whitebb2727
Well-Known Member
I can't be sure that it never needs pumping.There is always an irreducible residue. A well-running septic system doesn't need frequent pumping, but not zero either. Like compost: there is some mass that doesn't get turned into carbon dioxide.
Mind you, I'm deducing this on general principles. I don't have specific knowledge here. If I'm wrong, let me know.
I do know of them personally going many years without pumping if setup right.
Every tank we had was a large tank and properly maintained. They can go a long time without need of pumping.
There are variables to it but a proper tank with adequate size won't need much pumping.