Carbon Footprint of Municipal Solid Waste Management in Guelph City, Ontario

Abstract

More light is being shed continually on the environmental impacts of municipal solid waste due to the increasing amounts of waste generated and the related greenhouse gas emissions. Emissions from MSW account for 20% of Canadian greenhouse gas (GHG) emissions and accordingly, waste legislation in Ontario demands high waste recovery and a moving towards a circular economy. This study evaluates the current municipal solid waste management in the City of Guelph and assesses possible alternative scenarios based on the associated GHG emissions. Waste Reduction Model (WARM) that was developed by the US-EPA has been used to quantify the GHG emissions produced over the entire life cycle of the MSW management scenario. Sensitivity analysis was also conducted to investigate the influence of some scenarios on the overall GHG emissions. It has been found that one ton of landfilled waste generates approximately 0.39 ton of carbon dioxide equivalent (CO2Eq). It was also found that the current solid waste scenario has a saving of 36086 million ton of CO2Eq (MCO2Eq). However, the results showed that the scenario with enhanced waste-to-energy, reduction at source and recycling has resulted in a high avoided emissions (0.74 kg CO2Eq/kg MSW). The anaerobic Digestion scenario caused the lowest avoided emissions of 0.39 kg CO2Eq/kg MSW. The net avoided emissions for reduction at source scenario were found to be the same as that found by the current scenario (0.4 kg CO2Eq/kg MSW). The sensitivity analysis of both reduction at source and recycling rates show a linear inverse proportional relationship with total GHG emissions reduction.