Policy-driven municipal solid waste management assessment using relative quadrant eco-efficiency: A case study in Malaysia

Despite studies encouraging sustainable waste management, most municipal wastes remain in landfills, particularly in developing countries. Lack of holistic planning and national policy alignment might impair the waste management facility implementation. Policy-driven waste treatment scenarios should be designed to strongly link to the local conditions when assessing the eco-efficiency impacts of the waste management system. Taking Malaysia as a case study, a relative quadrant life cycle eco-efficiency indicator is developed to investigate the eco-efficiency of waste treatment scenarios. The relative quadrant life cycle eco-efficiency indicator depicts the eco-efficiency of various waste management scenarios. Compared with Scenario S1 - business-as-usual (i.e., 71.5% open landfill, 10% sanitary landfill, 1% composting, 17.5% recycling), five waste treatment scenarios (S2-S6) are designed based on Malaysia's existing and future policy targets. Scenario S5 (15.5% sanitary landfill, 22.25% composting, 22.25% anaerobic digestion, 40% recycling) and Scenario S6 (5% sanitary landfill, 22.25% composting, 22.25% anaerobic digestion, 40% recycling, 10.5% incineration) demonstrate that the 40% recycling rate is 32.9-33.6 times more environmentally favorable and 10-20% more economically viable than business-as-usual. Another four scenarios (NS1-NS4) are designed to investigate zero waste in landfills and the need to implement incineration or material recovery. Scenario NS3 suggests increasing incineration capacity to 33% could be an option should incineration is implemented. Adopting home or centralized windrow composting and increasing 2.5-5.5 times of current Feed-in Tariff rates are recommended to improve the eco-efficiency of the waste treatment scenarios. This study could facilitate policymakers to set waste minimization targets and incentives through various scenarios via sensitivity and comparative analyses.