Sewage is a brown liquid, transportable via pipes. Sewage is created when the population consumes water and food. It is a danger to the population and must be removed from the habitation deck for long-term survival.

Sewage is made available on the main floor for processing via a sewage pipe. The sewage can then be bottled with a loader, or processed back into useful resources by piping it into a waste treatment machine (to start).