Aqua Pura

Aqua Pura is literally "Pure Water" that is available once the DLC: Broken Steel is installed. It replaces any and all "pure" water from Fallout 3, and may contain the F.E.V (Forced Evolution Virus) depending on the player's decisions pre-Broken Steel.

Drinking the water after choosing to infect it with the F.E.V will result in a player debuff (-2 STR and -1 INT) and, if consumption is repeated, death.

You will find many barrels of Aqua Pura everywhere when you download Broken Steel