[Zamoeba]

Whichever one of you esteemed plumbing masters can answer this riddle, shall win my respect and adoration:

We moved into this circa 1953 construction house in suburban Chicago. The home inspector had no clue as to the purpose of this inconvienently-located green pipe in our basement. It is plugged at the top with some sort of foam or stuffing. The white pipe to the left is one of the sumps. The "sump" is a rectangular hole cut through the foundation. There is gravel underneath. The basement looks to have had aftermarket drain tile installed, as all along the perimeter of the basement, at the joint between the floor slab and the walls, is what looks to be a hydraulic cement fill of some type. And on the other side of the basement is a newer sump plus sump pump, and I can see drain tile pipe at the bottom of the sump.



The pipe is painted the same green color that the original sewer stack is painted. We have an old-style, non-overhead sewer, on the other side of the basement, where the lateral runs from the front of our house to the main under the street.

I strongly think that the sump outlet is wired directly into a storm sewer, which most likely runs along the length of our driveway.

Do you have any idea what is the purpose of this green pipe, and can I remove it?

Thanks in advance,
Paul

[ballengerb1]

It is probably an old vent stack but can you follow it as it goes into your first floor level? If it is a vent it should eventually go out through the roof. I suspect that your sump is not going into the sewer since it appears to exit between the floor joists. What do you see outside the foundation wall? The sump PVC should come through the foundation.

Please rate my answer so I'll Know if I helped you. Good luck

[Zamoeba]

It is probably an old vent stack but can you follow it as it goes into your first floor level??

Although it's a bit difficult to see in this picture, the pipe ends here in the basement. The top of the pipe is threaded. The white PVC is a sump line, that goes out through the sillplate into the crawl space past that window, where it then goes into a cast iron pipe that goes out through the side of the house, and then runs underneath the driveway and then to God knows where... when that sump runs, I can hear the water splashing somewhere under the driveway... where I suspect a storm sewer is running.

I really want to believe that at some point, the green pipe led where the white PVC pipe now leads, but it doesn't make much sense that the green pipe just runs straight down into the concrete.

If you look closely, you can see ripples in the concrete around the green pipe where it looks like the pipe was added after the original floor cured... it's a complete mystery to me, and I'd love to cut it off right at the floor and fill it with concrete!

Also, our vent stack is over on the other side of the house, where the main sewer stack is. It's a big honker of cast iron pipe that goes up through the attic and to the roof.

Thanks,
Paul

[ballengerb1]

It is hard to tell but it does not look like the green pipe stops at the flooring material. It looks like it goes through the floor into your first floor. It does not appear to be a load bearing support

[labman]

The bulge towards the top looks like a pipe union. You can unscrew the center nut and remove the top part. That will require a large wrench and perhaps a sturdy guy. Once apart, you can shine a light down it and maybe get a clue. If sewer gas comes flowing out, you will quickly want to stop it up again. There could have been many remodeling since 1953. Is there any other signs that here may have once been a bathroom above it?

I vote to remove it unless something turns up when you open it. While you have the sturdy guy and big wrench, you might bang around the bottom of it good with hammer and then try to unscrew it. It it screws out, you could replace it with a plug.

[Zamoeba]

The bulge towards the top looks like a pipe union. You can unscrew the center nut and remove the top part. That will require a large wrench and perhaps a sturdy guy. Once apart, you can shine a light down it and maybe get a clue. If sewer gas comes flowing out, you will quickly want to stop it up again.

Good idea! Yes, that's a pipe union. I will try to unscrew it and see what's going on. After looking more closely at the top of the pipe, there appear to be very old cigarette butts in the top of the pipe! I haven't dug them all out to see what's underneath, but this pipe has been dry and plugged for a long time, apparently. Weird!!

So, unscrew it I will and see what's happening. Could it be a standpipe for groundwater?

There could have been many remodeling since 1953. Is there any other signs that here may have once been a bathroom above it?

No chance of that. However, it is directly under the kitchen, which is in its original layout, and the flooring plywood is original material, and there is no sign at all that the pipe went straight up through the floor at any point in the past. Also, there's another sewer pipe against the exterior concrete wall out of the right side of this picture frame.

I vote to remove it unless something turns up when you open it. While you have the sturdy guy and big wrench, you might bang around the bottom of it good with hammer and then try to unscrew it. It it screws out, you could replace it with a plug.

I'll try to uncouple it at the union first, and take it from there. Thanks!

[Zamoeba]

It is hard to tell but it does not look like the green pipe stops at the flooring material. It looks like it goes through the floor into your first floor. It does not appear to be a load bearing support

The green pipe stops 6-10 inches short of the ceiling in the basement. The white PVC goes even higher before making a 90 degree turn towards the back wall. I can almost wedge my whole head in the gap to look into the top end of the pipe. The plywood is original and there is no chance this pipe ever went up there.

[iamgrowler]

From the condition of the floor in the picture you posted and the presence of a ground-joint union on the stack, I'd say it was once a part of a sewage ejection system.

The original sump pit was likely abandoned for one reason or another and the durham 90 that was originally at the top of the stack and discharging into a main stack was also abandoned for one reason or another.

[Zamoeba]

From the condition of the floor in the picture you posted and the presence of a ground-joint union on the stack, I'd say it was once a part of a sewage ejection system.

The original sump pit was likely abandoned for one reason or another and the durham 90 that was originally at the top of the stack and discharging into a main stack was also abandoned for one reason or another.

Very interesting! Well, it's going to take me a few days to get a big enough pipe wrench and take the top section off to see what's down there... if this was an ejection pipe, where in the heck was it being ejected? The main stack is clear on the other side of the basement... I should sketch out a diagram... it may help provide a clue to my riddle.

As you can imagine, I'd really like to get the darn thing out of there, since it is a pain to maneuver around...

Thanks a lot for your guess...

-paul

[doug238]

It could have been a vent for a previous ejector system or a pipe for future use or a vent for the existing ejecter. An ejecter needs a vent. I don't see one on your system.

[ballengerb1]

One last thought and I think someone mentioned this possibility. It might have been a floor drain at one time and someone added a stand pipe to stop water flooding/seeping into the basement. A friend removed his stand pipe and plugged it. Next Spring during a huge storm her heard a big noise in the basement. Hydrolic pressure from the ground water buckled up his basement floor. My vote, remove it but don't plug it until you are sure there is no ground water pressure.