Abstract: A trickling filter system to treat contaminated soil, and prevents its migration, comprises: a reactor vessel having a floor, a side wall or walls, and a cover, to contain the soil; a contaminated soil bed received into the vessel and onto the vessel floor; a raking apparatus including rake arms in the vessel and a drive therefore, to displace the arms for raking the soil; and a sprinking system in the vessel to sprinkle liquid into the raked soil, and; a sump associated with the reactor vessel to receive liquid that drains from the soil, and to supply that liquid to said sprinkling system, the liquid including water and organics dissolved in the water.