If you are the original owner look on the print.
Builders don't normally give you extra stuff.
Foundation guys could have just made an error.
Ask the building department of there is a code calling for something like that.
All good ideas. Thank you! I don't believe I have detailed blue prints, but I'll look around. I also know the builder is still building down the road. I may swing by and ask the super if he knows.
Good idea as well. I guess I'll know when I measure the depth of the hole. Not sure what you mean by 'look inside the foundation.' I can't get under the laundry room.
Laundry room is in the interior of the house. Not sure what you mean by 'stem wall,' but the hole is below the top of the foundation slab, so unless there's an abrupt 90* upward, the pipe is going thru the foundation. I'll know more in a couple hours.