The removal of weathered-in PCBs from clayey soil by surfactant washing is demonstrated at bench scale. Spent surfactant solution was treated for recycle at bench scale by countercurrent liquid-liquid extraction for the removal of nonvolatile contaminants, and by thin film aeration in packed columns for removal of volatile organics. A correlation of micelle/water partition coefficients with octanoll water partition coefficients reported earlier by Valsaraj et al. is extended to several additional compounds. Mathematical models for batch-batch, batch-continuous flow, and countercurrent flow surfactant soil washing are described, and the effects of the model parameters are discussed.