My truck camper has pretty small tanks relatively speaking. 18 and 20 gallons if I remember right. If my washing machine or whirlpool tub don’t overwhelm the septic tank (they don’t) then my camper won’t either.
I also have a few advantages over the average homeowner with a septic system that allows me to keep a close eye on what’s happening (as unpleasant as that may be). When we built the garage, I knew where the old septic tank was, but we didn’t know where the leach field lines were. Well guess what? We found them, right where we wanted to build the RV bay! Dug right through them when we were digging the footings.
So, a new leach field was installed further down hill, using about 300’ of “infiltrator chambers” (I’d never heard of those before) and occupying an area of about 50’ x 75’. I know where the D-box cover is, and I check in there regularly. If there was a problem (like for instance solids getting in there) I’d know it.
I obviously also know where the new septic tank covers are, and I check in there regularly too. That’s how I knew there was something wrong with the inflow pipe.
:):)