main sewer 
						Large-diameter pipe that collects wastewater and sewer runoff and conveys them to a treatment plant.
						
				  	 
					
						gas main 
						Pipe that conveys gas to buildings and houses.
				  	
 
					
						water main 
						Pipe that conveys drinking water to buildings and residences.
						
				  	 
					
						service main 
						Extremely high-flow pipe linked to smaller distribution pipes with far smaller volumes of flow.