APPENDIX A5$_{ }$ A5.2.2.2  Emission Factors  A5.2.3  Snowmelters  Source : Emissions and Dispersion Modeling System (EDMS) User’s Manual,  FAA-AEE-07-01 (Rev. 10 – 06/07/13), June 2013,  http://www.faa.gov/about/office_org/headquarters_offices/apl/research/models/edms_model/media/EDMS_5.1.4_User_Manual.p  df; and Jagielski, Kurt D., and Robert J. O'Brien,  Calculation Methods for Criteria Air Pollutant Emission Inventories , July 1994.  Notes:  $^{1 }$Emission factors are expressed in pounds per thousand gallons for fuel and pounds per million cubic feet for natural gas.  $^{2 }$(S) signifies the fuel sulfur content, expressed as weight percent sulfur, which is multiplied by the coefficient given to obtain  the emission factor for SO$_{2}$.  Snowmelters at airports are used to remove snow from airfield surfaces. They  are portable and  stationary sources that are typically powered by gasoline or diesel -fuel or natural gas. Emissions  are dependent on type of fuel and the amount of fuel being burned over the time period be ing  analyzed.  The uncontrolled emission factors for  Equation A5-4  ( Total Pollutant Emissions for Generators  – U.S. Air Force’s Method ) for generators powered by reciprocating engines are given in  Table  A5-1  ( Uncontrolled Emission Factors for Generators ). These emission factors are also default values used in EDMS/AEDT. Note that for SO$_{2}$, the percent of sulfur in the fuel must be  obtained to calculate the emission factor. The type of fuel and sulfur content should be available  from the fuel supplier and/or the airport operator.  The uncontrolled emission factors for  Equation A5-3  ( Total Pollutant Emissions for Generators  - EPA’s AP-42 Method ) for gasoline and diesel engines are given in  Chapter 3.3,  Gasoline and  Diesel Industrial Engines 22 ,  of EPA’s AP-42. These emission factors can be used for engines that  have a rated power of up to 250 horsepower (hp) for gasoline engines and up to 600 hp for diesel  engines. Diesel engines greater than 600 hp are covered in  Chapter 3.4,  Large Stationary Diesel  and All Stationary Dual-fuel Engines 23 , of EPA’s AP-42.  Table A5-1. Uncontrolled Emission Factors for Generators  Fuel  Emission Factors 1  CO  PM$_{10 }$ NO$_{x }$ SO$_{2 }$ 2  VOC  Distillate Oil (Diesel)  130  32.0  604  141(S)  49.3  Kerosene/Naphtha (Jet Fuel)  102  32.0  469  128(S)  32.1  Gasoline (Mogas)  7,128  6.2  185  123(S)  344  Natural Gas  (pounds/million cubic feet)  430  10.0  3,400  840(S)  82.9  LPG (Propane or Butane)  129  5.0  139  91(S)  83.0  Residual/Crude Oil  102  30.8  469  152(S)  32.1  22 EPA, AP-42, Chapter 3.3,  Gasoline and Diesel Industrial Engines ,  http://www.epa.gov/ttnchie1/ap42/ch03/final/c03s03.pdf.  23 EPA, AP-42, Chapter 3.4,  Large Stationary Diesel and All Stationary Dual-fuel Engines ,  http://www.epa.gov/ttnchie1/ap42/ch03/final/c03s04.pdf.  26$_{ }$