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August 4, 1999. Workshop to Discuss Draft Proposals for Changes to the Predictive Model and Other Changes to the California Reformulated Gasoline Regulations. California Environmental Protection Agency. Air Resources Board. Agenda . Introductions ARB Presentation Background
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August 4, 1999 Workshop to Discuss Draft Proposals for Changes to the Predictive Model and Other Changes to the California Reformulated Gasoline Regulations California Environmental Protection Agency Air Resources Board
Agenda • Introductions • ARB Presentation • Background • Technical Issues • Draft Preliminary Proposal • Presentations by Others • Open Discussion • Other Issues • High Emitters • Schedule • Closing Remarks
Background • Governor Davis’s Executive Order for the Phase-Out of MTBE
Governor’s Findings Based on study by University of California, and public hearings Governor found: • MTBE presents threat to groundwater, surface water, and drinking water • Underground gasoline storage tanks are not leak proof • MTBE is highly soluble in water and transfers to groundwater faster than other constituents in gasoline • MTBE in small amounts renders drinking water unusable • MTBE potential but not proven health problem • MTBE not essential to cleaner-burning gasoline
Governor’s Executive Order • On March 26, 1999 Governor issued Executive Order D-5-99 for the phase-out of MTBE from California Gasoline
Governor’s Executive Order(D-5-99) • Requires phase out of MTBE by earliest practical date but not later than December 31, 2002 • To be implemented by several organizations • Air Resources Board • State Water Resources Control Board (SWRCB) • Office of Environmental Health Hazard Assessment • California Energy Commission (CEC) • Department of Health Services (DHS)
Tasks Required by Executive Order D-5-99 • CEC with ARB to develop timetable for removal of MTBE (Hearing - June 28, 1999) • ARB to evaluate need for winter oxygenates in Lake Tahoe (Hearing - June 24,1999) • CEC with ARB to work with petroleum industry to provide MTBE-free gasoline to Lake Tahoe region • ARB 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)
Tasks Required by Executive Order D-5-99 (continued) • ARB to adopt regulations requiring prominent labeling of gasoline with MTBE at the pump (Hearing - June 24, 1999) • ARB and the SWRCB to conduct environmental fate and transport analysis of ethanol • OEHHA to prepare an analysis of the health risks associated with the use of ethanol
Tasks Required by Executive Order D-5-99 (continued) • SWRCB with the Department of Water Resources and DHS to: • Prioritize vulnerable water areas • Prioritize resources to protection and cleanup • Develop guidelines for investigation and cleanup of MTBE • SWRCB to seek legislation to extend sunset date of Underground Storage Tank Cleanup Fund to December 31, 2010
Tasks Required by Executive Order D-5-99 (continued) • CEC to evaluate steps to foster waste-based or other biomass ethanol development in California if ethanol acceptable substitute for MTBE
Summer Test Program • Finished by early Fall ? • Advanced technology vehicles • Three sulfur levels (5, 30, 100) • Three oxygen levels (0, 2.0, 3.5) • Non-FTP test cycle
Predictive Model Development • Tech Groups 3 and 4 - Calculate new coefficients • Tech Group 5 - Build new model • Sulfur Response - Log sulfur curve • Toxics Model
Predictive Model Development • Evaporative Emissions Model • CO Credit • EMFAC7f -vs- EMFAC99
Potential Changes from the Existing Model • More exhaust data available • Tech Group 3 - A small change to coefficients because of new data • Tech Group 4 - A small change to coefficients because of new data • Tech Group 5 - The new model being developed relies on Tech Group 4 model parameters responses and new data • CO Credit for oxygen above 2% • An evaporative hydrocarbon model • Hot Soak • Running Loss • Diurnal and Resting Losses
Year 2005 - Percent Distribution Tech Model Vehicles VMT Exhst Evap Total NOx CO Group Years ROG ROG ROG 5 96 - 05 68 79 25 27 26 50 36 4 86 – 95 26 18 45 52 47 33 38 3 81 – 85 4 2 14 10 13 12 12 2 - 1 71 – 80 2 1 17 11 15 5 14 EMFAC7f
CO * 42 44 14 Draft Relative Tech Group Weighting for Phase 3 RFG (2005) Tech Group ROG * NOx * 5 30 53 4 54 35 3 17 12 * Need to update based on new EMFAC model.
Predictive Model Update Issues • Toxics Model • Evap toxics model for benzene. • NOx Model - Olefin/T90 • Hydrocarbon Model • Exhaust Model + Evap Model +CO Credit (oxy>2%) • MIR Factors • EMFAC7g/EMFAC99
Phase 2 RFG Parameters and Preliminary Draft Phase 3 RFG Options N/A - Not Applicable, TBD - To Be Determined
Near Term WorkFor August 31, 1999, Workshop • Further address flexibility • Add CO credit for oxygen > 2% • Refine Predictive Model
Midterm WorkTo be completed by October 1999 • Update Predictive Model with new data • Availability of new emissions inventory model - EMFAC99
What is the Basis of the Predictive Model? • Data from 20 different test programs that investigated the effects of fuel properties on emissions • Over 1000 vehicles tested • About 6900 data points • Over 200 fuels
Differences Between the EPA and CARB Models EPA Complex Model • Exhaust component - includes separate normal and higher emitter elements • Evaporative component - RVP allowed to vary ARB Predictive Model • Exhaust only - RVP fixed in regulations • Normal and higher emitters modeled together • Gives larger hydrocarbon credit for increased Oxygen
How does the Predictive Model Differ from the U.S. EPA Complex Model?- High Emitters - • U.S. EPA Complex Model • Has high emitter element • High emitter element developed from data from only 32 vehicles. • ARB Predictive Model • Predictive Model includes high emitters as part of random on-road fleet sample. • ARB staff found that the lack of stability in the high emitters was consistent with the conclusions of the Auto/Oil Study.
Differences Between the EPA and CARB Models ARB PM EPA CM Data Points 6900 5300 Number of Veh 1100 512 960 (normal) 480 (normal) 140 (high) 32 (high) Number of Fuels 250 200 Vehicle Types CA certified 1990 MY Tech (1981-1991 MY)
Percent Change in HC Emissions 0 Percent to 3.5 Percent Oxygen ARB Predictive Model
Percent Change in NOx Emissions 0 Percent to 3.5 Percent Oxygen ARB Predictive Model
High Emitters • Predictive Model Database • 140 High Emitters (Ave. > 2 x Standard) • 960 Normal Emitters • Auto/Oil AQIRP High Emitter Test Program • Tested high emitters • Determined 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. • U.S. EPA Database shows large test to test variability • Continue to be investigated
EPA Data for High Emitters is Highly Variable Avg. THC Emissions Diff. (gm/mi) Avg. NOx Emissions Diff. (gm/mi)
Near Term WorkFor August 31, 1999, Workshop • Add flexibility to initial draft proposal • Add CO credit for oxygen > 2% • Refine Predictive Model
Next Meeting - Proposed • August 31, 1999 • 10 am to 4 pm • ARB facilities in El Monte