Why does my basement smell like septic?
Mia Kelly
Published Jan 13, 2026
A strong sewer smell coming from your basement is most often caused from a dried out floor drain, a bad ejector pit seal, improperly vented appliances or fixtures, or even a damaged sewer line. Floor Drains – Rarely-used floor drains in your basement are typically the source of the sewer stench.
How do you get rid of sewer smell in basement?
Simply pour a few gallons of water to re-establish the proper water barrier. You can add a small amount of vinegar to help remove any persistent odors. If you don't use basement toilets often, the water from the P-trap can evaporate just like with floor drains. Give the toilet a flush or two to remedy the problem.
How do you get rid of septic smell?
Start by pouring ¼ cup of baking soda down the drain, and then leave it for about 10 minutes. Then, follow it with one cup of vinegar. Let the mixture fizzle and work for a few minutes, and then finish by turning on the water and running the disposal to clear out any leftover food waste.
Why does my house suddenly smell like sewage?
If you are detecting foul sewer odors inside the house, this means that there is a weak link somewhere in your plumbing system. Possible sources include bathroom sink drains, toilets, kitchen drains, basement drains, old cast iron piping, or even the vent stack that goes out through your roof.
How do I get rid of sewer smell in my house?
These are the steps you must take:
- Pour a cup of vinegar into the unused drain.
- Follow it up with one-fourth cup of baking soda.
- Leave the drain for a couple of hours to let the vinegar and baking soda set.
- After two hours or so, pour a gallon hot water down the drain. ...
- Pour a half-cup of chlorine bleach down the drain.
Why does my basement smell like rotten eggs?
Sewer gas. That “rotten egg” smell in the basement is sewer gas, or hydrogen sulfide. It comes from decaying organic matter like sewage in your plumbing lines, according to The Scottish Plumber on Angie's List.
Why does it smell like poop in my basement?
If it smells like garbage, rotten eggs or feces, you may have a bigger problem on your hands. This odor is generally the result of a build-up of waste materials found in a septic system or public sewer system. It may be caused by a crack or clog in the plumbing system itself, or a crack or clog n the venting pipes.
Why does my house smell like septic?
A septic odor in your home usually means there's a plumbing problem, but not all issues require calling a plumber. The floor drain trap in your basement could be dried out, allowing septic tank gases to vent back into your house. Periodically filling the drain traps with water will correct the problem.
Why does my basement smell like sewage when it rains?
When it comes to a sewage smell in your home after rain, the most common culprits are cracked pipes and clogged drains. If you have trees in your yard, roots are a common cause of cracked or broken pipes. In addition, tree roots can also crack your septic tank.
Is it normal for septic to smell?
A well-maintained septic tank should never smell, so detecting a foul odor coming from inside or outside your home isn't a good sign. The smell could either be a sign of something serious or something minor.
Why does my septic smell like rotten eggs?
Sewer gas. Every type of septic system or sanitary sewer system produces sewer gas. Properly working systems vent the sewer gas away from households and businesses. But, when things are not in pristine working conditions, the gas begins to leak into your home, causing the dreaded rotten egg smell.
What does septic odor smell like?
Septic Stench: What That “Rotten Egg Smell” Means and What to do About It. A sewer gas odor can come from your household septic system or the sanitary sewer system. If you notice a foul smell that is causing a problem in your home, it may be sewer gas.
Can I pour bleach down my basement drain?
Bleach and cleaning fluids create toxic gasses when mixed together. If you pour bleach and other cleaning agents down your sink drains, and they mix in your pipes, you can contaminate the air in your home with the resulting gas created. The following items should never be poured down the sink with bleach: Vinegar.
Why does my sump pump smell like sewage?
Sewage Infiltration
As the sump basin collects excess groundwater, sewage that has infiltrated the basin creates noticeable sump pump smells in your home. The bad smell of sewage from the sump pit is sometimes infrequent early on but becomes more consistent as the problem persists.
Why does my house smell like poop?
A regular sewer-gas smell is just a bad stink with a definite odor of feces and sometimes a rotten-egg (hydrogen sulfide) smell and/or a moldy mustiness too.
How do I get the rotten egg smell out of my basement?
If the dry trap is to blame, the fix is simple: Just turn on the faucet a few seconds and let the water drain out. The water will fill the trap and effectively block sewer gases. If the smell is strongest in your basement, the floor drain trap may have dried out.
Why does my basement smell weird?
Bad basement smells come from humidity and moisture that comes up from the ground. Since the basement is below ground level, this moisture never really goes away and just keeps accumulating. This causes mold and fungus to grow and spread.
Can you put vinegar down the drain?
With time, baking soda and vinegar may work as a natural drain cleaner on weaker drain clogs, and the benefits of regular drain cleaning can help keep your drains free of clogs. But for tough drain clogs that need to be dissolved right away, you may want to use a stronger drain cleaner, like Liquid-Plumr.
Where does the drain in my basement go?
Your basement floor drain is located at the lowest point of your basement, and its job is to direct any water safely away from the house and to the sewer system or municipal storm drain system. This keeps your basement floor dry and prevents flooding, which may damage personal belongings.
Can you pour Lysol down the drain?
Liquid, gel and powder water-soluble household cleaning products can be flushed down the drain. Solid products include soap pads, sticks, towelettes.
What does sewage backup smell like?
Sewer gas is a byproduct of the breakdown of natural human waste. It comprises a mixture of gases, including hydrogen sulfide, ammonia, and more. The hydrogen sulfide in sewer gas is what gives it its signature rotten egg smell.
What are the signs of a sewer backup?
Early signs of sewer backup
- Gurgling sounds coming from a drain.
- Unusual odors coming from the sinks, showers, or drains.
- One or more drains moving slower than usual.
- Water backup into the shower or tub.
How do you tell if the sewer is backing up?
Warning Signs of a Sewage Backup
- Sewage-Like Odors Coming From The Drain.
- Bubbling Drains Or Toilets.
- Slow Draining in Multiple Fixtures.
- Clogs In Multiple Drains At Once.
- Sewage Coming Out Of a Cleanout Pipe.
What does a broken sewer line smell like?
The sewer line is the underground pipe that carries all your wastewater from the home to the sewer system. Four of the most common signs of a broken sewer line include multiple slow drains, foul smells inside the house, mold or mildew in the basement, and an increased presence of pests.
Can you pour bleach down a smelly drain?
Pour Some Bleach in There: Bleach kills the majority of odor-causing bacteria. If you kill the odor-causing bacteria, you'll destroy their smell as well. To use bleach to kill odor-causing bacteria, first, fill your sink with hot water. Then, add about one cup of regular household bleach to the sink.