Why Does My House Smell Like Sewage? A Richmond, KY Plumber Explains

1. Dry P-trap

Every drain in your home has a P-trap — the curved pipe under the sink that holds water and blocks sewer gas. If you have a guest bathroom sink or floor drain that goes weeks without use, that water evaporates and sewer gas gets in. Fix: run water in every drain for 30 seconds once a week. Costs nothing.

2. Cracked or broken sewer line

If the smell is worse when you flush or run water, a cracked lateral sewer line underground is likely. The gas is escaping through the crack and finding its way into the house. We’ll camera scope the line to confirm before recommending repair. In Lexington’s older neighborhoods (Chevy Chase, Ashland Park) and downtown Richmond, clay sewer lines 50+ years old are the most common culprit.

3. Failed wax ring on a toilet

The wax ring seals your toilet to the floor flange and blocks sewer gas. If the toilet rocks slightly or was ever re-installed without a fresh ring, gas leaks out at the base. Replace the wax ring — it’s a $10 part and a 45-minute job for a plumber.

4. Venting problem

Every drain system needs a vent pipe running to the roof to let sewer gases escape upward. If that vent is clogged (birds nest, leaves, ice), gases have nowhere to go but back down into the house. We see this frequently after hard winters in Madison County and Woodford County.

5. Septic tank backup (rural properties)

If you’re on septic — which is common for properties outside Richmond, Berea, and Irvine — a full tank will cause sewer smell both inside and outside the home. The fix is a pump-out, which we do same day. We also offer camera inspection of the drain field lines if you suspect a bigger problem.

6. Biofilm in drain pipes

Slow drains accumulate years of grease, soap scum, and organic matter. That material rots and produces hydrogen sulfide — the rotten egg sewer smell. A hydro-jet cleaning clears it completely. This is the most common cause we find in Georgetown subdivisions built in the 2000s and 2010s.