MMSOILS is based on the premise that contaminants are transported through the environment by multiple media (air, water, soil). The model considers the physical and chemical properties of the contaminants, as well as the environmental conditions that affect transport. MMSOILS can be used to predict the concentration of contaminants in each medium at various locations, downwind or downstream from a source. The model can be used to estimate exposure to contaminants from multiple sources, including transportation activities. MMSOILS is a tool that can be used by environmental regulators and planners to assess the potential risks of contamination from transportation activities. The model can also be used by various industries to evaluate the potential impacts of their operations on the environment.