Understanding the operational carbon footprint of Municipal Organic Waste Systems (MOWS) in Nova Scotia

Abstract

Municipal Organic Waste Systems (MOWS) such as composting and anaerobic digestion play a crucial role in reducing greenhouse gases (GHGs) emissions by diverting organic waste from landfills. This study quantifies the operational carbon footprint of MOWS in Nova Scotia, Canada, with a focus on two facilities: the Colchester Composting Facility and the Courthouse Hill Energy anaerobic digestion plant. Over one year, the research assessed physicochemical properties (TC, TN, C:N, MC, OM) and GHGs emissions (CO₂, CH₄, N₂O) at different decomposition stages (initial, in-process, final processed), employing direct measurement techniques including a non-dispersive infrared (NDIR) respirometric system and gas chromatography (GC) headspace measurement. Results were compared with the existing GHGs estimator for organic waste developed by Environment and Climate Change Canada. The findings revealed significant seasonal and operational variations in GHGs production rates and physicochemical dynamics, highlighting the importance of region-specific data for decision making. The study underscores the importance of accurate emissions data to inform policy, improve waste management practices, and support Canada’s net-zero goals through better life cycle assessments and GHG inventories.