How old is he ? It'll make a lot of difference as to how you should react.

Is his aim bad or is he deliberately weeing on the floor?

He is 4 years old. I think that he is delibrately doing it (not positive because I'm not there when it happens). The school just talked to him and he was put on yellow (which means he go in trouble and doesn't get a sticker for the day), also he lost 6 minutes of play time.

Also, how have the school dealt with it ?