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Dirty water is a consumable item in Fallout 4. It may also be consumed directly from open water sources and other contaminated water sources in the environment.


A carton of plain river water, contaminated by radioactive fallout.

At a cooking station, dirty water can be used to make various stews and soups, when combined with other ingredients. Three cartons of dirty water can also be turned into one purified water. At a chemistry station, dirty water is used in the construction of the berserk syringe and lock Joint syringe ammunition for the syringer.



Survival mode

In Survival mode, dirty water can reduce the Sole Survivor's thirst, though at the cost of increasing radiation and increasing the risk of contracting disease. Cartons of dirty water can be created by using the "Fill Bottle" option if one is next to a water source (river, sea, lake, pond, puddle of stagnant water, or contaminated water fountain) and if the player character has one or more empty bottles in their inventory. The player character can also drink directly from the water source. The healing from such sources is reduced to one tenth of non-Survival healing, i.e. 1.5 HP, and only applies if the character is not suffering from any current thirst status effects.


  • Due to the ability to build water-producing settlement objects, dirty water is less readily available to the player than purified water. Dirty water can only be created in Survival mode, and only by filling empty bottles at a water source, expending the bottles in the process. Empty bottles are not recovered after the dirty water is consumed.
  • Comparing cartons of dirty water to dirty water drunk directly from an open water source:
    • Drinking directly from most open water sources inflicts 3 rads on the player character and restores 15 HP (1.5 HP in Survival mode). There are some exceptions:
      • Drinking from Glowing Sea water, Lake Quannapowitt, and some other rare sources inflict 10 rads. (These sources also have double the normal environmental radiation, i.e. 20 rads/s)
      • Drinking from Swan's Pond inflicts 15 rads.
      • Drinking from the Mass Fusion reactor water inflicts 100,000 rads and 15 HP damage, which is instantly fatal. (Exposure to this water inflicts 50 rads/s).
    • Drinking the dirty water item (carton) inflicts 7 rads and restores 20 HP
    • So a proportional amount of normal open water needed to heal as much as the dirty water item itself (20 HP) would inflict 4 rads, apart from in Survival mode.
    • In Survival mode, in contrast, healing 20HP would require 13 and 1/3 gulps of open water, dealing 40 rads.