Top option identified for institutional composting in Nelson

An interim report on institutional composting in Nelson suggests an “in-vessel system” would be the best choice.

An interim report on institutional composting in Nelson suggests an “in-vessel system” would be the best choice.

Consultant Fiona Galbraith, who addressed city council Monday, said it would be the “most applicable option for on-site composting at various facilities within Nelson, given the minimal space requirements of the system and the capacity to handle relatively large organic volumes.”

Galbraith was hired in March to assess composting technologies.

While the Regional District of Central Kootenay is considering residential composting as part of its resource recovery plan, Galbraith looked at options for organizations and institutions that wouldn’t be included, including schools, multi-unit residential buildings, and the hospital.

She studied a variety of alternatives and concluded the in-vessel system — large, rotating drums that are manually or mechanically agitated — has the best chance of succeeding.

“There are many mid-sized, in-vessel systems on the market and research is currently being completed to compile information for each system on implementation factors such as cost, capacity, labour intensity, and types of food waste that can be processed,” she wrote.

Another option is a Bokashi system operated by a private business, which would pick up compost and process it using microbes in an anaerobic environment. (City hall and the fire hall have such systems in their lunch rooms.) However, Galbraith said the service is only in the conceptual stage, so her final report will focus on in-vessel systems.

As part of her research, Galbraith visited Selkirk College’s Castlegar campus, which bought an Earth Tub system in 2010. With the help of students and staff, all on-campus organic waste is processed and the end material used in the Mir Centre gardens.

“There are many lessons to be learned from this project, including the need for a champion to oversee the project and dedicated labour hours for custodians and a composing operator,” she said.

She still needs to identify potential pilot sites in Nelson, but suggested the college might be a good candidate.

Galbraith has also met with regional district staff to ensure her work complements theirs.

Her next steps include addressing concerns around odors, leachate, and pests, including bears. She noted Thompson Rivers University in Kamloops has an in-vessel system in the middle of its main lobby.

She also plans to outline options to use the material within the community. “It gets people more invested in the system when they’re putting organics in which then feeds their flower beds,” she said.

Outgoing city councillor Donna Macdonald, whose motion initiated the assessment, said on-site composting for local institutions makes economic as well as environmental sense.

“Right now these places are paying a commercial hauler to carry away their compost,” she said. “It can be pointed out to them and they can calculate the payback of doing something different. It’s not just about doing the right thing, but about saving money.”

Galbraith’s final report, including recommendations, is expected early next year.