Computer air modeling guidance document for aggregate operations that will use actual emission data generated by the aggregates industry. This includes an extensive compilation of all current state and federal modeling policy and guidance. The guidance document also identifies states that lack comprehensive aggregate industry air modeling guidance, provides consistent guidance for those states backed by appropriate technical theory and creates a single guidance document for all aspects of how to model an aggregate facility. The Air Quality Dispersion Modeling document provides methods for appropriately characterizing fugitive sources such that the modeled parameters, and thus calculated concentrations, accurately reflect the sources in question. Discussions on regulatory guidance are included, as well as summaries of the data and technical theory used to develop the suggested methodologies.