This question of mine was closed as to broad. Reasons given where that a good answer would be beyond the scope of SE. Since then there's also a request for reopening, not by me (reopen-voter, speak up!). Is it salvageable? How?
I'm not 100% convinced by the close reason. My previous employer had a sheet of paper with 5 bullet points as 'best practices' for similar plants, obviously not a great example. Seminars on plant safety (not WWTP, similar) I attended dealt to 80% with legal issues and Quality assurance. So I'm not 100% convinced that that there are no meaningful yet short answer possible.
To be sure, I'm not in any role where I'm responsible for anyone's safety beyond mine. There may be a difference in the legal obligations consultant engineers have between Germany and elsewhere, maybe this misunderstanding is part of the problem?
P.S. Not that his has bearing on the discussion here, but two things I will do is hunt down safety manuals of the plants I visit and pursue my employer about this issue.
P.P.S While my employer offers seminars on safet around the office once a year, on-site practices are not covered. They are in trouble when something happens to one of us, but that's nothing I want to see happen.