Sewer line basics: your lateral, the city main, and who fixes what

Two different pipes, two different owners

Understanding sewer line basics helps you know who to call and what to expect when there is a sewer problem. Your home connects to the city sewer system through two distinct sections of pipe, and responsibility for each is different.

Your lateral line

The lateral line runs from your house out to the connection point at the city main, usually somewhere under your front yard or the parkway strip near the street. This section is your responsibility to maintain and repair, even though part of it may run under public property near the curb. Harborline repairs, clears, and can camera-inspect lateral lines.

The city main

The city main runs down the street and is owned and maintained by the city, not by any individual homeowner. If a backup is caused by a problem in the main itself, rather than your lateral, that is the city's responsibility to fix, not ours or yours. Part of our diagnostic process, including a camera inspection when needed, is figuring out which side of that connection point the problem is actually on.

Common lateral line problems

• Root intrusion from trees near the line, which is common in older Westside neighborhoods with mature landscaping.
• A bellied or sagging section of pipe that collects debris and backs up repeatedly.
• Aging clay or cast iron pipe, common in homes built decades ago, that has cracked or deteriorated.
• A simple blockage from grease, wipes, or other material that should not go down a drain.

How we diagnose it

For a suspected lateral line issue, we typically run a camera through the line to see exactly what is happening and where. This lets us show you, often on video, what the problem is and whether it is a clearing job, a spot repair, or a longer-term pipe issue. We give you a written price for whatever the camera shows before doing further work.

If it turns out to be the city's main

If our camera inspection shows the issue is in the city main rather than your lateral, we will tell you plainly and let you know it is a matter to report to the city, not something we would bill you to fix, since it is outside our property line and outside our license to repair the city's own infrastructure.

Need a hand? Harborline dispatch is 24/7 at (310) 555-0148.