ISCST3 Tech Guide

Gaussian Plume Air Dispersion Model

1. Preface


This User's Guide provides documentation for the Industrial Source Complex (ISC3) models, referred to hereafter as the Short Term (ISCST3) and Long Term (ISCLT3) models. This volume describes the dispersion algorithms utilized in the ISCST3 and ISCLT3 models, including the new area source and dry deposition algorithms, both of which are a part of Supplement C to the Guideline on Air Quality Models (Revised).

This volume also includes a technical description for the following algorithms that are not included in Supplement C: pit retention (ISCST3 and ISCLT3), wet deposition (ISCST3 only), and COMPLEX1 (ISCST3 only). The pit retention and wet deposition algorithms have not undergone extensive evaluation at this time, and their use is optional. COMPLEX1 is incorporated to provide a means for conducting screening estimates in complex terrain. EPA guidance on complex terrain screening procedures is provided in Section 5.2.1 of the Guideline on Air Quality Models (Revised).

Volume I of the ISC3 User's Guide provides user instructions for the ISC3 models.