6" CI x 4" PVC

I've got a 6" CI sewer line coming up out of the basement floor, there is a 6" tee, and from the (righthand) side a 6" main that runs the perimeter of the basement wall joins in here, goes down and out.
Then there's the top of the tee where a piece of 6" cast iron still remains which is cut off to where about 1/4" sticks out from the hub. the super short piece must have been for a threaded cleanout plug or something (no more plug, and no visible threading left through the rust and grime)
What I need to do is join 4" PVC to this 6" cast iron, I was gonna use a 6" x 4" donut to do this, until I saw that the hub still had a piece of cast in it, the piece of CI doesn't stick out nearly enough to use a 6" x 4" no hub connector.

I have some idea's of what to do in this case, but wanted to see what someone here might recommend for this short of removing the piece of CI in the hub (if it comes to that what's the best method?)

As far as what this is for, some years ago someone installed a sump pump and ran the drain into this tee, used some sort of plastic 6" x 2" mortar mold and then filled that in with mortar to create a (poor) seal. What I need to do now is repipe the sump pump to make provision for a second backup pump.

I know sump pumps are supposed to be piped into a stormwater sewer or out into a yard (and in most cases required by code), but this is a 100 yr old commercial building on a commercial street (absolutely no yard to be found) and the only place for the sump pump to drain IS the sewer.

(I'm sure I'll get heat for asking this without the full details of what I want to do, but I have to ask anyway)

Assuming that stub is leaded in, remove it, then use the donut to connect what you need. A pro could probably knock that out of there quickly, but you may wish to drill holes in the lead until you free it up enough to pry it out. A wire brush to clean up the insides, then the donut and you're golden except for the next point.

Aside from that, legally, you may be required to connect the sump to the storm drain rather than the sewer which is another whole can of worms.

jadnashua said:

Assuming that stub is leaded in, remove it, then use the donut to connect what you need. A pro could probably knock that out of there quickly, but you may wish to drill holes in the lead until you free it up enough to pry it out. A wire brush to clean up the insides, then the donut and you're golden except for the next point.

Aside from that, legally, you may be required to connect the sump to the storm drain rather than the sewer which is another whole can of worms.

Click to expand...

I guess removing the stub would be the best way to go and most proper way to do the work I need to do.

The building has no storm drain, Chicago has no storm drain system at all. As far as I know the entire city is on a combined sewer system, which is why they have all the deep tunnels and underground water storage - so the water has a place to go before getting treated.

Perhaps a bigger problem is that last I knew, Chicago plumbing code does not allow the use of PVC below grade.

Unless this has recently changed, everything in a Chicago basement is C.I. for that reason.

There would be ALOT of repiping to do in this building if that were enforced strictly. (there have been many inspectors through this basement over the years) Previous owners did alot of botched plumbing work.