Standard: API 4020


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TRC has prepared this report to evaluate dispersion formulas and air quality models. It is intended as a guide to the petroleum industry engineers who a r e required to make computations and decisions in regard to atmospheric emissions. It provides general and specific guidance on the use of the formulas, together with comments on when the formulas give realistic answers. This report is to be used in conjunction with working handbooks, such as the 1968 ASME Guide, or Publication 999-AP-26 of the Public Health Service (Turner's Workbook [13]).

The report is organized into major sections. Part I provides comments and analysis on some of the formulas involved in computations of:

• short-term average concentrations, point and line sources;

• long-term averages surrounding a point source;

• stack emissions;

• mathematical models for area and multiple sources.

Results are presented of empirical tests or practical trials which serve to illustrate the reliability of the recommended methods.

Part II consists of a more thorough development of the physical, meteorological and mathematical theory and background of the various formulas. The engineer, even one who ordinarily looks with suspicion on theoretical mathematics, should find Part II rather straightforward and useful. He will gain an appreciation for the theoretical basis of the various formulas and can, with practice, be able to work on a more assured basis with the dispersion formulas. For ease of reading and reference, source material appears in both parts.

One note of caution must be stated: Neither Part I nor Part II is intended to provide a "cookbook" approach to solution of atmospheric dispersion problems. Meteorologists experienced in atmospheric diffusion and turbulence will be required for some case studies. If a contaminant emission could be critical in its effects on a surrounding community, the approach represented by the formulas may not be definitive enough, and expert help may be the more direct and practical approach.

Organization: American Petroleum Institute
Document Number: api 4020
Publish Date: 1969-10-01
Page Count: 100
Available Languages: EN
DOD Adopted: NO
ANSI Approved: NO
Most Recent Revision: YES
Current Version: NO
Status: Inactive