Compost Q&A

Q: I’ve heard you shouldn’t compost meat, bones, and dairy products. What’s the deal?

A: Larger composting facilities mix food scraps, including meat, bones, fats, oils, and dairy products, with carbon materials, hay, leaves, wood shavings, shredded paper, and manures into large piles, approximately 6-8 feet high and 12-14 feet wide at the base.  Because of their large size and proper recipe and moisture, these piles are excellent incubators for bacteria and fungi that actively break down the meat and dairy through a process known as aerobic digestion.  This breakdown results in temperatures of 140 degrees Fahrenheit or more year-round, which kills pathogens and even weed seeds, producing a healthy soil amendment. Compost pile temperatures above 131 degrees Fahrenheit for at least 3 days are required to destroy pathogens and weed seeds. In addition to destroying pathogens the heat produced in this process also acts as a major deterrent to interested animals.

It is possible to achieve hot composting conditions at home or at on-site composting operations. Typically compost piles need to be 1 cubic yard or larger to sustain heat, especially throughout the winter. You may also insulate a compost bin/pile to buffer the pile from losing heat. Using a thermometer probe to monitor compost pile temperatures can be a fun and rewarding experience that can help assure you’re achieving hot enough conditions to compost meat and other animal products.

Q: I’ve seen some packaging or other products that say “biodegradable” or “degradable” on them, can I put them into my compost pile/tote?

A: In general, the only products that are truly compostable are those approved by the Biodegradable Products Institute or BPI. Beware of front organizations claiming to certify other types of “degradable” products. Some chemical companies now make “bio-degradable” or “degradable” products, which are made of petroleum plastic that, over time, will break down into small pieces of plastic unnoticeable to the human eye.

Q: I’ve heard food scraps in the landfill produce methane gas. Do food scraps in compost piles release methane?

A: Methane is produced under anaerobic conditions (without air or oxygen).  Food scraps and other organic matter contained in plastic bags in sealed landfills do not have access to air, which in turn promotes the development of anaerobic bacteria (bacteria that thrive in environments lacking in oxygen), which release methane as they digest the food scraps.  Properly managed compost piles are turned, or aerated, maintaining proper oxygen levels.  This oxygen promotes aerobic (with air) microbial populations, which do not release methane gas when they breakdown and eat food scraps and other organic matter.  Studies have shown that properly managed compost piles release negligible amounts of methane.

This resource uses or is adapted from content originally developed by the Highfields Center for Composting in Hardwick VT. 

Q: Can I Compost kitty litter?

A: Certain brands of kitty litter lend it to more easily be composted. “The best choices for compostable cat litters are those made from natural, living sources…. Another good option for an earth-friendly and compostable cat-litter is a commercially produced litter made from pine or cedar.”
Ultimately, it’s up to your level of comfort on how much of your kitty waste you compost, what process you use to compost it, and how you use the finished compost. Here are some websites with different perspectives while support keeping the used litter out of the landfill:

Can I Flush Cat Poop and Scatter the Litter?