Intermittent septic smell in bathroom
#1
04-27-13, 11:51 PM
Join Date: Apr 2013
Location: USA
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Intermittent septic smell in bathroom
Hi
We are experiencing intermittent septic smells in our bathroom. We have a conventional septic system with a 500 gallon tank. It was pumped and inspected in early February of this year. The problems began in mid March and in the six years we have lived here we never experienced this issue before.
Our home is a funky small cabin, approximately 800 square feet. Besides the full bath there is a washing machine and a kitchen sink/dishwasher. There is only one vent, located just outside the restroom.
The problem seems to occur most frequently following heavier water use, such as doing a load of laundry and dishes within the same day. I was able to disassemble part of the vertical portion of the vent (it runs on the exterior wall) and found nothing blocking it. I ran a 20' snake down the vent from this location (passing toilet, bath, and bathroom sink drains) and did not encounter any resistance. I tried running water down the vent for five minutes. It drained normally.
Ive asked friends and searched online for ideas, but I am at a loss as to what could be causing this problem and welcome suggestions!
We are experiencing intermittent septic smells in our bathroom. We have a conventional septic system with a 500 gallon tank. It was pumped and inspected in early February of this year. The problems began in mid March and in the six years we have lived here we never experienced this issue before.
Our home is a funky small cabin, approximately 800 square feet. Besides the full bath there is a washing machine and a kitchen sink/dishwasher. There is only one vent, located just outside the restroom.
The problem seems to occur most frequently following heavier water use, such as doing a load of laundry and dishes within the same day. I was able to disassemble part of the vertical portion of the vent (it runs on the exterior wall) and found nothing blocking it. I ran a 20' snake down the vent from this location (passing toilet, bath, and bathroom sink drains) and did not encounter any resistance. I tried running water down the vent for five minutes. It drained normally.
Ive asked friends and searched online for ideas, but I am at a loss as to what could be causing this problem and welcome suggestions!
#2
04-28-13, 02:51 AM
Welcome to the forums! Aside from any interior ptraps being dry, which can allow odors in, the location and height of your vent stack could allow odors to settle around the house. Is it just inside the bathroom, or do you smell it while outside as well?
#3
04-28-13, 09:41 AM
"Aside from any interior ptraps being dry, which can allow odors in,"
Let me translate this for you and give you an example. In my house, we have a shower in a second bathroom that never gets used. Because it never gets used, the water in the trap dries up and this allows sewer gases to come in through the drain. So once a month or so, I pour a glass of water in the drain. In fact, your post reminded me, so I went and did it just now.
All the drains can be hooked to the same drain pipe and use the same vent, but all the traps must be kept wet. If you go away for a month or two, chances are things are drying out.
Any drain is like this, whether it is shower, kitchen or bathroom. So think about that for a while.
The vent pipe has to be high enough for the wind to carry away the smells. It's like a chimney. Some people live where there is no wind. Then the vapors are not carried away, but settle to the ground.
Let me translate this for you and give you an example. In my house, we have a shower in a second bathroom that never gets used. Because it never gets used, the water in the trap dries up and this allows sewer gases to come in through the drain. So once a month or so, I pour a glass of water in the drain. In fact, your post reminded me, so I went and did it just now.
All the drains can be hooked to the same drain pipe and use the same vent, but all the traps must be kept wet. If you go away for a month or two, chances are things are drying out.
Any drain is like this, whether it is shower, kitchen or bathroom. So think about that for a while.
The vent pipe has to be high enough for the wind to carry away the smells. It's like a chimney. Some people live where there is no wind. Then the vapors are not carried away, but settle to the ground.
#4
04-28-13, 05:03 PM
Join Date: Apr 2013
Location: USA
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Thanks for the replies!
The odors are definitely inside the house and restricted to the bathroom. Since it is a small house all of the assorted drains are used on a regular, almost daily basis. Lack of water in the p-traps shouldn't be the issue.
We are in a bit of a hollow and on rare occasions (once or twice per year) the septic odor will be slightly noticeable outside. The odors we are getting inside are comparatively off the charts.
Is it possible that the wax seal on the toilet could be letting gas through but not leaking fluid?
The house is sort of post-on-pier construction, but the bathroom area is only about 8" off the ground so it is hard to see clearly. Could odors make their way up into the house if a rodent had chewed through a drain pipe? This wouldn't explain very well why it is intermittent and usually associated with higher water usage.
Could another possibility be that the septic tank outlet is restricted and we are getting back up of material that blocks the vent but hasn't made it into the bathtub (lowest drain)?
The odors are definitely inside the house and restricted to the bathroom. Since it is a small house all of the assorted drains are used on a regular, almost daily basis. Lack of water in the p-traps shouldn't be the issue.
We are in a bit of a hollow and on rare occasions (once or twice per year) the septic odor will be slightly noticeable outside. The odors we are getting inside are comparatively off the charts.
Is it possible that the wax seal on the toilet could be letting gas through but not leaking fluid?
The house is sort of post-on-pier construction, but the bathroom area is only about 8" off the ground so it is hard to see clearly. Could odors make their way up into the house if a rodent had chewed through a drain pipe? This wouldn't explain very well why it is intermittent and usually associated with higher water usage.
Could another possibility be that the septic tank outlet is restricted and we are getting back up of material that blocks the vent but hasn't made it into the bathtub (lowest drain)?
#5
04-28-13, 05:58 PM
It is a very good possibility the wax ring can fail and not let water out, but let gasses out. In addition, you may want to clean the traps of the shower/tub and sinks with one of those reverse barbed rods available at box stores. You will be amazed at the rotted hair and stuff you will pull up out of them. THIS alone can cause a similar smell. BrassCraft Zip-It Bath and Sink Hair Snare-BC00400 at The Home Depot
