Why Your Sink Smells Like Sewage (Even After You Clean It)
Stephanie Carwell - 04/21/2026
You clean your sink.
You rinse it.
Maybe you even use a cleaner…
…but the smell is still there.
If your sink smells like sewage — especially in homes across Columbia and Lexington — the problem usually isn’t what you think. And in most cases, surface cleaning won’t fix it.
The Smell Isn’t Coming From the Sink
What many homeowners don’t realize is:
👉 The smell is usually coming from inside the drain line, not the sink itself.
Over time, buildup forms along the walls of your pipes:
- Grease
- Food debris
- Soap scum
- Bacteria
This creates a layer that can start to rot — producing a strong sewer-like odor.
Why It Keeps Coming Back
You may notice the smell returns quickly after cleaning. That’s because:
- Cleaners only treat the surface
- They don’t remove buildup deep in the pipe
- Bacteria continues growing below the drain
This is especially common in kitchen sinks.
Other Possible Causes
1. Dry or Weak P-Trap
If a drain isn’t used often, the water barrier can evaporate. This allows sewer gas to rise into your home.
2. Venting Issues
Blocked vent pipes can cause sewer gases to push back through drains.
3. Developing Drain Blockage
If you’re also noticing:
- Slow draining water
- Gurgling sounds
- Odors getting stronger
There may be a restriction forming in your drain system.
When It’s More Than Just a Smell
If the odor is combined with:
- Multiple drains smelling
- Sewer smells in other areas
- Water backing up
This could indicate a larger plumbing issue. In some cases, leaks can also contribute to odors.
What Actually Fixes It
The real solution depends on the cause:
- Buildup → professional drain cleaning
- Dry trap → running water
- Vent issue → inspection
- Blockage → clearing the line
Temporary fixes usually don’t last.
When to Call a Plumber
If the smell keeps returning or gets worse, it’s time to have your system inspected.
Freedom Plumbing Inc. serves:
- Columbia
- Lexington
- Irmo
- Chapin
- West Columbia
- Cayce
Call (803) 447-0471
Final Thoughts
If your sink smells like sewage even after cleaning, the issue is likely deeper in your plumbing system.
Addressing it early prevents bigger problems — and eliminates the smell for good.