This chapter provides an overview of the remediation technologies based on physicochemical processes. In addition to emerging technologies, innovative developments of traditional technologies are presented. There is a demonstration of the physicochemical methods useful for the remediation of soils contaminated with pesticides. A case study on full-scale application of in situ chemical oxidation on a site historically contaminated with chlorinated hydro-carbons is reported. Hydrogen peroxide combined with alternating well pumping ensured intensive mass transfer between the soil liquid phases (DNAPL lens and groundwater) and achieved significant contaminant removal.