George Mason University

01/23/2025 | News release | Distributed by Public on 01/23/2025 17:26

Breaking down the composting process

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Cindy Smith, a professor in the Department of Environmental Science and Policy, took her EVPP 302 Biomes and Human Dimensions students to a composting facility last fall to give them a front-row seat for food and yard waste recycling.

Photo by Cindy Smith/College of Science

In the course, students examine human impacts on ecosystems. Because human activities often have a harmful effect on ecosystems, Smith also aims to show students positive, real-world examples of how humans can help mitigate these impacts.

"I want students to experience successful programs that are doing positive work, like keeping yard and food waste out of our landfills where the breakdown would produce methane, a powerful greenhouse gas," said Smith.

The field trip also offers insight into a career path for those interested in sustainability.

The Convertus composting facility, located in Manassas, Virginia, produces certified compost, mulch, and soil amendment products in bulk. The facility can process 80,000-100,000 tons of organic waste per year. This includes yard waste, tree branches, and food and restaurant waste.

A milk hauler dumps excess or expired milk products, which Convertus uses in the composting process. The students noted that it made the area smell like vanilla creamer. Photo by Cindy Smith/College of Science

During the field trip, students watched stages of the composting process, from the delivery of waste to the grinding, mixing, aerating, screening, and composting. They observed the different effects of various materials.

"The students were surprised to see a red tint in the leachate pond [during our visit], which resulted from red wine waste being processed," said Smith.

George Mason University sends compostable scraps from multiple sources to the Convertus facility. Food waste is collected from campus dining and retail locations and Bigbelly Solar Zero Waste Stations. Two pilot programs collect compost materials in the form of paper towels from restrooms at the Facilities complex at Fairfax, and food waste from Katherine Johnson Hall at the Science and Technology Campus.

"It's great to see all this organic waste getting recycled into an economically viable product, rather than buried in a landfill or sent to a waste water treatment plant," said Smith.