The impacts of remediation techniques on soil functions: a review

Abstract. Soil contamination is a major driver of soil degradation in Europe, and remediation practices are increasingly expected to support not only risk reduction but also the recovery of soil health and ecosystem services. In line with the European Soil Monitoring and Resilience Directive, this review evaluates how commonly applied remediation techniques impact key soil functions that underpin soil health. A structured narrative review of the literature was conducted to assess the impacts of conventional (physical and chemical) and low‑impact (biological and nature‑based) remediation techniques on six aggregated soil functions: organic matter storage and transformation, water regulation, nutrient cycling, contaminant retention and degradation, physical stability, and habitat provision. The analysis shows that conventional remediation techniques such as thermal treatment, soil washing, in‑situ chemical oxidation/reduction, and stabilization/solidification frequently achieve effective contaminant removal but often cause substantial and sometimes irreversible degradation of soil structure, organic matter, microbial activity, and habitat quality. In contrast, low‑impact remediation approaches, including bioremediation, phytoremediation, monitored natural attenuation, and immobilization with organic or selected inorganic amendments tend to preserve or enhance soil functions, although typically at slower contaminant removal rates and with strong site specificity. The review highlights critical knowledge gaps, particularly regarding limited information on specific remediation techniques and impacts on soil fauna, the limited availability of quantitative thresholds for when a soil can be considered healthy or unhealthy for performing various functions, and limited soil health assessments in urban and industrial context. Hybrid and adaptive remediation strategies that combine risk reduction with rehabilitation measures are identified as key to balancing risk reduction and soil functionality while also planning for refunctionalization at the onset as part of the soil health trajectory. Overall, embedding soil health as a central management objective is essential for sustainable contaminated land management aligned with European policy goals.