Life cycle assessment of capital goods in waste management systems

•The importance of capital goods (machinery, buildings) was quantified by LCA.•Capital goods included: composting plant, anaerobic digester, incinerator and landfill.•Capital goods of bin and collection truck were included to assess the collection.•The most important contribution from the capital goods was from use of steel.•The contribution of capital goods to the total impacts of managing waste was significant.

The environmental importance of capital goods (trucks, buildings, equipment, etc.) was quantified by LCA modelling 1 tonne of waste treated in five different waste management scenarios. The scenarios involved a 240 L collection bin, a 16 m3 collection truck, a composting plant, an anaerobic digestion plant, an incinerator and a landfill site. The contribution of capital goods to the overall environmental aspects of managing the waste was significant but varied greatly depending on the technology and the impact category: Global Warming: 1–17%, Stratospheric Ozone Depletion: 2–90%, Ionising Radiation, Human Health: 2–91%, Photochemical Ozone Formation: 2–56%, Freshwater Eutrophication: 0.05–99%, Marine Eutrophication: 0.03–8%, Terrestrial Acidification: 2–13%, Terrestrial Eutrophication: 1–8%, Particulate Matter: 11–26%, Human Toxicity, Cancer Effect: 10–92%, Human Toxicity, non-Cancer Effect: 1–71%, Freshwater Ecotoxicity: 3–58%. Depletion of Abiotic Resources – Fossil: 1–31% and Depletion of Abiotic Resources – Elements (Reserve base): 74–99%. The single most important contribution by capital goods was made by the high use of steel. Environmental impacts from capital goods are more significant for treatment facilities than for the collection and transportation of waste and for the landfilling of waste. It is concluded that the environmental impacts of capital goods should always be included in the LCA modelling of waste management, unless the only impact category considered is Global Warming.