Present your concerns. Ask what programs are in place to counsel, educate and support students on matters of substance abuse. Check campus bulletin boards and newspapers to see if there are plenty of activities or events offered that are alternative to keg parties. Some colleges have substance-free dorms. Visit one and talk to students to get their ideas on the subject.
Most colleges have computer matching services to pair roommates.
When you begin college, request a roommate who is also seeking a substance-free living mate. Although substance abuse will probably always pervade our campuses, students and parents can and should treat the issue the same way as SAT scores and all the other concerns about applying to college.