We utilized two vent holes in the top of our cave to push five sticks of 4" X 10' pieces of white pvc.  This main trunk leads all the way down and works as our whole house vent.  The in floor waste water pipes run in a retangular horse shoe with possible stack access on both corners of the home.  The front left and the back right. It will some day allow for the small bar unit on the third floor. 

I like working with new construction when it comes to plumbing.  When we purchased Caveland there was a working toilet in the "Middle Chamber".  We found out at our first party that it was only partially working.  Seems that as soon as four or five flushes in a row the whole system would back up.  We also discovered that at a party nobody bothers to metion it.  Also we discovered that the bathroom did not have any floor drains.  Oh what a mess that was.  Would have taken the prize for most disgusting clean up.  But Curt just had to take it one more level. 

Dough, Curt & Waynne had carefully cut open the concrete floor the full path of the exsisting plubming and future plumbing paths.  The old "orange pipe" was still in place mixed with cast iron.  Everyone was gone and Curt was doing a final look over to be ready to put all the pipe togahter the next day.  En route to tent world Curt slipped and dropped in to the pit.  doing this move the twelve foot tail piece just enough to cause a small leak at the corner. Curt without any thought or reason decided to complement his first mistake he would quickly put the pipe back where it was.  As if to hide his goofy deed.  As if no one would ever know that he had clumsily fell in to the pit.  When Curt moved the pipe pice back it snapped the whole pipe.  Out poored over 30 years of backed up nasty.  No one but Curt was there to clean it up.  By the next morning when Doug and Waynne arrive, Curt had the plubming  mostly glued.