The IST: Mobile Storage and Transfer Package pane is used to activate the Immobile Storage and Trnasfer package. It is on the MODFLOW Packages and Programs dialog box under Groundwater Transport| | GWT: Groundwater Transport.
Each transport model can have multiple Immobile Storage and Transfer packages but they all use the same options. The Immobile Storage and Transfer package can store budget information in either a binary file, a comma-separated value (CSV) file or both.
Sorption with a LINEAR, FREUNDLICH, or LANGMUIR sorption isotherm can be simulated. If sorption is simulated in the IST package it must also be simulated in the MST package using the the same option.
Decay can be simulated as either zero-order or first-order decay.
If Save sorbate concentration (SORBATE) is checked, sorbate concentration will be saved in a binary file whenever aqueous concentrations are saved, as determined by settings in the Output Control option. The file will have the extension ".SORBATE".
