This past month, one of our middle school teachers and I worked together to conduct a food waste audit. Susan, the middle school’s French teacher, is an unbelievable champion of waste diversion and environmental action, and volunteers her time every day to make sure that kids’ food waste and recyclables are properly sorted each lunch period year-round.
As my job is based at the middle school, its easy for me to help out on my breaks and Ive started assisting on occasion with overseeing the lunchtime process. We wanted the school to understand how much of a difference their efforts at diverting waste from the landfill really made.
We conducted a five-day audit of all food waste from 7th and 8th grade lunches. Food waste was weighed at the end of each lunch period, and totals for each grade as well as daily totals for all food waste was collected. We found that our school produced an average of about 37 lbs of food waste for composting per day.Multiplied by the number of lunches per school year (assuming 5 days per week x 35 instruction weeks), approximately 6500 lbs of food waste per year are being diverted from landfill by the food waste composting program.
We then used some simple estimates of the amount of greenhouse gases that are produced by food waste in a landfill versus that produced when food waste is composted, to come up with an estimate of about 4200 lbs of greenhouse gases that are not being emitted because of this program. Using an “equivalency tool” from EPA, a couple of other ways to look at this number is as equivalent to 1.5 acres of forest sequestering carbon over the course of a year; or saving the amount of greenhouse gas emissions from driving a car 4,500 miles.
We also noted during our audit that many students are using reusable or compostable (brown paper) lunch bags, and that students are doing a great job learning to appropriately sort their lunch to divert food and recyclable waste from going in the trash. At the same time, there’s room for improvement- many of the items that are both available at school lunches and that kids bring from home are not recyclable, and in particular, ziploc bags, chip bags, and clamshells stood out as plastic that piled up in the trash bin.
Susan and I will be continuing to work on this together to share our results with the school and community, as well as work to make changes at the district and school-level that hopefully will reduce our trash generation – and our contributions to climate change- even further.