This past year, I moved into a house where a dog was a resident.  Elie.  Elie is a fairly large dog, so you can imagine the excrement that might come out of him.  I decided to start a pet waste digester. Pet waste can have a negative effect on the environment, by spreading diseases to other pets and wildlife, contaminating water sources, and leaving landmines for others to dodge on sidewalks and in parks.

With about 14 million dogs in Canada, finding a way to divert the approximately 620,000 tonnes of waste rather than throwing the plastic bundles of poop in the garbage to break down anaerobically and contribute to climate change (which let’s face it, already has enough contributors) is a great and easy thing to do! A New Zealand book suggests having a medium-sized dog is twice as environmentally costly as making a Toyota Land Cruiser and driving it for a year.

When walking your dog, you can pick up the waste in a plastic bag (compostable preferably) then flush it when you get home (not the bag of course), or you can empty it into your pet waste digester, along with your dog’s home poops wondering, can dog can eat cantaloupe?.  A digester allows your pet’s waste to be broken down by bacteria and micro-organisms in a contained area, reducing the harmful pathogens and contaminants, preventing these from being washed into our rivers and lakes, or leeching from landfills and contributing to climate change.

Here’s how you do it: you place a garbage can with the bottom cut off and holes drilled in the sides, in a hole you dig (be sure to call Manitoba Hydro and other utilities for line locating first!), place a layer of rocks at the bottom, add water and test for drainage.  You will need to add some septic starter (enzymes and microbes) and water to start the decomposition process, then start adding your pet’s poo and put the lid back on.  You should then monitor it and add some water, which also helps with the break down (gives bacteria a nice environment to do their business) and possibly more septic starter every week or as needed. If you aren’t able or willing to make your own system, there are pet waste digesters available to purchase.


Cat feces can also be added, but most websites recommend not adding urine with litter, as it will take a long time to break down.  This is likely more applicable to clay based litters, newspaper or corn based litter would likely be fine.  I flush my cat’s excrement (I use a flush able corn based litter), so I haven’t added any cat litter yet.

City Farmer states they add pet waste for years before it starts getting full.  This depends on how many pets you have, how much septic starter and water you add, and the conditions for your area (digesting stops when it is cold, of course). I just started mine in the Spring, so it is quite empty still. There is no smell and it is not in the way, it is actually quite inconspicuous.

Be sure to place the pet waste digester out of the sun if possible, and as far away from your vegetable crops as possible, as the plants could absorb pathogens if too close.  Mine is about 30 feet away from my vegetables.  Also, the end product is not like compost from your normal compost system, it will not be safe to use it to spread on your gardens.  Because pet waste can be quite dangerous to handle, we don’t recommend you handle what comes out of the digester.  Once my digester is full, I will likely stop adding pet waste, cover it up, and start a new system, leaving the first digester to ‘finish’ for a few years, then just cover the opening with soil and  grass seed. Watch Green Action Centre’s website for an update on the pet waste digester after Winter!

There are detailed instructions available on City Farmer’s website.