Necropolis

Sidetracked - whilst intending to sort out the raiders Pipboy reminded me of time running out for the vault water supply so im off to Necropolis
Ghouls, Super Mutants and religious Nuts.
If you take the first pothole and go in the sewers and talk to some friendly ghouls who will inform you of how to get the water chip. Once again you can be evil to the inhabitants by killing everyone, good by helping or indifferent and still achieve your goal.

Super Mutant Dialog can be very amusing and depending on your skills will gave various options really multiple ways to play.
Once you get the water chip return to the vault and then you have more time to travel.