Audit Uncovers Waste Composition of MIT Campus

Friday, July 22, 2016


Kim Meersma | MIT Office of Sustainability Fellow

July 22, 2016

On June 30, 20 students, staff, and community members – unafraid of venturing into the unknown – conducted a waste audit to better understand MIT’s campus waste streams. The audit was organized by Rachel Perlman, a PhD student in the School of Engineering studying waste and urban metabolism. She partnered with MIT’s Environmental Solutions Initiative and MIT Facilities to plan and carry out the event. 

“We were excited to work with Rachel because the waste audits give us an idea of how the community is disposing material,” said Ruth Davis, manager of the Recycling and Materials Management Office. “By actually seeing what people are throwing into the trash instead of recycling, we can focus our education and signage and try to effect behavior change." 

Participants donned Tyvek coveralls and gloves, and sorted 544 pounds of recycling and trash collected from MIT buildings 13, 16, 35, 37, 56, 66 and 76. These buildings, unlike previous waste audits of trash at the Student Center, represent waste from mostly academic buildings, taking a snap shot of what we throw away in our day-to-day work activities at MIT. The waste was sorted into 20 categories and then weighed. 


Chart of the 20 categories used to sort the waste for the audit

Results from the audit suggest that almost half of the materials found in the trash could have been recycled or composted. Additionally, about 5 percent of content from the recycling bin were materials that had been improperly thrown away.

Volunteers sort campus trash into 20 categories before weighing it

The Problem With Waste

So why were these campus volunteers digging through waste on a summer’s day? The goal of the audit was to better understand the composition of waste streams at MIT. Perlman is using the audit results as part of a materials flow analysis she is conducting for the MIT campus. Her research is done through the lens of urban metabolism, which is a way of looking at the material inputs and outputs of an urban system, and seeing how these materials flow through an urban area. With this knowledge, institutions can make more informed and advanced decisions about sustainable waste management.

Though many people don’t think about their waste after it leaves their hands, material consumption is a critical issue on MIT’s urban campus. When we dispose of waste, it takes up space in the landfill and releases toxins into the environment, so the more waste that can be diverted from landfills, the better. 

Through the lens of urban metabolism, Perlman explained a different way of thinking about waste “All of the waste we generate was once, not too long ago, something we considered valuable – even as ‘waste’ this material has economic or nutrient value. Making things from scratch usually requires more energy and money than re-purposing or recycling products.”

Not only do waste audits provide an opportunity to collect data, but they give people a chance to think about waste as valuable materials.


Styrofoam packing peanuts were found in the trash. Styrofoam is expensive to recycle and toxic to the planet. 

Waste Audit Results

Though MIT continues to implement waste reduction strategies, the results of the audit illustrate that there is still work to be done. Much of the trash collected could have been reused, recycled or composted, and diverted from the landfill. The trash bags sorted contained an average of 32 percent food waste and 27 percent recyclable material. The audit also showed that some trash was ending up in the recycling bins. The average contamination rate of the recycling bags sorted was roughly 5 percent. 

A small sample of the organic food waste that was found in the trash during the audit 

Food waste, which is organic and compostable, was a big component of the sorted trash. “To help with waste sorting, we just added new sets of bins to four areas on campus,” Davis said. “In addition, we are beginning to strategize ways to donate food rather than just throwing it into the organic waste stream.”

Beyond organic waste, MIT has several initiatives that it hopes to expand in the future. The “Choose to Reuse” program allows the community to donate and obtain reused items for free. Another program, “MIT Student Furniture Exchange,” reduces waste by selling used furniture and household goods. MIT also has student groups working on sustainable waste management including the MIT Waste Alliance, UA Sustain, and the Graduate Student Council Sustainability Subcommittee.

Building upon the success of this audit, another audit is planned for the fall. If you are interested in participating, you can email

Special thanks to MIT Facilities and the Environmental Solutions Initiative for their generous support of the audit.

For more information about reducing waste on campus click here