[ben_w]

Given I have no idea what the water is used for, I would defer to an expert.

If it goes through copper pipes, picks up heat, then leaves… my expectation is that this is fine, and I could drink it without further processing. Perhaps even insulate the pipes then it's a free source of pre-heated water and we can save energy.

If the exit pipes cross-connect with the staff sewage lines, then it needs full processing like any other waste water stream.

Without having someone actually look at the setup, I'm not going to know which it is, and there's likely a lot of other possible configurations besides those two.