Drain & Sewer
Sewer Line
A sewer line (also called a sanitary sewer line or sewer main) is the underground pipe that carries wastewater from a building to either a municipal treatment system or a private septic system. On properties connected to municipal sewer, the sewer line runs from the home to the city main beneath the street. On properties with private septic systems, the sewer line (often called the building drain or house-to-tank line) connects the home's plumbing to the septic tank.
In Minnesota, residential sewer lines are typically 4–6 inches in diameter and made of cast iron (older homes), clay tile (very old homes), Orangeburg pipe (a mid-century fiber material that degrades badly), ABS plastic, or modern PVC. Each material has different failure modes and service life expectations. Cast iron and clay tile pipes are common in homes built before 1970 and are frequently the subject of root intrusion and joint separation issues.
What This Means for You
If your home was built before 1980 and you've never had the sewer line inspected or cleaned, a camera inspection is a worthwhile investment — especially before buying a home. Old clay tile lines with root intrusion can collapse suddenly. A clean, inspected line gives you peace of mind; a compromised line should be addressed before it becomes an emergency.
Related Terms
Lateral Line · Cleanout · Tree Root Intrusion · Pipe Belly (Sag) · Hydro Jetting · Camera Inspection