This tub’s for you: Selkirk initiates composting program

by Keith Powell — March 23, 2011

First-year Integrated Environmental Technology student and Compost Attendant, Sonja Seher, is currently being trained on the use of the Earth Tub at Selkirk College. — Carrie Voysey photo

Selkirk College has started a composting program at its Castlegar campus with the installation of a new Earth Tub.

According to the 2009 State of the Environment Report, produced by School of Renewable Resources Chair Derek Marcoux, up to 2.9 tonnes of waste (generated yearly) at the college is compost which could potentially be diverted from landfills. The Earth Tub, that is as big as a hot tub, will play a main role in the reduction of waste and is part of a pilot compost recycling program for the campus—one that the college hopes to replicate at its Nelson campuses.

The Earth Tub is approximately 1.7 metres high and 2.3 metres wide. It is designed specifically for on-site composting of food wastes and features power mixing, compost aeration and biofiltration of all process air.

Organic vegetable material food scraps are loaded through the large hatchway in the cover. Periodically, dry materials such as wood sawdust, shredded paper or shavings can be added to insure that porosity and moisture levels are ideal for composting.

Heat generated in the Earth Tub promotes rapid biological breakdown of the food scraps and other materials. For example, if 45 kilograms of waste food is mixed in the tub, it will produce a little more than 13 kilograms of compost within three or four weeks. Assuming, of course, the ideal mix of organic and bulking materials is obtained.

“In order for the Earth Tub to work properly, we have to keep an eye on what goes in it,” said Selkirk College director of maintenance and facilities, Ron Zaitsoff. “We’ve hired a student to weigh the materials and to watch over and record the composting process.”

First-year Integrated Environmental Planning and Technology student, Sonja Seher, has been hired to load the organic material into the Earth Tub, to mix it at least two times per week and monitor the project. Sonja will work in conjunction with the Kootenay Society for Community Living (KSCL) who will be assisting with daily compost collection. KSCL looks after the recycling program presently in place at Castlegar campus for paper, bottles and other recyclables.

For more information on the Earth Tub or click here or call 250-365-1444 for information on the composting program at Selkirk College.