Septic Tank Sewage Odor Inside & Outside Why The Sewage Smell In House?

Septic Tank Dude Author at Septic Tank Dude
Jack has been working all of his life in the septic tank maintenance, cleaning and pumping business. In 2020 when COVID hit he decided to retire from pumping septic tanks and use his knowledge to help out readers of Septic Tank Dude. Jack has a wealth of knowledge to share on septic tanks, leach fields and much more.
Jack Cacy

The sewage smell in house is not something you want to live with and can be embarrassing when having family or guests around. Septic tank smells outside can also stop you from inviting friends and family around for barbeques or just make your outside area and pool area unwelcome. Having a smelly septic tank can also lead to homeowners resorting to bleach and other products that will only make your septic tank smell get worse. In this article, we will give you all the tips and tricks you need to get rid of your septic tank foul smell. Make sure you read to the end to discover if the sewer smell or rotten egg smell in your house can be deadly or if they are harmful.

There is no mistaking that your septic system is a stinky business. What many homeowners don’t realize that inside your septic system is an ecosystem that is fragile. A small imbalance in the bacteria in your septic tank can lead to sewer smell or septic tank gases escaping. To ensure that the bacteria and ecosystem in your septic tanks are operating at the ideal level, try a septic tank bacteria tablet down the toilet each month. Many of our readers have commented that for less than $9 per month it has saved them a lot of stress and money.

Quick links for your smelly septic problems

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6 Tips for how to get rid of septic tank smell in house

  1. Check your septic tank – When was the last time your checked your septic system or had your septic tank checked by a professional? If you’re looking for the poop smell, this should be the first place you start. Problems IN your septic tank will lead to a septic tank smell in house and in the backyard and no one wants a sewage backup. The fixes for this are to have your septic tank pumped, and to the septic tank pros about your septic odor and a clean out of your septic tank. A good article to read on the warning signs of a full septic tank will give you some clues.
  2. Switch from the chemicals – Often if your septic tank problems are not in your septic tank it can be in the plumbing on the way to your septic tank. Using chemical cleaners in the bathroom shower, toilet or other drain pipes that are not suitable for a septic system (bleach is the biggest) will lead to a reduction in the septic system beneficial bacteria and in some cases, you can wipe them out. The bacteria in your septic system are there to break down the waste. If this has happened to you, look at the best septic tank treatment article.
  3. Watch what you flush – There are a small number of things that go down your toilet, be careful that wet wipes, sanitary products, paper towels or nappies are not going down your toilet. Another area to look at is your kitchen garbage disposal. With some of the vegetables or fruit you will be disposing of, elastic bands or plastic labels can also go down the disposal.
  4. Check your riser covers – A riser cover, which is often installed over your septic tank, allows direct access into the septic tank. These are intended to be firmly closed (usually with a rubber seal and screws) so the septic system is a closed system so no bad smell or leaking odors get out. If you detect a foul odor in the vicinity of your riser, it’s most likely due to the cover rather than anything else. Any holes or fractures in the concrete lid or plastic lid depending on the age of your septic tank would allow odors from your tank to escape into the air above ground. If your concrete lid is cracked or not in good repair, it is important that you get this fixed.
  5. Get more beneficial bacteria – The right level of GOOD bacteria in your septic system is crucial to getting rid of those septic tank odors and sewer gas smell. Just like we prevent diseases and colds by taking care of our health, the same principle applies to your septic system. Test out this inexpensive septic tank tablet as a maintenance treatment each month to ensure your tank is effectively breaking own solids and scum so your tank will thrive and septic odors or nasty odor will be reduced.
  6. Check the vent stack– The vent stack is also called a plumbing vent and is located on the roof of your house. It works to allow the septic gas such as carbon dioxide, hydrogen sulfide and so on to escape and pressure in your sewer line to equalize as wastewater flows from your washing machine, toilet, sinks etc. A common problem with this vent stack is it freezes in cold weather or becomes clogged by birds or leaves or other debris and pressure in your pipes can’t equalize. To fix this you can use a high-pressure jet or water blaster to clear the vent. You can also buy vent filters or covers. Charcoal filters are particularly popular as charcoal is extremely good at neutralizing foul smells and septic odors from sewer air.


Sewage Smell In House – 3 Options For Sewage Odor Neutralizer

If you have tried the five tips above or got a professional plumber in to look through your pipes and got the ok. Sometimes you can’t help the fact that septic odor or sewer smell will get into your house. Here are some natural septic tank solutions that will help you neutralize the sewer odor until it passes.

  • Get scrubbing with baking soda – This is a natural odor remover that has been used in washing and cleaning solutions for many years. Scrub surfaces with baking soda and a little water for a natural odor neutralizer and temporary removal of septic odors.
  • Clear sludge from drain covers – If you have checked your septic tank and there is no septic odors or sewer gas odor coming from there, it may be time to look a little closer to home. In your sewer lines between the house and the septic system sludge can build up on drain covers. If there is a build up you can use a septic tank sludge dissolver treatment to remove this. If paper towels or wipes have been flushed these can often partially block the sewer lines, releasing a sewer smell. Luckily this is a simple fix, you can simply wash with hot water and a septic-safe cleanser, then put back.
  • The one-two punch – If you have tried the first two sewer smell neutralizing tips and it is not a clogged drain, it may be time for the ancient one-two punch of baking soda and vinegar. A question we get asked a lot by readers is “is vinegar safe for septic systems”. White vinegar does have an antibacterial effect and can unbalance the bacteria in your tank, so it is important that you limit the use baking soda and vinegar or eliminate the use altogether. If you are concerned that your sewer lines may have sludge or a small blockage causing a sewer smell in your house, it may be safer to call a plumber to put a snake down your pipes. If you would like to try the baking soda and vinegar (sparingly) then boil the jug or kettle first as you will need boiling water. Add at a ratio of 1/2 baking soda in the toilet or down the drain line first followed by 1/2 vinegar and flush the toilet or let it go down the drain followed by boiling water.

septic tank bacteria maintenance tablets


Why does my house smell like sewer – septic odors in different rooms

Each wetroom in your house has a different use and therefore a different potential reason you are getting septic tank odors or septic smell in that room. We will cover the main rooms you will get house smells in and how you can potentially remove the foul odor.

4 reasons for septic tank smells in bathroom

If there is anywhere in your house that you could say “smells like poop in my house” it would be in the bathroom. These are the top 3 reasons we have found for septic tank smells in bathroom:

  1. Unused bathroom – If your wife has ever said the unused bathroom smells like sewer, that could be because of a dry P trap or dry S trap. The water traps under a sink or near floor drains are there to use water to create a seal or barrier to keep the sewer system or sewer gases from entering the bathroom. So if you smell sewage in your spare bathroom and it has not been used for a while, the quick answer is to run water down the sink, bath and shower to re-establish the water barrier due to a dry P trap or S trap.
  2. Loose or faulty toilet wax seal – If you have a sulfur smell in bathroom or it smells like rotten eggs in your bathroom then the leading cause of this is a loose toilet gas ring, also called a toilet wax ring. This forms an airtight seal between the underside of your toilet bowl and the flange in the ground. A wax ring may endure for 20 years or more if properly cared for, but excessive plunging can damage it. Other telltale indicators that the wax ring is failing include if your toilet wobbles or water seeps from its base. To eliminate the septic odors or septic house smells (essentially methane gas escaping), you might need to replace the wax ring.
  3. Plumbing vent/ vent stack – The plumbing vent is located on the roof and allows sewer gas pressure in the pipes to escape. This can sometimes be a source of a bad smell.
  4. Broken sewer line or leaks – Tree roots or obstructions can cause sewer leaks from time to time. Often tree roots can penetrate pipes and work their way up to the toilet or drains, expanding as they go and loosen or crack pipes. If you have septic tank odor in bathroom or septic tank smell from toilet then there are some common signs to look out for in the main sewer line:
  • Gurgling noises in your toilet or drain pipes when running the washing machine or having a shower
  • Sewer odor from the plumbing system
  • Water or sewage backup or flooding


3 fixes to house smells like sewer when doing laundry

We spend a lot of time in the laundry room doing laundry and often we can smell sewer gas or septic odors in the laundry room. Here are the main reasons that house smells like poop when washing clothes:

  1. Clothes dryer – If your clothes dryer is not vented outside, then there is a good chance you have a moisture build up issue causing an odor problem. If you smell a sewage or septic tank odor when drying clothes then you should look at getting it vented outside.
  2. Clothes washer – On the other hand, if you have rotted out rubber door gaskets, worn-out impellers in your washing machine and lid gasket not sealing properly, then every time you do a load of washes you could be getting septic tank smells in laundry room.
  3. Water trap problems – Just like in the toilet, there is a water trap under the floor drain or in the laundry room that is there to prevent sewer system gases from entering your house. If this has become dry because you have been away or you have not used your drains, this will emit sewer gas and you will be able to smell sewage in the laundry. This is a quick fix, to stop sewer gas escaping you just need to run water down the floor or shower drain for a short time.


Is the sewer gas or sulfur smell in bathroom or house dangerous?


Sewer gas from septic systems is a complex mix of gases and compounds. In tiny doses, sewer gases are not poisonous. However, some of the gases contained in its composition can significantly enhance high-level toxicity. Sewer gas smell or septic tank odors are primarily made up of hydrogen sulfide, ammonia, methane and carbon dioxide, further information on these:

  1. Hydrogen sulfide – Hydrogen sulfide has been linked to causing damage to the body’s oxygen systems. In high doses, hydrogen sulfide can result in a variety of unpleasant symptoms as well as organ damage and even mortality.
  2. Ammonia – This might already be familiar to you as a common chemical cleaning compound. It is especially noted for its distinctive odor. Ammonia has the potential to irritate the eyes, nose, and throat. At higher concentrations, it can induce organ damage or death.
  3. Methane gases and carbon dioxide – These are relatively harmless to humans in low doses. Methane however can become combustible in large amounts. However, ammonia is also highly flammable raising the question that sewage gases at concentrated levels could be a fire hazard.



What Are the Symptoms of Exposure to Sewer Gas?

The initial sign that sewer gas has entered your home is a bad smell — think sulfur smell in bathroom, sewage smell from shower or rotten eggs smell. Symptoms associated with mild sewer gas include:

  • Headaches
  • Nausea
  • Vomiting
  • Fatigue
  • Dizziness
  • Poor concentration
  • Poor memory

If sewer gas enters your house in high quantities, you can anticipate more serious symptoms, such as:

  • Loss of smell
  • Eye, mouth and throat lung irritation due to ammonia
  • Eye irritation
  • Pink eye
  • Seizures
  • Possible coma and death


Why does my septic smell outside

bad smell outside house

Last time you invited friends over for a barbeque and just before they arrived there was a terrible septic tank smell. With septic tanks being located outside along with the drain fields and venting, there are a large number of factors that could result in a sewer smell outside or septic tank odors outside.


Top 3 reasons for septic smell outside

  1. Septic tank is full – The most common reason that you are getting septic tank odors outside or around your septic tank is because you have a lot of solids or scum in your tank and the system is overloaded. Often you will get sewage backup into the house or drains as a bad sign. Two options, the least expensive option is to purchase septic tank bacteria tablets to break up the solids and remove scum. If this does not work within 3-5 days you will need to get your septic tank pumped and then carry on with the septic tank tablets to ensure this does not happen again.
  2. Leach field problems – Also called drainfields, this is the last stage of the septic system process. The drain fields return the treated wastewater to the soil via a number of drip pipes under the ground or under a mound of sand, gravel and earth. Common problems are tree roots getting into the pipes, the drain field has reached the end of it’s life, the small pipes are blocked or crushed. A major sign of a spetic problem with your leachfield is your septic tank is getting full and operating above the normal operating level. See this article – just had septic tank pumped and full again!
  3. Inspect septic tank risers & manholes – Depending on the age of the septic tanks you could have a concrete or plastic septic system. Check that the manhole cover is properly sealed (could be concrete, metal or plastic lid).
  • Plastic manhole – check the rubber seal is sealed properly so no toxic gases or foul smell can escape.
  • Concrete manhole – make sure there are no cracks or chips out of the edges of the concrete, this must be sealed properly otherwise you will have a foul smell and sewage gases escaping.


If you have a concrete or plastic manhole that is not sealing correctly then you will need to get this repaired to stop as the best way to for how to eliminate sewer odor outside and stop the foul odors from continually escaping.



Frequently Asked Questions about aerobic septic system smell in house

Is a septic tank odor normal?

There will always be septic tank odors when you have a septic tank. Constant septic tank odors are not normal and need to be addressed by following the suggestions in this article, or calling a professional plumbing service. Also see this article on how often you should pump a septic tank.

What are plumbing vents?

Plumbing vents is also called a vent stack or plumbing vent that is located on your roof. The main reason for the vent pipe is to do just as it sounds to vent the pipes when wastewater is moving through your pipes and the sewage gases are pushed ahead of them.

If you ever have gurgling in your pipes when you use your washing machine or dishwasher or the shower drain, this is a sign that the system is not venting correctly and you have a vent or plumbing problem.

Could the nasty odor inside my house be from putting the wrong things down my drains?

Yes this is a major cause of a plumbing problem when cigarette butts, coffee grounds or other organic matter that does not break down easily is put down the toilet or sink. Wipes, feminine hygiene products and nappies are also bad for the septic tank. Things that people don’t think about are excessive hair can block the small pipes in your sewage system. This often leads to homeowners putting things like chlorine bleach down the kitchen sink, toilet or shower drain. Chlorine bleach is one of the worst things you can put into your septic systems and will not cure slow drains.




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