Yes lance it's water - ice melt water.
The cooling plate in a fridge ices up over time so an automatic defrost timer applies gentle heat to melt the ice to keep the fridge frost free.
The melt water runs into drain channels at the back and through a drain hole. It evaporates down below.
Your drain hole is blocked - it happens - clean it out with a curtain wire - it's a domestic form of personal hygiene.
Good Luck..., September 2015
