APPENDIX A5$_{ }$ E$_{PM }$= 2 x TH x EF  Where:  E$_{PM }$= total particulate emissions from pile loading and unloading, expressed in pounds.  2 = factor representing number of drops material undergoes; once during loading and once  during unloading.  TH = total throughput of material stored in pile in a given time period, expressed as tons.  EF = emission factor, given as pounds of particulate matter emitted per ton of material  undergoing drop operation.  The data inputs required to estimate  PM emissions during loading and unloading of material  piles and the likely sources of obtaining this information are summarized in  Table A5-10  ( Data  Inputs for Loading and Unloading of Materials ).  Source: Chapter 13.2.4,  Aggregate Handling and Storage Piles , of EPA's AP-42,  http://www.epa.gov/ttnchie1/ap42/ch13/final/c13s0204.pdf.  Data Inputs  Source  Mean Wind Speed  Only one figure for the mean wind speed at the airport is required. This may be obtained  from  the  National  Climatic  Data  Center  at  the  http://www.ncdc.noaa.gov/ or from the weather station on si te. The mean wind speed should be expressed in meters per seconds (m/s).  Material Moisture  Content  This information can be obtained by direct sampling of the piles, or maintenance operator of the pile. If data is unavailable, Chapter 13.2.4,  Aggregate  Handling and Storage Piles, of EPA’s AP -42 provides information on the content of material types by industry. The moisture content of the material of the should be expressed in percentages.  Quantity of Material  Loaded and Unloaded  This information should be obtained from the maintenance operations Because the methodology takes into account both loading and unloading of the pile, the  desired information is the material “throughput” for each pile. The throughput should be  expressed in tons per a given time period.  Table A5-10. Data Inputs for Loading and Unloading of Materials  particle size (e.g., 10µm if PM$_{10 }$ is desired). Once the PM emission factor is estimated, it can  then be multiplied by the quantity of material transferred to or from the pile during the desired  time period, to obtain the total PM emissions in pounds. This is expressed by  Equation A5-15  ( Particulate Matter Emission from Loading and Unloading of Material Piles ).  Equation A5-15. Particulate Matter Emission from Loading and Unloading of Material Piles  43$_{ }$