Summary

As part of its commitment to environmental issues, the province of Quebec has mandated new targets on diverting organic waste from landfills to reduce greenhouse gas emissions and make better use of waste. To meet this challenge and contribute toward solutions, a group of municipal partners together with Investissement Québec CRIQ and Gazon Savard Inc. and supported by GMF piloted an innovative mechanobiological treatment (MBT) system that separates and processes organics from garbage in a treatment facility. Participants learned a great deal about MBT and about trialing such technology and have helpful recommendations for other municipalities exploring similar options. 

Background

Organic materials such as food waste, garden waste, and paper make up about 60 percent of the 5.8 million tonnes of waste thrown out in Quebec every year. This presents several challenges to municipalities:

• They take up valuable landfill space;
• They emit greenhouse gases as they decompose; and
• They have potential value, for instances as sources of recycled material and compost.

A novel approach to waste separation

In many jurisdictions, the solution to reduce organic waste being sent to landfills is a three-way collection system, with a separate bin for each type of household waste (landfill, recyclable, and organic).

Recently, technology has been developed for organics and garbage to be separated after collection, through a process known as mechanobiological treatment (MBT). This kind of system makes waste separation simpler for households, as it allows them to divide their waste into only two streams, one for recycling and one for garbage and organics.

By 2016, this technology was ready for testing, and from 2017 to 2019 a group of municipal partners representing more than 80 Quebec municipalities agreed to join a pilot project. The partners involved were:

• Bellechasse Regional County Municipality (RCM), with a population of about 38,000
• L’Érable RCM, with a population of about 23,000
• L’Islet RCM, with a population of about 17,000
• The Régie intermunicipale de gestion intégrée des déchets Bécancour−Nicolet-Yamaska, which includes the Bécancour and Nicolet-Yamaska RCMs, with a total population of about 44,000
• The City of Saguenay, with a population of about 145,000

The challenge

Situated in rural parts of Quebec, these communities share a common challenge in waste collection: servicing a relatively small population over a large geographic area. In addition to its other benefits, the MBT approach can address such a challenge by reducing the transportation needs of a traditional three-way system. The pilot project sought to answer two questions:

1. How well would the MBT system work in a real-life scenario?
2. Is the system a functional and financially viable option for the municipal partners participating?

Approach

During the project, partners collected more than 150 truckloads of household waste (a total of 1,860 tonnes), which was separated using the MBT approach then processed over a six-week period into compost. For the sake of comparison, the pilot also collected some waste via a three-way system.

Results

The pilot found the following:

• Partners collected more than 150 trucks of household waste (a total of 1,860 tonnes), which was separated via MBT and then processed over a six-week period into compost.
• Compostable organics made up 49 percent of the waste collected, with some slight seasonal variation.
• The MBT system was able to divert 89 percent of these organics, of which 72 percent was composted.
• The compost produced by this kind of system is rated class B, which means it is considered “good compost,” with permitted levels of trace elements and foreign matter contamination. Potential uses include in forestry, road developments and revegetation of degraded sites.
• The estimated cost to process household waste via MBT was $98 per tonne, though this does not include any potential revenue from selling the compost or other components and could be highly variable depending on labour costs, choice of site and other factors.

The organics diversion rate of the pilot was higher than that achieved by three-way collection systems, which range from about 30 to 60 percent across Canadian municipalities. This would represent a significant reduction in the amount of organic waste being sent to landfills, which would in turn reduce greenhouse gas emissions produced by decomposition and transportation and extend a landfill’s useful life.

Despite the high diversion rates achieved through this new technology, for various reasons, none of the municipal participants has yet moved forward with an MBT system. However, they found that joining this pilot project was an important step in their decision-making process. Not only did it give them an opportunity to review various options for diverting organic waste, but it gave them a better understanding of the assets they have and the ways their individual situations affect how they can best meet this challenge.

Recommendations

While MBT was ultimately not the best fit for partners in this pilot project, it could be a good option for other municipalities looking for solutions to divert their organic waste. Here are some recommendations for municipalities interested in running their own pilots to consider.

1. Look at the infrastructure you have. Potential benefits of the MBT system as opposed to other options for diverting organic waste will vary depending on a municipality’s existing infrastructure, such as whether it already has a landfill site or a network of ecocentres. This should be taken into account when examining organics diversion systems. Pilot results were not necessarily applicable to the reality of waste processing in participating municipalities. It’s important to design such studies in such a way that local situations are taken into account throughout the process.
2. Plan to be flexible. It would be ideal to have a longer and more flexible schedule both in advance of and during the project.
3. Build strong partnerships. When working with numerous organizations, priorities and perspectives often differ, and it can be helpful to take the time to define these and build relationships at the beginning of a project. One option is to have an independent participant involved to ensure a neutral approach. Should a municipality be interested in moving forward with an MBT system, there could be cost savings by partnering with nearby municipalities on this new infrastructure.
4. Understand the market. In order to make informed decisions, municipalities will need detailed cost estimates, and they should be ready to perform the relevant studies, which could affect timelines. While the compost produced can be a source of revenue, that depends on the realities of the local marketplace; it’s worthwhile to research potential buyers as part of the research process.
5. Check all the boxes. There may be regulatory barriers to transporting and processing waste in new ways. It’s best to clear the project with relevant authorities before proceeding. In addition, as the quality and composition of household waste is unpredictable and can affect the MBT process, a preliminary waste study before beginning the project would be a good idea.

Summary

Like all landfills, Winnipeg’s Brady Road Resource Management Facility produces methane-rich landfill gas, which contributes to the city’s greenhouse gas emissions and carbon footprint. A collect and flare system was installed beginning in 2012 to reduce emissions, but the city wanted to explore the opportunity to benefit from the landfill gas by turning it into a source of revenue. This study assesses four scenarios for capturing, processing and selling landfill gas, and concludes that the preferred option is to convert the landfill gas into renewable natural gas to sell on the open market.

Background

The Brady Road Resource Management Facility, then called the Brady Road Landfill, opened in 1973 to receive solid waste from Winnipeg and the surrounding region. Located to the south of the city, it accepts both residential and commercial waste—a total of 315,500 tonnes in 2021. In 2011, Winnipeg’s waste disposal was responsible for close to 800,000 tonnes of carbon dioxide equivalent (tCO2e) in emissions, almost 15 percent of the city’s total.

Since 2013 the facility has shifted its focus from primarily garbage disposal to a more circular approach to waste management. For instance, leaf and yard waste from curbside collection is now processed on a nine-hectare composting pad into nutrient-rich compost, and a wood recycling program diverts ash trees and old lumber from the landfill, using it instead to create products like furniture and flooring.

In 2012, a system was installed to collect and flare landfill gas (LFG). Landfills produce this gas—primarily made up of methane, a potent greenhouse gas (GHG)—as organic waste decomposes. Collecting and burning LFG results in lower overall GHG emissions and provides other benefits such as reduced odours. The landfill’s system of gas extraction wells was expanded in 2017 and 2020 and currently includes 80 wells covering about 55 hectares of waste (65 percent of the total waste area). The city expects to further expand this LFG collection system over time, resulting in an increase in the amount of gas collected.

The challenge

While collecting and flaring LFG does reduce GHG emissions, it does not eliminate them. One possibility for further reducing emissions is to use the LFG collected as a source of energy. This fuel can offset demand for energy from other sources while also providing a source of revenue for the waste management facility and the community. The challenge the City faced was determining the best way to use this gas, both from a fiscal perspective and in terms of environmental and social benefits.

Approach

The City of Winnipeg commissioned a study to explore four different scenarios:

1. Generating electricity in an on-site facility, then selling it to Manitoba Hydro.
2. Processing the LFG into pipeline-quality renewable natural gas (RNG), then selling it on the open market.
3. Processing the LFG into a low-grade fuel and supplying it to the University of Manitoba.
4. Selling raw LFG to an independent power producer.

Each of these scenarios was assessed for potential costs and benefits over a 20-year period, as well as for additional environmental, social and economic factors such as reducing Winnipeg’s carbon footprint.

One issue under consideration, for example, was the expected output of LFG from the facility. The team assessed various factors such as organics diversion rates and capture efficiency to come up with a realistic forecast to base revenue estimates on. The maturity of each technology was a consideration as well, as was the presence of existing test cases elsewhere in North America. The analysis also evaluated scenarios for contractual risks and regulatory requirements.

Barriers

One difficulty in conducting this study was obtaining accurate revenue figures from potential markets. Representatives of these markets were often reluctant to provide these numbers. Therefore, conservative figures were used with contingency added where necessary.

Results

Following the analysis, two scenarios—selling RNG on the open market and selling raw LFG to an independent power producer—were found to have the potential of generating revenue for the city, with a net present value of $21.36 million and $4.26 million respectively. Since the estimated revenue from the RNG option is significantly higher, study authors recommended that the city proceed with a business case and further estimate to build and operate a facility that will process and sell pipeline-quality gas.

Benefits

The completion of this study opens the door for Winnipeg to proceed toward making use of the LFG that is currently collected and flared at the Brady Road Resource Management Facility. Not only will this have the benefit of generating revenue, but it will help Winnipeg reach the GHG targets outlined in its Climate Action Plan, as the RNG produced can offset energy produced by natural gas and other fossil fuels.

Lessons learned

One key lesson from this project is the importance of keeping all stakeholders informed and engaged throughout the study. Even if public consultation is not required, including it in the process can help reduce project delays down the road, for instance due to citizens wishing to discuss concerns with the city.

Next steps

In March 2022, council agreed to move forward in negotiations to become a supplier of raw resource LFG to a third party, which will convert the gas to RNG and then sell it on the market. This option was chosen as it presents lower risk and liability as well as a more diverse client base. In addition, associated revenues are to go into a new reserve fund for climate change initiatives.