Some ground rules for alcohol I put in place after my 1st semester in college back in the day.
1) No drinking during the weekdays during the semester or season. It is not easy to wake up to go to class or focus if you are tired and hungover.
2) Don't sleep through/skip classes. Being on your own for the first time, it is very easy to fall in the trap of sleeping through or skipping classes, especially if you are out drinking the night before. Do a quick calculation for how much each class is costing you. Each time to skip you are flushing that money down the toilet.
3) Don't drink before meets or hard workouts. During the season, that typically means only going out once a week on a Saturday night. Off-season, Friday and Saturday nights.
4) Don't get totally wreaked on that one night out a week (i.e. worshipping the porcelain princess). Remember, you still need to do a long run on Sunday and it is never fun running extremely hungover burping up whatever the heck you drank the night before.
5) Morning runs - Commit to do them. And by committing that means you need to get to bed at a decent time during the weekdays.
6) If you are under age - If you can tell there is a crazy party going on from a block or two away or from walking through the halls in your dorm, don't go in and find a different party. The cops or campus police will be there shortly and then you will have a nice underage drinking ticket/citation to explain to your parents and coach.
7) Remember, you do not need to go out once a week and drink to have fun either. Fun is hanging out with your friends not just getting hammered.
Oh and as people pointed out. Going out once a week to drink with friends is not a functioning alcoholic, it's a college kid binge drinking.