People often ask me about our toilet situation. They ask as we are big on managing all our waste and saving water. Imagine!
Water is scarce here especially in summer. There is never enough compost on a farm either. Now why would we waste such a precious resource to flush away a valuable commodity just because we are too squeemish to deal with it ourselves? Doesn't make sense.
We went from an existing basic septic tank system to a sawdust toilet. (Actually we had to change as the acid water had killed all the good bacteria which processes the faeces in the tank). We have 2 buckets- 1 for solids and 1 for liquids. The liquids smell quickly and need to be changed after a couple of days. It's easy to process as it leaves the body sterile so we dump it on the first compost heap. That's about a 3 month processing time to usable compost with all the other stuff from the farm.
The solids smell less over time but need to be managed and processed a bit longer to ensure any bad bugs have been nuked. So far we have been digging holes for trees and emptying the solids bucket in the bottom. That's about every 3 days. I still have lots of trees to plant so I think we can keep going with this system for the next 6 months. Obviously this will come to an end and we will have to make a new plan. We intend a new long term compost heap. It will go for about a year. After 6 months through a summer, I will check the compost heap's temperature for several days. This heap will be used for trees and shrubs not for leafy or seasonal veg. It seems a bit over cautious but I would like to test it before it is used just anywhere.
There are several great books which cover the subject with all the science attached. The Humanure book is the most comprehensive and very educational.
I must say that while I like not wasting water and it has been very clean and un-smelly, emptying the buckets is a chore. We try to keep up the hole digging but with everything else we must do, it just takes too long. If we just had to tip it out that would be easier. The sawdust is readily available from a local woodwork shop so that's no big deal. We will leave it in place in our camp site and volunteer area as that doesn't have daily traffic every day of the year.
In our house we will revert to a septic tank of sorts. I must still find the details but it has 2 processing chambers and the runoff remains underground and will feed the nut orchard. Still not wasted but a lot less work.