With scales zeroed, Tyvek suits on, and hot coffee at the ready, Harvard Medical School conducted a waste survey or “audit” prior to December’s holiday break. The audit tracked how much trash could have been reused or diverted to recycling or compost. According to Rob Gogan of Harvard Recycling and Waste Services, it was the most comprehensive waste audit at Harvard’s Longwood Medical Campus.

Previously, Medical School students conducted a waste audit as part of a recycling education campaign, which was supported by OFS through a Student Sustainability Grant. That audit focused on HMS’s education buildings, while this audit gathered waste samples from administrative and research areas as well.

Additionally, a “perfect” bag was found. In his 26 years of auditing waste from Harvard, Rob Gogan says that he has, “never found a sample trash bag without any recyclables or compostables. At HMS, I found one!” Gogan has audited over 1,200 bags at 130 waste audits without funding such a bag. 

The process required collaboration from several offices including Harvard Recycling and Surplus, HMS Custodial, HMS Campus Services, HMS Parking, and the Office for Sustainability, in addition to volunteer waste-sorters from the Longwood community.

For three consecutive days, HMS’s Custodial Services collected waste bags from pre-selected locations across campus, representing a variety of space-types including kitchenettes, laboratory, office, and common-area. Sample bags were collected for multiple days in an effort to establish a rough average. In total, over 60 bags were collected from 20 locations. Each was tagged with the date and specific location, collected into hampers, and ultimately brought over to the chilly sorting area in the Warren Alpert “Quad” Parking Garage.

Due to various constraints, volunteers sorted roughly 40 of the bags and withheld from sorting most of the laboratory sample bags.

Each bag was individually sorted and weighed accordingly. The data was documented to determine the proportion of each bag that could have been diverted to alternative streams such as reuse, recycling, or compost.


  • Fully two thirds of the items could have been diverted, whereas one third – by weight – was legitimately trash.
  • 19% of the items could have been recycled.
  • If we eliminate the compostable materials, representing 40% of the total, then recyclable material increases to represent 31% of the total and actual waste represents 51%.

Most of the locations where samples were collected do not currently have compost bins available. HMS is in the process of rolling out new waste bins standards, updating signage, and expanding the compost collection areas in the hope of increasing the proportion of compostable material that is accurately diverted. With these changes, the 40 percent figure should drop over time.

It is important to acknowledge the steps that Harvard’s kitchens and dining facilities take to sort organic matter. They divert substantial amounts of “back-of-house” compostable material that is generated during meal-preparation. The efforts of the Longwood EcoOpportunity Team and the Office for Sustainability are aimed at improving, the “front-of-house” opportunities from folks who discard the remains of their lunches, snacks, and coffee grounds.


The waste audit numbers establish a helpful, if imperfect, baseline allowing the impact of changes to be tracked over time. Harvard’s Longwood Campus is in the process of making substantial improvements to the waste-program, including rolling out new waste-bin standards, an expansion of areas with compost bins, and updated signage that reflects best-practices.

For those who spent time sorting through the bags, we hopefully have a deeper understanding of the opportunity at our hands and respect for those who work throughout all upstream and downstream stages of waste. Finding unopened baby carrots and a large container of hummus may make one rethink what we discard.

The high proportion of compostable material reinforces the value of improving the availability of compost bins. Furthermore, that much of the compostable material was not food, but biodegradable plates, bio-plastic cups, and used napkins reveals that many people are already choosing to purchase alternative materials, but that systems are not always set up to benefit from these choices. A high proportion of non-food items can also create challenges during the digestion process for commercial compost facilities. They require a balance of rich organic material to accompany items like bio-plastics and paper-products in order to effectively break down all items.


The limitations of the study are helpful to understand for anyone considering conducting their own waste audit or for folks interested in the nuances of the process. The samples collected were strictly from trash bins; recycling, compost, hazardous waste, sharps, universal waste, or any other waste-stream categories were not included. This survey was limited to this category of the waste stream for both practicality and safety purposes. Results, therefore, only convey the proportion of trash that could have been reused, recycled, or composted. It does not reveal the proportion of waste that was accurately diverted from the trash, nor whether there was contamination in any other waste stream.

Furthermore, trash samples were not collected from a randomized selection of locations. As a result, data is not derived from a formally representative sample of the campus. The results were not strictly analyzed to counter for factors such as proximity to the holiday break, which may have skewed the proportion of reusable dishware that was found, among other items. Given the timing, results may not accurately reflect the average amount of waste generated at a given location over the course of the year. During holiday parties or other gathering occasions, there is a tendency to over-order. There can also be a rush to clean up quickly, often at the expense of accurate waste-diversion.