The potential for air-quality impacts from heavy mechanized vehicles operating in the training ranges and on the unpaved main supply routes at Fort Bliss was investigated. This report details efforts by the staff of Pacific Northwest National Laboratory for the Fort Bliss Directorate of Environment in this investigation. Dust emission and dispersion from typical activities, including move outs and combat training, occurring on the installation were simulated using the atmospheric modeling system DUSTRAN. Major assumptions associated with designing specific modeling scenarios are summarized, and results from the simulations are presented. Major findings include the following: • Move-outs produce substantially higher PM 10 concentration contributions than combat training under the same meteorological conditions. • Impacts from move-outs tend to be highly localized, and the impact location is dependent on the prevailing wind direction in relation to the direction of vehicle travel along the move-out route. • Low-wind-speed days generally result in higher 24-hour average PM 10 concentration contributions when compared to high-wind-speed days, especially for combat training scenarios. Finally, this report examines concentration contributions from dust generated by wind erosion within the Fort Bliss installation. Factors contributing to wind-generated dust are summarized, and Fort Blissspecific vegetation cover and surface soil texture datasets are described. Results from two DUSTRAN wind erosion simulations-a high-and low-wind speed case-are contrasted and used to quantify the range of wind-generated dust concentrations that might be expected from the Fort Bliss site. v Acronyms BFIST Bradley Fire Support Vehicle