PM2.5 Working Group PM2.5 Working Group Meeting #2Meeting #2

South Coast Air Quality Management DistrictSouth Coast Air Quality Management District

July 11, 2006July 11, 2006

Update on CEIDARS ListUpdate on CEIDARS List

• Contacted CARBContacted CARB Redundant categories represent different Redundant categories represent different

years, i.e., before & after regulations in effectyears, i.e., before & after regulations in effect Includes implementation of ULSD Includes implementation of ULSD

requirementsrequirements Developing a list without redundancyDeveloping a list without redundancy CARB Considering revising list at county level CARB Considering revising list at county level

Update on CEIDARS List Update on CEIDARS List (Cont.)(Cont.)

• Staff Recommendations:Staff Recommendations: Staff will prepare a general list based on Staff will prepare a general list based on

AQMP inventory categories with a few AQMP inventory categories with a few more detailed categoriesmore detailed categories

Other PM2.5 data can be used, e.g., Other PM2.5 data can be used, e.g., project or site-specific dataproject or site-specific data

Staff will update list as information Staff will update list as information becomes availablebecomes available

Preliminary Results of PM2.5 Preliminary Results of PM2.5 LST AnalysisLST Analysis

• Initial recommendation for PM2.5 Initial recommendation for PM2.5 construction LST assumed little contribution construction LST assumed little contribution from construction combustion sourcesfrom construction combustion sources

• Working group member modeling results Working group member modeling results presented at 6/8/06 meeting appeared to presented at 6/8/06 meeting appeared to show large contribution from combustion show large contribution from combustion sourcessources

• Staff modeled PM2.5 emissions using LST Staff modeled PM2.5 emissions using LST construction scenarios construction scenarios

Preliminary Results of PM2.5 Preliminary Results of PM2.5 LST Analysis (Cont.)LST Analysis (Cont.)

• Modeling showed:Modeling showed: Construction equipment combustion Construction equipment combustion

emissions contribute ~75% - 100%emissions contribute ~75% - 100% Contribution of fugitive sources dependant on Contribution of fugitive sources dependant on

construction phaseconstruction phase Demolition & site preparation have highest Demolition & site preparation have highest

fugitive dust contributionsfugitive dust contributions Construction & asphalt paving phases have Construction & asphalt paving phases have

highest construction combustion contributionshighest construction combustion contributions

Preliminary Results of PM2.5 Preliminary Results of PM2.5 LST Analysis (Cont.)LST Analysis (Cont.)

• Staff recommendationsStaff recommendations Revise PM2.5 construction LST from 2.5 Revise PM2.5 construction LST from 2.5 µµg/mg/m33 to 10.4 to 10.4 µµg/mg/m33

No changes to any other staff No changes to any other staff recommendationsrecommendations

Exceedance of either PM10 or PM2.5 Exceedance of either PM10 or PM2.5 construction LST is a significant localized air construction LST is a significant localized air quality impactquality impact

Mitigation Options to Reduce Mitigation Options to Reduce PM2.5 EmissionsPM2.5 Emissions

• Mitigation to reduce fugitive PM2.5 same as Mitigation to reduce fugitive PM2.5 same as for fugitive PM10:for fugitive PM10: Watering 2 – 3 times per day (control efficiency Watering 2 – 3 times per day (control efficiency

[CE] = 50% – 68%)[CE] = 50% – 68%) Chemical dust suppressants (CE = 65%)Chemical dust suppressants (CE = 65%) Enclose & water exposed piles (CE = 74%)Enclose & water exposed piles (CE = 74%)

• Apply mitigation CEs only to fugitive dust Apply mitigation CEs only to fugitive dust portion of PM2.5 estimateportion of PM2.5 estimate

Mitigation Options to Reduce Mitigation Options to Reduce PM2.5 Emissions (Cont.)PM2.5 Emissions (Cont.)

Alt. Diesel FuelAlt. Diesel Fuel NOx CENOx CEaa PM CEPM CEaa

AquazoleAquazole 16%16% 60%60%

Emulsified Emulsified DieselDiesel 15%15% 58%58%

OO22-Diesel-Diesel 1.6%1.6% 20%20%

• Keep engines properly tuned, PM CE of 5%Keep engines properly tuned, PM CE of 5%

aa Percent reduction based on PM10 Percent reduction based on PM10

Mitigation Options to Reduce Mitigation Options to Reduce PM2.5 Emissions (Cont.)PM2.5 Emissions (Cont.)

• Operation on-road mitigation consistent Operation on-road mitigation consistent with CARB-verified technologieswith CARB-verified technologies Level 1 Level 1 >> 25 % reduction in particulates 25 % reduction in particulates Level 2 Level 2 >> 50 % reduction in particulates 50 % reduction in particulates Level 3 Level 3 >> 85 % reduction in particulates 85 % reduction in particulates

(Note: % reduction based on PM10)(Note: % reduction based on PM10)

• List of CARB-verified technologies at:List of CARB-verified technologies at: www.arb.ca.gov/verdev/verifiedtechnologies/cvt.htmwww.arb.ca.gov/verdev/verifiedtechnologies/cvt.htm

ScheduleSchedule

• Comments on revised proposal due Comments on revised proposal due 7/26/067/26/06

• Presentation to Mobile Source Committee Presentation to Mobile Source Committee 7/28/067/28/06

• Public Workshop August 9, 2006Public Workshop August 9, 2006• Recommendations to Governing Board Recommendations to Governing Board

Meeting on September 8, 2006Meeting on September 8, 2006