Where to get rid of dirty oil?

I did an oil change last week and was very lazy afterwards, i left the oil in a bucket outside.
Of course it rained that night, pretty badly, and now i have dirty watered down oil. Will a general service station take it? Or do i have to do something special?

Almost all the school bus garages and trucking firms will take used oil. Most of them burn it in special heaters designed to burn used motor oil and transmission fluid. Dan