A plumbing system performs the simple job of supplying water to the house and removing its waste water.

Because a plumbing system ties into a sewer/septic source, it must prevent the possible danger of sewer gases seeping back into the waste pipes. So, we'll talk about how vents and drain traps handle that problem.

Drain-Waste-Vent (DWV) System

The drain-waste-vent system transports all the used water and waste from the house to the septic/sewer system. It's a network of drain pipes that runs to all the sinks, toilets, baths, showers, and washer.

Most newer waste systems use rigid plastic PVC (polyvinyl chloride) or ABS (acrylonitrile butadiene styrene) pipe that are sealed with glue. Older homes generally have had cast iron pipe sealed with lead solder.