My current unfinished basement was never roughed-in for any plumbing. I am in the planning stages of getting the basement finished and am curious as to what I am in store for if I want to install a 1/2 bath and a sink for a wet bar. Here are some pics of the current plumbing in the basement from the upstairs levels (kitchen sink and 1/2 bath on first floor, two full baths one of which has separate tub and shower as well as a washer/dryer on second floor).
I'd get ready for some jackhammering. I'm not sure why there is a sewage pump there unless headroom was an issue or something. maybe there is a floor drain by the furnace.
It makes no sense for there to be an ejector pump installed, along with what appear to be vent pipes rising out of the floor, unless there were some underfloor piping installed, UNLESS there are fixtures in another part of the house that had to be dropped under the basement floor to the ejector in order to allow them access to the drain system.
There is something screwy about this. With all the existing horizontal drainage piping present there is no reason in the world why anything form upstairs should descend to slab level unless there was just laziness involved. Was there any bonus are attic bath conversion done sometime after initial construction was complete? If so is it possible that the plumber for the addition just tied into the basement future stacks rather than go to the trouble of cutting into a "used" soil line. If this was the case and this is wild speculation then he would have to be treating the 2" as a waste stack vent for the sumps sake. Also, if this scenario is even close to reality then it would have given the unscrupulous or possibly simply ignorant plumber the opportunity to sell a pump/installation along with the other work. I have no idea what happened here but that is the best explanation I can come up with for the given information and what I see. Talk to the builder and see if the basement future bath was planned as a full or half bath. If full then there should be at least one more stack probably covered by a black box or possibly a bucket buried in the concrete with just a small amount exposed. If it was only a future 1/2 bath then the 3" could have been for the toilet and the 2" for a lav, although they seem a little far apart and oddly oriented. Also the water heater and hvac are in the middle of it all.
I just noticed the floor drain that the hvac condensate line is discharging to. This may simply be a floor drain or was it originally for something else and has simply been converted to a floor drain? What is the distance between the floor drain and the 3" stack? Was there some kind of mid stream change in the plumbing construction plan for this house?