BioCycle August 2010, Vol. 51, No. 8, p. 36
With wide acceptance of Green Bin organics collection, Toronto and the surrounding four regions are tackling the challenge of increasing processing capacity.
TORONTO, Ontario’s capital, and each of the four regional governments around it – which combined are known as the Greater Toronto Area, or GTA – have young but well-entrenched programs for curbside collection of kitchen scraps and other organic leftovers for processing into compost. All are successful, so much so that one of their main difficulties is coping with the increasing quantities that residents are sorting and putting out for weekly collection in what are called Green Bins or Green Carts. And enthusiasm has replaced skepticism as officials contemplate their next steps.
“The challenge is processing capacity,” says Trevor Barton, supervisor of waste planning with Peel Region, an umbrella government for two cites and a town, with a total population of about 1.2 million, immediately west of Toronto. “We’re bursting at the seams. The people participating are doing it very well.”
Erin Mahoney, commissioner of environmental services in York, the northernmost region with a population of one million, agrees. “There’s a real supply-demand challenge,” she says. And the story is the same in Toronto and the two other suburban regions – Halton, to the west of Peel, and Durham, on Toronto’s eastern border.
The capacity crunch is partly the result of problems, mostly related to odor complaints, which forced some organics processors to temporarily reduce or shut their operations. But it’s driven mainly by the fact that the amount collected continues to rise.
The City of Toronto launched Green Bin collections with a small pilot project eight years ago. By 2008, it and the regions had programs servicing virtually all their single-family dwellings and townhouses – any homes where the bins could be set out at the curb for pick-up by municipal or contractors’ crews.
With their first phases nearly complete and widely accepted, all are working to entice the single-family holdouts and, more importantly, to achieve the much more difficult expansion of organics collection to multiunit buildings. Add a fast-growing population – the GTA is home to 5.9 million people and is among Canada’s top draws for immigrants – and higher per capita recycling as the programs improve and residents get accustomed to them – and it’s no wonder Toronto and the four regional governments are developing long-term plans, focused on new processing facilities, to ensure sufficient capacity.
PROGRAM SIMILARITIES – AND DIFFERENCES
While all the programs operate in roughly the same way, there are significant differences. For example, Toronto – a densely populated city of 2.6 million, with half its residents in high-rise buildings – in particular has unique needs and solutions.
Each region takes almost any food wastes, including bones, as well as soiled tissues and napkins, paper-based food containers, coffee grounds and filters and houseplants. Residents generally put this material into a small, beige in-home kitchen collector lined with a paper towel, newspaper, compostable bag or paper bag. (Toronto, as discussed later, allows use of plastic bags to line the kitchen collector.) Residents carry full bags to forest-green, 13-gallon Green Bins, depending on the region, which are manufactured by Norseman Environmental Products. (A few programs are testing Norseman’s larger 21-gallon cart, which can be used with automated collection trucks.) Bins typically are kept outdoors or in the garage.
Once a week, city or contractors’ crews empty the carts into packer trucks with two compartments – one for organics and the other for the glass, paper, cardboard, plastics and metals that residents put out for recycling in Blue Boxes or carts. Materials are taken to transfer stations (each government has several) where Green Bin and Blue Box materials are dumped in separate piles, then loaded onto larger tractor-trailer trucks for transport to the appropriate processing facilities, some government-owned, others belonging to private contractors.
Apart from a portion collected within Toronto, the organics – usually combined with leaves and yard trimmings from separate collections from spring through fall – are composted aerobically, inside buildings or under specially designed covers, in a process that takes eight to 12 weeks.
Nearly half of Toronto’s loads go to a city-owned anaerobic digester, operated under contract by Canada Composting Inc. The digestate still contains pathogens and usually lacks the required carbon content, so before it can be applied to gardens or farms it must be combined with other materials and aerobically composted and cured.
Each region says its compost meets the AA standard being established under Ontario’s new regulations. That designation, the highest of three, permits it to be used anywhere, including on food crops. Some give small amounts of compost to residents at local annual recycling promotion events called Environment Days. The rest is sold to homeowners, landscapers and farmers, or to a developing market for erosion control on highway construction projects.
Revenues from these sales are a small fraction of the cost of collecting and composting the organics, which ranges from about $120 to $155/ton. But officials say the expense – roughly half again as much as collecting and disposing of garbage – is justified.
“It’s well worth it,” says Rob Rivers, director of Halton’s waste management program. His region expects organics recycling will extend the life of its only landfill by at least seven years, to 2031. That’s a major gain, he says, when, “it’s extremely tough to get new sites.”
NOT SO YUCKY
Officials say they’re surprised at how quickly attitudes toward organics recycling have changed. When the idea was first raised, critics scoffed that only the greenest of residents would separate their food scraps instead of dumping them into the trash. The biggest impediment was what Geoff Rathbone, general manager of Toronto’s solid waste management services, describes as the “yuck factor.”
But that has faded as an issue: In the type of homes where Green Bin collection is offered, it’s as easy for residents to put organic wastes into their kitchen bucket as into a garbage can, and there’s little fuss involved with taking those small loads to the bigger bin outside. In fact, most of the regions employ organics’ “yuckiness” as one of their strategies to encourage its recycling. Apart from Peel, all collect Green Bin and Blue Boxes once a week, but have reduced garbage collection to every two weeks. People don’t want their kitchen scraps sitting around for two weeks, says Halton’s Rivers. “The weekly collection of Green Bins is, by comparison, very attractive.” Adds Mahoney in York Region, “It motivates people to use the Green Bin.” Peel cites its continued weekly garbage collection as one reason its organics recycling participation rate is only 45 percent, far lower than the other four jurisdictions achieve.
All of them limit the amount of garbage residents can put out for collection while imposing lenient or even no limits on Blue Box and Green Bin materials. Some allow only two bags of trash or one can with a maximum size limit. Toronto provides a choice of five garbage bin sizes – with an annual fee rising with each step-up in capacity.
Peel’s instruction to residents is explicit: The bag limit, reduced from three to two when organics collection was introduced, “is intended to encourage you to maximize use of your Green Bin and recycling boxes,” the region states on its website. However, it hasn’t had much impact since 90 percent of residents were already within the new limit.
All five regions have concluded that education is key, and operate programs in which students learn how to manage organics in the schools and are encouraged to take the recycling message home. That’s good news for George White, who runs a composting facility called All Treat Farms Ltd., in the agricultural community of Arthur, about a three-hour drive northwest of Toronto. Quality organic material is essential to producing good compost and the GTA’s, while improving, is far from perfect, he says: “I wish there was more emphasis at the elementary school level. Kids keep an eye on their parents.”
A more controversial inducement, being considered by some of the GTA governments, is to require that residents put out their garbage in clear bags. Such a regulation would make it harder to conceal items that should be recycled, but officials cite privacy concerns among reasons for their go-slow approach. Durham “is evaluating clear bags as part of its larger plan to reach 70 percent diversion of waste from landfill,” says Peter Veiga, the region’s supervisor of waste operations.
A pilot test of clear bags produced a slight diversion increase, but it wasn’t certain if that was from their use or an extensive promotion and education campaign, including several visits to every household in the study area. “It would be unrealistic to expect that level of support could be replicated across the region,” says Veiga, noting that Guelph, a small city about 90 minutes west of Toronto, has used clear garbage bags for years and its diversion rate is lower than Durham’s.
The GTA’s collection workers are relatively aggressive in rejecting improperly sorted wastes. If they spot garbage among recyclables, or detect organics in the trash, they’ll leave the offending items behind, often with a note explaining the transgression.
PLASTIC BAG CONUNDRUM
Such detective work also involves them in another contentious issue: Should regular plastics be allowed in the Green Bin stream? Durham, Peel and Halton say “no.” They don’t allow plastic-lined products such as disposable diapers in their Green Bins and require that all organic wastes be contained in bags made of paper or biodegradable plastic. Craig Bartlett, Durham’s manager of waste management operations, and other officials explain that conventional plastics must be removed before composting begins. This step adds to the expense, and doesn’t capture all of the unwanted material, which compromises the quality of the end product. In addition, inevitably, some of the organic matter sticks to the bags, says York Region’s Mahoney. That portion amounts to about three percent of the total organics content – significant when trying to push waste diversion as close as possible to 100 percent.
York, with one million residents in 260,000 households, still allows noncompostable plastic but expects to switch to mandatory compostable varieties next May, Mahoney says. Such a shift would leave Toronto alone in not just accepting plastic bags, but also actually insisting on their use. The city accepts plastic-lined disposable diapers and sanitary pads, too, and will continue to do so, Rathbone says.
It does so because the city is, to date, unique among the GTA regions in having so much of its organics stream flow to an anaerobic digester. At the start of the process, the wastes go through a hydropulper, which shreds the bags and mixes the organics with water to create a slurry. The plastics rise to the top of the swirling liquid and are skimmed off. This residue – nearly 20 percent of the Green Bin contents – is sent to a landfill, along with the “heavies,” including glass, large bones, stones, batteries and a long list of other unwanted items that get tossed into the bins. That fraction is captured in the bottom of the hydropulper as well as via a hydrocyclone.
A machine resembling a large horizontal plunger inside a pipe squeezes the water and most residues from the plastic. The entire process leaves barely noticeable traces of plastic – smaller than grains of rice – that have no impact on the final compost’s quality, Rathbone says.
The system could handle compostable bags, although they wouldn’t biodegrade before they’re removed from the slurry. But the city doesn’t want residents using them at all. It recycles plastic bags through the Blue Box. If even a few compostable bags were put among regular plastic versions, they’d contaminate the entire load, making it unfit for recycling, according to Rathbone.
SERVICING MULTIFAMILY UNITS
Toronto’s preponderance of high-rise apartments and condos also influenced the decision to require plastic bags for organic wastes, and to allow disposable diapers and sanitary napkins, as well as kitty litter, in the Green Bins. Half of the city’s one million households are in multiunit dwellings; in contrast, the four suburban regions are still dominated by single-family homes and town houses. Most of Toronto’s buildings have only a single chute for garbage, which means residents must carry their Blue Box and Green Bin materials to bins or bulk carts in a central location, usually a dingy basement room.
For that to succeed, it’s imperative that residents have confidence the bags won’t leak or split on their way to the central depot or while they’re waiting there to be picked up. Even without the threat of spills, it can be difficult to persuade residents to lug their wastes downstairs.
Toronto is leading the GTA in this area, too. After a small pilot project, it has introduced organics recycling to about 15 percent of its multiunit buildings. The quantity being collected – an average of 143 lbs annually per unit – is less than the 165 pound target and far below the almost 500 pounds produced by the average household with curbside pick-up. But, Rathbone notes, the Green Bin is a young program, “just finding its feet.” In the past 24 months, “we’ve seen a fundamental shift in how apartments handle wastes. There’s much more recycling and interest in bringing Green Bins in.”
Biweekly garbage collection, which Rathbone says “drives” recycling in single-family homes, isn’t an option for multiunit buildings. Because the trash might contain food wastes it simply can’t be held that long. But the city uses a financial incentive: It charges apartment owners for garbage collection but not for recycling. If they adopt both the Blue Box and Green Bin they can halve the annual $310 per unit fee that’s charged when there’s no waste diversion.
Toronto also requires that new buildings be designed to make recycling “as convenient as disposal,” Rathbone adds. The actual mechanism is left to the discretion of the building owner. Options include eliminating chutes entirely so that all wastes must be carried down to a common ground-level location.
Until now, organics diversion from multiunit housing has been a low priority in the other regions, but that’s changing as they run out of land for sprawl-style development. York Region expects to add 500,000 people to its current million over the next three decades, and most will be accommodated in high-rise buildings, Mahoney says. “We need a policy that requires three-stream equipment in all those new buildings. We haven’t specified three chutes. We’ve said separation, so the means of complying is to be determined. Three chutes is the minimum standard.”
In the GTA’s complex political structure, the regions beyond Toronto are generally responsible for processing wastes, but the towns and cities within them look after collection as well as many aspects of building codes. That means the regional governments can’t simply issue decrees. But Mahoney is optimistic. “It’s just going to happen. We’re working with our 9 municipal partners to make it happen. We see it as a challenge we need to get ahead of.”
Halton is beginning a year-long pilot project at five buildings, “to work out the pros and cons and challenges for a program to take to the rest of the region,” Rivers says. “The big issue is storage and timely collection before the material becomes a nuisance.” A bylaw that would require new buildings to make Blue Box and Green Bin recycling convenient is being considered.
Peel, too, is looking at solutions for its current 800 multiunit households and the many more to come, Barton says. Tests have shown that the compostable bags the region requires have enough integrity to withstand the trip to the basement, but “I can’t see people taking their kitchen collectors 20 stories down,” he says. “It’s a chute issue.”
New construction will be relatively easy; retrofits would be very expensive, Barton adds. In any case, Peel isn’t pushing expansion into high-rises until it gets more processing capacity.
On consecutive days in July, two of southern Ontario’s major composters – the OrgaWorld Canada Ltd. facility in London and Universal Resource Recycling Inc. in Welland (near Niagara Falls) – announced temporary shutdowns to solve problems with odors. They needed to improve their ammonia scrubbers, chimneys and air handling.
The temporary closures due to odors highlight the need for the jurisdictions establishing diversion programs to ensure that the contracted facilities have the capability to manage the volumes being received. Lambert Otten, an independent consultant and former faculty member at the University of Guelph, says the GTA municipalities contributed to the current situation. Running out of landfill space, and with growing amounts of organic wastes, they contracted with some operators who lacked the capacity and capability to deal with them all; as a result, “the odors were horrendous,” Otten says.
The closings, expected to last at least two months, created major challenges for Toronto and York Region, which send organic wastes to those plants, and highlighted just how close to the edge of capacity the GTA is. York depends on both facilities for most of its Green Bin recycling. It managed to find a facility in Massachusetts that would handle about 20 percent of its organics stream during the emergency, but until OrgaWorld and Universal are operating again, the region must landfill the rest, Mahoney says.
Toronto’s situation isn’t quite so dire: Nearly one-third of its annual 121,000 tons/year of residential organic wastes goes to the anaerobic digester it owns in the city’s north end. OrgaWorld is one of four composting facilities it uses under contract to handle the remainder. The London plant processes 25 percent of the city’s stream. Toronto planned to make up for the lost capacity by negotiating an increase with one of the other contractors, and ramping up the amount processed in its digester, Rathbone explains. Still, “only as a last resort,” it might need to landfill up to 4,500 tons. The crisis “points out the importance of (City) Council’s recent decision to build a second new state-of-the-art digester facility,” he says.
Throughout the GTA, all but the portion that goes to Toronto’s anaerobic digester is processed via composting. Green Bin materials are shredded and combined with leaves and yard trimmings to produce the desired texture, moisture level and carbon and nitrogen balance. Peel and Durham own their own processing sites, but, as Toronto does with its anaerobic digester, they contract much of the operating work to private operators. Halton and York send all their wastes to contractor-owned facilities.
A common composting method is to pile the material in rows or “heaps” (54.5 yards long, 9-yards wide and 3.3 yards high), situated over aeration channels through which a fan blows air. Covers are pulled over the rows and the material begins to cure. Computerized sensors monitor oxygen levels, moisture content and temperature.
Systems vary but one of the most popular in Ontario, designed by W.L. Gore and Associates, of Newark, Delaware, uses oxygen levels to control the process. When probes indicate more of the gas is needed by the bacteria that break down the matter, the fans switch on and blow air along the aeration channels. Some of it works through the heap and is trapped by the cover, which balloons out, creating a supply of oxygen for the material near the outer edge.
After using 12, often problematic, contract processors since it launched the Green Bin, Toronto is determined to become self-sufficient. Its first digester, which opened eight years ago, was built as a pilot project, but has consistently processed more than its rated capacity of 27,500 tons/year. Engineering work is underway on the new $74 million west-end anaerobic digestion plant, rated at 81,600 tons and to open in 2012. With it, “we’ll be close to self-sufficiency but not fully,” Rathbone says.
Once the new plant is operational, the original plant will be rebuilt to the same capacity. And, Rathbone says, his department is “starting” to look at a third digester in the city’s northeast corner. The methane produced by the digestion process at the original plant is flared, but the new facilities will capture it to be cleaned and added to the natural gas supply.
Peel has pinpointed, but not yet acquired, a site for a new centralized processing plant, that might combine aerobic and anaerobic digestion, or might employ something entirely different, Barton says. “The sky’s the limit about the type of technology. We’re going out, worldwide, with a request for proposals. There are a lot of exciting ideas.”
His region, too, intends to own and operate its own plants. “We’ve got good quality, trained staff. We’ll control the processing. We talk about a made-in-Peel solution.”
York also intends to take more control by owning and operating its next plant. It’s working with a neighboring rural county, which has a site, to build a 55,100 tons/year plant to be in operation by 2013. The region will own 90 percent of the project, with the county owning the rest. Instead of specifying any technology, the request for proposals set out performance standards, Mahoney says. Whether the treatment is aerobic or anaerobic, the process must occur indoors, the plant must have 100 percent redundancy in odor control, and all the compost must meet the new AA standard.
Durham and Halton are also embarking on long-term plans, but not with the same urgency. Halton now ships its organics to a plant in the nearby city of Hamilton operated by AIM Environmental Group. “For the short term, we’re quite content,” Rivers says. “For the longer term, we may have to come up with our own capacity. We’ll be looking. Everything is open.”
That, it seems, is the enthusiastic view of organics recycling throughout the GTA.
Peter Gorrie is a free-lance writer based in Toronto, Ontario.
Sidebar p. 40
TONS IN AND OUT IN TORONTO
OF every 100 tons of organic waste that arrive at Toronto’s anaerobic digester:
• 18 tons of plastic bags and other light wastes are removed and sent to landfill
• 1.5 tons of heavy contaminants, from large bones to batteries and chunks of metal, are removed and sent to landfill
• 1.5 tons of “grit,” including small pieces of metal, plastic and glass, are removed and sent to landfill
• 11 tons become biogas
• 33 tons is water
• 35 tons is digestate that’s mixed with yard trimmings and other materials and cured aerobically to produce compost
Sidebar p. 42
RESIDENTIAL ORGANICS PROGRAMS AT A GLANCE
Amount collected: 27,558 tons/year
Participation rate: About 85 percent (where offered)
Amount/household: 333 lbs/year
Destination: Miller Composting; 27,558 tons/year plant using Ebara wide-bed, in-vessel aerobic technology.
Amount collected: 30,314 tons/year
Participation rate: Urban, 60 percent, Rural, 77 percent (where offered)
Amount/household: 606 lbs/year
Destination: AIM Environmental Group aerobic composting facility in Hamilton, Ontario, using in-vessel tunnel technology developed by Netherland’s-based Van Kaathoven Groep.
Population: 1.2 million
Amount collected: 37,479 tons/year
Participation rate: 45 percent (where offered)
Amount/household: 287 lbs/year
Destination: Most goes first to region-owned Peel Integrated Waste Management Facility, in Brampton, for initial composting using Christiaens Group composting tunnels. Remainder goes to Caledon Composting Facility, in Caledon, for initial composting using Herhof Biocells. All initially treated material is cured at the Caledon site, using GORE Cover System. Less than 1,100 tons of overflow goes to All Treat Farms.
City Of Toronto
Population: 2.6 million
Amount collected: 121,254 tons/year
Participation rate: >90 percent (single-family homes)
Amount/household: 496 lbs/year
Destination: One-third goes to city-owned Dufferin anaerobic digester using BTA process, licensed to Canada Composting. Digestate from Dufferin goes to All Treat Farms Ltd., in Arthur, where it’s mixed with leaves and yard trimmings and other organic materials for processing in GORE Cover System. Remainder of Green Bin organics go to Orgaworld (Canada) Inc. plant in London, Ontario, using Orgaworld tunnel aerobic process; Universal Resource Recovery Inc., near Niagara Falls, using Transform Compost Systems Inc. process, with automated turning; a site operated by Miller Waste, in Courtice, within Durham Region; and Laflèche Environmental Inc., near Ottawa, with an enclosed agitated and aerated channel system.
Population: 1 million
Amount collected: 100,310 tons/year
Participation rate: 80 to 90 percent (where offered), varying among York’s 9 member municipalities
Amount/household: 661 lbs/year
Destination: Most goes to Orgaworld (Canada) Ltd., in London and Universal Resource Recovery Inc., in Welland (see Toronto section). Both were temporarily closed to deal with odor problems. As a result, 20 percent of SSO goes to WeCare Organics, in Marlboro, Massachusetts.
August 17, 2010 | General
Greater Toronto At Full Steam With Residential Organics Programs
BioCycle August 2010, Vol. 51, No. 8, p. 36