AT123D

Groundwater Transport and Fate Model AT123D is a generalized three-dimensional groundwater transport and fate model. AT123D is an acronym for Analytical Transient 1-, 2-, and 3- Dimensional Simulation of Waste Transport in the Aquifer System. It simulates contaminant transport under one-dimensional groundwater flow. Transport and fate processes simulated include advection, dispersion, diffusion, adsorption, and biological decay. Establish Site-Specific Cleanup Objectives AT123D can model the time-dependent contaminant releases from the SESOIL vadose zone model. The SEVIEW version of AT123D was enhanced to simulate up to 999 years of contaminant migration. Results can be used to estimate how far a contaminant plume will migrate and can be compared to groundwater standards to evaluate risk at specific locations and times. AT123D is an analytical model. This means that contaminant concentrations are determined independently for each node and there is no need to establish a dense grid network of nodes.

History

AT123D was developed by G. T. Yeh (1981) at Oak Ridge National Laboratory. Significant modifications to the version included with SEVIEW, were made by John Seymor (1982), Darryl Holman (1984) and Howard Trussell, (1986) of the University of Wisconsin-Madison. An enhanced version of AT123D that can simulate 999 years of contaminant transport was created by Robert Schneiker at ESCI. The ESCI version also includes a correction to the steady-state calculation.