Town explores organic waste to energy options

town to “evaluate its options for recovering energy and other resources from organic waste.”

At the sustainable planning and development committee meeting on April 16, the Town of Lake Cowichan mayor and council were given a chance to ask questions and go over a report presented by Stephen Salter of Farallon Consultants Limited. The report looks at the options available to the town to “evaluate its options for recovering energy and other resources from organic waste.”

What this means, in a nut shell, is that the town is interested in managing its own waste resources, minimizing the costs of management, and maximizing the value of recovered resources. There are several ways in which organic waste recovery and management could meet these ends: looking at providing heat to municipal and district buildings such as Cowichan Lake Education Centre, Palsson Elementary, and the town office; creating sources of revenue through additional sources of organic waste beyond town boundaries; and deciding whether to internally manage collection and production, or contract these services out.

Salter presented Mayor Forrest and council members with four options. The first looks at “Anaerobic digestion of wet organic waste.” This would mean building a facility capable of composting wet organic waste into methane and carbon dioxide which could then be used as an energy resource, or biogas. This biogas could be burned for heat, cogeneration of heat and electricity, or be upgraded to biomethane which could be sold to a gas utility to replace fuel in vehicles. The report looks at several possible locations including CLEC, the current Public Works yard, and at the wastewater treatment lagoons.

The second option looks at the aerobic composting of wet organic waste, which is simpler than the anaerobic option in that it would not involve the energy recovery part of the process. The wet biowaste would have to be mixed equally with wood waste, biosolids, and organic solid waste. The finished compost would then be stored on site and sold in bulk.

The third option looks at offsetting municipal energy costs through a biomass boiler. “Since the Cowichan Valley School District plans to add a package biomass boiler to the high school, modelling was based on the option of increasing the size of this boiler to serve both the school and the neighbouring area,” says Salter.

The fourth option looks at placing a micro-hydro turbine below the town’s sewage lagoons, just above where they dump into the Cowichan River.

Salter did point out several obstacles or challenges with all of these options.

“In none of the cases could I make the whole thing pay for itself,” says Salter. “In other words, if we were to go ahead and do it today, it would actually cost us money year by year, even when we take into account lower tipping fees for the CVRD.”

But his recommendations do suggest that building an anaerobic digester and collecting biowaste from the town as well as other municipalities and combining this with wet organic waste from the town’s sewage lagoons could create energy options and “defer part of the planned $5 million expansion to its wastewater treatment system.”

He says he looked at this from two points of view. Economically it would bring in enterprise and jobs, and it would be better for the environment. “On the other hand, something that’s a little better [. . .] would be to actually have that facility closer to Duncan,” says Salter. Reasons being that trucking distances would be less, waste materials could be sourced from local farms, and the locality of natural gas distribution lines would make it so that the production of biogas could be sold.

“And if you look at solid waste management plan within the district there is a long-range view of a remote composting facility not only to deal with food waste and organics, but also sludge from sewage,” says Coun. Tim McGonigle. “It is a long-term goal. I’m not sure this is the answer, or one that the district would be inclusive of, but worth investigating for sure.”

In terms of biomass alone, Salter says that the relatively light energy loads of the town’s buildings make it economically non-viable. “Biomass (woodwaste) is not expensive, and it’s abundant here,” says Salter. “[But] in order to make biomass work for energy, it would be a matter of grouping buildings together to try and have a system that would be big enough to serve several buildings.”

The best option economically, according to Salter, is to include in tender documents the requirement to install small biomass boilers when new buildings are constructed as opposed to a larger district initiative. He pointed to the fact that the town is planning to build a new municipal hall, and to the construction of the new library.

“So it would be good to look at it opportunity by opportunity,” says Salter.

“One of the things we learned in Sooke at the ICC is that there is an overabundance of sawdust in the island coastal forest industry, so that may be an avenue to investigate,” offered Coun. Tim McGonigle.

Mayor Forrest and council still have to decide if any of these options make sense to move forward on. They will also have to decide whether or not they will keep the operation of any biowaste collection and energy production “in house” or to tender the work to a private contractor.

Copies of Salter’s report are available upon request at the town office: 250-749-6681.