Statewide Protocol: - Overview of Tools for Microscale Modeling and Integration -

1. Statewide Protocol: - Overview of Tools for Microscale Modeling and Integration - Beth Schwehr Planning and Technical Support Division California Air Resources Board August 27, 2003

2. Regional Grid Modeling & Microscale Modeling • Regional Grid Modeling Strengths: • Photochemistry • Long-range transport; urban background • Microscale Modeling Strengths: • Near-source peaks • Busy roadways; ground-level sources • Neighborhood resolution • Need to integrate, avoid double counting

3. Modeling Framework CHAPIS Emissions and Meteorology Microscale Modeling Regional Modeling Integrated Results HARP Risk Assessment Mapping and Visualization

4. Modeling Framework: Tools Emissions and Meteorology Microscale Modeling Regional Modeling Automation Tools Integrated Results Integration Tools Risk Assessment Risk Assessment & Mapping Tools Mapping and Visualization

5. Goal: Develop a Practical Approach Based on Lessons from Neighborhood Assessment Program • Benefits of Neighborhood Assessment Program (NAP) Pilot Studies: • Two major studies: Barrio Logan, Wilmington • Detailed local emission inventories -- help identify sources that matter for nearby impacts • Community air monitoring • Tracer studies • Compare modeled and observed concentrations • Develop/test new modeling protocols for regional and local-scale modeling -- sensitivity analysis

6. Continuously Improve Approach Research & NAP Studies Improved Refined Approach Statewide Risk Modeling/Mapping Existing Tools Iterative Process Other Studies

7. Microscale Modeling Challenges • Emissions • Stack Characterization and Activity Data for key sources • “Complex Point Sources” (include On-site Mobile Diesel) • Link-Based Roadway Emissions • Meteorology • Availability and Representativeness • Fill Gaps? Regional Met Model Run Times (~months) • Modeling • Microscale Model Choice • Mobile Source Input Data: Spatial and Temporal Resolution • Automate Microscale Modeling – sparse “mini-grids”

8. Microscale Modeling for Statewide Application • Domain • Sparse “mini-grid” concept • Meteorology • Emissions and Modeling • Point Sources • Off-road Diesel (“Complex point sources”) • On-road, Link-Based Sources • Integration, risk, and display tools

9. Statewide Domain • Single Domain is Computationally Prohibitive • Sparse “mini-grid” concept • Snap to universal statewide grid • Staged Approach • Begin in Southern California domain

10. Other Studies • U.S. EPA Region 6 “RAIMI” approach • Regional Air Impacts Modeling Initiative (RAIMI) • Practical approaches for large domains • Overlapping source-centered modeling • On a universal grid • U.S. EPA “Example Application of Modeling Air Toxics in an Urban Area” • Modeled facilities and roadway links with ISC • Continue to track advanced model options

11. Concept: Sparse “Mini-Grids” and Integration with Regional Grid Local Grids Around Major Roads, Key Facilities (where local impacts may be important) = 50/million = 100/million Emissions and Meteorology Microscale Modeling Regional Modeling Integrated Results Risk Assessment B Mapping and Visualization A Microscale (sample): = 1/million

12. Microscale Modeling for Statewide Application • Domain • Sparse “mini-grid” concept • Meteorology • Emissions and Modeling • Point Sources • Off-road Diesel (“Complex point sources”) • On-road, Link-Based Sources • Integration, risk, and display tools

13. Meteorology Data for Microscale Modeling • Weather station data into ISC format • ~120 sites • Gaps in coverage • Regional met models may be a future supplement • Associate a met set with each source or grid tile for processing • Examine topography, wind roses

14. (20 km tiles with 1km grid shown)

15. Microscale Modeling for Statewide Application • Domain • Sparse “mini-grid” concept • Meteorology • Emissions and Modeling • Point Sources • Off-road Diesel (“Complex point sources”) • On-road, Link-Based Sources • Integration, risk, and display tools

16. Point Sources for Microscale Modeling • Identify Key Source Types -- Factors: • Lessons from NAP Studies • Prioritization “scoring” of reported toxic emissions • Data of reasonable quality available • Phased Approach • One priority: ground-level releases of potent toxics • Coordination with HRAs & categories recently updated • Data Gaps • Stack Parameters – U.S. EPA defaults if unavailable • Inconsistent Emissions – coordinate with CAPCOA

17. Point Sources for Microscale Modeling (cont’d) • Facility-centered “mini-grids” for ISCST3 • Individual facility-centered grids for point sources • Fine grid (100m x 100m) out to 3 km • Coarse grid (500m x 500m) from 3 km out to 10 km • Generally use ISC regulatory options • Initially model as Urban land use • Complex terrain poses concerns • Batch automation tools • Manage by 20 km tiles

18. Microscale Modeling for Statewide Application • Domain • Sparse “mini-grid” concept • Meteorology • Emissions and Modeling • Point Sources • Off-road Diesel (“Complex point sources”) • On-road, Link-Based Sources • Integration, risk, and display tools

19. Off-Road & “Complex Point Sources” for Microscale Modeling • On-site, mobile diesel • Dedicated equipment (cranes, forklifts, movers…) • May dominate impacts • “Complex point sources” • Associate on-site mobile diesel with a facility • Historically in areawide inventory; spatial surrogates • Identify key source types • Exploring ports, airports, distribution centers, railyards

20. Microscale Modeling for Statewide Application • Domain • Sparse “mini-grid” concept • Meteorology • Emissions and Modeling • Point Sources • Off-road Diesel (“Complex point sources”) • On-road, Link-Based Sources • Integration, risk, and display tools

21. On-Road Sources for Microscale Modeling • 2-Part Approach to Roadway Modeling • “Major” roads modeled along road links • Remaining roads handled in regional grid model • Propose to use ISC -- area releases along links • U.S. EPA approach in “Example Application of Modeling Air Toxics in an Urban Area” • Restrict links to 100:1 length:width ratio • Limitation: turbulence; Strength: single model

22. On-Road Sources for Microscale Modeling (cont’d) • Multistep approach to link-based emissions • Local COG networks or State Travel Model network • DTIM to allocate EMFAC “control totals” to grid cells • Single input projection for DTIM files • For “major” roadways, apportion grid cell totals to HPMS links by traffic count data • Reasonable locational accuracy with HPMS network • Use EMFAC “control totals” to ensure conformity

23. Microscale Modeling for Statewide Application • Domain • Sparse “mini-grid” concept • Meteorology • Emissions and Modeling • Point Sources • Off-road Diesel (“Complex point sources”) • On-road, Link-Based Sources • Integration, risk, and display tools

24. Tools to Support Statewide Risk Modeling/Mapping at ARB • Modeling Automation and Integration, and Risk Estimation Tools -- Batch Processor • Tools to automate microscale model runs for sources • Concept: sparse “mini-grid” approach -- can build individual source-centered grids for microscale modeling • Concept: universal statewide grid (mesh) • Overlay tools to integrate coarse regional grid and microscale grids • Automate Link-based modeling for major roadways • Incorporate HARP risk tools & CHAPIS visualization tools

25. Risk and Mapping Tools for Statewide Application • Risk Assessment • HARP risk tools • Cancer and chronic non-cancer initially • OEHHA “minimum pathways” • Inhalation, soil, and dermal exposure • Deposition rates in OEHHA Guidance Manual • Adapt CHAPIS web-mapping tool (currently cumulative emissions), to also display gridded risk • Continue designing future analysis tools • Risk Assessment • HARP risk tools • Cancer and chronic non-cancer initially • OEHHA “minimum pathways” • Inhalation, soil, and dermal exposure • Deposition rates in OEHHA Guidance Manual • Adapt CHAPIS web-mapping tool (currently cumulative emissions), to also display gridded risk • Continue designing future analysis tools

26. SUMMARY • Improved information to the public • CHAPIS emission maps • Ultimately risk maps • Improved tools for air quality professionals • To assess localized cumulative impacts • Improved tools for total cumulative impacts • Localized impacts and regional perspectives on risk • Peer reviewed protocols • On-going process

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