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where does all that food and drink go when you are off-grid, the composting toilet project

urine diverting composting toilet

I have been researching this composting toilet project for some time now.  I concluded that the magic to controlling odors is to separate the liquids from the solids, have a steady flow of fresh air that is exhausted high up above to the outside.  that, and a liberal covering of peat moss/sawdust.  the chamber above is sized so the large brown plastic container slides in/out easily.  that catch basin will be emptied to a solar assisted composter.  it's also sized so a five gallon bucket can also be used if necessary. 

12v dc brushless muffin fan exhaust

I'll use a 12 volt DC brushless fan to keep the chamber at a negative pressure.  the exhuast will be sent up and out through a four inch duct.  these fans normally cool the CPU on your computer. 

solar panel  

we will power that fan with the sun.  we now have a single panel for the smaller cabin and a three panel system will supply the bathroom and larger cabin. 


thanks for the suggestion. I am familiar with those flies as they already enjoy the kitchen compost pile at austinmodhouse. as for the wimberley off-grid house, we have a dry urinal and separate containment for most liquid waste, also the composting toilet has a urine diverter (for the womenz) , so liquids are separated before they hit the solids.

From personal experience, my I humbly offer a suggestion. When having one of your many soirees with friends and lots of liquid refreshments, the typical compost toilet is simply overwhelmed by an excess of liquid. This will usually result in attracting a very annoying sort of Drosofila (small fly) by the hundreds (great clouds of them if it is a really big party). Instead, offer the gents a piss bucket (or two), which you then neutralize, post-party, with chlorine bleach and an additional amount of water equivalent to the waste accumulation. Allow to vent freely in the great outdoors until all/most odor has disappeared (a day or two, depending on the amount of chlorine added). Then dispose of properly in a poison ivy, oak or sumac patch away from waterbodies. It beats having to deal with multitudes of little flies throughout your off-grid venue.


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