Attachment to :

Technical Support Document For the Modeling and Weight of Evidence (WOE) Portions of the Document Entitled “Cecil County, Maryland 8 - Hour Ozone State Implementation Plan and Base Year Inventory SIP Revision: 07 - 05, June 15, 2007 Technical Support Document for the Modeling and Weight of Evidence (WOE) Portions of the State of Delaware’s Ozone State Implementation Plan (SIP) Entitled “Delaware State Implementation Plan for Attainment of the 8 - Hour Ozone National Ambient Air Quality Standard Reasonable Further Progress and Attainment Demonstration, June 2007” Technical Support Document for the Modeling and Weight of Evidence (WOE) Portions of the Commonwealth of Pennsylvania’s Ozone State Implementation Plan (SIP) Entitled “Commonwealth of Pennsylvania Department of Environmental Protection State Implementation Plan Revision: Attainment Plan and Base Year Inventory Bucks, Chester, Delaware, Montgomery and Philadelphia Counties located in the Philadelphia - Wilmington - Atlantic City, PA -NJ - DE Eight - Hour Ozone Nonattainment Area July 2007” SCOPE: This attachment supplies some estimate s of additional reductions anticipate d to occur between 2007 and 2009 and between 2008 and 2009 . I. Estimation of emission reductions from fleet turnover between 20 07 and 2009. A. Background: A ty pical State SIP submittal includes the 2002 base year emissions, 2008 projected controlled emissions in the RFP plan and 2009 projected controlled emissions in the attainment demonstration. The expected decrease or redu ction in emissions between 2008 and 2009 can be determined directly . One way to estimate the emissions reductions for 2007 to 2009 would be to double the reduction from 2008 to 2009. This method assumes the change in emissions is linear over time. Mob ile Source Estimation Methodologies: Mobile source emissions are estimated for future years using the MOBILE6.2 emission factor models for on - road (or highway) sources and the NONROAD model for off - road or nonroad sources. On - road mobile source emissions are ty pically developed using the MOBILE6.2 model to generate the emission factors and a travel demand model (TDM) is used to generate the vehicle miles travelled (VMT) which is the activity level. Conceptually , the on - road mobile source emissions are de termined by multiplying the VMT in miles by the emission factor (EF) in grams per mile: Emissions = EF ∙ VMT.2

Because the EF generated by MOBILE6.2 is a function of speed, vehicle ty pe, vehicle age and other factors, the overall emissions are a summation of many VMT values representing each link or roadway class multiplied by many emission factors corres ponding to the vehicle mix and speed on that roadway class . Emissions = ∑ ( EF ∙ VMT ) B. On - Road Mobile Source Emissions Changes Over Time: In future years the on - road mobile source emissions are affected b y ch anges in VMT and changes in emission factors. The TDM projections tend predict VMT will increase over time while speeds may or may not change generall y decreasing (due to congestion). The VMT/speed changes will cause future year projection VMT to be higher resulting in higher emissions than if VMT remained constant. The EF values decrease dramaticall y because the future year fleet is predicted to be made up of a higher percentage of newer vehicles then the 2002 fleet (motor vehicles must be replaced over time as they wear out, corrode, are involved in collisions, etc.). These newer vehicles meet the more stringent standards such as the Tier 2 standards which started only in model year 2004 and the heavy- duty standards which took effect with the model ye ar 2002 standards with more stringent standards applying to model year 2007 and newer vehicle. The effect of the decreasing EFs is a net overall decrease in projected on - road vehicle emissions in future years (as evinced b y the much lower 2009 emission estimates). Due to the competing eff ects of VMT (tending to increase future year emissions) and of the EF value declines (tending to decrease future year emissions) one should not expect the change over time to be linear between 2002 and 2009. Simple examination of plotting the emissions provided in the plan will show that the emissions change over time is non - linear. Consider for example the on - road NOx emissions for the Penns ylvania portion of the Philadelphia area. On - road NOx emissions for the Penns ylvania (in tons per day (TPD)) Ye ar 2002 2008 2009 Emissions of Nox (TPD) 184.66 108.78 101.6 Plotted graphically one sees this is the case:3

If one linearly interpolates a 2008 value between 2002 and 2009 one gets: 113.457 = 184.66

– [(101.60

– 184. 66)/7 ∙ 5 ] , which is more than the value in the SIP. This suggests that linear interpolation between 2002 and 2009 will over estimate 2007 emissions levels. C. Nonroad Mobile Source Emissions Changes Over Time: The nonroad mobile source emissions are determined conceptually in the same manner

– EFS are multiplied by an activity levels and these products for all over all nonroad engine types are summed. The NONROAD model packages this process within one model. The NONROAD model will predict higher a ctivity levels for future years but lower EF values as the nonroad fleet turns over. Generall y, the net effect is an overall decrease in nonroad mobile sources after the 2002 base year. Due to the competing effects of increased projected activity levels (tending to increase future ye ar emissions) and of the EF value declines (tending to decrease future year emissions) one should not expect the change over time to be linear between 2002 and 2009. Simple examination of plotting the emissions provided in the plan will show that the emissions change over time is non - linear. Consider for example the non - road NOx emissions for the Penns ylvania portion of the Philadelphia area. Non - road NOx emissions (in TPD) Year 2002 2008 2009 Emissions of Nox 70.95 62 .67 61.13 PA Portion of Philadelphia A rea On - Road NOx

0 50 100 150 200

2000 2002 2004 2006 2008 2010 YearNOx (TPD)4

If one linearly interpolates a 2008 value between 2002 and 2009 one gets: 62.53 = 70.95

– [(61.13

– 70.95)/7 ∙ 5 ] , which is less than the value in the SIP. (The non - linearity is not as pronounced graphically for the nonroad case as for the o n - road case.) D. Conclusion: Linear Interpolation between 2002 and 2009 may not be the best method to estimate 2007 mobile source emissions. E. Non - Linear Interpolation: Because there are three data points (except in the case for Delaware) 1 one can fit a quadratic equation of the form AY2 + By + C = E yyyy where: A, B and C are constants, Y is the number of years after 2002 (hence Y = 0 for 2002, 5 for 2007, 6 for 2008 and 7 for 2009) and E yyyy is the year of emissions (yyyy = 2002, 2007, etc.). Because Y = 0 for 2002, C = E 2002 the base year level. The formulae used to calculate A and B from E 2002 , the base year emissions, E 2008 ,the 2008 projected emissions and E 2009 , the 2009 projected emissions are derived in Section IV below. Using the coefficients derived for each State and source sector, a quadratic equation was used to estimate the 2007 on - road mobile source and 2007 nonroad mobile source NOx emissions for each state (with the exception of Delaware’s 2007 nonroad NOx emissions which w ere a linear interpolation between 2002 and 2009). F. Summary of Interpolation Results: Summary of Estimated 2007 to 2009 Nonroad Mobile Source NOx Reductions DE MD NJ PA Total A * - 0.00619 0.0023809 - 0.022857

1 Delaware’s RFP plan relied upon a demonstration that sufficient VOC reductions would be achieved by 2008 to meet the 15% RFP requirement. Therefore, Delaware’s RFP plan did not need to (nor did it) include 2008 projections of NOx emissions for the source sectors of point, area and nonroad mobile sources. Delaware’s RFP plan did include 2008 projections of VOC emissions for all source sectors. Delaware did include 2008 NOx emissions projections for on - road sources to set NOx motor vehicle emissions budgets (MVEBs) for 2008 in addition to 2008 VOC MVEBs. For this analysis, a linear interpolation was used to estimate nonroad mobile source NOx emissions in Dela ware for 2007.5

B * 0.020476 - 1.230952 - 1.242857 C * 2.97 70.6 70.95 Estimated 2007 Nonroad NOx = 25 ∙ A + 5 ∙ B + C 50.5* 2.92 64.5 64.16 Projected 2009 On - Road NOx from the SIP Submittal 49.59 2.81 62.1 61.13 Reductions 2007 to 2009 0.91 0.11 2.40 3.03 6.46 Note : * Li near Interpolation used: E2007 = E2002 - (E2009 - E2002)/7 * 5 Summary of E stimated 2007 to 2009 On - Road Mobile Source NOx Reductions DE MD NJ PA Total A 0.07142857 0.10326190 0.859523 0.780952 B - 4.6185714 - 1.6640476 - 16.5738 - 17.3323 C 69.03 14.22 179.8 184.66 Estimated 2007 Nonroad NOx = 25 ∙ A + 5 ∙ B + C 47.72 8.47 118.42 117.52 Projected 2009 On - Road NOx from the SIP Submittal 40.2 7.60 105.9 101.60 Reductions 2007 to 2009 7.52 0.87 12.52 15.92 36.83 Summary of Estimated 2007 to 2009 Nonroad Mobile Source VOC Reductions DE MD NJ PA Total A - 0.0021429 0.02 71428 - 0.107142 - 0.003809 B - 0.8121429 - 0.352857 - 2.507142 - 2.680476 C 26.77 8.37 99.00 79.06 Estimated 2007 Nonroad NOx = 25 ∙ A + 5 ∙ B + C 22.66 7.28 83.78 65.56 Projected 2009 On - Road NOx from the SIP Submittal 20.98 7.23 76.2 60.11 Reductions 2007 to 2009 1.68 0.05 7.59 5.45 14.77 Summary of Estimated 2007 to 2009 On - Road Mobile Source VOC Reductions DE MD NJ PA Total A 0.1152381 0.0278571 0.538095 0.556904 B - 2.448095 - 0.452142 - 10.3952 - 9.61976 C 32.38 4.00 91.8 98.76 Estimated 2007 Nonroad NOx = 25 ∙ A + 5 ∙ B + C 23.02 2.44 53.28 64.58 Projected 2009 On - Road NOx from the SIP Submittal 20.89 2.29 45.4 58.7 1 Reductions 2007 to 2009 2.13 0.24 7.88 5.87 16.116

The expected magnitude of reductions remaining is simply the difference between the 2007 estimates and the 2009 projections provided in the State submittals. G. Data and computations: The emissions estimates and computations are in the attached printouts of the worksheet titled “ Mobile Emissions Estimates ” in a Microsoft® Excel 2003 spreadsheet, a cop y of which is included in the docket for this action. H. Sources of Data for the Shreadsheets: Tables 3 - 3, 3 - 4, Section 5.5, Tables 6 - 4, 6 - 10 and 6 - 11 from “ Final Submittal, Delaware State Implementation Plan For Attainment Of The 8 - Hour Ozone National Ambient Air Quality Standard, Reasonable Further Progress and Attainment Demonstration, Submitted To U.S. Environmental Protection A gency , By Delaware Department of Natural Resources and Environmental Control, ” June 2007. Tables 3 - 1, 4 - 3 and 4 - 4 to “ Cecil County , Maryland 8 - Hour Ozone State Implementation Plan and Base Year Inventory , ” SIP Revision: 0 7 - 05, June 15, 2007. Tables 4 - 1, 4 - 2, 4 - 7 to “ Commonwealth of Pennsylvania, Department of Environmental Protection, State Implementation Plan Revision: Attainment Demonstration and Base Year Inventory , Bucks, Chester, Delaware, Montgomery and Philadelphi a Counties located in the Philadelphia - Wilmington - Atlantic City , PA -NJ - DE Eight - Hour Ozone Nonattainment Area, ” August 2007 . Table 6.3: Projected Emissions and Control Measure Benefits New Jersey Portion of Southern New Jersey

/Philadelphia Nonattainment Area in Chapter 6.0 “ Reasonable Further Progress (RFP) ” of “State Implementation Plan (SIP) Revision for the Attainment and Maintenance of the Ozone National Ambient Air Quality Standard 8 - Hour Ozone Attainment Demonstration, Final, ” dated October 29, 2007 . Available at http://www.nj.gov/dep/baqp/8hrsip/8hrsip.html#final (last checked Thursday , December 11, 2008) and at http://www.regulations.gov , docket EPA - R02 - OAR - 2008 - 0497 . II. Remaining Reductions from Delaware’s Multi Pollutant Regulation : A. T he Multi Pollutant Regulation and Requirements The implementing regulations for Delaware’s Multi Pollutant Regulation are found in Regulation No. 1146, “ Electric Generating Unit (EGU) Multi - Pollutant Regulation ” which was approved into the Maryland SIP o n August 28 , 2008 ( 73 FR 50723 ). 2

2 A copy of Regulation No. 1146: Electric Generating Unit (EGU) Multi - Pollutant Regulation is attached. The Delaware SIP can be viewed on line at http://yosemite.epa.gov/r3/r3sips.nsf/SIPIndex!OpenForm (last accessed December 12, 2008).7

The relevant provisions of Regulation No. 1146 are as follows: Regulation .01 (COMAR 26.11.27.01) provides the following pertinent definitions in sections A and B as follows: Section 2.0 “Applicability” States: This regulation applies to coal - fired and residual oil - fired electric generating units located in Delaware with a nameplate capacity rating of 25 MW or greater that commenced operation on or before the effective date of this regulation. Section 3.0 “Definitio ns” conatins the following definitions: “Unit” means, for the purposes of this regulation, a stationary , fossil - fuel - fired boiler supplying all or part of its output to an electric generating device. Section 4.0 “NO x Emissions Limitations ” sets the follo wing requirments for affected units: 4.1 From May 1, 2009 through December 31, 2011, no unit subject to this regulation shall emit NOx at a rate exceeding 0.15 lb/MMBTU. 4.1.1 Compliance with the requirements of paragraph 4.1 of this section shall be demo nstrated on a rolling 24 - hour average basis. In Table 6 - 1 “Delaware 2009 VOC and NOx Emission Projections (TPD) for Electric Generating Units (EGUs)” Delaware identified eight units affected by regulation 1146. These are Facility Name Unit Description City Of Dover - McKee Run Generating Sta Boiler #3 Conectiv Delmarva Generation - Edge Moor Boiler #3 Conectiv Delmarva Generation - Edge Moor Boiler # 4 Conectiv Delmarva Generation - Edge Moor Boiler # 5 Indian River Generating Station Boiler #1 Indian River Generating Station Boiler # 2 Indian River Generating Station Boiler # 3 Indian River Generating Station Boiler # 4 B. Actual 2007 Emissions and Preliminary 2008 Emissions Data For EPA’s review, the 2007 actual emissions levels at the affected units are known. This data is available at the EPA’s “ Clean Air Markets - Data and Maps ” web portal (http://camddataandmaps.epa.gov/gdm/index.cfm) maintained by EPA’s Clean Air Markets Divisio n (CAMD). Data for the eight affected units was downloaded on December 12, 2009. The data downloaded included information identifying the facility and units, NOx mass emissions (in tons) for each season , and the heat input for the unit (in mmBTU) for eac h season .8

EPA obtained the data for two seasons : the regulatory ozone season (May 1 st through September 30 th ) and the peak ozone season (June 1 st through August 31 st). For the full ozone season, the sum of the actual emissions for the regulatory ozone s eason was divided b y 153 days in the period to obtain an average daily actual emissions amount for the 2007 regulatory ozone season . For the peak ozone season the average dail y emissions was divided by 92 days in the period to obtain an average daily actu al emissions amount for the 2007 peak ozone season. To estimate the effect of regulation 1146, the heat input for each season was multiplied by 0.15 pounds NOx/mmBTU to estimate the levels of NOx emission s in tons for each season that would have been allo wed if Regulation 1148 had been in effect. The estimated allowable emissions for each unit were subtracted from the actual emissions for each season to obtain the estimated reductions over the period. The estimated reduction each season was divided b y the number of day s in each season (153 for the regulatory ozone season and 92 for the peak ozone season) to obtain an average reduction in tons per day for that season. C . Summary of results 2007 to 2009: Regulation No. 1146, “ Electric Generating Unit (EGU) Multi - Pollutant Regulation ” 2007 - 2009 Full Regulatory Ozone Season Peak ozone Season Seasonal 2007 NOx Emissions 3 9 94.985 3491.336 Seasonal 2007 NOx Emissions at 0.15 lbs NOx/mmBTU Heat Input 1995.103 1742.436 Estimated seasonal reductions av ailable 1999.882 1748.900 Estimated daily Reductions Between 2007 and 2009 13.071 19.010 D . Summary of results 2008 to 2009: A similar process to that described in section II. C above was applied to the preliminary 2008 emissions date availab le at the “Clean Air Markets - Data and Maps ” web portal which was downloaded December 12, 2008. The results are: Regulation No. 1146, “ Electric Generating Unit (EGU) Multi - Pollutant Regulation ” 2008 - 2009 Full Regulatory Ozone Season Peak ozone Season Seasonal 2007 NOx Emissions 3008.733 2075.988 Seasonal 2007 NOx Emissions at 0.15 lbs NOx/mmBTU Heat Input 1519.851 1042.854 Estimated seasonal reductions available 1437.282 1033.1349

Estimated daily Reductions Between 2007 and 2009 9.394 11 .230 E . Data and computations: The CAMD data and computations are in the attached printouts of the worksheets titled “ 2008 Full Ozone Season ,” “ 2008 Peak Ozone Season ,” “ 2007 Ozone Full Season ,” and “ 2007 Peak Ozone Season ” in a Microsoft® Excel 2003 s preadsheet, a cop y o f which is included in the docket for this action. III. Other Regulations taking Effect after January 1, 2007. A. NOx Measures: New Jersey identified several additional measures scheduled to take effect after January 1, 2007. The se include the Refinery Enforcement Initiative , and Certain Categories of I CI Boilers for which New Jersey projected 0.3 tpd and 2.0 tpd in NOx emissions reductions, respectivel y , commencing in 2009 . See Table 6.3 “Projected Emissions and Control Measure Benefits New Jersey Portion of Southern New Jersey /Philadelphia Nonattainment Area” in Chapter 6.0 “ Reasonable Further Progress (RFP) ” of “State Implementation Plan (SIP) Revision for the Attainment and Maintenance of the Ozone National Ambient Air Quality S tandard 8 - Hour Ozone Attainment Demonstration, Final,” dated October 29, 2007, of New Jersey’s SIP submittal. Additionally, New Jersey ’s NOx RACT Rule 2006 (which includes distributed generation) is discussed in section 4.3.1.4.3 in Chapter 4.0 Control Measures of the New Jersey SIP submittal. This rule has a number of compliance dates in 2007. See 72 FR 11812, March 14, 2007 and 72 FR 41626 , July 31, 2007 . New Jersey estimated reductions in NOx emissions of 2.1 TPD. See Table 6.3 “Projected Emissi ons and Control Measure Benefits New Jersey Portion of Southern New Jersey /Philadelphia Nonattainment Area” of New Jersey ’s SIP submittal. B. VOC Measures: The plans for the Philadelphia area identified VOC control regulations for which the plan projec ted no reductions in 2008 but did project reductions for 2009. These three regulations are summarized in the table below: Estimate of VOPC Reductions From Stationary Sources 2007 - 2009 State Measure Reductions Source MD OTC - Consumer Products

Phase 2 0.02 Table 6.1: Control Measures Summary 3 MD OTC - PFC Phase 1 0.06 Ditto 3 From “ Cecil County, Maryland 8 - Hour Ozone State Implementation Plan and Base Year Inventory, ” SIP Revision: 07 - 05, June 15, 2007.10

MD OTC - PFC Phase 2 0.03 Ditto MD OTC

– In dustrial

Adhesives 0.10 Ditto NJ EPA MACT Standards 1.1 Table 6.3: Projected Emissions and Control Measure Benefits New Jer sey Portion of Southern New Jersey /Philadelphia Nonattainment Area4 NJ Refinery Enforcement

Initiative 0.9 Ditto NJ Consumer Products 2009

Amendments 0.4 Ditto NJ Adhesives and Sealants 2.2 Ditto NJ Asphalt Paving (Cutback

and Emulsified Asphalt) 1.5 Ditto NJ Portable Fuel Containers

(2005 + 2009) 0.8 Ditto DE Regulation 1124 Section

46, Crude Oil Lightering Operations 2.58 Section 5.1.1 A. Crude Oil Lightering Operations 5 Totals ................ 9.69 The portable fuel containers (PFC ) rules are projected to achieve vastl y (in a relative sense) more reductions in 2009 than in 2008. Some of these reductions will only offset growth in activity levels, but for this anal ys is EPA will assume all reductions from 2008 to 2009 are net of growth as the amounts are small in relation to the reductions from 2002 through 2009. The PFC rules achieve additional reductions after the implementation date as new containers meeting the PFC rule replace older ones. The differences that could be readil y discerned from the plans are: Cecil County Maryland: For the Phase I PFC rule, the State projected 0.26 tons per day reduction in 2008 and 0.32 for 2009 for difference of 0.06. The M<Maryland Phase 2 PFC rule is an additional rule. New Jersey Portion of Southern New Jersey /Philadelphia Nonattainment Area: The State projected 1.3 tons per day reduction in 2008 and 2.1 for 2009 for difference of 0.8 tons per day . IV . Derivation of A, B and C:

4 From Chapter 6.0 “ Reasonable Further Progress (RFP) ” of “State Implementation Plan (SIP) Revision for the Attainment and Maintenance of the Ozone National Ambient Air Quality Standard 8 - Hour Ozone Attainment Demonstration, Final,” dated October 29, 2007. 5 “Final Submittal, Delaware State Implementation Plan For Attainment Of The 8 - Hour Ozone National Ambient Air Quality Standard, Reasonable Further Progress and Attainment Demonstration, Submitted To U.S. Environmental Protection Agency, By Dela ware Department of Natural Resources and Environmental Contro l,” June 2007 .11

Given A ∙Y2 + B ∙Y + C = E yyyy where: A, B and C are constants, Y is the number of years after 2002 (hence Y = 0 for 2002, 5 for 2007, 6 for 2008 and 7 for 2009) and E yyyy is the year of emissions (yyyy = 2002, 2007, etc.). Now, E2, E8 and E9 are known. For the 2002 year, E2, Y is zero by definition. Thus, C = E 2002 because A ∙ 0 2 + B ∙ 0 + C = E 2002. For 2008, Y = 6 and A ∙6 2 + B ∙6 + C = E 2008 . [Eqn 1] For 2009 Y = 7, and , A ∙7 2 + B ∙7 + C = E 2009 . [Eqn 2] Multiply Eqn 1 by 7 and Eqn 2 by 6 to get: 7 ∙ A ∙6 2 + B ∙ 42 + 7 ∙ C = 7 ∙ E 2008 . [Eqn 1A] 6 ∙ A ∙7 2 + B ∙ 42 + 6 ∙ C = 6 ∙ E 2009 . [Eqn 2A] Subtract Eqn 1B from Eqn 1A to get: 7 ∙ A ∙6 2 - 6 ∙ A ∙7 2 + + 7 ∙ C - 6 ∙ C = 7 ∙ E 2008 - 6 ∙ E 2009 [Eqn 3] A ∙ (7 ∙ 6 2 - 6 A ∙7 2 ) + C = 7 ∙ E 2008 - 6 ∙ E 2009 Solving for A: A = (7 ∙ E 2008 - 6 ∙ E 2009 – C) (7 ∙ 6 2 - 6 A ∙7 2 ) Now, C = E 2002 yi elding: A = (7 ∙ E 2008 - 6 ∙ E 2009 – E 2002 ) [Eqn 4] (7 ∙ 6 2 - 6 A ∙7 2 ) Taking equation Eqn 2A, A ∙6 2 + B ∙ 6 + C = E 2008 , knowing C = E 2002 and solving for B yields:12

B ∙ 6 = E 2008 - A ∙6 2 - E 2002 B= (E 2008 - A ∙6 2 - E 2002 ) where Eqn 4 is used to calculate A. [Eqn 5]

613

PRI NOUT OF WORKSHEETS (18 Pages): “ Mobile Emissions Estimates ,” “ 2008 Full Ozone Season ,” “ 2008 Peak Ozone Season ,” “ 2007 Ozone Full Season ,” and “ 2007 Peak Ozone Season ” in a Microsoft® Excel 2003 spreadsheet, a copy of which is included in the docket for this action.