The answer to 'how does sewer line work' is that a sewer line is the underground pipe that carries wastewater from your home's plumbing fixtures, such as sinks, showers, and toilets, to the municipal sewer system or a septic tank. The sewer line typically runs from the home's main plumbing stack, which collects waste from all the drains, and slopes downward to the connection point with the city's sewer main or the septic tank. Gravity is the main force that moves the wastewater through the sewer line, though some systems may use a sewage ejector pump to help push the waste along.
Proper maintenance and care of the sewer line is important to prevent clogs, leaks, and other issues that can lead to backups and costly repairs. This includes regularly inspecting the line for any signs of damage or blockages, and having a professional plumber perform a sewer line inspection and cleaning as needed.