Characteristics of environmental efficiency for different types of contaminated sites in China

The assessment of the environmental efficiency of contaminated sites is important to address funding issues and ensure the sustainability of redevelopment in remediation and risk control actions. This study aims to gauge the environmental efficiency of remediation and risk control (EERRC) levels in China. It utilizes the super-efficiency directional distance function and metafrontier model to estimate metafrontier and group frontier EERRC across 408 contaminated sites spanning 27 provincial administrative regions. These sites were categorized based on economic development levels and industry types. This study dissects inefficiency factors into technological gaps and managerial inefficiencies while also analyzing the impact of site categorical attributes and the correlation between remediation and risk control strategies and EERRC. Findings indicate that China's overall EERRC average under the metafrontier stands at 0.524, contrasting with 0.902 under the group frontier, showcasing crucial technological gaps among regions and industries. Notably, industries such as metal smelting and processing, energy processing and supply, and textile and tanning exhibit low EERRC owing to their high technological complexity and compound contamination of heavy metals and semi-volatile organic compounds. Regions with low economic development are advised to prioritize more effective risk control measures over indiscriminate remediation efforts. Moreover, this study suggests that repurposing contaminated sites for uses such as storage land or sensitive land (e.g., residential or public administration and service) in terms of land planning. The EERRC assessment is instrumental in formulating cleanup and redevelopment strategies tailored to diverse types of contaminated sites.