PERRY, Kan. (AP) — Students at a northeast Kansas high school must undergo random drug testing to participate in extracurricular activities.

The the policy took effect last week at Perry-Lecompton High School as the new semester began. School officials say the goal is to provide students with an incentive to turn down illegal drugs or alcohol.

American Civil Liberties Union attorney Doug Bonney says that since the mid-1990s, the U.S. Supreme Court has ruled the drug testing of students involved in extracurricular activities is constitutional. Bonney says the ACLU disagrees with the decision.

Perry-Lecompton High School Principal Mike Copple says drug tests will cost the school $39 per test and alcohol screenings will cost $79 per test. He wouldn’t say how much money was set aside for the testing.