- One-Pipe System A plumbing system where a single pipe handles both wastewater discharge and ventilation. - Key Feature A single pipe receives waste from multiple fixtures and also carries away sewer gases through vent pipes connected to the system. - Alternative Systems - Single Stack System Similar to the one-pipe system, but often without extensive venting, relying more on the inherent trap seals. - Two-Pipe System Uses separate pipes for wastewater discharge and for venting. - Single Stack Partially Ventilated System A variation of the single stack system with limited or strategically placed vents.