Septic Smells

[the old grind]

What I've always been told, .. pumping can cause as much trouble as it fixes. Also, I am fully aware that by the time you notice a problem, it's probably time to replace the drain field.

Could the field be slow enough to push out some gas (below all traps btw) during high use but not slow enough to back up into a shower/tub or floor drain. Glad that hasn't happened yet, but ...

btw, right away I'd divert the washer water (gray vs sewage) out of the system.

 

[paulsharvey]

I'm wondering if the system gets so little load that it doesn't get full enough to get to the drain field/effluent discharge, whatever he has. Even still, the easy best gets is the lid isn't sealed but it could be several different things. The fact that the smell is outside points me to tank/lid/effluent lines, or a crack in a pipe from the house to the tank.

 

[CADplans]

I'm wondering if the system gets so little load that it doesn't get full enough to get to the drain field/effluent discharge,

Back when I built my shed, I had a few extra $$$,, so I put a 1,000 gallon septic tank in the ground. It is a concrete tank.

The hope was that if I run rain water into it long enough,, the debris in the gutter water (leaves, seeds,, etc) would seal the tank enough to hold water,,

Basically ,, it would be a cistern, i could water the garden,

Well,, the roof feeding the tank with water is about 2,000 square feet,,
The septic tank gets PLENTY of water,,

I installed the tank in 1999,,
that is what?? 25 years?? the tank has NEVER been full.
A few minor cracks,, ALL the water escapes.

Possibly the best thing the OP could do is run a gutter into the septic tank.
Get the effluent moving through the tank, so that it works like normal.

 

[grsthegreat]

My concrete septic tank was 1000 gal piece o cra*. It continually leaked at the mid seal. Had it ripped out of the ground 5 years ago and installed a 1000 gal poly tank. No leaks. Much better.

 

[paulsharvey]

Anyone who has worked on a sanitary sewer utility will be familiar with the fights against InI. Infiltration and Inflow. It's kinda the exact opposite issue; it's ground water getting into the sewer, and needing treated, which is expensive. Common causes are manhole lids (inflow), water just running in at the pick hole, if the MH lid is in a low area, the annular space at pipe penetrations; we now use rubber boots, but in the older days, it was brick and mortar. Cracked pipes, brick manhole structures, ect, all allow ground water to enter the system. So, now almost all utilities have the MH coated in bituminous coating, and in some cases, epoxy lined, or fiber glass welded liners, slip lining pipes, even foams that are injected through the walls to keep water from getting in. Clean ground water getting in is the issue, not so much some 99% water, with some 1% solids getting out, isn't really the issue.

Point being, concrete leaks.

 

[airbiscuit]

Off topic, but the heading reminds me of the kid describing his dad. "My old man can't see, and he can't hear, but he still smells."

 

[shock]

So, just a follow up since I received lots of advice from those trying to help.

I took the lid off the septic tank, didn't smell all that bad actually. I wonder if the baking soda I put down there 2 weeks ago to balance the ph helped? Regardless, smell wasn't bad.

Before I took the lid off however, I did the smoke test, while I could smell the smoke bomb (had a distinctive smell when burning), I could not see any smoke coming from the lid or cleanout, just a smell nearby those locations.

So, took the lid off. No oil buildup on top. We're very careful not to dispose of oil into the drains. And then I took a wooden probe to test how deep the sludge was........nothing. Couldn't feel any sludge at the bottom, and no solids came up in the probe. Don't know if this is good or bad, but I assume the tank didn't need pumped in any case I take it, since no sludge.

I did notice a that the water (effluent?) level of the tank was about 6" below the inlet, and about 4" below the outlet pipe. I don't know if this is how they work, we hadn't been to the cabin in 2 weeks prior.

I put a gasket on the underside of the lid and replaced it.

So, we'll see if the gasket helps.....

 

[gstrom99]

I did notice a that the water (effluent?) level of the tank was about 6" below the inlet, and about 4" below the outlet pipe. I don't know if this is how they work, we hadn't been to the cabin in 2 weeks prior.

If the "water" level in the tank is below the outlet, sounds like the tank is leaking. The smell may well be coming up from the surrounding ground.

 

[shock]

If the "water" level in the tank is below the outlet, sounds like the tank is leaking. The smell may well be coming up from the surrounding ground.

That's what I didn't know, if the outlet had a leak. I couldn't see the outlet hole itself as it was a vertical pipe and that's all I could see.. I assumed there was then a 90 to go to the outlet.I have a hard time believing the tank has a crack or leak itself since they are pretty stout and there's no traffic around it. It possible, but improbable imo. I did gran the outlet pipe and try to wiggle it, to see if it was loose, but was on there pretty good.

I'll see if the smell returns. If it does, I'll dig down to the outlet pipe and see if anything is leaking around that.

I also thought about filling the tank up to the outlet pipe and then wait a day or 2 to see if it leaks down below it.

 

[ponytug]

So, just a follow up since I received lots of advice from those trying to help.

I took the lid off the septic tank, didn't smell all that bad actually. I wonder if the baking soda I put down there 2 weeks ago to balance the ph helped? Regardless, smell wasn't bad.

Before I took the lid off however, I did the smoke test, while I could smell the smoke bomb (had a distinctive smell when burning), I could not see any smoke coming from the lid or cleanout, just a smell nearby those locations.

So, took the lid off. No oil buildup on top. We're very careful not to dispose of oil into the drains. And then I took a wooden probe to test how deep the sludge was........nothing. Couldn't feel any sludge at the bottom, and no solids came up in the probe. Don't know if this is good or bad, but I assume the tank didn't need pumped in any case I take it, since no sludge.

I did notice a that the water (effluent?) level of the tank was about 6" below the inlet, and about 4" below the outlet pipe. I don't know if this is how they work, we hadn't been to the cabin in 2 weeks prior.

I put a gasket on the underside of the lid and replaced it.

So, we'll see if the gasket helps.....

Both the inlet and the outlet should be covered, and the only way they wouldn't be is if the tank has a leak.

So, congratulations on finding the problem, but as the level is below the inlet and outlet you are most likely looking at pumping the tank out, digging the tank up, and probably replacing it.

If you don't have one already, I would recommend adding an exit effluent filter on the tank to minimize any solids moving out of the tank into whatever your drainage is.

All the best,

Peter

 

[bigtiller]

My septic sucking service guy said an unused tank (think snowbirds) could freeze in the winter. Any chance of that?

 

[ponytug]

My septic sucking service guy said an unused tank (think snowbirds) could freeze in the winter. Any chance of that?

Depends on where the frost line is in any given year, but it is certainly possible, especially if it was installed without any foam insulation on top of the tank and excavation, which is uncommon in the US, though more common elsewhere.

I've seen a nominal 4 foot frost line become 10 feet down in a really dry, cold winter, and boy did that freeze a lot of pipes.

All the best,

Peter

 

[shock]

My septic sucking service guy said an unused tank (think snowbirds) could freeze in the winter. Any chance of that?

That's possible I guess, we've had a few winters of -15 for multiple days in a row since installed

 

[grsthegreat]

Is this a concrete 2 piece tank or a plastic tank.

My concrete tank leaked at the seal. Took many years, by finally could smell it. Years ago we ripped it out of the ground and replaced it with a plastic tank. The plastic tank has about 70-80 locking tabs on it. It will NEVER leak.

 

[paulsharvey]

So, I would NOT jump to having tank replaced on a camp.

I thought our OP had a poly tank? If he had a concrete; I would carefully dig around tank, and if the lid-tank is leaking, I would mix up some mortar, and mud up the outside lid-tank.

 

[shock]

Correct, poly tank.

 

[RSKY]

We had a similar problem except inside the house and only in the utility room where the washer is located. We had the washer put on a separate line to a gravel field when we had two teenaged daughters living at home. So I thought the smell was coming from one of the two drain pipes behind the washer. Swapped lines back and forth ever time we washed a load. Checked this and that and finally called a plumber. He crawled around under the house for an hour or so and found nothing. Then he followed the line back into the house and finally decide it was some kind of valve that vented the line going to the gravel bed. Said he had never had one go bad before but he would go and get one on bring it back. Now this problem had been going on for a couple months or so and shortly after the plumber left my wife opened the chest freezer that was next to the washing machine and the smell hit her. She got to looking around and behind the freezer, in front of the only heating/air conditioning vent in the room, was a bag of onions that had been hanging on the wall. They had fell down behind the freezer, in front of the vent, and were very rotten. The smell only spread into the room when the hear or air came on.

I called the plumber and explained that we had found the problem and to send me a bill for his time. Last I heard was him laughing and he never sent a bill.

Whole point of this sad story is that you need to look around and make sure it is the septic system causing the smells and not something else. We only smelled the rotten produce when the air or heat kicked on. All other times we smelled nothing. Notice what else is going on around the cabin when you detect the unpleasant aroma.


RSKY

 

[dougtrr2]

That reminds me of tracking down a smell in my garage. I was sure there was a dead squirrel somewhere. Only got whiffs of smell every now and then.

Smell turned out to be from my wife's minivan. We had picked up our share of a butchered cow. One small steak had fallen out and was underneath the rear seat. My wife does't have the best sense of smell, and once the van started moving the smell was sucked out the back so you didn't smell it while driving.

Doug in SW IA

 

[paulsharvey]

So, to our OPs issue specifically, given his details;

if we can say the tank access lid is the source, I'd run a bead of polybutylen (probably spelled wrong) or a roofing tar at the lid to seal it; yes, both can be removed for future maintenance work, but both bond well on the PVC of the tank

if we can eliminate the lid/tank junction; I'd throw some lime around the effluent lines. Still not 100% sure what the grey water treatment method is, but lime will largely kill the smell, whether lagoon, spray field, soggy drain field. It's a temp solution, and doesn't treat the cause.

If this is a convention (in my part of the world) gravity to tank, gravity to junction box, gravity to a E shaped drain field systwm; I would search for soggy areas, that would lead me to a crushed, separated, or damaged line. I would then dig that area up with a shovel, confirm and repair with a 4" fernco.

If we can't track it down to the lid or effluent areas; I would go back towards the home. I assumed slab on grade, but if stem wall, or pier foundation, I would (as much as I hate it) crawl under there, and inspection the DWV pipes for seperation/cracks/leaks/rodent damage.

Edit: also, noone had mentioned, there should be (not always) a 4" screw in PVC clean out somewhere outside the home, but very close, maybe within a couple feet. It could be a missing cap, a leaking cap, loose cap, or cracked. It could be Under the porch, if the porch was installed after the DWV lines.

 

[gstrom99]

That reminds me of tracking down a smell in my garage.

When I worked at a large Buick dealership (late 70's), someone traded in a car and left a full milk carton (the waxy paper kind) in the trunk. It was in there for quite a while (hot summer months) and leaked all over. BOY DID THAT STINK. We never got the smell out of it and had to wholesale the car.