The City of Edmonton estimates that about 50 per cent of single-family residential waste may very well be composted, and yet, only about six to eight per cent is.
Most municipalities aim to capture about 80 per cent of their organic waste, environmental engineer Daryl McCartney said.
Once they start a compost program, they’ll typically capture about 30-50 per cent but with time, practice and public education, municipalities can push that rate as much as 80 per cent, the University of Alberta professor explained.
“Less education, the lower the capture rate and better contamination as well,” he said.
Seattle is the gold standard, in keeping with McCartney.
The 2018 Seattle Public Utilities Waste Prevention and Recycling Report states in that 12 months, town had an overall recycle rate of 56.5 per cent. Out of 796,822 tons of waste, 450,500 tons were diverted from the landfill and 346,322 tons were disposed of. That very same 12 months, Seattle’s residential recycling rate for every kind was 62.8 per cent. The town’s 2022 goal is to succeed in 75 per cent.
During its most successful years, Edmonton was capable of divert about 60 per cent of its waste from the landfill too, McCartney said, but its contamination rate was higher — meaning there was still garbage mixed with the organics.
Green cart, black cart, blue bag
Seattle, which is one in every of the few cities to share waste data publicly, has residents separate their organic waste from their other garbage — and so they do quite a superb job. Seattle has an incredibly low contamination rate for its organic waste: two to a few per cent in peak summer months and 4 to 5 per cent the remainder of the 12 months.
Calgary launched its green cart composting program in June 2017. Calgarians already separated their recycling into blue bins and their garbage into black bins for curb-side pickup. The green carts added separation of organics.
“It’s the story of two cities,” McCartney said. “It’s form of ironic. Edmonton was way ahead… and Calgary waited and it’s built the newest and best.
“Calgary’s facility is sweet… their final product is a superb, clean product. I’ve done some testing and I wouldn’t hesitate to recommend that… It’s quite a cheap process as well.”
The Edmonton Cart Rollout pilot program was launched in April 2019. Eight-thousand homes received a green cart for food scraps (organics) and a black cart for garbage. Residents were asked to proceed separating their recycling and setting it out in blue bags. Yard waste is picked up on the curbside twice within the spring and twice in the autumn and is composted on the Edmonton Waste Management Centre (EWMC) cure site.
Edmontonians also can do their own residence composting and leave their grass clippings on the lawn.
Edmonton Cart Rollout was speculated to expand city-wide in summer 2020 however the COVID-19 pandemic postponed the launch. The pilot phase will proceed into spring 2021, when the city-wide rollout is anticipated to start.
“All remaining single-unit homes in Edmonton will follow an analogous routine once they receive a food scraps (green) cart from March to fall 2021,” Anna Kravchinsky, spokesperson for town’s waste services, told Global News.
Edmonton has just a few things coming down the pipe in 2021 that can improve its composting numbers: more food scrap (organic, or green) carts, the brand new High Solids Anaerobic Digestion Facility operating at full capability and processing capability from regional partners becoming available.
“At the moment, the vast majority of town’s organics will probably be diverted from landfill,” Kravchinsky explained.
In May 2019, the Edmonton Composting Facility closed attributable to the roof being structurally unsound. The town said it’s currently “almost fully deconstructed.”
Meaning there’s less processing space on the EWMC, where the separating and sorting of organics from general garbage takes place (on the Integrated Processing and Transfer Facility contained in the EWMC).
“In consequence, green cart organics from the pilot program and yard waste are prioritized within the remaining EWMC facilities,” Kravchinsky said. “Where possible, the IPTF is used so as to add additional organics to those locations when capability allows.”
Source or central separation
McCartney began consulting in the sector of composting within the late Nineteen Eighties, when programs were just beginning to roll out in major Canadian cities. In 1993, he began researching organic waste systems and composting.
Generally, Canadian cities use two most important ways of separating organic waste from other garbage: source separation (when residents are asked to separate food waste from other garbage at their homes before town collects it) and central separation (when all residential waste is collected and delivered to a city facility, where organics are separated from other garbage).
“The City of Edmonton doesn’t have a source separated program,” McCartney said, but with the green cart pilot project, it’s moving in that direction.
Without delay, organics arrive on the EWMC in garbage bags, green carts, yard waste, and even from Eco Stations. Crews at the ability sort through residents’ waste, recovering the organics in the rubbish and sending it to the composter through a mechanical screening process.
“Currently, most organics are commingled with other refuse in black bags,” Kravchinsky said.
“These organics are mechanically pre-processed or separated from the opposite refuse, after which sent to one in every of the processing areas on the EWMC. Organic waste that will not be commingled with other refuse is shipped directly for processing.
“A small amount of the organics that’s commingled in black bags can also be extracted to be used within the High Solids Anaerobic Digestion Facility (HSADF).
“In spring 2021, Waste Services expects to have agreements in place with processing partners within the Edmonton region to make sure additional organics processing capability.
“This may be sure that organics collected within the city-wide Edmonton Cart Rollout get processed and diverted from landfill.
“This will even unencumber capability on the EWMC to process a bigger fraction of the commingled organics,” Kravchinsky said.
In 1999, Edmonton was the primary to construct a large-scale composting facility, McCartney said. On the time, it was the largest on the planet.
“They were leaders in that regard,” McCartney said.
“That they had this notion that using the massive drums and slowly breaking open the baggage that they might sort the organics… The technology worked quite well for about 50 per cent of the organics.”
But the opposite half of Edmonton’s organic waste was still mixed with the rubbish.
“Attempting to get that out was quite difficult,” McCartney explained. “It’s still difficult to get the systems pure… Unfortunately, that little little bit of contaminant is problematic.”
Even slightly piece of plastic or other waste in a supply of compost means it may’t be sold.
Comparing costs of every sorting method
You’ll be able to compare source- and central-separation techniques by cost per tonne, McCartney said. With source separation, it’s residents doing the separating, which saves town money, but people must be taught to accurately, accurately and consistently separate their household waste, which implies investing in public education.
“The final agreement within the industry is that you’ll want to spend between 20 and 25 per cent of your entire waste budget on education and public awareness,” McCartney told Global News.
With central separation, cities have to take a position more in sorting resources and technology but not as much in public education.
McCartney says one other measure is the capture rate (the proportion of organic matter that’s accurately captured) and the contamination rate (how much non-organic waste leads to the compost product).
The City of Edmonton can’t compare home-sorted versus centrally-sorted waste for the reason that pilot only includes 8,000 residences. Nevertheless, the Waste Services department agrees that having residents separate their organics at home first ends in “a much lower contamination level and the removal of of remaining contaminants on the EWMC is far easier.”
“Organics commingled with other waste in black bags ends in a high level of contaminants, making the sorting process tougher,” Kravchinsky said.
“In consequence, organics from green carts are much easier to process at the ability and produce higher quality compost when put next to organics which might be commingled in black bags.”
Learn from Seattle
Seattle has been capable of increase its capture rate and lower its contamination rate by investing in creative public education campaigns, McCartney said.
“They’re all of the things that cause contamination and developing programs to handle them.”
Those little plastic stickers on vegatables and fruits, as an illustration. The peel is compostable however the sticker is garbage. In response, Seattle created fruit sticker bingo. When a family filled all 20 spots with fruit stickers, they received a free bag of compost.