1. Use of Hybrid Plume/Grid Modeling and the St. Louis Super Site Data to Model PM 2.5 Concentrations in the St. Louis Area Ralph Morris, Bonyoung Koo, Jeremiah, Johnson and Greg Yarwood ENVIRON International Corporation Jay Turner and Jennifer Garlock Washington University

2. St. Louis 2003-2005 Annual PM 2.5 Design Values – Two Sites Violate the NAAQS of 15.0 μg/m 3 : Granite City (17.0 μg/m 3 ) and East St. Louis (15.5 μg/m 3 )

3. St. Louis Regional PM 2.5 Modeling 36/12 km Modeling Grid MM5 Meteorological Model SMOKE Emissions Model CMAQ & CAMx photochemical grid models Model Performance Evaluation –Initially with Routine STN and FRM Networks –More Detailed with St. Louis Super Site PM Source Apportionment Technology (PSAT) 2009 PM 2.5 Design Value Projections

4. St. Louis Regional 36/12 km grid CMAQ V4.5 SOAmods Boundary Conditions (BCs) for 36 km Domain from VISTAS Continental U.S. 36 km CMAQ Simulations (Whose BCs in turn were from a 2002 GEOS- CHEM global chemistry model simulation)

5. = STN Site

6. CMAQ 2002 Annual PM 2.5 Constituents PM 2.5 [  g/m 3 ] Overestimation of “Other” PM 2.5 – traced to overstated fugitive dust sources SO4, NO3, NH4 and EC performance good. OA performance poor

7. AltonArnold BlairCAP StL SS SO4: Good Agreement Both CMAQ (FB = -12% to -21%) and CAMx (FB = +3% to +6%). Some localized spikes not captured (note: spike on day 185 @ StL SS is due to July 4 fireworks not in inventory)

8. AltonArnold BlairCAP StL SS OMC: Mostly Under-Estimated CMAQ (FB = -68% to -89%) and CAMx (FB = -55% to -88%) both systematic under-prediction

9. MDNR STL 2002 Design Value (Left) and 2009 CAMx Base4 12k projected DVF (Middle Left) and 2009 CMAQ Base4 12k projected DVF (Middle Right) and 2009 CMAQ BaseG2 12k projected DVF (Right) 0 2 4 6 8 10 12 14 16 18 20 Granite City Alton Wood River Tilden City East St. Louis Swansea Arnold West Alton Sunset Hills Clayton Ferguson S. Broadway Blair St. Margaretta 2nd & Mound STL ug/m3 PBW NH4 Crustal EC OC NO3 SO4 2009 Projected PM 2.5 Design Values

10. PM Source Apportionment Technology (PSAT) -- Granite City 2009 PM 2.5 : Source Categories by Species  Overstated fugitive dust emissions

11. Granite City 2009 PSAT: Species by Source Categories

12. Granite City 2009 PSAT: Source Regions by Categories

13. PMF Source Apportionment Modeling using StL-SS data. Combined PMF Factor Analysis for Industrial Source#1 Factor with Wind Direction at StL-SS Shows Large Contribution from Granite City Steel Works Direction

14. Wind Analysis of Local vs. Regional PM 2.5 Concentrations at Granite City Monitor (B) Identifies GCW Steel Mill & Coke Ovens as Local Contributor

15. St. Louis PM 2.5 : Regional and Local Problem CMAQ/CAMx 36/12 km Modeling Insufficient to Capture Local Contributions – Need Enhanced Approach: 1.Use hybrid Plume/Grid modeling approach with AERMOD/ISC Local and CMAQ/CAMx: Problems with mixing modeling results as CMAQ/CAMx designed to be accurate, AERMOD/ISC designed to be conservative. 2.Use Grid Model with Plume-in-Grid (PiG) for local-scale sources: 12 km grid still very course for sources not treated with PiG. 3.Use CMAQ/CAMx with finer grids: For example 36/12/4/1.33 km, however even 1.33 km may be insufficient to model local source impacts at Granite City 4.Use combined CMAQ/CAMx finer grids with PiG for local sources: Combines best features of (2) and (3) without problems of (1).  Decision to proceed with high resolution grid with PiG model (Option 4).

16. Preliminary 36/12/4/1 km CAMx modeling   Even 1 km grid insufficient to capture separation between Granite City sources and monitoring sites (shown are CAMx annual average 1 km model estimates)

17. St. Louis Hybrid Multi-Scale PM Modeling Approach Global-Scale: GEOS-CHEM provided BCs to Inter RPO USA Domain Continental-Scale: VISTAS 36 km CMAQ simulations Regional-Scale: 36/12 km CMAQ/CAMx modeling of StL regional-scale domain Urban-Scale: CAMx 12/4/1.33 km two-way nesting Local-Scale: 1.33 km and finer? plus Plume-in- Grid with CAMx two-way 12/4/1.33/0.444 km grids

18. CAMx V4.5 Plume-in-Grid Module Secondary Order Closure (SOC) horizontal and vertical diffusion* Full ozone and PM chemistry using Incremental Chemistry approach* Subgrid-scale sampling receptors Releases to grid model when size permits * Adapted from SCICHEM model

19. St. Louis PM 2.5 SIP Modeling – Next Steps Testing of Urban- and Local-Scale 12/4/1.33 km CAMx modeling –Feasibility of finer (444 m) grids –Use of PiG subgrid-scale puff model Updated 2002 and 2012 emissions and modeling for Regional-scale CMAQ/CAMx 36/12 km and Local-Scale 12/4/1 km CAMx modeling Comprehensive model performance evaluation using St. Louis Super Site, STN and FRM data 2012 PM 2.5 Design Value projections Control strategy development and modeling Final documentation for PM 2.5 SIP due April 2008