Dog waste is unpleasant and can spread parasites and disease. There are an estimated 70 million pet dogs in the United States and another 85 million in the European Union. The average dog produces about 150 pounds (68 kilos) of waste each year. That adds up to an enormous amount of poop!
Obviously we can't leave all this dog waste lying around, but what is the most eco-friendly way to dispose of it all?
Bag it and bin it
Most dog owners collect their dog waste in plastic bags then dispose of it in the nearest bin. This is great - it gets it off the street. But what happens to the waste once it leaves the bin?
Well, some of the bags end up buried in a landfill site where they and their contents will remain for many years - plastic bags can take hundreds of years to degrade. Increasingly, municipal waste is being incinerated in waste-to-energy plants, which is more eco-friendly than landfill but still controversial.
If the dog waste is going into a household bin this can cause a problem, as it will start to ferment in the plastic bag. Many councils now only collect refuse bins on alternate weeks, so the dog poop could potentially be sitting festering in the bin for up to two weeks.
Hopefully in time there will be more schemes using small scale anaerobic digesters to produce energy from organic wastes, like the dog-poop-powered street lamp in this article which will run for 2 hours on 10 bags of dog waste.
But in the meantime most of us just have to bag and bin our dogs' poop. So, which bags should we be using?
It's a confusing mix of degradable, biodegradable, corn starch, oxo-biodegradable, exo-biodegradable - the list goes on...... and there's no such thing as an eco-friendly bag of dog poop, no matter what the bag's made of!
There is no definitive answer. Amongst other things, it depends where it's going to end up. Your local authority's web site should tell you if they are using landfill or incineration.
If your knotted bag of poop is going to landfill, it needs to be in an oxo-biodegradable bag with no added corn starch or other plant materials. Oxo-biodegradable plastic fragments then biodegrades to CO2 and water in landfill while there is oxygen present, then becomes inert when conditions are anaerobic (more detailed info here). For example, see *Pogi's Poop Bags.
Bags containing corn starch or other biodegradable plant based materials continue to break down in anaerobic conditions in landfill, producing methane which is much more powerful as a greenhouse gas than carbon dioxide.
If it's going for incineration, there's more of a choice. You could re-use any plastic bags - bread bags, frozen food bags, carrier bags - at least you know if you've filled them with poop and sent them off for incineration, they aren't going to end up as litter or in the ocean!
Alternatively, we need to support the companies who are trying to do right by the planet, so this is a good time to cut the plastic and use those plant based eco-friendly bags. Read the box though - a lot of them aren't as planet friendly as they make out. Check if they tell you which environmental standards they comply with. They should at least say they are certified to EN 13432 (EU) and/or ASTM D6400 (USA). For example, see *TSP Premium Poop Bags, Pet N Pet, and *My AlphaPet.
When you dispose of dog or cat waste at home in the UK, most Local Councils say it should go in the bin with your general household waste. Some ask for poop to be double wrapped to protect their workers and also to prevent smells. They suggest picking up the poop in plastic bags and collecting it all in a small bin lined with a larger bag such as a supermarket carrier bag.
You can now get flushable bags, so dog mess can simply be put down the toilet and flushed away off to the sewage plant to be treated.
These are made of Polyvinyl Alcohol (PVA), a water-soluble alternative to regular plastic. The manufacturers say the bags break down quickly and harmlessly in the water. PVA does dissolve over time in water and is then broken down by bacteria into carbon dioxide and water. The bags are also certified as compostable, but only in industrial composting facilities that accept pet waste.
The US Environmental Protection Agency say on their website:
“Pet waste can be a major source of bacteria and excess nutrients in local waters. . . Flushing pet waste is the best disposal method. Leaving pet waste on the ground increases public health risks by allowing harmful bacteria and nutrients to wash into the storm drain and eventually into local water bodies.”
If you intend to flush dog poop on a regular basis it's worth checking with the water authority in your area as not all sewage treatment works are the same.
Never flush cat waste as this may carry toxoplasma gondii, a parasite which is not removed by sewage treatment and is infecting river and marine mammals including otters and beluga whales (more info).
Provided your water authority can treat the waste, flushing is a good way to dispose of dog waste quickly and hygienically, so it's not sitting in the bin for days or weeks festering in the bag. The bags are also quite handy for indoor accidents if you have a puppy.
Available from Amazon here
You can put small amounts of dog poop into your compost bin - it's not advisable if you've got either a small bin or a large dog!
It's best not to use any bags if possible. Most biodegradable bags aren't compostable or can only be composted at industrial composting facilities. If you do use bags check they specifically say they are suitable for home composting.
Currently there are two certification bodies which offer specific “home compostability” certification programmes: Din Certco and Vinçotte. Look for the logos and check they say 'Home composting'
*SP premium poop bags, and
are all certified for composting at home.
When composting pet waste you need to be very strict about hygiene. The composting bin must be layered correctly and filled regularly to keep the temperature high - vital to kill the pathogens in dog waste.
Never use compost containing dog waste on or near food crops. If you are composting your dog's waste be sure to use a worming treatment regularly to reduce the risk of infection.
Insulated hot composters such as the Hotbin, which are made to work at high temperatures, can be used for composting pet waste. Small amounts of pet waste can also be added into a Green Cone. See more about the Hotbin and Green Cone in our post on Food Waste Digesters.
Pet poop wormeries are basically exactly the same as normal wormeries used for kitchen waste and work in exactly the same way. You don't need to buy a special 'pet poo' wormery.
The worms must be fed exclusively on pet waste as they won't tolerate a mixed diet, though you will need to mix about half and half with shredded paper and torn up corrugated cardboard to keep the waste aerated and stop it from compacting.
Don't use a wormery just after your dog has been treated for worms or you might kill all your little composters! Again, the compost and liquid fertiliser produced should not be used on or near food crops.
In the UK, Wormcity produce a range of stacking wormeries suitable for composting pet poo. These are kept in a shed or garage, so the worms remain active all year round. See them on Amazon UK *here.
See our posts on Worm Composting for lots more information.
Dog waste can be treated alone or added to food scraps in a bokashi system. This is a simple 2-stage process which firstly ferments the waste. The treated waste is then buried in the ground or added to a compost bin, where it breaks down very quickly.
Dog loos are generally sunk into the ground in a large hole with stones or gravel beneath to ensure good drainage. Water and a bio-activator, such as *Doggie Dooley Waste Terminator are added weekly to help break down the waste naturally.
If you are going to be digging a large hole, you might want to think about using a DIY system instead, as described below. You won't get a fancy lid, but it will be cheaper and less trouble to install, and will use less water. It might work better too, using natural bacteria and soil creatures to break down the waste.
DIY dog waste digesters
It's very easy to build your own dog waste disposal system if you have a garden with free-draining soil.
Dig a large hole, say 50cm x 50cm x 1 metre deep or more, depending on how many dogs you have. There's no set formula for the size of hole as it will vary with soil type, weather, dog's diet etc. If it fills up completely in less than a couple of years then it probably wasn't big enough.
Put some gravel or a layer of small stones in the bottom to help drainage. The hole must have a cover of some sort to keep rain, children and small creatures out.
The dog waste is simply put in the hole and watered - the waste should be kept damp but not sodden.
A layer of corrugated cardboard torn up into leaf size pieces is good now and then to keep the waste aerated if you are putting in a lot. A little sawdust, soil, leaves, grass clippings or compost sprinkled on top will help prevent smells and keep flies away. Don't use any plastic poop bags in this system.
The waste breaks down into the soil leaving very little residue. When the hole eventually becomes full just dig another hole, using the soil to cap off the previous hole.
For a working example of this very simple system see Sharon's Dog Waste Disposal Unit on YouTube.
Also, have a look at Mr Hardware's 'Puppy Poophole' in the video below for another variation.
The video here from City Farmer shows how to make a similar system by adapting an old plastic dustbin. This is better if your soil is soft as it supports the sides. Choose a bin with a good sturdy lid which is easy to remove but won't blow away in high wind.
Begin by drilling lots of 1/4" holes in the sides of the bin, 3 to 6 inches apart, starting from about 12 inches down from the top, then cut out the base. Don't drill any holes in the lid.
Dig a hole slightly deeper than the bin, and fill the bottom of the hole with a layer of rocks and gravel.
Sit the bin into the hole with the top just a little above soil level. All the holes you drilled should be below soil level to stop any smells from escaping. Back-fill the hole with the lid on the bin to stop the shape deforming.
Use exactly as described above, mixing the waste with a little sawdust and keeping moist, with some bio-activator now and then if needed. You can add composting worms instead of sawdust if you prefer - don't use any activator.
It will take a few weeks before the system is fully working, then all the waste should slowly biodegrade by natural processes and break down into the surrounding soil.
The bin will very gradually fill up over time. When it's full, if you used a straight sided bin it should ease out of the hole, leaving the composted waste behind. Cover it over with some soil and leave it there. Re-use the bin in a new hole.
There is very little to go wrong in this system. However, if it should fail for some reason - maybe it wasn't big enough for the amount of waste - cap it off with a mound of soil and leave it to sort itself out.
EcoSuperior have produced the useful video guide below, plus a useful fact sheet on how to make a pet waste digester which you can download here.
We hope this gives you some usable ideas for eco-friendly methods of dog waste disposal at home. Please let us know how you get on, or share any tips you have that people might find helpful.
*A great gift for dog lovers - a really cool waterproof and odour-proof washable bag for carrying your bagged waste until you can find a bin.
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