Condensate Lines

[MattR11]

I have a large freezer with 3 evaporator coils. 1 coil maintains a temperature of -22 deg. F/ 2 coil -20 deg F/ 3 coil -20 deg F. They have a common drain line that runs from coil 3 until it exits out of the freezer 120' later. When we have an issue with defrost with one coil it freezes the line and we spend about 2 days with a torch to melt ice to clear the line and or drain pan. One idea I had was to exit each coil indivivualaly out of the freezer but the condensate water would dump into a grass area that has very little drainage for it to run into the ditches. Another idea was to run each line out the freezer into the floor drain like it is now but no into a common line. Please send any ideas this is a very expensive problem that needs addressed. All lines are insulated and have heat trace.
Thank you in advance.