Sorry to hear of your struggles with this and I also congratulate you on the decision to make your life and the lives of your children a priority.
As many have mentioned, there's probably not all that much you can do at this point. If he is already aware that you are leaving and the reason is his drinking, he's still in heavy denial. The act of you leaving is about as major of a "consequence" that an addict can face in and of istelf.