Venting a Basement bathroom

Can someone explain how the venting would look for this basement stub-in?



The above image shows the layout, the line marked “sink†is what I hoped to use for the sink drain. But, there is also another 2†line by the toilet. There is also a line above marked “future vent†that is either 1 ¼ or 1 ½â€.



You can see from this image everything drains into and ejector pit


The vent line is just above the line I have marked for the sink


Shows the plumbing above the stub-ins. I have the ejector drain and vent labeled backwards on the image

I suspect what you have labelled sink is the shower vent and the plumber intended to drain the lav into the WC vent (the one marked "??")...

I just talked to the plumber that did the installation and thats what he said. But, he also said I could use either line ("sink" or "??") for the bathroom sink. They would both tie into the vent above. He also said the ejector pump venting was ok. Every place I read the ejector pump should have it's own vent going out the roof.

In my town, ejector pump's allowed to loop into main vent.