You will save yourself a lot of grief if you repaint your bus anything else but school bus yellow. Many states won't allow a bus to be NSBGY unless it is in school service and soon the entire country will soon be that way it seems--don't want any lester low crotches picking up kiddies I guess.
Many states have laws against dumping grey water (and black water) anywhere--big clean up fines etc. For example, here in KALIFORNIA the only things you can dump fron a vehicle are fresh water and feathers (from LIVE chickens)
Just be safe and enjoy the states!
You might want to repost this under the everything else heading as it will get more views. Good luck