Appendix N.1

CMAQ Modeling for Reasonable 

Progress and BART Controls 
CMAQ Modeling for Reasonable Progress and BART Controls

GA EPD conducted CMAQ modeling to determine the SO2 impact on visibility from each unit

subject to analysis. This modeling was performed by zeroing out the SO2 emissions from each

facility (all units) and calculating the impacts on visibility at each Class I area. The impacts

(Mm-1) were apportioned to each unit by calculating the ratio of individual SO2 emissions from

each unit to the total SO2 emissions from the facility. A summary of these results is shown in

Table 1. Next, the modeling results were normalized by the emissions reduced from each unit to

obtain the visibility improvement resulting from each ton of SO2 reduced (Mm-1/ton). These

results are summarized in Table 2. A visibility cost efficiency metric can be calculated in dollar

per inverse megameter ($/Mm-1) by dividing the cost per ton SO2 reduction ($/ton) by the

visibility benefit per ton SO2 reduction (Mm-1/ton). This visibility cost efficiency metric was

considered in addition to the standard cost efficiency expressed in $/ton.

Next, modeled visibility impacts (Mm-1) at Class I areas due to new SO2 emission limits from

controlled units (Appendix H) were calculated by multiplying the SO2 reductions (tons/year) by

the normalized SO2 modeled sensitivity (Mm-1/ton) for each unit. These results are summarized

in Table 3. Finally, impacts were summed to give the total impact at each Class I area. Total

impacts were used to adjust the projected 2018 visibility projections and set new 2018 visibility

goals at each Class I area. 
Table 1: Modeled visibility impacts (Mm-1) at Class I areas from SO2 emission reductions (tons/year) from specifi

Facility Name Unit 2018 SO2 COHU GRSM OKEF ROMA SGEORGIA PACIFIC CORPORATION, CEDAR SPRIN R402 1726.31 -0.0575 -0.0230 -0.0067 -0.0066 -GEORGIA PACIFIC CORPORATION, CEDAR SPRIN U500 2428.38 -0.0809 -0.0323 -0.0095 -0.0093 -GEORGIA PACIFIC CORPORATION, CEDAR SPRIN U501 2532.99 -0.0844 -0.0337 -0.0099 -0.0097 -GEORGIA POWER COMPANY, MITCHELL STEAM-EL SG03 4929.74 -0.0604 -0.0565 -0.3028 -0.0399 -GEORGIA-PACIFIC BRUNSWICK OPERATIONS F1 1842.37 -0.0127 -0.0132 -0.2810 -0.1466 -GEORGIA-PACIFIC BRUNSWICK OPERATIONS M24 193.01 -0.0013 -0.0014 -0.0294 -0.0154 -GEORGIA-PACIFIC CORP SAVANNAH RIVER MILL BO01 1844.25 -0.0034 -0.0013 -0.0061 -0.0205 -GEORGIA-PACIFIC CORP SAVANNAH RIVER MILL BO02 1415.47 -0.0026 -0.0010 -0.0047 -0.0157 -GEORGIA-PACIFIC CORP SAVANNAH RIVER MILL BO03 1282.05 -0.0024 -0.0009 -0.0043 -0.0143 -INLAND PAPERBOARD & PACKAGING, INC. -LIN F2 1147.7 -0.0590 -0.0384 -0.0163 -0.0182 -INLAND PAPERBOARD & PACKAGING, INC. -LIN F4 3696.15 -0.1899 -0.1237 -0.0526 -0.0588 -INTERNATIONAL PAPER - SAVANNAH MILL PB13 8578.26 -0.1412 -0.0595 -0.5252 -1.1213 -INTERSTATE PAPER LLC F1 187.68 -0.0028 -0.0010 -0.0158 -0.0261 -JESUP MILL, RAYONIER PERFORMANCE FIBERS PB03 1596.95 -0.0149 -0.0110 -0.1453 -0.1506 -JESUP MILL, RAYONIER PERFORMANCE FIBERS PB02 623.85 -0.0058 -0.0043 -0.0568 -0.0588 -JESUP MILL, RAYONIER PERFORMANCE FIBERS RF01 333.28 -0.0031 -0.0023 -0.0303 -0.0314 -JESUP MILL, RAYONIER PERFORMANCE FIBERS RF04 333.87 -0.0031 -0.0023 -0.0304 -0.0315 -PACKAGING CORPORATION OF AMERICA - VALDO 1017 653.35 -0.0053 -0.0063 -0.1279 -0.0299 -SAVANNAH ELECTRIC: KRAFT STEAM - ELECTRI SG01 690.72 -0.0110 -0.0040 -0.0381 -0.0754 -SAVANNAH ELECTRIC: KRAFT STEAM - ELECTRI SG02 703.68 -0.0112 -0.0041 -0.0389 -0.0768 -SAVANNAH ELECTRIC: KRAFT STEAM - ELECTRI SG03 4474.37 -0.0715 -0.0260 -0.2470 -0.4882 -SAVANNAH ELECTRIC: MCINTOSH STEAM - ELEC SG01 7015.13 -0.1805 -0.0659 -0.3771 -1.3139 -SAVANNAH SUGAR REFINERY U161 997.42 -0.0164 -0.0069 -0.0611 -0.1304 -SOUTHERN STATES PHOSPHATE & FERTILIZER C SA02 807.68 -0.0133 -0.0056 -0.0494 -0.1056 -
Table 2: Modeled visibility impacts (Mm-1/ton) at Class I areas from SO2 emission reductions (tons/year) from sp

Facility Name Unit 2018 SO2 COHU GRSM OKEF ROMA GEORGIA PACIFIC CORPORATION, CEDAR SPRIN R402 -3.33E-05 -1.33E-05 -3.90E-06 -3.82E-06 -1.97E-06 GEORGIA PACIFIC CORPORATION, CEDAR SPRIN U500 -3.33E-05 -1.33E-05 -3.90E-06 -3.82E-06 -1.97E-06 GEORGIA PACIFIC CORPORATION, CEDAR SPRIN U501 -3.33E-05 -1.33E-05 -3.90E-06 -3.82E-06 -1.97E-06 GEORGIA POWER COMPANY, MITCHELL STEAM-EL SG03 -1.23E-05 -1.15E-05 -6.14E-05 -8.10E-06 -3.05E-05 GEORGIA-PACIFIC BRUNSWICK OPERATIONS F1 -6.90E-06 -7.15E-06 -1.53E-04 -7.96E-05 -1.97E-05 GEORGIA-PACIFIC BRUNSWICK OPERATIONS M24 -6.90E-06 -7.15E-06 -1.53E-04 -7.96E-05 -1.97E-05 GEORGIA-PACIFIC CORP SAVANNAH RIVER MILL BO01 -1.85E-06 -6.89E-07 -3.32E-06 -1.11E-05 -1.07E-06 GEORGIA-PACIFIC CORP SAVANNAH RIVER MILL BO02 -1.85E-06 -6.89E-07 -3.32E-06 -1.11E-05 -1.07E-06 GEORGIA-PACIFIC CORP SAVANNAH RIVER MILL BO03 -1.85E-06 -6.89E-07 -3.32E-06 -1.11E-05 -1.07E-06 INLAND PAPERBOARD & PACKAGING, INC. -LIN F2 -5.14E-05 -3.35E-05 -1.42E-05 -1.59E-05 -1.16E-05 INLAND PAPERBOARD & PACKAGING, INC. -LIN F4 -5.14E-05 -3.35E-05 -1.42E-05 -1.59E-05 -1.16E-05 INTERNATIONAL PAPER - SAVANNAH MILL PB13 -1.65E-05 -6.93E-06 -6.12E-05 -1.31E-04 -1.49E-05 INTERSTATE PAPER LLC F1 -1.49E-05 -5.40E-06 -8.41E-05 -1.39E-04 -1.89E-05 JESUP MILL, RAYONIER PERFORMANCE FIBERS PB03 -9.31E-06 -6.90E-06 -9.10E-05 -9.43E-05 -1.47E-05 JESUP MILL, RAYONIER PERFORMANCE FIBERS PB02 -9.31E-06 -6.90E-06 -9.10E-05 -9.43E-05 -1.47E-05 JESUP MILL, RAYONIER PERFORMANCE FIBERS RF01 -9.31E-06 -6.90E-06 -9.10E-05 -9.43E-05 -1.47E-05 JESUP MILL, RAYONIER PERFORMANCE FIBERS RF04 -9.31E-06 -6.90E-06 -9.10E-05 -9.43E-05 -1.47E-05 PACKAGING CORPORATION OF AMERICA - VALDO 1017 -8.14E-06 -9.63E-06 -1.96E-04 -4.57E-05 -5.22E-05 SAVANNAH ELECTRIC: KRAFT STEAM - ELECTRI SG01 -1.60E-05 -5.81E-06 -5.52E-05 -1.09E-04 -1.28E-05 SAVANNAH ELECTRIC: KRAFT STEAM - ELECTRI SG02 -1.60E-05 -5.81E-06 -5.52E-05 -1.09E-04 -1.28E-05 SAVANNAH ELECTRIC: KRAFT STEAM - ELECTRI SG03 -1.60E-05 -5.81E-06 -5.52E-05 -1.09E-04 -1.28E-05 SAVANNAH ELECTRIC: MCINTOSH STEAM - ELEC SG01 -2.57E-05 -9.39E-06 -5.38E-05 -1.87E-04 -1.73E-05 SAVANNAH SUGAR REFINERY U161 -1.65E-05 -6.93E-06 -6.12E-05 -1.31E-04 -1.49E-05 SOUTHERN STATES PHOSPHATE & FERTILIZER C SA02 -1.65E-05 -6.93E-06 -6.12E-05 -1.31E-04 -1.49E-05 
Table 3: Modeled visibility impacts (Mm-1) at Class I areas from new SO2 emission limits (tons/year) from contro

Facility Name Unit SO2 Limit COHU GRSM OKEF ROMA SGEORGIA PACIFIC CORPORATION, CEDAR SPRIN U500 591 -0.0612 -0.0245 -0.0072 -0.0070 -0GEORGIA PACIFIC CORPORATION, CEDAR SPRIN U501 591 -0.0647 -0.0258 -0.0076 -0.0074 -0GEORGIA-PACIFIC BRUNSWICK OPERATIONS F1 568 -0.0088 -0.0091 -0.1944 -0.1014 -0INTERNATIONAL PAPER - SAVANNAH MILL PB13 6578 -0.0329 -0.0139 -0.1225 -0.2615 -0INTERSTATE PAPER LLC F1 2 -0.0028 -0.0010 -0.0156 -0.0258 -0JESUP MILL, RAYONIER PERFORMANCE FIBERS PB03 149 -0.0135 -0.0100 -0.1317 -0.1365 -0JESUP MILL, RAYONIER PERFORMANCE FIBERS PB02 318 -0.0028 -0.0021 -0.0278 -0.0288 -0JESUP MILL, RAYONIER PERFORMANCE FIBERS RF01 194 -0.0013 -0.0010 -0.0127 -0.0131 -0JESUP MILL, RAYONIER PERFORMANCE FIBERS RF04 307 -0.0003 -0.0002 -0.0024 -0.0025 -0PACKAGING CORPORATION OF AMERICA - VALDO 1017 600 -0.0004 -0.0005 -0.0104 -0.0024 -0SOUTHERN STATES PHOSPHATE & FERTILIZER C SA02 600 -0.0034 -0.0014 -0.0127 -0.0271 -0TOTAL IMPACT -0.1922 -0.0895 -0.5450 -0.6138 -0