Abstract: A process and apparatus for the remediation of soil is provided with a plug flow of soil and counter-current wash of water. The contaminant-containing soil with water is first treated to disengage the contaminant from the soil and form a liquid phase containing water and contaminant. The treated soil and liquid phase is continuously introduced into a wash zone at a first end of the wash zone, and the soil and the liquid phase are conveyed in successive and discrete portions through the wash zone between the first end of the wash zone and a second end of the wash zone to provide an essentially plug-flow of the soil through the wash zone.