WRAP REGIONAL HAZE MODELING 2028 Visibility Projections and

WRAP REGIONAL HAZE MODELING 2028 Visibility Projections and First Round of Potential Additional Controls (PAC 1) RTOWG Webinar July 15, 2020

INTRODUCTION MELA 1 • 2028 Visibility Projections o Two sets of 2028 visibility projections made so far using EPA default visibility projection approach and CAMx modeling results: § Rep. Base/2028 OTBa w/ Rep. Base fires § 2014 v 2/2028 OTBb w/ 2014 v 2 actual fires • Developed two alternative 2028 visibility projection approaches: MEVE 1 o EPAwo. F: Like EPA default using RRFs based on modeling results for days from 2014 IMPROVE MID only without using modeled contributions from fires that are eliminated using source apportionment o Mod. MID: Use modeled most U. S. anthropogenic emissions impaired days from 2014 IMPROVE sample days with contributions of fires eliminated using source apportionment GUMO 1

EPA Default Future Year Visibility Projection Method • EPA recommended visibility projection method using Rep. Base and 2028 OTBa CAMx modeling results that used 2014 base year meteorology but 2014 -2018 base year emissions: o Species-specific RRF based on ratio of 2028 OTBa to Rep. Base CAMx modeling results averaged across observed IMPROVE 2014 MID § RRF = ∑ CAMx 2014 MID 2028 / ∑ CAMx 2014 MIDRep. Base o Apply RRF to IMPROVE 2014 -2018 MIFD to obtained 2028 visibility projection § Visibility MID 20208 = IMPROVE MID 2014 -2018 x RRF o Issue: Modeled fire impacts on IMPROVE 2014 MID can make RRF stiff and unresponsive

Alternative 2028 Visibility Projection Approaches • Alternative 2028 projection methods to EPA • One reason alternative approaches don’t default approach (EPAwo. F and Mod. MID) do not make huge differences is biggest impact produce very different visibility projections. of fires is on Organic Matter Carbon (OMC) whose RRF is already very stiff • Largest differences with EPA default is for (close to 1. 0) even without fires. Mod. MID approach as it not only eliminates fire contributions in the RRFs but also using different • Example for Bext OMC below for days. Yellowstone and Rep. Base source apportionment across 2014 IMPROVE MID YELL Bext. OMC Extinction SOAB Wildfire

POTENTIAL ADDITIONAL CONTROLS • Some WRAP states provided a first round of Potential Additional Controls (PAC 1) in 2028 that are used to make 2028 PAC 1 visibility projections o Initial 2028 PAC 1 visibility projections were made using EPA default projection approach • Issues found in 2028 emission inventories with double counted O&G sources mainly in New Mexico so doing minimal analysis of PAC 1 results while fixing inventory • Expected state emissions reductions o Actual emission reductions were different for some states

ACTUAL PAC 1 TOTAL EMISSION REDUCTIONS BY STATE NOx AZ CO ID MT ND NM NV OR SD UT WA WY SO 2 1, 651 2, 092 314 0 675 1, 335 55 458 4, 118 18, 655 28, 937 7, 704 1, 006 885 2, 832 440 1 0 -1 0 0 0 -2, 272 3, 467 PM 25 Comment -61 -1 -65 1 0 6 126 1, 101 0 0 0 1, 406 Primarily EGUs + PM 2. 5 from fugitive dust O&G Non-Point Non-EGU Point O&G Point EGU Point O&G Non-Point and Point Mainly EGU, some Non-EGU Point EGU and Non-EGU AZ Fugitive Dust

EGU and Non-EGU Point Sources Percent Change in 2028 Visibility Changes (TPY) -0. 2% (lower deciview value, better projected visibility in 2028) -18, 000 -4, 000 +4, 000 -0. 7% +2, 000 -0. 2% -0. 5% -800 -600 -1, 000 -0. 2% -2, 000 -400 -0. 6% -0. 3% -0. 2% -0. 6% -0. 1% -0. 3% -2, 800 -700 -2, 000 -400 -1, 300 -4, 500 -50 -400 -200 -0. 3% -1. 4% -0. 5%

Oil and Gas and Fugitive Dust PM 2. 5 Changes (TPY) Percent Change in 2028 Visibility (lower deciview value, better projected visibility in 2028) -25, 000 -0. 6% -0. 3% -0. 8% -0. 3% -0. 6% -500 -3, 000 -700 -0. 2%

2028 OTBa vs PAC 1 MID Projections • Very small reductions in 2028 projected visibility due to PAC 1 controls o Max = -1. 4% (-0. 14 dv) @ SAGU, AZ § 2 nd High = -1. 1% (-0. 16 dv) @ SACR, NM o Mostly hundredths of dv o 73% of sites reductions of at least -0. 01 dv § Sites with no change away from emission reductions (e. g. , CA) Site State SAGU 1 AZ SACR 1 NM BADL 1 SD SAPE 1 NM MEVE 1 CO WHPE 1 NM WHRI 1 CO LOST 1 ND WHIT 1 NM PEFO 1 AZ MOZI 1 CO BAND 1 NM WEMI 1 CO MOHO 1 OR THRO 1 ND BRID 1 WY TONT 1 AZ HECA 1 OR GRSA 1 CO CHIR 1 AZ GICL 1 NM SYCA 2 AZ GRCA 2 AZ BALD 1 AZ IKBA 1 AZ BOAP 1 NM CANY 1 UT MELA 1 MT CRMO 1 ID WICA 1 SD ROMO 1 CO THSI 1 OR SIAN 1 AZ BRCA 1 UT STAR 1 OR YELL 2 WY JARB 1 NV CAPI 1 UT VOYA 2 MN GUMO 1 TX KALM 1 OR 2028 (dv) OTBa PAC 1 10. 13 9. 99 14. 71 14. 55 11. 84 11. 74 5. 91 5. 86 6. 19 6. 15 5. 50 4. 48 4. 44 16. 25 16. 14 9. 73 9. 67 7. 44 7. 39 4. 88 4. 85 8. 02 7. 97 6. 08 6. 05 8. 30 13. 95 13. 86 6. 33 6. 29 9. 64 9. 58 11. 52 11. 46 7. 54 7. 50 8. 73 8. 69 7. 18 7. 15 10. 99 10. 94 6. 37 6. 34 6. 67 6. 64 8. 61 8. 58 10. 04 10. 00 6. 15 6. 12 15. 44 15. 38 7. 51 7. 49 9. 86 7. 44 10. 78 10. 75 8. 50 8. 48 6. 02 6. 01 10. 20 10. 17 7. 05 7. 03 7. 77 7. 75 6. 67 6. 65 13. 37 13. 34 12. 27 12. 24 11. 51 Difference (%) (dv) -1. 4% -0. 14 -1. 1% -0. 16 -0. 9% -0. 10 -0. 8% -0. 05 -0. 8% -0. 04 -0. 7% -0. 03 -0. 7% -0. 11 -0. 6% -0. 06 -0. 6% -0. 05 -0. 6% -0. 03 -0. 6% -0. 05 -0. 6% -0. 04 -0. 6% -0. 05 -0. 6% -0. 08 -0. 6% -0. 04 -0. 6% -0. 05 -0. 5% -0. 06 -0. 5% -0. 04 -0. 5% -0. 03 -0. 5% -0. 05 -0. 4% -0. 03 -0. 4% -0. 04 -0. 4% -0. 02 -0. 3% -0. 05 -0. 3% -0. 02 -0. 3% -0. 03 -0. 3% -0. 02 -0. 2% -0. 03 -0. 2% -0. 02

Conclusions 2028 PAC 1 • As expected, very small changes in projected 2028 MID dv o Mostly hundredths of dv changes o Largest changes in or near states with emissions reductions (e. g. , NM, AZ, ND) o Smallest changes away from such states (e. g. , CA) • Round 2 of Potential Additional Controls (PAC 2) o Need state emission changes to be tested by Sept. 10, 2020 • Caveats: o 2028 OTB emissions include double counted O&G sources § In both 2028 OTBa and 2028 PAC 1 § Does not affect the reductions in 2028 MID due to PAC 1 controls § Probably minimal affect on 2028 MID projections