Sewer gas odor in apartment--8 months & counting

In buildings that old chances are your sewerage pipe is cast-iron or lead. It is possible that, in attempting to fix the problem, the landlord has cracked the pipe or broke the seal between the pipe and the next pipe segment. Back then, molten lead was poured in the joint between sections, and this could have become dislodged, allowing gas to escape.

But what surprises me is that the kitchen sink has an odor as well. The P-trap under the sink is there to prevent sewer gas from coming back up through the drain. Is there, in fact, a P-trap under your kitchen sink, and is there water in it (surely)?

either that, or an open vent. A lot of amateur plumbers do not know what the vent is for and think it is for a future sink, and leave it open.

you need someone inspect the entire drain stack to find this

Check to be sure that the air vent in not obstructed. Remember, it you flush a pail of water down, you have to vent a pail of air up.. (outside)

Is the sink on the other side of the wall from the bathroom? The question is to first confirm that they are both on the same stack.

Does the apartment above or below also smell the odors?

Are there any leaks into the basement, dripping down the waste line that might indicate a cracked joint at a drainage connection? I would think not because that would be an obvious clue, but you have to ask.

Having set many cast iron joints, they don't come apart.

If the vent line, which may or may not have been galvanized pipe, may have rusted through at or near a joint and perhaps jarred by the repair have crumbled.

If the smells are localized, apartments above and below report no odors, opening the wall behind the kitchen sink cabinet may provide clues before more extensive destructive inspection is required.

If this building was built on a garbage dump fill area then gas odor can come from the ground and it is waiting for an explosion. As date for building construction is very old, the very likely cause is within the building and nor beneath it.

If this building was built on a garbage dump fill area then gas odor can come from the ground and it is waiting for an explosion. As date for building construction is very old, the very likely cause is within the building and nor beneath it.

Not likely to be the problem if the bldg. is as old as he says. It was rare to find a dedicated dump that was recycled for building in those years. Folks had pride in those days and a bldg built on a garbage dump would have been looked down upon.

It is possible that during the repair -- the WAX RING was improperly installed or didn't seat --- sometimes on retrofits for old bldgs it takes two wax rings to seal. Been there -- Done that. Solved the problem.

If the wax ring was distorted during installation or if the toilet flange was set too low or new floor was set on top of old, increasing the space betweem the toilet and flange then a leaky wax ring installation might result. However in that case usually thjere would be water leakage as well which would have shown up in the basement at the bottom of the stack or as a wet spot on the ceiling of the bathroom below. The landlord replaced the toilet as one remedy and if the wax ring was not compressed and stuck to both surfaces, the landlord should have noticed the issue since he was looking for a cause to a problem. Of couae "should have" may be part of the problem. Bottom line, as you suggested a second or extra thick wax ring should solve that.

Venting or incorrect trap installation could be the problem. All plumbing fittings connected directly to any sewerage or waste stack should be trapped. The sewerage or waste stack should be vented. A stack not vented can cause a siphoning effect which pulls all the trapped water out of smaller traps such as basin, bath, sink or shower traps. This could occur when a toilet is flushed. Interconnecting waste pipes from basins, baths and showers can also cause this effect. Secondly, if the vent pipe is left open on the outside of the building below a window for example, the smells could be emanating from there. A one way vent valve would solve that problem.

Hi rae,

Welcome to CR4 I hope you enjoy and get as much out of participating as I do.

My brother had a similar problem and ended spent a small fortune trying to solve it over nearly a decade. He was not happy when I informed him what was wrong and fixed it in less than a minute.

One of the things that often gets overlooked and forgotten about is the drain or waste trap in the floor. Like all drainage points it needs to be isolated with an S trap that is full of water to prevent sewer gas from being escaping. What happens is that because the trap is seldom used the water in it can dry out and this allows sewer gas to vent into the atmosphere. Another thing that happens is that inexperienced plumbers forget to charge it with water in the first place so it never blocks the sewer gas from day one.

Don't panic, it costs nothing and is easy to fix. All you need to do it take a bucket of water and tip it down the waste trap in the floor. You will also need to do this roughly every month or so otherwise the water in the S trap will go stagnant and can dry up.

As Snakers pointed out another problem is the air vent. When a toilet is flushed above you it both forces a slug of air along the pipe in front of it and sucks air along behind this. If there is no where for the air that is being pushed along in front of the waste water it can force its way back up past the S traps and escape into the room. This can easily be checked as one of the symptoms will be a gurgling or bubbling sound coming from things like drain in the sink.

There are a myriad of traps that amateur plumbers can fall into and most of them will get caught by at least one of them. My money is on a dry S trap that has either dried out or was never charged with water in the first place.

Dear Mark

You have good knowledge of plumbing work. My doctor daughter in UK is better than me and she fixes her plumbing work herself with tools she can get from supper markets.

In India it is all done by specialized people at very low cost and no one seriously tries to learn so they know nothing good to the level you all know. I admit that now.

My plumber is very friendly and like a teacher. I was also taught small things by my plumber and he made some water traps in between flush pipes for the toilet and hand wash sinks. I did not know the importance but looks that wherever water gets dried up, the smell comes from the gutter back into the zone. Hence, water need to be there all the time and better to flush once a day. Those U turns and extra pipes are good to hold water and form gas lock. For people who are away for long and on their return this may be a serious problem, so first thing to do in the house is to flush some water in every possible sink, toilet and drainage point.

Just curious...what makes you think there is a drain in the floor? Bathrooms will almost never have drains in the floor unless the shower does not have a sill to keep water in the shower. Of course if there is a drain in the floor you may be right in your diagnosis although sewer gas smells around the kitchen sink would seem to indicate the issue is not limited to a bathroom floor drain. If the gases were going from the bathroom to the kitchen throught the bathroom door, the whole apartment would stink, I would think.

Hi sail4evr,

"Just curious...what makes you think there is a drain in the floor?"

It depends on the local rules and regulations but in Australia it is the norm to have a separate floor drainage trap in bathrooms and laundries. In some places it is actually compulsory. Considering the amount of damage they can avert the added expense of adding one when the plumbing is first installed makes them a really good idea.

Hi Shyam,

When I was a cadet control systems engineer you had to spend at least 3 years in the field designing, installing and commissioning just about any type of control system in existence. Back then pneumatic control systems were commonplace and you needed to know all about pneumatic plumbing and be handy with an oxy-acetylene torch. Domestic plumbing is no where near as critical as pneumatic plumbing and so if you know what you are doing with pneumatics then the rest is really a breeze.

You are one up to me. I learnt only fire fighting equipment use, x-ray film processing and some useless emergency handling drills and never had a chance to do plumbing. I think all should learn these things first. I also like vehicle repair mechanics, radio repair mechanics, and those large earth work mechanics, road builders, miners, canal diggers, farmers, sheep wool cutters, weavers, and many more out there doing things like an experts. I can only do small things like electronics here and there. What a waste of life indeed. I like every working man on the street and I sit day in day out in AC room without knowing anything about the world. It is shame indeed.

Hi Masu,

The company I work for has floor drains that needed to be filled every month or so. I finally got tired of lugging pails of water around (about 20 drains on the production floor) so I went out and bought a few liters of vegetable oil as I figured the oil wouldn't evaporate as quickly. It's been 3 years and I haven't heard a complaint yet. Worked so well that I did the same thing at home for the drain beneath the hot water tank (for the overflow) which is almost never used. Worked there too !!

give it a try...

regards,

Rick.

.

You were draining the oil in place of water. Looks very expensive solution. Even once the water is flushed, the oil trap is gone so you do it again?

Many floor drains are only there for exceptional events. So there isn't a regular input of water. That is why they dry out. Equally, if you top them up with oil that doesn't evaporate, the oil will simply stay in place.

Even when the drains are used occasionally, the oil will stay floating. So long as the flow is slow, the oil on the inlet side will stay in position; then, depending on the environment, that may be enough to prevent the water evaporating as well.

It is sure very innovative idea. I only afraid of the cost of the oil involved. Perhaps some waste oil may be OK to dispose off in this way and may also prevent mosquitoes to habitat in the drains. I think it is good thinking. Even tickle of oil may also work in regular drains.

I'm assuming that it was a light, high-temperature edible vegetable oil - that would cause minimal issues - though it might not always be legal.

Oh yeah, we are not talking about gulf oil and petrol down the drain. It will smell worst and may also send signal to fire brigade.

From your description of the history, it does indeed sound most likely that something was disturbed under the floor. It is possible the building has a line of joists running between the kitchen and the bathroom; it would be quite usual to arrange things that way, and the gaps around other pipework would explain the smell appearing specifically in those two places.

Timing - night and morning are when you and your neighbours will most likely be using their plumbing, which will disturb things. Not knowing the layout of your flat, I'd be curious as to whether there is an internal downpipe in a cavity between the kitchen and the lavatory - or whether there is external "ventilation" in both rooms opening onto the same downpipe or venting pipe.

Given the disturbance involved in taking up the floor (yet?) again, I would also inspect for other things first. For example, is there drainage for dishwasher and/or washing machine anywhere near where the smell appears and disappears most suddenly? It is surprising how often they are fitted without traps - even by "professionals" (taking short cuts?).

Thank you for the info. There's no dishwasher or anything else in the apartment but a bathtub, toilet and sink, and then the kitchen sink on the other side of the bathroom wall. I would imagine that the kitchen sink and bathroom share the same vent. Do you think the vent pipe would be cast iron in a 1925 building? If he cracked a seal or something when putting in the new floor and toilet, how would we find out? Thank you, Rae

Vent pipes in the 1920s were very commonly cast iron. (They also used ceramics, but usually only where they wanted the pipe to look like a chimney).

If it is the vent pipe, the problem would be worse by an open window. Having the window in one room closed and in the other open might give you a clue. Another trick (if noone objects) could be to wrap an extended section of the vent pipe above and below your window in cling-wrap film and see if things improve.

As regards locating a cracked joint - although I've never needed to do this, Masu's suggestion to inject smoke into the system sounds as good as any - but you'll need to use proper equipment if it is to be safe (smouldering materials can easily ignite sewage gas) - and open up underneath one of the traps - or better still, inject on one occasion in the kitchen and (considerably separated in time) on another in the bathroom, so that any smoke leaking from your source doesn't cause confusion. (That probably won't show up the vent pipe, because the join can be quite distant, and there may even be additional traps in the way. You might be able to do this separately if you can gain access to the top of the pipe)

Have him scope all the pipes with a camera, and look for leaks.

Dear Repliers, thank you for all the handy information. From what I'm reading and experiencing, I suspect the vent is the likely problem. The odor is in both the kitchen and the bathroom at the same time, and they are back to back and share a wall and the same plumbing stack. The kitchen sink does have a U-pipe trap, and we ran water for awhile the other day to try to make certain it was full. How do you know is the sink trap is holding water and working? If the vent is not working, will the sewer gas enter the building even if the traps are working? We had another big stink episode today, and I hadn't used any facilities in the kitchen or bath for several hours. I've relayed this info to the landlord. There's no floor drain in this second storey apartment. Would the other apartments on this plumbing line be stinking too if the problem were the vent? Does each apartment have its own line to the main vent line and perhaps only mine is blocked? The landlord behaves as though if no one else in the building is smelling sewer gas, it must not really be a problem. Thank you, Rae

there is one possible problem. Birds have been known to build nests in the roof vent of stacks. You are supposedm to have a bird proof screen on them and they point down in a U r have some other type of cap that prevents rain and birds but allows gasses to vent. This filling up with fumes make me suspect such an external plug, or lack of the vent totally. SInce this came 8 months ago, birds = strong candidate. Can you examine the roof vent from a vantage point? or must you go up?

I doubt it's bird nests, if only because this problem began when he tore the floor up and put in the new toilet. Also, other people in the building would be affected if the whole vent was plugged up. But I think you're right that the vent is involved. How would the vents for multiple toilets in apartments one above another work? Would the vent pipe be cast iron too in a 1925 building?

It is very unusual for a bathroom not to have a floor drain? perhaps it was removed or disconnected in the renovations? also, baths and basins around 1920 often had overflow slots in them so they couldnt overflow. perhaps the smell is passing through them.?

I'm thinking perhaps he connected the vent to the old floor drain pickup and blocked the old vent pickup by mistake. This may cause the gas to bubble back though the S bends in the other pipes when the toilet is flushed.

Perhaps as a last resort he might call a licenced plumber!

Leak wise, in temperate climates the plumbing ran down the outside walls, making inspection for leaks easy. replaced pipes can often be tracked by following the marks on the wall or the trail of mounting spike/bolt holes.

finally, in the short term embalming perfumes will disguise ANY smell! and it doesn't smell much itself. OR tip about 20 lb of pool clorine down the sink to sterilise the pipes!

One technique I have seen used to both prove and find where and how sewer gas is getting from the system is to use a smoke generator. The idea is to connect the smoke generator so that the isolated portion of the plumbing fills up with smoke. You then go to the furthest point on the line and start flushing toilets and draining sinks moving sequentially along the drainage line till you replicate the problem.

If everything is working correctly the only place you should see any smoke is the top of the air vent. If however, there is a problem you should be able to easily see where the smoke is coming from.

It will at least categorically show that there is a problem and that sewer gas is getting into you apartment and that puts the onus on the building owner to get the problem fixed.

Sewer gas is something that should not be taken lightly as it is not just an unpleasant smell. It can be toxic and a fire hazard and can carry virus particles and live bacteria in suspended droplets. It may also indicate that there is a leak and therefore contaminated material soaking into parts of the building structure. Very nasty and dangerous.

I am not 100% sure about the idea of flushing 10 Kg of pool chlorine down the drain, it will sterilize everything but it dose produce chlorine gas which is highly toxic. Since sewer gas it getting back into your apartment you will more than likely get chlorine gas being released into you apartment and that is a definite NO NO!

A better solution is to use sodium hydroxide NaOH. It will also kill everything and clean the drains out at the same time. The easiest way is to use the commercially dish washing machine powder and flush a few cups of it down the toilet. Commercial dish washing machine powder is pretty much straight NaOH so make sure you wear gloves and don't let it come in contact with your skin.

FYI Sodium Hydroxide is standard household drain cleaner. Alternately, Professional Drain Cleaners are available which are stronger and will remove many more obstructions than sodium hydroxide, these are typically composed of strong sulfuric acid. Both the sodium hydroxide and sulfuric acid will only sterilize as long as they have extremely high concentrations (pH very high/low) neither are inherently toxic to bacteria , and many bacteria can survive in pHs that will burn you. Sodium hypochlorite will not produce alot of chlorine gas unless exposed to a strong acid, and it is a good anti bacterial agent at a few hundred parts per million. However, it has a lond life and degrades slowly, so huge quantities of this into a sewer can be a headache for the treatment plant if not neutralized. Hydrogen peroxide can be purchased at 30 %, is extremely effective at disinfecting down to like 500 ppm, and will degrade readily before reaching a treatment plant. The hypochlorite and sulfuric acid will have distinctive noxiuos odors themselves that may be used to locate problems, or may not be something you want. Sodium Hydroxide, Sulfuric Acid and Hydrogen Peroxide are all very dangerous when handling at the concentrations purchased. Bleach not very dangerous. As well low concentrations of Hydrogen Peroxide can be purchased that are not dangerous, like 3 to 5%.

What are you talking about? Floor drains are very rare in older apartments in most countries, as they are only of use if the floor is tiled, and is is expensive to make a good tiled surface above floorboards.
It is highly unlikely, but possible, that you may be right about the overflow slot causing a problem; most basin overflows share the same outflow, and therefore the same trap as the main plughole; however, some designs of basins and sinks (designed for heavy-duty situations where the trap could become blocked) had separate outlets for the overflow, and these could be externally plumbed below the trap. Worth a check.

In my current home and all places I have previously lived in the US, there is no cap or screen on the stack vent pipe. It emerges straight up through the roof. From my experience, the vent is a straight connection between the waste drain under the house and the roof outlet, running in the wall or a chase.

It's worth making the effort to talk to your neighbours in the apartments immediately above and below you. They mightn't prove to be the monsters you fear either...

Rae,

This just happens to be my line of work. Unfortunately, without the ability to be on site and poke around, it's next to impossible to accurately diagnose your particular problem. You have been given several good suggestions as to where to start, but it's going to take a good plumber coming out and probably doing some invasive investigation to find and repair the problem. You could maybe pull the toilet up (it's only two bolts and the water supply that need disconnected) and check to make sure the flange is sound. Does the toilet wobble any or is it firmly fixed to the floor? If it's loose at all, then the flange may be cracked and leaking. Where specifically is the odor in the kitchen coming from, up out of the sink drain or under the sink, or just anywhere in the room?

Just to add my pennys worth. I am a heating & air-con contractor. a number of years ago a nursing home customer of mine had a similar problem with elusive sewerage odours. that first occurred 3 months after some renovation work was completed. It took some finding but I was able to trace it back to a plumbing system vent that the builders plumber had forgotten to extend clear of the building roofline. In fact it terminated just at the wall top plate in a cupboard. The problem was worst in the morning and evening when the bathrooms were getting most use.

happy tracing

regards

Coben

Simple Solution

Call in the city inspector. The landlord has a legal obligation to provide living arrangements that meet legal codes.

the sewer can be cnverted to cooking gas as biogas with my research

I would think to have the vent pipe expected. It may be clogged. Before the landlord started the plumbing repairs it may have been venting into the walls thru the a crack.

now may be coming back up thru the traps. In the early AM and in the evening is when you would smell it most as most people prepare for work or come home and clean up for dinner and the evening.

I've had excellent results with leaking connections and disconnected vents by pouring cheap Clorox down the sink/bathtub drains, toilets, and roof vents. A strong odor of Clorox will tell you where the leak or disconnected is located. I've never had to use more than 6-10 gallons.

The sewage (and drainage) system must be checked, repaired and cleaned.

The leasing contract will determine the person responsible for the costs.

Outside reasons must also be investigated.

In one instance the smell continued after the system was replaced. A dove (pigeon) had a nest with eggs on a ledge outside the bathroom and was killed. The rotting eggs and Pooh was the real reason for the smell.

Have you seen the old lady that lives next-door lately?

That is also a gruesome possibility.

A old lady was picking up every chicken in a supermarket and smelled it below to determine if it is fresh. The irritated shop attendant then ask her if she think she would pass the test.