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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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.


conky (author)2010-04-07

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.

WilliamB105 (author)conky2017-09-06

"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.

ourmoneypit (author)conky2010-04-12

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. 

lyndamay (author)2016-06-05

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

ThomasP5 (author)2015-01-13

I have read that you shouldn't compost dog poo

MattM215 (author)ThomasP52016-05-22

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.

Grey1wahyah (author)2016-03-01

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.

Grey1wahyah (author)Grey1wahyah2016-03-01

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.

WANTONSOUPGUY (author)2011-07-15

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!

Good one

kwhitacre (author)2014-11-08

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?

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?

dumpstar (author)2014-11-06

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

I used an upsidedown 5 gallon bucket in mine.

m1m1 (author)2014-07-17

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.

pstevens2 (author)2014-06-08

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.

Hippykidz (author)2014-05-07

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?

ingwe01 (author)2014-01-11

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.


MsCenturio (author)2013-08-01

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.

jimg2k (author)2013-07-07

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. . .

rayleb (author)2012-05-15

Well I'm about to make a big mistake I guess. I have been composting leaves dog poo and grass for a few years. I just got through tilling into a 15' X 15' area for what was intended for corn. The composted mix is about 1.5 foot deep. Does anyone know is this dangerous for planting food?

st_indigo (author)rayleb2012-11-30

You should NOT use pet or human poop compost on fruit or vegetable crops, though tree crops are okay.

1983746758937219 (author)2012-11-27

I have a huge backyard. Should be an interesting project with all the dog poop back there.

ElmoRoyD (author)2012-04-09

i have to ask again, how is this going?

im about to have my own house with a backyard. Finally.

jennybean42 (author)2009-07-17

When I went to girl scout camp, the nurse would go around every week and pour a mixture down the latrine to help it decompose faster... I asked her once what was in it... I wish I could remember the recipe, it was brown sugar, yeast, water, all organic things, but I don't remember it's been 10 plus years. If someone could find that recipe, I'm sure something like that added to the system every once in awhile would help with the decomposition. One wouldn't want to use this for "garden compost" but it would be an excellent septic system rather than the "no man's land" we have in the back of our property!

HaShe (author)jennybean422012-01-21

I live in a developing nation an none of the over the counter products are available. I found this:

StuNutt (author)2010-04-11

During my first season at this location, and with 3 cats to cope with, I dumped the cats'-dump on my compost heap.  It didn't seem to decompose very well!

What do you guys do with the products from cats?  I've had to stop them half-burying it where I am trying to grow a lawn (wire mesh), and they don't seem to be very adept at the burying concept anyway - they just seem to dig a hole, dump 3 or 4 inches away, and then dig another hole but miss the first hole  with the diggings!

The UK BaconSalt Man

NaturalCrafter (author)StuNutt2011-04-18

We used to have two bombay cats. One would go indoors and use the cat box and nowhere else, and the other hated the indoor catbox and only go outside. Even if it meant my flower box in icy winter. She would use the cat box If she had to but preferred fresh dug soil. So when I first started my garden beds I had to put plastic chicken fencing over them. She hated stepping on that or the black fabric mulch both turned her off. I would compromise and scratch up an area where her poop would not hurt next to bushes or back of garage and she was grateful for the dirt to dig in.

HaShe (author)NaturalCrafter2012-01-21

Have you tried to make an outdoor litterbox? I found instructions on the web and made a small one. Instead of store bought litter we sprinkled w/ some fine gravel. It is easy to clean. Our neighbors are happy bec. the cats don't go in their yards eithe.

La and Mike (author)2010-05-06
Look up 'black soldier fly larvae'.  These guys will eat poop like it's $500 dollar chocolate!  I am convinced these are creatures sent from another universe-they eat all kinds of human-produced garbage, and then turn into a non-biting, non-filth-and-disease-spreading fly that zips off into the sunset.  I had a bunch in my garden at the end of the season last year, and we would dump everything short of beef bones in, and by the next day there was nothing left!  When the birds and lizards discovered them, they kept the population down a bit, but I still ended up with a little extra compost in the garden.  Wonderful critters-I would like to build some type of containment system, so I could harvest the larvae and put them in my outdoor-bird feeders!
dreiseratops (author)La and Mike2011-10-03

Another universe hah :)

HaShe (author)2011-01-28

Have you city dwellers ever thought of just flushing it? It will go to a treatment plant and be processed. This might be better than the landfill.

I'm going to try this with cat poo.

dreiseratops (author)HaShe2011-10-03

I did that a few times when I was a kid when it was part of my chores.
After a while my mom saw me do it & totally yelled at me.
I couldnt understand why. :)

Just Bill (author)2011-08-25

My guess is that nightcrawlers (which travel deep) are going to keep that thing from ever filling up ... the more food you give 'em, the more nightcrawlers you get. No need to do anything special ... natural processes on auto-pilot will handle things just fine.

Beautiful how that works, no?

That's why the world isn't covered 3' deep in dinosaur doo-doo.

May I suggest, though, that In your next iteration of this design, don't bury it so deep ... and make holes in the top few inches to accommodate ordinary earthworms, too.

NaturalCrafter (author)2011-04-18

A system like that works pretty well in sandy or silty soil but not in hard soil.
I have a big lab and we bring it inside but our water bill has doubled. He goes too much to try and dispose of it otherwise.

corioreo (author)2011-03-04

Conky - please take a look at the Park Spark Project - a friend of mine headed it up in Boston, and your Instructable really reminded me of it:

conky (author)corioreo2011-03-07

Great idea. There is a good chance that we can do something similar with the sewer gasses too. Green Mountain Power uses cow manure to produce methane to run generators that make power for the grid. One hurtle for doing this on a small scale is the need for a scrubber to remove the acids from the gas. It will breakdown whatever is using the gas otherwise. I have even heard of people capturing the gas from their septic system to use in a natural gas stove.

calikoala (author)2009-07-23

I am going to guess you have never pulled one of these out of the ground? i can bet you probably don't want to use what comes out of it for any food or garden purposes.. and I'm sure you will be unpleasantly surprised by the smell when you pull it out not to mention a 55 gallon drum half full of poop will be pretty darned heavy. what is the time that these need to remain i the ground to allow the decomposition? If you are adding daily or very frequently, how are you getting the mixture to combined so it breaks down? I would think it will just compact to the bottom of the barrel and end up just being a huge barrel full of pop that needs to be taken to the dump in one large clump?

mz anne thrope (author)calikoala2011-03-04

The barrel would not be heavy because one end in cut out in order for the "stuff" to compost into the earth. Water and grass clippings add to the composting factor.

teslafan100 (author)calikoala2010-03-19

yea how our you gonna get the poo out?

digimancer (author)calikoala2010-03-14

 Sadly I have to agree with [[calikoala]], there are several other above ground instructables on here that make quite a bit more sense. Oh and lol huge barrel of poop! 

plumber4 (author)calikoala2009-09-17

I'm going to guess that you've never read an instructable. If you weren't so busy trying to be look for flaws in other people's instructions, you would have taken the time to read. Nothing will pile up at the bottom of the barrel because there is no bottom. The author never said or implied that you could use this waste for garden fertilizer. Maybe before you try to prove people wrong, you should at least take the time to read.

gemtree (author)2010-12-05

Seems to me to be an excellent idea for any type of compost.

jondonna (author)2010-11-29

What about using this for a small flock (3-4) of chickens?
This would work for any animals waste, correct?
Just to scoop out the poo once a day and put it in the composter?

Preston .s (author)2010-10-06


cloneboy (author)2010-07-19

I'm nowhere near an expert, but it seems like you might want to be sure to balance the nitrogen content of the dog manure and grass clippings with lots of carbon. Dead leaves would probably be good, though my readings say sawdust would be best. Shredded newsprint would probably be good, too. Though written for composting human excreta, I highly recommend The Humanure Handbook as a reference.

Smalfrii (author)2010-06-07

what about the bags? i would think that, unless you are using compostable or no bags at all, the other bags would just sit and slow down the cycle. Also plastic bags take about 500 years to dacompose, so you would just be partially reversing your purpose for the composter

dombeef (author)Smalfrii2010-06-25

Did you read the instructable? Is says that she used corn based bags to compost

Smalfrii (author)dombeef2010-06-25

oops my bad i guess i accidentally skipped over that. thanks for pointing that out

dombeef (author)Smalfrii2010-06-26

Yeah yourwelcome!

patriciasaulnier (author)2010-05-14

We have two huge dogs - a pyranees and a shepherd - and I really love this idea.  I would assume, with the bottom cut off, that as the doggy doo decomposed, it would slowly desolve into the ground.  Could you also add some water along with some grass clippings to help the process?

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