Not much experience with plumbing systems, but I'll try to be as clear as I can. Our basement is not finished, but is roughed in for a full bath. There is a plumbing vent coming down from the first floor into the basement area - it extends straight down about 8 inches and is capped off. I assume this is where we could connect the venting if/when we put in a basement bathroom.

I believe this capped-off vent pipe has collected a significant amount of water (it obviously has nowhere to go because the pipe comes straight down and is capped). When we get significant amounts of rain or snow, we're getting a leak coming down the outside of the vent pipe onto the basement floor. We've eliminated the possibility of a roof leak, so I'm GUESSING there is some kind of crack or joint leak in the 1st floor bathroom directly over the basement leak. My theory is that the water is accumulating in the capped vent pipe and when the water rises to the level of the problem area (i.e. the crack or bad joint), it leaks. We ONLY have this problem during times of heavy rain/snow, and then it goes away. Again, I'm guessing because the water level in the capped vent pipe drops below the problem area and it only happens again when the water rises with the next rain.

I'm planning to get inside the wall to identify and repair the leak. In the meantime, I'd like to know if I could remove the cap from the vent pipe in the basement and connect the vent pipe to my septic drain about 4 or 5 feet away? There is already a capped connector at the septic drain pipe for use when a basement bathroom is installed. Again, my theory is that this will prevent water from accumulating and it will instead just run into the septic system. I do not, however, want to cause any problems with proper venting of my plumbing system. Sorry if this isn't clear enough. I'm happy to answer any questions AND I sincerely appreciate any advice.

Good thinking. Yes, you can connect to your existing septic drain.

I think you refer to your 'sewer ejector" as "septic" . Correct ?

THANKS for the quick answer. There is a second sump hole just for a sewage ejector, but nothing is currently installed in that hole (because no bathroom yet). There is a capped connector in the main septic drain line that the sewage ejector would eventually be connected to (again, when we put in a bathroom). For now, I was thinking of just connecting the vent pipe directly into the septic line. I HOPE that makes sense!

FYI: Sewer ejector has to have its own , dedicated, vent, terminating above the roof. It cannot be combined with other vents. Are you sure that capped vent is not there to vent the sewer ejector ?

It is possible the roughed-in bathroom has vent already installed inside the wall. You will have to do some exploring, before you put new bathroom in. Would be great if you could take few pics of your situation and post it for our Experts to see, when you ready to proceed with the work.

In the interim, there is nothing wrong with connecting the capped vent into the septic line...

This capped off vent is most likely the lavatory vent. There should be a 2" pipe coming up out of the floor for a lavatory drain. Connect to that and the vent will have a direct connection to the sewer. FYI: Most bathroom rough the bathrooms in like this. (see image)
Good luck, Tom

Thanks again. Just to clarify, when I said the bathroom is "roughed in" I just meant the plumbing is installed in the basement floor - no walls yet. I looked in the area where a dedicated sewage ejector vent would be and I don't see one, so the capped vent I'm referring to MIGHT in fact be for the sewage ejector vent (although it seems to be in a strange place). Even if it is a vent for a sewage ejector, is it still okay to run it directly to the septic drain line for now? As requested, I took a couple pics and am attaching for review. The first pic shows the (future) bathroom section of the basement. The second pic gets closer and shows the vent pipe dropping down from first floor (left side of picture with blue at the bottom of the vent) and the capped connector to the septic drain line (center of picture in the background) I want to connect it to. Hope that helps.


Just one quick additional note regarding my vent pipe issue. We are not on a public sewer system, but have a private septic system. There was a previous response that asked about my use of the word "septic" and wondered if I really meant "sewage ejector" and I thought it might help to clarify that further. Again, thanks for the previous responses.

Dp2010...

Connect the 2" vent pipe into the drain line as you wanted to do... no problem at all... for now!

The vent in your picture looks to be the FUTURE VENT... required in all newly constructed homes in most states nowadays... you'll want to connect the basement bathroom vent(s) into this as you presented. This would mean that you need to run a 2" dedicated vent up through the house and out the roof for the sewage ejector...UGH!

In my area, we usually connect the FUTURE VENT into the drainage system. We mark the vent as a future vent (FV) and it can then be cut from the drainage system and run to the basement bathroom in your case (cap the drain fitting). If you can find a future vent only connected to the drain line then the vent in your picture would be the dedicated vent for the ejector pit. You would find this 2" vent pipe going out the roof uninterrupted.

If you have a 2" vent going out the roof you could send water down the vent. If water shows in the basement then the vent is meant to be for the dedicated vent for the sewage ejector. If no water, it is the future vent for the bathroom.

Let us know what you find... :)

Mark

Dp2010, thank you for posting the pics. Great help, indeed...

Looking at the sewer ejector, there is a white pipe going UP. That may actually be the dedicated vent for the sewer ejector. I can see a stub-out on the 3" PVC drain. That may be the inlet for sewer ejector discharge.

I am guessing here since the ejector is kind of far in the back... Do the water test as Mark suggested. Let us know how you did. Milo

A big thanks to Milo Delezal, Speedball1, & Massplumber2008 for the very helpful answers. Just FYI - the pit in the far background (pic 1) is our stormwater sump pump and the pipe going up discharges the water outside the house. The pit in the middle corner (pic 1) is for the sewage ejector (not installed) and would feed into the drain pipe directly above it. I could not find any other "future vent" pipe, so I'm pretty sure that's what my capped vent is. I have no idea why there isn't a dedicated vent pipe for the sewage ejector, but my wife says that's okay because she doesn't want another bathroom for our two teenage sons to get dirty. :) Thanks again for a great place to ask a question!

We're all glad to help! Take a few minutes and put some water down the pipe from the roof... confirm that the vent is a dedicated vent for the future ejector system. A vent for the ejector cannot connect into the plumbing venting system so be sure to confirm.

Good luck!

Mark