Sewer Gas Smell & Septic Tank Odor FAQs

Gas Odors & Leaks - Immediate Safety Hazards FAQs

Gas seeping into my home is making me dizzy.

Gas is seeping into my home ; the kitchen and bathroom are the worst rooms and I get very dizzy help On 2017-03-22 by carla

by (mod) - Watch out: immediate safety hazard warning

Carla

Watch out: Open windows, get some fresh air ventilation, go outside, call emergency services.

Sewer gases can be explosive as well as risking asphyxiation (death) in severe cases.

Sewer / Septic Gas Odors vs Exhaust Fan Use FAQs

Foul odor from the shower fixtures when I run exhaust fan

When I run the shower and exhaust fan in the bathroom at the same time a foul odor is coming from the door behind the shower fixtures. If I don’t run the fan then no odor. It seems like the exhaust fan is creating air pressure pulling the odor in behind the shower fixtures.

This just started to happen after many years without a problem. The smell dissipates quickly after shower and turning off exhaust fan. Thank you. On 2019-11-24 by Steve

by (mod) - foul odor is coming from the door behind the shower fixtures: vacuum by fan draws plumbing vent leak gases or other leak damage

Steve

Taking a wild guess about "the door behind the shower fixtures" I think you may be describing an access panel providing a way to inspect and repair the tub / shower controls.

Take a look in there and you may see that the tub overflow or drain trap are not properly installed, such that when a powerful exhaust fan runs and the bathroom door is shut the fan may be drawing sewer gases into the room.

The other most-common cause of this problem is loss of water in the fixture traps because of inadequate vent piping.

by Steve

Thank you. I did mean the access panel door. Does it make sense that if the fan is not running and I use the shower no smell.

The smell only occurs when the fan is running along with the show.

The access door is not a perfect fit and when the fan is running I can actually feel a small amount of air being pulled from behind the access door along with the smell. Thank you for reviewing this situation.

by (mod) - running a bath fan can cause back-venting of sewer gases

Steve

Quite possibly running a bath fan can cause back-venting of sewer gases out of an open drain; more-likely if the plumbing vent system is improper or inadequate.

by Steve - foul smell in the bathroom - diagnosis continues

Thanks again. I just used the other bathroom. They are side by side. Showered and ran the vent fan.

There was a noticeable foul smell in the bathroom when finished. In this bathroom I cannot tell where the odor is coming from.

Not from the access panel which is side by side with the other bathroom. No issues in this bathroom either when exhaust fan not running. I have lived in this house for 30 years and this never happened before.

What could cause it to start occurring now. Should I contact my regular plumber to check? Thanks again.

by (mod) -

Perhaps a blocked plumbing vent, a leak developed in a plumbing vent or drain, or a partly clogged drain, or a failing septic system.

It's worth investigating further - before there is a drain backup and before there is a worse or even dangerous accumulation of sewer gas indoors.

by Steve - why there is a smell only when the exhaust fans are running in the bathrooms

Thanks again. Any thoughts as to why there is a smell only when the exhaust fans are running in the bathrooms.

Does that signify anything special. I just ran the exhaust fan in the bathroom without running any water and the smell is coming through the access panel although not as strong as when water running. Are the pipes that go to the roof vent located in the attic?

by (mod) - bath vent fan can create negative air pressure

I suggested earlier that especially in a smaller bathroom with its door and any windows closed, when you run an exhaust fan that creates a negative pressure in the bathroom that an draw odors from a smelly wall cavity or defective plumbing vent.

Thanks to your website I have solved so of my numerous plumbing problems. Now need help with sewer gas odor troubles.

Thanks to your website I have solved so of my numerous plumbing problems. I have plumbing drain, ventilation, and sewage gas odor.

My concern now is the toxic odor which permeates every floor of my home.

The ventilation system terminates outside the second floor bathroom on a 90 degree angle by a window

I plan on cutting the 90 degree fitting off and placing a box with a fan installed on the bottom of the box the now vertical vent pipe will enter the box the inline fan will pull the gases thru the box into a newly installed ventilation pipe which will run vertically through the attic floor continuing through the attic terminating through the roof as per code.

The box will be air tight allowing proper sewage gas termination. Will my idea work properly. On 2019-07-29 by jwrow123

by (mod) - DIY plumbing venting warnings

JW

I want to help but am not smart enough to analyze your design from e-text. But I can give some general warnings:

In general an exhaust fan can help force draft where you want it to go, but I'm left with some considerable worries including:

1. the system may suck traps dry and can cause back-venting of dangerous sewer gas into the home

2. the system doesn't work unless there's electrical power

3. the design may be missing a simpler solution if we understood why there is a venting problem in the first place; I'd want a very thorough inspection of the house DWV by an expert plumber or code compliance officer.

Details of causes and cures of smells traced to problems with the plumbing vent system are

at PLUMBING VENT DEFECTS & NOISES 

and

at PLUMBING VENT BLOCKAGE ODORS 

Lingering rotten egg smell after using the shower

we bought our home last year. We noticed a lingering sporadic rotten egg smell in bathroom, stronger after showering.

We had the wax ring of toilet replaced and are sure the drains in basement are kept full with water to keep gas smell from leaking into the house.

Nothing has worked , after cleaning drain with different things. We have had plumber after plumber come out for 2 months now and no one can find or fix it. HELP! On 2017-08-16 by dianne

by (Mod) -

Dianne,

It may be your water supply itself, or a water heater contaminant; try reviewing the list of rotten egg or sulphur or sewer gas odor sources

at SEPTIC / SEWER ODOR SOURCE TABLE

Sewer gas odor present in my mobile home even after faulty toilet seal was fixed

Sewer gas odor present in my mobile home due to a faulty toilet seal. Plumber resolved seal today but odor is still present in the home. Any idea of how to get rid of the stinky odor? On 2017-04-04 by Linda

by (mod) - get rid of lingering sewage odor after a toilet repair

Linda:

Start by using a household cleaner to clean all around the toilet: floor, lower walls, nearby fixtures all that may have been wet during toilet repairs.
Then ventilate the space.

if the odor remains there may be another problem to find.

See LEAKY TOILET SEAL REPAIR

Sewage odor in bathroom when we do laundry

We have an old home with a new septic system. When we do wash, there is a sewer odor in the adjoyning bathroom.

We have snakes the line, ran water, fun got loads of laundry of wster, vinager, baking soda. Checked the vent on the roof. We still have the smell. Lost on how to detect where the smell is actually coming from. Can't get rid of it. Drain in laundry room has water in it. Help? On 2017-02-24 by Cynthia k.

by (mod)

Check for a dry plumbing trap in the smelly bath; check for a loose toilet or one not sealed to the waste pipe flange in the floor (that may require removing and replacing the toilet); consider hiring an inspector whose combustible gas detector can pinpoint the odor entry point. Keep in mind that the sewer gas leak may be from a leaky or un-glued vent pipe joint in a wall, floor or ceiling;

Smell of sewer gas and propane in just one bathroom

I have an odor in the house that I just can not figure out - combination of sewer gas and propane. Concentrated in one bathroom - no where else.

Go into the basement - underneath that bathroom - no smell - just one room. Checked all the drains and traps, they are used on a regular basis.

Had the plumber out - could not find anything, had the septic guy out, he says the system is working fine.

Replaced the wax ring on the toilet - still get the odor - sometime strong, sometimes weak - weather, temp does not matter - very hard to describe - any suggestions?

Are there any meters that might help detect this? Should I call the EPA air quality division? LOST! On 2016-11-17 by Kevin

by (mod): Watch out: check first for a propane gas leak - and fire or explosion hazard

Kevin

Watch out: first to avoid a fire or explosion, be sure that there is not a natural gas or LP (propane gas) leak: if you have one of those fuels, turn it off, or go outside and call for emergency services 911.

When odor is in just one bath I'd look closely at

- a bad toilet wax seal

- a partly clogged drain

- defective venting

- listen for siphoning or gurgling when the toilet is flushed

See TIF 8800 GAS DETECTOR 

When we run our salon's big ceilng vent fa a horrible sewage/rotten egg smell comes out from somewhere

We put a large ventilation fan on the ceiling of our small salon (800 square feet).

Every time we run it with all doors closed, horrible sewage/ rotten egg smell came out quickly. Tried to find the source of that smell, eventually it seems to come from the space above the ceiling! Why? And how to eliminate that? Thank you On 2016-04-11 by Olivia

by (mod)

Olivia,

I can offer only general suggstions as I cannot know why, from a brief e-text, the odor you describe is being found.

I can GUESS that there may be an open plumbing vent in the ceiling space that is venting into that area due to the negative pressure created by the fan. Sewer gases can smell like rotten eggs.

So can other chemicals and contaminants.

Your installer or service company or building owner's handyman needs to actually look with care throughout the ceiling area to spot possible plumbing or other odor sources.

A plumbing vent that empties into the attic or ceiling space needs to be piped to outdoors above the roof - IF that is the problem

Horrible sewer gas smell after we used a drain cleaner in the shower drain

I put a drain cleaner in my shower drain. It worked great but now we have a terrible sewer gas smell. We have a septic system. What can I do or use to get rid of this odor. Has never happened before

We have a mystery odor in our houses that causes sore throats. It might be sewer gas, the only thing is it gets absorbed by fabric. It stays on our clothes when we leave the house. We threw away our couch and mattress because they absorbed the smell. Does sewer gas behave this way? Thanks. On 2015-10-24 by Anonymous

by (mod)

Where is the sewer gas originating? If it is at the shower drain try flushing the drain throughly with cold water;

Another uglier possibility is that a caustic drain cleaner precipitated the failure of an already thin, corroded drain line (metal of course); the result could be a leak and thus odors. Look for leaks or leak stains below the shower.

Keep us posted.

Odor at toilets when we run other plumbing fixtures

We purchased a home that was 9 years old with its own septic system. We had the septic checked and replaced the toilets but any time that we do a load of laundry and to a lesser extent take showers or run the dishwasher we get an order in the rooms where the toilets are.

The interesting thing is it is almost like it is coming through the ac/heating vents. Out next step, we believe, is to have someone come out to conduct a smoke test. Is this a good next step? On 2015-02-24 by Mark

by (mod) -

Mark

When you replaced the toilets were the wax rings leaky?

Do sinks gurgle and drain poorly? If so there may be a venting problem.

I'd look closely at where your air returns are located to see if they're picking up odors from an identifiable source or if they're causing (dangerous) backdrafting.

A smoke test of the vent system might help but is not an exhaustive test. Leaks in a vent system in walls, for example, are likely to be missed.

Need a Sewer Odor or Gas Detector

My house is 30+ years old. about 5 years ago sewer gas odor was detected in the daylight basement where there is a floor drain. The drains are all abs plastic, except that when I opened up the concrete floor and exposed the trap, it was cast iron. (Presumably because the plastic traps in those days did not have a built in tap for the primer water.)

I found out that while an old cast iron trap will hold water molecules, it can deteriate over time and allow gas molecules to pass through the pipe walls

I replaced the trap and the odor disappeared for a couple of years. Unfortunately the problem has returned.

By the way, it is only present during cold weather. I recently opened a wall in the smelly area and replaced a couple of vent pipe couplings that were leaking gas, but still have the problem.

Just wondering if I am going to have to open all the walls and floors and redo all the drains associated with this area of the house.

Half would be under concrete and finished floors, ugh. Also, I found the leaks initially by injecting a detectable gas into the system.

Can anyone share a potent gas and very sensitive detector that could be used in the search? (Dec 4, 2014) David

Reply:

Sure - see our description and use suggestions for the TIF8800 at GAS DETECTION INSTRUMENTS

That inexpensive gas detector will respond to septic or sewer gases and is quite sensitive.

I Don't like the TIF8800 gas detector

The gas detector show in the article is poor at best. The sensors give false positives all the time. This sensors register humidity many times versus a true gas detection. On 2019-05-14 by John

Answer by (mod) -

If you are using a gas detection instrument that happens to be sensitive to the chemistry of the particular odor you can sometimes use the gas detector to track an odor to its source. That's particularly true if you using a leak detection device and if the leak happens to be in piping. For other odor sources that are more general or widespread it may be difficult

But yes you need to adjust the detector's sensitivity level (that's what the control knob is for), and you need to know that it will respond to moisture.

It remains a good cost-performer if used with thought.

Sewer Gas Odor Fixes & Repairs FAQs

Mysterious Sewer odor solved by fixing a rubber gasket at the house trap

Mysterious Sewer odor solved!!!
For the past 2 years we have had a sewer odor in my basement within 5 minutes after a long shower or my kids using the tub.

I have had a half dozen plumbers in, we tore apart the basement ceiling and walls in search of the smell.. no luck! We did smoke tests... No Luck!! we flooded the waste pipes with water... No luck...

THEN after a 3 day 8 hrs a day plumber marathon (over $2k) and the rest of my walls torn down, and we dug up my pipes outside my house and my cesspool.

We found it. The rubber gasket after the house trap that connects the cast iron 5 foot pipe to the outside of my house and the metal house trap was venting a small amount of gas ONLY when water was flowing through it...(hence no smoke during that test) We proved it with a lighter (NOT RECOMMENDED) but when water flows in large volumes, such as a tub draining... the flame flickers and continues to do so for a seconds after the large water flow.. note it does not happen if a toilet flushes.

Temporary fix was to put some Mortite around the pipe and gasket... 5 days no smell.. Now we have 2 choices, cut out the main trap and put in new pipes, or... just tar the gasket....( a 10 dollar fix) - Paul, Long Island, NY 2/1/12

Reply:

Thanks Paul, this experience report will help other readers. - Ed.

 

Bedroom built over a cesspool in a crawlspace; is it safe to work on a plumbing problem there?

My elderly brother-in-law built his wife bedroom over a cesspool.

There's a 3 foot crawlspace and a vent pipe on the exit line just outside the foundation. With this cold winter the question (my wife) came up if the pipes froze if I would crawl under the house to fix or unthaw the water lines

I told her I wouldn't do it and I would not reccommend anyone else to do it.

What can I buy to test the air quality in the crawlspace and the bedroom. Better yet I need to scare my 77 year old brother-in- law into putting in a proper septic system Thanks Ed Garner dogacreswv@gmail.com On 2015-02-17 by Anonymous

by (mod) - Watch out: you describe an unhealthy and unsafe building addition and cesspool for multiple reasons.

To Bedroom over a cesspool,

Ick I don't know where to start joining in griping about such a snafu

Tere is not good access for maintenance or inspection, making inspection unlikely until there's a catastrophe. - see CESSPOOL SAFETY WARNINGS 

A sewage backup or sewer gas leaks can lead to a real disaster as well as less dramatic health worries. - see METHANE & SEWER GAS HAZARDS 

Where I had a home with this design, Bill Stelzenmuller had built a nice porch over collapsing septic tank. Through a big hatch cut into the floor we emptied the septic tank, filled it with rubble, sealed its top.

Then we built a real septic system outdoors, nearby and connected the house drains to it.

Smells and sewer gases traced to bathroom toilet

I have a smelly bathroom and I just replaced the wax seal and sealed the bowl, cleard any obstuction from the roof vent with a power hose and still I have a smell. what's next.? - Leo

We recently had a new septic system put in. Ever since we had it installed, we now get occasionally, a very strong sewer gas smell in our bathroom. How do we stop this odor from comming in? It never happened with the old system. - Val

I have 2 bathrooms on 2 different levels of the house. I am getting intermittent septic odor smells backinging up into both bathrooms. It happens in good weather and bad. It's not every day but when it happens it's usually for at least a week at a time.

I had the tank drained,, the toilets checked for leaky seals, the vent pipe checked for blockage. No one can diagnose the problem but it it dangerous and I need help. What other measures can I use to diagnose the problem? - Lynne

Reply:

In starting with the easy and low cost bath smell cure steps,

- check for dry traps at unused fixtures

- replace the toilet wax ring,

- check ceilings below the bathroom for signs of leakage

- listen to nearby drains when the toilet flushes - gurgling can indicater a clogged main drain or inadequate plumbing vents; if so, investigate and cure drain blockages, or in some cases, a "blockage" that occurs in the waste piping because the septic tank and drainfield are backing up

- ask your plumber to inspect the plumbing vent system for proper layout, size, routing, connections, and termination

- pressure test the vent system for leaks that may be hidden in walls, floors, ceilings

Sewage odor from nearby manhole cover - the city just drops a deodorant into the sewer

Our rent house is right next to an alley. There's a manhole there from which emanates a strong sewage smell. This is an old neighborhood with old clay pipes that we suspect are broken underground, but the city will not dig them up and replace them unless there is standing water.

The smell permeates the air outside the house and is pumped in through all ac vents into our home. Every couple of months the city will drop a "scent cake" out there, which does nothing to help. I'm 6 months pregnant and worried about any health risks this may bring to my infant. I'm at my wit's end trying to get the city's cooperation! Help! - Rachel

Reply:

Dropping a deodorant into a manhole over a sewer system is not going to correct an ongoing sewer gas leak or odor problem

You may want to contact an official in your city's health department, ask them to visit the site during an odorous time and to agree to have the problem diagnosed and corrected.

Where we removed a toilet the drain now smells - is this dangerous?

We have an upstairs toilet that leaks that we haven't used in some time.

My husband took it up four days ago and left the drain hole open. Are we in danger due to methane gas. It smells bad in that part of the house. - Stacy

Reply: seal off unused toilet drain opening

Stacy,

In particular if your home is connected to a public sewer and your house lacks a trap at the main sewer line exit point from the building, you could get a lot of sewer gas backup in the building.

Watch out: Methane in sewer gas is explosive if it reaches the right concentration. See METHANE & SEWER GAS HAZARDS

Any plumbing supplier or even home depot will sell you a toilet waste line plug that can close off that opening.

In an emergency I wrap a rag in a plastic bag and shove it into the hole - just don't push it in so far that you can't get it back out.

Horrible smell from under floor slab points to sewer

For the last 5 months we have been in this home there has been a horrible smell. I have had tampa gas, Roto Rooter, mold people, handmen, rat control, air conditioning fellow, and tampa sewer.

They all point to sewer. We have had smoke tests as well. We feel it is a breach under the slab and it is prevalent in one bathroom and the air conditioner/fan circulates it throughout the house. It was very bad on days it rained but now it is unbarable on dry days. It is getting worse and wakes us from our sleep. It can come and go but if we turn the furnace face on automatic the odor will build.

We feel the only thing left to do is scope the lines but landlord is now checking the environmental issues like the ponds in the area and the levels of the water for swamp gas. Please help us. 813 994 3391.

Reply:

Horrible,

I agree that for smells that originate in the building and given the people who have already advised you, using a camera to look for a broken sewer line makes sense.

Your observation that odors are worse when the furnace is running increases the worry of pulling dangerous sewer gass into the home.

Our ODORS GASES SMELLS, DIAGNOSIS & CURE article series (links at the ARTICLE INDEX the bottom of this article ) includes other suggestions for tracking down odors.

Horrible bleach smell from kitchen drains

I am smelling something horrible coming from the kitchen drains, our utility room and toilet area.

The smell actually took my breath away a couple of times like my throat was closing. The only smell that I can say is similar is the smell of bleach. That super strong odor. Could it be the septic? - Wendy

Reply:

A bleach smell would not be something I'd expect to find coming from a septic system. If you trust your sense of smell, I'd be looking for a chemical spill or something having been poured down the drains.

Biofilm suspected in bath tub and toilet - black slime

I rent an apartment and have noticed what I suspect to be biofilm in nature. First, the drains in the double kitchen stainless steel sink, bathroom sink, and bathtub seem to be overgrowing with black slime. I clean all areas on a regular basis with a bleach based cleanser.

My next problem concerns the toilet (which I suspect might have a biofilm issue as well?).

Every few days or so, the toilet "burps" (almost like air pressure purging back into the toilet) and then it bubbles followed by a terrible odor. If you think it is an issue concerning biofilm, is there any way I can control this myself with some type of disinfectant by pouring it down each drain. Any info you can provide would be greatly appreciated.

Reply:

Pammi,

I'm not sure what you have in mind with biofilm, but your description sounds like possibly a mold growth, more likely an algae growth. If cleaning and disinfecting are not curing that problem I suspect the water supply.

The burping toilet suggest to me a partially blocked main building drain, perhaps at some distance from the toilet and/or a building vent piping problem. I suspect that drain cleaning for blockage is in your future.

Sewer / Septic Gas Odors Fixed by Repairs FAQs

Odor problem after we added a second line to our septic tank - sewer gas now enters the house

I never noticed this problem til after the addition of a second line to our concrete tank. now sewewr air comes in the house (I believe in the kitchen area) we tried to check roof vents, had an s trap put in kitchen sinks (they had none).

I also suspect the kitchen sink is not tied in to the vent (Small high ceiling log cabin with kitchen sink away from other plumbing... but never noticed trouble before the new line to garage was added. Any ideas? - Kris 6/5/12

Reply:

Kris I may have misunderstood, but "S" traps are not used in new construction as they easily lose the water in the trap base, thus permitting sewer gases to enter the building through the fixture drain.
I suspect your sink drain is not properly nor adequately vented.

You may be able to fix the problem by installing a proper P-trap and if there is no vent line available and the local building department permits, you can install a vacuum breaker vent at the sink drain.

Cracked cast iron sewer pipe was fixed but sewer smells are lingering

Our house was listed for sale last week.
This week we noticed a crack in the cast iron sewer pipe and had it replaced by professional plumbers. A lingering miasma would certainly keep prospective buyers at bay.

We've ventilated the basement and have fans and dehumidifiers at work. We also tried vinegar solutions, but to no avail.
Any further advice would be greatly appreciated. - Vicki LeClair 6/29/12

Reply:

Vicki I hate when that happens - sewer leaks. It's possible that the lingering miasma (a sewage smell) is because there was not just a cracked pipe but sewage leakage into the building. ANd depending on the cause of the crack, don't rule out the possibility that there are other cracked sections , p0erhaps in inaccessible or hard to see areas.

Track the odor to its strongest area - if you had just the one leak that's helpful.

Then investigate where sewage water may have flowed. It may be necessary to further remove/clean wall cavities & clean flooring. If carpeting was involved, remove it.

Reader followup:

Thank you for your advice DanJoeFriedman.
Appreciate your taking the time.
We'll investigate further.

Do black copper pipes have to be replaced or should they be cleaned?

If the copper pipes are black due to long term exposure (2 years) to sewer gas, do the copper pipes affected all need to be replaced, or can they be cleaned, and if so, with what products? The source of the sewer gas has bee rectified. - Gail Rose 8/13/12

Reply:

Copper drain piping that is not actually corroded to risk leakage does not need to be replaced nor cleaned, but you should be sure that you don't have any remaining sewer gas leaks.

Rancid smell after town sewer work

Please help! I have a 115 year old home that I have lived in for 12 years. Recently, approx 6 weeks ago, the town was doing work on the sewer lines located on the street that I live on. One afternoon, end of a work day i returned home to an extremely rancid smell that permeated throughout the entire house.

The town has since inspected and said they could not find any reason that it should happen.

HERE IS WHERE IT GETS WEIRD.

The smell shows up daily and seems to be time specific each day from 3:30 pm to around 5:30 pm?!

In addition to the towns inspection, we have had two different plumbers inspect from top to bottom. Any suggestions would be sincerely appreciated. - Anonymous 8/19/12

Reply:

Try the diagnostic suggestions at ODOR DIAGNOSIS CHECKLIST, PROCEDURE where you'll see that we suggest looking for things to correlate with smells that appear at particular times or seasons, such as

- operation of nearby businesses or activities

- operation of equipment

Sewer / Septic Gas Odor Mistakes: smells not from Sewer or Septic FAQs

Sulphur odor in water, filter fixed it, then sewer gas odors.

I am looking for some advice. We have just moved in a brand new home. At first we could smell a strong sulphur odor in our water. We had a centaur filter put in, which took the smell away immediately.

I then noticed sewer gas smell mainly in our 2nd floor laundry room, but also the 1st floor mudroom (utility sink.) I was told to add water to the sinks and floor drains and mineral oil to the floor drains as well. I did this and we still have the sewer gas odor, especially after I do laundry.

My dryer which was working perfectly before the move, now takes 3 cycles to dry a load of clothes. It is after running it, that the smell worsens. FYI the dryer is not vented to the outside wall, but apparently into the stack and up through the roof through a static vent. I would love some ideas as to what it could be as we are now having burning noses and throats and headaches. Thanks so much in advance. - Heather 9/12/12

Reply:

Heather:

Let's separate things to not get too confused. Odors in the water supply - if that's where they are coming from, won't affect how long it takes a clothes dryer to dry stuff. But odors in the water do need to be diagnosed and most likely corrected. There are treatment systems for sulphur if that's the problem.

Separately, investigate the dryer vent system for length, bends, blockage - as longer dry time also can be an indication of a FIRE HAZARD as when a dryer has trouble venting it not only takes longer to dry the clothes but it also runs hotter.

Reader follow-up:

An update. The plumbers came and did a smoke drop test. There were no evident leaks in there. The builder sent out someone the next day, who found the dryer vent on the roof was totally blocked with a mat of lint.

He removed that and the wire mesh that was left in place. They raised the vent stack to over 3 feet. I let the house "air out" for 3 days then decided yesterday, that we needed to try out the AC, as our symptoms increase dramatically when it is on. Within 10 minutes of it being on, we started again, with burning eyes and throat with headache.

The dog even had clear drainage from his nose. Today the HVAC technician was here to look at both the unit in the attic and the one in the basement. He thought that it could be the oil that is applied at the factory, that was not burned off. He told me to run the heat for as long as I could, which I did.

We are getting the vents and units cleaned tomorrow. He then told me to run the AC after and see if we continued to have symptoms. Everything I have read points me to the fact that we are inhaling either VOCs or formaldehyde. The house is brand new, and I would not expect "sick building syndrome" in a brand new home.

I have never reacted this way to anything before. I am at a loss. Also, there is no attic fan.

Do you think we could benefit from having one placed? Thank you so much for the help. - Heather

Reply:

Heather, based upon your comments - you are a good candidate for an air quality test. An environmental testing co. could take samples from your home and have them analyzed for gas levels . turnaround would be a week or so and would identify higher than standard levels in you home.

Possible sources (other than those you've mentioned) are : paint off gassing, hardwood floor finish, carpet fibers, cabinet plywood or particle board, particle board carpet base, among others. Any new home will have a period of off gassing from finish materials . higher indoor temperatures accelerate the gassing effects. - DF

Comment from reader NCBuilder:

Heather, your builder should also be able to provide EPA data sheets from manufacturers of finish materials used in your home : paints, varnishes, floor finishes, catalyzed laquer (cabinets), carpet fibers, etc. These would be a big help if you indeed go the air quality sampling route.

Reply:

Thanks NCBuilder - Ed.

Sewer / Septic Gas Odors in Bathrooms FAQs

Foul smell in bathrooms and main drain

My home has a foul smell. In both bathrooms, sinks, and main drain in the basement. I noticed today that the main waste stack has two 90 degrees on it, is that ok?

Could that be contributing to my smell? I live in St. Louis, MO - Mary 10/30/2012

Reply:

If the plumbing vent (main waste stack) is unchanged, that is if that double bend has always been present and the odors are new, I doubt that it's the problem. But I'd agree that a blocked or leaky plumbing vent system is often an odor source.

Sewer / Septic Gas Odors at Appliances, Dishwashers, Washing Machines FAQs

Sewer gases at sinks and smelly dishwasher

I have two problems. One: Sewer gases smells are coming from my bathroom sinks, one upstairs and one downstairs. It is not all the time but at least 80% of the time. I my landlord but is just said that this is a problems that lots of people have and nothing is wrong. He never actually investigated.

The secoond problem: My dishwasher is emitting some type of datk gummy residue all over my dishes. In addition, I also notice a dark powder like substance on the outside of the dryer at the bottom.

My landlord said that these problems come from food particles left on dishes. I always use a brush to wash my dishes and I know that this is not the cause. It appears that there is a build up of some kind and then it is all over everthing. I wonder if the two problems are related and if this is residue from the sewer.

I am a senior citizen and recently my daughter and her 8 month old baby living here. I am concerned for our safety. I have some medical issues that never occuted before I moved her a few years ago. such as extreme fatigue and some times headaches. Could you pleasae give some advise. How can I get these things tested without it being too costly? - Barbara 12/1/12

Reply:

Your landlord is wrong that sewer gases are harmless; the risks are of a methane or hydrogen suflide gas explosion, and from chronic exposure there are potential health effects (citations are in the references at the end of this article).

See METHANE & SEWER GAS HAZARDS

While it's common to detect slight odors and low gas levels right at sink drains if you are smelling those odors in the occupied space, that is not normal and needs to be investigated and corrected.

Sewer / Septic Gas Odors at Mobile Homes & Trailers FAQs

What to do about a trailer home bathroom that smells like a porta-potty

My bathroom smells like one of them porter potties you find at a constuction site. You can smell all through my trailer but, strongly in bathroom. What can I do to fix this horriable odor On 2022-02-05 by Jennifer -

by Inspectapedia Com Moderator (mod) - check for leaks around toilet base then see this odor diagnostic article

@Jennifer,

Check first for leaks around the toilet base, and confirm that the toilet is securely mounted to the floor. If you don't suspect a problem there, see

INDOOR SEPTIC ODOR, OUTDOOR CAUSES https://inspectapedia.com/odor_diagnosis/Sewer_Odors_Fixture_vs_Drain.php#SewerOdorsa

and

SEWER GAS ODORS - topic home,

where we suggest a series of inspection and diagnostic steps to track down the smell source.

Whenever the kitchen sink is used the trailer home smells like raw sewage

Just bought a new trailer. Bathroom and hallway floor were replaced cause of leaky toilet.

New seals put on toilet.

Now whenever the kitchen sink is used, the entire house smells like raw sewage.

But when the bathroom get used in any way there is no smell. What could it be? On 2020-07-04 by Sam

by (mod) - Look for plumbing vent pipe missing, blocked, leaky and investigate extent of prior flooding

Sam

If sewage ran on the floor surface it quite possibly leaked under a wall partitions and possibly into the wall cavity below.

Just fixing the leak and cleaning the surface of the floor risks leaving sewage contaminant in place.

You may need to access the floor from below the home, inspect for leak signs and completely remove any insulation that was wet before then cleaning and sanitizing the exposed surfaces. When you've done that and everything is dry you can re insulate.

You might also need to pull off the bottom 6in of drywall on Floors around the bathroom to see if sewage effluent leaked into and contaminated the wall cavity. Start with a small test opening and that will tell you if you need to go further. Make your test opening in the most suspect place.

Sewer / Septic Gas Odors Using Chemicals or Deodorants FAQs

Using a deodorant to "cure" hydrogen sulfide smell in sewer line?

I have hydrogen sulphide smell in my sewer line and have identified but have yet to see anyone's help to remove the problem.. what do I put in my sewer drains and lines. (Apr 21, 2014) don

Reply: sewer line deodorants & additvies?

Don,

I don't think that ANY additive, chemical, or treatment poured into the sewer drains and lines is likely to be effective, and it may be harmful to the drainfield and will be illegal in many jurisdictions if you are connected to a private septic system.

Rather we want to track down the odor cause and fix that. Examples are defects in the plumbing vent system, leaks in the sewer piping, or a backing-up main building drain, or if you are connected to a private septic system, a backing up or clogged septic system.

Don said

thanks for your response. I have a lagoon system, installed a new mobile home in dec 2013, the odor started about mid Jan while wife was doing laundry, I understood bleach would clear up pipes but no luck.

There is a strong smell from vent pipes on roof, strong smell around out side seems to come from vent lines.

I have replaced all vent line check valves to P traps but no change in odor.

When washing machine is running seems to be worse. If it's the machine how do I fix it? Thanks for any input as odor is quite strong at times. don

Reply:

We discuss lagoon septic systems at inspectapedia.com/septic/Lagoon-Septic-Systems.php - take a look.

Some odors are normal around a septic lagoon treatment area, but others are not, as you'll see in that article.

Bleach will not fix anything in this case and if used in quantity it may harm the septic system.

Don repllied

After much searching you can rid the hydrogen suphur smell, try using hydrogen peroxide. I do a week ago and no smell left. I put a bottle in each drain, the washing machine and each vent line on the roof. so my original question is answered and hope this helps anyone else with this problem.

Warning by Mod

Watch out: Don's advice is dangerous. It treats the smell symptom not the cause. If sewer gas is entering a building there is risk of an explosion.

Sewer / Septic Gas Odor Health Effects FAQs

Smells in mobile home traced to sewer line not connected: seweage just dumped under the home!

II have rented this moble home for 5 months now and my 22 month old baby and the rest of the family have been sick for a while. Even after cleaning really good.

About a week ago i had a pipe freeze and bust ao called the plumber while fixing the busted pipe he said that my drain pipe was not hooked up to septic but had been draining under the house.

The pipe has been fixed but landlords have not had anyone come clean under house. Is that something to worry about? - S Susan 1/29/2013

Reply: Watch out: serious health risks from open sewage

Susan,

Without inspecting and testing we don't actually know what hazards are present in your home nor if the unsanitary conditions under the home are showing up indoors. But nevertheless, you are describing an unhealthy condition that almost surely violates local building and plumbing codes in your area.

Watch out: bacterial hazards, sewer gas hazards, methane and hydrogen sulfide gas hazards are all potential health hazards and where those gases accumulate indoors they can even be an explosion hazard. Notify your landlord in writing of these conditions and ask for immediate repair and also cleaning and sanitizing at your home.

Worried about septic tank odors and health effects

Hi I am worried about my sons health we have a garage built in to a room when we moved in well the owners had a septic tank in the back.

We have these horrible smells throughout the day. I was just reading and it contains methane gases.

What is the best way to fix the problems cause I am worried about the gaes and my sons health (May 27, 2014) Megan

Reply:

Megan there ought not be sewer gases invading the home from a septic tank; the odor may indicate that there is a backup at the tank, leaks at the tank, or a failing drainfield. I'd try to track own the odor more accurately.

If the septic tank is in use the system will need diagnosis & possibly repair.

if the septic system is not in use it needs to be emptied, cleaned, and filled-in.

Can a sewer gas smell or rotten egg smell affect my health?

I have been smelling a rotten egg smell in my apartment for about 2 years; is there any connections to health concerns such as thyroid and autoimmune symptoms? On 2015-02-26 by Sheila E

by (mod) - possibly, check with hour doctor first

The health question may be best taken to your doctor.

Rotten egg smells are usually sulphur in the water supply.

Take a look at this explanatory article

and for exposure effects for H2S (hydrogen sulfide)

see HYDROGEN SULFIDE GAS 

Sewer / Septic Gas Odors When Water is Run or Fixtures Used FAQs

Sewage smells when water runs in the bath fixtures

My bathroom sink (and, recently, my bathtub) smells like sewer whenever I run the water, be it hot or cold. It doesn't smell like rotten eggs; more like poo. There is no gurgling sound and both drain properly. The sink is new, as well as the P trap. I opened the P trap and the water smells like sewer, like, really bad. The washer drain, also located in the bathroom, is fine, as well as the kitchen sink.

I replaced the bathroom sink for two reasons: this odor and the fact that it was old, hoping this will solve the problem. It didn't. When I replaced the sink I used an auger to clean the drain as well as I could. There was no abnormal smell coming from the drain at that time.

This puzzles me because I don't understand why it doesn't smell when the p-trap and the other components are removed but does when they're installed... Also, it doesn't smell when the water is turned off and it is present regardless of the weather or season.

I live in a city so my water drains into the city main. Also, I live on the top floor of a duplex. The first floor doesn't have this issue. I suspected it might be the toilet that sucks the water from the p trap when i flush it but it's not that. Even if I don't use the toilet, the odor is present. Strangely, the toilet doesn't smell when I flush it. Any possible explanation? Thanks! (July 5, 2014) Val

Reply:

Val

Unfortunately if sewer gases are backing up through a sink drain, replacing the drain and trap are unlikely to fix the problem. One needs to find the cause such as improper venting that tends to cause water to siphon out of a trap.

I suspect that when you run water, the draining water is displacing sewer gases in the piping that should be vented above the roof but instead are entering the drain system.

Sewer / Septic Gas Odors Related to Excavation or Plumbing Work FAQs

Sewer odors after new sewer line installed

We had a new lateral line dug because our original two were saturated and now we have a sewer smell in one bathroom daily and once in the whole house. Our plumber crawled under the house and didn't see any leaks.

We had just had the tank pumped out and no one can figure it out. Help (Aug 6, 2014) Paula

Reply:

Paula

If you are sure that the smell problem originated with the excavation and drainfield line work then I'd be looking for an error in the installation that blocked a drainfield line, D-box, etc.

Have your septic contractor open and inspect the septic tank and D-box for signs of sewage effluent backup.

Also check the obvious and unrelated causes: a loose toilet, bad wax ring seal, improper venting.

See details at SEPTIC FAILURE SIGNS 

Sewer / Septic Gas Odors at the Septic Tank FAQs

Leaks & odors at the septic tank lid - we tried adding dirt

We have used dirt on top, plastic when lid is reset to try to act as a gasket, but nothing works. Any suggestions? (Oct 26, 2014) septic leaks thru lid of old cement 1000 gallon tank. said:

Reply:

Watch out: what you describe may be unsafe if the septic tank lid is not properly selected and installed - someone falling into the septic tank usually dies.

Ask your plumber about signs of a backup at the septic tank or about installing a septic tank vent in an appropriate area.

Typically the plastic lid meets a plastic rim on a septic tank riser and if both surfaces are clean and the lid is screwed down tightly it should be secure and odor free.

Can a bad septic tank baffle cause sewer gas to come back inside the house?

Can a bad baffle cause sewer gas to come back inside the house? On 2019-11-04 by Bev

by (mod) - directly, no, indirectly, yes

Bev

That's an interesting question; in general I'd say no, with some explanation needed:

A septic tank baffle defect ought not itself be responsible for sewer gas odors back in the house in that the baffle is NOT a gas nor water seal between the house and the septic tank; rather the inlet baffle's job is to keep septic tank floating scum and grease from backing up into the sewer line between house and tank - where it'd cause a clog.

So how would sewer gases pass back from a septic tank into a building?

1. There is no main sewer line trap at the house exit (in fact this is common)

2. The house main plumbing vent system is improperly installed, damaged, leaky, or clogged

and/or

3. Venting defects are causing siphonage of traps at sinks, showers, tubs, thus letting sewer gases into the building at those locations.

Of course there are other sources of sewer gas odors as you can read above on this page and in other articles in this series.

To read details please see SEPTIC TANK BAFFLES 

Odors after septic tank pumped

After having my septic tank empty I have a strong odor coming up from the bathroom shower when you run water (May 28, 2014) Dee

Reply:

Sounds as if there might be dry traps in other fixtures or a leaky vent piping. Cleaning a septic tank ought not create an odor problem in the building.