A system for washing contaminated sand comprises a plurality of reactors arranged in a sequence from a first to a last reactor. The first reactor is configured to receive contaminated sand. Each reactor comprises a funnel portion in a lower section thereof for accumulating a sand layer and a sand conveying device for removing sand through an aperture defined near a bottom of the funnel portion. Each reactor except the first reactor receives sand removed from a previous reactor. The system also comprises a steam supply system for providing each reactor with steam for washing the sand, a water supply system for providing the last reactor with clean water for rinsing the sand, and a fluid outlet associated with each reactor for removing fluid and providing the fluid to a separator for separating the fluid into first and second portions respectively containing relatively low and high proportions of hydrocarbons.