
I spend a lot of my time talking to people about composting. It is a vital part of the University of Michigan’s strategy to reduce waste sent to landfill and ensure nutrients get cycled back to rebuild our soils. It supports healthy ecosystems and food growth. However, I think all this talk about composting can overshadow the actions we can all take to reduce and reuse. We should avoid creating waste, even compostable waste, whenever we can.
Refuse & Reduce
Food waste is responsible for 8% of all greenhouse gas emissions. Composting helps reduce those emissions and has other environmental benefits. However, the greatest majority of those emissions comes from the production of food, not its disposal. The best decision we can make is not to take food or dishware that we don’t need so it doesn’t end up as waste. When you are hosting events, try to get an accurate guest count to prevent excess food at the end of the event. And don’t forget to say “no thank you” to those plastic cutlery sets and condiment packets when you already have silverware and a bottle of ketchup at home.
At an institutional level, Michigan Dining has won awards for its sustainability efforts, including reducing food waste with software that helps prevent over-ordering and their “Just Ask” policy, which allows you to ask for those chicken fingers without the french fries if you don’t want them. Finally, don’t forget to use up what you already have. Last year, the Planet Blue Student Leaders made a guide about how to not waste food in your fridge which is a great place to start!
Reuse
When it comes to food, “reuse” often comes in two forms: leftovers and donations. (Check out the US EPA’s freshly updated Food Recovery Hierarchy.) If food is still edible, we should try to make sure it gets eaten! At a personal level—I remind myself of the embodied resources it took to make the leftovers already sitting in my fridge to motivate myself to eat them rather than letting them go to waste. Sure I could compost them tomorrow, but that would still be a waste of all those inputs when I can eat it today!
For events, reuse may come in the form of allowing your guests or others nearby to take home leftovers. In large food operations like our dining halls, safe leftovers can be donated to food banks such as Food Gatherers and the Maize and Blue Cupboard. The Food Recovery Network does great work on campus collecting and donating excess food from dining halls. Since 2012 the University of Michigan chapter of this group has recovered 55,000+ pounds of food, which is approximately the weight of three adult African Elephants! And as an important reminder—when it comes to leftovers and donations, don’t forget to follow food safety guidelines!
Food and food serviceware are intricately linked, so it’d be remiss not to talk of it here. Many people think having compostable serviceware is the answer, but I’d encourage everyone to use reusables when you are able. U-M researchers Shelie Miller and Christian Hitt have fascinating research when it comes to reusable items over disposables. When using reusables, it is important to remember only to invest in them when you will actually reuse them enough times to make up for their increased resource use in production. Say “no thanks” to that flimsy reusable water bottle the random bank is handing out, but yes to the sturdy steel block M coffee mug you’ll use every morning on your way out the door. Do bring your own reusable silverware when grabbing takeout, but maybe leave the breakable china plate at home. Do bring your own set of reusable dishes to use in your office for lunch. For staff, the U-M Office of Campus Sustainability has a great “ditch the disposables” challenge you can check out.
Rot
And now we get to composting. No matter how hard you try, you are likely to end up with some organic waste—from apple cores and chicken wing bones, to the time you forget your reusable mug and pick up a compostable cup at Java Blu. Those items listed in the previous sentence are compostable on campus. There are over 1,000 compost bins on campus, most in food service areas or break rooms. There are a growing number of publicly located bins which can be found on our campus sustainability map.
Why don’t we have compost bins everywhere? We don’t have compost bins everywhere on campus because we can’t risk having any contamination in the compost bins. After you place the waste in the compost bin, it isn’t sorted. It goes directly to our compost site partner, Spurt Industries. If items such as Starbucks cups (have a plastic lining), ketchup packets (always plastic), or sugar packets (have a plastic lining) get into the compost bin, they can cause harm to the environment and wildlife at the compost site. They can also break down into harmful microplastics or leave behind dangerous toxins such as PFAS as they decompose—which get into our waterways or soils where they are taken up by plants and cause health concerns. Contamination from non-compostable serviceware and other items being accidentally thrown in the compost bin is such a large issue that compost operators near (City of Ann Arbor’s compost site operator WeCare Denali) and far (State of Oregon) are moving away from accepting any compostable serviceware at all.
What can you do to help? Help us keep our compost clean!
- Always compost food waste. On campus, we can compost any food waste, including meats and dairy. Our compostable waste gets sent to a nearby industrial composting facility (sometimes called “commercial composting”), which uses the wind row composting process. The heat and microbial activity in these large piles break down all the organic matter and destroy any potential pathogens. The final compost product is ready within 180 days to go to farmers, gardeners, and landscapers.

- Ensure any food serviceware you compost is BPI Certified. BPI certification makes sure that compostable serviceware does not contain traditional plastics or toxins such as PFAS, which are found in traditional disposables. The certification also confirms the products will break down into helpful nutrients for the final compost product. Make sure to look for the BPI Certified symbol!
There are many “greenwashed” products out there which advertise as environmentally-friendly but are NOT compostable. Don’t trust serviceware which just says “made from plants,” “biodegradable,” “bio-blend,” “natural materials”—all of these are unregulated terms. Many of these products are made by blending organic materials with more traditional plastics or are manufactured with PFAS which would leave nasty elements behind in our compost product.
- Make your events zero waste. The Office of Campus Sustainability can support your on-campus events to be zero waste with technical advice, hands-on assistance, compost service, and compostable serviceware (for student events & limited staff events) if needed. To receive the free support, you’ll need to complete a short, zero waste events training. Learn more and request support here.