Assessment of Greenhouse Gas Emissions from Ontario's Solid Waste Landfills: Assessment of Improvement Scenarios

Actual data of greenhouse gas (GHG) emissions from Ontario's large landfills were compared with data generated by a first-order decay model. Different scenarios were developed and compared based on their associated GHG emissions. The life-cycle modeling was made for municipal solid waste (MSW) landfilled until 2015, and the environmental aspects were evaluated for a 100-year period after disposal. The data utilized in the calculations to model the municipal solid waste landfilling scenarios make extensive use of site-specific data from the landfills. The assessment of different scenarios showed that reduction of landfilled organic waste can lead to significant reduction in the potential environmental loads with respect to global warming when compared with the current MSW landfilling. Conventional landfilling with gas collection for electricity generation showed a better performance than the flaring scenario. Landfill gas collection and power generation resulted in a reduction in GHG emissions of up to 78% relative to the methane flaring scenario. Utilization of soil top covers to oxidize methane (use of methanotrophs) has been demonstrated to drastically reduce environmental burdens.