Alcohol is typically not allowed on any school premise and in most, if not all, districts would be a fire able offense.
The episode opens with a scene where Zach is leading a group of students in singing a Christian song. Due to the Separation of Church and State, this is an activity which would be unacceptable in a public school like Abbott, a fact which nobody notices or comments on. Janine even lists the primary reason why this is a problem in the very next scene, that the school includes children of many different faiths by pointing out "Not everyone celebrates Christmas".