it's not 'immediately dangerous', but it has had higher than federally allowed levels of one of the (carcinogin) bleach byproducts for a year now--after a year, you have to disclose that sort of thing. (also, outside the bldg where I work, it's kinda opaque a lot of the time).
I feel much better about my bad habit of just having a diet coke for lunch every day.
And I've made sure to fill my water bottles at home.