technical review workshop report technical oversight committee for the wrap board meeting – july...

Technical Review Workshop Report

Technical Oversight Committee

for the

WRAP Board Meeting – July 24, 2002


Presentation Objectives Organization & content of the workshop Key results Next steps


Guidelines for §309 Analyses Control strategies already prescribed Technical analyses measure the benefits of these strategies

Workshop Statistics Over 100 people in attendance Representatives from 13 western states, plus tribes Members of 3 other Regional Planning Organizations Cross-section of federal and local officials


Workshop Topics Introduction/review of regional haze & ambient

data trends Emission Inventory overview, followed by details of

point, area, mobile, and fire Control Strategy Modeling overview, followed by

details of modeling process and performance Future work to complete §309 analyses, and list of

improvements for §308 work


Emissions Forum Stationary Point Sources Inventory Area Sources Inventory

Mobile Sources Forum On-Road Mobile Sources Inventory (tailpipe, evaporative, tire

and brake wear emissions) Off-Road Mobile Sources Inventory (tailpipe and evaporative

emissions only)

Fire Emissions Joint Forum Wildfire Inventory Prescribed Fire Inventory (Rx) Agricultural Fire Inventory


Changes in emissions for the WRAP region between 1996 base case & 2018 Annex Milestone inventories: VOC down 29% NOx down 31% CO down 29% SO2 down 17%

PM10 up 4%

PM2.5 up 5%

NH3 up 9%


Modeling analyses: Anticipate planned national/state/local emissions

reductions programs Then proceed with evaluation of control strategies

Modeling results show visibility improving Annex milestones are better than command & control for

15 of the 16 GCVTC Class I Areas Same or better at all other Class I Areas, with 1 exception,

in and around the WRAP regionA great deal of modeling and other technical work has been done, particularly in the last yearWork is continuing to analyze, understand, and explain results


Summary of Visibility Benefits of Annex Milestones versus Command & Control with uncertainty Class I areas on Colorado Plateau

Best 20% days: The same or better in all 16 GCVTC Class I Areas Worst 20% days: The same or better in 15 of the 16 GCVTC Class I

Areas (exception is Petrified Forest) Other Class I Areas in the contiguous WRAP Region

Best 20% days: The same or better in all but one Class I Area (exception is Chiricahua Wilderness)

Worst 20% days: The same or better in all Class I Areas Class I Areas in AR, MI, MN, MS, OK, and TX

The same or better on the Best 20 % and Worst 20% Days


Preliminary Results for Proposed Mobile Source Significance Threshold Test Initial evaluation involved turning off only on-road

emissions for the entire modeling domain Evaluating just on-road emissions, the change in

extinction ranges from 3.6% to 8.1% of the Worst Days’ Natural Visibility Condition values at the 16 GCVTC Class I areas on Colorado Plateau

Additional mobile source significance tests


Results for Proposed Road Dust Significance Threshold Test Initial evaluation involved turning off paved and

unpaved road dust emissions for the entire modeling domain

Evaluating all road dust emissions, the change in extinction ranges from 0.8% to 3.1% of the Worst Days’ Natural Visibility Condition values at the 16 GCVTC Class I areas on Colorado Plateau

Regional modeling indicates that road dust emissions are not significant at the initial threshold value


Next steps for technical work products in the upcoming 6 to 8 months Provide additional mobile on-road significance

modeling runs Total mobile (on- & off-road) for the 9 GCVTC states Effect of California mobile emissions Individual urban areas as needed

Provide modeling for Fire Management Scenarios 2018 “all control strategies” modeling run Technical Support Document 2/03 Technical Workshop to hand off TSD (4 days)

technical review workshop report technical oversight committee for the wrap board meeting – july...

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