Life cycle assessment of municipal solid waste management in the Region of Waterloo, Canada

Canada has emerged as the second-largest waste generator per capita, underscoring the urgent need for sustainable waste management solutions. The Region of Waterloo, Ontario, exemplifies a rapidly growing urban area where municipal solid waste management (MSWM) systems must evolve to meet environmental challenges. This study conducts a life cycle assessment of three MSWM scenarios in the Region. Scenario 1 models a business-as-usual system where the kitchen and yard waste go to composting, the recyclables are recycled, and non-reclables (residual waste) ends up in lanfill with energy recovery. Scenario 2 replaces landfilling and composting with incineration and anaerobic digestion, respectively. Scenario 3 is the same as Scenario 1 in terms of MSWM pathways except forreasing material recovery rates in line with extended producer responsibility (EPR) targets, thereby reducing the fraction of waste sent to landfill.The functional unit is set to management of 1 ton of municipal solid waste in the Region of Waterloo. Results show clear differences in environmental performance across the scenarios. Scenario 2, which uses incineration for residuals, has the highest environmental impact, particularly in terms of global warming potential over a 100-year time horizon (GWP100), fine particulate matter (PM2.5), and eutrophication. In contrast, scenario 3, which introduces increased recycling rates in response to the region's EPR targets, performs the best overall, achieving substantial environmental savings; 134% reduction in GWP100 and 95% in photochemical ozone formation compared to the business-as-usual scenario. Overall, the findings emphasize how strategic choices in MSWM system design can lead to substantial environmental benefits or burdens.