When you say it's in conduit? Do you mean PVC?
I'f it was ran in EMT(conduit) underground,in Florida,thats a problem.
If it's in Pvc,with the correct connectors,and couplings,i'm not sure how water is getting in ,unless,its where the PVC is 90 going up.
If it is EMT in the ground,(which it is not rated to do,you can run it outside exposed,with the proper fittings,but not bury)you might as well use direct burial cable now.
Good luck.