Evaluating the Climate Change Mitigation Potential of Innovations at Greenway Wastewater Treatment Plant - City of London

The City of London will conduct a study to assess and maximize the potential GHG emissions reductions from the Organic Rankin Cycle (ORC) installation. It will also assess the potential of additional GHG emissions reduction from using the Fat Oil and Greases (FOG) collected from a scaled-up municipal collection program as supplementary fuel in the Fluidized Bed Combustion (FBC).Currently, FOG waste ends up either in a landfill (converted to methane), an anaerobic digester to produce biogas (primarily methane), accumulates in sewer lines, or is removed from wastewater and processed by biological treatment (a high-cost process involving microorganisms). The ORC installation would use FOG directly as biofuel to offset the treatment plant’s natural gas use and electricity demand from the grid, both possibly reducing GHG emissions. The climate change mitigation benefits may also include reducing landfill waste, reducing methane emissions, reducing emissions and material waste from replacing broken sewer infrastructure, and reducing emissions from powering the biological treatment of FOG. There is also the possibility of reducing water pollution by reducing the amount of FOG in wastewater effluent. Climate change adaptation benefits may include increased resiliency in the instance of grid power outage by having stored waste FOG as a fuel, and reduced flood risk in the case of extreme weather from the enhanced capacity of the sewer network.This study will include a calculation of current GHG emissions of waste water treatment facility FBC and FOG, an assessment of potential GHG emissions and an evaluation of adaptation benefits. In addition to the technical and operational analysis, consultations with stakeholders both within the municipal government and the larger community will be conducted to achieve this study.This study will help reducing the wastewater treatment plant GHG emissions. It will also prove and maximize the environmental benefits of a household-level FOG collection program, their subsequent use as supplementary fuel to power an ORC engine, and the emissions reductions from offsetting natural gas use with the ORC, among other sources.