1. 1 State Implementation Plan (SIP) Modeling for 8-hour Ozone Preliminary 2009 Results For Triangle and Rocky Mount Stakeholders Mike Abraczinskas, NCDAQ Laura Boothe, NCDAQ George Bridgers, NCDAQ Bebhinn Do, NCDAQ July 13, 2005

2. 2 Preface 2008 emissions inventories are being developed by NCDAQ for the Triangle and Rocky Mount nonattainment areas Preliminary 2008 emissions and air quality modeling to be performed by NCDAQ !!! 2009 emissions and air quality modeling results are being presented here today as a surrogate for 2008 !!!

3. 3 Outline Review / Background Typical 2002 and Future 2009 emissions Attainment test – How does it work? Attainment test – Preliminary Results Next steps –Emissions changes anticipated in next set of modeling (2002 & 2008)

4. 4 Background 8-hour ozone standard –If a monitored design value is > 0.08 ppm (84 ppb), that monitor is violating the standard –The design value is defined as: 3-year average of the annual 4 th highest daily maximum 8-hour average

5. 5 NC 8-hr Ozone Nonattainment Areas

6. 6 Ozone Nonattainment Timeline Definitions for Triangle and RMT Areas Effective date = Transportation conformity date = SIP submittal date = Attainment date = Data used to determine attainment = (Modeling) Attainment year = Redesignation base years = Maintenance years = June 15, 2004 June 15, 2005 June 15, 2007 June 15, 2009* 2006-2008 2008 2005 or 2006 TBD * Or as early as possible

7. 7 What if area attains prior to SIP submittal date? Redesignation/Maintenance SIP

8. 8 Redesignation/Maintenance SIP Process Overview Area attains standard (2005 or 2006) –Develop emissions inventory for the year area attains standard –Develop maintenance emissions inventories for at least 10 years beyond redesignation approval Determined through Inter-Agency Consultation Process –Develop interim/maintenance emissions inventories 3 to 5 year increments –Compare maintenance emissions to attaining years emissions Maintenance emissions must be lower than attaining years emissions… If not, control strategies must be developed

9. 9 Redesignation/Maintenance SIP Process Overview Develop draft SIP package –Emissions comparisons –Motor Vehicle Emissions Budgets –Contingency measures Take draft SIP to public hearing –30 day comment period Submit to EPA anytime prior to June 2007 Update plan 8 years after redesignation –Must examine additional 10 years beyond final maintenance year in redesignation package

10. 10 Modeling Application Process Select areas or domains of interest Select representative ozone season/episodes Prepare and refine meteorological simulations Prepare and refine emission model inputs Apply air quality modeling system Performance evaluation of air quality modeling system Prepare current and future year emissions Re-apply air quality modeling system Apply the attainment test May 31st Today

11. 11 Modeling Domains 36 km 12 km

12. 12 Modeling Season / Episode Full Year of 2002 selected for VISTAS modeling –Regional Haze / Fine Particulate: Full Year –Ozone: Late May – End Of August This is the portion of the 2002 ozone season when the majority of ozone exceendances took place.

13. 13 Air Quality Modeling System Meteorological Model Emissions Processor Air Quality Model MM5 SMOKE CMAQ Sparse Matrix Operator Kernel Emissions Community Multiscale Air Quality System Temporally and Spatially Gridded Air Quality Output predictions

14. 14 State Implementation Plan (SIP) Need a SIP submittal to EPA within three years –Attainment Demonstration that details the States plan to bring the area into attainment of the Federal standard –Triangle and RMT areas…must include: Reasonably Available Control Measures (RACM) Reasonable Further Progress (RFP)

15. 15 Requirements RACM Requirements –Applies to all source sectors (point, area, highway mobile & off-road mobile sources) Point Sources referred to as RACT (Reasonably Available Control Technology) –Only what is necessary to attain NAAQS as expeditiously as practicable –NC has already adopted some RACM type rules Open burning ban during ozone events Expanded I/M program Pre-adopted VOC and NOx RACT rules for the 1- hour ozone nonattainment areas

16. 16 2002 Typical and 2009 Emissions Overview Mike Abraczinskas, NCDAQ Environmental Engineer II Note !!! 2008 emissions inventories are being developed by NCDAQ for the Triangle and Rocky Mount nonattainment areas Preliminary 2008 emissions and air quality modeling to be performed by NCDAQ !!! 2009 emissions and air quality modeling results are being presented here today as a surrogate for 2008 !!!

17. 17 Emissions Inventory Definitions ActualActual = the emissions inventory developed to simulate what happened in 2002 TypicalTypical = the emissions inventory developed to characterize the current (2002) emissions… It doesnt include specific events, but rather averages or typical conditions (e.g. EGUs and fires) FutureFuture = the emissions inventory developed to simulate the future (e.g. 2008 for Triangle and Rocky Mount modeling) ***Remember… Actual is used for model performance evaluation only! Typical and Future are used to determine future attainment status.

18. 18 Preliminary 2002 Typical & 2009 Emissions Comparison North Carolina Statewide NOx Emissions

19. 19 Preliminary 2002 Typical & 2009 Emissions Comparison North Carolina Statewide NOx Emissions Triangle Area Includes: Chatham, Durham, Franklin, Granville, Johnston, Orange, Person, Wake

20. 20 Preliminary 2002 Typical & 2009 Emissions Comparison North Carolina Statewide NOx Emissions Rocky Mount Area Includes: Edgecombe and Nash

21. 21 2002 Typical and 2009 Emission Summaries Point Area & Nonroad Mobile Triangle and Rocky Mount nonattainment areas –NOx bar charts

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30. 30 Chatham County 2002 VMT 2002 NOx emissions = 7.1 tpd 2009 VMT 2009 NOx emissions = 5.0 tpd

31. 31 County Durham County 2002 VMT 2009 VMT 2002 NOx emissions = 24.2 tpd 2009 NOx emissions = 14.3 tpd

32. 32 Franklin County 2002 VMT 2009 VMT 2002 NOx emissions = 5.3 tpd 2009 NOx emissions = 3.4 tpd

33. 33 Granville County 2002 VMT 2009 VMT 2002 NOx emissions = 11.8 tpd 2009 NOx emissions = 5.4 tpd

34. 34 Johnston County 2002 VMT 2009 VMT 2002 NOx emissions = 34.8 tpd 2009 NOx emissions = 20.5 tpd

35. 35 Orange County 2002 VMT 2009 VMT 2002 NOx emissions = 21.8 tpd 2009 NOx emissions = 9.9 tpd

36. 36 Person County 2002 VMT 2009 VMT 2002 NOx emissions = 2.9 tpd 2009 NOx emissions = 1.5 tpd

37. 37 Wake County 2002 VMT 2009 VMT 2002 NOx emissions = 71.3 tpd 2009 NOx emissions = 38.6 tpd

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39. 39 Edgdcombe County 2002 VMT 2009 VMT 2002 NOx emissions = 7.0 tpd 2009 NOx emissions = 1.8 tpd

40. 40 Nash County 2002 VMT 2009 VMT 2002 NOx emissions = 19.5 tpd 2009 NOx emissions = 11.2 tpd

41. 41 ONROAD Mobile NOx 2009 minus 2002 (max difference) Reductions only Scale 0 to –0.5 moles/s

42. 42 Triangle* NOx emissions * Triangle Area Includes: Chatham, Durham, Franklin, Granville, Johnston, Orange, Person, Wake

43. 43 Rocky Mount* NOx emissions * Rocky Mount Area Includes: Edgecombe and Nash Counties

44. 44 Air Quality Modeling Results Bebhinn Do, NCDAQ Meteorologist

45. 45 What is a Modeled Attainment Demonstration? Analyses which estimate whether selected emissions reductions will result in ambient concentrations will meet NAAQS An identified set of control measures which will result in the required emissions reductions Use the Modeled Attainment Test to estimate emissions reduction needed to demonstrate attainment

46. 46 What is the Attainment Test ? An exercise in which an air quality model is used to simulate current and future air quality near each monitoring site. Model estimates are used in a relative rather than absolute sense. Future ozone design values are estimated at existing monitoring sites by multiplying a modeled relative reduction factor at locations near each monitor times the observed monitor-specific ozone design value. The resulting projected site-specific future design value is compared to NAAQS. If all such future site-specific design values are 84 ppb, the test is passed.

47. 47 Attainment Test DVF = RRF * DVC DVF = Future Design Value RRF = Relative Reduction Factor DVC = Current Design Value

48. 48 Attainment Test DVF = RRF * DVC RRF is based on modeled data Future modeled values Current modeled values DVC is based on observed data If DVF is 84 ppb, the test is passed.

49. 49 Attainment Test Step 1: Compute a current site-specific design value (DVC) from monitored data Step 2: Use air quality modeling results to estimate a site- specific relative reduction factor (RRF) Step 3: Multiply the relative reduction factor obtained in step 2 times the site-specific design value in step 1… The result is a predicted site-specific future design value (DVF)… If DVF is 84 ppb, the test is passed. DVF = RRF * DVC

50. 50 Attainment Test Step 1: Compute the current design value (DVC) The DVC is calculated for each monitoring site within a nonattainment area. EPA Draft Final Guidance for the 8-hour Ozone standard suggests a few possible methods for calculating the DVC.

51. 51 Method 1 Use the design value corresponds to the period used in the attainment designation. Same steps as determining a design value for designation: –Step 1: Sort all daily 8-hour average maximums in order from highest to lowest into a list for 2001 –Step 2: Repeat Step 1 for the next two consecutive years (2002 & 2003) creating a total of three lists –Step 3: Average the 4 th highest from each list or across the 3-year span

52. 52 Method 2 Use the design value period that straddles the baseline inventory year. Our baseline year is 2002; the corresponding DVC would be the average of the 4 th highest 8- hour ozone concentrations from 2001, 2002, 2003. Results in the same value for Method 1 for our modeling.

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55. 55 Method 3 Average of the three design value period which include the baseline inventory year. Average of the 2000-2002, 2001-2003, 2002-2004 design value. This method represents the baseline concentrations while taking into account the variability in meteorology and emissions. EPA recommended method.

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58. 58 Method 4 Average of the design values for the 5 year period that straddles the baseline inventory year. Average of the 4 th highest values from 2000, 2001, 2002, 2003, & 2004. This method takes into account the variability in meteorology and emissions without giving one year a higher weight than another.

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61. 61 DVC Summary

62. 62 Attainment Test Step 1: Compute a current site-specific design value (DVC) from monitored data Step 2: Use air quality modeling results to estimate a site- specific relative reduction factor (RRF) Step 3: Multiply the relative reduction factor obtained in step 2 times the site-specific design value in step 1… The result is a predicted site-specific future design value (DVF)… If DVF is 84 ppb, the test is passed. DVF = RRF * DVC

63. 63 Relative vs. Absolute Why use model estimates in a relative rather than absolute sense? –The form of the 8-hr standard (4th highest averaged over 3 years) makes it difficult to tell whether or not a modeled exceedance obtained on one or more days selected from a limited sample of days is consistent with meeting the NAAQS –Problems with model performance are reduced (although good model performance remains a prerequisite for use of a model in an attainment demonstration)

64. 64 Attainment Test

65. 65 Attainment Test Step 2 (cont)... Definition of near a monitor –EPA guidance recommends considering an array of values near each monitor –Assume a monitor is at the center of the grid cell in which it is located and that cell is the center of an array of nearby cells –Using a grid with 12 km grid cells, nearby is defined by a 3 x 3 array of cells, with the monitor located in the center cell

66. 66 Attainment Test Step 2 (cont)... Days used in RRF calculation EPA has established cutoff value for model values to be used in the calculation of the RRF The predicted baseline (2002 typical) maximum 8- hour concentrations < 70 ppb are excluded. It is expected that future guidance will use 85 ppb as a cutoff value with the stipulation that 10 days are needed to calculate a RRF. If the monitoring site does not have 10 days above 85 ppb, the cutoff is lowered until 10 days are obtained for the calculation.

67. 67 Attainment Test Step 2 (cont)... Computing the RRF Once the days in the baseline year that meet the cutoff value are identified, the peak value for each grid cell is determined for the day. The maximum of the peak daily values from the 3x3 grid array are then identified. The maximum from the array are averaged for all days identified to determine the Current Mean Peak 8-hour Daily Maximum.

68. 68 Attainment Test Step 2 (cont)... Computing the RRF This is then repeated for the same set of days from the Future year modeling. The maximum averaged value from the array is referred to as the Future Mean Peak 8-hour Daily Maximum. To obtain the RRF the Future Mean Peak 8-hour Daily Maximum is divided by the Current Mean Peak 8-hour Daily Maximum.

69. 69 Example Calculation http://www.epa.gov/scram001/guidance/guide/draft-final-o3.pdf

70. 70 Attainment Test Step 1: Compute a current site-specific design value (DVC) from monitored data Step 2: Use air quality modeling results to estimate a site- specific relative reduction factor (RRF) Step 3: Multiply the relative reduction factor obtained in step 2 times the site-specific design value in step 1… The result is a predicted site-specific future design value (DVF)… If DVF is 84 ppb, the test is passed. DVF = RRF * DVC

71. 71 Attainment Test Step 3: Compute the future design value (DVF) DVF = RRF * DVC Example: DVF x(09) = Mean projected peak 8-hr daily max "near" monitor "x" DVC x X Based on observed O3 data 2002 Meteorology 2002 Emissions, processed with 2002 Meteorology 2002 Meteorology 2008 Emissions, processed with 2002 Meteorology

72. 72 Preliminary Results

73. 73 Attainment Test DVF = RRF * DVC How sure are we that were going to attain? Test the following: 1.Use the various DVC calculation methods 2001-2003 DVC, Weighted Average, Average 2.Use both minimum thresholds (>70 ppb, >85ppb ) for excluding certain modeled days

74. 74 Just a reminder... This is based on preliminary 2009 modeling DVC Used: –01-03: The 2001 – 2003 design value. –Weighted Average: (DV(00–02) + DV(01-03) + DV(02-04))/3 OR (4h(00)+ 2*4h(01)+ 3*4h(02)+ 2*4h(03)+ 4h(04))/9 –Average (4h(00)+ 4h(01)+ 4h(02)+ 4h(03)+ 4h(04))/5

75. 75 Preliminary Results – Triangle & Rocky Mount

76. 76 Preliminary Results – Triangle & Rocky Mount

77. 77 The different methods can be used in conjunction with the test… OR Some could be used as supplemental analyses in a Weight Of Evidence determination… Attainment Test

78. 78 Emission Inventory Improvements Mike Abraczinskas, NCDAQ Environmental Engineer II

79. 79 2008 vs. Preliminary 2009 Point Source Inventory Improvements Initial 2009 Electric Generating Unit (EGU) emissions were developed using assumptions in the Integrated Planning Model (IPM). –Those assumptions at facilities subject to the NC Clean Smokestacks Act (CSA) were not consistent with the CSA compliance plan. Changes upcoming –Final 2008 run will include unit specific emissions as specified in the June 1, 2005 NC CSA Compliance Plan submitted by Progress Energy and Duke Energy –Correction of Congentrix facility emissions in Edgecombe County

80. 80 2002 Typical and 2008 Area & Nonroad Inventory Improvements Area & Nonroad sources –New data acquired from Raleigh-Durham International Airport Growth assumptions changes –Residential wood combustion emissions over- estimated

81. 81 2002 Typical and 2008 Onroad Mobile Source Inventory Improvements 2002 VMT updated to reflect latest NCDOT data used in recent transportation conformity analysis 2008 VMT is generally lower than 2009

82. 82 Next Steps Laura Boothe, NCDAQ Attainment Planning Chief

83. 83 Next Steps Based on EPAs expected final modeling guidance: –The preliminary 2009 results show that the Triangle and Rocky Mount areas will pass the attainment test Given the 2009 results are well below the standard, the 2008 results will likely show attainment Caveats: –2008 vs. 2009 –Several emissions improvements –Cannot predict exactly how the DVFs will change

84. 84 Schedule Emission Inventory improvements ~June/July 2005 New/refined 2002 emissions and air quality modeling ~Aug/Sept 2005 Preliminary 2008 emissions and air quality modeling ~ Aug/Sept 2005 Until then… Discussion will continue on: –RACT, RACM –Motor Vehicle Emission Budgets (MVEBs) –Follow latest updates to EPA Modeling Guidance After 2002 & 2008 emissions & air quality modeling is complete… –Hold another Stakeholder Meeting ~Oct 2005 Summarize emissions changes Present latest attainment test results Have more detailed discussions on RACT, RACM, MVEBs

85. 85 Motor Vehicle Emission Budgets (MVEBs) Estimates of the 2008 mobile source emissions from attainment modeling exercise –Can be estimated using MOBILE6 outside of SMOKE modeling framework Will have opportunity to use new/improved input data –As long as its not significantly different than input data in attainment modeling

86. 86 Motor Vehicle Emission Budgets (MVEBs) We have options on how to set MVEBs Area-wide vs. Sub-Area

87. 87 Area-Wide MVEBs Advantages –Budgets can be shared (if the SIP language allows this) Disadvantages –MPOs/RPOs must collectively make a conformity determination –One MPO/RPO in the non-attainment area (NA) lapses, everyone lapses (assuming more than one MPO/RPO in the NA area)

88. 88 Sub-Area MVEBs Advantages –Once conformity is established for entire NA area….. Conformity determinations can be made for specific MPOs/RPOs (without impacting the entire NA area) If one MPO/RPO within the NA lapses it does not impact remaining areas until their next conformity determination

89. 89 Sub-Area (continued) Disadvantages –Budgets cannot be shared

90. 90 MVEBs Need from transportation partners: –New/improved data, if available ~Fall 2005 –Discussion on how to set MVEBs ~NOW – Feb 2006 If Area-wide budgets… –Need unanimous agreement with strong justification as to why by February 2006 Otherwise, county by county (sub-area budgets)

91. 91 Contributors Pat Brewer, VISTAS Greg Stella, Alpine Geophysics Cyndi Loomis, Alpine Geophysics Don Olerud, Baron Advanced Meteorological Systems Bill Barnard, MACTEC Ed Sabo, MACTEC Kristen Theising, PECHAN Ralph Morris, ENVIRON Gail Tonneson, University of California-Riverside Dennis McNally, Alpine Geophysics Jim Boylan, Georgia Environmental Protection Department Sheila Holman, NCDAQ Bebhinn Do, NCDAQ Nick Witcraft, NCDAQ Phyllis Jones, NCDAQ Vicki Chandler, NCDAQ Pat Bello, NCDAQ Bob Wooten, NCDAQ Matt Mahler, NCDAQ Janice Godfrey, NCDAQ Ming Xie, NCDAQ Mildred Mitchell, NCDAQ VISTAS Stakeholders

92. 92 Questions/Comments http://daq.state.nc.us/ Laura Boothe, Chief of Attainment Planning 919-733-1488 Laura.Boothe@ncmail.net Mike Abraczinskas, Environmental Engineer II 919-715-3743 Michael.Abraczinskas@ncmail.net Bebhinn Do, Meteorologist 919-715-0921 Bebhinn.Do@ncmail.net

93. 93 Thank You!