RV dealers in Greensboro, NC, will tell you right off the bat the plumbing that comes installed in an RV is limited. Because your RV is a house on wheels, the waste you flush down the toilet wonít get rid of itself. The same goes for other forms of sewage. You have to carry all of this out and dump it somewhere appropriate. Itís best to do this regularly because the extra weight can create a toll on how many miles youíre able to cover per gallon.