Twice in the fall and twice in the spring, Edmonton residents with carts can set out as much yard waste as they want on yard waste collection days.
It is processed separately from food scraps and transformed into high-quality compost that is available to all Edmontonians, free of charge.
Here’s a look behind the scenes.
Pre-processing
The yard waste, collected in clear plastic or double-ply paper bags, is trucked
to the Edmonton Waste Management Centre and dropped off at the Integrated Processing Transfer Facility.
At left in the pic above, a track hoe operator is picking up the yard waste bags and transferring them to the bag breaker (the red machine) where they are ripped open.
Next, the yard waste and broken bags go down a conveyor belt to the front sort room, where staff pull any unneeded materials, such as bags or other large items, off the conveyor.
The material then goes into a trommel. This machine sorts the leaves, twigs and branches, pushing them through tiny holes in a circular motion.
Anything larger than the size of the holes in the trommel (approximately 7.5 cm – 12.5 cm) will not make it to the next step. The extra is sent back for additional sorting.
The disc screens then sort the remaining material. The yard waste left over is transferred to the Compost Cure Site.
Processing
At the site, the pre-processed compost is placed in piles in long rows. The core of these rows of compost is where the magic happens. Microbes in the compost pile combine and heat—up to 80 degrees Celsius—is generated.
The heat kills harmful bacteria and keeps useful bacteria suitable for gardening, landscaping and farming.
Periodically, the compost is turned by a mass bed turner (above). This brings oxygen back into the piles, which helps produce high quality compost with microbes that are beneficial to plants.
The compost is also watered periodically.
The result
When the compost is ready, it’s turned one last time using the trommel screener (above) and placed into its final piles. The result: clean, high-quality compost suitable for any garden.
Not only does this compost provide great nutrients to the soil, but its microbes help protect plants from disease.
Residents can pick up the compost for free at the Ambleside and Kennedale Eco Stations until October 15, 2021. Your garden will thank you.
The process of composting yard waste takes between 6 to 9 months. The material being composted this fall will be ready as compost for residents in 2022.
Find your yard waste collection days
To help the City continue to make high quality compost, set out your yard waste on yard waste collection days. Find your collection dates and plan your fall yard cleanup around them by visiting edmonton.ca/waste.
Editor’s Note: the pic at the top of the post shows a resident with a bundle of branches next to two paper yard waste bags set out for collection.