Inventory, Emissions, and Population

1. Inventory, Emissions, and Population July 2, 2003 AIR, Inc. FINAL

2. Overview • Exhaust Emissions • Evaporative Emissions • Populations FINAL

3. Materials Received/Utilized from ARB Population and Activity Memo April 14 Hot soak RVP data April 15 Evaporative Spreadsheets (preliminary) April 17 Evaporative Emissions Memo April 21 Tier 3 Exhaust Emission Factors May 1 Lifetime emissions and cost effectiveness June 5 Equipment Survey Data June 8 Total inventories June 26 Cost effectiveness model/assumptions June 30 Inventories split by exhaust vs evaporative July 1 Audit data analysis ?? FINAL

4. Exhaust Emissions • Major comment is that the baseline does not reflect the Premium Program • baseline is used to determine cost effectiveness of proposed Tier 3 exhaust standards FINAL

5. Premium Program • What is it? • Performance • OFFROAD assumptions • Lifetime emission impacts • Summary FINAL

6. What is it? • 1999 exhaust proposal included Tier 2 and Tier 3 • Tier 2 implemented in 2000, Tier 3 was to be implemented in 2004 • Final rule included Tier 2 and Premium Program • Premium Program covered the emission reductions of Tier 3 • Briggs and Stratton and Tecumseh were participants FINAL

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9. Premium Program • Data show 2002 emissions lower than assumed in some analyses FINAL

10. OFFROAD Model • Also does not include the effects of the Premium Program • Districts have not been able to book these reductions FINAL

11. Tier 3 Lifetime HC + NOx Reductions Per Unit (lbs) FINAL

12. Tier 3 Exhaust Cost Effectiveness • Residential Lawnmower • Assumes ARB standards implemented as proposed • Exhaust cost increase: $54 (Briggs and Stratton) • Preliminary estimate: $44,000 per ton of HC+NOx FINAL

13. Summary - Exhaust Emissions • ARB should revise its Tier 2 baseline for estimating proposed Tier 3 cost effectiveness • OFFROAD model should be revised FINAL

14. Evaporative Emissions • Concerns: • Baseline and control diurnal and resting losses overestimated • Baseline running loss deterioration too high • RVP effect for hot soak and running losses too large • Running loss reductions depend on technology used FINAL

15. Diurnal and Resting Losses • ARB definition of evap processes in OFFROAD model: they cannot overlap • However, for ARB’s lifetime emission reductions and cost-effectiveness, they do overlap (“partial” diurnals) • This results in some double-counting of emissions • This will be addressed in soon-to-be released OFFROAD model, but is not yet addressed in ARB’s lifetime emissions, inventories, or cost/effectiveness • Small effect for residential equipment, significant for commercial • Could not address magnitude of this effect for workshop FINAL

16. Running Loss Deterioration • Diurnal, resting loss and hot soak emissions for lawnmowers estimated on 23 lawnmowers • New, Used, Old • Running losses estimated on only 4 lawnmowers • Running loss deterioration not consistent with other evap components • One Alternative: use deterioration on other components to predict running loss deterioration • Similar concern for other equipment FINAL

17. Ratio of Lawnmower Emissions at Different Ages to Emissions at Zero Hour 18.00 16.00 Zero Hour 14.00 Used 12.00 Old 10.00 Ratio of Emissions 8.00 6.00 4.00 2.00 0.00 Diurnal Resting Hot Soak Running Evap Component FINAL

18. Hot Soak and Running Loss RVP Effect • ARB developed RVP effect at 95F and is applying it at all temperatures • Annual RVP assumed (8.1) may not reflect seasonal activity differences • RVP does not have same effect at all temperatures • Increases baseline and controlled emissions by same percentage (25%), so benefit of controls is also larger • One alternative is to eliminate this effect FINAL

19. Running Loss Reductions • ARB estimated at 50% • test data indicates 42% • New lawnmower percent reduction will not apply when equipment older • Should use g/hr reduction on new engines at all ages • Also, reductions depend on control technology used • Pressurized system with TPCV only gets permeation benefit, because pressure controls have to be “open” when engine running • Canister controls would get permeation + vapor benefit, since canister is connected to tank during engine operation - no data FINAL

20. Baseline Evaporative HC Lifetime Emissions Per Unit (lbs) FINAL

21. Tier 3 Evap HC Reductions Per Unit (lbs) FINAL

22. Population and Activity • Evaluated population and activity changes • Why discuss this? • Population/activityinventoriestargets for alternatives • Activityproportion of evap vs exhaust • Concern • Populations must be consistent with Census data FINAL

23. Populations • ARB conducted equipment survey • Survey is being used to update populations • Large proposed changes in populations • Lawnmowers: 2.4 million to 4 million • Chainsaws: 0.6 million to 2.1 million • Trimmers/edgers: 0.8 million to 2.8 million • Inventories based on these new populations appear in the SCAQMD SIP FINAL

24. Survey and Method • 15,000 surveys sent • 2200 responded to survey (<15%) • 220 agreed to use data loggers (<2%) • Equipment populations were determined in the 2200 households • Total California households were determined: 11.5 million • Popstate = Popsuvey x 11.5 million/2200 • Problem: Survey overweighted single detached residences, which have a higher equipment ownership FINAL

25. Fraction of Residence Types FINAL

26. Equipment Per Residence FINAL

27. Survey • These tables indicate that sample must be re-weighted by Census residence type fractions • This will have a significant effect on populations, and therefore, inventories FINAL

28. Summary - Population • ARB proposed populations should be revised to match Census residence demographics FINAL

29. Summary • Exhaust • Tier 2 baseline emissions should include Premium Program • Evaporative • Size of inventory and reductions uncertain • Population • Too high FINAL