I have a roommate who is filthy and stopped going to work. He's not on the lease I am. I decided to move out can evict him sense I'm leaving?

Can who evict him? You? No, you are not the LL.

If you move out under the terms of your lease he will be left there. The landlord will deal with him. 

YOU have a month to month tenant. You have to give him notice according to your state. If he stays in the apartment and the landlord has to get rid of him YOU will be paying rent, fees and court costs.

Yes you need to give him the correct notice in writing for him to leave, as you are the contracted tenant you are legally liable for the rent...so moving out can only be legally done once your termed contract ends or with the agreement of your landlord

Yes. You have to serve him a proper written notice to vacate in accordance with your local laws.