Even on a day with a high of seven degrees Fahrenheit and a wind-chill as low as negative six, the compost pile between the Human Rights Center and the urban agriculture plot produces warmth and steam. The compost system has faced difficulties this term, but has resumed full operation as of Monday, Feb. 16.
The compost system processes both pre-consumer waste, which is put into the compost area in solid form, and post-consumer waste, which requires further processing.
Post-consumer waste from the Hard Knox Caf and the Gizmo is first processed in a macerator, which reduces its volume and grinds it into smaller pieces. Then, it is put through a dehydrator before being taken to the compost area.
“This processing neutralizes the oils so that the waste will degrade quickly and without horrible smells,” Sustainability Coordinator Froggi Van Riper said. “You wouldn’t put a piece of hamburger directly into your compost pile, but a macerated, dehydrated piece of hamburger, you can.”
Currently, the compost system processes an average of 310 pounds of waste a day, or more than 10 tons a term. This is best seen as the amount of organic waste diverted from landfills; the actual amount of material left over after composting is only a fraction of this.
“It loses a lot of its water weight during dehydration, and then loses some of its carbon during decomposition. Ultimately, the amount of compost produced is only a fraction, probably a seventieth of the original weight of the raw materials, but all of the phosphorus remains in the compost,” Van Riper said.
Recently, the composting system faced technical difficulties that temporarily compromised its ability to process organic waste.
“The macerator, which is essential to the process, got some sort of metal object in it and broke — it could have been an aluminum can, or maybe someone’s retainer,” Van Riper said.
Having the macerator serviced presented new unexpected problems.
“Unfortunately, because its such a unique piece of machinery — there are only two in Illinois — we had to wait four weeks as the replacement part was custom manufactured for us, during which the system had some trouble processing compost,” she said. “However, we decided to keep collecting compost in the Gizmo while the macerator wasn’t working, mostly so people wouldn’t get out of the habit of composting.”
While the macerator was broken, the volume of post-consumer organic waste that could fit directly into the dehumidifier was still processed. However, without first having its volume reduced in the macerator, a portion of the waste would not fit into the dehumidifier. This portion of organic waste was then put into a landfill.
The Office of Sustainability made the decision to continue collecting compost in the Gizmo even when the system was compromised in order to maintain the instructive aspect of the compost program.
“The Gizmo is what I’m most proud of, because it has a pedagogical aspect. You have the patrons having to sort their own waste into compostable and non-compostable,” Van Riper said.
Ultimately, this pedagogical aspect has been one of the central successes of the compost program.
“Froggi didn’t want to stop collecting compost in the Gizmo for too long because people would get out of the habit of composting,” Sustainability Chair Inez Pena said.
This cultural or pedagogical problem Ñ teaching people how to sort their waste — is a central one for the project of sustainable waste processing.
“When we started collecting compost in the Gizmo last term, a lot of students didn’t even know what compost was,” Pena said. “Now they are able to sort out their compost without having it explained to them.”