We are finishing our basement and installing a bathroom. We need to install a Sewage Pump to lift the waste water to be able to tie into the main (gravity) drain located in the joists of the first/main floor. All of the plumbing in on the first/main floor is vented with loop vets and we do not have a main vent stack. I need to vent this pump package to an external vent. Anyone run into similar problems?