We began with an old fashioned open pit outhouse. The same outhouse now is equipped with a Sunmar commercial compost toilet. So far It has been sufficient to handle the groups of people that have visited us. We also have an IFO one gallon flush indoor toilet that feeds an anaerobic methane digester modeled after a Chinese model. It's slated to run a propane refrigerator but until then first thought I'd use the gas on a thermoelectric Peltier Crystal to make electricity but it looks like it'll be used to heat water. Environmentally the Sunmar is a definite improvement and the effluent filter system on the flush toilet makes a state approved sand mound look like child's play. Both were installed in the early 70's so they are legal under the grandfather clause. State and Township rules have since clamped down so I can't design and build such things now Also if and when the drought hits, no more one gallon flush Swedish IFO toilet. I’ll switch to using only our commercial bought compost toilets. OR I have out back a bunch of prefab cut pieces of fiberglass. They get rosined together to make the ultimate high capacity compost toilet. I'd really like to get this design certified through some legal process if possible. I suspect it might turn out to be a masterpiece. The culmination of other people's work and design plus a little of my own added to it. The pieces are cut out of 2 floor to ceiling shower stalls, 1 floor to ceiling bathtub stall, and one bathtub. All are fiberglass. They’re ready to go together like a transformer robot.
This one is modeled after a Swedish Clivus Multrim compost toilet, no moving parts. It’s a slow moving glacier of poop and vegetable matter that flows down a certain degree slope of smooth fiberglass (I’m pretty sure it’s 30 degrees). As it slides down, it hits a baffle where it begins its first process of decomposition. As it breaks down it falls through the baffle into finishing chamber where it completes the composting process. That’s the mechanical basics of the unit but I'll add number of my own touches to add to it.
Suffice to say that gray and black water have different fates here. Showers sinks and washing machine water go through 11 filters that are invisible in the landscape except where filters #9,10, and 11 show enhanced verdant plant growth. The system is designed with the capacity to process gray water to either utility or potable use.
You cans see illustrations of the gray water treatment in the water resource section of this web page and a bit more in depth in the book, Off On Our Own