Qualitative and quantitative simulation of best management practices (BMPs) for contaminated megasite remediation using the SiteWise™ tool

Remediation activities, particularly in megasites, may induce substantial secondary environmental impacts that must be addressed for green and sustainable remediation (GSR) practices. Only limited studies are available quantitatively assessing the environmental footprint and environmental benefits of implementing Best Management Practices (BMPs) in megasite remediation. This study used the SiteWise™ tool, a quantitative environmental footprint assessment for scenario simulation and benefit quantification of BMPs, on a contaminated megasite in Hebei Province, China. We observed a considerable environmental footprint and energy from the remediation. Taking the final implementation alternative (Alt 1) as an example, which is characterized by combining multiple remediation techniques, the greenhouse gas (GHG) emissions reached 113,474 t, the energy used was 2,082,841 million metric British thermal units (MMBTU), and other air pollutant emissions (NOx, SOx, and PM₁₀) amounted to 856 t. Further BMP analyses highlighted the benefits of substituting the conventional solidification/stabilization agent with willow woodchip-based biochar, which could reduce GHG emissions by 50,806 t and energy used by 926,648 MMBTU. The overall environmental benefits of implementing all applicable BMPs in the remediation were significant, with a 66.85%, 50.15%, and 56.05% reduction in GHG emissions, energy used, and other air pollutants, respectively. Our study provides insights into quantifying the environmental footprint and exploring emission reduction pathways for contaminated megasite remediation. It also offers a feasible path for quantifying the environmental benefits of BMPs, promoting the development of GSR of contaminated sites.