Our Projects: Toronto, Ontario

Green Bin Program

Established by the City of Toronto in January 2001, the Waste Diversion Task Force 2010 began work on a ‘made in Toronto’ solution for waste diversion. The group targeted a goal of 30 per cent diversion by 2003 and 60 per cent by 2006. One of the key proposals in the Task Force report, “Beyond Landfill: A Diverting Future”, included a system, now called The Green Bin Program. About one-third of Toronto’s waste is organic material.

Unique Generator Practices

The purpose of the Green Bin Program is to divert and convert a broad range of acceptable materials from landfill and convert them into renewable energy and other beneficial use products. Toronto’s Green Bin Program is one of the most successful waste diversion programs on the continent and will divert millions of tonnes of organic material from going to landfill over the next 20 years. The primary pillar of success was to create an environment for Torontonians that would maximize convenience.

Residents and businesses use plastic bags as bin liners and can include a broad range of acceptable materials, including hard-to-process elements such as disposable diapers, incontinence products, feminine hygiene products and pet waste. With this approach, Toronto has produced one of the highest rates of diversion per household in North America.

Program Highlights

The Green Bin Program changes the way single family household residents and commercial businesses participate in the City’s garbage and recycling programs. The three stream collection system, employing source separation of recyclables and organics, is critical to helping the City achieve its diversion goals. Source separation was chosen as it offers the best and most realistic approach for the City to maximize the value inherent in their waste stream. Highlights of the Green Bin Program include:

Program Background

In 1999, spurred by their rapidly diminishing land fill capacity, the City of Toronto (City) made a strategic decision to apply resources to the development of a residential and commercial organics diversion solution. Selected from 19 processing proposals was the BTA® Process owned by CCI. From September 2002 through March 31, 2014 the Dufferin Organics Processing Facility (DOPF) was the processing cornerstone for the Green Bin Program.

Commissioned in May 2002, the City owns the facility. It was developed under a fixed price, guaranteed, design/build/operate/maintain agreement with CCI and our partners.  CCI and partners operated the facility under contract to the City. The site is urban and also houses one of the City’s seven transfer stations and a material recovery facility. The DOPF accepted the first Source Separated Organics (SSO) in September 2002 to coincide with the start of the Green Bin Program rollout in which residential and commercial sources are separately collected for processing. The facility was temporarily closed in the spring of 2014 and will reopen in 2017 when the second step of a 2 phase expansion plan is completed.

Today, the City collects over 130,000 metric tonnes of residential and commercial SSO annually, of which up to 55,000 metric tpy will be processed at the DOPF when the facilty is re-opened. A second BTA footprint at Disco Road with a 75,000 metric tonne annual capacity began converting a portion of the repatriated volumes in December 2013. The remaining tonnage is composted by external service providers. Once the DOPF expansion is completed, more than 130,000 metric tonnes of SSO will be converted at these 2 City owned AD facilities.

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Processing Highlights

The facility initially operated two shifts daily, Monday through Friday, for receiving and processing. In the early life of the facility there were several extended intervals when the City had asked for a third shift and some weekend processing to manage the lack of reliable external capacity to process the remaining volumes collected in the program. In 2009 this practice became permanent when a third shift was added.

The waste feedstock, which is characterized by a high plastic content due to the collection in plastic bags, was directly fed to the BTA® Hydromechanical Pre-treatment system without any prior treatment. The anaerobic digestion methodology implemented is a single-stage wet digestion process in the mesophilic range with full mixing using compressed biogas.

The digestate was dewatered using screw presses and the solids were sent for aerobic finishing at an off-site composting facility. Due to the virtually non-existent inert contamination, the final Class AA quality compost was distributed into the high-value markets. The liquids from dewatering, primarily made up of the liquids inherent in the waste, plus any fresh water used for cleaning was reclaimed and recycled in the process using a closed-loop process water management system. The BTA® Process Control system monitored and controlled all equipment, including subsystems such as the bio-filter.

Delivery Team Partners

CCI was an equal partner in the joint venture responsible for both the initial build and the 2012 capacity expansion under a design, build, operate, maintain (DBOM) approach the City used to develop and operate the project. Equipment and services directly delivered by CCI under this structure included:

Performance Achievements

A broad acceptable waste profile helps maximize diversion achievement and the production of community based bioenergy. According to the City, the residential participation rate is running at greater than 91% and is primarily due to the ability for generators to use plastic bin liners to mitigate the “yuk factor”. These liners account for close to 50% of the inert contamination, which averages 14%, as per the actual audited findings.  Some compelling facts about the history and performance of the facility include:

Doubling Capacity since 2012

The consistent results and reliable operations have birthed an expansion plan to double conversion capacity to 55,000 metric tonnes annually. In August 2012 a second digester was started-up , signifying the completion of the first step in the expansion plan.  In step two in 2015 a City decision will be made to double the pre-treatment system capacity.

The biofilter will be expanded and a new tip floor and other building and site improvements are planned. A cogeneration system will be installed to produce electricity and heat for the organics facility, the transfer station, and other buildings on the site. The robust, open architecture of the BTA® Process Control System allows for the integration of the monitoring systems of these types of modular subsystems.

Program Background

With the proven every day performance of the DOPF as the foundation, together with our strategic partners, AECOM Canada and Veolia Canada, we designed and built a second AD plant, owned by the City, to process 75,000 metric tonnes of SSO collected in their Green Bin Program. The facility received its first waste in December 2013 and reached full capacity in March 2014. Today, CCI provides daily operations, management and technical support.

Today, the City collects over 130,000 metric tonnes of residential and commercial source separated organics (SSO) annually, of which up to 55,000 metric tpy are to be processed at the Dufferin facility in 2017 once the facility capacity has been expanded and the plant is at full capacity operations. Any remaining tonnage beyond the 130,000 tonnes will be sent to external composting processors and the plan is to repatriate it back into the internal City owned processing system sometime in the future.  The City expects to collect more than 175,000 metric tonnes annually once all of the 4,000 plus apartment buildings are implemented with the Green Bin.

The City chose to construct the facility at the Disco Road transfer station, an urban location and one of seven in the City solid waste infrastructure.  It is integrated into the site operations and is physically built on an old landfill. More than 95,000 metric tonnes of material was excavated and sent for safe disposal using more than 3,300 truck trips. Over 900 steel pilings were then driven into the ground and filled with rebar and concrete to create the solid base required for foundation, building, tank and equipment loading.

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Processing Highlights

The facility operates two shifts daily, Monday through Friday, for receiving and processing of 300 tonnes per day, 250 days per year. The total plant staff compliment is 14 people, including the plant manager, administrator, lab technician, three maintenance staff and two 4 person crews. A person is on call each weekend and statutory holiday to monitor the plant and address any alarms or warnings. The composter does not receive materials on weekends and holidays. The digester solids trailers are staged on the tipping floor over the weekend and shipped the next processing day.

The waste feedstock, which is characterized by a high plastic content due to the collection in plastic bags, is directly fed to the BTA®Hydromechanical Pre-treatment system without any prior treatment. The configuration includes three waste pulpers and three grit removal systems to remove the inert contaminants and other non-digestible elements. The system is fed using a telescopic loader to fill a hopper that conveys the SSO to the pulpers, which have a load volume of about 15 metric tonnes.

The anaerobic digestion methodology implemented is a wet digestion process in the mesophilic range using two 5,300 m3 digesters with full mixing using compressed biogas. The plan for the continuously produced biogas is to cogenerate it to produce electricity and heat for the organics facility needs, the on-site transfer station, and the adjacent works yard to offset electrical and natural gas purchases. The first use of the biogas is to power the dual fuelled boilers to create the heat required for the digestion, biofilter, and wastewater systems.

The digestate is dewatered using two centrifuges, with the third installed as a stand-by unit. The resulting digester solids are then shipped for aerobic finishing at an off-site compost facility located about 100 kilometres from the plant. Due to the virtually non-existent inert contamination, the final high quality compost is Class AA and is distributed into the higher-value markets. All liquids inherent in the waste are reclaimed and reused as process water in the closed-loop process water system. Any excesses are treated on site in a biological effluent treatment system prior to discharge to the local sanitary sewer system.

The extracted inert contamination is dewatered, conveyed and loaded in trailers for landfill disposal City owned and operated site. Alternative uses for this material are being studied. The BTA® Process Control system monitors and controls all equipment, including subsystems such as the biofilter and the effluent treatment.

Delivery Team Partners

The facility is designed, built and guaranteed by CCI and partners AECOM Canada, ES Fox Construction, and BTA International. Initial operations commenced in December 2013 with CCI being a key member of the operating team that is led by Veolia Water Canada. Equipment and services delivered by CCI under this structure include:

Community Value Level

The City plans to cogenerate the biogas produced from the anaerobic digesters to produce electricity and heat to offset the needs of the facility, the overall site, and the adjacent works yard.  Public consultation is complete and the plan is to have a system procured and installed before the end of 2016. As an alternative the City will explore in the future, the Disco and Dufferin facilities could produce enough biogas to create more than 9 million cubic metres of biofuels, which is enough to power the entire waste collection fleet. The added-value this facility delivers to Torontonians’ includes: