septic stink in basement - help!

[hazmat]

We are getting a septic smell in the basement. Smell is more noticeable after a shower. No leaks can be found. On advice of my plumber, I had the septic tank pumped.

I imagine if it were a plugged vent, that I'd be having draining problems in the rest of the house.

Thoughts?

 

[jinman]

Every major drain in my house has its own vent. You could have one vent plugged to the shower and that could be causing it to produce the pressure leading to gas in the basement. Do you have any idea where the gas is escaping in the basement? Do you have a sink or commode that is bubbling back through the trap?

If none of the traps in the basement are dry (including air conditioning condensate drains), then you might have a stress fracture in the sewer drain that is letting gas escape. Not knowing the age of your house nor the type of system reduces me to just guessing though.

Maybe I'm missing something, but I don't understand how sludge in a septic tank could cause backpressure or leaks if your normal vents work and the drains work normally. I guess I'm saying that old sewage doesn't smell any worse or produce anymore gas than new sewage in my estimation. I'm not sure how an empty tank would solve your problem, and I'll be surprised if it does.

 

[hazmat]

House is 15 years old. Waste plumbing is PVC. There is only one trap in the basement (laundry). We average 3 loads a week, so I'm pretty sure it is not dry.

Septic sytem is basic - waste from house leads to 1,500 gallon tank & then out to leach field.

How does one find a stress crack in PVC?

The smell is there all the time & is exacerbated by additional flow (from any thing - shower, laundry, toilet). My trained nose says it smells of "septic gas" - not as ripe as the "new additions" down the drain. I'm not calibrate well enough to determine between old septic & new septic

 

[dbdartman]

Sounds like a vent problem to me. First thing I'd suggest is get up on the roof & run a snake down through ALL the vent pipes. If the right vent pipe is clogged/stopped up, it may cause a vacuum on the main line & could be pulling the water from the trap at the laundry.

 

[Tig]

Some septic guys around here reccomend a vent at the tank. That won't fix your problem, but it may help. I wonder if septic pros have methane sniffers. That would help track it down.
Fill your laundry tub with water, flush. If the smell appears it's not the laundry trap.
How long has this smell been around?

 

[ToadHill]

Check the inlet to the tank. I had gas problems several years ago and found the entry point mostly blocked with soap scum. This caused the liquid to drain slowly into the tank and leave waste in the pipe to the tank. This then caused the smell, as soon as I cleaned the soap scum the problem went away.

 

[WayneB]

Wonder how long has it been since you had the tank pumped? If it has been a long time have it pumped and ask them to check the inlet pipe. around here they will do it for you as part of the pumping charge.

 

[MikePA]

Wonder how long has it been since you had the tank pumped?

On advice of my plumber, I had the septic tank pumped.

.....

 

[Richard]

When we moved in our house, we had similar problem. Later, discovered that there was a vent pipe that was never completed . It was actually venting into the laundry room

I don't know how anyone missed it but they did (including me).

I have since then routed some pipes to at least, dump it back into the same system. Smell is gone and washer drains fine (as does the mega shower that I just installed with 3/4" pipes AND mixer valve...meaning it's 3/4" throughput)

 

[PA hayseed]

I would agree with most that it is a venting problem. Other possible sources I would check are for a floor drain that might be covered or sealed up, and if you have a sump pit or a floating basement I would check those areas as well. Don't automatically rule out all possibilities.

Good luck.