Aqua Pura

 is literally "Pure Water" that is available once the DLC pack Broken Steel is installed.

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

Bugs

 * Giving any amount of Aqua Pura to Water Beggars will result in their death at the next map change, regardless of whether or not the Aqua Pura contains Modified FEV.
 * Sometimes the message 'Aqua Pura has worn off' will appear, even if you drink non-FEV water. This is most likely because the game applies the same action to infected and uninfected Aqua Pura.