Surge in composting has Greater Sudbury looking for new ways to process organic waste
A move to extend the life of Greater Sudbury's landfill has worked so well, it has created new challenges for city staff.
In recent years, Sudbury has gradually reduced garbage collection from two bags a week to two bags every second week. The goal was to divert garbage away from the landfill, extending the life of the city dump.
But the surge in local composting has created a new problem: where to compost almost double the amount of organic waste residents are now discarding every week.
A report headed to the city's operation committee Sept. 20 says the amount of organic waste collected each year has risen from 2,095 tonnes a year in 2015 to 3,957 tonnes in 2020.
That material – separated into food waste and leaf and yard waste – is composted on the grounds of the Greater Sudbury Landfill. However, that area will eventually be needed to hold garbage. And with the growing amount of compost, a solution will be needed soon.
Under the current methods, it takes between six to eight months to compost the material, "but it is a cost-efficient method of managing the material," says a staff report on the issue.
"The organic processing facility is situated on a temporary area within the waste disposal footprint of the Sudbury Landfill, which will eventually need to be moved in order to fill the area with garbage."
With plans in place to expand the green cart composting program into other areas of the city, a long-term solution is needed, the report said.
Short term, a temporary area is being prepared for composting at the landfill. That also comes with challenges, the report said.
"Regardless of its location within the waste disposal footprint, this system poses operational challenges such as naturally occurring settlement of the pad area, pooling of water, and leachate seepage that require ongoing maintenance," the report said.
"In addition, during the relocation process, significant costs are incurred for construction of new pad and pen areas."
A partnership with Vale has eased the problems. Vale is taking semi-process leaf and yard waste and mixing it with other material and placing it in tailings areas to reclaim the soil.
"To date, the pilot project is considered a great success and Vale has expressed interest in expanding the pilot to include food and organic waste material," the report said.
"Staff are working with Vale to consider the addition of food and organic waste to the pilot project. If implemented, semi-processed food and organic waste could be shipped to Vale’s facility where it would be mixed with other compostable materials and then finally used in soil remediation activities on tailing lands."
Long-term, switching to what's called "anaerobic composting" would produce methane gas that could be captured and used to generate energy.
"After digestion, the remaining material can be further processed aerobically to produce compost," the report said.
Read the full report here.