Frederik:
First, for the benefit of other users, I want to expressly spell out the crucial legal point on which your Q is based:
ADDICTION to drugs or alcohol IS a disability requiring accommodations to the point of undue hardship under human rights laws.
CASUAL or RECREATIONAL use is NOT a disability requiring accommodations.
RESULT: You’re free to negotiate whatever penalties you want for positive tests determined to be the result of recreational use–minimum 3 days, etc., without accounting for accommodations.
Of course, the standard rules for discipline will still apply–penalties must be fair, proportional, transparent, consistent and meted out after appropriate investigation. But accommodations don’t enter into the equation if the use is recreational.
As for your second Q, I work for a small, non-union organization so our model probably isn’t all that relevant to your situation. But what I can tell you is that your approach of investigating positive tests to determine whether the employee is an addict or casual user is not only widely followed in union settings but mandatory for all settings.
The scale of penalties will depend on a bunch of factors including the type of workplace you have, whether affected employees are safety-sensitive and, of course, your bargaining leverage vis-à-vis the union.
Hope that helps.
Glenn Demby, 203 354-4532
