Table 6.4.3 4 Summary of Additional Corroborative Analyses Test Name 2007 Future Design Value ( ppb) Original Attainment Test 87 Higher DVC 00 02 & 01 03 86 DVC 01 03 84 DVC 00 03 84 obs < 70 original test 86 obs < 70 w/ DVC 01 03 83 +/ 10 original test 86 +/ 10 DVC 01 03 83 AVERAGE 84 MEDIAN 84 Triad EAC Ozone Action Plan Page 63 March 31, 2004 It is important to note that these analyses and their results are based on EPA's Modeling Guidance. The elements of the analyses that are not explicitly covered in the Draft 8 hour Ozone Guidance are based on like principles and should be given similar credibility.

6.4.4 Additional Corroborative Analyses  Analysis of Other Source Regions Introduction The intent of analyzing other source regions is to show how frequently and to what degree particular areas impact Cooleemee on days when ozone concentrations were high. It is the experience of NCDAQ meteorologists that Cooleemee is often affected by pollution originating from either the Triad or Charlotte metropolitan areas. On days when the prevailing wind flow is from the south and southwest, the Charlotte region would be expected to have the greatest impact on Cooleemee. On days when the wind flow is more northerly or northeasterly, the Triad region would be expected to have a greater impact on Cooleemee. There are days when the wind flow is such that neither the Triad nor Charlotte regions wo uld have the most significant impact on Cooleemee, such as moderate easterly or westerly flow. NCDAQ hypothesizes that analysis of these other source regions will show that the Charlotte region was the predominant area of influence on Cooleemee. As such, emissions reductions that will take place in the Charlotte region would lead to reductions in ozone concentrations ( future design values) at Cooleemee.

Methodology An examination of back trajectories for five years ( 1999 2003) was made at the Cooleemee ozone monitor site in Davie County, North Carolina. Specifically, days when the observed 8 hr average ozone concentrations was greater than 84 ppb were analyzed to determine the probable source regions for transported ozone and its precursors. Back trajectories were created using the National Oceanic and Atmospheric Administration Air Resource Laboratory ( NOAA ARL) HYbrid Single Particle Lagrangian Integrated Trajectory ( HYSPLIT; Draxler and Rolph, 2003) model version 4. The 80 km EDAS data was used as the data set for the trajectory analysis.

Using the criteria that the observed 8 hr average ozone concentrations was greater than 84 ppb, a total of 78 days from 1999 through 2003 met the criteria for the Cooleemee monitor. Of those 78 days, three days were eliminated from the back trajectory analysis due to missing data in the EDAS data set. Individual back trajectories were run for each of the remaining 75 days using the HYSPLIT model. The first analysis of these trajectories used visual inspection to determine the most likely source region for the pollution measured at the Cooleemee site for each day. The possible source region( s) could be Charlotte, the Triad, some other region, or any combination of the three. The second analysis separated the trajectories based on observed ozone concentration at the Cooleemee site in order to relate the observed concentration of ozone to the source region.

Results From the analysis based on source region, it was determined that the Charlotte region was the most likely source on 36 of the days, the Triad region on 15 of the days, other region on 11 of the days, and a combination of the Charlotte and Triad regions on 10 of the days ( Table 6.4.4 1). Triad EAC Ozone Action Plan Page 64 March 31, 2004 There were also three days when Charlotte and other or Triad and other were determined to be the source regions. Figure 6.4.4 1 shows the composite of the trajectories at the 10 meter level of the 36 days when the Charlotte region was determined to be the predominant source region. There is a clear distinction of southerly and westerly flow through the Charlotte region.

Date Charlotte Triad Other Date Charlotte Triad Other 5/ 21/ 1999 87 X X 5/ 19/ 2001 87 X 5/ 29/ 1999 86 X 6/ 19/ 2001 87 X X 5/ 30/ 1999 85 X 6/ 20/ 2001 94 X X 6/ 9/ 1999 110 X 6/ 21/ 2001 102 X 6/ 10/ 1999 100 X X 7/ 17/ 2001 90 X 7/ 6/ 1999 90 X X 8/ 3/ 2001 86 X 7/ 16/ 1999 86 X X 8/ 9/ 2001 98 X 7/ 28/ 1999 88 X 8/ 23/ 2001 104 X 7/ 31/ 1999 87 X 8/ 25/ 2001 85 X 8/ 4/ 1999 91 X 5/ 24/ 2002 86 X 8/ 5/ 1999 86 X X 6/ 4/ 2002 100 X 8/ 6/ 1999 91 X 6/ 5/ 2002 96 N/ A N/ A N/ A 8/ 7/ 1999 110 X X 6/ 10/ 2002 91 X X 8/ 10/ 1999 87 X X 6/ 11/ 2002 112 X 8/ 11/ 1999 90 X 6/ 13/ 2002 93 X 8/ 12/ 1999 91 X 7/ 2/ 2002 92 X X 8/ 13/ 1999 138 X 7/ 8/ 2002 88 X 8/ 14/ 1999 89 X 7/ 9/ 2002 94 X 8/ 17/ 1999 87 X 7/ 16/ 2002 86 X 8/ 18/ 1999 97 X 7/ 17/ 2002 95 X 8/ 19/ 1999 95 X 8/ 1/ 2002 90 X 8/ 28/ 1999 94 X 8/ 2/ 2002 96 X 9/ 8/ 1999 91 X 8/ 9/ 2002 90 X 9/ 13/ 1999 88 X X 8/ 10/ 2002 88 X 5/ 19/ 2000 89 X 8/ 11/ 2002 98 X 6/ 2/ 2000 98 N/ A N/ A N/ A 8/ 12/ 2002 97 X X 6/ 9/ 2000 89 X 8/ 13/ 2002 99 X 6/ 10/ 2000 93 X 8/ 21/ 2002 85 X 6/ 11/ 2000 93 X 8/ 22/ 2002 90 X 6/ 12/ 2000 95 X 8/ 23/ 2002 98 X 6/ 13/ 2000 94 X 9/ 5/ 2002 89 X 6/ 24/ 2000 88 N/ A N/ A N/ A 6/ 10/ 2003 89 X 7/ 2/ 2000 93 X 6/ 24/ 2003 89 X 7/ 8/ 2000 88 X 6/ 25/ 2003 106 X 7/ 10/ 2000 96 X 6/ 26/ 2003 100 X 7/ 18/ 2000 98 X Total Days 23 12 4 7/ 19/ 2000 92 X 7/ 28/ 2000 89 X Charlotte = 48 8/ 7/ 2000 88 X Triad = 26 8/ 17/ 2000 86 X Other = 14 9/ 14/ 2000 85 X CLT& Triad= 10 5/ 4/ 2001 87 X 5/ 15/ 2001 87 X Charlotte only = 36 Total Days 25 14 10 Triad only = 15 Table 6.4.4 1. Trajectory source regions for days when the observed 8 hr ozone concentration at Cooleemee was 85 ppb or greater from 1999 through 2003. An " X" indicates that the region was determined to be potential source region for ozone and precursor pollutants on that day. " N/ A" indicates that the EDAS data needed to run the trajectory for that day was not available, and therefore no trajectory was available for analysis. Cooleemee Trajectory Analysis Results Triad EAC Ozone Action Plan Page 65 March 31, 2004 Figure 6.4.4 2 shows a similar composite for those days when the Triad region was determined to be the predominant source region. On these days, there is a clear distinction of northerly and northeasterly flow through the Triad region. Figure 6.4.4 3 shows the composites for those days when both the Charlotte and Triad regions were determined to impact the Cooleemee monitor. There appears to be a favored southwest flow at the 10 meter level, while at 300 and 1000 meters ( not shown), the southwest flow is not as evident. The predominance of southwest flow at the Figure 6.4.4 1. Composite image of back trajectories at the 10 meter level for the 36 days ( 1999 2003, 85 ppb or greater) when the Charlotte region was identified as the predominant source region.

Figure 6.4.4 2. Composite image of back trajectories at the 10 meter level for the 15 days ( 1999 2003, 85 ppb or greater) when the Triad region was identified as the predominant source region. Triad EAC Ozone Action Plan Page 66 March 31, 2004 lowest level may be an indicator of the influence of low level NOx sources originating from the Charlotte region and impacting the Cooleemee site.

For those days when neither the Charlotte nor the Triad regions were determined to impact the Cooleemee site, the wind flow is generally westerly to northwesterly, although on several days there is an obvious easterly component to the flow. In these cases, influence from the Charlotte and Triad regions on Cooleemee would be minimal, but could still play some minor influence on local pollution concentrations near the monitor.

The second analysis that was performed was a separation of the trajectories based on observed ozone concentration. Specifically, four separate bins were created: 85 87 ppb, 88 90 ppb, 91 95, and above 95 ppb. There were 19 days in each of the bins except for the 91 95 ppb bin, which only contained 18 days. While in none of the bins is there an absence of influence from either the Charlotte or the Triad regions, there does appear to be a predominant southwest flow through the Charlotte region in both the 85 87 ppb bin and the above 95 ppb bin ( Figures 6.4.4 4 and 6.4.4 5, respectively), especially at the 10 meter level for the above 95 ppb bin. The latter is significant, since it suggests that on those days when the ozone concentration at Cooleemee was highest the main contributor of ozone and precursor pollutants is the Charlotte region. For the 88 90 ppb and 91 95 ppb bins ( not shown) there appears to be a greater split in the trajectories between the Charlotte and Triad regions than the other bins, suggesting there is not a favored wind flow direction for ozone concentrations in those ranges. Figure 6.4.4 3. Composite image of back trajectories at the 10 meter level for the 11 days ( 1999 2003, 85 ppb or greater) when both the Charlotte and Triad regions were identified as the predominant source regions. Triad EAC Ozone Action Plan Page 67 March 31, 2004 Figure 6.4.4 4. Composite image of back trajectories at the 10 meter level for the 19 days ( 1999 2003) when the observed 8 hr ozone concentration at the Cooleemee monitor site in Davie County was 85 to 87 ppb.

Figure 6.4.4 5. Composite image of back trajectories at the 10 meter level for the 19 days ( 1999 2003) when the observed 8 hr ozone concentration at the Cooleemee monitor site in Davie County was greater than 95 ppb. Triad EAC Ozone Action Plan Page 68 March 31, 2004 Conclusions drawn from Analysis of other Source Regions The above analysis suggests that the Cooleemee monitor is influenced more often by transported ozone and precursor pollutants from the Charlotte region ( 36 of 75 days, 47%) as opposed to the Triad region ( 15 of 75 days, 20%). Also, an analysis of back trajectories based on observed ozone concentration indicates that on those days when the ozone concentration at Cooleemee is greater than 95 ppb, the predominant region of influence is also the Charlotte region. Together these analyses suggest that the majority of time the Cooleemee monitor may be more representative of pollution originating from the Charlotte region rather than the Triad region.

The result of this conclusion is that DAQ expects local pollution control measures that will be implemented in the Charlotte region, which to date have not been included in the current modeling, will lead to larger reductions of pollution in the Triad, and specifically at Cooleemee. Given that well over 50% of the days in the last five years that Cooleemee exceeded the ozone standard a region other than the Triad was the predominant region of influence, emissions controls that will take place outside of the Triad will no doubt have a significant impact on reducing pollution at Cooleemee.

6.4.5 Final Modeling Inventory Changes With the update to the 2007 modeling inventory a number of emission reductions take place. The Statewide point source emissions inventory decreases from the previous version. Included in these point source decreases is 2 tons per day of NOx from RJ Reynolds fuel switching proposed as a local control and over 7 tons per day of NOx reduction from the Duke Energy Marshall facility putting on controls ahead of schedule.

The mobile source updates results in approximately 100 tons per day NOx emissions decreases across the State. Additionally, applying the open burning ban will result in some NOx decreases, the amount of which will be dependent on the rule effectiveness and rule penetration settled upon.

NCDAQ is also working with the Charlotte area and Duke Energy to see if any other emission reductions from downwind of the Triad area are possible.

These additional reductions of NOx emissions in and around the Triad area are expected to bring the Cooleemee monitor into attainment in the final modeling analysis.

6.4.6 Additional Technical Analyses  Conclusions When looking at additional technical analyses for the Cooleemee monitor in the Triad EAC area, NCDAQ believes that there is substantial evidence that this monitor will attain the standard in 2007.

The air quality modeling metrics suggested by EPA demonstrates very large relative reductions ( 90%); a percentage much larger than what EPA recommends to demonstrate future attainment. It has been demonstrated that the current design value used in the attainment test has an impact Triad EAC Ozone Action Plan Page 69 March 31, 2004 on if a monitor is expected to attain. NCDAQ believes that the model may be less responsive to emission reductions than reality. If this is the case, then using the most current design value may be more appropriate.

Back trajectory analysis shows a large impact from the Charlotte region. As NCDAQ and Charlotte begin to address this regions 8 hour ozone problem, the Cooleemee monitor will benefit from the resultant decreases in ozone. To the extent possible, emission reductions expected in the Charlotte area will be included in the final modeling that the State submits in December 2004. Triad EAC Ozone Action Plan Page 70 March 31, 2004 References 1. U. S. EPA. National Ambient Air Quality Standards. http:// www. epa. gov/ airs/ criteria. html.

2. McConnell et al. 2002. Asthma in exercising children exposed to ozone: a cohort study. Lancet 359: 386 391.

3. U. S. EPA. " Smog   Who Does It Hurt? What You Need to Know about Ozone and Your Health" http:// www. epa. gov/ airnow/ health/ index. html.

4. Draxler, R. R. and Rolph, G. D., 2003. HYSPLIT ( HYbrid Single Particle Lagrangian Integrated Trajectory) Model access via NOAA ARL READY Website ( http:// www. arl. noaa. gov/ ready/ hysplit4. html). NOAA Air Resources Laboratory, Silver Spring, MD. Triad EAC Ozone Action Plan Page 71 March 31, 2004 7 Anticipated Resource Constraints The resource constraint of most concern is the funding needed to implement some of the local control measures. NCDAQ and the local EAC areas are both looking for grant opportunities to help fund EAC initiatives. Triad EAC Ozone Action Plan Page 72 March 31, 2004 APPENDIX A Stationary Point Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Alamance 0.68 0.66 1.60 0.07 0.76 1.03 Alexander 0.03 0.04 1.38 0.02 0.00 1.66 Alleghany 0.00 0.01 0.03 Anson 0.13 0.46 0.38 0.00 0.00 0.00 Ashe 0.23 0.16 0.34 0.03 0.01 1.23 Avery 0.00 0.01 0.00 Beaufort 0.04 0.20 0.30 1.48 2.48 0.34 Bertie 0.69 0.36 0.57 0.18 0.27 1.04 Bladen 0.40 1.19 0.49 0.23 2.33 0.58 Brunswick 14.55 6.64 3.87 4.78 9.81 2.79 Buncombe 1.25 53.32 3.60 13.78 13.79 3.10 Burke 2.55 0.84 5.18 7.87 0.61 13.73 Cabarrus 0.82 3.03 4.06 0.18 2.10 3.60 Caldwell 1.35 1.19 21.88 0.51 0.16 28.09 Camden 0.00 0.00 0.00 Carteret 0.15 0.22 0.30 0.01 0.11 0.00 Caswell Catawba 4.16 96.23 18.81 13.14 51.84 20.46 Chatham 4.51 21.19 2.21 7.90 4.72 2.16 Cherokee 0.02 0.02 0.22 Chowan 0.03 0.21 0.37 0.03 0.15 0.01 Clay Cleveland 0.82 1.70 1.04 0.80 4.46 1.62 Columbus 20.82 15.41 6.93 15.75 9.05 2.53 Craven 4.94 4.21 3.73 4.54 4.94 1.85 Cumberland 1.22 3.16 4.08 0.51 3.76 6.86 Currituck 0.08 0.01 0.00 Dare 0.05 0.19 0.01 0.01 0.34 0.00 Davidson 3.31 12.16 15.05 3.02 6.34 20.47 Davie 0.17 0.20 1.98 0.09 0.04 3.79 Duplin 0.24 1.10 0.14 1.11 2.41 0.02 Durham 1.00 1.58 1.19 0.30 1.03 5.73 Edgecombe 0.49 5.95 0.90 0.43 7.29 0.02 Forsyth 2.09 6.15 9.76 1.96 6.78 19.96 Franklin 0.28 0.21 1.71 0.01 0.13 0.12 Gaston 3.67 86.48 5.40 21.44 38.21 7.51 Gates 0.08 0.03 0.10 Graham 0.09 0.08 1.29 0.02 0.02 1.38 Granville 0.34 0.36 1.79 0.37 0.13 1.92 Greene 0.00 0.07 0.00 Triad EAC Ozone Action Plan Page 73 March 31, 2004 Stationary Point Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Guilford 1.59 1.83 18.13 0.17 0.88 39.44 Halifax 6.22 10.72 1.71 17.11 12.80 0.41 Harnett 0.20 0.33 1.12 0.23 0.63 0.62 Haywood 7.85 12.48 5.00 9.26 16.05 2.44 Henderson 0.25 0.31 3.79 0.03 0.43 4.53 Hertford 1.33 0.47 1.13 0.02 0.17 0.24 Hoke 0.08 0.25 0.40 34.24 1.00 10.35 Hyde 0.00 0.04 0.00 Iredell 3.58 9.98 20.42 3.63 11.15 4.37 Jackson 0.60 0.52 0.38 0.00 0.05 0.00 Johnston 0.80 0.46 1.80 0.02 0.15 2.46 Jones Lee 1.37 0.42 1.27 1.14 0.28 0.75 Lenoir 0.63 2.27 1.30 0.14 3.10 0.23 Lincoln 0.76 5.82 2.73 8.90 14.26 2.18 McDowell 2.12 1.04 3.87 0.78 0.71 1.33 Macon 0.11 0.08 0.05 Madison 0.02 0.07 0.00 Martin 10.72 10.38 3.24 31.74 9.97 3.18 Mecklenburg 5.49 2.30 11.99 3.32 3.73 23.26 Mitchell 0.41 0.50 2.49 0.13 0.02 2.09 Montgomery 0.24 0.32 1.99 0.05 0.01 0.02 Moore 0.17 0.14 2.29 0.02 0.00 1.74 Nash 9.02 0.97 2.67 0.50 1.06 0.56 NewHanover 35.65 31.96 6.52 46.31 49.30 6.49 Northampton 1.10 0.30 0.86 0.14 0.30 0.10 Onslow 0.34 1.77 0.16 0.09 1.22 0.02 Orange 2.86 1.80 0.37 3.37 0.78 0.01 Pamlico Pasquotank 0.10 0.07 0.07 0.01 0.02 0.03 Pender 0.00 0.00 0.05 0.02 0.03 0.01 Perquimans Person 5.79 205.34 1.36 13.83 32.70 1.22 Pitt 1.06 0.88 1.95 0.37 0.75 1.11 Polk 0.02 0.03 0.00 Randolph 0.53 0.38 4.01 0.02 0.07 2.33 Richmond 0.33 0.26 0.17 323.38 11.45 10.71 Robeson 0.92 17.43 1.12 1.64 13.56 2.28 Rockingham 5.60 34.09 16.65 17.02 16.47 8.01 Rowan 2.28 37.52 8.27 15.19 19.17 11.65 Rutherford 3.24 49.60 2.56 4.66 13.67 3.45 Sampson 0.24 0.23 0.22 Scotland 0.38 6.14 3.60 0.57 8.50 7.33 Triad EAC Ozone Action Plan Page 74 March 31, 2004 Stationary Point Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Stanly 26.81 1.15 1.79 17.59 1.36 1.94 Stokes 8.15 324.10 1.01 5.16 22.79 0.62 Surry 3.28 1.09 6.10 6.10 1.06 4.12 Swain 0.00 0.00 0.12 Transylvania 0.21 5.00 2.83 0.25 7.01 2.55 Tyrrell Union 0.81 0.68 1.81 0.03 0.17 2.54 Vance 0.34 1.52 1.16 0.04 1.45 0.00 Wake 1.59 1.49 4.24 0.27 0.94 10.08 Warren 0.18 0.08 0.07 Washington 0.00 0.00 0.00 0.00 0.01 0.00 Watauga 0.17 0.18 0.13 0.02 0.05 0.00 Wayne 5.08 19.84 3.38 24.50 27.43 1.85 Wilkes 1.88 0.97 5.69 3.68 0.83 6.11 Wilson 0.51 1.48 3.74 0.22 2.51 1.99 Yadkin 0.01 0.03 0.26 0.00 0.00 0.03 Yancey Stationary Area Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Alamance 6.21 0.47 5.78 6.65 0.50 6.17 Alexander 3.26 0.20 2.96 3.42 0.21 2.93 Alleghany 1.00 0.08 0.79 1.03 0.08 0.81 Anson 3.83 0.16 1.40 4.14 0.17 1.47 Ashe 2.29 0.17 1.42 2.36 0.17 1.50 Avery 1.61 0.12 0.85 1.66 0.13 0.90 Beaufort 22.68 0.30 5.75 25.28 0.31 5.93 Bertie 6.46 0.16 3.25 7.09 0.17 3.20 Bladen 5.37 0.25 3.08 5.79 0.25 3.13 Brunswick 5.25 0.39 3.12 5.47 0.40 3.26 Buncombe 5.74 0.55 8.11 5.91 0.58 8.66 Burke 4.02 0.32 3.48 4.15 0.33 3.64 Cabarrus 5.81 0.38 5.88 6.26 0.41 6.52 Caldwell 3.19 0.25 3.91 3.32 0.25 4.05 Camden 7.54 0.05 1.35 8.43 0.05 1.40 Carteret 5.22 0.20 2.96 5.67 0.20 3.10 Caswell 3.96 0.18 1.69 4.24 0.19 1.71 Catawba 7.04 0.43 11.22 7.48 0.44 11.37 Chatham 4.82 0.34 2.46 5.18 0.36 2.58 Cherokee 2.29 0.19 1.15 2.35 0.20 1.19 Chowan 2.70 0.09 1.61 2.96 0.09 1.65 Triad EAC Ozone Action Plan Page 75 March 31, 2004 Stationary Area Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Clay 0.83 0.08 0.46 0.85 0.08 0.51 Cleveland 8.89 0.43 4.45 9.53 0.45 4.70 Columbus 10.62 0.41 5.37 11.52 0.42 5.36 Craven 6.34 0.28 4.92 6.87 0.29 5.06 Cumberland 6.32 0.51 11.54 6.76 0.54 12.12 Currituck 8.37 0.14 1.61 9.27 0.14 1.71 Dare 0.86 0.08 1.21 0.89 0.08 1.30 Davidson 9.36 0.65 7.74 9.81 0.67 7.96 Davie 4.37 0.19 1.76 4.69 0.20 1.87 Duplin 17.79 0.37 5.91 19.65 0.38 5.95 Durham 2.25 0.35 7.67 2.42 0.39 8.18 Edgecombe 4.60 0.25 5.60 4.96 0.26 5.50 Forsyth 3.94 0.40 11.46 4.18 0.44 12.21 Franklin 7.51 0.36 3.18 8.19 0.37 3.25 Gaston 5.05 0.52 6.85 5.35 0.56 7.35 Gates 1.82 0.08 1.14 1.95 0.09 1.12 Graham 0.75 0.06 0.35 0.77 0.06 0.37 Granville 7.05 0.27 3.27 7.65 0.28 3.34 Greene 5.83 0.15 2.95 6.40 0.16 2.88 Guilford 10.99 0.95 19.33 11.77 1.04 20.36 Halifax 9.79 0.30 5.16 10.73 0.31 5.19 Harnett 8.91 0.51 5.74 9.49 0.52 5.80 Haywood 2.44 0.21 2.08 2.51 0.21 2.18 Henderson 4.02 0.37 3.51 4.14 0.38 3.72 Hertford 5.54 0.13 2.34 6.11 0.13 2.38 Hoke 3.54 0.16 1.85 3.82 0.16 1.88 Hyde 4.91 0.05 1.45 5.48 0.05 1.45 Iredell 9.47 0.51 6.14 10.19 0.54 6.46 Jackson 2.45 0.21 1.23 2.52 0.21 1.30 Johnston 12.71 0.73 9.46 13.78 0.76 9.42 Jones 4.70 0.08 1.81 5.20 0.09 1.78 Lee 4.54 0.21 2.57 4.90 0.22 2.68 Lenoir 8.28 0.26 5.44 9.09 0.27 5.45 Lincoln 6.50 0.30 2.82 7.01 0.31 3.04 McDowell 2.28 0.20 1.30 2.35 0.21 1.37 Macon 1.85 0.14 0.98 1.90 0.14 1.02 Madison 1.87 0.18 1.41 1.93 0.18 1.42 Martin 5.52 0.23 3.59 5.93 0.24 3.54 Mecklenburg 4.61 0.99 25.87 4.97 1.12 28.14 Mitchell 1.47 0.11 0.91 1.52 0.11 0.93 Montgomery 2.44 0.18 1.81 2.53 0.19 1.83 Moore 4.97 0.35 3.49 5.20 0.37 3.66 Nash 9.24 0.42 7.76 10.02 0.44 7.75 Triad EAC Ozone Action Plan Page 76 March 31, 2004 Stationary Area Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC NewHanover 0.77 0.12 6.04 0.79 0.13 6.51 Northampton 5.09 0.16 2.65 5.55 0.17 2.60 Onslow 6.21 0.34 5.99 6.59 0.35 6.29 Orange 5.03 0.40 4.54 5.42 0.43 4.79 Pamlico 6.27 0.10 1.38 6.95 0.11 1.44 Pasquotank 12.97 0.14 3.18 14.47 0.14 3.37 Pender 5.90 0.28 2.47 6.30 0.29 2.61 Perquimans 6.91 0.09 1.76 7.68 0.09 1.79 Person 6.29 0.23 2.42 6.85 0.24 2.49 Pitt 9.95 0.46 9.13 10.78 0.47 9.36 Polk 1.57 0.13 0.70 1.61 0.13 0.74 Randolph 10.44 0.66 9.38 11.07 0.68 9.47 Richmond 2.58 0.20 2.01 2.71 0.21 2.11 Robeson 28.32 0.70 9.95 31.17 0.72 10.19 Rockingham 8.86 0.46 4.47 9.48 0.48 4.64 Rowan 9.50 0.46 5.66 10.28 0.49 6.08 Rutherford 4.44 0.31 2.68 4.64 0.33 2.96 Sampson 17.24 0.43 7.57 18.96 0.44 7.53 Scotland 7.55 0.17 2.36 8.33 0.17 2.47 Stanly 8.31 0.32 3.28 9.01 0.33 3.42 Stokes 4.56 0.26 2.42 4.82 0.27 2.45 Surry 6.15 0.37 4.01 6.47 0.38 4.16 Swain 1.22 0.10 0.50 1.26 0.10 0.52 Transylvania 1.75 0.16 1.08 1.80 0.17 1.14 Tyrrell 10.04 0.03 1.72 11.27 0.04 1.79 Union 23.79 0.55 7.20 26.31 0.58 7.68 Vance 4.19 0.19 2.43 4.52 0.19 2.51 Wake 10.49 1.24 24.71 11.31 1.35 26.08 Warren 4.18 0.16 1.44 4.52 0.16 1.47 Washington 12.80 0.08 2.51 14.34 0.09 2.60 Watauga 2.41 0.20 1.82 2.48 0.20 1.91 Wayne 16.32 0.48 7.91 17.91 0.49 8.07 Wilkes 4.79 0.37 3.35 4.95 0.38 3.49 Wilson 5.47 0.29 6.51 5.92 0.30 6.46 Yadkin 6.30 0.23 2.77 6.82 0.23 2.85 Yancey 1.67 0.12 0.90 1.72 0.13 0.92 Triad EAC Ozone Action Plan Page 77 March 31, 2004 Nonroad Mobile Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Alamance 29.54 2.98 2.37 33.64 2.91 2.04 Alexander 4.00 0.51 0.37 4.36 0.53 0.33 Alleghany 2.49 0.36 0.18 2.78 0.33 0.14 Anson 4.19 1.13 0.50 4.55 0.95 0.39 Ashe 3.91 0.44 0.41 4.54 0.43 0.44 Avery 5.37 0.52 0.59 6.39 0.47 0.65 Beaufort 13.85 2.81 2.74 15.07 2.51 2.30 Bertie 6.43 1.66 1.12 6.78 1.48 0.88 Bladen 8.96 1.81 1.44 10.50 1.59 1.66 Brunswick 27.00 2.10 4.70 30.90 1.88 4.16 Buncombe 48.93 4.51 4.43 57.45 4.28 4.27 Burke 14.79 2.10 1.51 16.50 2.05 1.51 Cabarrus 44.68 4.19 3.28 51.35 3.78 2.38 Caldwell 16.55 2.38 1.77 18.65 2.34 1.89 Camden 2.84 0.41 0.99 2.90 0.39 0.80 Carteret 49.17 1.82 14.18 54.95 1.90 12.43 Caswell 2.26 1.07 0.23 2.51 0.85 0.17 Catawba 47.03 5.15 4.20 53.29 5.17 3.95 Chatham 12.91 1.83 1.40 14.40 1.68 1.09 Cherokee 3.99 0.40 0.56 4.58 0.40 0.57 Chowan 4.05 0.47 1.14 4.45 0.46 1.03 Clay 2.19 0.15 0.43 2.72 0.14 0.54 Cleveland 21.51 2.13 1.75 24.58 2.08 1.52 Columbus 9.85 2.12 1.11 11.13 1.89 1.00 Craven 24.08 2.20 2.66 27.45 1.94 1.98 Cumberland 59.31 6.51 4.85 68.38 5.86 3.84 Currituck 15.63 0.77 4.69 17.55 0.77 4.24 Dare 46.18 1.33 18.14 49.76 1.54 15.68 Davidson 30.96 4.24 2.64 35.03 3.90 2.24 Davie 6.77 0.61 0.88 8.20 0.61 1.12 Duplin 10.19 2.36 0.97 11.18 2.13 0.73 Durham 70.50 9.63 6.04 79.17 9.06 5.09 Edgecombe 11.11 2.57 0.97 12.27 2.28 0.78 Forsyth 91.57 6.94 6.70 105.60 6.76 5.27 Franklin 8.37 1.05 0.78 9.71 0.93 0.70 Gaston 54.10 4.77 3.98 61.82 4.70 3.33 Gates 1.58 0.50 0.21 1.69 0.45 0.16 Graham 1.40 0.13 0.25 1.55 0.12 0.20 Granville 13.73 1.39 1.23 15.64 1.32 1.03 Greene 2.31 0.70 0.21 2.52 0.64 0.16 Guilford 194.02 14.69 14.06 226.39 13.97 10.89 Halifax 8.68 2.13 0.92 9.77 1.86 0.83 Triad EAC Ozone Action Plan Page 78 March 31, 2004 Nonroad Mobile Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Harnett 22.07 1.84 1.65 25.33 1.72 1.21 Haywood 11.35 1.08 1.15 13.38 1.00 1.19 Henderson 31.53 2.07 3.82 38.22 1.95 4.41 Hertford 4.08 0.54 0.48 4.74 0.50 0.48 Hoke 3.35 0.64 0.28 3.61 0.62 0.24 Hyde 25.38 1.93 11.68 25.59 1.94 9.56 Iredell 21.67 2.88 2.10 24.69 2.78 1.97 Jackson 6.55 0.51 0.75 7.75 0.46 0.76 Johnston 35.04 3.41 2.84 40.55 3.09 2.26 Jones 1.83 0.46 0.15 2.05 0.41 0.12 Lee 16.81 2.46 1.35 18.80 2.29 1.07 Lenoir 16.43 2.14 1.31 18.63 2.00 1.01 Lincoln 14.00 1.49 1.27 16.03 1.38 1.10 McDowell 7.93 1.84 1.14 9.18 1.61 1.36 Macon 10.89 0.53 0.97 12.89 0.50 0.91 Madison 1.73 0.56 0.17 1.96 0.45 0.13 Martin 4.71 1.32 0.51 5.37 1.16 0.51 Mecklenburg 351.64 23.31 24.93 298.78 21.99 18.42 Mitchell 3.61 1.02 0.51 4.27 0.85 0.61 Montgomery 4.89 0.71 0.58 5.34 0.66 0.48 Moore 27.52 1.89 1.95 31.86 1.73 1.41 Nash 21.77 2.69 1.71 24.83 2.47 1.32 NewHanover 58.02 4.59 5.80 67.25 4.20 4.55 Northampton 4.56 0.97 0.71 5.20 0.86 0.65 Onslow 26.34 3.52 3.92 29.60 3.21 3.31 Orange 31.55 3.66 3.18 37.13 3.19 3.09 Pamlico 9.11 0.88 3.58 9.63 0.85 3.09 Pasquotank 9.56 0.93 1.42 10.86 0.88 1.12 Pender 13.17 1.02 1.77 15.00 0.95 1.44 Perquimans 3.95 0.65 1.27 4.10 0.60 1.02 Person 8.34 0.85 0.80 9.41 0.82 0.64 Pitt 25.16 4.26 1.98 28.79 3.78 1.53 Polk 2.69 0.46 0.22 3.03 0.39 0.17 Randolph 27.23 2.82 2.20 30.77 2.85 1.94 Richmond 14.38 4.66 1.43 15.38 4.02 1.05 Robeson 19.63 5.97 1.91 21.45 5.21 1.62 Rockingham 15.35 2.44 1.55 17.39 2.26 1.63 Rowan 28.37 5.47 2.59 31.85 4.75 2.11 Rutherford 13.10 2.19 1.27 14.86 2.00 1.27 Sampson 10.67 2.15 0.92 11.89 1.96 0.70 Scotland 8.59 1.82 0.75 9.46 1.64 0.63 Stanly 16.77 2.09 1.54 19.02 1.96 1.29 Stokes 8.18 0.68 0.72 9.54 0.61 0.64 Triad EAC Ozone Action Plan Page 79 March 31, 2004 Nonroad Mobile Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Surry 30.76 1.96 2.43 35.44 1.98 2.05 Swain 4.84 0.35 1.35 6.47 0.32 1.88 Transylvania 15.89 0.68 2.79 20.28 0.67 3.77 Tyrrell 6.72 0.61 2.94 6.76 0.61 2.38 Union 47.65 3.89 3.56 55.34 3.56 2.71 Vance 6.24 1.24 0.75 6.84 1.14 0.62 Wake 242.05 18.83 17.61 281.90 17.33 12.59 Warren 3.51 0.70 0.58 3.85 0.56 0.43 Washington 5.43 1.03 1.44 5.68 0.95 1.16 Watauga 9.79 0.50 1.19 12.02 0.48 1.41 Wayne 26.05 3.51 2.10 29.98 3.27 1.71 Wilkes 16.62 1.37 1.38 19.09 1.32 1.17 Wilson 23.57 2.99 1.95 27.15 2.67 1.56 Yadkin 6.59 0.89 0.52 7.45 0.83 0.40 Yancey 7.75 0.37 0.87 9.32 0.34 0.94 Highway Mobile Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Alamance 93.84 13.48 8.34 54.81 9.52 5.01 Alexander 15.87 1.75 1.41 10.67 1.27 1.02 Alleghany 6.87 0.74 0.61 3.84 0.45 0.37 Anson 22.65 2.93 1.90 14.23 2.00 1.25 Ashe 15.28 1.61 1.36 8.98 1.03 0.86 Avery 13.78 1.66 1.18 7.98 1.05 0.73 Beaufort 31.89 3.55 2.81 19.36 2.35 1.81 Bertie 19.81 2.38 1.70 12.41 1.61 1.14 Bladen 29.89 3.22 2.65 18.60 2.18 1.78 Brunswick 67.90 8.19 5.82 39.68 5.53 3.69 Buncombe 149.98 23.51 13.10 87.96 16.25 7.83 Burke 65.51 12.34 5.64 36.98 7.79 3.38 Cabarrus 69.09 12.04 6.19 50.62 8.59 4.20 Caldwell 44.10 5.01 3.89 25.98 3.41 2.48 Camden 7.47 0.90 0.64 4.68 0.61 0.43 Carteret 43.77 5.41 3.74 22.53 3.19 2.10 Caswell 16.69 2.00 1.44 10.41 1.34 0.95 Catawba 113.03 15.57 10.08 66.68 10.71 6.25 Chatham 45.51 5.79 3.85 27.65 4.01 2.55 Cherokee 17.05 2.25 1.42 12.85 1.73 1.15 Chowan 8.16 0.92 0.72 4.87 0.60 0.45 Clay 6.05 0.68 0.53 3.81 0.46 0.36 Cleveland 68.95 10.19 5.97 37.44 6.17 3.49 Triad EAC Ozone Action Plan Page 80 March 31, 2004 Highway Mobile Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Columbus 43.72 5.12 3.80 27.16 3.52 2.47 Craven 57.77 6.75 5.06 34.07 4.53 3.19 Cumberland 197.16 28.43 17.85 108.27 18.56 10.31 Currituck 21.48 2.50 1.86 14.09 1.77 1.33 Dare 37.56 4.27 3.27 20.22 2.55 1.89 Davidson 105.57 17.25 9.73 61.60 11.04 6.06 Davie 32.17 7.98 2.67 20.32 5.05 1.78 Duplin 46.97 8.80 4.00 32.00 6.34 2.86 Durham 130.59 24.00 11.93 90.71 14.51 7.74 Edgecombe 41.11 4.72 3.61 23.96 3.17 2.28 Forsyth 188.14 33.73 18.97 125.17 19.34 12.44 Franklin 32.41 3.79 2.81 19.70 2.63 1.89 Gaston 87.61 16.61 8.66 56.34 9.20 5.28 Gates 8.85 1.12 0.75 5.30 0.73 0.47 Graham 4.84 0.50 0.43 3.31 0.39 0.32 Granville 48.49 9.82 5.02 27.96 5.43 3.29 Greene 14.77 1.63 1.30 9.41 1.14 0.89 Guilford 274.08 47.66 27.88 179.81 26.94 18.09 Halifax 48.63 11.44 4.09 31.41 7.19 2.75 Harnett 58.38 9.34 5.01 34.75 6.19 3.25 Haywood 58.30 14.16 4.81 33.85 8.92 2.99 Henderson 59.39 10.05 5.15 34.27 6.56 3.17 Hertford 15.08 1.71 1.32 9.26 1.14 0.87 Hoke 18.56 2.22 1.60 12.36 1.62 1.13 Hyde 4.39 0.48 0.39 2.61 0.32 0.25 Iredell 119.96 29.26 10.08 71.75 18.66 6.42 Jackson 36.42 4.77 3.04 23.49 3.29 2.08 Johnston 123.04 28.31 10.21 81.29 19.92 7.25 Jones 14.67 1.89 1.23 8.62 1.19 0.76 Lee 39.67 4.49 3.51 23.25 3.03 2.21 Lenoir 44.38 4.70 4.04 23.50 2.85 2.31 Lincoln 37.27 4.27 3.28 21.48 2.82 2.08 McDowell 42.05 9.85 3.48 26.32 3.48 2.37 Macon 24.61 3.09 2.08 15.13 2.02 1.37 Madison 13.33 1.64 1.14 8.25 1.10 0.75 Martin 25.08 3.06 2.15 15.47 3.65 1.34 Mecklenburg 341.23 67.76 34.75 222.60 36.34 21.26 Mitchell 9.55 1.09 0.83 5.95 0.75 0.55 Montgomery 26.55 3.60 2.27 18.18 2.61 1.66 Moore 53.39 5.90 4.73 29.76 3.77 2.87 Nash 93.59 17.62 7.97 53.90 10.92 4.94 NewHanover 81.67 9.12 7.49 48.41 6.14 4.72 Northampton 23.32 4.79 1.95 13.92 2.79 1.24 Triad EAC Ozone Action Plan Page 81 March 31, 2004 Highway Mobile Sources Emissions in tons/ day 2000 2007 County CO NOx VOC CO NOx VOC Onslow 67.91 7.55 6.03 35.66 4.56 3.41 Orange 62.40 18.80 5.30 44.95 11.91 3.63 Pamlico 9.21 0.93 0.83 5.79 0.64 0.56 Pasquotank 17.53 1.94 1.57 11.15 1.36 1.03 Pender 40.59 8.15 3.41 28.50 5.88 2.53 Perquimans 9.69 1.24 0.82 6.19 0.86 0.54 Person 21.02 2.25 1.89 12.96 1.51 1.23 Pitt 78.82 8.47 7.05 43.54 5.36 4.24 Polk 19.00 4.60 1.56 13.94 3.39 1.19 Randolph 97.79 13.69 8.46 57.60 9.14 5.31 Richmond 40.70 4.98 3.52 24.96 3.35 2.22 Robeson 107.26 20.38 9.20 61.34 12.86 5.62 Rockingham 66.14 7.51 5.82 37.21 4.86 3.57 Rowan 89.79 17.34 7.75 53.43 11.46 4.96 Rutherford 40.07 4.52 3.53 20.79 2.69 2.01 Sampson 51.06 8.35 4.42 32.73 5.69 2.97 Scotland 29.90 3.44 2.64 18.93 2.37 1.73 Stanly 37.66 4.01 3.39 20.69 2.53 2.03 Stokes 24.78 2.82 2.17 13.71 1.79 1.32 Surry 64.94 12.67 5.54 37.68 7.79 3.49 Swain 13.82 1.69 1.18 7.71 1.01 0.70 Transylvania 22.41 2.47 1.99 14.04 1.68 1.33 Tyrrell 3.78 0.49 0.32 2.31 0.33 0.20 Union 56.79 7.70 5.15 39.75 5.00 3.48 Vance 33.57 6.29 2.89 22.07 4.29 1.95 Wake 306.82 59.29 27.61 224.96 39.69 18.67 Warren 15.84 3.56 1.32 10.53 2.39 0.92 Washington 11.19 1.43 0.94 6.82 0.95 0.60 Watauga 25.14 3.08 2.17 15.08 2.02 1.34 Wayne 68.83 7.28 6.20 39.66 4.84 3.87 Wilkes 47.93 5.55 4.18 25.57 3.39 2.45 Wilson 61.49 10.12 5.37 35.49 6.44 3.32 Yadkin 34.98 7.13 2.92 21.93 4.42 1.92 Yancey 11.33 1.45 0.96 6.74 0.93 0.60 Triad Early Action Compact Ozone Action Plan Appendix B Page 1 March 31, 2004 APPENDIX B State Portion of June 30, 2003 Triad EAC Progress Report Triad Early Action Compact Ozone Action Plan Appendix B Page 2 March 31, 2004 Appendix B March 31, 2004 Early Action Plan Triad Early Action Compact Ozone Action Plan Appendix B Page 3 March 31, 2004 TRIAD EARLY ACTION COMPACT STATE PORTION  JUNE 30, 2003 PROGRESS REPORT Table of Contents Page MODELING Section 1 Introduction......................................................................................... 1 Section 2 Model Selection ................................................................................... 2 Section 3 Episode Selection................................................................................. 7 Section 4 Meteorological Modeling................................................................... 20 Section 5 Emissions Inventory.......................................................................... 33 Section 6 Modeling Status and Resource Constraints ..................................... 45 Appendix A Emission Sources by County............................................................. 47 Appendix B Conversion of MOBILE5 Registration Fractions to MOBILE6 Based Registration Fractions ......................................... 57 Triad Early Action Compact Ozone Action Plan Appendix B Page 4 March 31, 2004 MODELING Section 1  INTRODUCTION As a requirement of the Triad Early Action Compact ( EAC), the progress report due June 30, 2003, must include a status report regarding the air quality modeling. This report satisfies this requirement. Discussed in this report are the photochemical model selection, episode selection, meteorological model, emissions inventory development, and the modeling status.

The modeling analysis is a complex technical evaluation that begins by selection of the modeling system and selection of the meteorological episodes. NCDAQ decided to use the following modeling system:

  Meteorological Model: MM 5   This model generates hourly meteorological inputs for the emissions model and the air quality model, such as wind speed, wind direction, and surface temperature.

  Emissions Model: Sparse Matrix Operator Kernel Emissions ( SMOKE)  This model takes daily county level emissions and temporally allocates across the day, spatially locates the emissions within the county, and transfers the total emissions into the chemical species needed by the air quality model.

  Air Quality Model: MAQSIP ( Multi Scale Air Quality Simulation Platform)   This model takes the inputs from the emissions model and meteorological model and predicts ozone hour by hour across the modeling domain, both horizontally and vertically.

The following historical episodes were selected to model because they represent typical meteorological conditions in North Carolina when high ozone is observed throughout the State:

  July 10 15, 1995   June 20 24, 1996   June 25 30, 1996   July 10 15, 1997 The meteorological inputs were developed using MM5 and are discussed in detail in Section 4.

The precursors to ozone, Nitrogen Oxides ( NOx), Volatile Organic Compounds ( VOCs), and Carbon Monoxide ( CO) were estimated for each source category. These estimates were then spatially allocated across the county, temporally adjusted to the day of the week and hour of the day and speciated into the chemical species that the air quality model needs to predict ozone. The development of the emission inventories are discussed in detail in Section 5. The status of modeling work and issues that have been encountered are discussed in Section 6. Triad Early Action Compact Ozone Action Plan Appendix B Page 5 March 31, 2004 Section 2  MODEL SELECTION 2.1 Introduction To be useful in a regulatory framework, photochemical grid models and their applications must be defensible. Not only must the U. S. Environmental Protection Agency ( EPA) be convinced of this, but members of the regulated community ( stakeholders) as well. Failure to convince EPA can result in rejection of an implementation or maintenance plan. Failure to convince the regulated community can lead to diminished rule effectiveness and litigation. In none of these cases is the state's air quality goals advanced.

To ensure that a modeling study is defensible, care must be taken in the selection of the models to be used. The models selected must be scientifically appropriate for the intended application and be freely accessible to all stakeholders. Scientifically appropriate means that the models address important physical and chemical phenomena in sufficient detail, using peer reviewed methods. Freely accessible means that model formulations and coding are freely available for review and that the models are available to stakeholders, and their consultants, for execution and verification at no or low cost.

In the following sections we outline the criteria for selecting a modeling system that is both defensible and capable of meeting the study's goals.

2.2 Selection of Photochemical Grid Model 2.2.1 Criteria For a photochemical grid model to qualify as a candidate for use in an attainment demonstration of the 8 hour ozone National Ambient Air Quality Standards ( NAAQS), a State needs to show that it meets several general criteria.

  The model has received a scientific peer review   The model can be demonstrated applicable to the problem on a theoretical basis   Data bases needed to perform the analysis are available and adequate   Available past appropriate performance evaluations have shown the model is not biased toward underestimates   A protocol on methods and procedures to be followed has been established   The developer of the model must be willing to make the source code available to users for free or for a reasonable cost, and the model cannot otherwise be proprietary Triad Early Action Compact Ozone Action Plan Appendix B Page 6 March 31, 2004 2.2.2 Overview of MAQSIP The photochemical model selected for this study is the Multiscale Air Quality Simulation Platform ( MAQSIP). MAQSIP is a fully modularized three dimensional system with various options for representing the physical and chemical processes describing regional and urbanscale atmospheric pollution. The governing model equations for tracer continuity are formulated in generalized coordinates, thereby providing the capability of interfacing the model with a variety of meteorological drivers. The model employs flexible horizontal grid resolution with multiple multi level nested grids with options for one way and two way nesting procedures. In the vertical, the capability to use non uniform grids is provided. Current applications have used horizontal grid resolutions from 18 80 km for regional applications and 2 6 km for urban scale simulations, and up to 30 layers to discretize the vertical domain.

The MAQSIP framework with the detailed gas phase and aerosol model provides a modeling system that can be used for investigating the various processes that govern the loading of chemical species and anthropogenic aerosols at various scales of atmospheric motions from urban, regional to intercontinental scales. For example, MAQSIP has been used to support the Southeastern States Air Resources Management ( SESARM) project to produce seasonal simulations of ozone over eastern United States. The gas aerosol version of the MAQSIP ( hereinafter the MAQSIP PM) has been used in urban to regional scale applications over the eastern and western United States, and western Europe, to study the production and distribution of fine and coarse PM, and its effects on visibility and the radiation budget.

For regulatory application, a specific configuration of MAQSIP has been used in this study. This configuration of MAQSIP follows a series a sensitivity tests to determine the best performing modules. This configuration has the following components:

  Horizontal Coordinate System: Lambert Conformal Projection   Vertical Coordinate System: Non Hydrostatic Sigma Pressure Coordinates   Gas Phase Chemistry: Carbon Bond IV with Isoprene updates   Aqueous Phase Chemistry: Included in cloud package   Chemistry Solver: Modified QSSA   Horizontal Advection: Bott   Cloud Physics: Kain Fritsch parameterization and explicit, as needed   Horizontal Turbulent Diffusion: Fixed Kh   Vertical Turbulent Diffusion: K Theory   Photolysis Rates: Madronich   Dry Deposition: Resistance   Wet Deposition: Included in cloud package Triad Early Action Compact Ozone Action Plan Appendix B Page 7 March 31, 2004 2.3 Selection of Meteorological Model 2.3.1 Criteria Meteorological models, either through objective, diagnostic, or prognostic analysis, extend available information about the state of the atmosphere to the grid upon which photochemical grid modeling is to be carried out. The criteria for selecting a meteorological model are based on both the models ability to accurately replicate important meteorological phenomena in the region of study, and the model's ability to interface with the rest of the modeling systems  particularly the photochemical grid model. With these issues in mind, the following criteria were established for the meteorological model to be used in this study:

  Non Hydrostatic Formulation   Reasonably current, peer reviewed formulation   Simulates Cloud Physics   Publicly available on no or low cost   Output available in I/ O API format   Supports Four Dimensional Data Assimilation ( FDDA)

  Enhanced treatment of Planetary Boundary Layer heights for AQ modeling 2.3.2 Overview of MM5 The meteorological model selected for this study is the nonhydrostatic PSU/ NCAR Mesoscale Model Version 5 ( MM5). MM5 ( Dudhia 1993; Grell et al. 1994) is one of the leading threedimensional prognostic meteorological models available for air quality studies. It uses an efficient split semi implicit temporal integration scheme and has a nested grid capability that can use up to ten different domains of arbitrary horizontal resolution. This allows MM5 to simulate local details with high resolution ( as fine as ~ 1 km), while accounting for influences from great distances, using horizontal resolutions ranging to about 200 km.

MM5 uses a terrain following nondimensionalized pressure, or " sigma", vertical coordinate similar to that used in many operational and research models. In the nonhydrostatic MM5, the sigma levels are defined according to the initial hydrostatically balanced reference state so that these levels are also time invariant. The meteorological fields also can be used in other photochemical grid models with different coordinate systems by performing a vertical interpolation followed by a mass consistency reconciliation step.

The model contains two types of planetary boundary layer ( PBL) parameterizations suitable for air quality applications, both of which represent subgrid scale turbulent fluxes of heat, moisture, and momentum. A modified Blackadar PBL ( Zhang and Anthes 1982) uses a first order eddy diffusivity formulation for stable and neutral environments and a nonlocal closure for unstable regimes. The Gayno Seaman PBL ( Gayno, 1994) uses a prognostic equation for the second Triad Early Action Compact Ozone Action Plan Appendix B Page 8 March 31, 2004 order turbulent kinetic energy, while diagnosing the other key boundary layer terms. This is referred to as a 1.5 order PBL, or level 2.5, scheme ( Mellor and Yamada 1974).

Initial and lateral boundary conditions are specified for real data cases from mesoscale 3 D analyses performed at 12 hour intervals on the outermost grid mesh selected by the user. Surface fields are analyzed at three hour intervals. A Cressman based technique is used to analyze standard surface and radiosonde observations, using the National Meteorological Center's spectral analysis, as a first guess ( Benjamin and Seaman 1985). The lateral boundary data are introduced using a relaxation technique applied in the outermost five rows and columns of the coarsest grid domain.

For most traditional ( 1 hour standard) high ozone episodes, precipitation is not the dominant factor. On the other hand, precipitation events may have a greater impact on 8 hour average ozone episodes. The MM5 contains five convective parameterization schemes ( Kuo, Betts Miller, Fritsch Chappell, Kain Fritsch, and Grell). It also has an explicit resolved scale precipitation scheme ( Dudhia 1989) that solves prognostic equations for cloud water/ ice ( qc) and larger liquid or frozen hydrometeors ( qr). In addition the model contains a short and long wave radiation parameterization ( Dudhia 1989).

2.4 Selection of Emissions Processing System 2.4.1 Criteria The principal criterion for an emissions processing system is that it accurately prepares emissions files in a format suitable for the photochemical grid model being used. The following list includes clarification of this criterion and additional desirable criteria for effective use of the system.

  File System Compatibility with the I/ O API   File Portability   Ability to grid emissions on a Lambert Conformal projection   Report Capability   Graphical Analysis Capability   MOBILE6 Mobile Source Emissions   BEIS 2 Biogenic Emissions   Ability to process emissions for the proposed domain in a day or less.

  Ability to process control strategies   No or low cost for acquisition and maintenance   Expandable to support other species and mechanisms Triad Early Action Compact Ozone Action Plan Appendix B Page 9 March 31, 2004 2.4.2 Overview of SMOKE The emissions processing system selected for this study is the Sparse Matrix Operator Kernel Emissions ( SMOKE). SMOKE was developed to reduce the large processing times required to prepare emissions data for photochemical grid models. SMOKE processes both anthropogenic and biogenic emissions. Biogenic emissions are processed using an implementation of BEIS 3.

The modular structure of SMOKE ( see Appendix A) removes much of the redundant processing found in other systems. This will provide even greater savings of CPU time and disk space when SMOKE is used to process control strategies. Unlike other emission processing systems, SMOKE's structure makes each process ( i. e., gridding, speciation, temporal allocation, and control application) independent from the others. For example, to run a new control strategy, only the control model must be rerun, and the time stepped emissions multiplied by the matrices. This whole process takes only a few minutes to process a new point source strategy and a few additional minutes if area and mobile sources are also changed.

SMOKE has undergone an extensive process of testing and validation. It has been validated on a regional scale against EMS 95 using the OTAG 1990 inventory, and on a large urban scale against EPS 2.0 using North Carolina's State Implementation Plan ( SIP) inventory. SMOKE can be driven with inputs in EMS 95, EPS 2.0 or IDA format, and it can produce photochemical grid model ready emissions in forms suitable to drive UAM IV, UAM V, MAQSIP, CMAQ and SAQM. SMOKE has adopted the Models 3 Input/ Output Application Program Interface ( I/ O API) so the emissions files created by SMOKE are directly readable by Models 3, MCNC's MAQSIP, and the supporting analysis tools developed for these systems. Triad Early Action Compact Ozone Action Plan Appendix B Page 10 March 31, 2004 Section 3  EPISODE SELECTION 3.1 Introduction The episode selection process is critical to the success of the modeling study. Correctly identifying representative ozone episodes to model for several areas in North Carolina allows us to evaluate with confidence various control strategies for maintaining the NAAQS for ozone. Several factors influenced episode selection for this modeling study. In the following sections we outline the factors and considerations for episode selection, and then outline in detail the episodes selected for this modeling study.

3.2 Factors Influencing Episode Selection Several factors influenced episode selection for this modeling study. The primary factor influencing episode selection was the promulgation of an 8 hour standard for ozone and the litigation that followed. This led to uncertainties surrounding the implementation of the standard. Also, the form of the new 8 hour standard makes it less dependent on extreme events than the 1 hour standard. Therefore, meteorological scenarios associated with 8 hour exceedances were reviewed and considered for modeling. A combination of these factors led to choosing episodes where both the 1 hour and 8 hour standards were exceeded.

The EPA issued a new ambient air quality standard based on the daily maximum 8 hour averaged concentration for ozone in July 1997. In June of 1998, EPA revoked the 1 hour standard in North Carolina since all areas of the state had attained that standard. However, in the 1998 ozone season, North Carolina experienced its first violation of the 1 hour ozone standard since 1990 in the Charlotte area. Later, in May 1999, a D. C. District Court ruling instructed EPA that an intelligible principle for the setting of the new 8 hour standard had to be defined and that enforcement of the 8 hour standard was prohibited by the court until EPA had done so. In 1999, EPA reinstated the old 1 hour standard. The result of all of the changing policy and litigation is that the modeling study must shift its primary focus from a traditional analysis solely targeted at 1 hour averaged ozone values, to an analysis of both 1 hour and 8 hour averaged values. Analysis of episodes with exceedances of 1 hour and 8 hour standards will also allow an assessment of the differences that two standards may have on control strategy development and will indicate whether control strategies designed to meet the 8 hour standard will also be effective at reducing ozone levels below the 1 hour standard. The " dual" need to model 1 hour and 8 hour exceedances was a primary criterion in the episode selection process. Triad Early Action Compact Ozone Action Plan Appendix B Page 11 March 31, 2004 A second factor affecting the selection process was the form of the new standard. The 1 hour standard allowed 1 exceedance per year in a region on average with the design value being the 4th highest 1 hour value in that region over 3 years. This means that, in theory, only the 3 worst case episodes in a 3 year period can be removed from consideration for modeling. The design value under the 8 hour standard is calculated differently. It is the yearly 4th highest 8 hour value at each monitor, averaged over 3 years. With the new standard it is possible to " throw out" the 3 worst case episode days of each year, or approximately 9 days over 3 years for each monitor. Because the 4th high value is determined for each individual monitor, discarding days with higher values can result in the removal of more than 9 worst case days if the high readings for all monitors do not occur on the same days. For example, exceedances may be measured north of a city during days when the wind blows predominately from the south, but measured at monitors south of the city on other days when winds are northerly. Discarding days above the 4th highest measurement in this example could result in removal of more than 9 worst case episode days in three years. This makes the standard less dependent on extreme events.

3.3 Episode Selection Considerations The methodologies suggested in EPA's draft guidance for episode selection is the same for both the 1 hour and 8 hour standards. These methodologies were applied to the extent possible when attempting to choose episodes. The episode selection criterion was compromised to some extent by the need to simultaneously model multiple areas in North Carolina.

First, we considered a mix of episodes reflecting a variety of meteorological scenarios which frequently correspond with observed 8 hour daily maxima > 84 ppb at different monitoring sites. An analysis of each ozone episode was made using several sources of air quality and meteorological data to determine the episodes that would contribute the most to the modeling effort.

Secondly, we considered periods in which observed 8 hour daily maximum concentrations were within ± 10 ppb of each area's design value. Because modeling for the new 8 hour standard may capture some 1 hour exceedances, 8 hour averaged ozone concentrations were given primary consideration. The 8 hour design values were calculated statewide, with a focus on the three major urban areas of NC; Charlotte/ Gastonia, Greensboro/ Winston Salem ( the Triad), and Raleigh/ Durham ( RDU), using monitored values from 1994 2002. The average of each year's fourth highest daily 8 hour averaged maximum concentration for each monitor statewide was calculated and used as a guide for determining the episodes with concentrations within ± 10 ppb of the area's design value.

Finally, the temporal and spatial distribution of ozone throughout NC was also an important consideration. The new 8 hour standard brings areas such as Asheville, Fayetteville, Greenville/ Rocky Mount/ Wilson ( Down East), Hickory, and other various areas into nonattainment Therefore, it was necessary to choose episodes affecting those areas as well as the three major urban areas mentioned above. Episodes containing widespread ozone exceedances were given priority over those containing isolated exceedances. Also, the need to study the Triad Early Action Compact Ozone Action Plan Appendix B Page 12 March 31, 2004 cumulative effects of ozone build up over a number of days was recognized, so episodes of extended duration were given preference over single day exceedances.

Meeting all of the criteria in all areas is sometimes difficult. The episode selection criterion was compromised to some extent by the need to simultaneously model multiple areas. For example, during many " moderate" ozone events, ozone exceedances are not widespread throughout NC. Selection of these episodes can dramatically increase the number of modeled episodes needed to complete a thorough analysis of all non attainment areas across the state. On the other hand, episodes with exceedances in all non attainment areas often contain scattered extreme values.

To reduce the number of episodes to a manageable number, while also performing a complete analysis on each major urban area of NC, we made some compromise in the selection criteria. Ideally, no days with concentrations well above an area's design value would have been included in the selected episodes. However, on some days concentrations in one or two areas were found to be ideal for modeling while another area had observed concentrations well above its' ozone design value. Days such as these were included in the selected episodes due to the days' overall positive attributes.

3.4 Episode Selection Procedures Ambient data was used to determine the days that exceedances of the 1 hour and/ or 8 hour standard occurred in any of the major urban areas of NC from 1995 through 1997. These days were grouped into episodes and evaluated using the selection criteria discussed in the preceding section. An analysis of each ozone episode was made using several sources of air quality and meteorological data to determine the episodes that would contribute the most to the modeling effort.

Sets of ambient ozone data from 1995 1997 for the eastern US were plotted using Voyager Viewer software. The data were plotted for the eastern US using both hourly and 8 hour peak ozone concentrations. This permitted easy assessment of the spatial and temporal distribution of ozone throughout North Carolina as well as other areas of the eastern US and made it possible to easily determine whether the event was regional, sub regional, or local in nature. These plots combined with meteorological plots also indicated the potential for recirculation. In one episode, shifts in wind direction corresponded to shifts in the location of ozone peaks in the Charlotte area, suggesting that recirculation may have contributed to exceedances of both ozone standards.

In addition to the ambient data plots, several surface and upper air meteorological data sets were used to assess the atmospheric conditions contributing to the build up of ozone in each episode. Local Climatological Data sheets were used to collect diurnal data on temperatures, precipitation, and wind speed and direction. Daily weather maps were used to determine the location of surface fronts, troughs, and ridges as well as daily peak temperatures, precipitation, and the location of high and low pressure areas. Analysis charts ( 0000 Z and 1200 Z) for the surface, 850 mb, 700 mb, and 500 mb levels from the NOAA NCEP ETA meteorological computer Triad Early Action Compact Ozone Action Plan Appendix B Page 13 March 31, 2004 model were also used to assess conditions such as surface and upper air wind fields, temperatures, moisture, and the location of ridges and troughs. The conditions contributing to high levels of ozone were determined through chart analysis, and the type of meteorology was used to group episodes.

3.5 Episode Selection All days with ozone exceedances in any of the major urban areas of NC were considered in the episode selection process. These days were divided into episodes based on the distribution of measured ozone and the meteorological conditions that occurred throughout the period of exceedance. The meteorological characteristics of each episode were studied using the tools outlined in the previous section. All episodes will have some common characteristics. Warm temperatures, little or no precipitation, and relatively light winds are needed to produce ozone episodes. Typically, those conditions are characteristic of a surface high pressure area. The differences in the position, strength, and movement of the surface high pressure areas, along with differences in the mid to upper level wind patterns, allow us to discern several meteorological scenarios in which ozone episodes are likely. These meteorological scenarios are discussed in the following paragraphs.

Conditions that traditionally lead to large scale exceedances of the 1 hr standard result from the development of a broad surface high pressure area sprawled over the eastern third of the US and a large mid to upper level high pressure area near the Midwest ( Scenario 1   Eastern Stacked High). The mid to upper level ridge blocks the movement of fronts into the Eastern US and often results in very hot temperatures, little precipitation, and the buildup of high 1 hr and 8 hr ozone concentrations over much of the Midwest, Northeast, and South. As the mid to upper level ridge slowly slides eastward, it situates itself over the surface high pressure creating a " stacked high" over the Eastern US. The resulting large scale subsidence leads to very low vertical mixing heights prohibiting dispersion of precursor pollutants. The stagnant air mass from the " stacked high" scenario is prime for ozone episodes in the Eastern US. A trough can develop in east/ central NC during this scenario producing south southwesterly flow east of the trough and causing a large ozone concentration gradient. The presence of the trough can limit ozone readings east of the trough axis below the 1 hour and 8 hour standards throughout the episode. ( An example of these conditions is recorded in the July 14, 1995 Daily Weather Map [ Figure 3.5 1]. The 500 mb chart clearly shows the presence of a large high pressure area over the Midwest.)

The most frequently occurring meteorological scenario ( Scenario 2   Frontal Approach) is characterized by the movement of cold fronts toward NC and the presence of high pressure to the south or southwest of the state. Cold fronts often move toward NC during the summer months but are typically not strong enough to move completely through the state. They commonly become east west oriented and stall as far south as southern Virginia or northern sections of NC. The front may dip into northern portions of NC and then retreat as a warm front creating wind shifts or re circulation patterns. A southwesterly surface flow predominates as the front Triad Early Action Compact Ozone Action Plan Appendix B Page 14 March 31, 2004 approaches, but as the front moves into northern sections of NC, winds become more northerly. When the front retreats back to the north as a warm front, southwesterly winds return to the entire state. In the meantime, a zonal flow exists in the mid to upper levels. High temperatures range from the low to upper 90' s and dew points are in the upper 60' s to mid 70' s. Scattered exceedances of the 1 hour standard and widespread exceedances of the 8 hour standards may be realized in NC during these conditions. ( These conditions can be seen in the June 23, 1996 Daily Weather Map in [ Figure 3.5 2]. Note the presence of a stationary front along the NC/ VA border.) A third meteorological scenario ( Scenario 3   Canadian High) resulting in high buildups of ozone in NC is characterized by a surface high pressure area building in from the north, and a mid to upper level ridge that builds and sprawls to the west of NC in the Mid Mississippi Valley area. The position of the mid to upper level ridge produces a northerly flow aloft throughout this scenario. As the Canadian born surface high pressure builds into NC, it brings with it milder and drier air by means of a north northeasterly breeze. These conditions can lead to scattered exceedances of the 8 hour standard in NC. Temperatures are typically in the low to mid 80' s ( with dew points in the low to mid 60' s) during the beginning of this type of episode. However, as the center of the surface high pressure slides into NC, and the winds become light and variable, highs may reach the upper 80' s to low 90' s ( with dew points in the upper 60' s to low 70' s). Scattered exceedances of the 1 hour standard and widespread exceedances of the 8 hour standards may be realized in NC during these conditions. ( An example of these conditions is shown in Figure 3.5 3 [ June 28, 1996].)

The fourth meteorological scenario ( Scenario 4   Modified Canadian High with slight Tropical Influence), initially, is very similar to Scenario 3 above. Canadian born surface high pressure builds into NC delivering lower dew points and milder temperatures with a light northnortheasterly wind. This cool down is short lived however. As the high pressure center moves south of NC, a light southwesterly flow dominates, temperatures soar, and dew points increase. A mid to upper level ridge slowly sprawls eastward across the country, resulting in a very weak flow aloft. Occasionally, when the mid to upper level flow is very weak along the East Coast during the mid to late summer, tropical systems that work their way across the Atlantic Ocean can approach the Southeast US. Although it does not occur frequently, a tropical system lurking off the Carolina coast may influence conditions over NC in the form of subsidence in the mid toupper levels. Subsidence is usually distributed over a wide area away from tropical systems, and leads to cloudless skies and hot dry weather. The strength and proximity of the tropical system will influence the magnitude and extent of the subsidence and its' role in ozone formation in NC. ( An example of these conditions is shown in Figure 3.5 4 [ July 14, 1997].)

Meteorological scenarios other than the four identified above can result in ozone episodes. These " other" episodes, however, commonly do not meet the temporal or spatial requirements of the episode selection criteria for modeling defined in the U. S. EPA Draft Modeling Guidance for Ozone Attainment Demonstrations. One day ozone episodes can occur during a progressive meteorological pattern ( Scenario 5   Continental High in a progressive pattern). A surface highpressure area moving across the US and into NC for one day characterizes this scenario. This results in clear skies, light winds, and isolated 8 hour ozone exceedances. Triad Early Action Compact Ozone Action Plan Appendix B Page 15 March 31, 2004 An initial analysis of ambient data and Daily Weather Maps was used to place each of the ozone episodes into one of the four meteorological scenarios identified above. A list of the number of monitors with exceedances of the 8 hour standard in each of the major urban areas was compiled and reviewed. This information was used to exclude those episodes from each category that did not have sufficient spatial or temporal distribution to justify further study. A more detailed analysis of each of the remaining episodes was made using all sources of air quality and meteorological data to select the episodes that would best meet modeling objectives.

To better understand the impact of emission controls under the full range of meteorological conditions, one episode from each meteorological scenario was selected for modeling. The four episodes were selected because they represented a good cross section of events from both an air quality and meteorological perspective. They were also selected because observed ozone concentrations were close to the areas design value, and high ozone values were widespread throughout NC. One episode was selected from 1995 ( Scenario 1), two from 1996 ( Scenario 2 & Scenario 3), and one from 1997 ( Scenario 4). The two episodes selected from 1996 were separated by only two days during which time a strong cold front cleaned out the atmosphere as it passed through the state. The two episodes will be modeled simultaneously. This presents a good opportunity to test the ability of the air quality model to produce clean conditions in the middle of an episode.

These episodes provide a wide range of conditions that will provide the basis for a thorough analysis of the variety of factors that lead to ozone exceedances in NC. Control strategies can be tested under conditions that range from short duration ozone peaks above the 1 hour standard to extended periods of moderate levels of ozone producing widespread exceedances of the 8 hour standard. These episodes also range from multi regional to exceedances confined primarily to the state of NC.

The first episode ( Episode E1) is a 3 day episode that occurred from June 13   15, 1995. ( See the July 14 Daily Weather Map in Figure 3.5 1.) This episode was modeled by the Northeast Modeling Center as part of the OTAG study of ozone transport. This episode is a traditional ozone episode with high 1 hour and 8 hour averages throughout almost all areas of the South, East, and Midwest. A very strong upper level ridge developed to the west of NC and moved slowly to the east throughout the episode. On July 15th, the 1 hour peak reached 166 ppb in Atlanta, 179 ppb in Baltimore, and 154 ppb near Chicago. The highest readings were recorded in NC on July 14th; 129 ppb in Charlotte ( 99 ppb 8 hour) and 130 ppb in the Triad area ( 112 ppb 8 hour). A trough developed in eastern NC on July 14th producing south southwesterly flow east of the trough and causing a large ozone concentration gradient. Although a 1 hour peak of 129 ppb was measured in Charlotte, the peak ozone was only 39 ppb 100 miles to the east. The presence of the trough kept ozone readings in the Raleigh/ Durham area below the 1 hour and 8 hour standards throughout the episode. The trough moved to the west on July 15th and dropped 1 hour averages in Charlotte and the Triad below the standard; however, 8 hour concentrations remained above 0.085 ppm.

The first 1996 episode ( Episode E2) occurred June 21   24 1996. It is primarily a NC episode. ( See the June 23 Daily Weather Map in Figure 3.5 2.) Concentrations in most other areas of the South and East were lower than those in NC. This episode is dominated by the presence of a Triad Early Action Compact Ozone Action Plan Appendix B Page 16 March 31, 2004 front to the north and high pressure to the southwest of the state. The movement of the front and the monitored ozone readings indicate possible recirculation during the episode. Light southwesterly flow was present on 22 June and resulted in a 1 hour/ 8 hour peak of 133/ 110 ppb and 113/ 99 ppb northeast of Charlotte and Durham, respectively. As the front moved into northern portions of NC on the 23rd, winds became more northerly and concentrations in the Triad and Raleigh/ Durham area's fell. Ozone and precursor pollutants were pushed back into Charlotte and resulted in exceedances of the 1 hour and 8 hour standard at all three Mecklenburg county ozone monitors. On the 24th, the front retreated north as a warm front and southwesterly winds returned to the entire state. Ozone levels increased throughout northern portions of NC and 8 hour averaged concentrations between 90 and 100 ppb were recorded in the major urban areas of the Piedmont. One exceedance of the 1 hour standard ( 134 ppb) was measured at the Rockwell site, northeast of Charlotte.

A stronger front moved toward NC on the 25th touching off storms and dropping ozone readings. The front passed through the state by the 26th and concentrations remained low. An upper level ridge began to build to the west of NC and surface high pressure over Canada moved southward throughout episode ( Episode E3) ( June 27   29, 1996) and settled into western NC by the 29th. ( See the June 28 Daily Weather Map in Figure 3.5 3.) Northerly winds were predominant at the surface and upper levels. High temperatures remained 90 and below in NC and much of the eastern half of the US during this period. Dew point temperatures were relatively low and winds were light enough to produce 8 hour exceedances in many areas of NC on the 28th and 29th. As high pressure remained over western NC, ozone concentrations continued to rise throughout the episode. Exceedances of the 1 hour standard were measured at two monitors in Charlotte on the 29th.

The final episode selected for analysis ( Episode E4) occurred July 11   15, 1997. ( See the July 14 Daily Weather Map in Figure 3.5 4.) The previous three episodes did not capture typical ozone behaviors in the center city areas of the Triad and the Triangle. The selection of this episode also was driven by the need to model an episode that captured ozone events in areas such as Greenville, Fayetteville, and Hickory. The most distinctive aspect of this episode, however, is that a 1 hour exceedance occurred in the Triangle area on the July 14th. No other episode captures a 1 hour exceedance in this region. On the first three days of the episode, meteorological conditions were very similar to those in episode E3. On the 14th and 15th, however, the surface high pressure center moved over NC, the mid to upper level flow relaxed, and a tropical depression off the NC coast strengthens into Tropical Storm " Claudette". It is possible that the tropical system influenced conditions in NC ( especially Eastern NC) on the 14th and 15th. Temperatures soared into the mid 90' s with dew points in the mid to upper 60s. The backward air parcel trajectories from Rocky Mount, NC ( shown in Figure 3.5 5), illustrates the possible influence from the tropical system ( Note the subsidence at mid levels from 0Z   20Z on the 14th.) Exceedances of the 8 hour standard were recorded in North Carolina, South Carolina and Virginia as the surface high pressure center moved over NC, the mid to upper level flow aloft weakened, and the tropical system made it's nearest approach. Triad Early Action Compact Ozone Action Plan Appendix B Page 17 March 31, 2004 Figure 3.5 1 Daily Weather Maps for July 14, 1995 Triad Early Action Compact Ozone Action Plan Appendix B Page 18 March 31, 2004 Figure 3.5 2 Daily Weather Maps for June 23, 1996 Triad Early Action Compact Ozone Action Plan Appendix B Page 19 March 31, 2004 Figure 3.5 3 Daily Weather Maps for June 28, 1996 Triad Early Action Compact Ozone Action Plan Appendix B Page 20 March 31, 2004 Figure 3.5 4 Daily Weather Maps for July 14, 1997 Triad Early Action Compact Ozone Action Plan Appendix B Page 21 March 31, 2004 Figure 3.5 5 Backward Air Parcel Trajectories for July 14, 1997 Triad Early Action Compact Ozone Action Plan Appendix B Page 22 March 31, 2004 Table 3.5 1 Features of Each Selected Episode E1 E2 E3 E4 Synoptic Features Large blocking upper level High over Midwest slides eastward over the large surface High over Eastern US. Front to the north. High pressure center SW of NC. Front moves into NC, then retreats as a warm front. Canadian surface High moves south into NC. Upper level ridge over middle of country. Canadian surface High moves south of NC. Upper level flow weakens. Possible influence from tropical system of the coast. Scale Multi regional exceedances of 1 hr & 8 hr standard. Primarily NC. Primarily NC. Multi regional exceedances of 1 hr and 8 hr standard.

Temperatures Mid  upper 90' s in NC. 90' s to 100' s throughout MW, NE, & South. Low  mid 90' s in NC and South. mid 80' s  low 90' s MW & NE. Upper 80' s in NC. Mid  upper 80' s NE & MW. Low 90' s in South. Initially upper 80' s, then mid to upper 90' s for NC and Mid Atlantic.

Dew Pt Temps Upper 60' s  low 70' s in NC. As high as low 80' s NE & MW. Low 70' s. Low to mid 60' s. Upper 60' s   low 70' s in NC and Mid Atlantic.

Local Features North to South trough over east/ central NC. Clean air east of trough effects O3 in CLT & RDU. Front dips into northern NC & retreats as warm front creating wind shifts and re circulation patterns. Influence of Canadian High. Dry air & northerly winds at surface & upper levels. Stagnating winds throughout atmosphere. Possible influence from tropical system in eastern NC.

Ozone Conc's 1 hr around 130 in GSO, CLT. 170' s in Baltimore, 160' s in Atlanta, 150' s in MW. Multi day exceedances of 8 hr in 3 major areas of NC. 1 hr exceedances on 3 days in CLT. Multi day exceedances of 8 hr in 3 major areas of NC. 1 hr exceedances in GSO & CLT on last day. Multi day exceedances of 8 hr in all major NC metro areas. 1 hr exceedances on 2 days ( 1 RDU & 1 CLT). Triad Early Action Compact Ozone Action Plan Appendix B Page 23 March 31, 2004 Section 4  METEOROLOGICAL MODELING 4.1 Introduction Meteorological data needed for the MAQSIP application were obtained from the MM5 modeling system. Numerical meteorological models solve the governing equations of atmospheric physics over time and space in order to provide cell specific meteorological inputs into the photochemical model.

Prognostic models such as MM5 are particularly advantageous ( as opposed to objective/ diagnostic techniques for meteorological input development) over domains in which atmospheric circulation not adequately characterized by existing data networks play an important role in pollutant transport. Within the modeling domain topographical flow, sea breeze circulation, and the effects of differential UV attenuation due to clouds will need to be accurately simulated in order to successfully model ozone formation, transport, and destruction within the airshed.

4.2 Grid Definition Table 4.2 1 lists the specifications of each of the four MM5 nested grids. Figure 4 1 through 4 3 illustrates the MM5 domains utilized for the modeling. Grids 01 ( 108 km) and 02 ( 36 km) are more expansive than the outermost MAQSIP grid and are intended to capture the broad, synoptic scale meteorological features of the episodes. Grids 03 ( 12 km) and 04 ( 4km) encompass the corresponding fine mesh domains within MAQSIP and are required to capture the mesoscale elements of pollutant transport within the airshed. Since the 4km domain configuration varies with each episode, the numbers in Table 4.2 1 for D 04 represent the differing specifications, starting with the 1995 case.

Table 4.2 1. MM5 Grid Specifications Grid Resolution ( km) East West Cells (#) North South Cells (#) Time Step ( s)

D 01 108 54 42 300 D 02 36 60 60 100 D 03 12 81 63 36 D 04 4 69, 126, 114 69, 75, 75 12 Triad Early Action Compact Ozone Action Plan Appendix B Page 24 March 31, 2004 Figure 4.2 1 The 1995 MM5 Modeling Domain and Grids Figure 4.2 2 The 1996 MM5 Modeling Domain and Grids Triad Early Action Compact Ozone Action Plan Appendix B Page 25 March 31, 2004 Figure 4.2 3 The 1997 MM5 Modeling Domain and Grids Given that the emphasis of the meteorological modeling is mid latitudinal, a Lambert Conformal map projection has been chosen. The horizontal grid uses an Arakawa Lamb B staggering of the wind vector components; scalar variables are defined at cell centers. In the vertical, 26 layers are modeled using terrain following coordinates ( sigma coordinates). With the exception of vertical velocity, all state variables are defined at half sigma levels ( i. e., the midpoint of layer depth). The pressure at the top of the model is 100 millibars.

Table 4.2 2 shows an estimated vertical grid resolution for the meteorological model assuming standard atmosphere. Triad Early Action Compact Ozone Action Plan Appendix B Page 26 March 31, 2004 Table 4.2 2. Vertical Grid Resolution for the Meteorological Model ( MM5) Level SIGMA Pressure ( mb) Height ( m) Thickness ( m) 0 1.000 1000.0 0.0 0.0 1 0.995 995.5 38.0 38.0 2 0.987 988.3 99.2 61.1 3 0.974 976.6 199.3 100.1 4 0.956 960.4 339.5 140.2 5 0.936 942.4 497.5 158.1 6 0.913 921.7 682.4 184.8 7 0.887 898.3 895.4 213.0 8 0.857 871.3 1146.8 251.4 9 0.824 841.6 1430.8 284.0 10 0.790 811.0 1732.0 301.2 11 0.750 775.0 2098.3 366.3 12 0.700 730.0 2576.1 477.8 13 0.650 685.0 3078.3 502.2 14 0.600 640.0 3607.9 529.6 15 0.550 595.0 4168.6 560.7 16 0.500 550.0 4764.7 596.1 17 0.450 505.0 5401.6 636.9 18 0.400 460.0 6086.2 684.6 19 0.350 415.0 6827.3 741.0 20 0.300 370.0 7636.3 809.1 21 0.250 325.0 8529.1 892.8 22 0.200 280.0 9528.0 998.8 23 0.150 235.0 10665.7 1137.7 24 0.100 190.0 12021.8 1356.1 25 0.050 145.0 13742.3 1720.5 26 0.000 100.0 16094.8 2352.5 The meteorological model used for the 1995 modeling episode, MM5 version1, used the postprocessor Meteorology Chemistry Interface Processor ( MCIP) to prepare the MAQSIP model inputs. This post processor could collapse some of the meteorological layers so that the MAQSIP model could run with fewer layers and reduce the processing time. North Carolina ran a number of sensitivity runs, collapsing some of the upper layers, to see if the air quality predictions were adversely affected. From this analysis, it was determined that the minimum number of layer that the MAQSIP model could run with was 16 layers without differing significantly from running the model with all 26 layers. The first 12 layers of the meteorological model are mapped directly and the upper 14 MM5 layers are collapsed into 4 MAQSIP layers. The estimated vertical grid resolution for the MAQSIP model for the 1995 modeling episode is shown in Table 4.2 3. Triad Early Action Compact Ozone Action Plan Appendix B Page 27 March 31, 2004 Table 4.2 3. Vertical Grid Resolution for MAQSIP for the 1995 Episode Level Height ( m) Thickness ( m) 0 0.0 0.0 1 38.0 38.0 2 99.2 61.1 3 199.3 100.1 4 339.5 140.2 5 497.5 158.1 6 682.4 184.8 7 895.4 213.0 8 1146.8 251.4 9 1430.8 284.0 10 1732.0 301.2 11 2098.3 366.3 12 2576.1 477.8 13 4168.6 1592.5 14 6827.3 2658.7 15 10665.7 3838.4 16 16094.8 5429.1 For the 1996 and 1997 modeling episodes, newer versions of the meteorological model were used. The post processor for the new versions is Meteorology Coupler ( MCPL) and it cannot collapse the meteorological data into a format that the MAQSIP model can use. Therefore, the photochemical model runs with 26 layers, mapping the meteorological data directly, for the 1996 and 1997 episodes.

4.3 MM5 Physics Options One way nested grids Non hydrostatic dynamics Four dimensional data assimilation ( FDDA):   analysis nudging of wind, temperature, and mixing ratios every 12 hours   nudging coefficients range from 1.0 * 10 5 s 1 to 3.0 * 10 4 s 1   No initial FDDA for 12 km and 4 km grids Explicit moisture treatment:   3 D predictions of cloud and precipitation fields   simple ice microphysics   cloud effects on surface radiation   moist vertical diffusion in clouds   normal evaporative cooling Boundary conditions:   relaxation inflow/ outflow ( Grid 01) Triad Early Action Compact Ozone Action Plan Appendix B Page 28 March 31, 2004   time dependent ( Grids 02, 03, & 04)   rigid upper boundary Cumulus cloud parameterization schemes:   Anthes Kuo ( Grid 01)   Kain Fritsch ( Grids 02 and 03) 1995 & 1996 episodes, Grell ( Grids 02 and 03) 1997   no cumulus parameterization ( Grid 04) Full 3 dimensional Coriolis force Drag coefficients vary with stability Vertical mixing of momentum in mixed layer Virtual temperature effects Planetary boundary layer process parameterization:   Modified Blackadar scheme ( Grids 02, 03 and 04) for 1996 and 1997 episodes and Grid 02 for 1995 episode; Gayno Seaman scheme ( Grids 03 and 04) for 1995 episode. Surface layer parameterization:   fluxes of momentum, sensible and latent heat   ground temperature prediction using energy balance equation   13 land use categories Atmospheric radiation schemes:   Simple cooling   Long and short wave radiation scheme Several application specific modifications:   m5_ dry. mods  lowers MM5 soil moisture when appropriate locally   mavail_ adj. mods  changes soil moisture as a function of soil type as needed   m5_ flyer. mods  modifications to optimize on NCSC CRAY T 90   kfbm_ edss. mods  writes special Kain Fritsch meteorological data   m5_ height. mods  calculates MM5 layer heights correctly for non hydrostatic   m5_ epafiles. mods  writes additional data out to air quality model   m5_ blkdr_ hts. mods  modifies PBL height calculations to a VMM scheme 4.4 Inputs Table 4.4 1 describes the terrain and land use fields input into MM5 for the modeling.

Table 4.4 1 Terrain and Land Use Inputs to MM5 Grid Terrain origin Terrain resolution Land use origin Land use resolution G 01 PSU/ NCAR 30 minute PSU/ NCAR 30 minute G 02 GDC 10 minute PSU/ NCAR 10 minute G 03* GDC 5 minute PSU/ NCAR 5 minute G 04* GDC 5 minute PSU/ NCAR 5 minute Triad Early Action Compact Ozone Action Plan Appendix B Page 29 March 31, 2004 * Land use data were slightly modified in the Charlotte area to minimize the number of cells characterized as urban. Also, several cells along the NC/ SC coastline were modified to reflect mixed forest  wetland as opposed to water.

The TOGA ( 2.5 by 2.5 degrees) data set was used to provide a first guess interpolation of meteorological data to the horizontal modeling grid. Climatological averages of sea surface temperature were used to characterize ocean temperatures. Three and six hourly NWS data ( first order) were used to develop the surface analysis fields. Standard twice daily rawinsonde data from the NWS were used in the preparation of aloft FDDA analysis fields.

4.5 Performance Evaluation The standard set of objective metrics to evaluate model performance for various meteorological parameters were generated for this project. The basic methodology employed used the base variables that were available for observational nudging. These variables include temperature, water vapor mixing ratio, east west wind and south north wind. Note that only the wind components are actually used for observational nudging. The observed winds have been rotated to the model projection ( Lambert Conformal). The model/ obs pairs are matched on a grid cell basis; no bilinear interpolation is performed. If more than one observation lies within a cell, the observations are averaged and the value is treated as if it were a single observation. For the wind components and mixing ratio, layer 1 (~ 38m) values are used. Temperatures are adjusted to 1.5 meters by logarithmically interpolating between the layer 1 temperature and the " skin" temperature. The results of this interpolation were compared with a more sophisticated methodology in which the interpolation varies with stability class, and we found little significant differences between the two. Since observational nudging was employed only at 12 km and 4 km resolutions, performance statistics were produced only for those grids.

A limited sample of the performance metrics for each episode is provided in Figures 4.5 1 through 4.5 7 below. For an exhaustive review of the meteorological modeling results, please visit: http:// www. emc. mcnc. org/ projects/ NCDAQ/ PGM/ results/ index. htm Triad Early Action Compact Ozone Action Plan Appendix B Page 30 March 31, 2004 Figure 4.5 1 Temperature performance metric   1995 episode  4km domain Figure 4.5 2 Example Temperature Metric  1995 episode  12 km domain Triad Early Action Compact Ozone Action Plan Appendix B Page 31 March 31, 2004 Figure 4.5 3 Temperature performance metric   1996 episode  4km domain Figure 4.5 4 Example Temperature Metric  1996 episode  12 km domain Triad Early Action Compact Ozone Action Plan Appendix B Page 32 March 31, 2004 Figure 4.5 5 Temperature performance metric   1996 episode  4km domain Figure 4.5 6 Example Temperature Metric  1997 episode  12 km domain Triad Early Action Compact Ozone Action Plan Appendix B Page 33 March 31, 2004 Figure 4.5 7 Example Layer 1 Wind Vector Metric  1995 episode  12 km domain Blue vectors= observations, black vectors= model Triad Early Action Compact Ozone Action Plan Appendix B Page 34 March 31, 2004 Currently, there is no accepted standard by which to judge meteorological model performance. Modelers usually calculate the basic statistics such as bias, error, or index of agreement and compare their results with the same quantities from prior and similar modeling exercises. The problem with such an approach is that these numbers are a function of the domain size modeled, the length of the simulation, and the meteorology being modeled. In this modeling study, the modeling team, including a number of air quality meteorologists, examined all of the meteorological modeling output both quantitatively through statistical metrics and qualitatively through a series of graphical metrics.

When passing final judgment regarding the accuracy of a meteorological simulation, the modeling team concluded that the results satisfactorily address the following questions:

A. Do the model results fit our conceptual understanding? The model replicates the observed synoptic pattern, placing surface pressure systems in the proper location and matches the upper air pattern.

B. Are diurnal features adequately captured? The diurnal cycle is adequately Triad Early Action Compact Ozone Action Plan Appendix B Page 35 March 31, 2004 represented in the model. For example, the mixing heights increase during the day and collapse at night in a reasonable way. Similarly temperatures, summertime convection, and winds show diurnal variation.

C. Is the vertical mixing appropriate? The PBL depth and evolution is well modeled.

D. Are clouds reasonably well modeled? Secondary quantities such as clouds are particularly useful to analyze since they are not " nudged" to the observations. We see that on a synoptic scale the model clouds will generally match the observations. Convective clouds are unlikely to occur precisely in the right place and at the right time, but the general region/ time of convective development is adequate.

E. Do the wind fields agree with the observations? The model adequately captures the observed wind fields so that transport in the subsequent air quality runs is done correctly.

G. Do the temperature and moisture fields generally match the observations? These first order scalar quantities are well captured by the model.

H. Do the meteorological fields produce acceptable air quality results? While air quality models can have problems of their own, many times poor air quality modeling results occur due to problems with the input meteorological fields. This is often a good test to determine whether the meteorological model adequately predicts the fields to which the air quality model is most sensitive. A number of air quality runs were conducted to test the sensitivity to different meteorological inputs. Triad Early Action Compact Ozone Action Plan Appendix B Page 36 March 31, 2004 Section 5  EMISSIONS INVENTORY 5.1 Introduction There are five different emission inventory source classifications, stationary point and area sources, off road and on road mobile sources, and biogenic sources.

Stationary point sources are those sources that emit greater than a specified tonage per year and the data is provided at the facility level. Stationary area sources are those sources whose emissions are relatively small but due to the large number of these sources, the collective emissions could be significant ( i. e., dry cleaners, service stations, etc.) These type of emissions are estimated on the county level. Off road mobile sources are equipment that can move but do not use the roadways, i. e., lawn mowers, construction equipment, railroad locomotives, aircraft, etc. The emissions from these sources, like stationary area sources, are estimated on the county level. On road mobile sources are automobiles, trucks, and motorcycles that use the roadway system. The emissions from these sources are estimated by vehicle type and road type and are summed to the county level. Biogenic sources are the natural sources like trees, crops, grasses and natural decay of plants. The emissions from these sources are estimated on a county level.

In addition to the various source classifications, there are also various types of emission inventories. The first is the base year or episodic inventory. This inventory is based on the year of the episode being modeled and is used for validating the photochemical model performance.

The second inventory used in this project is the " current" year inventory. For this modeling project it will be the 2000 emission inventory, which is the most current. This inventory is processed using all of the different meteorological episodes being studied. The photochemical modeling is processed using the current year inventory and those results are used as a representation of current air quality conditions.

Next is the future year base inventory. For this type, an inventory is developed for some future year for which attainment of the ozone standard is needed. For this modeling project the future years will be 2007 and 2012. It is the future year base inventories that control strategies and sensitivities are applied to determine what controls, to which source classifications, must be made in order to attain the ozone standard. Triad Early Action Compact Ozone Action Plan Appendix B Page 37 March 31, 2004 In the sections that follow, the base year inventories used for each source classifications are discussed. Emission summaries by county for the entire State are in Appendix A.

5.2 Stationary Point Sources Point source emissions are emissions from individual sources having a fixed location. Generally, these sources must have permits to operate and their emissions are inventoried on a regular schedule. Large sources having emissions of 100 tons per year ( tpy) of a criteria pollutant, 10 tpy of a single hazardous air pollutant ( HAP), or 25 tpy total HAP are inventoried annually. Smaller sources have been inventoried less frequently. The point source emissions data can be grouped into the large electric utility sources and the other point sources.

5.2.1 LARGE UTILITY SOURCES The inventory used for the large utility sources is the May 1999 release of the NOx SIP call base year modeling foundation files obtained from the USEPA Office of Air Quality Planning and Standards ( OAQPS). The base year for this utility data is 1996. This data is provided in EMS 95 format. The emissions data for the utilities is episode specific CEM data and is specific for each source for each hour of the modeling episode. This data comes from the USEPA Acid Rain Division ( ARD). Since only NOx emissions are measured, the CO and VOC emissions are calculated from the NOx emissions using emission factor ratios ( CO/ NOx and VOC/ NOx) for the particular combustion processes at the utilities.

5.2.2 Other Point Sources The inventory used to model the other point sources is the May 1999 release of the NOx SIP call base year modeling foundation files obtained from the USEPA OAQPS. This data is based on 1995 emissions and is provided in EMS 95 format. For the 1996 and 1997 modeling episode, emissions were grown using Bureau of Economic Analysis ( BEA) growth factors. The North Carolina sources were an exception. These emissions are true 1996 emissions for the larger VOC and NOx sources. In addition, emissions for forest fires and prescribed burns are treated as point sources and are episode specific similar to CEM data.

The emissions summary for the 1996 episodes for the counties in the Triad EAC area is listed in Table 5.2 1. These emissions represent a typical weekday, Thursday's ( June 20th), emissions and are in tons per day. In some instances a county may not have had emissions for the 20th but did have emissions during the modeling episode due to forest fires or prescribed burns that were treated as point sources.

Table 5.2 1 Stationary Point Source Emissions Triad Early Action Compact Ozone Action Plan Appendix B Page 38 March 31, 2004 County CO NOx VOC Alamance 0.061 0.676 0.960 Caswell 0.000 0.000 0.000 Davidson 2.466 12.859 23.927 Davie 0.078 0.039 3.841 Forsyth 1.917 8.835 20.874 Guilford 0.158 1.829 40.535 Randolph 0.021 0.058 2.528 Rockingham 5.954 33.903 7.896 Stokes 7.872 341.620 0.945 Surry 5.356 0.942 5.817 Yadkin 0.000 0.000 0.092 Total 23.883 400.760 107.413 5.3 Stationary Area Sources The base year inventory for the stationary area sources is the May 1999 release of the NOx SIP call base year modeling foundation files obtained from the USEPA OAQPS. This data is based on 1995 and is provided in EMS 95 format. For the 1996 and 1997 base years, the NOx SIP call foundation files will be grown to the respective year by use of Bureau of Economic Analysis ( BEA) growth factors or projected population growth obtained from the US Census Bureau.

The exception to this is for North Carolina where a 2000 base year inventory was generated by NCDAQ following the current methodologies outlined in the Emissions Inventory Improvement Program ( EIIP) Area Source Development Documents, Volume III ( http:// www. epa. gov/ ttn/ chief/ eiip/ techreport/ volume03/ index. html). This data was backcasted to the base years via growth factors developed with EPA's Economic Growth Analysis System ( EGAS) version 4.0.

The emissions summary for the 1996 episodes for the counties in the Triad EAC area is listed in Table 5.3 1. These emissions represent a typical weekday, Thursday's ( June 20th), emissions and are in tons per day.

Table 5.3 1 Stationary Area Source Emissions County NOx VOC CO Alamance 0.74 7.71 3.51 Caswell 0.23 1.65 2.46 Davidson 1.35 10.66 6.02 Davie 0.26 2.57 2.52 Forsyth 1.54 14.36 5.33 Guildford 4.13 26.45 10.27 Triad Early Action Compact Ozone Action Plan Appendix B Page 39 March 31, 2004 Randolph 0.78 9.82 5.89 Rockingham 1.03 5.91 6.30 Stokes 0.27 2.65 2.26 Surry 0.25 6.09 3.87 Yadkin 0.16 3.54 2.82 Total 10.75 91.42 51.24 5.4 Off Road Mobile Sources The off road mobile sources can be broken down into two types of sources; those calculated within the USEPA NONROAD mobile model and those that are not. For the sources that are calculated within the NONROAD mobile model, a base year inventory was generated for the entire domain for each of the base years. The model version used is the Draft NONROAD2002 distributed for a limited, confidential, and secure review in November 2002. If the final version or any newer draft versions of this model is released by the USEPA, an assessment of the difference in the emission estimations will be made to determine if a new inventory must be generated and processed through the photochemical model.

The sources not calculated within the NONROAD model include aircraft engines, railroad locomotives and commercial marine vessels. The base year inventory for these sources was the May 1999 release of the NOx SIP call base year modeling foundation files obtained from the USEPA OAQPS. This data is based on 1995 and is provided in EMS 95 format. For the 1996 and 1997 base years, the NOx SIP call foundation files were grown to the respective year by use of Bureau of Economic Analysis ( BEA) growth factors.

The exception to this was for North Carolina where a 1995 base year inventory was generated by NCDAQ for aircraft engines and railroad locomotives. This data was then grown to the other base years via BEA growth factors or other State specific data.

The emissions summary for the 1996 episodes for the counties in the Triad EAC area is listed in Table 5.4 1. These emissions represent a typical weekday, Thursday's ( June 20th), emissions and are in tons per day.

Table 5.4 1 Off Road Mobile Source Emissions County NOx VOC CO Alamance 2.58 2.59 29.18 Caswell 0.40 0.22 2.26 Davidson 3.43 2.88 30.28 Davie 0.70 0.84 7.20 Forsyth 6.50 7.62 89.05 Guildford 13.51 16.09 182.94 Randolph 2.79 2.43 27.26 Rockingham 1.80 1.54 15.60 Triad Early Action Compact Ozone Action Plan Appendix B Page 40 March 31, 2004 Stokes 0.61 0.77 7.77 Surry 1.76 2.63 28.71 Yadkin 0.75 0.58 6.52 Total 34.83 38.19 426.77 5.5 Highway Mobile Sources In order to accurately model the mobile source emissions in the EAC areas, the newest version of the MOBILE model, MOBILE6.2, was used. This model was released by EPA in 2002 and differs significantly from previous versions of the model. Key inputs for MOBILE include information on the age of vehicles on the roads, the speed of those vehicles, what types of road those vehicles are traveling on, any control technologies in place in an area to reduce emissions Triad Early Action Compact Ozone Action Plan Appendix B Page 41 March 31, 2004 for motor vehicles ( e. g., emissions inspection programs), and temperature. Baseline estimates were created for the episode June 19   July 1, 1996.

5.5.1 SPEED ASSUMPTIONS Emissions from motor vehicles vary with the manner in which the vehicle is operated. Vehicles traveling at 65 mph emit a very different mix of pollutants than the car that is idling at a stoplight. In order to estimate emissions from vehicles for a typical day, North Carolina Department of Transportation ( NCDOT) provided speeds for each of the urban areas across the state and in some cases for different times of the day. To reflect the most current assumptions on the speed of vehicles in different areas across the state, the latest conformity report was used which reflected speeds developed through travel demand modeling for the urban areas. Separate speed profiles were created for Wake County ( covering Durham and Orange Counties) Greensboro, Winston Salem, Mecklenburg County ( covering Gaston County), and " rest of state". In Wake, Durham, Orange, Mecklenburg and Gaston Counties, a profile was created based on a morning traffic peak, an afternoon traffic peak, and an offpeak for the remainder of the day. In Wake, Durham, and Orange Counties the morning peak covered the period from 6 am   10 am, and the afternoon peak from 4 pm   8 pm. In Mecklenburg and Gaston Counties the morning peak covered the period from 6 am   9 am, and the afternoon peak covered the period from 4 pm   7 pm. These assumptions were provided by the Metropolitan Planning Organizations ( MPOs) in each of the areas. For the rest of the state, NCDAQ chose to use the Wake County speed profile developed in 1998. This was assumed to be a conservative estimate of speeds in areas that do not have a travel demand model.

Table 5.5 1 provides a summary of the speeds used in this episode run.

Table 5.5 1: 1996 Speed Assumptions for Mobil Model Wake, Durham, Orange Counties ( based on 1995 speeds)

Road Type Morning Peak Afternoon Peak Offpeak Urban Interstate 55 55 55 Urban Freeway 48 47 54 Urban Other P. Art 38 39 44 Urban Minor Art 40 40 43 Urban Collector 36 36 36 Urban Local 36 36 37 Rural Interstate 56 59 64 Rural Other P. Art 53 52 57 Triad Early Action Compact Ozone Action Plan Appendix B Page 42 March 31, 2004 Wake, Durham, Orange Counties ( based on 1995 speeds)

Rural Minor Art 48 47 50 Rural Major Coll 46 46 46 Rural Minor Coll 43 43 43 Rural Local 44 44 44 Greensboro ( based on 1994 speeds)

Road Type Speed Urban Interstate 41 Urban Freeway 46 Urban Other P. Art 27 Urban Minor Art 30 Urban Collector 31 Urban Local 33 Rural Interstate 56 Rural Other P. Art 53 Rural Minor Art 41 Rural Major Coll 44 Rural Minor Coll 44 Rural Local 44 Winston Salem ( based on 1994 speeds)

Road Type Speed Urban Interstate 55 Urban Freeway 48 Urban Other P. Art 29 Urban Minor Art 22 Urban Collector 29 Urban Local 24 Rural Interstate 55 Rural Other P. Art 55 Rural Minor Art 44 Rural Major Coll 41 Rural Minor Coll 39 Triad Early Action Compact Ozone Action Plan Appendix B Page 43 March 31, 2004 Winston Salem ( based on 1994 speeds)

Road Type Speed Rural Local 26 Mecklenburg and Gaston Road Type Morning Peak Afternoon Peak Offpeak Urban Interstate 55 55 55 Urban Freeway 48 47 54 Urban Other P. Art 38 39 44 Urban Minor Art 40 40 43 Urban Collector 36 36 36 Urban Local 36 36 37 Rural Interstate 56 59 64 Rural Other P. Art 53 52 57 Rural Minor Art 48 47 50 Rural Major Coll 46 46 46 Rural Minor Coll 43 43 43 Rural Local 44 44 44 Rest of State Road Type Morning Peak Afternoon Peak Offpeak Urban Interstate 60 61 63 Urban Freeway 55 59 61 Urban Other P. Art 34 35 32 Urban Minor Art 34 35 34 Urban Collector 35 34 33 Urban Local 30 37 37 Rural Interstate 49 62 67 Rural Other P. Art 38 41 42 Rural Minor Art 49 50 53 Rural Major Coll 32 46 46 Rural Minor Coll 33 41 44 Rural Local 42 45 42 Triad Early Action Compact Ozone Action Plan Appendix B Page 44 March 31, 2004 5.5.2 VEHICLE AGE DISTRIBUTION The vehicle age distribution comes from annual registration data from the NCDOT. NCDOT has provided registration data specific to the area. For this analysis, the data was from 2000. NCDOT provides the data by vehicle type; however, these types do not match the EPA MOBILE types. Therefore, the data is manipulated to match the input requirements as follows:

  NCDOT provides at least 25 years for all vehicle types, however MOBILE5 only recognizes 12 years for motorcycles. Therefore, the first 13 years are combined into one number.   If more than 25 years are provided, the early years are combined and included in the 25th model year.   NCDOT does record model years beyond the year of the report, for this set of data, 2001 model year was added to the 2000 model year information.   The same registration distribution by age must be entered for Light Duty Gasoline Vehicles ( LDGV), Light Duty Diesel Vehicles ( LDDV), and for Light Duty Gasoline Trucks 1 and 2 ( LDGT1 and LDGT2) according to the MOBILE5 User's Guide.

Then using the MOBILE6.2 utility provided by EPA the vehicle types were distributed across the 16 types in MOBILE6.2. A separate age distribution was created for each of the urban areas and for the rest of the state ( see Appendix B).

5.5.3 VEHICLE MIX ASSUMPTIONS For all of North Carolina, vehicle mix has incorporated the increase in sales of sport utility vehicles and minivans for all years of evaluation.

To calculate the vehicle mix to account for the large percentage of sport utility vehicles and minivans being purchased, NCDAQ used the following documentation from EPA: Fleet Characterization Data for MOBILE6: Development and Use of Age Distributions, Average Annual Mileage Accumulation Rates, and Projected Vehicle Counts for Use in MOBILE6 ( EPA420 P 99 011). This document includes a breakdown by year from 1983 to 2050 of the number of light duty vehicles ( according to MOBILE6 five vehicle types) on the roads on a national basis. NCDAQ used this data and combined vehicle types to reflect the three MOBILE5 light duty vehicle types. These calculated values for LDGT1 and LDGT2 are used for all road types. No changes were made to this file for this modeling effort because of the way in which the SMOKE model has incorporated MOBILE6.2. Table 5.5 2 provides the vehicle mix for North Carolina. Triad Early Action Compact Ozone Action Plan Appendix B Page 45 March 31, 2004 Table 5.5 2: 1996 North Carolina Vehicle Mix Rural LDGV LDGT1 LDGT2 HDGV LDDV LDDT HDDV MC Interstate( 0.001) 0.458 0.174 0.062 0.031 0.002 0.002 0.266 0.005 Oth Prin Art(+ 0.001) 0.557 0.211 0.075 0.04 0.002 0.002 0.109 0.004 Minor Ar( 0.001) 0.571 0.219 0.078 0.045 0.003 0.003 0.076 0.005 Major Col (+ 0.001) 0.591 0.225 0.08 0.044 0.002 0.002 0.052 0.004 Minor Col 0.591 0.225 0.08 0.042 0.002 0.002 0.053 0.005 local 0.589 0.227 0.081 0.049 0.003 0.003 0.042 0.006 Urban LDGV LDGT1 LDGT2 HDGV LDDV LDDT HDDV MC Interstate ( 0.002) 0.534 0.201 0.072 0.033 0.002 0.002 0.152 0.004 Oth Freeway 0.583 0.218 0.078 0.035 0.002 0.002 0.079 0.003 Oth Prin Art(+ 0.001) 0.6 0.224 0.08 0.036 0.002 0.002 0.053 0.003 Minor Art( 0.001) 0.614 0.229 0.082 0.035 0.002 0.002 0.032 0.004 Collectors( 0.001) 0.622 0.231 0.082 0.033 0.002 0.002 0.025 0.003 local (+ 0.001) 0.602 0.228 0.081 0.041 0.002 0.002 0.038 0.006 HDGV   Heavy Duty Gasoline Vehicles, LDDT   Light Duty Diesel Trucks, HDDV   Heavy Duty Diesel Vehicles, MC  Motorcycles 5.5.4 TEMPERATURE ASSUMPTIONS Temperatures are extracted from the MM5 meteorological model files.

5.5.5 VEHICLE INSPECTION AND MAINTENANCE PROGRAM ASSUMPTIONS In the early 1990' s, North Carolina adopted emissions inspection requirements for vehicles in 9 urban counties. This program tests emissions at idle for 1975 and newer gasoline powered light duty vehicles. The program is a basic, decentralized tailpipe test for Hydrocarbon ( HC) and CO only. The waiver rates are consistent with the SIP. However, the compliance rates have been changed to more accurately reflect what is happening at the stations. Compliance rates have been changed from 98 percent in the SIP to 95 percent. In addition, the inspection stations are required to administer an anti tampering check to ensure that emissions control equipment on any vehicle 1968 and newer has not been altered. Triad Early Action Compact Ozone Action Plan Appendix B Page 46 March 31, 2004 5.5.6 RVP ASSUMPTIONS Reid vapor pressure ( RVP) reflects a gasoline's volatility, so as a control measure North Carolina has adopted the Phase II RVP of 7.8 psi in the 1 hour ozone maintenance counties.

The emissions summary for the 1996 episodes for the counties in the Triad EAC area is listed in Table 5.5 4. These emissions represent a typical weekday, Thursday's ( June 20th), are in tons per day.

Table 5.5 4 Highway Mobile Emissions County CO NOx VOC Alamance 107.43 14.92 9.43 Caswell 18.33 1.95 1.65 Davidson 150.84 27.56 12.92 Davie 37.20 8.36 3.07 Forsyth 207.45 32.63 20.60 Guilford 274.51 44.36 27.54 Randolph 122.08 17.26 10.75 Rockingham 77.73 7.94 7.21 Stokes 28.49 2.87 2.57 Surry 78.33 12.38 6.98 Yadkin 39.27 7.03 3.44 Total 1141.65 177.25 106.14 5.6 Biogenic Emission Sources Biogenic emissions will be prepared with the SMOKE BEIS3 ( Biogenic Emission Inventory System version3) preprocessor. SMOKE BEIS3 is basically the Urban Airshed Model ( UAM) BEIS3 model but also includes modifications to use Meteorological Model version 5 ( MM5) data, gridded land use data, and one important science update. The emission factors that are used in SMOKE BEIS3 are the same as the emission factors in UAM BEIS3.

The emission rates within SMOKE BEIS3 are adjusted for environmental conditions prevailing during the episode days with meteorological data supplied by the MM5 model. The gridded data used from MM5 include the estimated temperature at 10 meters above the surface and shortwave radiation reaching the surface. Ten meters temperatures will be used instead of the ground temperatures because it is believed that 10 meters above the surface is a good approximation of the average canopy height. The use of 10 meters temperatures was discussed with and approved by the USEPA Office of Research and Development ( ORD). Triad Early Action Compact Ozone Action Plan Appendix B Page 47 March 31, 2004 The gridded land use data has been obtained from Alpine Geophysics at the 4 km resolution for the entire domain. The basis for the gridded data is the county land use data in the Biogenic Emissions Landcover Database version 3 ( BELD3) provided by the USEPA. A separate land classification scheme, based upon satellite ( AVHRR, 1 km spatial resolution) and census information, aided in defining the forest, agriculture and urban portions of each county. The 12 km and 36 km domains will be created by aggregating the 4 km resolution data up to the respective grid sizes.

The emissions summary in for the 1996 episodes for the counties in the Triad EAC area is listed in Table 5.6 1. These emissions represent a normalized emission and are in tons per day.

Table 5.6 1 Biogenic Emissions County NOx VOC Alamance 0.4 73.9 Caswell 0.3 57.2 Davidson 0.4 78.6 Davie 0.4 55.4 Forsyth 0.4 59.3 Guildford 0.5 78.7 Randolph 0.5 109.1 Rockingham 0.4 64.3 Stokes 0.4 64.1 Surry 0.5 71.2 Yadkin 0.4 58.1 Total 4.6 769.9 Triad Early Action Compact Ozone Action Plan Appendix B Page 48 March 31, 2004 Section 6  MODELING STATUS 6.1 Status of Current Modeling NCDAQ realized that the May 31, 2003 date for completing the base case model evaluation was not realistic due to the issues described in Section 6.2 below. Sheila Holman sent a letter to Kay Prince requesting an adjustment to the modeling schedule due to these issues. Ms. Holman's letter and Ms. Prince's response are included in Appendix C. NCDAQ continues to believe that completing the four 2007 base year modeling runs is achievable by August 29, 2003.

6.2 Issues Being Encountered There have been a number of issues encountered during this modeling effort. The first was the integration of MOBILE6.2 into SMOKE. It is a requirement of the EAC that MOBILE6.2 be used to estimate the mobile emissions and if transportation conformity is ever needed in the EAC areas, it will be based on the emission estimates from this modeling effort. It took much longer than anticipated to get the integration completed.

Another issue was porting SMOKEv1.5 to the NCDAQ HP UNIX workstation. Compiling on the HP was not very straight forward and actually turned up some errors in the SMOKEv1.5 code. It took several weeks before the code was completely compiled and tested on the HP workstation and was ready for the NCDAQ emissions staff to use.

The next issue encountered dealt with the installation and use of MIMS. MIMS is a gui interface that aids the user in choosing the files that will be used in SMOKE to process the emissions. Since most of the NCDAQ emissions staff is not very familiar with the UNIX environment, it was believed that the MIMS interface would aid in processing the emissions. NCDAQ was never able to get MIMS to work on their system and therefore had to use scripts to process the emissions.

Another issue was the discovery of errors in the mobile and point source emissions during the quality assurance ( QA) of the emissions data. For the mobile inventory, VMT was inadvertently left off for two of the urban counties, Guilford and Forsyth Counties. For the point source inventory, it was discovered that stack data for some of the utilities did not read in correctly and default stack parameters were used. This would result in the emissions being dumped into the lower layer of the model. These errors resulted in the emissions having to be reprocessed through SMOKE and re merged with the other data.

6.3 Geographic Area Needing Further Controls At this point in the project, NCDAQ is unable to identify the geographic area that will need controls beyond what is already in North Carolina's rules. The controls that will be included in Triad Early Action Compact Ozone Action Plan Appendix B Page 49 March 31, 2004 the base 2007 emissions inventory are the NOx SIP Call, a NOx Inspection and Maintenance ( I/ M) program that will cover 48 counties in North Carolina and the North Carolina Clean Smokestacks Act that requires year round controls on the major utilities in North Carolina.

By the December 2003 Progress Report, NCDAQ should be able to provide modeling results that show where additional controls are needed over what geographic area.