In 2023, two successful experiments were conducted on opposite sides of the globe, utilising tumblers for the composting of dog waste. This approach is particularly suitable for individuals with limited yard space.

Here’s a fact sheet with step-by-step “how to” instructions and project outcomes.

When trying this with your own dogs, it’s important to know that each situation is different in terms of quantity of waste, available added materials, weather and climate. These projects are meant as guidelines. Keep experimenting to find the tumbling method that’s right for you!

View the webinar video on this topic here.

Committed dog park visitors are using compostable bags and separate bins to make the town’s new dog waste composting program a success. According to the Assistant Town Manager, dogs at Autrey Park have produced 500 lb. of waste, which Pet Scoop collected and delivered to EnviroWagg for processing into a safe soil amendment.

The Lafayette Parks, Recreation & Open Space Department, in collaboration with the Lafayette Waste Reduction Committee, is pleased to announce the launch of a pilot dog waste composting program at the Great Bark Dog Park. Dog waste can be challenging for communities to deal with, and most of it ends up in landfills where it contributes to emissions from methane, a potent greenhouse gas. Nationwide, pet dogs produce over 10 million tons of poop each year, and Lafayette wants to do what we can to minimize our contribution. More to bark about.

Toilets and sanitary sewage treatment provide humans with a workable solution to waste disposal. But there is no effective, broadly-implemented way to tackle the problem of pet waste. At this point, most pet lovers, shelters, kennels, breeders, municipalities, and pick-up services are left to their own devices.

Studies show that roughly 40% of all dog owners do not “stoop and scoop” and the ecosystem doesn’t gracefully embrace dog waste. If left intact, it can take more than a year to break down and can quickly turn any outdoor area into a site unfit for pets and humans.

In addition to the mess and smell, raw dog waste spoils grass and other landscaping. Dropped along trails, it kills native plants and encourages noxious weed infestation. Residual waste left at ground zero runs off into storm sewers and waterways.

Studies indicate that dogs are third or fourth on the list of contributors to bacteria in contaminated waters, increasing the potential for serious diseases, including cholera and dysentery. The EPA estimates that two days worth of dog waste from about 100 dogs can create enough pollution to close a bay and all the watersheds within 20 miles.

In addition to threats to humans, bacteria that feed on dog waste deplete oxygen, killing native aquatic life. The bacteria also feed algae blooms which block sunlight and suffocate fish. On fragile terrain such as hiking trails, dog waste contributes to the growth of invasive weeds that endanger native plants.

What doesn’t get measured doesn’t get done.

Calculating how much dog and cat waste is streamed to landfills in the U.S. alone is difficult to do and the amount increases each year. There are no comprehensive official statistics, but here is one attempt to quantify trashed pet waste based on available data.

According to the 2017-2018 American Pet Products Association’s National Pet Owners Survey, there are a total of 89.7 million dogs and 94.2 million cats in the U.S. The same survey indicates that pet ownership has consistently trended upward over more than two decades.

Dogs

The Environmental Protection Agency estimates that the typical dog generates three quarters of a pound of waste per day – or 274 pounds per year. Therefore 89.7 million dogs produce 67,275,000 pounds (33,637.5 tons) of waste per day or 24,555,375,000 pounds (12,277,687.5 tons) per year. Each year U.S. dogs produce enough waste to cover 109 football fields (including end zones) 10 feet deep.

How much is trashed? A total of 80.7%: Percent of the US population living within urban areas; that calculates to approximately 78,039,000 urban dogs. According to several surveys, roughly 60% of dog owners say that they pick up after their dogs (Pollution Prevention Fact Sheet: Animal Waste Collection, U.S. Storm Water Center https://www.stormwatercenter.net/Pollution_Prevention_Factsheets/AnimalWasteCollection.htm). Sixty percent of 78,039,000 dogs brings the number of urban dogs with owners who pick up their waste to 46,823,400. Those dogs produce 35,117,550 pounds (17,558.78 tons) of waste per day or 6,408,952.875 tons per year.

Cats

Cats poop less, but there are more of them and city cats’ waste is co-mingled with mostly clay litter. No organization has undertaken an official study of the amount of waste cats produce, but an informal measure reported by Rose Seemann in The Pet Poo Pocket Guide: How to Safely Compost and Recycle Pet Waste https://earthhero.com/products/sustainable-essentials/rose-seemann-the-pet-poo-pocket-guide/ indicates that an average cat leaves around .3 pounds of waste/litter per day to be trashed. Approximately 70% of the 94.2 million cats are kept indoors. These 65,940,000 indoor cats produce 19,782,000 pounds (9.891 tons) of waste day or 3,610,215 tons (300,000 dump truck loads) per year.

This does not include co-mingled plastic and bulk cat litter resulting from litter box dumps. Disposal of the litter itself presents challenges. According to Judd H. Alexander in 1993’s In Defense of Garbage, over 2 million tons of cat litter ends up in landfills each year more than 2 million tons of clay litter is disposed of each year in the United States. That was 1996, but we’ll use that conservative number in our stats.  So the sheer volume of used cat litter has a significant impact on landfills

Total pet waste to landfills

Six and a half million tons of dog waste plus 3.6 million tons of cat waste plus 2 million tons of disposed litter totals approximately 12 million tons of pet waste streamed to U.S. landfills each year.*

Pet waste compared to other U.S. waste

When reviewing the data for waste quantities below, keep in mind that anaerobic degradation of organics such as pet waste in landfills results in methane emissions that air quality.

• “Each ton of organic waste disposed of as landfill and broken down by anaerobic fermentation releases about one ton of carbon dioxide equivalents(CO2–e) of greenhouse gases, mostly in the form of methane”. 
• Municipal solid waste (MSW) landfills are the third-largest source of human-related methane emissions in the United States, accounting for approximately 15.1 percent of these emissions in 2018
• In “Strategies for Reducing Degradable Organic Wastes in Landfills the Wisconsin Department of Natural Resources states: “Current landfill designs and practices do not provide for degradation of landfilled organic wastes within a defined and reasonable timeframe. Un-degraded organic wastes can potentially cause future environmental or economic impacts if the landfill gas and leachate collection and containment systems (cap and/or liner) fail at some time in the future. Potential economic burdens and environmental risks associated with these undegraded wastes will be largely borne by future generations.”

Below: from U.S. Environmental Protection Agency: 2018 Facts and Figures about Materials, as posted March 2021

Printed in black: direct data from EPA 2018 Facts and Figures (disposal of traditionally quantified materials)
Printed in red: estimated pet waste in residential waste stream

Municipal Solid Waste

* Six and a half million tons of dog waste plus 3.6 million tons of cat waste plus two million tons of disposed litter totals approximately 12 million tons of pet waste streamed to U.S. landfills each year.

** “We have been doing a series of waste audits on residential garbage. We’ve done two so far and the third is slated to be done August/September of 2018. What we did find in both of those audits, consistently, is that 12 per cent of what is in the residential waste is pet waste.” Susan Grimm, team leader, City of Airdrie (Alberta) Waste and Recycling Services 

** According to Kirk Symonds, team lead-education and program delivery with Halifax Regional Municipality Solid Waste Resources, pet waste represents eight to 12% of the weight of all residential waste headed to the landfill. That weight includes kitty litter, dog feces, feathers, and pet bedding.

Summary

This data projection shows that pet waste is under the radar for the EPA and other agencies regulating and setting policies for MSW. But the need for accurate data on the quantity and its relationship to other MSW is essential to developing standardized best practices for diverting pet waste from landfills.

When planning a pet waste recycling program, it’s important to find out the amount of pet waste that your project will be tackling. This data will be key to choosing options and applying for grants. Here are formulas for arriving at the numbers you’ll need. If your project includes dogs and cats,  simply add totals for both.

DOGS

– The average dog produces .75 lb. of waste per day.
– Sixty percent of urban dog waste is picked up and deposited in bins.

Medium scale project – 100-300 pets per day
– Determine the number of dog visitors or clients served per day.
– Multiply that number by .75 for daily weight of waste.
– Alternately, you can set up a dog-waste-only bin and weigh the bin daily or weekly. Subtract the weight of the empty bin.
– Simple multiplication will take you to anticipated monthly or annual weight.

Large-scale projects – more than 300 pets per day

If a large park or event, follow the directions above for a medium scale project.

Residential waste from towns, cities or other jurisdictions
– Determine the number of households (see recent census).
– To find out the number of dogs, multiply households by .53.
– Multiply the number of dogs by .75 and you’ll have the weight of dog waste produced within the community per day.
– Simple multiplication will take you to anticipated monthly or annual weight.

CATS

– The average cat produces .3 lb. of waste and litter waste per day.
This does not include cat litter resulting from litter box dumps, estimated at more than two million tons of clay litter each year.
– Alternately, you can set up a cat-waste-and litter-only bin and weigh the bin daily or weekly. Subtract the weight of the empty bin.
– Simple multiplication will take you to anticipated monthly or annual weight.

Medium scale project – 100-300 pets per day
– Determine the number of cat visits/clients served per day.
– Multiply that number by .3 for daily weight of waste.
– Alternately, you can set up a cat-waste-only bin and weigh the bin daily or weekly. Subtract the weight of the empty bin.
– Simple multiplication will take you to anticipated monthly or annual weight.

Large-scale projects – more than 300 pets per day
Residential waste from towns, cities or other jurisdictions
– Determine the number of households (see recent census)., determine the number of households (see recent census).
– To find out the number of cats, multiply households by .38.
The average cat owner has two cats, but 50% of cats are outdoor cats, so we’ll go with one cat per household.
– Multiply the number of cats by .3 and you’ll have the weight of cat waste produced within the community per day.
Simple multiplication will take you to anticipated monthly or annual weight.