ISCST3 modeling system consists of the ISCST3 model and the PCRAMMET meteorological preprocessor. ISCST3 is the Industrial Source Complex model, Version 3, which is listed as an "Alternative Model" by the U.S. EPA. ISCST3 is no longer a "Preferred/Recommended Model." AERMOD has replaced ISCST3 as a "Preferred/Recommended Model."
Link to EPA SCRAM website containing codes and documentation for the ISCST3 model.