The composting toilet is nearly completed. The wooden toilet box has been completed and now has a glossy finish, and the toilet seat has been attached to it.

The glowing blue center is the light from down below reflecting off the PVC pipe in the center. This effect will be gone once we close the doors on the chamber down below.

The the left of the toilet (mostly hidden in the shadows) is a bucket that will hold the sawdust or shredded leaves or other cover material. After every “number two” (defecation) the toilet user will take a scoop or two of the cover material and drop it down the shoot. That’s it. No flush, no wasted water, no polluting the environment. Just feeding the worms in the composting tank down below. 🙂

As for “number one” (urination), we are going to install a shaped funnel in the front of the pipe to divert the urine to another container. It should look something like this:

The funnel will divert the urine into a tube that will drop it into a different container from the one with the worms. My current idea is to install a dripper valve on that container so that the urine drips out at some slow rate that is still fast enough so that the container never fills up. The urine dripping out is mixed with a constant flow of water at a 1:20 ration (20 volumes of water for each volume of urine). Then the diluted urine follows a dripper tube underground which slowly releases this “human fertilizer” to the roots of a bed of plants nearby.

According to a number of articles around such as this one from Scientific American, studies have shown that human urine used as a fertilizer is as good as industrial fertilizers while still saving the energy required to process the sewage it would otherwise have become. I dilute it 1:20 since the urine itself has so much nitrogen and phosphorus that it would burn the plant roots.

And if I can make the dripper system work properly, it would run automatically without any human involvement other than to check every once in a while to make sure it is still working. (I’m not that squeamish, but I’d still rather deal with the stuff as little as possible.)