MT3D Version DoD_1.5
An Upgrade to the USEPA Version for
U.S. Army Engineer Waterways Experiment Station


This version of MT3D was developed at the University of Alabama for US Army Engineer Waterways Experiment Station from the public domain version (Version 1.1, 1/1992), currently distributed by US Environmental Protection Agency (USEPA). Listed below are the major modifications and enhancements made to this version:

  1. Replacement of the simple arithmetic averaging scheme used for computing the cell concentration from particle concentrations in the MOC solution by a volume-based weighting scheme. This change can significantly reduce the mass balance discrepancy in the MOC solution with irregular grid spacing.
  2. Modification of the operator-splitting scheme in the MOC solution for improved solution accuracy in modeling very heterogeneous aquifers.
  3. An updated Dispersion package to use "dispersion conductance" in computing dispersive fluxes for better handling of dispersion cross terms.
  4. Improved handling of the transient groundwater storage term and non-uniform porosity distribution, eliminating mass balance errors caused by these conditions.
  5. Improved time-stepping control for the explicit, upstream finite-difference solution to guarantee stability.
  6. Support for the MODFLOW BCF2 package with the rewetting capability.
  7. Support for the MODFLOW Stream-flow Routing (STR1) package. Note that the RIV1 and STR1 packages must not be used in the same simulation.
  8. Allow multiple stress period transport simulation in conjunction with a steady-state flow model with only one stress period. The flow-transport link file saved by MODFLOW containing flow velocity and sink/source information needed for transport simulation is read only once by MT3D.

This version will be replaced by the new MT3DMS code when it becomes available from the US Army Corps of Engineers.

Download Instructions

  1. Download the files "" and "" (Modflow with Version 2 of MT3D interface);
  2. Uncompress the downloaded files using PKUNZIP in two separate temporary subdirectories;
  3. Copy the executable MT3D executable file MT3D.EXE and Modflow file MODF.EXE to the desired subdirectory whose path is included in the DOS PATH statement;
  4. Check the README files for more information.


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Last modified: June 14, 2001