Big Dog Poop Composter (made From Salvaged Materials)





Introduction: Big Dog Poop Composter (made From Salvaged Materials)

With garbage dumps becoming full it has become very important to find an alternative to simply tossing your pet's waste into the trash. I have always liked the idea of composting my pet's waste, but didn't want to add it to my garden compost. That is why I decided to build a separate composter specifically for doggy doo. I had originally planned to purchase a dog waste composter, but quickly realized that I need a much bigger one than is on the market in order to handle all of the waste from my 70 lb. Labrador Retriever. Big dog, Big poop, Big composter. I decided to create this Instructable to help others deal with their pets waste in an environmentally sound manner.

Tools & Materials: All that you will need to build a waste composter is a shovel, a saw, a drill, 4" pvc pipe, and a vessel of some sort.

First find your vessel. I decided to use a salvaged plastic 55-gallon barrel and give it a third life. A 5-gallon bucket or a trash can would work if you have a small dog. Rather than recycling the barrel I simply reused it. I got it from our local coffee roaster and used it as a leaf composter for a couple years. Be careful that you don't use a barrel that may have had toxic chemicals in it. Mine used to be full of French vanilla flavoring. That stuff is fairly harmless.

I have also entered this Instructable in the Epilog Challenge, so please remember to vote.

Step 1: Preparing the Vessel

Take your vessel and drill holes everywhere except the top and bottom. Any bit size ranging between 1/4-inch and 3/4-inch will suffice. The holes need to be large enough to allow air to reach your composter, but not large enough to allow soil to fall through.

If you are using a barrel you will need to cut the top off. The open end will become the bottom of the compster. This will increase the surface area that is exposed to the soil and allow rain water to drain easily.

Next cut a circular hole into what will be the top of your composter. I cut a 4-inch hole into mine because I decided to use a 4-inch inside diameter (ID) pvc pipe as the access port for my composter. It's good to have a hole large enough to allow the dog waste to fall into the vessel without the need of a push-stick. The 4-inch ID pvc fits perfectly over the 4-inch hole without the danger of falling in. I was able to find a waste cut piece of pipe that was headed for the dumpster.

Step 2: Dig It

Next you need to choose the location for your composter and get to digging. An ideal place would be easy to dig, accessible, yet tucked away, and at least a couple hundred feet from any wells.

This is the most difficult step. Dig a hole large enough to fit the composter into it and deep enough to bury it a foot or so underground. Keeping the composter below the ground level will help keep it from freezing as easily during winter. Be sure to keep the topsoil separate from the rest of the soil.

When the hole is dug try the vessel for fit. Put a straight edge over the hole in order to get an accurate depth measurement. This measurement is needed to calculate the required pipe length.

Step 3: Access Port

Cut the pipe a few inches longer than the measurement made in the previous step. Place the pipe over the hole and carefully back fill the hole with topsoil. You could also use an old plastic planter or something of that sort rather than a pipe.

After back filling the hole the only part of the composter showing will be the stickup portion of the pipe. I plan to put a rubber cap on the pipe to help control any odors. You now have a pet waste composter that is large enough to handle the waste from a big dog and yet safe. Unlike other designs that I have seen, nobody will be able to fall into this one. Job well done.

Step 4: Drop the Poop

Now the fun begins! The composter is complete and ready to be put to use. If you are using corn starch based bags you can simply drop the bag into the composter, if not you will need to put the poop in without the bag. Adding small amounts of grass clippings will aid decomposition. Some folks recommend adding products such as Cesspool Treatment and Rid-X. I do not, the same bacteria that are in those products are naturally occurring in grass clippings. I design wastewater systems for a living and would not recommend such products even for your home system.

It should be quite some time before this composter besomes full. When the composter is full I can simply take the topsoil off the top and pull the barrel out of the hole. At this point I can either use the compost as lawn fertilizer or simply bury it. Either way we have already helped preserve a little bit of our precious environment.



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    88 Discussions

    I have 15 med to big dogs and would like to know if I can make a large composter using recycled plastic bottles? Thanks Lynda

    1 reply

    That's a lot of poop! The book "Humanure" may have some design ideas for you. I think I would dig a hole and have an outhouse-style hole with a lid so I could open the hole, drop in the poop, add straw or other high-carbon, low-nitrogen material, and a small amount of water. I would be trying for hot composting, but I would suggest getting good at hot composting before trying it with dog waste.

    After a year with this thing in the ground I decided that I had to move it in order to put a shed up.  I dug the soil from the top of the barrel and 1-foot down the sides. With some effort I was able to pull the barrel out of the ground.  After doing so I took a close look at the volume and condition of the contents.  The barrel was about 20% full and did NOT smell badly at all.  The bridgeable bags were not breaking down very quickly, but any un-bagged poop that had turned white and was very crumbly.  I am assuming that this composter would work much better with compostable bags or none at all.  Still, 20% full after 12-months with a 70-pound Lab contributing the poop seems good.  Especially since it froze this winter before decomposition could really take-off.

    Please keep in mind that I do not intend to remove the contents and certainly don't plan to put it on a garden. Although there may be nothing wrong with dong so.  If it becomes full I may move it to a new location.

    2 replies

    "After a year with this thing in the ground..." Thank you for the follow up! It helps to know some of the results. It is interesting that the "corn" bags did nto decompose. Thanks again, B.

    I have read that dog poop (likely cat poop, too), like human waste, needs a higher temperature for decomposition, and that such a temp. is not generally reached in a household compost pile.  In our municipality, we are encouraged to bring it in and flush it, so it gets treated with the sewage.

    You might want to consider setting up something like a compost toilet.  I think Mother Earth News or Cottage magazine had good instructions for building your own, or there might even be some here.  Once composted via this method, the results could then be used in the garden. 

    This is more accurately a simple septic system.

    But even if you compost animal waste you can use it on flowers, or even fruiting trees.

    I have a paralyzed husky and I collect his poop as he cannot do it for himself. I use cheap paper towels. My question is if I build this or something similar can I put the paper towel in with poop? I'm sure it will break down. Also I am not a finatic so I don't cut grass as often as most people and use that in my garden. So I may need to use some type of treatment.

    1 reply

    After reading through these I may have to alter the design as where my garden is it is good soil but the rest is hard clay. I have an above ground compost that has been there for years.

    My lab recycles her own poop by eating it. By the third time around she leaves it alone....In the winter she has a large selection of frozen doodies to chose from, like picking a choco bar from the freezer. Yum!

    1 reply

    The idea of gravel around the barrel seems logical to keep out dirt and to allow more air flow. I have morning glory which will probably take over anything I put in the ground. (I'd love to kill it off) With two dogs this seems like a sound idea. One question: You mentioned moving it after some time has past. Any idea now, after four yrs or so, how long that time is?

    1 reply

    What if the soil is soft, not clay, could you drill holes in a large 55 gal drum and with natural rain seepage, could it decay and leech into the ground? As long as theres no water for drinking around it, lol or downhill, lol?

    THANK YOU!!!!!!!!!!!!!

    I used an upsidedown 5 gallon bucket in mine.

    This sounds like an excellent idea. However, I would urge you to make one important improvement. Please attach some sort of screen device (removable or hinged) on top of the open pipe. A 4" pipe is large enough for several little animals to venture in out of curiosity but they will not be able to escape at all. I know if I inadvertently leave a nearly empty watering can upright, I can find a poor drowned chipmunk in it the next day.

    We have two dogs, a Shepherd and a Golden Retriever. When one of us on poop detail we just go around the acre lot with a small shovel and a plastic pail. Once the clean-up is done it would be easy to simply dump the content of the pail into the opening of the composter. No need for bags at all. The idea of adding a biological stimulater to the mix is a good one. Great instructable.

    LOVE IT! This is perfect I have everything but a lid for the pipe right here in the yard. Placement is an issue any problems with odor?

    Good day all

    Composting as best I can recall occurs above ground and includes a host of organisms including fungi some of which can be hazardous to your health when breathing particulate aerosols. A Septic tank is merely repository for waste, without aeration and piling layer of waste upon layer of waste the process will be slow. You might be confusing digestion with fermentation (in brewing accompanied with aeration and agitation).

    A waterless method that was designed to deal with human waste involved the creation of a box/chimney configuration that receives air naturally through convection from beneath, warm air rises through tiers of grids of varying gauges and leaves the device (with aromatics) via the chimney. The objective is to dry out the deposits rapidly. I saw this in design concept only.

    Certain pathogenic organisms dependent on moisture will not thrive. Wear a mask when handling as the dust will contain fungal and bacterial spores.

    PS. the ph of of the soil can be regulated by adding lime or alternative alkali's.

    Thank you.


    Brilliant! I love not having to add organisms to the naturally occurring ones. The less we mess with Mother Nature, the better. Thanks for a very readable, straightforward Instrucable.

    EXCELLENT Instructable!!! I see the last comments by Conky were 2 years ago -- if you're "listening in", could you give us an update on how the pet septic tank is functioning?
    Of all the plans for DIY pet septic tank I've seen, I like yours the best and am considering installing one. However, I have 2 Huskies and 1 Malamute, so I'm wondering if a 55 gal drum will be large enough. . .