Middlebury composts almost 400 tons of food waste per year. In addition to collecting pre and post consumer waste from the college dining halls, compost is also collected from over 85 compost bins located in dorms and offices throughout campus.
Here’s a quick overview of our composting process!
Middlebury uses 22 gallon Rubbermaid containers with dollies with in the kitchens. These are small enough to fit through the dishwasher to maintain sanitary conditions in the kitchen. These containers are then dumped into larger 60 gallon totes. We modify the totes to be used with our specifically designed hook-lift truck.
Waste Management staff perform daily pick ups of compost in a specifically designed hook-lift truck. Collection typically takes 1-2 hours per day depending on weather conditions and quantity at each stop. The truck is then parked at our Recycling Center, moving any nuisance smells to the edge of campus. This box holds 2-3 days of food waste.
Pre-Consumer Food Waste: Middlebury’s dining staff deserves a ton of credit when it comes to diverting prep waste. We see very little contamination in the compost. They have built composting into their daily activities and it shows.
Post-Consumer Food Waste: Middlebury is successful at composting nearly all of the post consumer food waste from the dining halls as students deposit their plates, food and all to the dish room. Dish room staff then scrapes the leftovers (including meat), napkins and tea bags into a pulper.
Most of Middlebury’s kitchens are designed with composting in mind. This has made compost collections more efficient while eliminating odor. We use a large 40-yard enclosed roll-off to store food waste, which reduces the number of times mixing is required from two times per week down to once every 3-4 weeks.
We mix our food waste (1 part) with woodchips (3 parts) and horse manure (1 part). The horse manure comes from the UVM Morgan Horse Farm in Weybridge for the purpose of composting., and the chips come from our campus landscape debris .
Mixing and Turning
Our 344 HD John Deere loader works wonderfully to mix the ingredients and create windrows. These windrows are then turned on a routine basis to ensure good temperature, moisture and consistency throughout the windrow. This process is known as a Turned Windrow System.
Temperatures of active piles sore above 130 degrees killing weed seeds and harmful bacteria. Once the piles have fully “cooked” and the temperatures have reduced to near ambient level, piles are moved to a secondary pile awaiting screening. This can be tricky in the winter when freezing temperatures slows the “cooking” process. Piles then spend more time on the pad until the composting process is complete.
Once a year, Middlebury contracts with a local commercial composter who hauls a large compost screen to our site. The preceding year’s worth of compost is then screened and piled.
Maturing and Use
Once screened, the compost is then stored until the following spring. By allowing the compost to age for this additional time, we are ensuring a high quality, nutrient rich, product which can then be used at our Organic garden, on our athletic fields and throughout campus wide landscaping projects.
The material too large to fit through the screen is allowed to decompose for an additional year and is then rescreened in an effort to capture as much “black gold” as possible. As an alternative to land filling this material, Middlebury staff pick contaminants from the tailings and then build earthen berms around the cement pad to aid in litter control and aesthetics.