Little Giant 10EN-CBA-SFS - 1/2 HP Cast Bronze Submersible Sump Pump w/ Vertical Float Switch (20' cord)

This would really depend on the dilution rate of that water softener. Does your sump basin normally have water in it to help dilute that brine? If not, it's not good for this and most other sump pumps. Your best option in that case would be something like the Little Giant 10EN-CBA-SFS - 1/2 HP Cast Bronze Submersible Effluent Pump w/ Vertical Float Switch. If the brine is diluted, the Wayne pump will suffice, but it still will not last as long as it could, and the warranty would be void. This is all assuming that you have a normal 5-10 foot discharge head lift with a maximum 5 - 50 foot horizontal run.