Polluted Water

Polluted Water is a liquid element that appears throughout the colony as a waste product, a natural geyser output, and a useful midgame resource. It is commonly generated by bathroom use, various generators and machines, and several natural sources, and it can also be found in the world from Polluted Water Vents and Cool Slush Geysers. Although it is often treated as waste, Polluted Water is valuable because it can be cleaned into Water, used directly by several plants, and converted into other resources.

Polluted Water continuously emits Polluted Oxygen from its surface, even in a vacuum, until the pressure above it reaches 1.8 kg. Emission only occurs to the tile directly above the liquid, and only the top 1000 kg of each tile contributes to the emission calculation. A full tile can release about 30 kg of Polluted Oxygen per cycle on average, but the actual output is inconsistent because it is chance-based. Spreading Polluted Water across multiple tiles increases total offgassing, while stacking it reduces efficiency. Bottled Polluted Water behaves differently: as a bottle, it releases Polluted Oxygen at a fixed rate rather than by chance, and Polluted Water stored in a Liquid Reservoir does not offgas at all.

Polluted Water is one of the easiest early-game coolants to work with because it has a high specific heat capacity and a wider boiling and freezing range than Water, Brine, and Salt Water. It can be pumped into a Water Sieve and cleaned with Sand or Regolith, producing Water and Polluted Dirt. Germs present in the liquid are not removed by filtration, so contaminated Polluted Water must be handled separately if clean output is required. It can also be boiled into Steam, producing a small amount of Dirt in the process; however, very small amounts will not produce less than 1 g of Dirt, so tiny quantities can effectively turn into Steam only.

Polluted Water is also a crop input. It is required for domestic growth of Pincha Pepper, Thimble Reed, Bog Bucket, and Arbor Tree, and it is consumed by the Fertilizer Synthesizer to produce Fertilizer. In addition, Gulp Fish can convert Polluted Water into clean Water.

Common production sources include Duplicants vomiting from stress or missing the toilet, Lavatories, Showers, Wash Basins, and Sinks. Among these, Lavatories are especially notable because they are water positive, producing more Polluted Water than the clean Water they consume. Other sources include Carbon Skimmers, Algae Distillers, Algae Terrariums, Natural Gas Generators, and Petroleum Generators.

A few practical points make Polluted Water especially useful:

• Duplicants will automatically empty Polluted Water bottles into a Bottle Emptier set to accept them.
• Because Liquid Reservoirs prevent offgassing, they are useful for safe storage or for sealing polluted pools from the air above.
• If you want Polluted Oxygen production, spread Polluted Water over many exposed tiles instead of stacking it into a deep pool.
• Naturally occurring and produced Polluted Water usually contains no germs, so it is worth keeping separate from infected water.
• Even if Polluted Water contains Food Poisoning germs, submerging a Duplicant in it does not apply those germs to the Duplicant.