Roommate problems?

I live in residence on my college campus with 3 other guys, I’m having problems with them not cleaning up after them selves( its been at least 3 weeks since they have taken out their garbage and done their dishes) and smoking (cigarettes, weed which is strictly prohibited in the residence ). I take care of myself and take my own garbage out and do my own dishes each week. I understand that we all live together and are supposed to share the load of cleaning but every time I ask them to clean and take out the garbage they brush me off and say they will do it later ( they never get to it ). I’m a nice guy and try to avoid conflicts if possible, but I cant take it anymore. There are people here I can talk to about it but I feel like if I go to them then it will somehow make things worse here.