An air quality CE significance rating procedure was developed through adaptation of existing EIA significance evaluation methods combined with expert opinion and professional judgment. The procedure includes 18 factors for evaluation relative to specific pollutants and spatial boundaries. A significance score results from the assignment of importance weights and intensity levels to the 18 factors. Techniques for evaluating and implementing new opportunities in mitigation are then described.

From the EIS and EA reviews, the lessons learned were used to develop an 8-step Cumulative Air Quality Effects Assessment (CAQEA) method which addresses topics such as past, present, and reasonably foreseeable future actions; emission data estimates for pertinent actions; modeling of quantitative and qualitative changes to background air quality; and significance determinations for air quality CEs.

Information gathering and analyses related to RFFAs may be the most difficult aspects of addressing CEs. Accordingly, an 8-step Conservative Determination Method is proposed herein for delineating RFFAs for inclusion in CEA.

This research develops methods and procedures for the assessment of cumulative effect (CEs) of air quality. The analysis components of this research are: (1) a review of recent environmental impact statements (EISs) and environmental assessments (EAs); (2) a review and analysis of the legal interpretation of what actions are defined as reasonably foreseeable future actions (RFFAs); (3) a review of existing air quality effect quantification models and selection of those that are best suited to cumulative effects assessment (CEA); (4) the development of a conceptual approach for significance determination for CEs and associated opportunities for mitigation; and (5) the application of the developed procedures at a U.S. Air Force base.

Air quality modeling provides a scientific means for relating source emissions and atmospheric processes. A qualitative decision approach applied to a suitability review of numerous classes of models resulted in the identification of three classes that fully meet the criteria requirements for, and desirable attributes of, cumulative air quality effects quantification. These classes are: Simple Area Source, Rollback, and Box models.

Finally, a demonstration is provided of the CAQEA method applied from the perspective of an Air Force base's influence on a small southwestern city. This case study identifies the assumptions needed to overcome difficulties in data collection and analysis and the rationale for the decisions made. (Abstract shortened by UMI.)