Sorting Through Our Garbage: TC’s First Waste Audit

It is a common sight in Grace Dodge dining hall. A well-meaning person has finished eating and now stands bewildered by the waste receptacles, wondering where to place the items he has just finished using. Is the pizza box recycling or compost? Can the salad container be recycled even if it still has some salad in it? What about napkins? Where do they go? Despite the signage above the bins, it is still difficult to get it right all the time, especially when in a rush to get to class. Many times, everything ends up in the landfill bin.

As Go Green Senator (AY 2016/2017), I was curious about how accurate people were being in their disposal. One critical factor in recycling and compost is that placing incorrect items into these bins can result in contamination of the entire load. Even one item out of place can mean that an entire bag of recyclables ends up in the landfill. We conducted a waste audit this spring to figure out what the community was doing well and what needed improvement. Our initial hypothesis was that the most often misplaced item was the compostable takeout containers. Through casual observation, it was apparent that many of these were ending up in either landfill or recycling. If covered with food, these containers would contaminate the recycling, so it was important to understand what was happening with them.

During Earth Week 2017, a friend, Gary Weiser, and I dove right in to the waste receptacles, wearing appropriate protection, of course. We chose one bag from the area labeled trash, one bag from recycling and one bag from compost. Our objective was to determine how well TC students were separating waste into the correct receptacles. We dumped out one bag at a time and separated the contents into what should actually go into landfill, recycling and compost. We then weighed each pile to calculate the percentage of each bag that was correctly and incorrectly disposed of. We also calculated the overall weight of edible food within each bag to give us a sense of how much excess food was being thrown out. The pie charts below illustrate the percentage of each bag that contained each type of waste. Overall, our results were quite encouraging, in that the compost and recycling bags contained mostly compost and recycling respectively. The trash receptacle, however, showed room for improvement, as more than 50% of the weight in that bag was made up of items that could have been recycled or composted.

The key takeaway from the audit was that people are actual doing fairly well at not contaminating the compost and recycling containers. When in doubt, people are throwing things into landfill rather than guessing. Although this means that much of the trash going to landfill could have been composted or recycled, this is a better situation than finding the other bins contaminated. The next step is to raise awareness about what can be recycled and what can be composted to continue to reduce what is going into landfill improperly. As predicted, the primary items that were misplaced were the compostable food containers. However, with the new Ozzi system started this fall, we will be able to reduce the number of these containers being used in the first place. Beyond that, better signage and continued discussion and education within our community will help make our waste disposal even better in the future.

Interested in learning more about recycling and composting? Below are some additional resources.

Information from Action Environmental Services (the service that TC uses for waste collection, recycling and composting):

Recycling - http://actionenvironmentalgroup.com/action-sustainability/recycling

Composting - http://actionenvironmentalgroup.com/action-sustainability/composting

Information from NYC Department of Sanitation (not used by TC, but probably used if you live off campus):

Recycling - http://www1.nyc.gov/assets/dsny/zerowaste/residents/what-to-recycle-for-residents.shtml

Composting - http://www1.nyc.gov/assets/dsny/zerowaste/residents/food-scraps-and-yard-waste.shtml

Results of TC Waste Audit