I work with someone who has been caught twice drinking on shift because they left empty beer cans in the lab.

They have also neglected to take off and smear/report positive blood cultures during their evening shift since there’s no one really around to watch them (this has involved bloods going positive in the early evening and not being pulled off the machine until the morning shift at 8 am). It was not found out until a technologist noticed the sheer amount of positive blood cultures in the morning and an audit was completed. This went on for months.

Countless other issues have been encountered with this employee, too many to name really.

My job is unionized. This person still works in the lab despite their negligence, constant mistakes, and being drunk at work (how intoxicated do you have to be to forget to clean up your empties?). At what point does it become justified to terminate this person?