Composting operations helps make campus beautiful

The Appalachian State University campus is known for its natural beauty. What helps make campus landscaping look so healthy? Part of it is the nutrient-rich mulch made from composted food scraps.

Appalachian's on-site food waste composting program—which takes vegetable scraps and other pre-consumer waste from Food Services and lets them decompose into soil instead of going to the landfill—is the first and largest in-house composting operation in the UNC system. The program was recently honored by the Carolina Recycling Association with the Outstanding Composting or Organics Program Award.

Appalachian's first composting facility opened in 1999, in response to a proposal by sustainable development students to implement food waste collection. A new compost facility opened in October 2011 and can handle up to 275 tons of materials, compared to about 100 tons with the university's former system.

The new operation is the result of successful collaborations between Food Services and ASU Recycles, the university's recycling program. The composting facility is permitted for pre- and post-consumer food waste from Food Services, but only pre-consumer waste is recycled into compost at this time. Wood chips and tree trimmings from campus maintenance also are composted.

Appalachian already was diverting about 40 percent of its waste before the new facility opened, according to Physical Plant Director Mike O'Connor, and "this will allow us to increase that number," he said. "It's going to really help us in our sustainability efforts."

"I think this is a good idea," said junior Ashleigh Miller, a graphic design major. "Why not use something that would normally just fill up a landfill? Plenty of people use compost as fertilizer, so why not the university?"

One of the students who helped get the program started in 1999 was Jennifer Maxwell, a 2001 graduate who now works as Appalachian's resource conservation manager. She accepted the Carolina Recycling Association's award on behalf of the university in March.

How composting works

Composting is a naturally occurring phenomenon, in which microorganisms break down materials when given the proper amounts of air, water, carbon in the form of wood chips and tree trimmings, and nitrogen in the form of food waste.

The process generates heat, which further breaks down the materials. All pathogens in the material are killed when Appalachian's compost reaches a sustained temperature of 131 degrees Fahrenheit for three days followed by 11 consecutive days of temperatures above 104 degrees Fahrenheit. Compost is ready to cure following this two-week period, and can be used as a soil amendment after a 45-day curing period.

Appalachian's composting facility has bins designed with under-floor piping of air and collection of moisture run-off, known as leachate, which can be reapplied as needed to facilitate the composting process.