I have a septic system at my house. I also have a macerator/Y-valve set-up on my 28' cruiser. I keep my boat in a shed at the house - it lives on a trailer. I also have a rule on my boat - "Except in an EMERGENCY - no pooping in the shitter!" In those rare emergency situations, I rigged up a fitting that attaches a 1" hose to the thru-hull (macerator output) and runs it to a fitting on the hatch of my septic tank. Position the boat/trailer near the septic tank, connect the hose, open the thru-hull gate, flip the Y-valve, turn on the macerator and ... Bob's yer uncle! When it's just #1, I just dump it in the yard where I need a little "fertilizer". Of course, after dumping, the thru-hull gate is closed, macerator breaker is pulled and y-valve returned to vacu-flush.