Workshop to Discuss Draft Proposals for Changes to the Predictive Model and Other Changes to the California Reformulated Gasoline Regulations August 4, 1999 California Environmental Protection Agency Air Resources Board

2 Agenda zIntroductions zARB Presentation yBackground yTechnical Issues yDraft Preliminary Proposal zPresentations by Others zOpen Discussion zOther Issues yHigh Emitters ySchedule zClosing Remarks

3 Background zGovernor Davis’s Executive Order for the Phase-Out of MTBE

4 Governor’s Findings zMTBE presents threat to groundwater, surface water, and drinking water yUnderground gasoline storage tanks are not leak proof yMTBE is highly soluble in water and transfers to groundwater faster than other constituents in gasoline yMTBE in small amounts renders drinking water unusable zMTBE potential but not proven health problem zMTBE not essential to cleaner-burning gasoline Based on study by University of California, and public hearings Governor found:

5 Governor’s Executive Order zOn March 26, 1999 Governor issued Executive Order D-5-99 for the phase-out of MTBE from California Gasoline

6 Governor’s Executive Order (D-5-99) zRequires phase out of MTBE by earliest practical date but not later than December 31, 2002 zTo be implemented by several organizations yAir Resources Board yState Water Resources Control Board (SWRCB) yOffice of Environmental Health Hazard Assessment yCalifornia Energy Commission (CEC) yDepartment of Health Services (DHS)

7 Tasks Required by Executive Order D-5-99 zCEC with ARB to develop timetable for removal of MTBE (Hearing - June 28, 1999) zARB to evaluate need for winter oxygenates in Lake Tahoe (Hearing - June 24,1999) zCEC with ARB to work with petroleum industry to provide MTBE-free gasoline to Lake Tahoe region zARB to adopt Phase 3 gasoline regulations to provide additional flexibility in removing oxygen while preserving benefits and allow compliance with the State Implementation Plan (SIP)

8 Tasks Required by Executive Order D-5-99 (continued) zARB to adopt regulations requiring prominent labeling of gasoline with MTBE at the pump (Hearing - June 24, 1999) zARB and the SWRCB to conduct environmental fate and transport analysis of ethanol zOEHHA to prepare an analysis of the health risks associated with the use of ethanol

9 Tasks Required by Executive Order D-5-99 (continued) zSWRCB with the Department of Water Resources and DHS to: yPrioritize vulnerable water areas yPrioritize resources to protection and cleanup yDevelop guidelines for investigation and cleanup of MTBE zSWRCB to seek legislation to extend sunset date of Underground Storage Tank Cleanup Fund to December 31, 2010

10 Tasks Required by Executive Order D-5-99 (continued) zCEC to evaluate steps to foster waste-based or other biomass ethanol development in California if ethanol acceptable substitute for MTBE

11 Technical Issues

12 Summer Test Program zFinished by early Fall ? zAdvanced technology vehicles zThree sulfur levels (5, 30, 100) zThree oxygen levels (0, 2.0, 3.5) zNon-FTP test cycle

13 Issues

14 Predictive Model Development zTech Groups 3 and 4 - Calculate new coefficients zTech Group 5 - Build new model zSulfur Response - Log sulfur curve zToxics Model

15 Predictive Model Development zEvaporative Emissions Model zCO Credit zEMFAC7f -vs- EMFAC99

16 Potential Changes from the Existing Model zMore exhaust data available yTech Group 3 - A small change to coefficients because of new data yTech Group 4 - A small change to coefficients because of new data yTech Group 5 - The new model being developed relies on Tech Group 4 model parameters responses and new data zCO Credit for oxygen above 2% zAn evaporative hydrocarbon model yHot Soak yRunning Loss yDiurnal and Resting Losses

17 Changes to Database

18 Year Percent Distribution TechModelVehiclesVMTExhstEvapTotalNOxCO GroupYearsROGROGROG – – – EMFAC7f

19 Draft Relative Tech Group Weighting for Phase 3 RFG (2005) 30 ROG * NOx * Tech Group CO * * Need to update based on new EMFAC model.

20 Predictive Model Update Issues zToxics Model yEvap toxics model for benzene. zNOx Model - Olefin/T90 zHydrocarbon Model yExhaust Model + Evap Model +CO Credit (oxy>2%) yMIR Factors yEMFAC7g/EMFAC99

21 Proposed Draft Specifications

22 Phase 2 RFG Parameters and Preliminary Draft Phase 3 RFG Options N/A - Not Applicable, TBD - To Be Determined

23 Near Term Work For August 31, 1999, Workshop zFurther address flexibility zAdd CO credit for oxygen > 2% zRefine Predictive Model

24 Midterm Work To be completed by October 1999 zUpdate Predictive Model with new data zAvailability of new emissions inventory model - EMFAC99

26 High Emitters

27 What is the Basis of the Predictive Model? zData from 20 different test programs that investigated the effects of fuel properties on emissions zOver 1000 vehicles tested zAbout 6900 data points zOver 200 fuels

28 Differences Between the EPA and CARB Models EPA Complex Model yExhaust component - includes separate normal and higher emitter elements yEvaporative component - RVP allowed to vary ARB Predictive Model yExhaust only - RVP fixed in regulations yNormal and higher emitters modeled together yGives larger hydrocarbon credit for increased Oxygen

29 How does the Predictive Model Differ from the U.S. EPA Complex Model? - High Emitters - zU.S. EPA Complex Model yHas high emitter element yHigh emitter element developed from data from only 32 vehicles. zARB Predictive Model yPredictive Model includes high emitters as part of random on-road fleet sample. yARB staff found that the lack of stability in the high emitters was consistent with the conclusions of the Auto/Oil Study.

30 Differences Between the EPA and CARB Models ARB PMEPA CM Data Points Number of Veh (normal)480 (normal) 140 (high)32 (high) Number of Fuels Vehicle TypesCA certified1990 MY Tech ( MY)

31 Percent Change in HC Emissions 0 Percent to 3.5 Percent Oxygen ARB Predictive Model

32 Percent Change in NOx Emissions 0 Percent to 3.5 Percent Oxygen ARB Predictive Model

33 High Emitters zPredictive Model Database y140 High Emitters (Ave. > 2 x Standard) y960 Normal Emitters zAuto/Oil AQIRP High Emitter Test Program yTested high emitters yDetermined large test-to-test variability, concluded that when test to test variability is accounted for, high emitters have similar response to oxygen as normal emitters. zU.S. EPA Database shows large test to test variability zContinue to be investigated

34 EPA Data for High Emitters is Highly Variable Avg. THC Emissions Diff. (gm/mi) Avg. NOx Emissions Diff. (gm/mi)

36 Near Term Work For August 31, 1999, Workshop zAdd flexibility to initial draft proposal zAdd CO credit for oxygen > 2% zRefine Predictive Model

37 Next Meeting - Proposed zAugust 31, 1999 z10 am to 4 pm zARB facilities in El Monte