1 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Western Regional Air Partnership (WRAP) Projection of Visibility Changes and Modeling Sensitivity Analysis Presented by: Ralph Morris WRAP Regional Modeling Center (RMC ) University of California/ENVIRON Corp. Presented at: RPO National Workgroup Meeting November 4-6, 2003 St. Louis, Missouri

2 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt WRAP Visibility Objectives §309 SIP/TIP due 2004 – 9 “Grand Canyon” states may opt-in (AZ, CA, CO, ID, NV, NM, UT, and WY). – Focus on 16 Class I Areas on the Colorado Plateau §308 SIP/TIP due 2007 – visibility baseline – 2018 end of first planning period – Show progress toward natural visibility conditions by 2064

3 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Section 309 SIP/TIP Modeling Requirements Demonstrate that SO 2 Annex Milestone control strategy is better than BART with Uncertainty Estimate visibility improvements in 2018 due to §309 Scenarios 1 & 2 Analyze “significance” of Mobile Source and Road Dust at 16 Class I Areas Evaluate PM/NOx point source controls Evaluate alternative fire management practices

4 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt WRAP CMAQ and REMSAD Modeling Domains

5 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Projecting Future-Year Visibility Follow EPA draft guidance for projecting future- year visibility (EPA, 2001a,b,c) Use model in a relative fashion to scale the current (1996 or l) observed visibility for the Best 20% and Worst 20% days based on the ratio of the 2018 to 1996 modeling results – Relative Reductions Factors (RRFs) – Class I Area specific (map IMPROVE data) – Specific for each component of light extinction (SO4, NO3, EC, OC, Soil, and CM)

6 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Mapping of IMPROVE Data to Class I Areas

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8 Projecting Future-Year Visibility Deviations from EPA Guidance for §309 SIP – Baseline for W20%/B20%? 1996 Modeling Baseline: – Use 1996 W20%/B20% obs days to define RRF 2018 projection factors – Use two observed visibility baselines » W20%/B20% days from 1996 » W20%/B20% days from latest 5-yrs ( )

9 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Projecting Future-Year Visibility Deviations from EPA Guidance for §309 SIP – No wind blown fugitive dust in inventory – Major component of Soil and CM – Some observed Soil and CM impacts likely sub-grid scale (< 36 km) Model estimated RRFs for Soil and CM are in error Set RRFs for Soil and CM to unity – RRF(Soil) = RRF(CM) = 1.0 – Assumes 2018 Soil and CM identical to current year

10 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt 2018 §309 Control Scenarios 1 & 2 Area sources, base case Road dust base case Off-Road, base case On-Road base case 1996 Biogenic base case “Typical year” Wildfires base case Point source control case (SO 2 Annex Milestones combined with Pollution Prevention) Mexico inventory (area/point) Agricultural and Rx fires: – Scenario 1: Base Smoke Management (BSM) – Scenario 2: Optimal Smoke Management (OSM)

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12 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt 2018 §309 Control Scenarios 1 & 2

13 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Calculation of 2018 Visibility Goals Glide Path Slope to Natural Conditions (NCs) in Observed Baseline Visibility Conditions (Anchors Glide Path Slope) – Worst 20% Days: Progress toward Natural Visibility Conditions in 2064 with Planning Periods ending at 2018, 2028, 2038, 2048, 2058, and 2064 – Best 20% Days: No Degradation in Visibility Glide Path Slope Values assumes linear progress from 2004 observed visibility to NCs in 2064

14 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Preliminary Glide Path Slope Values to NCs Use most current 5-yrs of observed visibility to anchor Glide Path in 2004 – IMPROVE data currently most recent Map Observed Visibility Conditions from IMPROVE Monitors to Nearby Class I Areas Use current EPA draft guidance for natural conditions (NC) for worst days (EPA, 2001) – Needs to be evaluated for appropriateness Sea salt, wind blown dust, wildfires, Asian dust, Saharan dust, geogenic, biogenic

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21 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Mobile Source Significance Change in extinction due to Mobile Sources over the EPA Natural Conditions (Worst 20% Days) Applied to 13 urban areas and California to estimate “significance” at 16 Class I Areas on Colorado Plateau No On-Road and Off-Road Mobile Source Emissions (“Zero-Out”) modeling priorities: – 9 Grand Canyon (GC) States (Cumulative) – California – Phoenix, Arizona (Maricopa County) – Las Vegas, Nevada (Clark County)

22 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Summary of 2018 Anthropogenic Emissions in 9 Grand Canyon (GC) States

23 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Comments on 2018 Emissions in 9 GC States 47% NO X due to “Mobile Sources” – 64% Off-Road vs. 36% On-Road 21% SO 2 due to “Mobile Sources” – Almost all (97%) due to Off-Road Sources – Off-Road gas engines use low sulfur gasoline – Upcoming Off-Road Rules for some Off-Road equipment expected before 2018 not accounted for (e.g., S reduction) Mobile PM 2.5 is 12% of total but consists of EC & OC with high light extinction efficiencies New EPA NONROAD model results in substantial reductions in emissions over old NONROAD

24 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt What is a significant visibility impact? A 2 deciview (dv) or 20% change in extinction is believed to be a perceptible change PSD Class I Area visibility AQRV analysis uses a 10 % change in extinction over natural conditions threshold for cumulative impacts Definition of natural conditions a point of controversy – e.g., how to treat weather interference Use two visibility backgrounds – EPA natural conditions – 2018 Base Case conditions

25 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Cumulative Mobile Source Significance Test 9 GC States, EPA Natural Conditions, & 2018 WRAP Base Case

26 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Estimate On-Road & Off-Road Contributions 9 GC States for Petrified Forest, Capitol Reef, and Grand Canyon

27 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Road Dust Significance Results Road Dust mainly in Soil and CM components so cannot use scaled modeling results – Currently Road Dust is 20% of PM 10 emissions in 9 GC States (w/o wind blown dust) – Missing wind blown dust – Some of Road Dust impacts likely subgrid-scale Use Absolute Modeling Results – Can’t use RRFs as RRF(CM)=RRF(Soil)=1.0 Cumulative impact range from 0.80% to 3.13%

28 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Road Dust Emissions Significance Test Using W20 Absolute Model Results (No RRFs)

29 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Stationary Source Sensitivity NOx and/or PM 10 emission changes on major stationary sources (> 100 TPY) – 50% reduction in NOx emissions – 50% reduction in PM10 emissions – 25% increase in NOx & PM10 emissions Purpose: – § 309 must analyze stationary source NOx/PM controls evaluate NOx/PM control strategies assess impacts of such controls on visibility evaluate the need for NOx/PM control program

30 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Stationary Source Sensitivity -- Conclusions Stationary source PM emissions contribute approximately 2% on average to visibility impairment Stationary source NOx emissions contribute: – 2-5% to impairment on average at Class I areas on the Colorado Plateau larger contributions on some of the haziest days – ~20% at some Class I areas in the Pacific Northwest and California

31 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Stationary Source NOx Emissions > 100 TPY Utility Boilers Utility ICEs Industrial ICEs Industrial Processes Industrial Boilers 91% of the emissions > 100 tpy

32 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Stationary Source NOx Emissions > 100 TPY

33 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt 50% NOx Control on Ammonium Nitrate

34 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt 1996 Annual (NH 4 ) 2 NO IMPROVE Sites

35 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt % Light Extinction due to Nitrate W20%

36 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Stationary Source PM 10 Emissions > 100 TPY Utility Boilers Industrial Boilers Mineral Products Chemical Manufacturing Primary Metal Production Industrial Processes 78% of the emissions > 100 tpy

37 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt Stationary Source PM 10 Emissions > 100 TPY

38 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt 50% PM10 Control on PM10

39 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt 1996 Annual PM IMPROVE Sites

40 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt % Annual Extinction due to Coarse Matter

41 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt § 309 Stationary Source NOx/PM Analysis § 309 Stationary Source PM/NOx Report – available at: – Starting point for multi-year process – Determination of BART eligible NOx/PM sources – Identification of NOx/PM control options – Assessment of visibility improvements due to alternative stationary source NOx/PM controls progress toward 2064 natural conditions goal better modeling needed – nitrate performance issues – PM performance issues

42 Projects:/WRAP_RMC/Presents/ADEQ_Feb ppt EPA Visibility Projection Procedure Calculated only at Class I Areas – Implies model spatial and temperal accuracy – Ignores visibility/PM changes over most of domain – Model vs observed W20%/B20% days Need for Additional Vvisibility Metrics – Spatial plots of visibility “Improvements” – Other days than observed W20%/B20% – Other?