The aim of the paper was to evaluate the environmental burden of the organic waste management
systems implemented in Umbria region in Italy, in order to provide useful information for taking stra-
tegic decisions aimed at the improvement and optimization. The two most widespread scenarios were
analyzed: source-segregated collection followed by organic fertilizer production and not-differentiated
collection followed by mechanical and biological treatment and disposal in landfill of the biostabilized
material. The environmental performance was assessed through Life Cycle Assessment methodology,
assuming one ton of organic waste as functional unit. Most of data for life cycle inventory were provided
by actual facilities while background data were obtained from EcoInvent database. The alternative sce-
narios were compared through the IMPACT 2002þ method and the assessment was carried out on both
midpoint and endpoint levels.
Results showed that the landfilling of the undifferentiated organic waste has the least impact on the
analyzed impact categories, except on the Global Warming, mostly due to the uncollected methane
released by the landfill. As regards the aerobic composting of the source-segregated organic fraction, the
efforts to reduce the impact should be mainly focused on the reduction of the air emissions (hydrogen
sulfide, particulate, ammonia and NMVOC) from the biostabilization process.
Furthermore the sensitivity analysis indicated that the increase of the biogas collection efficiency could
significantly improve the performance of the not-differentiated collection scenario.