ABSTRACT
An air quality impact analysis (AQIA) is required for Prevention of Significant Deterioration (PSD) permitting and dispersion modeling is needed in order to conduct a health risk assessment. This chapter presents the use of dispersion models in air quality permitting. Dispersion modeling is an area that requires substantial training, and except for the simplest models available, professional expertise is needed. Therefore, the goal of the chapter is to identify what is needed to conduct dispersion modeling, what information will be sought from the facility or project proponent, and how to assure quality in the modeling that is carried out. It discusses fundamentals of dispersion modeling, the modeling protocol and how it is developed, input data required for modeling, selection of the most appropriate model, quality assurance, and sources of additional information. AQIAs are carried out using Gaussian dispersion models — models that use the basic assumption of Gaussian dispersion.
