Yes, this is true in a septic tank in the ground! It can not be "hauled" in a METAL tank for transport in that state, in case of accidental spillage.... It has to have a neutralizer added which makes the contents of the actual tank "hot" I was not speaking of the buried Septic tank, I was talking of the truck with a tank fulla ****.....
This is called Detoxifying. The chemical reaction to the bacteria in the contents creates the temps....Which detoxifies the whole lot for travel. Just temporarily....
Durring travel they aren't trying to digest the solids at all......At that time its a bit to late as its removed from the septic system of that property,. its being removed to empty the local septic tank(s) where that solid will be injected into another much larger septic system or plant to then begin the digestion all over again!
This is from the days I worked for a local school district as a Building & Grounds supervisor, it was a nasty job, but every year I'd have a sewage pump company come in to drain the whole system so that it could be maintained and limit issues throughout the "school" year and this was what I read in the paper work for our local state laws concerning sewage removal, and treatment.
