Life-cycle assessment applied to construction of Thames Tideway east tunnel, London, UK.

The Thames Tideway tunnel is a large sewer running up to 66 m below the tidal river Thames in London, UK. Its construction, started in 2016, was urgently needed to protect the tidal Thames from pollution due to the combined sewer overflows of untreated sewage that every year are spilled into the river. This paper reports on an exercise for evaluating the environmental impact associated with the construction process of the east section of the tunnel quantified by means of a life-cycle assessment, which not only primarily considered carbon dioxide emissions, but also took into account a wider series of impact categories. Operational and decommissioning impacts were not included. The results indicated the processes with the greatest effects on the environmental performance of the east sector construction and hence where alternatives on the design or materials used needed to be considered. [ABSTRACT FROM AUTHOR]