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 impact 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 - data is contradictory! Based on the math of dog & cat waste production = 9 tons* contradicts percentage reported by two recent Canadian waste audits**.
Municipal Solid Waste
Materials Landfilled (in % of total MSW % recycled % combusted with
(millions of tons) energy recovery
Food 35.28 21.5 Composting 21.85
Plastics 26.97 12.20 4.47 16.27
Paper/ 17.22 23.05 66.54 12.16
Metals 13.93 8.76 12.62 8.54
Wood 12.15 6.10 4.49 8.22
Dog & cat 12?* 12?*
Textiles 11.3 5.80 Rubber + 9.32
Yard 10.53 12.11 52.35 7.44
Glass 7.55 4.19 4.43 4.75
Rubber & 4.99 3.13 Rubber + 7.24
leather leather +
Misc. 3.27 1.39 0 2.32
Other 2.93 1.56 1.40 1.91
* 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 (Nova Scotia) 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.
This data projection shows that pet waste is under the radar. 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.