AirWare:     urban air quality
assessment and management

The Industrial Source Complex Model (ISC) is a multiple point sources and area source model developed by the US Environmental Protection Agency, EPA. It is one of the UNAMAP guideline models. ISC is also one of the central models in the AirWare air quality management information system.

ISC is a Gaussian plume model that can describe individual episodes of a few hours or long-term, eg., annual, average conditions. A basic assumption of the Gaussian model is steady-state conditions, ie., both the emissions and the weather conditions in terms of wind speed, directions, air temperature, stability class, mixing height, and precipitation, are assumed constant.

ISC (Industrial Source Complex Model) has been specifically developed to simulate air pollution due to an industrial plant, taking accurately into account the effect of high stacks on the behaviour of the pollutant plume. It may be applied in urban or rural environment with a moderately complex terrain. Its numerous options allow to compute the dry deposition of the pollutant downwind the stacks, to model the plume hight accounting for the hydrodynamical effects, to simulate the impact of linear, area and volumetric sources. It works with non reactive pollutant, including particulate matter, but may include a first order decay.

The program has two versions. In the long term version (ISC-LT), it computes average concentration values on an area of few hundred square kilometers for a period like a season or a year, on the basis of the correspondent meteorological data. The short term version (ISC-ST) computes mean concentration values for a period of one or few hours.

AUTHORS

   Curtis P. Wagner
   TRC Environmental Consultants, Inc.
   800 Connecticut Boulevard
   East Hartford, Connecticut 06108

REFERENCES

• G.A.Briggs, "Diffusion estimation for small emissions" USAEC report ATDL-106. U.S. Atomic Energy Commission, Oak Ridge, TN, 1974
• G.A.Briggs,"Plume rise predictions", Lectures on Air Pollution and Environmental Impact Analyses, American Meteorological Society, Boston, MA, pp. 59-111, 1975
• F.A.Gifford,"TURBULENT DIFFUSION TYPING SCHEMES A REVIEW", Nuclear Safety, 17: 68-86, 1976. EPA-450/2-78-027R, GUIDELINE ON AIR QUALITY MODELS U.S. Environmental Protection Agency, 1986;
• A.H.Huber, W.H.Snyder, "Wind investigation of the effect of a rectangular-shaped building on dispersion of effluents from short adjacent stacks", A.E. Vol.16, 1982;
• F.Pasquill, "Atmospheric dispersion parameters in Gaussian plume modeling part II: possible requirements for change in the turner workbook values", EPA publication no. EPA 600/4-76-030b. U.S.Environmental Protection Agency, research triangle, park, nc., 1976;
• D.B.Turner,"WORKBOOK OF ATMOSPHERIC DISPERSION ESTIMATES", PHS Publication No. 999-26. U.S. Environmental Protection Agency, Research Triangle, Park, NC, 1969;

VALIDATION STUDIES

• J.F.Bowers, A.Anderson, "An Evaluation Study for the Industrial Source Complex (ISC) Dispersion Model", EPA Publication No. EPA-450/4-81-002, 1981;
• J.F.Bowers, A.Anderson, W.R.Hargraves, "Tests of the Industrial Source Complex (ISC) Dispersion Model at the Armco Middle-town, Ohio Steel Mill", EPA Publication No. EPA-450/4-82-006, 1982;
• J.S.Scire, L.L.Schulman, "Evaluation of the BLP and ISC Models with SF& Tracer Data and SO2 Measurements at Aluminum Reduction Plants", Air Pollution Control Association Specialty Conference on Dispersion Modeling for Complex Sources, ST. Louis, 1981;