                                     19.8
WV
Marshall
                                     8.46
                                     19.7
                                     8.46
                                     19.7
a The Hidden Valley site in Pinal County (04-021-3015) was not compared with the annual NAAQS in this analysis because it is a replacement site for the Cowtown Road site that was not comparable to the annual NAAQS (PCAQCD, 2020).

 2A.3	Developing Air Quality Ratios and Estimating Emission Reductions
As in the RIAs for the 2012 PM2.5 NAAQS review (USEPA, 2012a, USEPA, 2012b), air quality ratios are used here to estimate the emission reductions beyond the 2032 modeling case that are needed to meet the existing and alternative standards. Air quality ratios are developed from sensitivity modeling with CMAQ and relate a change in PM2.5 DV to a change in emissions. Air quality ratios have units of g m[-3] per kton of emissions. The remainder of this section describes the development of air quality ratios and their application to estimating emission reductions for meeting the existing and alternative standards.  
    2A.3.1	Developing Air Quality Ratios for Primary PM2.5 Emissions
To develop air quality ratios that relate the change in DV in a county to the change in primary PM2.5 emissions in that county, CMAQ sensitivity modeling was performed with reductions in primary PM2.5 emissions in selected counties. The modeling was conducted using CMAQ version 5.2.1 for a 2028 modeling case similar to that of recent regional haze modeling (USEPA, 2019b) due to the availability of the 2028 (but not 2032) modeling platform at the time of the work. 
To develop air quality ratios for primary PM2.5 emissions, a 2028 CMAQ sensitivity simulation was conducted with 50% reductions in primary PM2.5 emissions from anthropogenic sources in counties with annual 2028 DVs greater than 8 g m[-3] (Figure 2A-28). The change in annual and 24-hour PM2.5 DVs in these counties was then divided by the change in emissions in the respective counties to determine the air quality ratio at individual monitors as follows:
      AQratioPM2.5,i,j=∆DVi∆EmissCtyjx1000			(2A-1)
where DV is the change in design value (g m[-3]) between the 2028 base case and the simulation with 50% reduction in primary PM2.5 emissions at a monitor i in a county j, EmissCty is the change in primary PM2.5 emissions (tons) in county j between the 2028 base case and the simulation with 50% reduction in primary PM2.5 emissions, and the factor of 1000 converts units from (g m[-3] per ton) to (g m[-3] per kton).  
                                       
                                       
Figure 2A-28	Counties with 50% Reduction in Anthropogenic Primary PM2.5 Emissions in 2028 Sensitivity Modeling

Representative air quality ratios for regions of the US were developed from the ratios at individual monitors as in the 2012 PM - 2.5 NAAQS review (USEPA, 2012b). Regional ratios were calculated as the 75[th] percentile of air quality ratios at monitors within five regions: Northeast, Southeast, Northern California, Southern California, and West (Figure 2A-29). The Northeast region was defined by combining the Upper Midwest, Ohio Valley, and Northeast US climate regions (Figure 2A-2); the Southeast region was defined by combining the Southeast and South climate regions (Figure 2A-2); and California was separated into Southern and Northern regions as done previously (USEPA, 2012b). The air quality ratios for primary PM2.5 emissions used in estimating the emission reductions needed to just meet standards are listed in Table 2A-9.
                                       
                                       
Figure 2A-29	Regional Groupings for Calculating Air Quality Ratios

Table 2A-9	Annual and 24-Hour Air Quality Ratios for Primary PM2.5 Emissions
Region
                           Annual Air Quality Ratio
                             (g m[-3] per kton)
                           24-hour Air Quality Ratio
                             (g m[-3] per kton)
Northeast
                                     1.37
                                     4.33
Southeast
                                     1.22
                                     3.51
West
                                     2.14
                                     8.70
Northern California
                                     3.15
                                     9.97
Southern California
                                     1.18
                                     2.56

The air quality ratios in Table 2A-9 relate the change in DV in a given county to a change in emissions in that county. The ratios are developed for local spatial scales because concentrations are most responsive to changes in local emissions. However, emission controls may not always be identified in the local county, and emission reductions in neighboring counties may sometimes be appropriate, such as in the eastern US where counties are relatively small, and terrain is relatively flat. To apply emission reductions in the neighboring counties in the eastern US, the responsiveness of annual PM2.5 DVs to emission reductions within a county was compared with the responsiveness for neighboring counties as estimated from the 2028 sensitivity modeling. 
First, county groups of most relevance were identified from the 2028 sensitivity modeling. These groups were selected as eastern counties where emission reductions were applied and whose neighbors were not also neighbors of another county where emission reductions were applied. This set of county groups was then subset from the full list of counties and filtered to ensure that at least one monitor was included in the neighbor counties for the county group. The resulting county groups are shown in Figure 2A-30. The average relative responsiveness of annual DVs in the east for emission reductions in a core county to reductions in a neighboring county was then calculated as follows:
      ImpactRatio=mean(∆DVcore)mean(∆DVneighbor)=4			(2A-2)
where the numerator is the average impact on annual PM2.5 DVs in the core counties with 50% reduction in anthropogenic primary PM2.5 emissions, and the denominator is the average impact on annual PM2.5 DVs in neighboring counties. The resulting impact ratio suggests that primary PM2.5 emission reductions in neighboring counties would be 4x less effective as in the core county.
                                       
                                       
Figure 2A-30	Counties Used in Estimating the Relative Impact of Emissions in Core and Neighboring Counties

    2A.3.2	Developing Air Quality Ratios for NOx in Southern California
As described above, PM2.5 DVs exceeded the existing standards at monitors in the South Coast Air Basin in the 2032 modeling case. PM2.5 DVs were adjusted to meet the existing standards in these counties in creating the 12/35 analytical baseline. Since concentrations of ammonium nitrate are elevated in South Coast, NOx emission reductions were applied in these counties in addition to primary PM2.5 emission reductions to meet 12/35. For this purpose, air quality ratios were developed that relate a change in PM2.5 DVs to a change in NOx emissions at monitors in Southern California.  
The air quality ratios were developed from a CMAQ sensitivity simulation with 50% reductions in anthropogenic NOx emissions relative to the 2028 modeling case. The 50% emission reductions were applied in counties with annual 2028 DVs greater than 8 g m[-3] and their neighboring counties (Figure 2A-31). The change in annual and 24-hour DVs in these counties was then divided by the change in emissions in the respective county groups to determine the air quality ratio at individual monitors as follows:
            AQratioPM2.5,i,j=∆DVi∆EmissCtyGroupjx1000			(2A-3)
where DV is the change in design value (g m[-3]) between the 2028 base case and the simulation with 50% reduction in NOx emissions at monitor i, EmissCtyGroup is the change in NOx emissions (ton) in the county group associated with county j between the 2028 base case and the simulation with 50% reduction in NOx emissions, and the factor of 1000 converts units from (g m[-3] per ton) to (g m[-3] per kton).
 
                                       
                                       
Figure 2A-31	Counties with 50% Reduction in Anthropogenic NOx Emissions in 2028 Sensitivity Modeling
      

The county groups for determining the emission change to associate with the DV change in Equation 2A-3 are defined in Table 2A-10. These county groups were identified by first selecting the county of focus plus the neighboring counties to reflect the regional nature of ammonium nitrate formation from NOx emissions. These county groups were then refined to account for the influence of terrain, which limits air mixing between different air basins, on meteorology and air pollution. For instance, although Kern County neighbors Los Angeles County, Kern is part of the SJV air basin while Los Angeles is part of the South Coast Air Basin. Kern is therefore not included in the county group associated with Los Angeles County, because Kern is separated from Los Angeles County by mountain ranges.  
Table 2A-10	County Groups for Calculating Air Quality Ratios for NOx Emission Changes in Southern California
FIPS
County
County Group
06025
Imperial
Imperial; San Diego
06037
Los Angeles
Los Angeles; Orange; San Bernardino; Ventura
06065
Riverside
Riverside; Orange; San Bernardino
06071
San Bernardino
San Bernardino; Los Angeles; Orange; Riverside
06073
San Diego
San Diego; Imperial; Orange
06111
Ventura
Ventura; Los Angeles; Santa Barbara

To develop representative air quality ratios (USEPA, 2012b) for Southern California, the 75[th] percentile of the air quality ratios for individual monitors in the six counties in Table 2A-10 was calculated. The resulting air quality ratio for the annual standard is 0.004 g m[-3] per kton and for the 24-hour standard ratio is 0.038 g m[-3] per kton. These ratios were applied to adjust 2032 PM2.5 DVs according to 75% reductions in anthropogenic NOx emissions for counties in South Coast Air Basin (i.e., LA, San Bernardino, Riverside, and Orange). The 75% reduction in emissions corresponded to 78,700 tons. The 2032 DVs and the NOx-adjusted DVs are shown in Table 2A-11 for the highest annual and 24-hour DV monitors in the county. Note that these emission reductions were applied in meeting the existing standards (12/35) and are therefore not part of the incremental cost and benefits of meeting alternative standards relative to the existing standards.
Table 2A-11	2032 PM2.5 DVs and NOx-adjusted PM2.5 DVs for the Highest Annual and 24-Hour DV Monitors in South Coast Counties
Site ID
County
                                   AQ Ratio
                                    Annual
                              (g m-3 per kton)
                                   AQ Ratio
                                    24-hour
                              (g m-3 per kton)
                                    2032 DV
                                    Annual
                                 (g m[-3])
                                    2032 DV
                                    24-hour
                                 (g m[-3])
                                  NOx-Adj DV
                                    Annual
                                 (g m[-3])
                                  NOx-Adj DV
                                    24-hour
                                 (g m[-3])
060371302
Los Angeles
                                     0.004
                                     0.038
                                     12.38
                                     34.9
                                     12.06
                                     31.9
060374008
Los Angeles
                                     0.004
                                     0.038
                                     12.73
                                     31.0
                                     12.41
                                     28.0
060592022
Orange
                                     0.004
                                     0.038
                                     7.79
                                     14.6
                                     7.47
                                     11.6
060590007
Orange
                                     0.004
                                     0.038
                                       -
                                     31.5
                                       -
                                     28.5
060658005
Riverside
                                     0.004
                                     0.038
                                     14.10
                                     39.9
                                     13.78
                                     36.9
060710027
San Bernardino
                                     0.004
                                     0.038
                                     14.96
                                     35.0
                                     14.64
                                     32.0

    2A.3.3	Developing Air Quality Ratios for NOx in SJV, CA
As in the South Coast Air Basin, PM2.5 DVs exceed existing standards in SJV in the 2032 modeling case, and concentrations of ammonium nitrate are elevated in SJV. To develop PM2.5 DVs for SJV counties in the 12/35 analytical baseline, NOx emission reductions were applied in addition to primary PM2.5 emission reductions. To develop air quality ratios for NOx emission changes in SJV, information was used from Appendix K of the 2018 SJV PM2.5 Plan (SJVAPCD, 2018). The Plan was based on fine-scale CMAQ modeling and provides useful information for characterizing the responsiveness of PM2.5 DVs to NOx emissions.  
The California Air Resources Board (CARB) modeled PM2.5 concentrations in SJV corresponding to 30% reductions in NOx emissions relative to a 2024 base case. The change in annual and 24-hour PM2.5 DVs at monitors in SJV was reported for the sensitivity simulation. Using this information, along with PM2.5 DVs and emissions information from the 2032 CMAQ modeling developed here, air quality ratios were calculated at monitors in SJV from the following equation:
      AQratioi=%Chg. DVi%Chg.EmisionSJVCARBDViEmissionSJV2032		(2A-4)
The parenthesis labeled CARB indicates values from the SJV Plan, and the parenthesis labeled 2032 indicates values from the 2032 CMAQ modeling described above. %Chg.DVi indicates the percent change in the design value for a given monitor, i, from Table 49 and 50 of Appendix K of the SJV Plan (SJVAPCD, 2018). %Chg.DVi ranged from 2.3% to 7.5% for annual DVs and from 7.0% to 16.3% for 24-hour DVs. %Chg.EmissionSJV indicates the percent change in NOx emissions in SJV and equaled 30%. DVi corresponds to the design value at monitor i, and EmissionSJV corresponds to the anthropogenic NOx emissions in SJV (i.e., 53,500 ton) in the 2032 CMAQ modeling developed here. Equation 2A-4 normalizes the percent changes from CARB's 2024 modeling to the PM2.5 DVs and emissions from the 2032 case for application here.
Air quality ratios were calculated as above for all monitors in SJV, except for the Tranquility monitor. The Tranquility monitor is in the Western part of Fresno County, away from the urban exceedance monitors, and has a low PM2.5 concentration (e.g., 2024 annual DV for CARB modeling is 5.6 g m[-3]). To develop representative air quality ratios for counties in SJV, the 75[th] percentile of air quality ratios over monitors in the SJV counties was calculated. These ratios were applied to adjust 2032 PM2.5 DVs according to 75% reductions in anthropogenic NOx emissions for counties in SJV. The 75% reduction in emissions corresponded to 40,200 tons. The 2032 DVs and the NOx-adjusted DVs are shown in Table 2A-12 for the highest annual and 24-hour DV monitors in the county. Note that these emission reductions were applied in meeting the existing standards (12/35) and are therefore not part of the incremental cost and benefits of meeting alternative standards relative to the existing standards.
Table 2A-12	2032 PM2.5 DVs and NOx-adjusted PM2.5 DVs for the Highest Annual and 24-Hour DV Monitors in SJV Counties
Site ID
County
                                   AQ Ratio
                                    Annual
                              (g m-3 per kton)
                                   AQ Ratio
                                    24-hour
                              (g m-3 per kton)
                                    2032 DV
                                    Annual
                                 (g m[-3])
                                    2032 DV
                                    24-hour
                                 (g m[-3])
                                  NOx-Adj DV
                                    Annual
                                 (g m[-3])
                                  NOx-Adj DV
                                    24-hour
                                 (g m[-3])
060190011
Fresno
                                     0.033
                                     0.337
                                     13.25
                                     50.8
                                     11.94
                                     37.3
060195025
Fresno
                                     0.033
                                     0.337
                                     13.34
                                     48.3
                                     12.03
                                     34.8
060290010
Kern
                                     0.041
                                     0.418
                                     14.40
                                     57.2
                                     12.74
                                     40.4
060290016
Kern
                                     0.041
                                     0.418
                                     16.20
                                     56.3
                                     14.54
                                     39.5
060311004
Kings
                                     0.072
                                     0.467
                                     15.27
                                     48.2
                                     12.37
                                     29.5
060392010
Madera
                                     0.038
                                     0.216
                                     12.13
                                     39.8
                                     10.60
                                     31.1
060470003
Merced
                                     0.027
                                     0.178
                                     11.88
                                     36.3
                                     10.79
                                     29.1
060771002
San Joaquin
                                     0.048
                                     0.164
                                     12.01
                                     35.7
                                     10.08
                                     29.1
060990006
Stanislaus
                                     0.034
                                     0.222
                                     12.43
                                     38.7
                                     11.08
                                     29.8
061072002
Tulare
                                     0.047
                                     0.472
                                     14.66
                                     46.5
                                     12.76
                                     27.6

    2A.3.4	Applying Air Quality Ratios to Estimate Emission Reductions
The emissions reductions needed to just meet standards were estimated using the primary PM2.5 air quality ratios in combination with the required incremental change in concentration. The emission reductions required to meet the DV target for a standard were calculated as follows:
      ∆Emissionstd=DVModel,std-DVTarget,stdAQratiostdx1000			(2A-5)
where Emissionstd is the emission reduction required to meet an annual or 24-hour standard; DVTarget,std is the level of the annual or 24-hour standard to be met; DVModel,std is the modeled PM2.5 DV for the annual or 24-hour standard at the county highest monitor; AQratiostd is the air quality ratio for that standard; and the factor of 1000 converts units from kton to ton.  
For example, the highest 2032 annual PM2.5 DV in Kern County is 14.54 g m[-3] at site 06-029-0016 after applying the 75% NOx emission reduction to the 2032 DVs. The annual air quality ratio for primary PM2.5 emissions in Northern California is 3.15 g m[-3] per kton. Therefore, to meet an annual standard of 12 g m[-3], a total of 794 tons of primary PM2.5 emissions would be needed (i.e., (14.54-12.04)/3.15 x 1000). The highest 2032 24-hour PM2.5 DV in Kern County is 40.4 g m[-3] at site 06-029-0010 after applying the 75% NOx emission reduction to the 2032 DVs. The 24-hour air quality ratio for primary PM2.5 emissions in Northern California is 9.97 g m[-3] per kton. Therefore, to meet a 24-hour standard of 35 g m[-3], a total of 502 tons of primary PM2.5 emissions would be needed (i.e., (40.4-35.4)/9.97 x 1000). To determine the emission reductions needed to meet an annual and 24-hour standard combination, the maximum needed emissions across standards is calculated as follows:
      ∆Emissionstd.combo=max∆EmissionAnnual,∆Emission24hr		(2A-6)
For the Kern County example, a total 794 tons of primary PM2.5 emission reductions are needed to meet the 12/35 standard combination (i.e., max(794,502)).  
The PM2.5 DVs associated with meeting a standard combination at the highest monitor in a county are calculated using the required emission reductions as follows:
      DVAnnual,std.combo=DVAnnual,initial-∆Emissionstd.comboxAQratioAnnual	(2A-8)
      DVDaily,std.combo=DVAnnual,initial-∆Emissionstd.comboxAQratioDaily	(2A-9)
In the Kern County example, the adjusted annual DV for the 12/35 case is 12.04 g m[-3] (14.54-794*3.15/1000) and the adjusted 24-hour DV is 32.5 g m[-3] (40.4-794*9.97/1000).
       2A.3.4.1 Emission Reductions Needed to Meet 12/35
In the 2032 projections, PM2.5 DVs exceeded the existing standards for some counties in the west (Figure 2A-26). To create the PM2.5 DVs for 12/35 analytical baseline, the reductions in primary PM2.5 emissions needed to just meet 12/35 at the highest DV monitor by county were calculated using the air quality ratios in Table 2A-9. PM2.5 DVs were then adjusted according to those emission reductions. In Table 2A-13, the primary PM2.5 emission reductions needed to meet 12/35 is shown by county for counties with annual DVs greater than 8 g m[-3] or 24-hour DVs greater than 30 g m[-3] (note that required emission reductions are zero for counties with DVs below 12/35). Table 2A-13 also includes the corresponding air quality ratios, the 2032 PM2.5 DVs (or NOx-adjusted DVs for South Coast and SJV counties), and the PM2.5 DVs that define the 12/35 analytical baseline.
Table 2A-13	Summary of Primary PM2.5 Emissions Reductions by County Needed to Meet the Existing Standards (12/35) for Counties with 2032a Annual DVs greater than 8 g m-3 or 24-Hour DVs Greater than 30 g m-3
State
County
                                  Emission
                                 2032 to 12/35
                                     (ton)
                                   AQ Ratio
                                    Annual
                              (g m-3 per kton)
                                   AQ Ratio
                                    24-hour
                              (g m-3 per kton)
                                  2032[a] DV
                                    Annual
                                 (g m[-3])
                                  2032[a] DV
                                    24-hour
                                 (g m[-3])
                                   12/35 DV
                                    Annual
                                 (g m[-3])
                                   12/35 DV
                                    24-hour
                                 (g m[-3])
AL
Jefferson
                                       0
                                     1.22
                                     3.51
                                     9.86
                                     20.1
                                     9.86
                                     20.1
AL
Talladega
                                       0
                                     1.22
                                     3.51
                                     8.20
                                     16.3
                                     8.20
                                     16.3
AZ
Maricopa
                                       0
                                     2.14
                                     8.70
                                     9.47
                                     26.7
                                     9.47
                                     26.7
AZ
Pinal
                                       0
                                     2.14
                                     8.70
                                     8.16
                                     34.2
                                     8.16
                                     34.2
AZ
Santa Cruz
                                       0
                                     2.14
                                     8.70
                                     8.99
                                     26.5
                                     8.99
                                     26.5
AR
Pulaski
                                       0
                                     1.22
                                     3.51
                                     8.99
                                     19.3
                                     8.99
                                     19.3
AR
Union
                                       0
                                     1.22
                                     3.51
                                     8.12
                                     17.0
                                     8.12
                                     17.0
CA
Alameda
                                       0
                                     3.15
                                     9.97
                                     10.14
                                     25.4
                                     10.14
                                     25.4
CA
Butte
                                       0
                                     3.15
                                     9.97
                                     8.28
                                     27.2
                                     8.28
                                     27.2
CA
Contra Costa
                                       0
                                     3.15
                                     9.97
                                     9.16
                                     25.1
                                     9.16
                                     25.1
CA
Fresno
                                      189
                                     3.15
                                     9.97
                                     12.03
                                     37.3
                                     11.43
                                     35.4
CA
Imperial
                                      349
                                     1.18
                                     2.56
                                     12.45
                                     32.4
                                     12.04
                                     31.5
CA
Kern
                                      791
                                     3.15
                                     9.97
                                     14.54
                                     40.4
                                     12.04
                                     32.5
CA
Kings
                                      104
                                     3.15
                                     9.97
                                     12.37
                                     29.5
                                     12.04
                                     28.4
CA
Los Angeles
                                      313
                                     1.18
                                     2.56
                                     12.41
                                     31.9
                                     12.04
                                     31.1
CA
Madera
                                       0
                                     3.15
                                     9.97
                                     10.60
                                     31.1
                                     10.60
                                     31.1
CA
Marin
                                       0
                                     3.15
                                     9.97
                                     8.18
                                     23.4
                                     8.18
                                     23.4
CA
Merced
                                       0
                                     3.15
                                     9.97
                                     10.79
                                     29.1
                                     10.79
                                     29.1
CA
Napa
                                       0
                                     3.15
                                     9.97
                                     10.09
                                     25.7
                                     10.09
                                     25.7
CA
Orange
                                       0
                                     1.18
                                     2.56
                                     7.47
                                     28.5
                                     7.47
                                     28.5
CA
Plumas
                                     1,244
                                     3.15
                                     9.97
                                     14.52
                                     47.8
                                     10.60
                                     35.4
CA
Riverside
                                     1,478
                                     1.18
                                     2.56
                                     13.78
                                     36.9
                                     12.04
                                     33.1
CA
Sacramento
                                       0
                                     3.15
                                     9.97
                                     9.29
                                     31.0
                                     9.29
                                     31.0
CA
San Bernardino
                                     2,209
                                     1.18
                                     2.56
                                     14.64
                                     32.0
                                     12.04
                                     26.3
CA
San Diego
                                       0
                                     1.18
                                     2.56
                                     9.16
                                     22.3
                                     9.16
                                     22.3
CA
San Joaquin
                                       0
                                     3.15
                                     9.97
                                     10.08
                                     29.1
                                     10.08
                                     29.1
CA
San Luis Obispo
                                       0
                                     3.15
                                     9.97
                                     9.63
                                     25.1
                                     9.63
                                     25.1
CA
Santa Clara
                                       0
                                     3.15
                                     9.97
                                     9.56
                                     26.0
                                     9.56
                                     26.0
CA
Siskiyou
                                       0
                                     3.15
                                     9.97
                                     7.77
                                     34.8
                                     7.77
                                     34.8
CA
Solano
                                       0
                                     3.15
                                     9.97
                                     9.04
                                     24.7
                                     9.04
                                     24.7
CA
Stanislaus
                                       0
                                     3.15
                                     9.97
                                     11.08
                                     29.8
                                     11.08
                                     29.8
CA
Sutter
                                       0
                                     3.15
                                     9.97
                                     8.82
                                     27.6
                                     8.82
                                     27.6
CA
Tulare
                                      230
                                     3.15
                                     9.97
                                     12.76
                                     27.6
                                     12.04
                                     25.3
CA
Ventura
                                       0
                                     1.18
                                     2.56
                                     9.23
                                     33.5
                                     9.23
                                     33.5
CO
Denver
                                       0
                                     2.14
                                     8.70
                                     9.04
                                     24.1
                                     9.04
                                     24.1
CO
Weld
                                       0
                                     2.14
                                     8.70
                                     8.14
                                     24.9
                                     8.14
                                     24.9
DE
New Castle
                                       0
                                     1.37
                                     4.33
                                     8.14
                                     21.4
                                     8.14
                                     21.4
DC
District of Columbia
                                       0
                                     1.22
                                     3.51
                                     8.21
                                     19.8
                                     8.21
                                     19.8
GA
Bibb
                                       0
                                     1.22
                                     3.51
                                     8.80
                                     18.3
                                     8.80
                                     18.3
GA
Clayton
                                       0
                                     1.22
                                     3.51
                                     8.57
                                     17.2
                                     8.57
                                     17.2
GA
Cobb
                                       0
                                     1.22
                                     3.51
                                     8.09
                                     16.6
                                     8.09
                                     16.6
GA
DeKalb
                                       0
                                     1.22
                                     3.51
                                     8.08
                                     18.2
                                     8.08
                                     18.2
GA
Dougherty
                                       0
                                     1.22
                                     3.51
                                     8.38
                                     21.3
                                     8.38
                                     21.3
GA
Floyd
                                       0
                                     1.22
                                     3.51
                                     8.72
                                     17.3
                                     8.72
                                     17.3
GA
Fulton
                                       0
                                     1.22
                                     3.51
                                     9.46
                                     20.4
                                     9.46
                                     20.4
GA
Gwinnett
                                       0
                                     1.22
                                     3.51
                                     8.06
                                     18.7
                                     8.06
                                     18.7
GA
Muscogee
                                       0
                                     1.22
                                     3.51
                                     8.68
                                     27.3
                                     8.68
                                     27.3
GA
Richmond
                                       0
                                     1.22
                                     3.51
                                     8.54
                                     21.0
                                     8.54
                                     21.0
GA
Wilkinson
                                       0
                                     1.22
                                     3.51
                                     8.97
                                     19.2
                                     8.97
                                     19.2
ID
Benewah
                                       0
                                     2.14
                                     8.70
                                     9.61
                                     35.2
                                     9.61
                                     35.2
ID
Canyon
                                       0
                                     2.14
                                     8.70
                                     8.86
                                     31.4
                                     8.86
                                     31.4
ID
Lemhi
                                      460
                                     2.14
                                     8.70
                                     11.03
                                     39.4
                                     10.05
                                     35.4
ID
Shoshone
                                      138
                                     2.14
                                     8.70
                                     11.04
                                     36.6
                                     10.75
                                     35.4
IL
Cook
                                       0
                                     1.37
                                     4.33
                                     9.43
                                     20.7
                                     9.43
                                     20.7
IL
Madison
                                       0
                                     1.37
                                     4.33
                                     9.03
                                     19.0
                                     9.03
                                     19.0
IL
Saint Clair
                                       0
                                     1.37
                                     4.33
                                     8.99
                                     17.6
                                     8.99
                                     17.6
IN
Allen
                                       0
                                     1.37
                                     4.33
                                     8.10
                                     19.6
                                     8.10
                                     19.6
IN
Clark
                                       0
                                     1.37
                                     4.33
                                     8.58
                                     19.8
                                     8.58
                                     19.8
IN
Elkhart
                                       0
                                     1.37
                                     4.33
                                     8.37
                                     23.5
                                     8.37
                                     23.5
IN
Floyd
                                       0
                                     1.37
                                     4.33
                                     8.08
                                     18.0
                                     8.08
                                     18.0
IN
Lake
                                       0
                                     1.37
                                     4.33
                                     8.92
                                     22.2
                                     8.92
                                     22.2
IN
Marion
                                       0
                                     1.37
                                     4.33
                                     9.61
                                     22.0
                                     9.61
                                     22.0
IN
St. Joseph
                                       0
                                     1.37
                                     4.33
                                     8.72
                                     20.4
                                     8.72
                                     20.4
IN
Vanderburgh
                                       0
                                     1.37
                                     4.33
                                     8.40
                                     17.5
                                     8.40
                                     17.5
IN
Vigo
                                       0
                                     1.37
                                     4.33
                                     8.47
                                     19.2
                                     8.47
                                     19.2
KS
Wyandotte
                                       0
                                     1.22
                                     3.51
                                     8.15
                                     19.9
                                     8.15
                                     19.9
KY
Jefferson
                                       0
                                     1.37
                                     4.33
                                     8.85
                                     19.5
                                     8.85
                                     19.5
LA
Caddo
                                       0
                                     1.22
                                     3.51
                                     9.44
                                     19.6
                                     9.44
                                     19.6
LA
East Baton Rouge
                                       0
                                     1.22
                                     3.51
                                     8.69
                                     20.7
                                     8.69
                                     20.7
LA
Iberville
                                       0
                                     1.22
                                     3.51
                                     8.06
                                     18.6
                                     8.06
                                     18.6
LA
St. Bernard
                                       0
                                     1.22
                                     3.51
                                     8.11
                                     17.4
                                     8.11
                                     17.4
LA
West Baton Rouge
                                       0
                                     1.22
                                     3.51
                                     8.67
                                     18.7
                                     8.67
                                     18.7
MD
Howard
                                       0
                                     1.37
                                     4.33
                                     8.21
                                     18.6
                                     8.21
                                     18.6
MD
Baltimore (City)
                                       0
                                     1.37
                                     4.33
                                     8.17
                                     21.5
                                     8.17
                                     21.5
MI
Kent
                                       0
                                     1.37
                                     4.33
                                     8.49
                                     22.5
                                     8.49
                                     22.5
MI
Wayne
                                       0
                                     1.37
                                     4.33
                                     10.06
                                     24.1
                                     10.06
                                     24.1
MS
Hinds
                                       0
                                     1.22
                                     3.51
                                     8.08
                                     18.1
                                     8.08
                                     18.1
MO
Buchanan
                                       0
                                     1.37
                                     4.33
                                     8.15
                                     17.1
                                     8.15
                                     17.1
MO
Jackson
                                       0
                                     1.37
                                     4.33
                                     8.09
                                     18.1
                                     8.09
                                     18.1
MO
Jefferson
                                       0
                                     1.37
                                     4.33
                                     8.51
                                     18.4
                                     8.51
                                     18.4
MO
Saint Louis
                                       0
                                     1.37
                                     4.33
                                     8.82
                                     19.1
                                     8.82
                                     19.1
MO
St. Louis City
                                       0
                                     1.37
                                     4.33
                                     8.36
                                     19.8
                                     8.36
                                     19.8
MT
Lewis and Clark
                                      253
                                     2.14
                                     8.70
                                     8.57
                                     37.6
                                     8.03
                                     35.4
MT
Lincoln
                                       0
                                     2.14
                                     8.70
                                     11.08
                                     33.2
                                     11.08
                                     33.2
MT
Missoula
                                       0
                                     2.14
                                     8.70
                                     9.53
                                     29.6
                                     9.53
                                     29.6
MT
Ravalli
                                      299
                                     2.14
                                     8.70
                                     8.75
                                     38.0
                                     8.11
                                     35.4
MT
Silver Bow
                                       0
                                     2.14
                                     8.70
                                     8.64
                                     30.6
                                     8.64
                                     30.6
NE
Douglas
                                       0
                                     2.14
                                     8.70
                                     8.08
                                     17.8
                                     8.08
                                     17.8
NE
Sarpy
                                       0
                                     2.14
                                     8.70
                                     8.10
                                     17.5
                                     8.10
                                     17.5
NV
Clark
                                       0
                                     2.14
                                     8.70
                                     9.24
                                     23.0
                                     9.24
                                     23.0
NJ
Camden
                                       0
                                     1.37
                                     4.33
                                     9.21
                                     22.3
                                     9.21
                                     22.3
NJ
Union
                                       0
                                     1.37
                                     4.33
                                     8.62
                                     21.3
                                     8.62
                                     21.3
NM
Dona Ana
                                       0
                                     2.14
                                     8.70
                                     8.57
                                     27.6
                                     8.57
                                     27.6
NY
New York
                                       0
                                     1.37
                                     4.33
                                     8.95
                                     22.1
                                     8.95
                                     22.1
NC
Davidson
                                       0
                                     1.22
                                     3.51
                                     8.29
                                     18.1
                                     8.29
                                     18.1
NC
Mecklenburg
                                       0
                                     1.22
                                     3.51
                                     8.15
                                     17.5
                                     8.15
                                     17.5
NC
Wake
                                       0
                                     1.22
                                     3.51
                                     8.12
                                     16.7
                                     8.12
                                     16.7
OH
Butler
                                       0
                                     1.37
                                     4.33
                                     9.82
                                     20.7
                                     9.82
                                     20.7
OH
Cuyahoga
                                       0
                                     1.37
                                     4.33
                                     10.23
                                     21.8
                                     10.23
                                     21.8
OH
Franklin
                                       0
                                     1.37
                                     4.33
                                     8.17
                                     17.9
                                     8.17
                                     17.9
OH
Hamilton
                                       0
                                     1.37
                                     4.33
                                     8.91
                                     20.1
                                     8.91
                                     20.1
OH
Jefferson
                                       0
                                     1.37
                                     4.33
                                     9.26
                                     22.3
                                     9.26
                                     22.3
OH
Lucas
                                       0
                                     1.37
                                     4.33
                                     8.70
                                     19.4
                                     8.70
                                     19.4
OH
Mahoning
                                       0
                                     1.37
                                     4.33
                                     8.20
                                     19.0
                                     8.20
                                     19.0
OH
Stark
                                       0
                                     1.37
                                     4.33
                                     8.92
                                     19.9
                                     8.92
                                     19.9
OH
Summit
                                       0
                                     1.37
                                     4.33
                                     8.72
                                     19.9
                                     8.72
                                     19.9
OK
Tulsa
                                       0
                                     1.22
                                     3.51
                                     8.13
                                     19.5
                                     8.13
                                     19.5
OR
Crook
                                      11
                                     2.14
                                     8.70
                                     8.29
                                     35.5
                                     8.27
                                     35.4
OR
Harney
                                       0
                                     2.14
                                     8.70
                                     8.61
                                     30.8
                                     8.61
                                     30.8
OR
Jackson
                                       0
                                     2.14
                                     8.70
                                     9.18
                                     17.3
                                     9.18
                                     17.3
OR
Klamath
                                       0
                                     2.14
                                     8.70
                                     8.64
                                     31.2
                                     8.64
                                     31.2
OR
Lake
                                      218
                                     2.14
                                     8.70
                                     7.89
                                     37.3
                                     7.42
                                     35.4
OR
Lane
                                       0
                                     2.14
                                     8.70
                                     8.12
                                     29.0
                                     8.12
                                     29.0
PA
Allegheny
                                       0
                                     1.37
                                     4.33
                                     11.19
                                     34.7
                                     11.19
                                     34.7
PA
Armstrong
                                       0
                                     1.37
                                     4.33
                                     9.28
                                     19.3
                                     9.28
                                     19.3
PA
Beaver
                                       0
                                     1.37
                                     4.33
                                     8.44
                                     19.1
                                     8.44
                                     19.1
PA
Berks
                                       0
                                     1.37
                                     4.33
                                     8.18
                                     23.9
                                     8.18
                                     23.9
PA
Cambria
                                       0
                                     1.37
                                     4.33
                                     9.08
                                     22.8
                                     9.08
                                     22.8
PA
Chester
                                       0
                                     1.37
                                     4.33
                                     8.97
                                     22.1
                                     8.97
                                     22.1
PA
Dauphin
                                       0
                                     1.37
                                     4.33
                                     8.37
                                     24.5
                                     8.37
                                     24.5
PA
Delaware
                                       0
                                     1.37
                                     4.33
                                     9.96
                                     23.6
                                     9.96
                                     23.6
PA
Lackawanna
                                       0
                                     1.37
                                     4.33
                                     8.07
                                     18.6
                                     8.07
                                     18.6
PA
Lancaster
                                       0
                                     1.37
                                     4.33
                                     10.14
                                     26.8
                                     10.14
                                     26.8
PA
Lebanon
                                       0
                                     1.37
                                     4.33
                                     9.10
                                     27.1
                                     9.10
                                     27.1
PA
Lehigh
                                       0
                                     1.37
                                     4.33
                                     8.17
                                     21.0
                                     8.17
                                     21.0
PA
Mercer
                                       0
                                     1.37
                                     4.33
                                     8.42
                                     19.6
                                     8.42
                                     19.6
PA
Philadelphia
                                       0
                                     1.37
                                     4.33
                                     9.75
                                     22.7
                                     9.75
                                     22.7
PA
Washington
                                       0
                                     1.37
                                     4.33
                                     8.37
                                     19.0
                                     8.37
                                     19.0
PA
York
                                       0
                                     1.37
                                     4.33
                                     8.56
                                     21.4
                                     8.56
                                     21.4
RI
Providence
                                       0
                                     1.37
                                     4.33
                                     8.27
                                     17.9
                                     8.27
                                     17.9
SC
Greenville
                                       0
                                     1.22
                                     3.51
                                     8.16
                                     18.6
                                     8.16
                                     18.6
TN
Davidson
                                       0
                                     1.37
                                     4.33
                                     8.17
                                     16.9
                                     8.17
                                     16.9
TN
Knox
                                       0
                                     1.37
                                     4.33
                                     8.60
                                     19.3
                                     8.60
                                     19.3
TX
Cameron
                                       0
                                     1.22
                                     3.51
                                     9.75
                                     24.5
                                     9.75
                                     24.5
TX
Dallas
                                       0
                                     1.22
                                     3.51
                                     8.08
                                     17.1
                                     8.08
                                     17.1
TX
El Paso
                                       0
                                     1.22
                                     3.51
                                     9.08
                                     23.8
                                     9.08
                                     23.8
TX
Harris
                                       0
                                     1.22
                                     3.51
                                     10.37
                                     22.0
                                     10.37
                                     22.0
TX
Hidalgo
                                       0
                                     1.22
                                     3.51
                                     10.29
                                     25.8
                                     10.29
                                     25.8
TX
Nueces
                                       0
                                     1.22
                                     3.51
                                     9.03
                                     23.9
                                     9.03
                                     23.9
TX
Travis
                                       0
                                     1.22
                                     3.51
                                     9.07
                                     18.8
                                     9.07
                                     18.8
UT
Box Elder
                                       0
                                     2.14
                                     8.70
                                     6.51
                                     31.7
                                     6.51
                                     31.7
UT
Cache
                                       0
                                     2.14
                                     8.70
                                     7.07
                                     32.7
                                     7.07
                                     32.7
UT
Davis
                                       0
                                     2.14
                                     8.70
                                     7.27
                                     31.1
                                     7.27
                                     31.1
UT
Salt Lake
                                      230
                                     2.14
                                     8.70
                                     8.20
                                     37.4
                                     7.71
                                     35.4
UT
Utah
                                       0
                                     2.14
                                     8.70
                                     7.63
                                     31.5
                                     7.63
                                     31.5
UT
Weber
                                       0
                                     2.14
                                     8.70
                                     7.99
                                     30.8
                                     7.99
                                     30.8
WA
King
                                       0
                                     2.14
                                     8.70
                                     8.31
                                     26.5
                                     8.31
                                     26.5
WA
Kittitas
                                      299
                                     2.14
                                     8.70
                                     7.37
                                     38.0
                                     6.73
                                     35.4
WA
Okanogan
                                       0
                                     2.14
                                     8.70
                                       -
                                     31.8
                                       -
                                     31.8
WA
Snohomish
                                       0
                                     2.14
                                     8.70
                                     7.07
                                     31.3
                                     7.07
                                     31.3
WA
Spokane
                                       0
                                     2.14
                                     8.70
                                     8.18
                                     27.2
                                     8.18
                                     27.2
WA
Yakima
                                      391
                                     2.14
                                     8.70
                                     8.18
                                     38.8
                                     7.34
                                     35.4
WV
Berkeley
                                       0
                                     1.37
                                     4.33
                                     8.21
                                     22.1
                                     8.21
                                     22.1
WV
Brooke
                                       0
                                     1.37
                                     4.33
                                     8.41
                                     19.8
                                     8.41
                                     19.8
WV
Marshall
                                       0
                                     1.37
                                     4.33
                                     8.46
                                     19.7
                                     8.46
                                     19.7
[a] For South Coast and SJV counties, these are DVs that result from applying 75% NOx emission reduction to the 2032 DVs.

       2A.3.4.2 Emission Reductions Needed to Meet 10/35, 9/35, 8/35, and 10/30
The primary PM2.5 emission reductions needed to meet the alternative standard levels of 10/35, 10/30, 9/35, and 8/35 relative to the 12/35 analytical baseline were calculated to inform identification of emission controls. These emission amounts were calculated using Equations 2A-5 and 2A-6 and the air quality ratios in the Table 2A-9 and are shown in Table 2A-14. The total emission reductions needed in the eastern and western US is also shown in Figure 2A-32 for the standard combinations.

                                       
Figure 2A-32	Total Primary PM2.5 Emission Reductions Needed to Meet the Alternative Standard Levels of 10/35, 10/30, 9/35, and 8/35 Relative to the 12/35 Analytical Baseline in the East and West

Table 2A-14	Primary PM2.5 Emission Reductions Needed to Meet the Alternative Standard Levels of 10/35, 10/30, 9/35, and 8/35 Relative to the 12/35 Analytical Baseline
State
County
                                   Emission
                                     10/35
                                     (ton)
                                   Emission
                                     9/35
                                     (ton)
                                   Emission
                                     8/35
                                     (ton)
                                   Emission
                                     10/30
                                     (ton)
Alabama
Jefferson
                                       0
                                      670
                                     1,488
                                       0
Alabama
Talladega
                                       0
                                       0
                                      131
                                       0
Arizona
Maricopa
                                       0
                                      201
                                      669
                                       0
Arizona
Pinal
                                       0
                                       0
                                      56
                                      437
Arizona
Santa Cruz
                                       0
                                       0
                                      444
                                       0
Arkansas
Pulaski
                                       0
                                       0
                                      777
                                       0
Arkansas
Union
                                       0
                                       0
                                      65
                                       0
California
Alameda
                                      32
                                      349
                                      666
                                      32
California
Butte
                                       0
                                       0
                                      76
                                       0
California
Contra Costa
                                       0
                                      38
                                      355
                                       0
California
Fresno
                                      440
                                      757
                                     1,074
                                      502
California
Imperial
                                     1,701
                                     2,551
                                     3,402
                                     1,701
California
Kern
                                      634
                                      951
                                     1,268
                                      634
California
Kings
                                      634
                                      951
                                     1,268
                                      634
California
Los Angeles
                                     1,701
                                     2,551
                                     3,402
                                     1,701
California
Madera
                                      179
                                      496
                                      813
                                      179
California
Marin
                                       0
                                       0
                                      44
                                       0
California
Merced
                                      237
                                      554
                                      871
                                      237
California
Napa
                                      16
                                      333
                                      650
                                      16
California
Orange
                                       0
                                       0
                                       0
                                       0
California
Plumas
                                      176
                                      493
                                      810
                                      502
California
Riverside
                                     1,701
                                     2,551
                                     3,402
                                     1,701
California
Sacramento
                                       0
                                      79
                                      396
                                      60
California
San Bernardino
                                     1,701
                                     2,551
                                     3,402
                                     1,701
California
San Diego
                                       0
                                      102
                                      953
                                       0
California
San Joaquin
                                      12
                                      329
                                      646
                                      12
California
San Luis Obispo
                                       0
                                      187
                                      504
                                       0
California
Santa Clara
                                       0
                                      165
                                      482
                                       0
California
Siskiyou
                                       0
                                       0
                                       0
                                      441
California
Solano
                                       0
                                       0
                                      317
                                       0
California
Stanislaus
                                      331
                                      648
                                      965
                                      331
California
Sutter
                                       0
                                       0
                                      247
                                       0
California
Tulare
                                      634
                                      951
                                     1,268
                                      634
California
Ventura
                                       0
                                      162
                                     1,012
                                     1,213
Colorado
Denver
                                       0
                                       0
                                      468
                                       0
Colorado
Weld
                                       0
                                       0
                                      47
                                       0
Delaware
New Castle
                                       0
                                       0
                                      73
                                       0
District Of Columbia
District of Columbia
                                       0
                                       0
                                      139
                                       0
Georgia
Bibb
                                       0
                                       0
                                      621
                                       0
Georgia
Clayton
                                       0
                                       0
                                      433
                                       0
Georgia
Cobb
                                       0
                                       0
                                      41
                                       0
Georgia
DeKalb
                                       0
                                       0
                                      33
                                       0
Georgia
Dougherty
                                       0
                                       0
                                      278
                                       0
Georgia
Floyd
                                       0
                                       0
                                      556
                                       0
Georgia
Fulton
                                       0
                                      343
                                     1,161
                                       0
Georgia
Gwinnett
                                       0
                                       0
                                      16
                                       0
Georgia
Muscogee
                                       0
                                       0
                                      523
                                       0
Georgia
Richmond
                                       0
                                       0
                                      409
                                       0
Georgia
Wilkinson
                                       0
                                       0
                                      760
                                       0
Idaho
Benewah
                                       0
                                      267
                                      734
                                      552
Idaho
Canyon
                                       0
                                       0
                                      383
                                      115
Idaho
Lemhi
                                       3
                                      471
                                      939
                                      574
Idaho
Shoshone
                                      330
                                      797
                                     1,265
                                      574
Illinois
Cook
                                       0
                                      285
                                     1,017
                                       0
Illinois
Madison
                                       0
                                       0
                                      724
                                       0
Illinois
Saint Clair
                                       0
                                       0
                                      695
                                       0
Indiana
Allen
                                       0
                                       0
                                      44
                                       0
Indiana
Clark
                                       0
                                       0
                                      395
                                       0
Indiana
Elkhart
                                       0
                                       0
                                      241
                                       0
Indiana
Floyd
                                       0
                                       0
                                      29
                                       0
Indiana
Lake
                                       0
                                       0
                                      644
                                       0
Indiana
Marion
                                       0
                                      417
                                     1,149
                                       0
Indiana
St. Joseph
                                       0
                                       0
                                      498
                                       0
Indiana
Vanderburgh
                                       0
                                       0
                                      263
                                       0
Indiana
Vigo
                                       0
                                       0
                                      315
                                       0
Kansas
Wyandotte
                                       0
                                       0
                                      90
                                       0
Kentucky
Jefferson
                                       0
                                       0
                                      593
                                       0
Louisiana
Caddo
                                       0
                                      327
                                     1,145
                                       0
Louisiana
East Baton Rouge
                                       0
                                       0
                                      531
                                       0
Louisiana
Iberville
                                       0
                                       0
                                      16
                                       0
Louisiana
St. Bernard
                                       0
                                       0
                                      57
                                       0
Louisiana
West Baton Rouge
                                       0
                                       0
                                      515
                                       0
Maryland
Howard
                                       0
                                       0
                                      124
                                       0
Maryland
Baltimore (City)
                                       0
                                       0
                                      95
                                       0
Michigan
Kent
                                       0
                                       0
                                      329
                                       0
Michigan
Wayne
                                      15
                                      746
                                     1,478
                                      15
Mississippi
Hinds
                                       0
                                       0
                                      33
                                       0
Missouri
Buchanan
                                       0
                                       0
                                      80
                                       0
Missouri
Jackson
                                       0
                                       0
                                      37
                                       0
Missouri
Jefferson
                                       0
                                       0
                                      344
                                       0
Missouri
Saint Louis
                                       0
                                       0
                                      571
                                       0
Missouri
St. Louis City
                                       0
                                       0
                                      234
                                       0
Montana
Lewis and Clark
                                       0
                                       0
                                       0
                                      574
Montana
Lincoln
                                      486
                                      954
                                     1,422
                                      486
Montana
Missoula
                                       0
                                      229
                                      697
                                       0
Montana
Ravalli
                                       0
                                       0
                                      33
                                      574
Montana
Silver Bow
                                       0
                                       0
                                      281
                                      23
Nebraska
Douglas
                                       0
                                       0
                                      19
                                       0
Nebraska
Sarpy
                                       0
                                       0
                                      28
                                       0
Nevada
Clark
                                       0
                                      94
                                      561
                                       0
New Jersey
Camden
                                       0
                                      124
                                      856
                                       0
New Jersey
Union
                                       0
                                       0
                                      424
                                       0
New Mexico
Dona Ana
                                       0
                                       0
                                      248
                                       0
New York
New York
                                       0
                                       0
                                      666
                                       0
North Carolina
Davidson
                                       0
                                       0
                                      204
                                       0
North Carolina
Mecklenburg
                                       0
                                       0
                                      90
                                       0
North Carolina
Wake
                                       0
                                       0
                                      65
                                       0
Ohio
Butler
                                       0
                                      571
                                     1,303
                                       0
Ohio
Cuyahoga
                                      139
                                      871
                                     1,603
                                      139
Ohio
Franklin
                                       0
                                       0
                                      95
                                       0
Ohio
Hamilton
                                       0
                                       0
                                      637
                                       0
Ohio
Jefferson
                                       0
                                      161
                                      893
                                       0
Ohio
Lucas
                                       0
                                       0
                                      483
                                       0
Ohio
Mahoning
                                       0
                                       0
                                      117
                                       0
Ohio
Stark
                                       0
                                       0
                                      644
                                       0
Ohio
Summit
                                       0
                                       0
                                      498
                                       0
Oklahoma
Tulsa
                                       0
                                       0
                                      74
                                       0
Oregon
Crook
                                       0
                                       0
                                      105
                                      574
Oregon
Harney
                                       0
                                       0
                                      267
                                      46
Oregon
Jackson
                                       0
                                      65
                                      533
                                       0
Oregon
Klamath
                                       0
                                       0
                                      281
                                      92
Oregon
Lake
                                       0
                                       0
                                       0
                                      574
Oregon
Lane
                                       0
                                       0
                                      37
                                       0
Pennsylvania
Allegheny
                                      842
                                     1,573
                                     2,305
                                      994
Pennsylvania
Armstrong
                                       0
                                      176
                                      907
                                       0
Pennsylvania
Beaver
                                       0
                                       0
                                      293
                                       0
Pennsylvania
Berks
                                       0
                                       0
                                      102
                                       0
Pennsylvania
Cambria
                                       0
                                      29
                                      761
                                       0
Pennsylvania
Chester
                                       0
                                       0
                                      681
                                       0
Pennsylvania
Dauphin
                                       0
                                       0
                                      241
                                       0
Pennsylvania
Delaware
                                       0
                                      673
                                     1,405
                                       0
Pennsylvania
Lackawanna
                                       0
                                       0
                                      22
                                       0
Pennsylvania
Lancaster
                                      73
                                      805
                                     1,537
                                      73
Pennsylvania
Lebanon
                                       0
                                      44
                                      776
                                       0
Pennsylvania
Lehigh
                                       0
                                       0
                                      95
                                       0
Pennsylvania
Mercer
                                       0
                                       0
                                      278
                                       0
Pennsylvania
Philadelphia
                                       0
                                      520
                                     1,251
                                       0
Pennsylvania
Washington
                                       0
                                       0
                                      241
                                       0
Pennsylvania
York
                                       0
                                       0
                                      381
                                       0
Rhode Island
Providence
                                       0
                                       0
                                      168
                                       0
South Carolina
Greenville
                                       0
                                       0
                                      98
                                       0
Tennessee
Davidson
                                       0
                                       0
                                      95
                                       0
Tennessee
Knox
                                       0
                                       0
                                      410
                                       0
Texas
Cameron
                                       0
                                      581
                                     1,398
                                       0
Texas
Dallas
                                       0
                                       0
                                      33
                                       0
Texas
El Paso
                                       0
                                      33
                                      850
                                       0
Texas
Harris
                                      270
                                     1,087
                                     1,905
                                      270
Texas
Hidalgo
                                      204
                                     1,022
                                     1,840
                                      204
Texas
Nueces
                                       0
                                       0
                                      809
                                       0
Texas
Travis
                                       0
                                      25
                                      842
                                       0
Utah
Box Elder
                                       0
                                       0
                                       0
                                      149
Utah
Cache
                                       0
                                       0
                                       0
                                      264
Utah
Davis
                                       0
                                       0
                                       0
                                      80
Utah
Salt Lake
                                       0
                                       0
                                       0
                                      574
Utah
Utah
                                       0
                                       0
                                       0
                                      126
Utah
Weber
                                       0
                                       0
                                       0
                                      46
Washington
King
                                       0
                                       0
                                      126
                                       0
Washington
Kittitas
                                       0
                                       0
                                       0
                                      574
Washington
Okanogan
                                       0
                                       0
                                       0
                                      161
Washington
Snohomish
                                       0
                                       0
                                       0
                                      103
Washington
Spokane
                                       0
                                       0
                                      65
                                       0
Washington
Yakima
                                       0
                                       0
                                       0
                                      574
West Virginia
Berkeley
                                       0
                                       0
                                      124
                                       0
West Virginia
Brooke
                                       0
                                       0
                                      271
                                       0
West Virginia
Marshall
                                       0
                                       0
                                      307
                                       0

 2A.4	Calculating PM2.5 Concentration Fields for Standard Combinations
National PM2.5 concentration fields corresponding to meeting the existing and alternative standards were developed to inform health benefit calculations. First, a gridded PM2.5 concentration field for the 2032 CMAQ modeling case was developed using the enhanced Voronoi Neighbor Average (eVNA) method (Ding et al., 2016, Gold et al., 1997, USEPA, 2007). Next, the incremental difference in annual PM2.5 DVs between the 2032 case and cases of meeting standard combinations was calculated at monitors and interpolated to the spatial grid. The resulting field of incremental PM2.5 concentration was then subtracted from the 2032 eVNA field to create the gridded field for the standard combination. The steps in developing the PM2.5 concentration fields are described further below.
    2A.4.1	Creating the PM2.5 Concentration Field for 2032
The gridded field of annual average PM2.5 concentrations for 2032 was developed using the eVNA method that combines information from the model and monitors to predict PM2.5 concentrations. The eVNA approach was applied using SMAT-CE, version 1.8, and has been previously described in EPA's modeling guidance document (USEPA, 2018) and the user's guide for the predecessor software to SMAT-CE (Abt, 2014). The method is briefly described here, and more details are available in the primary references.
Quarterly average PM2.5 component concentrations measured during the 2015-2017 period were interpolated to the spatial grid using inverse distance-squared-weighting of monitored concentrations that were further weighted by the ratio of the 2016 CMAQ value in the prediction grid cell to CMAQ value in the monitor-containing grid cell. Weighting by the ratio of CMAQ values adjusts the interpolation of monitor data to account for spatial gradients in the CMAQ fields. This step results in an interpolated field of gradient-adjusted observed concentrations for each PM2.5 component and each quarter:
      eVNAs,q,2016=WeightxMonitorx,s,qModels,q,2016Models,q,2016			(2A-10)
where 𝑒𝑉𝑁𝐴𝑠,𝑞,2016 is the gradient-adjusted quarterly-average concentration of PM2.5 component species, s, during quarter, q, at the prediction grid cell; 𝑊𝑒𝑖𝑔ℎ𝑡𝑥 is the inverse-distance-squared weight for monitor, x, at the location of the prediction grid cell; 𝑀𝑜𝑛𝑖𝑡𝑜𝑟𝑥,𝑠,𝑞 is the average of the quarterly-average monitored concentrations for species, s, at monitor, x, during quarter, q, in 2015-2017; 𝑀𝑜𝑑𝑒𝑙𝑠,𝑞,2016 is the quarterly-average 2016 CMAQ concentration of species, s, during quarter, q, in the prediction grid cell; and 𝑀𝑜𝑑𝑒𝑙𝑥,𝑠,𝑞,2016 is the quarterly-average 2016 CMAQ concentration of species, s, during quarter, q, in the grid cell of monitor, x.
The 2016 eVNA fields for quarterly-average PM2.5 component concentrations are the starting point for developing the 2032 PM2.5 concentration field. To create eVNA fields for PM2.5 components in 2032, the 2016 eVNA component concentration in each grid cell is multiplied by the corresponding ratio of the quarterly-average CMAQ concentration predictions in 2032 and 2016:
      eVNAs,q,2032=eVNAs,q,2016Models,q,2032Models,q,2016				(2A-11)
The PM2.5 concentration fields for quarters in 2032 are calculated by summing the 2032 PM2.5 component concentration by quarter. The 2032 PM2.5 concentration field is then calculated by averaging the 2032 quarterly PM2.5 concentrations. The resulting 2032 PM2.5 concentration fields is shown in Figure 2A-33. 
                                       
                                       
Figure 2A-33	PM2.5 Concentration for 2032 based on eVNA Method

    2A.4.2	Creating Spatial Fields Corresponding to Meeting Standards
To create spatial fields corresponding to meeting standard levels, the 2032 concentration field was adjusted according to the change in PM2.5 concentrations associated with the difference in annual PM2.5 DVs between the 2032 case and the cases where standards are met. To implement this adjustment, the difference in annual PM2.5 DVs was calculated at the county highest monitor between the 2032 case and cases of meeting the 12/35, 10/30, 10/35, 9/35, and 8/35 standard combinations. For the county non-highest monitors, the difference in PM2.5 DVs was estimated by proportionally adjusting DVs according to the percent change in PM2.5 DV at the highest monitor.  
Due to the relatively large size and complex terrain of counties in the western US, the proportional adjustment of DVs within counties was limited in some cases. Proportional adjustment was not applied to seven sites that have 2032 annual PM2.5 DVs less than 7 g m[-3] and are located within counties that exceed 12/35 standard combination: i.e., 06-029-0011 (Kern, CA), 06-037-9033 (Los Angeles, CA), 06-065-5001 (Riverside, CA), 06-071-8001 (San Bernardino, CA), 30-049-0004 (Lewis and Clark, MT), 49-035-1001 (Salt Lake, UT), 49-035-3013 (Salt Lake, UT). The relatively low annual PM2.5 DVs for these sites compared with the highest-DV monitor suggests they are influenced by different air pollution processes than the highest-DV monitor. Additionally, the annual PM2.5 DV at the 06-065-2002 site in Riverside County was not adjusted due to its location outside of the portion of the county within the South Coast Air Basin that contains the highest-DV monitor.
After adjusting the annual PM2.5 DVs at county monitors and calculating the difference in annual DVs between the 2032 case and cases of meeting the standard combinations, the annual PM2.5 DV differences were interpolated to the spatial grid using inverse-distance-squared VNA interpolation. The interpolated field was then clipped to grid cells within 50 km of monitors whose design values changed in meeting the standard level (USEPA, 2012a). An example of a spatial field for the incremental change in PM2.5 concentration between the 2032 case and the case of meeting the existing standard combination, 12/35, is shown in Figure 2A-34.

                                       
                                       
Figure 2A-34	PM2.5 Concentration Improvement Associated with Meeting 12/35 Relative to the 2032 Case

National PM2.5 concentration fields were developed for each standard combination by subtracting the corresponding VNA field of incremental PM2.5 concentration from the 2032 eVNA concentration field. The resulting PM2.5 concentration fields were then compared with regional estimates of background PM2.5 concentrations based on a previous CMAQ modeling study with North American anthropogenic emissions set to zero (see Table 3-23 of USEPA, 2009). For a small number of grid cells (two for the 9/35 case and seven for the 8/35 case) in the full attainment scenario, adjusted concentrations were below the Southern California background level of 0.84 g m[-3] and were reset to that value. These grid cells are over the mountain ranges downwind of Los Angeles and Bakersfield where concentrations are much lower than in the South Coast Air Basin and SJV. In the partial attainment case, all concentrations were above the regional background levels and no adjustments were applied.   
 2A.5	Calculating DV Impacts for Further EGU Emission Reductions
Additional EGU emissions reductions are expected to occur between 2016 and 2030 beyond those included in the 2032 CMAQ simulation. These additional emission reductions are mainly due to planned EGU retirements that were not known at the time of development of the emission projections. In this section, we consider the potential influence of these emission reductions on PM - 2.5 DVs. First, the influence of further primary PM2.5 emission reductions from EGUs on DVs is estimated for counties with 2032 PM2.5 DVs that exceed the alternative standard levels. Next, the regional impact on annual PM2.5 DVs of the estimated total SO2 and NOx emission reductions from EGUs in the eastern US is estimated. Finally, the influence of these SO2 and NOx emission reductions on annual PM2.5 DVs in nearby county groups is estimated for two areas with the largest SO2 reductions expected near monitors with 2032 PM2.5 that exceed alternative standard levels. 
    2A.5.1	Estimating the Influence of Additional Primary PM2.5 EGU Reductions
For ten of the counties with 2032 DVs that exceed the alternative annual standard level of 8 g m[-3] or the 24-hour standard level of 30 g m[-3], additional reductions in primary PM2.5 emissions from EGUs beyond the 2032 modeling case are expected. These counties are shown in Table 2A-15 with the expected emission reductions and the estimated influence on the annual and 24-hour DV. For reference, the 2032 DVs, corresponding to projections based on the CMAQ simulation of the 2032 emissions case (Section 2.2), are also shown in the Table. The DV impacts were calculated by applying the air quality ratios for these counties (Table 2A-9) to the emission estimates. The largest influence of the further EGU emission reductions is in Hamilton, OH (0.85 g m[-3]), Jefferson, MO (0.31 g m[-3]), and Allegheny, PA (0.18 g m[-3]). The significance of these DV reductions in the context of meeting alternative standard levels is discussed in section 3.2.4.

Table 2A-15	Primary PM2.5 Emission Reductions from EGUs Expected beyond 2032 Modeling Case and Estimated Impact on DVs for Counties Exceeding Alternative Standards in the 2032 Case
State
County
                                PM2.5 Emissions
                                   Reduction
                                     (ton)
                                     2032
                                 Annual DV[a]
                                 (g m[-3])
                                     2032
                                 24-hour DV[a]
                                 (g m[-3])
                                     DV
                                    Annual
                                 (g m[-3])
                                     DV
                                    24-hour
                                 (g m[-3])
Arizona
Maricopa
                                      6.0
                                     9.47
                                     26.7
                                     0.01
                                      0.1
California
Los Angeles
                                      5.9
                                     12.73
                                     34.9
                                     0.01
                                      0.0
Colorado
Weld
                                      0.1
                                     8.14
                                     24.9
                                     0.00
                                      0.0
Missouri
Jefferson
                                     229.0
                                     8.51
                                     18.4
                                     0.31
                                      1.0
Nevada
Clark
                                     19.4
                                     9.24
                                     23.0
                                     0.04
                                      0.2
Ohio
Hamilton
                                     619.0
                                     8.91
                                     20.1
                                     0.85
                                      2.7
Pennsylvania
Allegheny
                                     133.8
                                     11.19
                                     34.7
                                     0.18
                                      0.6
Texas
Dallas
                                     11.7
                                     8.08
                                     17.1
                                     0.01
                                      0.0
Texas
El Paso
                                      4.5
                                     9.08
                                     23.8
                                     0.01
                                      0.0
Texas
Travis
                                      2.9
                                     9.07
                                     18.8
                                     0.00
                                      0.0
   [a] The 2032 DVs correspond to projections based on the CMAQ simulation of the 2032 emissions case (Section 2.2) without any additional DV adjustments.
   
    2A.5.2	Estimating the Regional Influence of Additional SO2 and NOx EGU Emission Reductions
For states in the eastern US, a combined total of 170,411 tons of SO2 and 52,718 tons of NOx emission reductions are expected to occur from EGUs beyond the 2032 modeling case. The emission tons are listed by state and county in Table 2A-16. Sensitivity model simulations with 50% SO2 and NOx emission reductions relative to the 2028 case described above were used to estimate the regional influence of these emission reductions on annual DVs in the eastern US. 
The counties with 50% reductions of SO2 and NOx emissions in the 2028 CMAQ sensitivity simulations are shown in Figure 2A-35. The eastern states considered in this analysis are shaded in red in the figure. The total change in emissions in these states in the 50% NOx emission reduction simulation was 1,566,554 tons, and the total emission reduction was 479,342 tons in the 50% SO2 emission reduction simulation. To estimate the regional influence of the additional EGU emission reductions, the change in DVs for the sensitivity simulations was calculated at monitors in the eastern states and scaled by the ratio of the EGU emission reductions to the sensitivity simulation emission reductions (i.e., 52,718 tons / 1,566,554 tons for NOx, and 170,411 tons / 479,342 tons for SO2). Across monitors in the eastern states, the median total PM2.5 DV change estimated this way is 0.06 g m[-3] (25[th]/75[th] percentile: 0.05 g m[-3]/0.08 g m[-3]). The full distribution of the estimated changes in annual PM2.5 DVs is shown in Figure 2A-36. Due to differences in the spatial distribution and magnitude of the emission changes in the sensitivity simulations and the EGU reductions, the PM2.5 DV impacts are rough approximations, and photochemical modeling of the EGU reductions would be needed to provide better estimates.
Table 2A-16	SO2 and NOx Emission Reductions from EGUs Expected Beyond 2032 Modeling Case by County
State
County
                                      SO2
                                     (ton)
                                      NOx
                                     (ton)
Connecticut
Hartford
                                      385
                                     1,101
Florida
Alachua
                                       0
                                       2
Florida
Hillsborough
                                     1,328
                                      414
Illinois
Christian
                                     1,942
                                     1,133
Illinois
Jasper
                                     4,770
                                     1,934
Illinois
Lake
                                     1,024
                                      933
Illinois
Massac
                                    18,793
                                     4,237
Illinois
Randolph
                                     4,206
                                     5,100
Illinois
Will
                                      826
                                      983
Indiana
LaPorte
                                     1,289
                                     1,441
Indiana
Spencer
                                      35
                                      19
Indiana
Warrick
                                      766
                                      442
Iowa
Des Moines
                                       0
                                       5
Iowa
Muscatine
                                     1,039
                                     1,308
Iowa
Winnebago
                                       0
                                       9
Louisiana
Ascension
                                       0
                                      147
Louisiana
Calcasieu
                                       0
                                      656
Louisiana
Pointe Coupee
                                     4,225
                                     1,149
Louisiana
Rapides
                                    14,360
                                     1,278
Maryland
Montgomery
                                       0
                                      14
Massachusetts
Middlesex
                                       0
                                      77
Michigan
Eaton
                                     3,018
                                      892
Michigan
Ottawa
                                     6,799
                                     3,343
Minnesota
Blue Earth
                                      102
                                      602
Minnesota
Cook
                                      877
                                      477
Minnesota
Goodhue
                                      100
                                      543
Missouri
Franklin
                                    35,424
                                       -
Missouri
Jasper
                                       0
                                      76
Missouri
Jefferson
                                    37,421
                                     3,286
New Jersey
Essex
                                       0
                                      11
New Jersey
Salem
                                       0
                                       8
New Mexico
Lea
                                       0
                                       3
New York
Queens
                                       0
                                       7
North Carolina
Cleveland
                                     1,140
                                     2,082
Ohio
Clermont
                                    17,532
                                     5,849
Ohio
Hamilton
                                     3,663
                                     6,127
Ohio
Lorain
                                     3,799
                                     1,437
Oklahoma
Osage
                                       0
                                      13
Pennsylvania
Allegheny
                                      628
                                     1,254
Pennsylvania
Bucks
                                       0
                                      39
Pennsylvania
Northampton
                                       0
                                      25
Pennsylvania
Somerset
                                       0
                                      16
South Dakota
Minnehaha
                                       0
                                       1
Tennessee
Stewart
                                      720
                                      527
Texas
Bexar
                                     3,726
                                      751
Texas
Dallas
                                       0
                                      59
Texas
El Paso
                                       0
                                      328
Texas
Orange
                                       0
                                     1,246
Texas
Pecos
                                       0
                                       4
Texas
Travis
                                       0
                                      15
Virginia
Dinwiddie
                                       0
                                      30
Wisconsin
Marathon
                                       0
                                      77
Wisconsin
Milwaukee
                                      473
                                     1,206

                                       
Figure 2A-35 	PM2.5 Counties with 50% Reductions of SO2 Emissions in the 2028 CMAQ Sensitivity Simulations (Green) and Eastern States Considered in the EGU Sensitivity Analysis (Red)  

                                       
                                       
Figure 2A-36	Distributions of the Estimated Changes in Annual PM2.5 DVs in the Eastern U.S. Associated with NOx and SO2 EGU Emission Reductions in the Eastern US Beyond the 2032 Modeling Case     

    2A.5.3	Estimating the Local Influence of Additional SO2 and NOx EGU Emission Reductions
In addition to estimating potential regional impacts of the additional SO2 and NOx emissions reductions from EGUs, we considered the relatively local impacts of the reductions on DVs in nearby counties for two cases with large SO2 reductions. In one case, the EGU emission reductions in Franklin and Jefferson, MO, and Randolph, IL were grouped to give a total of 77,100 tons of SO2 and 8,390 tons of NOx emissions. To estimate the impact of these emission reductions, SO2 and NOx air quality ratios for nearby counties were developed using the 2028 sensitivity modeling. The change in annual DV at sites within the relevant cluster of counties with emission reductions in the 2028 sensitivity modeling (Figure 2A-37) was calculated and divided by the change in emissions in that county group in the sensitivity modeling. This yielded an average annual air quality ratio for NOx of 0.002 g m[-3] and for SO2 of 0.006 g m[-3] for estimating the impact of SO2 and NOx emission reductions in the county group on the DVs in that group. Applying these ratios to the combined emission reductions in Franklin, Jefferson, and Randolph counties, yields an increment in the annual PM2.5 DV of about 0.5 g m[-3]. The additional EGU emission reductions may have a DV impact of approximately this amount at the sites listed in Table 2A-17, although a better estimate could be provided through explicit photochemical modeling of the sources. The significance of these DV reductions in the context of meeting alternative standard levels is discussed in section 3.2.4.

                                       
                                       
Figure 2A-37	County Group in 2028 Sensitivity Modeling Used in Estimating the Response of DVs to EGU Emission Changes in Franklin and Jefferson, MO, and Randolph, IL  

Table 2A-17	2032 PM2.5 DVs and Estimated Influence of Emission Reductions from EGUs in Franklin and Jefferson, MO, and Randolph, IL on DVs in Nearby Counties  
Site ID
State
County
                                     2032
                                 Annual DV[a]
                                 (g m[-3])
                                     DV
                                    Annual
                                 (g m[-3])
171191007
Illinois
Madison
                                     9.03
                                      0.5
171630010
Illinois
Saint Clair
                                     8.99
                                      0.5
290990019
Missouri
Jefferson
                                     8.51
                                      0.5
291893001
Missouri
Saint Louis
                                     8.82
                                      0.5
295100085
Missouri
St. Louis City
                                     8.36
                                      0.5
              [a] The 2032 DVs correspond to projections based on the CMAQ simulation of 
              the 2032 emissions case (Section 2.2) without any additional DV adjustments.
              
In a second case, emission reductions in Clermont and Hamilton, OH were grouped to give a total of 21,190 tons of SO2 and 11,980 tons of NOx. To estimate the impact of these reductions on DVs in nearby counties, the change in annual DV at sites within the relevant cluster of counties with emission reductions in the 2028 sensitivity modeling (Figure 2A-38) was calculated and divided by the change in emissions in that county group in the sensitivity modeling. This yielded an average annual air quality ratio for NOx of 0.003 g m[-3] and for SO2 of 0.014 g m[-3] for estimating the impact of SO2 and NOx emission reductions in the county group on the DVs in that group. Applying these ratios to the combined emission reductions in Clermont and Hamilton counties, yields an increment in the annual PM2.5 DV of about 0.3 g m[-3]. The additional EGU emission reductions may have a DV impact of approximately this amount at the sites listed in Table 2A-18, although a better estimate could be provided through explicit photochemical modeling of the sources.   
                                       
                                       
Figure 2A-38	County Group in 2028 Sensitivity Modeling Used in Estimating the Response of DVs to EGU Emission Changes in Clermont and Hamilton, OH 

Table 2A-18	2032 PM2.5 DVs and Estimated Influence of Emission Reductions from EGUs in Clermont and Hamilton, OH on DVs in Nearby Counties  
Site ID
State
County
                                     2032
                                 Annual DV[a]
                                 (g m[-3])
                                     DV
                                    Annual
                                 (g m[-3])
390170022
Ohio
Butler
                                     9.82
                                      0.3
390610014
Ohio
Hamilton
                                     8.91
                                      0.3
              [a] The 2032 DVs correspond to projections based on the CMAQ simulation of 
              the 2032 emissions case (Section 2.2) without any additional DV adjustments.

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Appel, KW, Bash, JO, Fahey, KM, Foley, KM, Gilliam, RC, Hogrefe, C, Hutzell, WT, Kang, D, Mathur, R, Murphy, BN, Napelenok, SL, Nolte, CG, Pleim, JE, Pouliot, GA, Pye, HOT, Ran, L, Roselle, SJ, Sarwar, G, Schwede, DB, Sidi, FI, Spero, TL and Wong, DC (2021). The Community Multiscale Air Quality (CMAQ) model versions 5.3 and 5.3.1: system updates and evaluation. Geosci. Model Dev. 14(5): 2867-2897.
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