I walked into the South Quad dining hall with Keith Soster, director of Student Engagement for Michigan Dining, and was impressed by the upscale cuisine, stainless steel furniture and natural light. There are multiple stations for different types of food, with students talking, eating and studying at the tables around the area.
Behind the scenes of South Quad dining, food waste is being diverted from the landfill through composting. “The biggest goal for composting is waste diversion,” Soster said as we walked around the dish room. “When you’re talking about food facilities and the volume of food they produce, there’s quite a bit of volume of waste, so being able to get that in a place other than the waste stream can be a beautiful thing.”
Soster and I started our tour of the South Quad kitchen composting facilities. We watched as dining hall employees cut the stems of fruits and vegetables, and put them into pre-consumer composting bins. According to STARS, the Sustainability Tracking, Assessment and Rating System, pre-consumer composting includes all food waste and compostable paper and plant-based products being composted during preparation and cooking before being served to customers (e.g., produce, dairy, and meat trim loss and any other food products that cannot be eaten or salvaged).
“Everything we can’t utilize goes into pre-consumer composting,” Soster told me as we watched food scraps go into the blue bins marked for pre-consumer composting. “We worked with waste management to start pre-consumer composting and we’ve done that in all the residential units.”
We went to the back loading dock where there were many different containers used to separate materials — compost, trash, paper and plastic recycling and a container for Styrofoam. A room located off of the back dock houses a machine called ‘The Extractor,’ which has a number of tubes with water circulating through the food waste contained in it.
“This is called the extractor. It’s actually a pulper. [Students and dining hall employees] scrape the plates upstairs, and the food goes into this machine. It’s chopped up into a slurry and mixed with water. It’s rinsed two more times and ground up, and then water is extracted and goes back upstairs [to the dishroom],” Soster said. Food scraps are pushed into the extractor, and water from the extractor can be reused to clean dishes. This reused water is called “gray water,” named for its murky color. Gray water is gently used water that can increase the sustainability of a system and reduce the total amount of water use. In South Quad it’s used to rinse dishes before they are fully cleaned in the industrial dishwasher.
The next step in the process led us to a room with food scraps ready to be composted. Water removed from the food scraps increases the efficiency of transporting it to the composting site run by We Care Organics, where it is transformed through the composting decomposition process into nutrient-rich organic matter that can be applied to soil.
We went back upstairs to the dish room, where we watched a dining hall employee use the gray water from the extractor machine to rinse off dishes with food scraps. Most of the materials in the dining hall like napkins and coffee stirrers are compostable and go into something that looks like a trough that leads downstairs to the extractor.
Composting reduces the impact that we have on our environment. It returns organic resources to the soil, encourages healthy root structure and conserves landfill space. Composting is good for us and our environment, making it one of the most important things we can do to encourage sustainability.
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About the Author: Rebecca Lerner is a Planet Blue Ambassador and assists with efforts to promote sustainability. She is a U-M student studying English and Screen Arts and Culture and is working as a writer with the Graham Sustainability Institute.
Sustainability Series & Guide: This series is designed to demonstrate how the U-M community is working to fulfill campus sustainability goals in the areas of climate action, waste prevention, healthy environments, and community awareness.