We've had several users ask Technical Support about having solute routing included in GMS, specifically by having it included in our stream/river packages for MODFLOW. The online guide to MODFLOW shows that the SFR package has the capability for including solute data in the MODFLOW simulation run, but requires the use of MODFLOW-GWT. The request then is to add a solute routing interface to the existing SFR2 package interface and include MODFLOW-GWT with GMS for just this circumstance. The users requesting this feature have mentioned that this is essential to their work.