The plumbing in your home is composed of two different main systems. One is designed to safely and effectively distribute drinkable water. We often refer to this as the domestic water supply. The other is the sewer system, a combination of all of the various waste and air vent pipes in the home. All of the various pipes have different names, definitions, functions, and codes. When properly designed, installed, and free of defects, the entire system works in harmony. As a whole, these pipes of the sewer system carry all of the waste and wastewater from your toilets, tubs, showers, and sinks away from the house and into the city sewer or septic system.