Calgary's green cart compost program officially starts on Tuesday, with loads of kitchen and yard waste arriving at a new $143-million facility.

"It will just become the new normal behaviour, that this is just what you do, like recycling," said Philippa Wagner, the green cart project lead for the city as she toured media through the immense building.

Calgary's compost will be sold to offset some of the costs of the program. It's estimated there is 85 million kilograms of waste that could be composted each year.

One of 18 composting rooms at the new facility, where waste will sit for 21 days, and be constantly monitored. (Monty Kruger/CBC)

About five per cent of the finished product will be given back to the city for distribution at community gardens and to citizens, free of charge, on select days.

Wagner said the city expects the program to divert about half of a household's waste from landfills based on the results of a pilot project.

The waste goes through a five-step process at the facility, which Wagner said is the biggest of its kind in Canada, leaving a high-grade product that can be used on anything from farms to gardens.

Screening and magnets

That process includes two screening steps that remove waste that hasn't fully composted or items that should not be in the compost, like bags. Magnets are used to remove any metal.

While it sits for 21 days in a composting room, the waste will be monitored for moisture levels, temperature and oxygen levels.

"That's the phase that reduces the pathogens and why we're able to accept things like pet waste and meat and non-vegetative food," said Wagner.

A front-end loader sits in the now-empty storage area of the new compost facility, where the finished product will sit until it's sold. (Monty Kruger/CBC)

From green cart pickup to finished product takes about 60 days.

Wagner said the city will work with residents to ensure they're only putting the proper materials in the new green carts and to not throw away compostable items like vegetables, meat and yard waste.

"We always strive to educate first," she said.

"Ultimately, we may choose to not collect black carts that contain the wrong material."

With new bylaws, the city could also institute fines if residents steadfastly refuse to compost.

"We know that residents want to participate, so we're not expecting to have too many difficulties."

The program will roll out in phases, starting with the southwest quadrant on Tuesday, followed by the northwest between July and August, the northeast between August and September and finally the southeast by the end of September.