So, I hope I can explain what I know. I will hire a plumber to come look, but wanted to see if I could get any advice first, as I am a pretty good DIY. I've redone our house from galv. to pex for supply, and replaced the non-inslab portions of the rusting waste lines that were galv./iron, so I have a handle on the basics, but this is beyond me.
- House built 1951, Septic Tank installed then, 2 90ftx3ft seepage trenches installed in back yard (I have the permit and drawing).
- House hooked up to city sewer in 1966, 4 inch CIP.
- Upstairs bathroom; toilet and shower/tub go straight into the 4 inch main stack which is exposed in the basement.
- Downstairs bathroom; toilet and shower go straight down into pipe in slab. Kitchen sinks tie into this line too, without issue - 2 vents. This line appears to go along the back wall of the house, under the slab, in direct line with the main stack. The downstairs toilet is about 8 ft to the right of the main stack.
A few years ago we started to note a bit of a sewer smell in the downstairs bathroom when it rains. It goes away in the dry months. Finally I started to try to troubleshoot it, and hooked up smoke to a drain line, thinking it was a rusted through vent somewhere (I've pulled off the walls around most of the joints of the vents already...sigh).
Alas, smoke came out of the slab where it meets the wall (this is in the basement bath, behind the toilet). Ok, so I thought maybe there is a crack in the sewer line under the foundation. I borrowed a sewer scope camera.
What I found is, if right, I think very unfortunate.
The upstairs bathroom and shower go right into the main vertical stack, which is exposed in the basement. When I put the scope in the cleanout at the base of this stack, after a twist and a turn, I find myself in what must be the sewer line to the street, because it goes for 50 ft. There's not 50 ft of plumbing in our house, much less in a straight line. It looks fine.
When I put the scope into a cleanout in the downstairs bathroom, there's an obvious opening for the toilet, all the other house sinks, a vent, and then it goes into a 4 inch line going horizontally that ends in...what looks like a septic tank, full to the top. It goes about 16 feet, then there's a bend, then there's a lot of water with stuff floating in it, which I assume is the top of the old septic tank which supposedly was decommissioned in 1966.
My question: how is this possible. There appears to not be any sort of connection between the two lines.
All the plumbing in the house, I believe, has not changed - the downstairs wasn't added, etc, there were always 2 bath. In any event, even if they had added the downstairs bath later, why hook it up to the septic, and not the sewer? How is it possible for a septic tank, even with really really well working leech lines to not be pumped for 50 years (we've owned the house for 11) even with light use? (I think the upstairs bath, which is hooked to the sewer, has always gotten most of the action.) We have never ever had any sort of backup anywhere in the house.
My theory on the smell is that in wet weather, the leech lines aren't keeping up and there's some sewage coming into that line and sitting, and that's what we're smelling, through seams in the pipe. It flows back out to the tank when things dry out a little.
I realize this is a complex post and a drawing would probably simplify, I may try to work one up. What should I be asking, what should I be doing to try to fix this situation?
To summarize: I *think* but am not certain:
- We have an upstairs bath where the toilet and shower are hooked up to the sewer (the laundry is too)
- We have a downstairs bath where the toilet, shower and every other sink in the house is hooked into a septic tank
- there are permits and drawings on file that the house was hooked up to city sewer 50 years ago and the septic was disconnected.
ANY help is appreciated and sorry for the novel!
- House built 1951, Septic Tank installed then, 2 90ftx3ft seepage trenches installed in back yard (I have the permit and drawing).
- House hooked up to city sewer in 1966, 4 inch CIP.
- Upstairs bathroom; toilet and shower/tub go straight into the 4 inch main stack which is exposed in the basement.
- Downstairs bathroom; toilet and shower go straight down into pipe in slab. Kitchen sinks tie into this line too, without issue - 2 vents. This line appears to go along the back wall of the house, under the slab, in direct line with the main stack. The downstairs toilet is about 8 ft to the right of the main stack.
A few years ago we started to note a bit of a sewer smell in the downstairs bathroom when it rains. It goes away in the dry months. Finally I started to try to troubleshoot it, and hooked up smoke to a drain line, thinking it was a rusted through vent somewhere (I've pulled off the walls around most of the joints of the vents already...sigh).
Alas, smoke came out of the slab where it meets the wall (this is in the basement bath, behind the toilet). Ok, so I thought maybe there is a crack in the sewer line under the foundation. I borrowed a sewer scope camera.
What I found is, if right, I think very unfortunate.
The upstairs bathroom and shower go right into the main vertical stack, which is exposed in the basement. When I put the scope in the cleanout at the base of this stack, after a twist and a turn, I find myself in what must be the sewer line to the street, because it goes for 50 ft. There's not 50 ft of plumbing in our house, much less in a straight line. It looks fine.
When I put the scope into a cleanout in the downstairs bathroom, there's an obvious opening for the toilet, all the other house sinks, a vent, and then it goes into a 4 inch line going horizontally that ends in...what looks like a septic tank, full to the top. It goes about 16 feet, then there's a bend, then there's a lot of water with stuff floating in it, which I assume is the top of the old septic tank which supposedly was decommissioned in 1966.
My question: how is this possible. There appears to not be any sort of connection between the two lines.
All the plumbing in the house, I believe, has not changed - the downstairs wasn't added, etc, there were always 2 bath. In any event, even if they had added the downstairs bath later, why hook it up to the septic, and not the sewer? How is it possible for a septic tank, even with really really well working leech lines to not be pumped for 50 years (we've owned the house for 11) even with light use? (I think the upstairs bath, which is hooked to the sewer, has always gotten most of the action.) We have never ever had any sort of backup anywhere in the house.
My theory on the smell is that in wet weather, the leech lines aren't keeping up and there's some sewage coming into that line and sitting, and that's what we're smelling, through seams in the pipe. It flows back out to the tank when things dry out a little.
I realize this is a complex post and a drawing would probably simplify, I may try to work one up. What should I be asking, what should I be doing to try to fix this situation?
To summarize: I *think* but am not certain:
- We have an upstairs bath where the toilet and shower are hooked up to the sewer (the laundry is too)
- We have a downstairs bath where the toilet, shower and every other sink in the house is hooked into a septic tank
- there are permits and drawings on file that the house was hooked up to city sewer 50 years ago and the septic was disconnected.
ANY help is appreciated and sorry for the novel!
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