In this area the trend is to pump completely and then return the liquid thus actually the only remove the solids.
In this way they can pump more systems per truck outing.
While this sounds reasonable to me, I wonder how widespread is that practice.
My concern is that in the day or so following this practice I wonder how much suspended muddy particles make it to the field which could saturate it and deter absorption.
True that having removed all solids the tank level is down and presumably low enough for suspended particles to have settled before the flow restarts to the field.
At least I hope that's what happens.
Either way I try to limit water usage for the 24 hrs following pumping. (no laundry baths etc)
And speaking of truck outings, as an association we conduct annual blitz campaign and our pumper service passes on his fuel savings thus keeping the fee in a more reasonable range.
Generally about a $25/30. saving compared to a one of call.
We have used the same service for some 10/12 years (but have compared but never changed) as they have proven themselves to be honest and straight forward and haven't come up with 'addons' like extra hose etc plus they do all the required paperwork required by the city for conformity.