We set up ours this way:
Our basement floor is lower than the sewer line going out to the sewer under the street. The builder installed a crock in the basement floor for the water from the washing machine and laundry sink. The crock has an ejector pump that pumps the water up to a level above the sewer line and connects to the house's drain pipes.
I installed a 1-1/2 inch PVC pipe that goes through the outside wall near the RV, across the basement ceiling (at a pretty good slope) and then goes down into the crock.
To dump the RV, I use a sewer solution and stick it's hose into the PVC line.
Everything except for the small capped PVC pipe on the side of the house is inside. When we dump, the RV blocks the view of what is going on. Nobody's business but ours.
Works for us.
