If you eat at the dining halls, chances are you’ve encountered Waste N' Weigh—the one day each month when green bins appear in front of the dish carousels, and guests are asked to scrape their plates into them. But what’s the purpose? Waste N’ Weigh serves two key goals: First, it’s a way to educate guests on how Notre Dame is working to reduce food waste. It also raises awareness about the collective impact of plate waste in the dining halls.
How Is Food Waste Managed at the Dining Halls?
At the dining halls, we follow the EPA’s Food Waste Scale, which prioritizes preventing and diverting food waste using the most sustainable methods.
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Food Rescue & Upcycling – Every day, any overproduced food is evaluated to see if it can be donated to Cultivate or repurposed into a new dish.
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Animal Feed – Fruit and vegetable trimmings are donated to a local cattle farmer to help feed his herd.
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Tracking & Reduction – Any remaining food waste is recorded using Leanpath, a tracking tool that weighs, photographs, and categorizes waste by product, location, and reason.
Once everything has been processed, whatever can’t be saved is sent to Grind2Energy.
From Food Waste to Renewable Energy
Grind2Energy is an anaerobic digestion system used by our Dining Halls and the Center for Culinary Excellence to divert food waste from landfills. Here’s how it works:
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Food waste is ground using an industrial-scale garbage disposal. However, instead of being sent to a water treatment plant, the ground food is cooked and turned into a slurry.
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The slurry is then transported to Homestead Dairy Farm, where it’s combined with other food waste and manure into their larger anaerobic digesters.
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Inside their digesters, the same anaerobic process further breaks down the waste, producing methane—a greenhouse gas 28 times more powerful than CO₂ at trapping heat within our atmosphere.
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Instead of releasing this methane into the atmosphere, the digesters capture it and convert it into energy using two Cat® G3512A gensets, which power and heat the entire farm. Any excess energy is sold back to the grid.
But the process doesn’t stop there!
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The liquid byproduct is turned into fertilizer for the crops that feed the cows.
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The solid material becomes sterile cow bedding, which goes back into the digester after use; creating a closed-loop system.
Why It Matters
In landfills, organic waste undergoes anaerobic decomposition, just like in the digesters we use. However, instead of being captured and converted into energy, the methane produced in landfills either leached or are flared into the atmosphere. By diverting all food waste from landfills, Notre Dame’s dining halls and the Center for Culinary Excellence prevent methane emissions that would otherwise contribute to the 8% of global greenhouse gas emissions caused by food waste.
Our anaerobic digesters harness that methane to generate renewable energy, support sustainable farming, and create a more circular food system.
For more information about campus sustainability, check out: green.nd.edu.