A REVIEW OF PROCEDURES FOR UPDATING AIR-QUALITY MODELING TECHNIQUES FOR REGULATORY PROGRAMS

Air quality models are a key component in determining pollution contro l requirements. To ensure that the best techniques are used, modeling guidance must be flexible and include better techniques as they become available. Revisions to modeling guidance require an assessment of th e scientific basis, a model performance evaluation using observed data , sensitivity analysis for impact on design concentrations and data in put requirements, and public review and comment before formal adoption in regulatory programs. The procedures used in reviewing new techniqu es are examined in this paper, and past actions are discussed. The app ropriateness of adopting a new method for modeling area sources charac terized by low-level releases with little buoyancy is provided as an e xample of the revision review process. While this process is lengthy, it ensures that decisions on potentially costly pollution controls are based on full public participation and sound scientific developments.