Solvent  Density (pound/gallon)  Acetone  6.604  Alcohol (ethyl)  6.604  Alcohol (methyl)  6.751  Carbon Tetrachloride  13.315  Chloroform  12.432  Ether  6.136  Isopropyl Alcohol  6.555  Methylene Chloride  11.070  Perchloro-ethylene  13.541  Stoddard Solvent  6.497  1,1,1-Trichloroethane  11.174  Trichloro- ethylene  12.219  Turpentine  7.259  Water  8.345  Table A5-9. Specific Gravity of Common Degreasing Solvents  Source: CRC Handbook of Chemistry and Physics.  Many airports store salt and sand piles on- site for use in maintaining roads and runways during  inclement weather. Fugitive dust emissions occur at several points in the storage cycle, such as  material loading onto the pile, disturbances by strong wind currents, and unloading from the pile.  The methodology for estimating emissions from material storage piles is  provided in Chapter  13.2.4,  Aggregate Handling and Storage Piles 34 , and Chapter 13.2.5,  Industrial Wind Erosion 35  ,  of EPA’s AP-42, and are associated with two main activities: (i) batch loading and unloading of  material, and (ii) wind erosion of the piles, respectively.  The major source of PM emissions during “loading and unloading” of piles occurs as material is  dropped from a loader onto the pile or into a truck.  The methodology for calculating the  PM  emission factor for these events is provided in Chapter 13.2.4,  Aggregate Handling and Storage  Piles 36 , of EPA’s AP-42, and is based on mean wind speed, material moisture content, and cutoff  34  EPA, AP-42, Chapter 13.2.4,  Aggregate Handling and Storage Piles ,  http://www.epa.gov/ttnchie1/ap42/ch13/final/c13s0204.pdf.  35  EPA, AP-42, Chapter 13.2.5,  Industrial Wind Erosion  http://www.epa.gov/ttnchie1/ap42/ch13/final/c13s0205.pdf.  36  EPA, AP-42, Chapter 13.2.4,  Aggregate Handling and Storage Piles ,  http://www.epa.gov/ttnchie1/ap42/ch13/final/c13s0204.pdf.  A5.3.6.1  Methodology - Loading and Unloading of Material Piles  A5.3.6  Salt and Sand Piles  APPENDIX A5$_{ }$ 42$_{ }$