Patent ID: 7001105

Claim:
An in situ method of reducing the concentration of a contaminate in soil to or below a target concentration that is deemed environmentally acceptable in an area in which the contaminant concentration in a surface layer of the soil exceeds the target concentration, the method comprising the steps of: determining a requisite volume of clean soil in vertical proximity to the surface layer such that blending the soil in the surface layer with the requisite volume of clean soil results in a substantially uniform contaminant concentration in the blended soil that is at or below the target; employing a mobile trencher apparatus modified to lift and churn soil in place to a depth of at least four feet to vertically mix the surface layer soil in the area with the requisite volume of clean soil in vertical proximity; running the mobile blending apparatus through the area under conditions to provide sufficient time for the mobile blending apparatus to blend the mixed soils so that the contaminate concentration throughout the blended soil is substantially uniform.