Signs of a Sewer Line Problem
By the Duncan Family Plumbing team · September 30, 2026
The clearest warning signs of a sewer line problem are multiple drains backing up or draining slowly at the same time, gurgling sounds from toilets or drains, a sewage smell indoors or in the yard, and an unusually lush or soggy patch of lawn above the line. Catching these early can mean the difference between a repair and a full replacement.
Multiple Slow or Backed-Up Drains
A single slow drain usually means a local clog. But when several drains across the house are slow or backing up at the same time — especially the lowest fixtures, like a basement floor drain — that points to a problem in the main sewer line itself, not an individual fixture.
Gurgling Sounds
Air trapped in a partially blocked line often escapes as a gurgling sound from a toilet or drain when another fixture is used. It’s an early warning sign worth paying attention to before a full backup happens.
Sewage Odor
A persistent sewage smell, whether indoors near a floor drain or outdoors near where the line runs, usually means gas or waste is escaping somewhere it shouldn’t — often from a crack or a fully blocked section.
A Suspiciously Green or Soggy Yard Patch
A section of grass that’s noticeably greener, lusher, or wetter than the rest of your lawn — especially if it follows the path of your sewer line — often means the line is leaking and effectively fertilizing the ground above it.
Why Early Diagnosis Matters
A camera inspection at the first sign of trouble often catches a problem that’s still repairable with lining or a spot repair. Waiting until a full backup happens sometimes means the difference has already been made for you — toward full replacement.