USEPA Air Quality Models

Models are available, individually, from tlie National Teclinical Information Service (NTIS) on microcomputer disks. Regulatory and Air Quality models will also be available as a package. Most of the disks must be transported (uploaded) to IBM 3090 niacliines however, some models do have PC executable code. 

Several of the numerous USEPA regulatory models and programs available are 

BLP (Buoyant Line and Point Source Dispersion Model) is a Gaussian plume dispersion model associated witli aluminum reduction plants. 

CALINE3 (California Line Source Model) is a line source dispersion model tliat can be used to predict carbon monoxide concentrations near liighways and arterial streets given traffic emissions, site geometry, and meteorology. 

COM2 (Climatological Dispersion Model) is a climatological dispersion model tliat detennines long temr quasi-stable pollutant concentrations. 

CRSTER estimates ground-level concentnitions resulting from up to 19 colocated elevated stack emissions. 

MPTER is a multiple point-source Gaussian model vvitli optional terrain adjustments. 

PTPLU is a point-source dispersion Gaussian screening model for estimating maximum surface concentrations for one-hour concentrations. 

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Several air quality Hg intensive sites exist and could be used as templates to determine what additional air quality measurements should be included in evaluating the performance of air quality models. These include the USEPA SuperSite programs (http //www.epa.gov/ttn/amtic/supersites.html) and the Southeastern Aerosol Research and Characterization (SEARCH) project (http //www.atmospheric-research.com/ studies/SEARCH/index. html). 

The USEPA recognized that, in calculating the atmospheric dispersion of air pollutants, it was important to maintain consistency among air quality analyses thus, the USEPA published two guidebooks to assist in modeling for air quality analyses Guidelines on Air Qualiti/ Models (Revised) (1986) and... 

Air quality modeling is necessary to ensure that a source is in compliance with the SIP and New Source Review requirements. When air quality modeling is required, the selection of a model is dependent on the source characteristics, pollutants emitted, terrain, and meteorological parameters. The USEPA s Guideline on Air Quality Modeling (40 CFR 1, Appendix W) summarizes the available models, techniques, and guidance in conducting air... 

Air Pollutants Exposure (APEX) model Stochastic time series simulation model producing probabilistic exposure distributions Used by USEPA to evaluate national ambient air quality standards (also part of Trim.Expo model) USEPA (2005b)... 

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