Yellowknife isn't selling compost this year. Here's how the city will use it at the dump instead

Apple cores, chicken bones and napkins that are sorted into Yellowknife's green cart program will ultimately end up in the same place as the garbage, it turns out.

Christopher Vaughn, the city's manager of sustainability and solid waste, told CBC News the organic materials collected through Yellowknife's centralized composting program are being used as landfill cover.

"We're actually required to cover … our active landfill, with anywhere from 15 to 45 centimetres of soil," he explained. "We don't have access to that, it's not as easy to procure that soil in the North. So, using the low-grade compost is another way to save costs." 

The material is also stockpiled strategically around the landfill site in case of a fire, said Vaughn.

"Best practice in landfill is not to use water necessarily for the fire suppression, so landfills tend to use soil," he said, explaining the organic waste will help suffocate potential fires.

Food scraps in landfill still bad

Diverting the compost to the dump in this way is not a bad thing and people should continue putting in the effort to compost, says the Compost Council of Canada.

Susan Antler, the executive director of the council, says it's a "great use" of the organic waste.

The difference between sending food scraps straight to the landfill, and composting it before it's used as a cover, she explained, is that it's already gone through the degradation process.

"Composting uses air and mixing and time and all kinds of microbes to convert the raw organics into a finished product. That doesn't happen in a landfill," she said.

"Organics are the number one source of emissions from landfill. They basically burp up methane, which is a very nasty greenhouse gas."

The City of Yellowknife collected 893 tonnes of organic waste last year. 

The composting process reduces the weight of the final material, referred to as black gold compost, and in the past, the city has sold to it to residents for gardening.

On Thursday however, the city announced it would not hold a compost sale this summer. 

Local problem, local solution

The decision not to sell compost was made after receiving the results from an accredited lab in the South that tested samples of the city's compost, said Vaughn.

"There's certain criteria that needs to be met in order for our compost to be seen as non-restricted, and for it to be used for public distribution," he said. "Some of those things deal with trace elements, like heavy metals, some of those criteria deal with sharp material in the compost." 

It's making sure you put the right compost to the right use- Susan Antler, Compost Council of Canada

In its statement, the city also said "producing the highest quality compost necessary for use in gardens is a resource-intensive process."

Vaughn described using low-grade compost at the landfill site as a local solution to a local problem. 

"According to the regulations and best practices, we need to have something to cover [the landfill]," Vaughn said. 

"Here, we have an opportunity: as opposed to getting soil from elsewhere we can use something internally, that we collect from our residents."

What goes in matters

Antler, meanwhile, tries to avoid saying there is good compost and bad compost. 

"It's making sure you put the right compost to the right use," she explained.

"I think it's good news that Yellowknife is testing their product. They're doing what they're supposed to do; they're directing the use of the end product in the right way, based on quality."

The end product depends on what people are throwing in their green carts, said Antler. 

"There's nothing the compost facility can do, they can't wave a magic wand, they have to manage the products that are coming into the facility," Antler said.

"That's why it's important for people not to put plastics or anything that's not organic into their bins. Because it doesn't magically go away." 

Antler encouraged people to continue using their green cart to reduce methane emissions, to reduce the amount of waste that is being sent to landfill and to allow the city to improve its program.