Evaluating Landfill Diversion Strategies for Municipal Organic Waste Management Using Environmental and Economic Factors

Abstract

Municipal organic waste (MOW) contributes to greenhouse gas (GHG) emissions leading to global climate change. Incentives that encourage consumers to adopt MOW disposal strategies that minimize environmental impacts are needed. Policymakers must ensure that incentive programs align with environmental objectives and are economically competitive. The MOW disposal infrastructure in the city of Milwaukee, WI, was evaluated using a coordinated market model capturing the inherent value of environmental indicators (estimated with partial life cycle assessment methods) in the context of the city’s MOW supply chain. Tax programs are identified that incentivize consumers to reduce emissions through MOW disposal patterns. Results indicate that the existing MOW management infrastructure in Milwaukee incentivizes residents to minimize MOW GHG emissions by sending MOW to composting and digestion sites that have lower tipping fees and are located closer to the city (have lower transport costs). Therefore, limitations associated with MOW collection likely decrease alternative landfill disposal options. GHG reduction policy prioritizes anaerobic digestion systems for MOW disposal, but the outcome can be altered depending upon the tipping fees and transport distances. Composting and digestion hold few opportunities for reducing ammonia emissions from landfills, but there is a need to expand ammonia emissions measurements from landfill systems to improve model predictions as ammonia losses can redeposit, resulting in environmental issues and indirect formation of N2O.