Municipal solid waste (MSW) management remains a critical challenge for local authorities transitioning toward circular models. Although separate collection rates have significantly improved over recent decades, achieving complete source separation is structurally unattainable. This results in the generation in an unavoidable stream of unsorted residual MSW (UR-MSW). Nevertheless, the quality of UR-MSW can be substantially enhanced, as it frequently contains valuable recyclable and compostable materials that are improperly diverted to energy recovery or landfill, leading to missed recovery opportunities, higher disposal costs and increased environmental impacts. This study presents the results of the T.Ri.Plus project, an experimental program implemented in the Salerno District (Southern Italy) in collaboration with the Italian National Packaging Consortium (CONAI). A comprehensive waste composition analysis was conducted on UR-MSW entering a Mechanical and Biological Treatment (MBT) facility through two analytical campaigns in 2021, totaling 124 compositional analyses across 32 pilot municipalities. Results reveal a persistent paradox: even municipalities characterized by high separate collection performance generate UR-MSW streams in which more than 50% by weight consists of technically recoverable materials. These include biodegradable fractions for anaerobic digestion or composting and over 35% inorganic recyclables like paper, plastics, glass, metals and wood, effectively reframing residual waste as a high-potential “urban mining”. These findings were translated into economic and environmental assessments. Within the Extended Producer Responsibility (EPR) framework, the analysis demonstrates and quantifies how inadequate waste separation prevents municipalities from intercepting the economic transfers established under the ANCI–CONAI National Framework Agreement. This leads to quantifiable foregone revenues while simultaneously exacerbating measurable and avoidable landfill disposal and incineration costs. A Life Cycle Assessment (LCA) confirmed that substantial reductions in environmental impacts are achievable when materials are correctly valorized. Overall, the analysis demonstrates that quantity-based indicators alone are not sufficient and territorial factors strongly influence UR-MSW composition. The T.Ri.Plus framework reframes residual waste as a reservoir of hidden value and shows that quality-oriented collection strategies, leveraging EPR mechanisms, can generate measurable benefits while supporting EU packaging recycling targets. Keywords:
Lost Value and Hidden Costs in Unsorted Residual MSW: Economic and Environmental Consequences of Improper Waste Separation – A Case Study
Giovanni Marmora
;Giovanni De Feo
2026
Abstract
Municipal solid waste (MSW) management remains a critical challenge for local authorities transitioning toward circular models. Although separate collection rates have significantly improved over recent decades, achieving complete source separation is structurally unattainable. This results in the generation in an unavoidable stream of unsorted residual MSW (UR-MSW). Nevertheless, the quality of UR-MSW can be substantially enhanced, as it frequently contains valuable recyclable and compostable materials that are improperly diverted to energy recovery or landfill, leading to missed recovery opportunities, higher disposal costs and increased environmental impacts. This study presents the results of the T.Ri.Plus project, an experimental program implemented in the Salerno District (Southern Italy) in collaboration with the Italian National Packaging Consortium (CONAI). A comprehensive waste composition analysis was conducted on UR-MSW entering a Mechanical and Biological Treatment (MBT) facility through two analytical campaigns in 2021, totaling 124 compositional analyses across 32 pilot municipalities. Results reveal a persistent paradox: even municipalities characterized by high separate collection performance generate UR-MSW streams in which more than 50% by weight consists of technically recoverable materials. These include biodegradable fractions for anaerobic digestion or composting and over 35% inorganic recyclables like paper, plastics, glass, metals and wood, effectively reframing residual waste as a high-potential “urban mining”. These findings were translated into economic and environmental assessments. Within the Extended Producer Responsibility (EPR) framework, the analysis demonstrates and quantifies how inadequate waste separation prevents municipalities from intercepting the economic transfers established under the ANCI–CONAI National Framework Agreement. This leads to quantifiable foregone revenues while simultaneously exacerbating measurable and avoidable landfill disposal and incineration costs. A Life Cycle Assessment (LCA) confirmed that substantial reductions in environmental impacts are achievable when materials are correctly valorized. Overall, the analysis demonstrates that quantity-based indicators alone are not sufficient and territorial factors strongly influence UR-MSW composition. The T.Ri.Plus framework reframes residual waste as a reservoir of hidden value and shows that quality-oriented collection strategies, leveraging EPR mechanisms, can generate measurable benefits while supporting EU packaging recycling targets. Keywords:I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
