MT3DMS and MT3D-USGS can be used to simulate solute transport. Either can be used in the example. In this case, we will use one of them to simulate transport of solute from the disposal pond.
To activate MT3DMS or MT3D-USGS, select Model|MODFLOW Packages and Programs... and then expand MT3DMS or MT3D-USGS. Check the check box for the MT3DMS Basic Transport package (BTN). The GCG Generalized Conjugate Gradient Solver will also be activated; it is required with MT3DMS and MT3D-USGS. On the MT3D options tab, you can choose to use either MT3DMS OR MT3D-USGS. You should also activate the Advection, Dispersion, and Sink and Source Mixing packages for MT3DMS.
You must define at least one mobile species. In this case, we will use chloride. Define it on the Chem Species pane.
On the MT3D Options tab, select MT3DMS.
Click OK to close the dialog box. You will get a message telling you that you will need to run MODFLOW again before you can run MT3DMS.
