It was in free space in the basement, next to a wall. Something like a slip joint (the under sink plumbing wasn't touched), a few feet of vertical pipe, a PVC t

It was in free space in the basement, next to a wall. Something like a slip joint (the under sink plumbing wasn't touched), a few feet of vertical pipe, a PVC trap with a few elbows, six to eight feet of lateral pipe, a 45 plus a few more feet of pipe, and a threaded adapter into the cast iron stack. It was close enough to the stack (or "grandfathered") that there wasn't even a vent involved. Care to revise your judgement?