Soil venting for site remediation after hydrocarbon pollution

Urban areas, utilized in past for stocking and distribution of oil products, inevitably presents phenomena of subsoil pollution. Such phenomena, also persisting after the end of industrial activities, involve conditions requiring interventions of environmental remediation. The present work analyzes the intervention procedures for the restoration of an area utilized as hydrocarbons deposit in an urbanized site of central Italy and of an area in the South of Italy, interested by a gasoline pollution due to underground storage tanks. Subsoil characteristics and its state of contamination have been preliminary investigated. Contamination has been located in two different layers, the first one extended in the vadose zone, the second one in the saturated zone. Specific interventions for the different delivery of pollution have thus been studied, that is: removal of the superficial contaminated soil; soil venting in the unsaturated zone of the subsoil; water pumping and treatment in the saturated zone. The soil venting system resulted particularly important and complex, therefore the execution of pilot test has been made necessary. The results of the performed pilot test have been analyzed and the relevant parameters in the final plant design for the area restoration have been thus selected.