Sewage plumbing systems include all of the following EXCEPT:

In sewage plumbing systems, the primary components involve the infrastructure necessary to transport waste away from homes and buildings. This system includes pipes that conduct waste, drainage systems that receive and route this waste efficiently, and ventilation systems that ensure proper air circulation and prevent the buildup of harmful gases.

Faucets, while essential in plumbing for the distribution of water to various fixtures, do not fall within the category of sewage plumbing systems. Instead, they are more associated with the supply side of plumbing, delivering fresh water rather than handling wastewater. Therefore, the answer identifies the component that does not belong in the context of sewage plumbing, as it specifically refers to the systems designed for waste removal and management.