That's a good point on the septic dump and something to keep in mind for sure. I septic tank with several partitions would probably be OK, but definitely something to talk about.
I recently had a clog going into my tank, and there was likely 30 gallons in my main line. So when it finally broke loose, I essentially had the same scenario. No problems yet, but I can't exactly look at my leach field and see how it's doing.