Work is repetitive and never ending. I would say "The worst part of this job is..." but as there are so many aspects of the job that are bad, it would be challenging to narrow the field to three, let alone one.
The laborers are great. They work hard and are dedicated to the work they do. Unfortunately, it is like "Groundhog Day." The work is the same every day, literally. I come from the school of "fix it right the first time and move on." Unfortunately, too often bandages are applied and the root cause is never addressed, leading to repeat work. Safety is a buzz word, but injuries are common due to carelessness and inadequate safety mechanisms.
Constant rework, working 6 or 7 days per week is the expectation, a lot of infighting/back stabbing exhibited by management, plant manager is aggressive, closed to others opinions, and verbally abusive.