1. PM2.5 Working Group Meeting #2 South Coast Air Quality Management District July 11, 2006

2. Update on CEIDARS List Contacted CARB Contacted CARB  Redundant categories represent different years, i.e., before & after regulations in effect  Includes implementation of ULSD requirements  Developing a list without redundancy  CARB Considering revising list at county level

3. Update on CEIDARS List (Cont.) Staff Recommendations: Staff Recommendations:  Staff will prepare a general list based on AQMP inventory categories with a few more detailed categories  Other PM2.5 data can be used, e.g., project or site-specific data  Staff will update list as information becomes available

4. Preliminary Results of PM2.5 LST Analysis Initial recommendation for PM2.5 construction LST assumed little contribution from construction combustion sources Initial recommendation for PM2.5 construction LST assumed little contribution from construction combustion sources Working group member modeling results presented at 6/8/06 meeting appeared to show large contribution from combustion sources Working group member modeling results presented at 6/8/06 meeting appeared to show large contribution from combustion sources Staff modeled PM2.5 emissions using LST construction scenarios Staff modeled PM2.5 emissions using LST construction scenarios

5. Preliminary Results of PM2.5 LST Analysis (Cont.) Modeling showed: Modeling showed:  Construction equipment combustion emissions contribute ~75% - 100%  Contribution of fugitive sources dependant on construction phase  Demolition & site preparation have highest fugitive dust contributions  Construction & asphalt paving phases have highest construction combustion contributions

6. Preliminary Results of PM2.5 LST Analysis (Cont.) Staff recommendations Staff recommendations  Revise PM2.5 construction LST from 2.5 µg/m 3 to 10.4 µg/m 3  No changes to any other staff recommendations  Exceedance of either PM10 or PM2.5 construction LST is a significant localized air quality impact

7. Mitigation Options to Reduce PM2.5 Emissions Mitigation to reduce fugitive PM2.5 same as for fugitive PM10: Mitigation to reduce fugitive PM2.5 same as for fugitive PM10:  Watering 2 – 3 times per day (control efficiency [CE] = 50% – 68%)  Chemical dust suppressants (CE = 65%)  Enclose & water exposed piles (CE = 74%) Apply mitigation CEs only to fugitive dust portion of PM2.5 estimate Apply mitigation CEs only to fugitive dust portion of PM2.5 estimate

8. Mitigation Options to Reduce PM2.5 Emissions (Cont.) Alt. Diesel Fuel NOx CE a PM CE a Aquazole16%60% Emulsified Diesel 15%58% O 2 -Diesel 1.6%20% Keep engines properly tuned, PM CE of 5% Keep engines properly tuned, PM CE of 5% a Percent reduction based on PM10

9. Mitigation Options to Reduce PM2.5 Emissions (Cont.) Operation on-road mitigation consistent with CARB-verified technologies Operation on-road mitigation consistent with CARB-verified technologies  Level 1 > 25 % reduction in particulates  Level 2 > 50 % reduction in particulates  Level 3 > 85 % reduction in particulates (Note: % reduction based on PM10) List of CARB-verified technologies at: List of CARB-verified technologies at:  www.arb.ca.gov/verdev/verifiedtechnologies/cvt.htm

10. Schedule Comments on revised proposal due 7/26/06 Comments on revised proposal due 7/26/06 Presentation to Mobile Source Committee 7/28/06 Presentation to Mobile Source Committee 7/28/06 Public Workshop August 9, 2006 Public Workshop August 9, 2006 Recommendations to Governing Board Meeting on September 8, 2006 Recommendations to Governing Board Meeting on September 8, 2006