Making a Simple Solid Waste Dehydrating System

How Dry I Am . . . How Dry I Am . . .

With a bucket and chuck it system, you can simply pour the mixed pee and poop waste contents of your toilet onto a pile of compostable material and then cover it with more material and let nature do its thing. This is a common method of composting your waste in a permaculture way. Joe Jenkins has a nice system for doing just that. It is, however, impractical for use on a 1/4 acre residential lot, simply because of the size and the amount of compostable material needed to create thermophilic composting in the winter time. It also doesn’t have a means to sort out and manage any waste that may be suspected of being unhealthy, that is to say, waste that comes from a person who is demonstrably ill or suspected of being so. You need a processor that allows you to separate and process unhealthy waste more aggressively and cleanly as well as one that allows you to take advantage of the useful properties of your poop and pee separately.

Joe Jenkins’ well designed waste management compost system

The BoonJon garden system of waste management separates the pee from the poop from the mixing medium. You might ask yourself, why would you go to all this trouble. Well, with today’s mindset or should I say abject fear of human waste, you probably wouldn’t. But if you are interested in practicing a permaculture lifestyle or if you want to prepare for some economic or natural disaster, or if you are just curious about being self sufficient, then it is definitely beneficial to be able to manage your waste more scientifically. It may be desirable to be able to utilize the urine separately for fertilizing purposes. This is best done by keeping it in its liquid state and then mixing it with water to dilute it. In its undiluted state, urine can be stored in plastic jugs or pales and allowed to age if desired and it can be piped to the areas needing fertilization for maximization of its potential and control of any smell. This can be done using an inexpensive system of buckets, PVC pipe and concrete blocks. More on the BoonJon garden waste management system in another article.

5-gallon bucket and PVC pipe urine irrigation system

So why not just bury the poop in your compost. You can and you can feed it to your black soldier flies, but these methods rely on a long term breakdown of any pathogens. I would argue that for a little bit more work, you can assure yourself that the danger is eliminated. This system, if adopted widely in a community would eliminate the spread of pathogens and parasites that use poop as a disease vector. If enough people would adopt it here in America, then it would become obvious that most of the third world could benefit immensely from using this system.

In addition to being able to use your pee and poop productively, you can recycle the medium as well. In situations where medium is difficult to come by or economy is desired for whatever reason, this is a superior system. Once the medium and the waste are separated by sifting and once the medium is exposed to heat and UV rays and further dehydration, there is no reason it can’t be recycled and used again. It saves on having to buy or make medium and if you are mixing additives to it, like diatomaceous earth or coco coir, then it extends the useful life of those amendments many times over, especially diatomaceous earth which is a non-toxic, non-biodegradable insecticide. Reusing medium that contains DE will help eliminate insects as a disease carrying vector. Oral-fecal transmission is commonly spread due to poor hygiene, but before you think that it will never happen to you, consider that if you have ever had gastritis, (AKA the Hershey Squirts) there is a good chance that somehow you got poop in your mouth somewhere.

The solid waste should be processed as soon as it comes out of the toilet. Using a system of stages of “treatments”, you first want to dehydrate the solid waste by exposing it to the ambient air and temperatures. In the summer as well as in the winter, the solid waste will dry out almost completely in about a week using a BoonJon dehydrator. This removal of the moisture in the waste is the first attack on any dangerous pathogens. Since most bacteria and parasites that harm the human body need to live in an atmosphere that resembles the ambient state of the body, they will die of dehydration if allowed to dry out, just as would a human in the desert. This initial step will kill most or all of the harmful bacteria in a weeks time. The other factor that the dehydrator brings in is heat. The dehydrator has or should have a black exterior and if set where it gets large amounts of sunlight, the heat inside will rise significantly, often well over a 110 degrees Fahrenheit. or 38 degrees Celsius. Even at this small elevation, few organisms can survive more than a few hours or days at this temperature including parasites like round worm or hookworm.

A key part to your BoonJon garden is the dehydrator and storage hot box. Each represents a stage in processing solid waste to make it completely safe in short order. The dehydrator can be made from parts that are easily gotten at any large home improvement store.

You need the following item.

  • Plastic trash bin (here)
  • 8″ x 8″ x 8″ concrete block (here) or an empty gallon paint can
  • 12″ x 18″ x 3/4″ plywood base plate
  • 5-gallon plastic tub (here)
  • Metal grating from a small barbecue grill (optional) (here)
  • Plastic milk crate with approximately 1″ square holes in the bottom
  • 3 or 4″ PVC drain flange
  • 3 or 4″ PVC plastic elbow
  • 6″ PVC plastic drain grate

Cut a 4-inch ventilation hole in the top of the lid and a 6-inch hole in the back side of the plastic trash bin and attach the appropriate drain flange and drain grate with screws as shown below.

Set the concrete block or a paint can in the bottom of the plastic trash bin and place the wooden base on top of it. Place the 5-gallon tote on top of that and the metal grating on top of that. Finally place the milk crate on top of that. You can make a similar sized wooden box with a wire mesh bottom or line the sides inside of the crate with plywood to help direct the medium into the tote below.

The metal grating (not shown above) is optional but does make balancing the milk crate on top of the tote easier. I used one that came from a small barbecue set that I got rid of. Ever the pack rat, it seemed like it would have some good use in the future and it did. You can buy a 4-foot section of metal upper shelving pretty cheaply at Lowe’s and cut it down in size to fit. Now you are pretty much ready to do.

Empty the contents of the solid waste bucket directly into the milk crate and sift out the medium by shaking the crate from side to side.

Now watching your poop rise out of the medium is kind of gross but it will accelerate the drying process significantly if exposed directly to the air. If you don’t want to watch this operation close the dehydrator and shake it front to back. Some medium will find itself down into the bottom or the trash bin and you will have to occasionally empty it out, maybe once or twice a year. If you want to deter insects like roaches, add diatomaceous earth to your medium. I suggest doing this with any medium that you are using in any 1/4 acre lot BoonJon garden, permaculture type application. It won’t hurt anything if you don’t, but watching roaches scurrying around in the bottom of the trash bin is always a turn off. On the other hand, if you are a Buddhist, you may want to just leave them alone. Just another lowly creature trying to scratch out a living.

The C-Head toilet is designed for two adults. If used in this capacity, it should take about a week before it needs emptying. Two adults and two small kids, a little more every 5 days. Every week empty the toilet into the dehydrator and rotate the waste from the toilet to the dehydrator to the hot box. In one week you will have waste that can be handled much more safely. I have no qualms about handling the contents of the dehydrator with bare hands but if you are squeamish, use barbecue tongs. Leave them inside the dehydrator for storage. Your poop will resemble rock hard dirt clods at this point. Don’t handle your dehydrated waste in front of your crazy neighbors unless they are on the same page as you. Nothing remains behind on your hands. Wash your hands afterwards for peace of mind.

Hot box setup using two bins (one sifted medium and the other dehydrdated waste) and a shower door panel.

Which brings us to the hot box. The hot box does what the dehydrator does but for a much longer period and much more intensely. You might ask, why not just use the hot box from the get-go. Well you can if you are not wanting to recycle the medium or you can build a bigger sifter (see this cool video) and just wait and sift it all at once. But if you use the trash bin BoonJon dehydrator, it gives you more options for using your poop in a more timely, permaculture manner. For example, you can actually make portable rocket mass heaters out of used medium for heating your greenhouse during winter cold snaps. You can also save the medium for reuse but burn some of the poop to ash for composting or if you want to speed compost the poop you can crush it up with a tamper and mix it with your current active compost tower to expedite the process and expose the waste to thermophilic heat. So the dehydrator can be a good tool to have.

Please feel free to make comments or ask questions below. If you enjoyed this article, please pass the link on to others.

Copyright 2019 – C-Head LLC – All rights reserved.

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