Background Soils, sediments and groundwater are sinks for many contaminating substances. The European Environment Agency (EEA) estimates that there are 300 000-1.5 million contaminated sites in the EU that could be cleaned up (i.e. the source of the contamination is no longer present). The total cost for the clean-up of these sites is estimated at €59-109 billion. However, there are also many sites where the source of pollution is still present, so the actual cost of cleaning-up contaminated sites in Europe will be a multiple of this. Major sources of contamination are chorinated aliphatic hydrocarbons (CAH), benzene, toluene, ethylbenzene and xylene (BTEX) and total petroleum hydrocarbons (TPH). These contaminants all have different chemical and physical characteristics and different means of biodegradation. This makes remediation of sites contaminated with a mixture of these chemicals difficult, expensive and time-consuming. Objectives The project’s objective is to demonstrate the applicability of an In-Situ Chemical Oxidation (ISCO) technique for the remediation of soil and groundwater contaminated with a cocktail of organic contaminants in very high concentrations at an explosion sensitive site (i.e. an EXrated site). Specific objectives include: To demonstrate the application of ISCO with perozone for the full scale remediation of soil and groundwater contaminated with a mix of different organic components in very high concentrations; To develop an extensive health and safety plan defining the necessary safety measures for the use of this technique at EXrated sites; To develop procedures for implementing the technique; To demonstrate the advantages of the technique in comparison with traditional remediation techniques (fewer carbon dioxide emissions; more time-, cost- and energy-efficient); and To evaluate the economic and environmental feasibility of the ISCO with perozone technique. Expected results: A significant reduction in contaminant concentrations in a relatively short period of time, using only a limited number of injection points; A report on the technical and economic feasibility of ISCO using perozone; An extensive health and safety plan for the use of ISCO at EXrated sites; and Two working procedures for implementing ISCO (one for the execution of the pilot test and one for full scale remediation), allowing transfer to other EXrated plants.