Toxaphene, produced by the chlorination of camphene, is a chlorinated hydrocarbon insecticide that was widely used to control a variety of insects on crops and to control livestock skin parasites. It is known to be a toxic and a highly persistent chemical in soil where its half-life can be in excess of ten years, depending on the environmental conditions. This study was conducted in an attempt to explain a finding in this lab of high concentrations of toxaphene (2600 ppm) in soil sampled at a depth of 1 m. The source of the sample was from a pesticide waste facility in northern California. The paradox of this discovery was that toxaphene, being hydrophobic, has been shown to be restricted in its movement from agricultural applications to a reported maximum of 30 cm, with the bulk of material concentrated in the upper 10 cm. Toxaphene is known to undergo anaerobic degradation that changes its gas chromatography profile. The toxaphene analyzed in this sample had an unweathered profile similar to technical toxaphene, implying that no degradation had occurred. Since a waste disposal facility is faced with abnormally high concentrations of pesticides and formulation components, it was of interest to ascertain if movementmore » in a soil profile was possible when such concentrations prevail in a waste facility.« less