Sustainability indicators for environmental geotechnics

Environmental geotechnics (EG) has the potential to make a substantial contribution to the field of sustainable construction, which in turn affects sustainable development. Indicators for measuring sustainable performance within the construction sector are well developed because the concepts have been around for many years. However, within the EG sector they are not, probably due to the combined difficulties of inherent site-specific complexity and scale. In addressing this shortfall, the aim of this paper is to present a new suite of environmental geotechnics indicators (EGIs). The new EGI system is formulated from existing construction sector indicators, from which a set of 108 separate indicators for assessing progress towards achieving greater sustainability are presented. Using a point score system (1 (harmful) to 5 (significantly improved)), the set of indicators can cover the entire timeline of a project in eight distinct stages (feasibility to long term). The set includes 76 ‘generic indicators‘ used to assess the sustainability of any geotechnical project and a set of 32 additional ‘technology-specific‘ indicators used to assess the sustainability of specific techniques for treating contaminated land. This latter indicator set can be modified, or substituted by any appropriate technology-specific indicator set, to address whatever geotechnical processes are proposed in a project. The final output of the assessment is an eight-pointed rose diagram that can be used to highlight areas of weakness within a project. The indicators within this new model are not split into various sustainability pillars (economic, social and environmental), thereby reducing the risk of an end-user focusing on the economic pillar alone. The indicators are applied to a case study site.