Hello,

I recently ripped out a large soapstone sink from my basement, due to poor appearance and leaks, and would like to install a smaller utility sink in its place. I am concerned to re-use the drain, giving it is separate from my septic stack and I am not sure where it actually drains (The few times I used the old sink it seemed to drain quickly). The pipe is made of cast iron and is roughly 2" thick (see attachments). Is it safe to install a new sink using this existing drain (with a new trap of course)? Is this pipe connected to town sewage beyond my foundation, or simply draining into some exisitng septic/leach? Thank you in advance for your help.

Bryan

Hi Bryan...

My guess is that the old sink connected into a DRYWELL of some kind just outside the foundation wall. Obviously it is still working and not filled in over the years or that sink would not have drained well as you said it did...

Legally, if you plan to put anything but clear water down the drain, plumbing code would want you to update this and install a LAUNDRY TRAY PUMP for the new utility sink. Plumbing code would require a new trap and also a new 1.5" vent for the sink. The new vent would connect into another 1.5" vent in the basement or upstairs, OR if codes permit in your area you might install a mechanical vent (called an AAV), but either way the new sink would require a vent.

The laundry tray pump would require a vent and the waste line would need to connect into the drain line... perhaps into the cleanout in the picture as long as you install another full size cleanout on the end of the existing drain. Technically, a plumbing permit would be required for all this (electrical too if no electrical outlet nearby).

Otherwise, if you want to just work with what you have you can give it a shot and if it lasts for years trouble free then you are all set. If you need to disconnect and go the pump route in the future then you do it then... ya know?

Anyway, my job is to tell you what a plumber would be required to do. What you as a homeowner decide to do is up to you... ;)

Let me know if you want to discuss a bit... glad to help!

Mark

Thank you Mark, your answer was very prompt and informative.

Hi Bryan...

You are welcome! :)