Composting project takes a bite out of campus food waste

At restaurants and cafeterias, consumers have grown accustomed to seeing a line of waste containers for recycling glass, plastic and paper items. Important as those bins are for reducing the burden on landfills, they overlook a major source of waste: the food left on diners’ plates.

Food accounts for about one-third of the trash Americans throw away, and most of it ends up in landfills. While food is generally more biodegradable than some of the other items in the trash can, it’s not environmentally harmless. Decomposing food produces methane, a greenhouse gas that is 22 times more effective at trapping heat than carbon dioxide.

In an effort to reduce those impacts, UW–Madison has launched a project to collect and compost food waste from campus eateries. Organized by We Conserve, a university-wide program that promotes environmental stewardship practices, the project aims to compost more than 400 tons of food waste annually when fully implemented.

“UW has been composting for years with other organic materials, but we’ve found that great synergy can exist by adding food. It can really improve the quality of the compost product,” says Faramarz Vakili, program director for We Conserve.

Composting reduces the environmental impact of food waste by speeding up decomposition, reducing the period of time that food can release methane. A well-maintained compost window shrinks food components to about half their original size, reducing the stress on already crowded landfills. It also produces economical organic material that can be added to soil and reduces the need for fertilizer treatments on lawns and gardens.

To collect food waste, We Conserve worked with the Wisconsin Union’s food services unit, which helped set up food-waste reservoirs at two locations. One is in the kitchens at Memorial Union, where food is prepared for all Union delis across campus. Twice a week, employees collect spoiled and unsold food that would normally wind up in garbage cans. The second reservoir, located at Grainger Hall’s Capital Cafe, serves as a collection point for post-consumer food. Food from both sites is taken to the West Madison Agricultural Research Station, a facility on Mineral Point Road run by the College of Agricultural and Life Sciences, for composting.

The project has presented some challenges, particularly in educating consumers about how to sort food for composting. “Not all foods belong in a compost heap, especially meat and dairy products. So it’s important that discarded food wastes are separated to keep out things that don’t decompose well,” says West Madison superintendent Thomas Wright, who oversees composting at the research facility. To help guide consumers, We Conserve constructed a food-collection station at the cafe that uses signs and pictures to designate the proper containers for different kinds of food. Vakili says the station has helped boost the number of people participating in the project, and he’s confident that diners will catch on and embrace food sorting in time.

“We want to put the idea of environmental stewardship on people’s radars,” says Vakili. “When a person is engaged in doing a good thing for the environment, then subconsciously they are interested in doing more. One thing leads to another.”

Meanwhile, the university hopes its successful composting experiment leads to an even bigger impact. Plans are to expand the project into residence hall dining facilities by the end of the year. Provisions have already been made to provide the dining halls with collection bins and equip the staff with biodegradable plates. If students embrace the idea, it could make a significant dent in reducing food waste on campus.

“Effective composting takes time and effort, and while we would love everyone on campus to create their own, that’s just not possible,” says Wright. “So this program is making it easy for them. All they have to do is give us their food, and we will do the work.”