Carbon footprint calculations in the soil remediation sector: A comparative analysis

The CO2 Performance Ladder (CO2PL) is a CO2 management tool that helps companies in improving the environmental performance of projects and business operations. Since the summer of 2020, it can be applied to tenders for soil remediation projects commissioned by the Public Waste Agency (OVAM) of Flanders (Belgium). The CO2PL supports organizations in setting up a CO2 management system, calculating their carbon footprint and achieving CO2 reductions. However, at present, little information is available about the application of this instrument to the soil remediation sector. Carbon footprint calculators are already commonly applied to evaluate soil remediation projects, but have a narrower scope and system boundaries, as they are only meant to calculate the carbon footprint of soil remediation projects, and not of all business operations. Keeping these differences in mind, the CO2PL was compared with other evaluation tools (the CO2 calculator, the Sustainable Remediation Tool (SRT) and the Spreadsheets for Environmental Footprint Analysis (SEFA)), which are used to calculate the carbon footprint of soil remediation projects. The comparative analysis consists of a qualitative analysis and a quantitative carbon footprint calculation based on data from two case studies in Flanders (Belgium). The results show that besides differences in objectives, scope and required input data, the calculated carbon footprint of the remediation project differs between the instruments. Use of different conversion factors can result in significantly different results. Only some of these differences in the conversion factors are inherently related to regional differences. Especially for more complex remediation projects, in which less conventional techniques/materials are used, CO2 conversion factors are sometimes not consistent, or simply lacking. A systematic inventory of relevant emission factors, specific for the soil remediation sector, would improve the application of carbon footprint calculations and support the implementation of these kinds of evaluation instruments in the soil remediation sector.