The Legionnaires' disease outbreak that occurred from November 2003 to January 2004 in the Lens region raised many questions due to its scale, geographic scope, and duration. Experts from various fields have sought to answer these questions. One of them specifically concerned the location of confirmed cases, which were situated at greater distances from the presumed source of contamination than is typically observed. Modeling the atmospheric transport of pollutants is clearly important for understanding these phenomena. The investigations conducted by the National Institute for Industrial Environment and Risks (Ineris) presented in this article address the atmospheric dispersion of potentially contaminated water droplets originating from an industrial facility and released into the air by cooling and water treatment equipment.