An evaluation approach for sustainable mega-site remediation in China integrated with remedial duration

Due to the fast-paced redevelopment of contaminated sites in developing countries, there is a lack of appropriate quantitative approaches to evaluate sustainability for the selection of remedial alternatives. In this study, an integrated evaluation approach for sustainability assessment, incorporating remedial duration, was developed and applied to the site remediation of a mega-size former iron-steel manufacturing facility in China. The traditional environmental, economic, and social assessments, consisting of 15 categories and 50 indicators for one in situ alternative and four ex situ alternatives, were performed as the first-tier evaluation, which was then integrated with the second-tier evaluation on the remedial duration. The findings revealed that advanced in situ treatments were associated with long duration of remedial activities, preventing stakeholders from attaining timely benefits after successful land redevelopment. Furthermore, sustainable development goals (SDG) were correlated for the evaluation of sustainable remediation, supporting the conclusion that the On-site/Off-site treatment alternative performed well in both sustainability and timely redevelopment demands. The scoring of alternatives was further validated through uncertainty analysis, which demonstrated that the On-site/off-site treatment alternative had the highest probability of attaining the best sustainability performance. In addition, sensitivity analysis revealed that remedial duration had the strongest correlation and sensitivity in the integrated evaluation. Integrating SDG targets with the sustainable remediation concept promotes the greatest net benefit from implementing a sustainable and resilient remediation strategy. Practically, this study proposed an integrated model to promote sustainable remedial outcomes for contaminated sites in fast-developing countries and markets, considering the constraints of remedial timeframes and the pursuit of ecological functions.