Venting ejector pit to basement bathroom vent?

[curious_george]

I have a kitchen on the main floor and right below is an ejector pit that serves a bathroom(toilet/shower/sink) & floor drains. This is a 1950s house with a finished basement.

Here are the drain connections for the basement bathroom:

-> [shower drain{below concrete}]
----> [toilet drain{below concrete} + shower drain]
--------> [toilet + shower + sink drain{above concrete}]
----------------> section1{below concrete}: empties to ejector pit inlet
----------------> section2{above concrete}: 1 1/2" pipe going straight up

I assume the 1 1/2" pipe is the vent stack, and I assume the sink from the kitchen on the main floor ties into this vent as well. There's no roof penetration at the corresponding location, so it possibly vents directly into the attic or in the attic it shoots across the building into the 4" stack from the bathroom on the main floor.

Question is: can the ejector tie into this same 1 1/2" vent that the basement bathroom + main floor kitchen use? This is the approach one plumber wants to take. I've read threads related to this but can't get a clear picture if it's allowed under the Chicago plumbing code.

 

[NHmaster3015]

Nope, the pit needs a 2" vent

 

[Sponsor]

 

[curious_george]

Is that per Chicago code?

Would the ejector/bathroom/kitchen fixtures cease to work properly if the ejector pit is tied to the bathroom/kitchen vent? My plumber is the one suggesting it, but I just wanna be sure before spending the thousands he wants to fix it.

If it helps, I have some pictures in my other thread: https://terrylove.com/forums/showthread.php?56335-Identify-this-square-mass-in-old-ejector-pit

 

[Tom Sawyer]

I'm not seeing a vent, I'm seeing the pump discharge pipe

 

[curious_george]

I'm not seeing a vent, I'm seeing the pump discharge pipe

Correct, the pit does not currently have a vent at all. I just asked a plumber to install one(for sanitary reasons) & tying it into the bathroom vent is the approach he wants to take. Asking if this will simply work properly, and then if it is up to code.

 

[hj]

Chicago "code" unless it has changed in the last 40 years, was ALWAYS a 2" vent for a toilet. When you ask about connecting to a 1 1/2" vent, you have to differentiate between what is code and what will work, because the two are not always in agreement.

 

[curious_george]

Chicago "code" unless it has changed in the last 40 years, was ALWAYS a 2" vent for a toilet. When you ask about connecting to a 1 1/2" vent, you have to differentiate between what is code and what will work, because the two are not always in agreement.

So it will not be up to code, got it.

Second part - will it work?

I believe the toilet/sink/shower are vented through a "wet vent" that also connects to my kitchen upstairs.