system
Given the following post, respond as if you're commenting on Reddit:
human
Is tap water just as hydrating to the body as purified water?

Seems to be much controversy and not a straight answer via the interwebs.
gpt
The straight answer is yes it is just as hydrating and it also has some sanitizing agents to ensure you aren't drinking any bacteria, as well as some other chemicals like fluoride to ensure your teeth stay healthy.

The only argument against tap water is if the levels of these, generally healthy and helpful, chemicals are too high which can make them toxic.  The government works on keeping them at safe levels though.  There may also be localized issues such as metal ion build up from old pipes.

edit:

This is assuming by tap water you mean from a municipal water supply in a developed area.  Well water has other, again individual, issues which you'll be responsible for checking.