Campus Composting Ramps Up with Earth Tub

If you buy a sandwich at Humboldt State, it’s likely to come with locally-sourced produce, maybe a roll from a local bakery, and tofu made right here in Arcata. But what happens when that sandwich is just a crust and some mustard stains? With the recent installation of a large-scale composter known as the Earth Tub, the beginnings and ends of that sandwich can now be managed locally, too.

The Earth Tub is the new center of composting on campus. The tub is located in the Facilities Management corporation yard and is managed by the Compost Squad, part of the campus’s Waste-Reduction & Resource Awareness Program, an Associated Students-funded initiative. A fully-enclosed composting vessel, the Earth Tub can handle as much as 100 pounds of food and soiled paper a day, which, in addition to other waste diversion efforts, works out to eight tons of food waste diverted from traditional waste streams every year by WRRAP’s student workers and staff from the Office of Sustainability.

The composting process begins with the student workers collecting from the five permanent compost bins, from 20 buckets located in various departments and at student run coffee tables, and from bins used for zero waste events.


During a walk through of the process, compost site operators Chris Johnson, a Fisheries Biology major, and Jonathan Wright, who’s earning a double major in Forestry and CRGS, begin by weighing the day’s collection. Johnson and Wright then load the waste in the tub, and mix the compost with a powered auger much like a home composter would rotate his or her compost to introduce oxygen to the mix. Halley Walsh, a political science major and the compost director, records the weight and the compost’s temperature readings, which hit a balmy 140 degrees on a crisp fall day. Before the Earth Tub, campus composting took place behind the soccer field. According to Walsh, temperatures from the old pile never topped 110 degrees, indicating the Earth Tub is indeed capable of producing usable humus much more efficiently than traditional composting methods. The fresh humus is used on campus landscaping projects and by the Campus Center for Appropriate Technology. Despite its massive capacity, the Earth Tub has virtually no odor, thanks to an air filtration system that also helps to oxygenate the compost.

The Earth Tub, which was financed in part by gifts to the Humboldt Loyalty, Parent & Family Fund, is just one aspect of the campus’s Food Waste Diversion Program. The program includes education and outreach components and works closely with HSU Dining to increase use of compostable to-go containers and strategizes new ways to minimize waste.

Major highlights of the program include the 2011 waste characterization report that identified nearly 45 percent of the campus’s solid waste as food or compostable paper. According to Morgan King, the campus’s sustainability coordinator, by 2012 HSU reduced its solid waste by nearly 25 percent due largely to the removal of compostable material from the solid waste stream. HSU now sends over 3.5 tons a week of food waste to an off campus commercial composting facility.

In the near future the Office of Sustainability and WRRAP have plans to update the waste characterization study and expand composting opportunities with table-top compost bins for departments and check-out compost bins for students in residence halls.

Composting and education are just two aspects of the campus’s commitment to reducing, reusing and recycling waste. Programs including Zero Waste Events, Take Back the Tap, which promotes the use of reusable drink containers, and the Reusable Office Supply Exchange are all examples of how WRRAP contributes to making HSU a more sustainable campus.

The Office of Sustainability and WRRAP also provide numerous volunteer and internship opportunities that are open to students of all majors.

For more information, visit WRRAP or the Office of Sustainability.