1. 1 DRAFT Report for Air Quality Analysis on Cumulative Emissions, Barrio Logan Tony Servin, P.E. Modeling Support Section Planning and Technical Support Division March 16, 2004 Air Resources Board California Environmental Protection Agency BLRprtStatus_VerC_031604.ppt

2. 2 Preliminary Draft Report For Discussion Purposes Only Do Not Cite - Do Not Quote Simultaneous Internal ARB Review Purpose is to provide an opportunity for the Working Group to review before we complete a final report.

3. 3 Barrio Logan - Location

4. 4 Field Studies in Barrio Logan  Ambient Toxics Monitoring  17 Months, Oct 99 - Feb 01  Hexavalent Chromium Monitoring  Dec 01 - May 02  Tracer Studies  Aug 01 and Dec 01  Tracer and Toxics Monitoring (CE-CERT)  Dec 01 - Jan 02  Trailer Tracer Study at UCR (CE-CERT)  June 01

5. 5 Modeling Approach to Estimate Cumulative Risk

6. 6 Regional Modeling - Domain SCOS domain (87 x 67 ; 4 km grid ) Larger than MATES II San Diego Riverside Los Angeles San Bernardino Ventura Orange Mexico Regional Modeling Integrated Results Risk Assessment Mapping and Visualization Microscale Modeling Emissions and Meteorology Microscale modeling domain

7. 7 Regional Modeling - Parameters Two Regional Air Quality Models –CALGRID (run for 12 months in 1998) –CMAQ (one month per season - January, April, August, and November) Two meteorological models run for 1998 –CALMET (data from over 200 sites) –MM5 SAPRC99 for atmospheric chemistry –Explicit reactions for reactive toxics Boundary conditions based on SCOS97 Emissions –SCOS97 adjusted to 1998 –Seasonal inventories (weekday/weekend) –Latest profiles, surrogates, and EMFAC2000

8. 8 1,3 Butadiene Benzene Formaldehyde Diesel Exhaust PM Modeled Annual Average Concentrations

9. 9 Predicted annual avgs. are ±50% of observations for benzene, toluene, formaldehyde, acetaldehyde Performance comparable with other studies (e.g., MATES II) Ozone performance as good or better than a previous annual ozone modeling study 3 species contribute over 90% of estimated inhalation risk (PM Diesel exhaust, benzene, and 1,3-butadiene) over the domain Poor performance for some species (e.g., vinyl chloride, ethylene oxide, some PM components, and xylenes. However, these species are a minor contributor to the overall inhalation risk.) In Barrio Logan, the models are not sensitive to double counting (< 1%) Conclusions - Regional Modeling

10. 10 Microscale Modeling Domain 15-km x 15--km domain Nested domain (3.5-km x 2.5-k m) of receptors with a 50 m spacing Modeling Period: October 1999 - October 2000

11. 11 Point Sources - Aerial View Local Sources Facilities Point and Volume Sources Rail Line Volume Sources Shipping Lane Volume Sources Logan Memorial

12. 12 MV Sources - Aerial View Input to CALINE 991 Links from DTIM

13. 13 Emission Inventory Summary Over 200 facilities visited Major point sources accounted for most of emissions in point source inventory Small facilities need to be assessed for cumulative & proximity effects (e.g., chrome plating) Mobile sources account for most diesel PM, benzene, and formaldehyde emissions

14. 14 Conclusions - Microscale Modeling Diesel exhaust PM is the major contributor to inhalation risk Estimated risk is highly localized, dropping off rapidly within a few hundred meters from source Microscale modeling only show effect of local emissions ISC/CALINE underpredicts at Memorial Academy due to the overwhelming regional emissions influence. The estimated risk at a facility is similar to the HRA risk estimated by the Hot Spots program

15. 15 Observations, Regional, and Microscale Model Results Microscale Modeling Regional Modeling Observations Preliminary Draft

16. 16 Inhalation risk is calculated with the appropriate Unit Risk Factor in the OEHHA guidelines. Adjustments for multipathway pollutants or exposure to micro-environments is not included in this analysis. Risk Assessment

17. 17 Preliminary Draft

18. 18

19. 19 Preliminary Draft Report For Discussion Purposes Only Do Not Cite - Do Not Quote Simultaneous Internal ARB Review Purpose is to provide an opportunity for the Working Group to review before we complete a final report.