FINAL1 Inventory, Emissions, and Population July 2, 2003 AIR, Inc.

FINAL2 Overview Exhaust Emissions Evaporative Emissions Populations

FINAL3 Materials Received/Utilized from ARB Population and Activity MemoApril 14 Hot soak RVP dataApril 15 Evaporative Spreadsheets (preliminary)April 17 Evaporative Emissions MemoApril 21 Tier 3 Exhaust Emission FactorsMay 1 Lifetime emissions and cost effectivenessJune 5 Equipment Survey DataJune 8 Total inventoriesJune 26 Cost effectiveness model/assumptionsJune 30 Inventories split by exhaust vs evaporativeJuly 1 Audit data analysis??

FINAL4 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

FINAL5 Premium Program What is it? Performance OFFROAD assumptions Lifetime emission impacts Summary

FINAL6 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

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

FINAL10 OFFROAD Model Also does not include the effects of the Premium Program –Districts have not been able to book these reductions

FINAL11 Tier 3 Lifetime HC + NOx Reductions Per Unit (lbs)

FINAL12 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

FINAL13 Summary - Exhaust Emissions ARB should revise its Tier 2 baseline for estimating proposed Tier 3 cost effectiveness OFFROAD model should be revised

FINAL14 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

FINAL15 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

FINAL16 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

FINAL17 Ratio of Lawnmower Emissions at Different Ages to Emissions at Zero Hour DiurnalRestingHot SoakRunning Evap Component Ratio of Emissions Zero Hour Used Old

FINAL18 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

FINAL19 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

FINAL20 Baseline Evaporative HC Lifetime Emissions Per Unit (lbs)

FINAL21 Tier 3 Evap HC Reductions Per Unit (lbs)

FINAL22 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

FINAL23 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

FINAL24 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 Pop state = Pop suvey x 11.5 million/2200 Problem: Survey overweighted single detached residences, which have a higher equipment ownership

FINAL25 Fraction of Residence Types

FINAL26 Equipment Per Residence

FINAL27 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

FINAL28 Summary - Population ARB proposed populations should be revised to match Census residence demographics

FINAL29 Summary Exhaust –Tier 2 baseline emissions should include Premium Program Evaporative –Size of inventory and reductions uncertain Population –Too high