Three Canadian environmental assessments (EAs) were chosen as case studies. Each undertaking is an incineration facility. The EAs are analyzed to determine their approach, methods and techniques for predicting impacts on surrounding air quality. A methodology for objectively assessing these EAs is based on a literature search, and extensive criteria are devised. The major finding of the report is the limited nature of the description of the manner in which decisions were made, the methods used for prediction, and a lack of sufficient presented data to allow a decision-maker to understand the conclusions drawn. Simple solutions are presented to improve the ability of the EA document to facilitate decision-making based on the common findings of the three case studies.