Hi


Our master bathroom's shower has suddenly began to stink... like sewer gas or rotten eggs. Here are the steps I have taken:

1)Cleaned the drain with a brush and cleaner so the drain and pipe are spotless. There was a TON of black gunk on it... but it had been that way for 2 years and we use the shower about 2-3 times a day and it never smelled.
2)Snaked the drain to about 20feet and nothing was down there.
3)Confirmed that the sink and toilet in the same master bath do NOT smell.
4)The smell only comes from the shower drain when about 5 minutes into a shower until the end of the shower.
5)The smell does not exist hours later after the shower... again, only when showering and only about 5 minutes into the shower does it appear.
6)The drain has water so I don't think the water evaporated or anything like that... we use the shower 2-3 times a day every day.
7)We have a septic tank/leaching field... not a sewer.
8)It is not the water that smells.
9)The shower itself is pretty clean... doubt that it's the floor or walls of the inside of the shower.
10)This smell only appears from this 1 shower... all toilets, sinks, and other showers in house smell just fine (and are used far far less frequently).
11)I have tried filling the shower with about 5 gallons of water, then letting it all go down the drain suddenly in order to push anything out of the way that might be far down the pipe.

The only thing left for me to try (I think) is to pour 1 quart of water into the drain in case somehow the trap evaporated... but wouldn't #11 above have helped that?


If there is something you wish for me to take apart and check, do you have a schematic of a typical shower/shower drain so I know what exact pieces you are talking about? I am not sure if this is a vent issue and wouldn't go up on the roof looking (I am afraid of heights)... but I would think other plumbing items in the house would lead to that vent... so if it was a vent problem, wouldn't the sink and toilet in the master bath also smell?

Since this smell appeared very suddenly (and I've cleaned the drain very well and still the problem persists) I would think this is something other than a biofilm pipe... unless the film is far down the drain/pipe where I cannot reach with a scrubbie and chemicals.

Thanks so much in advance for your help!

-Eric

You should not worry about an evaporated trap if the shower is used 2-3 times per day. The only thing I would add to your list of things to try would be to rid the vent stack from the roof. Your traps could be siphoning as they drain due to a clogged vent.

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Originally Posted by ballengerb1

You should not worry about an evaporated trap if the shower is used 2-3 times per day. The only thing I would add to your list of things to try would be to rid the vent stack from the roof. Your traps could be siphoning as they drain due to a clogged vent.

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Hi... thanks for the reply. Can you please elaborate on ridding the vent stack comment? I will have to send a friend up there.

Should he use a stick or particular device? Push or pull? How long of a stick/device should he shove down the vent? Etc. I'm really a newbie at this and have absolutely no idea what the vents look like or how they work... and how rough/gentle we need to be with them. Do you or anyone here have a diagram/schematic of how most showers/vents/pipes are laid out?

Thanks!

-Eric

p.s. I am trying a few scoops of Oxyclean powder right now... so far I can't tell if it is helping... dumped 1 scoop in, let it sit for 30 minutes... then flushed with warm and hot water for about 5 minutes... then put in another scoop and also sprinkled some on a scrubby brush and scrubbed the clean drain pipe. I can smell the odor when using the scrubby brush...


Also... is it possible a clogged roof vent would cause this problem? I went to my attic and found the vent that goes to the roof so I know where to look. It seems my master bathroom is vented to that 1 vent while the other bathrooms in the house (on the other side of our house actually) are vented on a 2nd vent.

Maybe some leaves blew into the vent?. and thus is keeping the smelly air from rising out of the vent?. and thus backing it up into our master shower? But that's odd that we don't smell the odor from the toilet or sink... unless we need to use those much more extensively in order to produce the odor. Ideas?

Most websites state putting a garden hose down the vent and turning on the water... but forcefully pushing a birds nest or other junk DOWN a vent doesn't seem like a good idea to me... unless I am wrong. Why in the world would I want to push something further down a pipe... why not snake it? Unless it's impractical.

We ran into this situation before. It was bacteria growth inside the drain. It had very distinctive odor to it...

Look inside with flash light and see if you have white, slimy looking substance on walls of the drain inlet and pipe - before pipe reaches water in trap. Come back to let me know what you've found out . Thanks. Milo

Do any of your traps "gurgle" when something's draining? A vent draws air in to reduce suction caused be a discharge. A blocked vent could suction the water right out of the shower trap causing a odor. Unless your lavatory vent runs directly up through the roof it's revented back in the attic and must be cut open to snake.
In the mean time this may be of interest.
Most bad odors in bathroom drains come from rotting hair mixed with grease from the soap. Try this. Remove the two screws holding the strainer. (TIP; put the screws in the soap dish before they get lost down the drain.) Shine a light down there and with a bent coathanger fish out any hair that may be hiding down there. Then pour a 1/2 gal. of bleach down into the trap and let it set over night. Next morning flush the mess down with 2 large pans of boiling water, (this is important). The bleach will dissolve the hair and make it slippery and the boiling water will melt the grease and get the mess out of your drain. Smell better now? Cheers TOM

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Originally Posted by Milo Dolezal

We ran into this situation before. It was bacteria growth inside the drain. It had very distinctive odor to it....

Look inside with flash light and see if you have white, slimy looking substance on walls of the drain inlet and pipe - before pipe reaches water in trap. Come back to let me know what you've found out . Thanks. Milo

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Hi... the pipe (PVC it seems) is practically spotless... it's an off-white-ish pipe that was originally filled with black gunk that I needed a screwdriver to break off and long pliers to pull the stuff out! 1 chunk was about 9 inches long and 1 inch thick! Some gunk fell into the drain and there was nothing I could do given the pliers and tools I had... but they should definitely be washed out of the trap... several times I stuffed the open drain with a cloth towel, filled the shower up with about 4-5 gallons of water, and yanked the towel which the water rushed down.

Honestly, I don't see any film... nothing above the water... and the water looks pretty clear (hard to tell with the color of the pipe).

In all this talk about the drain, I gave the drain cover a real good scrubbing with oxi-clean and then Tilex... it wasn't filthy but it had a tad of white slime on it.

I probably can't give you a 100% answer if the smell is gone till tomorrow since I've been around this problem all day and my nose is probably somewhat biased right now.

This problem literally appeared all-of-a-sudden. We took a shower Wednesday morning and were like "what the **** is that smell?!" I'm assuming something that comes this quickly (and snaking the drain provided nothing... and the last time I snaked was about 5 months ago) should be a simple problem to deduce... but maybe a bit tough to solve. :)

My gut tells me the problem is (in no particular order) 1 of the below:

1)Something further down in the drain... because the smell only comes when showering and after a few minutes of showering... maybe the rush of the water and soap allows the gas to come up. But, on the other hand, shouldn't the gas have gone up the vent? I don't know... I really don't know how vents/pipes are set up.

2)I'm just missing something with the cleaning... I've chiseled away the gunk and used pliers to remove (not flush down) as much as possible... the pipe above the water and in the water looks extremely clean... the drain cover was cleaned a few minutes ago extensively. If the problem still persists, I will clean the entire tile/floor/walls but I just did that about a month ago.

3)The vent on the roof is clogged... the vent is right over our shower... in the attic I can see a pipe leading to the vent in the roof. I have no idea how a vent is connected to a shower drain/pipe... do you have a website that has pix or diagrams?

Thanks again for your (and everyone's) help!

-Eric

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Originally Posted by speedball1

Do any of your traps "gurgle" when something's draining? A vent draws air in to reduce suction caused be a discharge. A blocked vent could suction the water right out of the shower trap causing a odor. Unless your lavatory vent runs directly up through the roof it's revented back in the attic and must be cut open to snake.
In the mean time this may be of interest.
Most bad odors in bathroom drains come from rotting hair mixed with grease from the soap. Try this. Remove the two screws holding the strainer. (TIP; put the screws in the soap dish before they get lost down the drain.) Shine a light down there and with a bent coathanger fish out any hair that may be hiding down there. Then pour a 1/2 gal. of bleach down into the trap and let it set over night. Next morning flush the mess down with 2 large pans of boiling water, (this is important). The bleach will dissolve the hair and make it slippery and the boiling water will melt the grease and get the mess outta your drain. Smell better now? Cheers TOM

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1)I don't hear any gurgling... on anything in the house. The shower sounds the same now as it has for the past 2+ years we've lived here.

2)I would never pour bleach down a drain that leads to a septic tank... and every other advice I've read states the same thing. Maybe if it was a city sewer, yes, but not my septic tank/system. I have tried a few scoops of Oxi-clean today.

3)I've already snaked the drain numerous times... even going as far as 20 feet... nothing is pulled back except maybe 4 strands of hair... literally.


Overall it's a bit hard for me to state right now if the problem is going away, is 100% gone, or is the same... I notice the smell the most when I am actually taking a shower... not like the past few hours where I have been cleaning and running water and trying different things... I will give an update tomorrow morning after I've taken a break for awhile. :)


Would this picture be a standard diagram for most bathrooms? Although my shower and sink are on opposite walls, this seems to make sense to me about how a vent works. But, I can't tell you exactly where the vent pipe in my master bath is located compared to this picture... total bummer.


Anyone know of a very long (say 5 feet) wire brush that I could purchase that is flexible and safe for the pipe? The one I got at a local store is only about 11" long (total). If I had a really long scrubby I could douse it with cleaner and scrub further down the pipe... and it would also be thicker than a snake so it might dislodge something the snake isn't grabbing. If you know of such a long item, please give me a weblink and/or proper terminology... I can't find it on plumming sites or Google...

Thanks in advance!

-Eric

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2)I would never pour bleach down a drain that leads to a septic tank... and every other advice I've read states the same thing. Maybe if it was a city sewer, yes, but not my septic tank/system. I have tried a few scoops of Oxi-clean today.

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Perhaps this might be a good time for a few septic tanks facts.
Let me give you a few pointers. Since the septic tank is such an essential part of a sewage system, here are some points to remember about the "care and feeding" of that part of the onsite sewage treatment system.
A "starter" is not needed for bacterial action to begin in a septic tank. Many bacteria are present in the materials deposited into the tank and will thrive under the growth conditions present.
If you feel that an additive is needed, be aware that some may do great harm. Additives that advertise to "eliminate" tank cleaning may cause the sludge layer to fluff up and be washed out into the drainfield, plugging soil pores. Some additives, particularly degreasers, may contain carcinogens (cancer-causing) or suspected carcinogens that will flow into the ground water along with the water from the soil treatment unit.
Send all sewage into the septic tank. Don't run laundry wastes directly into the drainfield, since soap or detergent scum will plug the soil pores, causing failure.
Normal amounts of household detergents, bleaches, drain cleaners, and other household chemicals can be used and won't stop the bacterial action in the septic tank. But don't use excessive amounts of any household chemicals. Do not dump cleaning water for latex paint brushes and cans into the house sewer.
Don't deposit coffee grounds, cooking fats, wet-strength towels, disposable diapers, facial tissues, cigarette butts, and other non-decomposable materials into the house sewer. These materials won't decompose and will fill the septic tank and plug the system. To use a 5-gallon toilet flush to get rid of a cigarette butt is also very wasteful of water. Keep an ash tray in the bathroom, if necessary.
Avoid dumping grease down the drain. It may plug sewer pipes or build up in the septic tank and plug the inlet. Keep a separate container for waste grease and throw it out with the garbage.
If you must use a garbage disposal, you will likely need to remove septic tank solids every year or more often. Ground garbage will likely find its way out of the septic tank and plug up the drainfield. It is better to compost, incinerate, or deposit the materials in the garbage that will be hauled away. As one ad says, "You can pay me now, or pay me later."
Clean your septic tank every 1 to 3 years. How often depends on the size of the tank and how many solids go into it. A rule of thumb is once every 3 years for a 1,000 gallon tank serving a 3-bedroom home with 4 occupants (and with no garbage disposal).
Using too much soap or detergent can cause problems with the septic system. It is difficult to estimate how dirty a load of laundry is, and most people use far more cleaning power than is needed. If there are lots of suds in your laundry tub when the washer discharges, cut back on the amount of detergent for the next similar load. It's generally best not to use inexpensive detergents which may contain excessive amounts of filler or carrier. Some of these fillers are montmorillonite clay, which- is used to seal soils! The best solution may be to use a liquid laundry detergent, since they are less likely to have carriers or fillers that may harm the septic system.
Each septic system has a certain capacity. When this capacity is reached or exceeded, there will likely be problems because the system won't take as much sewage as you want to discharge into it. When the onsite sewage treatment system reaches its daily capacity, be conservative with your use of water. Each gallon of water that flows into the drain must go through the septic tank and into the soil absorption unit. Following are some ways to conserve water that should cause little hardship in anyone's standard of living:
Be sure that there are no leaking faucets or other plumbing fixtures. Routinely check the float valve on all toilets to be sure it isn't sticking and the water isn't running continuously. It doesn't take long for the water from a leaking toilet or a faucet to add up. A cup of water leaking out of a toilet every minute doesn't seem like much but that's 90 gallons a day! So be sure that there is no water flowing into the sewer when all water-using appliances are supposed to be off.
The most effective way to reduce the sewage flow from a house is to reduce the toilet wastes, which usually account for about 40 percent of the sewage flow. Many toilets use 5 to 6 gallons per flush. Some of the so-called low water use toilets are advertised to use only 3.5 gallons per flush. Usually the design of the bowl hasn't been changed, however, and often two flushes are needed to remove all solids. That's 7 gallons! Toilets are available which have been redesigned and will do a good job with one gallon or less per flush. Using a 1-gallon toilet rather than a 5 gallon toilet will reduce sewage flows from a home by about a third. This reduction may be more than enough to make the sewage system function again. While prices may vary, 1.6 gallon toilets can usually be purchased in the $200 range, far less than the cost of a new sewer system. Baths and showers can use lots of water. "Setting up camp" in the shower with a shower head flow of 5 gallons per minute will require 100 gallons in 20 minutes. Shower heads that limit the flow to 1.5 or 2 gallons per minute are available and should be used. Filling the tub not quite so full and limiting the length of showers will result in appreciable water savings.


-Is the water from the faucet cold enough to drink? How long do you let it run to cool down? Keep a container of drinking water in the refrigerator. Then it won't be necessary to run water from your faucets in order to get a cool drink.
There may be other ways to conserve water that you can think of in your home. The main idea is to consider water as a valuable resource and not to waste it.
Following a few simple rules like not using too much water and not depositing materials in the septic tank that bacteria can't decompose should help to make a septic system trouble-free for m, too! Any years. But don't forget the septic tank does need to be cleaned out when too many solids enter the system.
With a water meter you can determine how much water your automatic washer uses per cycle. Many washers now have settings to reduce the amount of water used for small loads. Front loading washers and suds savers use less water than top loading machines. If your sewage treatment system is reaching its maximum capacity, try to spread the washing out during the week to avoid overloading the sewage system on a single day. Septic tanks need tender, loving care too. Good luck, Tom

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Originally Posted by speedball1

Perhaps this might be a good time for a few septic tanks facts.
Let me give you a few pointers.

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Hi Tom... thanks for the tips. I guess everything in life is in moderation but at first glance, pouring 1/2 a gallon of bleach down the drain seemed a bit much. Maybe not. We never use bleach in our washing machine.

On a related note to all your tips... there are only 2 of us in this large 4 bedroom 3.5 bath house... we use the master bath and a downstairs 1/2 bath... the other bathrooms are rarely touched.

-Eric

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there are only 2 of us in this large 4 bedroom 3.5 bath house... we use the master bath and a downstairs 1/2 bath... the other bathrooms are rarely touched.

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Hey Eric,
I hope you use the bathrooms enough so the traps don't evaporate and lose their seal. This would give you a direct connection to the septic tank allowing sewer gas to enter your home. Regards, tom

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Originally Posted by speedball1

Hey Eric,
I hope you use the bathrooms enough so the traps don't evaporate and lose their seal. This would give you a direct connection to the septic tank allowing sewer gas to enter your home. Regards, tom

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Hi... can you elaborate on losing the seal? Do seals rot quickly without water? How quick?

I will make a point to use the other bathrooms' sinks and showers and toilets once a week for 30 seconds each unless you have a better recommendation.

Thanks again.

-Eric

p.s. I am trying the bleach now and will let you know in about 8 hours (6pm EST) how it worked.

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can you elaborate on losing the seal? Do seals rot quickly without water? How quick?
I will make a point to use the other bathrooms' sinks and showers and toilets once a week for 30 seconds each unless you have a better recommendation.

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Trap seals don't "rot", they evaporate . How long it takes will depend on humidity and Your AC.
Just running water in your traps once a week should keep them filled. Good luck, Tom

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Originally Posted by speedball1

Most bad odors in bathroom drains come from rotting hair mixed with grease from the soap. Try this. Remove the two screws holding the strainer. (TIP; put the screws in the soap dish before they get lost down the drain.) Shine a light down there and with a bent coathanger fish out any hair that may be hiding down there. Then pour a 1/2 gal. of bleach down into the trap and let it set over night. Next morning flush the mess down with 2 large pans of boiling water, (this is important). The bleach will dissolve the hair and make it slippery and the boiling water will melt the grease and get the mess outta your drain. Smell better now? Cheers TOM

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Hi Tom... I poured 1/2 a gallon of bleach into the drain (shower had not been used for hours or even the previous night... I forget)... put a towel over the drain and let it sit for about 7 hours... then poured near-boiling water (about 2 gallons) down the drain.

Now to again be clear, there has been NO SMELL all day because nobody took a shower. After pouring the hot water, still no bad smell. I then ran the shower (not me in it) for about 6 minutes at warm temp and adjusting the power of the shower head as if someone were in it... no smell (and this was a similar reaction 2 days ago when I ran the shower without being in it--that there was no stink when I just ran the shower).

To be thorough, I took the hand-wand (which we rarely use) on the shower and sprayed the walls and glass just in case the stink is somehow attached to the walls... and thus only gets stinky when someone is in the shower and the water is bouncing off our body onto the wall... so after spraying for about 2 minutes, no smell. And I looked at all the walls and corners pretty carefully and don't see anything.

The real test will be tomorrow morning (about 14 hours after pouring the hot water) and physically being in the shower using shampoo and bar soap. If the problem exists, it should happen within 4-5 minutes. Again, to be clear, this is a gaseous smell... not an icky smell. This smell is like opening the lid of a septic tank... nothing like the smell of stuff I've ever snaked out of a drain in my life. :)

So this is pretty bizarre.

1)If the smell comes back tomorrow morning when we shower, I will be completely stumped... because why would it only stink when a human is actually in the shower naked and showering? We both use 2 different shampoos so it's not that. We do not stand on the drain but I'm sure the physics of showering is different than just running the showerhead.

2)If the smell goes away, I will state that there was something nasty in the trap (or a bit further down) that I couldn't get/see/snake.


I'm hoping #2 occurs tomorrow morning.

Thanks all!

-Eric

I go on the roof once a year and run a water hose down the vent stacks. Run the hose down as far as it will go and turn the water on full blast for about 3-5 minutes. Learned to do this when my toilet was draining into my tub!

Hey Eric,
Please keep us informed if the smell returns. Good luck and happy showing. Tom

Hi all... ok, so my wife took a shower this morning and this is how it went:

-ran shower for about 2 minutes to get it hot
-she got in and started showering
-7 minutes later the smell started to come... however, it wasn't as much/strong/forceful as the past few days

When she got out, I cleaned the entire shower with Tilex and hot water just to be sure there was nothing on the walls. I also pulled out all the soaps/shampoos in case there was just something in them that was reacting (but they did not smell).

So... about an hour later I took a shower:

-ran shower for a min or so (I like them cooler)
-about 7 minutes later the smell started to come but again, it was not as powerful as the past week.


So the problem still technically exists, but I'm not sure if it is the vent or if it is something in the drain/pipe/trap.

I am going to try another 1/2 gallon of bleach and let it sit for 12+ hours this time instead of the 7+ yesterday. If it still smells tomorrow, then I will have to find someone to go up and check the vent.

-Eric

p.s. why don't they make vents that are open-able from within the attic?. such as having a giant screw that you can unscrew so you can shove a coat hanger up or down. I just don't see the logic in forcing a human to go up on a 30' roof hanging on for dear life to simply shove a hose down it when they could just go to the attic and somehow gain access to the vent pipe say 3 feet below the top of the vent. Heck, forget the screw and just make it so the top 5 feet of the vent pipe screws onto the remaining pipe in the attic.


Alas, the 2nd cleaning of bleach (after 16+ hours of sitting overnight) has not helped. The stink is still here and comes about 7 minutes into a shower. It may not be as overwhelming as a few days ago before I started troubleshooting, but I don't think continuing to pour bleach down the drain is the answer. I may try snaking it one more time but as I've stated earlier, I've snaked it down to 20 feet and nothing was attached to the snake when I pulled it back.

Unless people state otherwise, I think it's time to have someone go up and check the vent. Again, I don't understand why vents are not designed to be accessible in some shape or form in the attic so they can be snaked.

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I think it's time to have someone go up and check the vent. Again, I don't understand why vents are not designed to be accessible in some shape or form in the attic so they can be snaked.

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At the same time have him snake the drain again. I* keep wondering if there isn't something down there sending a bubble of sewer gas back every time you shower.
When the contract calls for cleanouts we do install them on stacks. If you do find out there's a clog in a vent it's a good idea to screen them. Let me know what you find. Good luck. Tom

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Originally Posted by speedball1

At the same time have him snake the drain again. I* keep wondering if there isn't something down there sending a bubble of sewer gas back every time you shower.

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Hi Tom,

Can you elaborate on the snake-the-drain comment? I can snake the drain (that was the first thing I tried and was thinking of doing it again today) to about 20feet and really triple check to make sure nothing is down the pipe. I would imagine it would need to be close by... because if something was lodged 20 feet down, ultimately the gas would go up the vent rather than travel 20 feet up my pipe into the shower. But, I don't have a blueprint of how all the pipes are designed.

I live in CT... I hear it's not wise to install a screen on top of a vent because it can create an ice damn... which would back up the gas.

Can you comment on if I've used too much bleach to harm my septic tank? I would guess I've used about 1+ gallons over the past 2 days... and of course lots of boiling hot water and shower water. Our house is about 4000 sq feet if I remember correctly and has 3.5 baths (but we really only use the master bath).

I was also thinking of filling the shower with water and taking a plunger and seeing if I could force the water through the pipes faster/harder... possibly dislodging anything that is stuck that I (and the snake) does not know about. I'm assuming this is safe as people do it all the time for clogged toilets.

Thanks again for your help.

-Eric

Opps! Forgot about snow and Ice so screening the vents isn't too swift. I haven't seen "snow and ice" for over 55 years so I tend to forget.

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Can you comment on if I've used too much bleach to harm my septic tank?

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A few gallons of bleach isn't going to have much effect in a 1000 gallon septic tank.
This may help.
Shower Drain Odor
By Tim Carter
©1993-2009 Tim Carter
Summary: A shower drain odor can be very unpleasant. The source of the drain odor is often above the water level of the trap. Look at the sides of the drain pipe for biofilm.

Related Articles: Sewer Gas Smell, Foul Odor, Bathroom Sewer Odors, Sewer Gas & Sump Pump, Clog Free Vent Pipes
DEAR TIM: We have a horrible odor coming from the shower drain in our acrylic shower. Five different plumbers have not been able to solve the problem. The first and fourth plumbers said nothing could be done, the second and third plumbers thought the problem was caused by a rocking toilet so they replaced the toilet's wax ring. The fifth plumber said he thought the plumbing drain lines were installed improperly and that the odor was caused each time the toilet flushed. The problem is, the odor just started and all was fine several months ago. I have poured every imaginable cleaning solution into the shower drain and the odor persists. What could be the problem? Shari W. Rancho Palos Verdes, CA
DEAR SHARI: You might be eligible for a place in the record books for having called in that many plumbers for one problem. It is amazing that you have not made any progress on solving the problem. That tells me the source of the odor might not be plumbing related. But to determine this, I am afraid you might have to perform a little exploratory surgery on a wall that is adjacent to the shower.
Odors coming from drains are a common problem in many homes. Some people only have the problem when they run water in a sink or a bathtub. The source of the odor in almost all of these instances is a buildup of biofilm on the sides of the pipes that connect the sink or fixture to the actual P-shaped trap under the fixture. This vertical tailpiece pipe can accumulate a seething bacteria-filled organic layer of slime over time. When water rushes past the slime, it can dislodge some of the molecules into the air and they waft up out of the sink and into your nose.
Biofilm on the drainpipe leaving a shower or any fixture can be a source of odors. Look at the horrible black goo inside the drain! PHOTO BY: Tim Carter To eliminate biofilm as the source of the odor, take the chrome or brass strainer cover off the shower drain so you can see into the drain pipe
. Use soap and water and a larger-diameter bottle brush to thoroughly clean the underside of the strainer, the bowl-shaped drain assembly under the strainer as well as the sides of the vertical drain pipe that extends downward into the p-trap. Rinse thoroughly with clean water until the entire drain is perfectly clean. If the odor still persists, it is time to move on.
Check for mold in the shower and areas near the shower. Active mold growth produces odor. That musty odor you smell when around mold is actually a puff of gas that ejects the mold spore from the mold organism. Imagine if hundreds, thousands or tens of thousands of small mold spores are being ejected each day in your shower. This could easily produce enough gas for you to smell. Remember, this mold could be behind the shower tile or walls and hard to discover. A recent leak that is still invisible could be the source of water that is fueling the mold growth.
A dead animal that somehow found its way into the wall space next to the shower or under the shower assembly could be the source of the odor. This is a remote possibility and the stench of a decaying animal is very distinctive and quite unlike the odor produced by sewer gas or biofilm from a drain assembly.
If this shower shares a common wall with a closet or some other wall surface that can be sacrificed, it is time to cut into the wall(s) to see behind and under the acrylic shower assembly. The first holes can be down low towards the floor so that you can see under the shower pan. Purchase an inexpensive makeup compact mirror and attach it to a stick so you can see around any corners or obstructions under the shower pan. Use a flashlight with the mirror to look up the wall cavities as much as possible to see signs of mold growth.
Odors from drains are voices telling you something is wrong. Think of them as low-powered smoke detectors. This is especially true if the source of the odor is some form of mold. It is not uncommon for a water leak to remain invisible for weeks or months and cause mold to bloom in a hidden location.
Add to this the power of the average human's sense of smell. You would be shocked at how few odor molecules it takes to trigger a response. Natural gas is a great example of this. In its pure state, natural gas is odorless. Gas companies add mercaptan chemicals to the gas so we can smell it if there is a dangerous gas leak. Believe it or not, you can easily smell mercaptans at a concentration level of one-half one part mercaptan to 1,000,000 parts of air!
Investigate the source of all odors. Enlist the help of friends if possible, especially those who might have a better sense of smell. Small holes drilled into walls can be very helpful to help track down the source of an odor. Insert a small clear plastic tube into the hole and determine if the odor is stronger or weaker in that particular location.

Hi Tom,

Can you recommend a few things for me (assuming there is something in the drain/pipe and not the vent):

1)Any particular brand of chemical to try to kill whatever is in the pipe rather than bleach? Maybe some other chemical is more effective and/or more safe for my septic system.

2)A brush that is longer than 11" so I can really shove it down the pipe a bit. I've looked in Home Depot and all they sell are very thin pipe cleaners... I'm looking for something that has a)a very bendable but not breakable long handle... such as metal that is in pipe cleaners and b)has a thick brush as the end... not some tiny little 1/2 inch diameter brush/bristle.


If you have weblinks for the above 2, that would be terrific. I will write back in about an hour after I snake the drain again and let you know if anything comes up.

-Eric


I snaked the drain... used almost all of the 25 foot snake... nothing... absolutely nothing came up... there was a tad of brown water after pulling it all back in but that is normal. Furthermore, I am 99% sure that my shower drain, after a few feet of the trap, goes straight down to the basement... so the piping isn't all across the floor... which I would therefore assume that it would be difficult for stuff to build up on a vertical pipe.

I put the drain cover and the 2 screws in a bowl of bleach for about 8 hours today... it took a bit of the finish off but maybe it cleaned anything else out too.

So tomorrow here is my plan:

1)shower with the drain cover on... if smell persists, it ain't the drain cover. If smell is gone, I will try a few more days/showers and let you know, too.


If smell is still around, I am beginning to wonder if it is truly a vent issue: I went up to the attic and carefully looked at all the piping that is for ventilation. See if you can follow me here:

-the vent leading to the roof is very close to the corner of the house which is the opposite side of the house as the shower.
-the vent leading to the roof is vertically 6 feet tall or higher from the attic floor
-the vent leading to the roof is connected to 2 pipes which make an upside down T... one kind of snakes overhead the kitchen sink and the other side of the T goes about 20 feet horizontally to the shower... along the way attaching to (in this order left to right) the toilet, the hot tub (which we rarely use), then lastly the shower)

So my thinking is... why would only the shower stink? If gas is truly being blocked from leaving the outside vent, it would have to back up a LONG way (6 feet + 20 feet = 26 feet) for it to start to enter the shower. Or, the vent would have to be clogged right above the shower. I don't know... this is driving me nuts. I ran the hot tub (just the water) for about 4-5 minutes today at various pressures and temps and I didn't smell anything.

I think I will have to wait till tomorrow morning and see what else I can report. I will take a photo of my vent piping in the attic and link to it soon for you.

-Eric

No luck... the smell is still here. I'll have the vent cleaned and let you know what happens.

So a few days after my last post on the 4th, I had a plumber come over and look on the 12th. We had not used the shower since the 7th so I was expecting it to stink like mad when we fired up the shower.

Nope... the shower ran fine with no stink... I was in showering for over 10 minutes. Now, to be fair, we had just cleaned the shower top to bottom the day before.

He went up in the attic and cut the vent pipe... no smell and he snaked the vent each way... nothing was clogged. We ran hot and cold water down the vent pipe for about 10 minutes... no problems. We ran water in the shower and vents for probably a total of 30 minutes which definitely should have reproduced the problem if there was a dead animal in the wall or something like that. We tried all sorts of things for 1.5 hours and could never reproduce even a hint of the smell.

Now, Nov 18, the shower is beginning to stink again!!

I'm at a loss... there's no way 2 people showering once a day each could possibly leave/create that much biofilm on the shower itself or down the drain. Also, it's next to impossible to find out the source of the smell. If there was a dead animal in the wall, then why did it not smell the past 6+ days? If a pipe was broken somewhere or a vent was clogged, why would the smell not be here for the past 6+ days?

Any other suggestions?

Eric,
There is many things that can cause odors to emit from drains. The #1 cause that I have noticed is from soap scum, and the bio-film which lives in this organic matter.

You can snake and use bleach as well as other harmful chemicals to get rid of this problem for a little wile, or you can use natural enzymes and microbial cleaners that will actually continue to feed on this muck that forms in the drains.

I myself prefer to use non toxic earth friendly products.

Sani-Drain makes a wonderful product that suspends from the drain cover or sits in your sink
That slowly leaches out enzymes and microbes that feed on this complex organic matter which in turn dissolves it into water and carbon dioxide. These microbes actually breed in your drain lines doubling every 15 minutes as long as there is muck in your drain to feed on.

A lot of Plumbers don't like this type of product because it eliminates service calls and can reduce waste management by 50%.

Here is the website Sani-Drain, Visually effective Microbial drain deodorizer