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. Contaminant transport can be simulated:
Version 7.1 of AT123D can simulate over 1,000 years of contaminant transport and contains a correction to the steady state algorithm.
AT123D can model the time-dependent contaminant releases from the SESOIL vadose zone model. AT123D was enhanced to simulate up to 1,000 years of contaminant migration when linked to SESOIL. 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.
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 which can simulate over 1,000 years of contaminant transport was created by R. A. Schneiker at ESCI. This version 7.1 of also includes a correction to the steady-state calculation.