1. V:\corporate\marketing\overview.ppt CRGAQS: Latest CAMx 2018 Results Presentation to the Gorge Study Technical Team ENVIRON International Corporation Alpine Geophysics, LLC May 23, 2007

2. V:\corporate\marketing\overview.ppt Today’s Presentation Review 2004 extinction against IMROVE Review modeled organic carbon components Show revised nephelometer comparisons –Account for high humidity in November episode Latest 2018 CAMx simulations –Review results for August episode Compare 2004, 2018 and 2018 What-if’s –Review results for November episode Compare 2004, 2018 and 2018 What-if’s –Trend lines Next Steps

3. V:\corporate\marketing\overview.ppt 2004 Extinction vs IMPROVE

4. V:\corporate\marketing\overview.ppt 2004 Extinction vs IMPROVE

5. V:\corporate\marketing\overview.ppt CAMx Organics Primary organic aerosol (POA) –Sources: any combustion –Emitted as a stable aerosol No evaporation/re-condensation Secondary organic aerosol (SOA) –VOCs oxidize to condensable gases –SOA forms as f(T, RH, aerosol mass) –Condensation/evaporation possible

6. V:\corporate\marketing\overview.ppt CAMx Organics CAMx treats 5 kinds of SOA –SOA1-3 from anthropogenic VOC sources Tracks formation from aromatics and parafins Combustion and fugitive sources –SOA4-5 from biogenic VOC Terpenes generate two SOA products Less apt to evaporate Updates coming for both CAMx and CMAQ –Sesqueterpenes and isoprene

7. V:\corporate\marketing\overview.ppt 2004 vs. 2018 Results (August)

8. V:\corporate\marketing\overview.ppt 2004 vs. 2018 Results (August)

9. V:\corporate\marketing\overview.ppt 2004 vs. 2018 Results (November)

10. V:\corporate\marketing\overview.ppt 2004 vs. 2018 Results (November)

11. V:\corporate\marketing\overview.ppt November Nephelometer

12. V:\corporate\marketing\overview.ppt November Nephelometer

13. V:\corporate\marketing\overview.ppt What-if Scenarios Case 01 – zero Boardman emissions Case 02 – zero NH3 emissions for PSAT region 5 (east of Gorge) Case 03 – zero on-road mobile source emissions for PSAT region 2 (Portland and Vancouver) Case 04 – zero major point source emissions for PSAT region 2 Case 05 – zero major point source emissions for PSAT region 1 (in-Gorge)

14. V:\corporate\marketing\overview.ppt PSAT Regions

15. V:\corporate\marketing\overview.ppt 2004 vs. 2018 Results (August)

16. V:\corporate\marketing\overview.ppt 2004 vs. 2018 Results (August)

17. V:\corporate\marketing\overview.ppt August Trend Lines -0.33 Mm-1 per year -0.99 Mm-1 per year -0.03 per year -0.10 per year-6.2 Mm-1 -10% -13.9 Mm-1 -27% -0.44 -1.35

18. V:\corporate\marketing\overview.ppt 2004 vs. 2018 Results (November)

19. V:\corporate\marketing\overview.ppt 2004 vs. 2018 Results (November)

20. V:\corporate\marketing\overview.ppt November Trend Lines -2.42 Mm-1 per year -3.67 Mm-1 per year -0.03 per year -0.05 per year -33.9 Mm-1 -9% -51.4 Mm-1 -15% -0.42 -0.72

21. V:\corporate\marketing\overview.ppt Next Steps Apply modeled changes to observed levels Finish PSAT (2004/2018, August/ November) Complete report