Tree bog septic composting thing

I've bought a 140 year old farm house on some land about a year and a half ago and have been renovating it since then. I finally have it livable, but yesterday my waste line to the septic clogged up. Turns out tree roots have penetrated and crushed it in several places. I'm going to have to replace the entire line. This whole ordeal has got me back to thinking about composting toilets, outhouses, and other human waste alternatives. Everything I researched thus far had several pros and cons. I like tree bogs.. but I want to be able to gather and use the compost elsewhere on my property. this rules out the traditional tree bog as well as traditional outhouses and the arbor loo. But I don't want to handle fresh human feces and add the extra work of having to dispose of it via bucket. When I have to go I want to be able to go and be done with it.

I like the idea of having a dedicated outhouse in a beautiful hidden grove of feeder trees where I can enjoy my time on the john in peace, listening to the birds out of doors. I look at the tree bog with a certain amount of romanticism. So I decided to try and come up with ideas to combine things I like about other systems with the tree bog.

My goals:
- Tree bog atmoshpere + some of its functional benifits (filtration, conversion, soaking up liquids etc.)
- The ability to collect finished compost straight from the deposit site.
- Solid/liquid separation

I'm sure it has been done and discussed elsewhere, but I had an old book that described a compost toilet system built into the outside wall of a house where there are 2 holes above 2 separate chambers. One hole would be used for a time while the other was closed off, then the toilet seat would be moved to the closed hole and the previous hole would be closed off. Before switching back again the now composted matter in the first compartment would be gathered. This seemed a clever way to maintain the output of a compost toilet with far less labor input... Why carry the matter away to compost elsewhere when it can do the same thing right where you dropped it?

Then there is the matter of separating liquids and solids... and the system I know of that does this the best is the modern septic system. Waste falls into a tank, and the liquids drain out into a leech field leaving the solids behind to decompose via bacteria. Unfortunately we then have those tanks pumped out and removed from our property, and they always contain fresh night soil.

I have come up with a concept for combining these three systems. And I would very much like the input of the permies community. I want to build an outhouse on top of a stone foundation with an opening in the back. The foundation will contain 2 chambers. There will be a hold dug in the foundation that will be filled with gravel to ground level. This will act as a way for liquids to drain downwards and separate from the solids. some sort of permeable barrier should be placed on top of the gravel to prevent wet solids from sinking into it and clogging it up. At the bottom of the whole there could potentially be short lateral lines for further drainage. To me it makes sense to cover the openings to the foundation with square hay bales because they will add carbon, prevent leaching out the opening, and can be easily removed and replaced.

Have a look at my diagram, apiologies for the poor quality, I do not own a smart phone and the only camera I have is the laptop webcam.

Please let me know what you think, I would like to have a discussion on this concept and design

There is plenty of information about these things around, and yours looks similar.
Good luck with it.

Riley, to me it sounds like your idea is certainly possible.  You may not need a twin structure or twin hole if you use something akin to a rotating barrel design under the tree bog similar to that used in the Alaskan Bioshelter Toilet design (plans).  Underneath you could borrow from the layered media concepts used in vermifilter toilets such as shown on here, here, or here.  You would want to make sure you're not too close to groundwater though.

Worms could reduce your volume more than without, but worms also improve the overall quality of the output in terms of ensuring pathogen destruction, promoting beneficial biology, and creating exudates that build soil macrostructure.  You do have to keep them warm though.  What is your climate?

In what form do you plan on distributing the compost?  As compost, compost tea, or compost extract?  If you're using compost tea the soil biology is multiplied, which could compensate for less bulk.

P.S.: Honestly, I think you could distribute tree bog compost anyways, as implied here.  You could just ensure that at least one side is planted with things you could mow down (for access) and that the structure doesn't prevent access.