loading
Picture of Backyard Organic Waste Digester
I made this digester to divert our pet waste and a portion of our household organic waste from the landfill. It's pretty easy to make and it will save you money by reducing the volume of waste you must pay to dispose of.

This digester is basically a compost bin with a twist. The twist being that the bin is sealed and partially buried to deter pests from feasting on the stuff inside.

I do not plan to harvest any material from the digester since my compost bin provides enough humus for my soil-building needs. The other reason for not harvesting the digester's contents is that it will be comprised of some nasty stuff, namely dog poop and rotting meat. Yechh!

My inspiration for the project came from the website of my local government: http://www.compost.bc.ca/learn/factsheets/3digester.pdf


Let's get started!

 
Remove these adsRemove these ads by Signing Up

Step 1: Items You Will Need...

Picture of Items You Will Need...
- Bin with a tight-fitting lid
- Electric drill
- Holesaw kit
- Felt-tip marker

Step 2: Siting the Digester

Picture of Siting the Digester
The best place for the digester is somewhere with plenty of sun and away from food crops. Sun helps it break down the waste faster and keeping it away from food crops reduces the risk of pathogens making their way into your food. I put mine along the property line with about a 40 foot buffer between it and our garden.

Once you have found a good spot for your digester it is time to dig a hole. I made the hole slightly larger than the bin and about 8 inches deep. I'm sure it wouldn't hurt to go a bit deeper.

Step 3: Preparing the Bin

Picture of Preparing the Bin
step04.jpg
step03.jpg
Now that you've got a hole in the ground it's time to put some holes in the bin. These holes allow the decomposing material to migrate out of the bin and into the surrounding soil. The holes also allow worms to come and go as they please, all the while munching on the 'goodies' in there.

I used a 1-3/4" holesaw to make the holes. The molded supports on the bottom of my bin made it very easy to lay out my holes as you can see in the photo. You may have to use a different method to space your holes. Just make sure you leave enough material between the holes so as not to compromise the structure too much.

After you have drilled all the holes in the bottom, drill a series of holes around the lower circumference of the bin. Again I used the molded supports as reference lines to get the appropriate spacing.






Step 4: You're Almost Done!

Picture of You're Almost Done!
00-main.jpg
The final step is to place the bin inside the hole you just dug and backfill around the bin. I lightly tamped the soil down and then placed some rocks around the base. You can plant something around the base to help blend the bin into it's surroundings or embrace the bin in it's au naturel state.

Thanks for reading and good luck with your digester (if you make one - post some photos or comments!)

Cheers!
coffeegulper2 months ago

Why not bury the bin deeper so it doesn't stick out so much?

Zach.Ogilvie (author)  coffeegulper2 months ago

Sure, you could bury it deeper. I didn't go deeper because there are underground utilities and I didn't want to hit anything.

Cspudley9 months ago

I love this idea as we need a place to put all the waste from 6 dogs. My husband is worried it will fill to fast. Is this an issue, how quickly does it decompose? Thanks!

Zach.Ogilvie (author)  Cspudley9 months ago
Decomposition time varies but I would say it takes 4-6 weeks to break down. I occasionally add water which helps it decompose faster. With six dogs I imagine it would fill up pretty fast. Of course, the bigger the pooch the bigger the poo, so results will vary! The size of bin I use is just about perfect for our two small dogs.
ugreebo2 years ago
Just came across your instructable. Great post. So how is it working? Any problems with odor?
Mmjmama3 years ago
Check out bokashi.

Basically it's the principle of using probiotics. You can even make your own. Highly effective and highly recommended, especially for your setup.
Xenophon3 years ago
NIce.

I built a similar concept last spring to work as a composter from the plastic salt tank of an old water softener. I drilled the holes on the bottom and sides like you, but made them much smaller to keep the compost in. Sadly, I did not document the process.

It has worked remarkably well this year, with all of our organic kitchen waste going into it, as well as much of our junk mail after passing through a paper shredder. No odor or animal problems at all. The compost will go towards a garden I plan on starting this coming spring.
IMG_0326.jpg
Mar HK3 years ago
This is a great idea...now where to put one in my yard...
Have you had much problem with odour when the lid is on?
Zach.Ogilvie (author)  Mar HK3 years ago
The digester is new so no odours yet. I'm going to keep a close eye on it and I'll make an addendum to this instructable once I have some data. It was suggested that I dump in some dry material (sawdust, leaves, etc) to abate any odours that may arise.
This is great! I wish I had a backyard. :)
Zach.Ogilvie (author)  jessyratfink3 years ago
Thanks, and I know what you mean! I have been an apartment dweller for most of my adult life. We're in a house now and this is my very first yard.