Black tank mounting

[eagle19952]

Our bus has about 1/2" for 6' run. For commercial and RV parks we used under 2" per 100' for feed and under 1" per 100' for field.  
4" pipe is great for 4 bedroom house, or tying a run of spots together, but small house, bus, or RV spot only needs 3" to keep volume of water under poop...

you are right..i misspoke, mine is 3 inch 
but the drop is as i said

[kyle4501]

While a macerator pump is not a necessity, it does allow use of a small 3/4" hose to direct the waste up hill as needed. Easier to drain the tank when you aren't limited by gravity.
Sometimes, a splurge expenditure makes sense when you look at the big picture. . . .