Using a hybrid LCA method to evaluate the sustainability of sediment remediation at the London Olympic Park

Remediation operations may have a wide range of environmental, social and economic impacts not only within the physical boundary of a contaminated site and over the operational period, but also across geophysical boundaries and beyond project life cycle. Life cycle assessment (LCA) has been increasingly used by both researchers and industrial practitioners in the ongoing green and sustainable remediation movement. This paper proposes a new hybrid-LCA method. In comparison with most remediation LCA studies in literature, the proposed approach offers several advantages by: 1) expanding the system boundary and reduces truncation errors; 2) incorporating consequential benefits (i.e. tertiary impact) of remediation; and 3) covering social and economic impact in addition to environmental impact. The hybrid LCA method is built on the 123 sector input-output analytical table and environmental account for the UK. The model was augmented with additional socioeconomic data (e.g. employment, occupational health and safety) to measure social and economic impact indicators. A sediment remediation project at the London Olympic Park site was examined using this method. The hybrid LCA was found to capture an additional 32% of secondary impact in soil washing, and 8% of secondary impact in landfilling. The tertiary impact was found to be over twice the primary plus secondary impact in soil washing, and nearly 80% of the primary plus secondary impact in landfilling. The quantitative social and economic impact assessment results also provided useful information for holistic decision making, balancing project costs with social and economic benefits.