every case is different. throughout my probation i failed most UAs all for marijuana but nothing ever happened. after i paid all the fines they basically let me go because the probation system is so backed up in minneapolis. but i have friends on probation for misdemeanors who have had probation violation hearings from failing just one UA. i was on felony probation and all i ever heard was "you're still testing positive" my P.O. would ask me if i still smoked and i never lied to her i always said yes.