The Necropolis sewers are locations in Necropolis.
The sewers are divided into three sections, each accessible from its own ground district by manholes. The tunnels serve as the only connection between the different districts of Necropolis.
The underground ghouls who reside in the Hall of the Dead section of the sewers will tell you the location of the water chip. When you inform them that you will take their only supply of water they request you to fix the water pump by finding the parts in the Watershed sewers section to the north.
The Necropolis sewers appear only in Fallout.