Conventional substitution methods are expensive and go against earthwork and road construction regulations. If it is necessary to refill an excavated area, the original soil is returned. In general, it is necessary to apply treatment procedures to the soil, to improve its structure and reduce its water content before it is reinserted in the ground. This increases its density and bearing capacity and only then is it suitable for reinsertion. Separating, filtering, mixing, crushing and ventilating are all performed directly on the site using mobile equipment.