Life Cycle Assessment of Shared Municipal Solid Waste Management Facilities in a Metropolitan Region

In Brazil, there are densely populated metropolitan regions, motivated by a great migratory flux in the 1970s. One of the consequences is the increased per capita municipal solid waste generation, which has been constantly associated with deficient waste management. That is the case of 19 municipalities from Goiás State that inappropriately disposed of 73% of the produced household waste. According to Law No. 12,305/2010, these municipalities must implement a waste management facility with MSW recovery and landfill diversions to minimize environmental impacts. Furthermore, a specific life cycle assessment tool was used to conduct an environmental assessment of different alternatives for a shared waste management system among the metropolitan municipalities. The results have shown that the current scenario has the largest environmental impacts in seven of 12 assessed impact categories, among them the global warming potential. In this scenario, final waste disposal has the greatest environmental impact, particularly due to unlicensed landfills. Conversely, anaerobic digestion with greater landfill diversions generates the lowest emissions in eight of 12 impact categories. This demonstrates the importance of anaerobic digestion and the compliance of the diversion targets established by the Brazilian National Plan for Solid Waste Management.